This PDF file contains the front matter associated with SPIE Proceedings Volume 12309 including the Title Page, Copyright information, and Table of Contents.

To get a deep understanding on the relationship between process parameters of multi-layer laser cladding and performances of the coating, a Al₂O₃-13 wt.%TiO₂ nanostructured ceramic coating was prepared by quash presetting multi-layer laser cladding. Effects of three major parameters (closed loop control temperature of molten pool, ultrasonic vibration frequency and preheating temperature of incubator) on bonding strength of coating were analyzed in the laser cladding experiment through 3-factor and 3-level orthogonal experiments. Moreover, process parameters of laser cladding were optimized. Results demonstrated that closed loop control temperature of molten pool was the dominant influencing factor of bonding strength of coating, followed by preheating temperature of incubator and ultrasonic vibration frequency successively. The optimal process parameters for preparing the Al₂O₃-13 wt.%TiO₂ nanostructured coating through multi-layer laser cladding include closed loop control temperature of molten pool=2500 ^oC, ultrasonic vibration frequency=50 kHZ and preheating temperature of incubator=400 ^oC. The bonding strength of coating after process parameters optimization reached 66.3 MPa.

By analysing the technical requirements for the installation of SAFT lithium batteries imported from France, combined with the practical experience of the model, a complete installation process and method are proposed, and a heat conduction installation method based on large-format insulation technology is proposed. The operating technology are summarized to meet the needs of imported lithium battery installation. The technical requirements play a guiding role in realizing the reliability and efficiency of the operation.

Aiming at the problem of information fault from digital design to manufacturing in the whole product life cycle, a three-dimensional digital manufacturing implementation mode integrating design, process and manufacturing is proposed to realize the comprehensive integration and integration of information. On the design side, the standard files are constructed based on feature extraction, reconstruction and lightening technologies. On the process side, the MBD design and process model are integrated to build a three-dimensional process integration information model. On the manufacturing end, based on the unified standardized data interface table, three-dimensional visual monitoring is carried out for the whole process of product production and equipment operation, so as to realize heterogeneous collaboration, interconnection and transparent control from product design to manufacturing, and provide strong support for the digital transformation of manufacturing industry.

In the current situation of increasingly tense resources, doubled environmental pressure and tightening environmental protection policies, iron and steel enterprises should achieve the goal of energy saving and emission reduction, and further enhance the core competitiveness of enterprises to adapt to the development of society. In the process of modeling, the current BF ironmaking process mainly considers the BF's compliance, less consideration of the change of industrial metabolites, so it is necessary to build a more comprehensive BF model. Through the analysis of the operation of the internal substances in the blast furnace, the industrial metabolism network is constructed. Through the multi-agent simulation, the concentration of blast furnace materials and the reaction speed are predicted. On this basis, the industrial production is regulated to achieve green and efficient development.

This study optimized laser cladding process parameters by combining BP neural network (BPNN) and genetic algorithm (GA) based on the multi-layer cladding nano Al₂O₃-13 wt.%TiO₂ coating. The model structure was trained according to the orthogonal test results. The BPNN model of closed loop control temperature of the molten pool, ultrasonic vibration frequency and preheating temperature of the incubator with bonding strength and microhardness of the coating was constructed. Moreover, single-objective and multi-objective parameter optimizations were carried out to bonding strength and microhardness of the coating based on GA. Results demonstrated that the predicted values of models are very close to test values, indicating that the constructed model was accurate and reliable. The maximum bonding strength and the maximum microhardness of the coating after GA optimization are 70.7 MPa and 2025.5 HV, respectively. When weights of bonding strength and microhardness of the coating are the same, the coating achieved the optimal comprehensive performances under the 2472.0 ^oC of closed-loop control temperature of the molten pool, 31.9 kHZ of ultrasonic vibration frequency and 400 ^oC of preheating temperature of incubator. The corresponding bonding strength and microhardness are 69.1 MPa and 1835.5 HV, respectively.

The application of digital twin technology in the field of automotive welding is fragmented and not systematic. This paper summarizes the previous experience of digital twin project implementation and analyses that digital twin technology can effectively support automotive products from product design to production. The whole process of management, and then design the integrated application architecture of digital twin technology in the field of automobile welding, including three-level systems, namely database layer, collaborative operation platform, application software layer, with 12 functions, oriented to 7 types of use service.

Additive manufacturing utilizes a layer-by-layer stacking method to process parts, which simplifies the manufacturing process. But the staircase effect has a great impact on the accuracy of surfaces, so it is necessary to select some reasonable building orientations considering different types of features and tolerance requirements. This paper uses the Open CASCADE Technology to identify the tolerance, topological shape, and geometric object in the STEP AP 242 file format and selects a reasonable building orientation set for required model sub-features according to the geometric characteristics of different kinds of topological shapes. The precision value of each building orientation in the set is calculated by tolerance weighting, and the value ranking of each orientation for ensuring surface accuracy is obtained, which can be used as a reference for the subsequent determination of the building orientation. Experiments on 10 models are conducted to verify the effectiveness and rapidity of the proposed method.

The residual stress on the machined surface has a significant impact on the service performance of the parts and needs to be well predicted. However, considering the existing research, the experimental method is expensive and the analytical method is complex to predict the residual stress. Although the existing finite element method can be used to predict the residual stress, its simulation accuracy is not high to meet the requirements for the residual stress optimization. Therefore, based on the J-C constitutive model of aluminum alloy 7075-T6, the simulation model of residual stress on the milling surface of aluminum alloy is established by AdvantEdge cutting simulation software. The experimental results show that the average simulation error of residual stress in 𝑥 and 𝑦 directions is 9.8%, which verifies the proposed finite element model. Based on the finite element model, the effects of milling process parameters on residual stress are analyzed. Then, the residual stress samples are generated by the finite element model to reduce the cost and period of the experiment. And GRNN is established to predict the residual stress based on generated data samples. The prediction accuracy generated by GRNN reached more than 80%. Based on the GWO algorithm, a process parameter optimization method is proposed for minimum surface residual stress. The optimal process parameters are spindle speed 7200r/min, feed rate 0.1mm/z, depth of cut 1.4mm, and 𝜎_xx is 105.68 MPa, 𝜎_yy is 64.82 MPa. The proposed method provided a basis for improving the service performance of parts by optimizing the surface residual stress.

In order to meet the process requirement of ≤4 s·piece^-1 for punching the pin-joint chain plate, a multi-station continuous punching device for bent chain plate was designed, which mainly consists of feeding mechanism, punching die, scrap cleaning mechanism, unloading mechanism and rotary mechanism, etc. It can continuously complete the work of four stations, such as feeding, punching, scrap cleaning and unloading of bent chain plate. Firstly, according to the process flow of multi-station continuous punching for bent chain plate of pin-joint chain, the action requirements of multi-station continuous punching device were analyzed. Then, the motion planning and time sequence division of each action were divided. Finally, a simplified simulation model of multi-station continuous punching device for bent chain plate was established in ADAMS software, and the motion simulation of multi-station continuous punching process was carried out according to the timing sequence planning. The force, moment and displacement curves of each moving part were obtained. The simulation results show that the motion planning of the multi-station continuous punching device for bent chain plate is reasonable.

Taking the assembly accuracy prediction in the virtual assembly process of parts as the research target, and the automatic generation and solution of the three-dimensional assembly dimension chain as the research object, the automatic generation and solution technology of assembly dimension chain considering the fit deviation is proposed. By preprocessing the selected assembly model, the basic information of the relevant parts is obtained and stored in the corresponding chain table; Based on the response function of UG secondary development, the obtained data are processed, and according to a certain search direction, the increasing link and decreasing link are determined, and the dimension chain is generated; According to the dimension chain output by the result, the relevant information of the seal ring is calculated, so as to realize the prediction of assembly accuracy. Taking the assembly of the Y-axis screw of the CNC machine tool as an example, the prediction function of the assembly accuracy of the established system is verified, and the validity of the research method is confirmed.

Artificial hummingbird algorithm is a new MH algorithm with a simple mechanism and is easy to implement. It shows a strong competitive edge. However, when solving complex multimodal and engineering design problems, the AHA has disadvantages such as being easy to fall into local optimum and slow convergence speed. Therefore, an effective AHA (JOS-MrAHA) based on mirror reflection learning and joint opposite strategy is proposed in this paper. First, a mirror reflection learning based on the reflection principle is introduced to expand the search area and enhance the search capability. In addition, by adding the joint opposite strategy, the ability of JOS-MrAHA to jump out of the locally optimal solution is enhanced, and the convergence speed is accelerated. In addition, JOS-MrAHA and three latest MH algorithms are used to solve the CEC2019 test suit. The evaluation metrics obtained by JOS-MrAHA are generally better than the other three MH algorithms. Finally, JOS-MrAHA is applied to the rolling element bearing problem, and the numerical results verify the applicability and high efficiency of JOS-MrAHA in solving rolling element bearing mechanical problems.

With the aim of mitigating workload imbalance among workers, this paper optimizes multi-skilled worker and task assignments with the consideration of lot-splitting. A mixed-integer nonlinear programming model is proposed to minimize the maximum workload of workers. To verify the effectiveness of the proposed model, the model without lot-splitting is used for comparison. These models can be linearized and solved by optimization solver CPLEX. Computational experiments show that our fairness-oriented model has better performance on mitigating the workload imbalance while maintaining high production efficiency.

Line structured light (LSL) measurement systems have gained more and more applications in industry. An interested profile can be easily obtained through the analysis of laser-object intersection stripe. However, all stripe center extraction methods have extraction errors which will lead to profile deviation from the ideal one. In order to reduce this error, the law of uncertainty generation and propagation for the LSL measurement system is analyzed, and a filtering procedure is carried out on this basis. The uncertainty of stripe center extraction is computed in real time by adaptive BP neural network (ABPNN). According to the measurement model and the uncertainty propagation law, the uncertainty value of the each measurement point is obtained. Then, a point cloud filtering method based on uncertainty is proposed. The surface equation is obtained by segmenting and weighting the original point cloud, and the new point cloud data is obtained by interpolation calculation. Finally, the filtered point cloud data is verified by experiments, which proves that the filtering method can improve the measurement accuracy.

Cultural Statues like other culture relics are important for cultural inheritance and education. While they are gradually damaged by the natural environment. In order to protect and repair these kinds of cultural statues and other cultural relics, many experts have used terrestrial three-dimensional(3D) Laser Scanning (TLS) technology to construct culture relics 3D model. With the development of the photogrammetry, Unmanned Aerial Vehicle (UAV) photogrammetry have made some progress in hardware and software. It is also a good modeling method, but there are few application examples of cultural heritage protection. It adopted these two methods to construct fine 3D model research on the cultural statue- Confucius statue, respectively. Based on Leica C10 3D laser scanner technology, a fine 3D modeling of Confucius statue is constructed based on point cloud data by software Geomagics. Meanwhile, multi-angle images were collected by DJI Phantom 4Pro UAV photogrammetry system, and a fine Confucius statue 3D modeling was constructed by software ContextCapture (CC), which is one kind of popular modeling software based on images. Finally, it used a high precision Total Station (TS) to measure some test points of the research object, the precision of the two fine 3D models constructed by the above two methods were evaluated. The results showed that both methods could achieve the requirements of the cultural statues fine 3D modeling. The precision of the model constructed by TLS was higher than UAV one. While the latter has more obvious advantages in efficiency. During these kinds of cultural statues or relics modeling, according to the flight condition, two methods can be combined to construct fine 3D model to balance the precision and efficiency. It can provide reference for the protection of other cultural relics.

In order to achieve rapid response to process changes in the control programming of reconfigurable precision assembly systems, this paper proposes an assembly process control information optimization method based on assembly skills. Based on this, the optimization of the control information of the assembly control process through the established assembly macro-action information model is proposed, which provides an important basis and support to further realize the automatic generation of control sequences for intelligent assembly systems. Firstly, the problems of repetitive structure and complicated information in existing assembly sequence generation were analyzed, and assembly process was represented as assembly skill sequence by assembly control process representation method based on assembly skills. Then, the PMA sequence is rapidly generated by macro expansion. Finally, this method is applied to the control process of the actual micro-assembly system.

In recent years, as smart manufacturing becomes mainstream, digital twin have received a great deal of attention from industry and academia. In this work, data is retrieved in Web of Science with keywords = smart manufacturing and digital twin from 2017 to April 2022. CiteSpace is used to visualize and analyze the application of digital twin in smart manufacturing. In addition, the research focuses and deficiencies in this field are expounded, and corresponding suggestions are put forward.

The drainage consolidation method has merits of low expense and short construction period in the treatment of deep soft soil foundation. In this study, the structural properties of soft clays in the coalfield of a power plant were simulated in a zoning fashion during numerical calculation. Moreover, the axisymmetric problem of the vertical drain foundation was converted into a plain strain problem for finite element analysis. The actual measurement results are basically accorded with calculation results, indicating that the drainage consolidation method is reasonable and effective in treating coalfield deep soft soil foundations.

In view of the problems commonly existing in the truck outsourcing team of open-pit coal mine, such as complex personnel identity, employment without certificate, employment with expired contract, insurance, health certificate and other documents, and even the re employment of personnel who have made serious mistakes, combined with the characteristics of truck operation in open-pit coal mine, this paper puts forward two kinds of intelligent management and control technologies and equipment for trucks and drivers. The first technology and equipment adopts the way of deploying intelligent monitoring and inspection posts at the operation site, and adopts Bluetooth transceiver technology to effectively control trucks and drivers. The intelligent inspection posts cooperate with the monitoring center to form a regional management and control system. The second technology and equipment adopts the way of distributing intelligent terminals to all trucks and truck drivers, and adopts video intelligent technology to realize the intelligent control of trucks and drivers. The intelligent terminals and the monitoring center form a full-scale dynamic supervision network to effectively ensure the production safety of the whole area. The two control technologies and equipment are comprehensively evaluated, and the development direction of intelligent open-pit coal mine is prospected.

The high power transistor is an important component of the power driving circuits, which is usually worked under critical parameters. In this paper, the studied on manufacturing process of the base diffusion and emission diffusion have been proposed, which mainly focuses on parameter requirements of a special high power transistor. And the parameters of base diffusion and emission diffusion has been determined.

Phenol, as one of the organic pollutants in wastewater, is difficult to degrade, which will bring great problems to the environment and people. Ozone catalytic oxidation has a good effect on degradation of phenol. Bimetallic catalysts have been widely concerned in the degradation of phenol because of their high efficiency and low cost. In this work, flexible SiO₂ ceramic fiber membranes were prepared by electrospinning. Through impregnation, Fe₂O₃ and MnO₂ particles are also successfully loaded onto the SiO₂ fiber. Scanning electron microscope (SEM), X-ray diffraction (XRD), and Automatic specific surface area analyzer (BET) were used to characterize the material. Fe₂O₃-MnO₂ @ molecular sieve /SiO₂ has good catalytic activity for degradation of phenol. In this paper, a composite material of bimetal catalyst was developed. It provides a simple and effective method for the development of bimetallic catalytic materials for the degradation of phenol by ozone. The material is expected to be used in wastewater treatment.

The current development history of the drive-by-wire chassis is summarized, the composition and principle of the driveby- wire chassis are introduced, and the steering-by-wire system, the composition, working principle, control method and research status of the drive-by-wire system are analyzed in detail. The key technologies affecting the development of the drive-by-wire chassis are summarized, and the multi-sensor fusion positioning technology, fault-tolerant control technology, and vehicle wireless communication technology are reviewed.

Developing and testing control system for Autonomous Underwater Vehicle (AUV) is a costly and time-consuming task that requires extensive outdoor sailing tests. Aiming at the needs of AUV motion control algorithms design and performance evaluation and improving the development efficiency, a Hardware-in-the-Loop (HIL) simulation platform for AUV control with simple structure was designed by adopting the method of Model Based Design (MBD). And then, the feasibility of using the platform for algorithm design and preliminary verification is verified by a heading depth control test result.

The PBA method is essential to master vertical earth pressure distribution law in the subway station construction in the loess layer. Based on the engineering background of the Hejiaying Station of Xi'an Metro, this paper investigates the vertical earth pressure distribution of headings and buckle arches under different construction sequences based on numerical simulation and compares them with measured on-site data. The research results indicate the following. (1) The vertical earth pressure at the arch springing of headings A and D in the upper layer is approximately 1.06 times the vertical earth pressure at the arch crown. Moreover, the vertical earth pressure at the arch springing of headings B and C in the upper middle is approximately 1.015 times the vertical earth pressure at the arch crown, signifying that the vertical earth pressure at the middle heading B and C is more evenly distributed. (2) Comparing the different excavation sequences of the same layer of caves, the two sequences "excavating the upper layer first and then the lower layer" and "excavating the lower layer first and then excavating the upper layer" have a more significant impact on the vertical earth pressure of the headings. The heading initially excavated bears the slightest vertical earth pressure. (3) If Scheme 2 is applied to construct the buckle arch, the vertical earth pressure at the junction of the buckle arch and the heading is relatively large, approximately 1.69 times the vertical earth pressure of the buckle arch. Meanwhile, if Scheme 1 is applied for buckle arch construction, the force on the upper part of the buckle arch is relatively uniform. However, the earth pressure on the top of the arch is more significant than that of Scheme 2. It signifies that the earth pressure at the middle part of the arch is mainly transferred to the two ends of the arch when construction is performed using Scheme 2.

In the mechanical manufacturing industry, the detection of wrong and missing installation of threaded steel wire is of great significance and ensures the reliability and quality of products. Especially in aerospace engineering, the traditional detection of wrong and missing installation mostly adopts two-dimensional detection technology, which has the problems of poor detection effect and affected by light source. Aiming at this problem, a detection method of wrong and missing installation of threaded steel wire based on pointnet++ was proposed, which constructs a network framework based on pointnet++, by training the network, it realizes the recognition and direction judgment of threaded steel wire, and the accuracy is more than 95%.

Aiming at the problem of insufficient durability testing of thermal energy meters, a durability testing and quality analysis platform with complete functions and high degree of automation is developed and designed. In order to verify the monitoring accuracy and stability of the platform system, the performance test and quality analysis were carried out for the real-time performance of the platform system, the repeatability and reproducibility of the measurement system, and the effectiveness analysis are conducted according to the judgment criteria to ensure the safety and reliability of the platform system and meet the performance and quality requirements of the heat meter.

Industrial robots need to perform more complex manufacturing actions. The original teaching programming is gradually replaced by offline programming due to low accuracy, high personnel safety risks, and teaching difficulty. Various offline programming software is studied explore the specific advantages of offline programming compared to teaching programming. Through the research and analysis of robot kinematics, collision detection algorithm, and post-processing in offline programming, the technical differences between dedicated and general offline programming software are pointed out; RobotMaster and RobotArt are used to plan the grinding path offline for workpieces, and offline programming under different technologies is analyzed. The programming process of the software and the characteristics of the generated program, and the prospect of the development of the robot offline programming technology are prospected.

Nowadays, daily vital sign monitoring can effectively prevent chronic diseases and has a very important position in the field of medical research. However, the monitoring method is basically contact-based, which causes inconvenience to the daily life of users. This work presents a set of integrated real-time monitoring device system for respiration, pulse, and blood pressure based on the characteristics of non-contact and wide range of milli-meter wave radar. The device obtains data by monitoring the wrist of the human body in a relaxed state. Through image processing and machine learning, the respiration and pulse waveforms with good accuracy are separated, and the obtained blood pressure value also has a certain accuracy. The milli-meter wave radar itself has the advantages of low power, simple circuit, and good integration, so the device has a great market prospect.

Storage battery is one of the essential equipment in substation. Its operation stability directly affects the safety and reliability of substation. In recent years, the internal "false open" problem often occurs in the storage battery used in 220 kV substation. In this paper, the most common type of storage battery used in 220 kV substation has been analyzed, and its structure also has been analyzed. In view of the "false open" fault cases of storage battery used in 220kV substation in recent years, the most typical case has been selected, and the in-depth analysis was carried out from operation mode, test data and fault causes. At the same time, combined with the test data, the improvement measures for the "false open" problem of storage battery have been put forward from handover test, routine test and operation management. The relevant results of this paper can provide theoretical and data support for improving the safe and reliable operation of power storage in 220 kV substation.

In view of the problems of easy loss of satellite signals and divergence of inertial navigation system in navigation, various assisted navigation methods have emerged. Geomagnetic matching navigation has gradually become an important part of integrated navigation due to the characteristics of concealment, all-weather and no accumulation of errors. Traditional matching algorithms are sensitive to heading error and initial position error. Moreover, the intelligent algorithms are computationally complex and cannot meet the real-time requirements of navigation. Therefore, combined with the affine model, this paper proposes a scale-adaptive tower search method for geomagnetic matching navigation. This method selects the initial matching points by contour constraints, which improves the search efficiency. In addition, matching evaluation indicators are introduced to dynamically adjust search scales, which achieves both global searching and local positioning. The simulation results verify that the method can effectively correct the error of the inertial navigation system, and can meet the real-time requirements while ensuring the matching accuracy.

Aiming at the problems of small bandwidth, phase lag and high coupling in the longitudinal control system of traditional fixed wing UAV, from the control architecture and control strategy, this paper proposes a direct lift control based on nonlinear dynamic inverse/disturbance observation realizing the design of direct lift model and vertical fuselage transition model. This paper improves the direct lift control system from two aspects: the design of lift mode and the design of observer. The simulation results prove that the designed direct force control strategy has strong robustness and landing accuracy. Advanced features have greatly improved the success rate of automatic landing of carrier-based aircraft.

Under the goal of achieving carbon peak by 2030 and carbon neutralization by 2060, the nuclear power industry will play a more active role in the of clean energy in China. Due to the particularity of nuclear power plants, the seismic performance requirements of nuclear power equipment are high. In order to study the multi-dimensional seismic response of intelligent multi-processing display unit in nuclear power equipment, this paper carries out shaking table test including dynamic time history excitation with five OBE and one SSE, and two dynamic characteristic tests at the beginning and end of the test. The shaking test results show that the amplification factor in Y direction of the equipment is bigger than X and Z directions. The amplification factor in Y direction is between 1~1.5 indicating significant dynamic amplification effect, which should be considered in the seismic design of the equipment. Finally, two different types of intelligent multi-processing display unit work well under all the test conditions, meeting the seismic requirements.

In recent years, with the development of solid state physics and material science, refrigeration equipment with thermoelectric parts as the core has been widely used in aerospace, military, production and life. In this paper, the traditional medical specimen transport box was investigated and analyzed in the transport process, and it was found that the traditional transport box had many deficiencies. Therefore, our research group designed a new type of medical specimen transport box according to Peltier effect. The medical specimen transport box based on Peltier effect is mainly composed of four modules: power supply module, temperature difference cooling module, temperature control and display module and heat dissipation module. Compared with the traditional specimen transport box, the specimen transport box has the advantages of small volume, easy to carry, long temperature control time, green environmental protection, low price and so on, and has a good prospect for future development.

Precedent studies have only qualitatively assessed the comfort of defecation, which restricted the design and development of new toilet appliances. Aiming at the two difficulties of quantification of the defecation comfort level and low adaptability of existing toilets, this paper proposes a regression model for the quantitative relationship between joint comfort and height. And based on the model data, an adjustable lift pedal is designed. To obtain the relationship between height and optimal foot lift height, we simulated defecation posture based on the Jack software. A regression analysis was performed on the obtained data, and the results showed that the two were linearly correlated, with R2=0.9999. We calculated that the adjustable height difference required for the lift pedal is 19.583758cm. Finally, according to the data of the established model, the mechanism synthesis to the lifting pedal is carried out, and the relationship between the parameters of each component is deduced.

The DFH-4E satellite layout has a large and complex payload, a large weight, and a high longitudinal centre of mass, which brings greater difficulties and risks to hoisting command and docking operations. This paper analyzes the technical difficulties in the process of satellite assembly operations-satellite horizontal docking and hoisting, and summarizes and refines the skills and methods of its hoisting operations. While successfully solving the technical problem of DFH-4E satellite aerial horizontal docking at the final assembly site, it achieved the purpose of escorting the development of satellites, and the formed operation methods and skills provided experience and data support for subsequent hoisting tasks.

In order to research the effect of creep behavior and creep mechanical property of composite solid propellant on the structural integrity of long storage solid rocket motor, the semi-electronic compression creep experimental device and experimental method are designed. Then short-term and long-term compression creep experiments were carried out. Based on the experimental results, the compression deformation law of propellant was analysed. The results show that in the short-term compressive creep experiment, the stress-strain relationship of the propellant is still in the linear stage under the stress level of 0.5MPa. In the long-term compressive creep experiment, the stress-strain relationship is obviously nonlinear at the stress level of 0.25MPa. Long-term creep can result in a substantial reduction in propellant failure stress. Long-term creep will lead to large deformation of the propellant and plastic deformation even at relatively low stress level, which will adversely affect the motor structure.

The bearing of a large-scale equipment in a chemical plant broke down in the process of operation. The outer ring of the bearing was found cracked after downtime. In this paper, the failure analysis for the cracking cause of the bearing ring is carried out by means of macroscopic inspection, chemical composition analysis, hardness testing and metallographic examination. The results show that the main reason for the cracking failure of the bearing ring is the contact fatigue cracking of the bearing ring under the joint action of contact stress and alternating stress in service.

To solve the problem of missing assembly, a non-contact detection algorithm for assembly quality was proposed based on PointNet++ and point set registration. Firstly, the contour information of the target component was preprocessed using filtering and a local limiting filtering algorithm, and the contour data was sampled down and the contour peaks were processed. Then, the target contour was identified by the PointNet++ network. Finally, the point set registration method was used to register the target contour with the standard point set, and then the desired contour assembly information was obtained. Taking the engine cylinder valve as an example, the experimental results show that this method can effectively identify the assembly quality of the target component.

Aero-engine maintenance mode was transferred from the prescheduled maintenance to the condition-based maintenance. The condition-based maintenance can help to improve the engine reliability and reduce the maintenance costs. The study of the condition monitoring system was the key step of the condition-based maintenance. According to the characteristics of aero-engine high speed signal, this paper designs monitoring system. Firstly, the foreign experience of aero-engine condition monitoring system was learned. The structure, functional requirements and selection of monitoring events were proposed for a condition monitoring system, and then the principle prototype and its simulation platform of airborne condition monitoring system were implemented, which was helpful to the condition monitoring system study.

This paper takes a light off-road vehicle as the research object, analyzes the stress of the vehicle, and calculates the strength and stiffness of the rail. UG software on the left and right longeron, five beams and longitudinal, beam connecting plate and so on for 3d solid modeling and assembly. The difficulties and solutions in modeling are analyzed.

Handheld line structured light scanning system (SLSS) is a convenient choice to get the three-dimensional data of the objects. However, its accuracy is dominated by the calibration process and the extrinsic parameters of the handheld device. The extrinsic parameters are computed in real-time manner and connect the sensor coordinate system and the world coordinate system. However, significant noises can be observed due to the ambient light. To improve the accuracy, Kalman filter method is adopted and smoother extrinsic results of the handheld device can be achieved. This would also benefit for the final measurement results. The simulation and the experimental results further validate the effectiveness of the proposed method.

To improve the service performance and life of the pavement, the influence of the compaction degree of semi-flexible pavement materials on the pavement quality was studied. Taking semi-flexible pavement materials as the research object, the research on compaction characteristics in plateau environment is carried out, the formation mechanism of the strength of semi-flexible pavement materials is studied based on the Moore-Coulomb theory, and the unconfined compressive strength and porosity tests are carried out by the orthogonal test method. The test results show that the compressive strength and porosity of the number of compaction simulations have high significance. The compressive strength increases first and then decreases with the number of compaction simulations. The peak value reaches 2.98MPa when the number of compactions is 140 times. The overall change in the number of compaction simulations showed a downward trend, and the compressive strength first increased and then decreased with the compaction density, and the density reached a peak value of 92.69% (the void ratio was 7.24%). This research can provide a basis for the calculation of the material compaction work at low temperatures and the determination of the process parameters of the road roller.

The aim of this paper is to design the novel oil-air distributor (N-OAD) and it’s working principle, structure design and flow regime were studied. The fluid domain model of N-OAD was build and the phase distribution of oil and air two-phase flow on distribution interface was simulated based on the CFD model in Fluent. Meanwhile, the bubbles were found in the lubricant during the experiment, so, the void fraction and viscosity properties of bubbles oil was tested by image processing method and the Mars40 rheometer, respectively. The results showed that the viscosity of the lubricating oil was increased by the mixing of bubbles and the key factors of bubble oil formation are air pressure and oil feeding.

Engines are very important power units in aircraft and automobiles. After running for a period of time, carbon deposit formed on the surface of the engines, which will increase energy consumption, reduce the performance of the engines, and pollute the environment. Therefore, it is important to understand the morphology and chemical composition of carbon deposit to avoid the formation of carbon deposit. In this paper, the surface morphology and elemental composition of carbon deposit were studied by scanning electron microscope and energy dispersive X-ray spectrometer. In addition, the chemical groups of carbon deposit were explored by thermogravimetric and Fourier transform infrared spectroscopy. The results show that the carbon deposit originates from fuel oil and lubricating oil and their additives, engine matrix, and air. Carbon deposit is composed of organic components, inorganic components. The organic components include saturated hydrocarbons, unsaturated olefins, alcohols, phenols, aldehydes, ketones, acids, and esters.

In view of defects such as shrinkage cavity and looseness in ingot, ProCAST was used to conduct multi-level simulation of casting temperature and casting speed of 50Kg P20 ingot during casting, and analyzed the quality of ingot under different casting schemes, and finally obtained the relatively optimal casting scheme. For the ingot type used in this study, the influence degree of shrinkage cavity and porosity can be effectively reduced when the selected pouring temperature is 1570 ℃ and filling time is 20 seconds. The research results provide some reference for the optimization of casting scheme in the actual production of small steel ingot.

Underwater manipulator plays an important role in underwater operation, and structural design is of great significance to the function and underwater operation of underwater manipulator. At present, the structural design lacks systematic summary. This paper attempts to illustrate the structure of underwater manipulator according to its carrier, operation and function, clarify the matters needing attention in the design of underwater manipulator, and provide summary experience for the design of underwater manipulator.

Due to the characteristics of space products such as long life, harsh and complex service environment, various metal materials used in space products are put forward strict requirements. The sample box of a low-temperature equipment will have "dew point" corrosion in the low-temperature -80℃ working environment, and the anti-corrosion performance of the material surface directly affects whether the sample box can serve in the harsh and complex environment for a long time. Through the selection of parts material, parts and components surface anti-corrosion treatment, enhance the anti-corrosion performance of components in low temperature environment. To explore the shear strength and peel strength of low-release one-component RTV and space-grade RTV at room temperature and -80℃, as the guiding parameters for the selection of anti-corrosion coating, and finally realize the sample box in the low-temperature -80℃ environment with high reliability and long life.

The Yi lacquerware pattern is abundant in content and exquisite in design. It has extremely strong regional characteristics and value connotations. Through field investigation, literature research and physical research, this study analyzes and extracts the pattern theme, morphological structure and typical color of Yi lacquerware from the perspective of design. We use morphological displacement method to redesign the extracted basic pattern and combine the arrangement rules to create a derivative pattern. We apply the derivative pattern to a modern women’s leather bag design, modeling production and simulation presentation through 3D digital software. Finally, we evaluate the design results through eye-movement experiments. The results show that the design method proposed in this research can produce leather bag products with ethnic characteristics while meeting the aesthetic perception of modern women. The cross-domain migration of Yi lacquerware patterns on leather bags can bring new artistic connotations and cultural meanings to contemporary leather products.

The copper anode shaping unit can improve the efficiency of copper electrolysis. The milling technology at the lug of copper anode plate is designed to a number of high-speed cutting difficulties. There is still a large gap between domestic units and imported units. Therefore, on the basis of the original design, the milling earphone part is transformed to make the milling earphone meet the control requirements of higher precision. Based on the box Behnken experimental design method, the response surface experiment is designed, the response surface model is established, and the processing parameters of milling earphone are optimized, which provides a theoretical reference for the parameter debugging of milling earphone of copper anode unit.

The surface quality of copper (Cu) microstructures restricts the improvement of their performance. In order to improve the surface quality of Cu microstructures, a subsequent polishing process is required for the microstructures. Electrochemical polishing (ECP) has great potential in high-quality surface polishing of metal structural parts. The viscous film is the key to the realization of the Cu ECP process. In this paper, a multiphysics coupled model is used to analyze the effect of the viscous film and its fluidity on the current density and material removal rate (MRR) at different positions of the microstructure. The simulation and experimental results show that the generation and flow of the viscous film during the ECP process leads to differences in the current density at different positions of the microstructure, thus causing differences in the MRR at different positions of the microstructure. The material removal of the microgroove with thicker viscous film was uneven and smaller. The ability of ECP to process the microgroove was improved by reducing the accumulation of viscous film in the microgroove. This study is not only instructive for the ECP process of microstructures, but also contributes to the further understanding of the ECP mechanism.

Biology has evolved over hundreds of millions of years to form excellent bionic objects that inspire the design of bionic robotic mechanical structures, and combing bionic structures and objects from an evolutionary perspective can make the design of mechanical mechanisms clear. Arthropods occupy 80% of the animal species, among which spiders, locusts, dragonflies, and butterflies with flying abilities are excellent bionic objects.

At present, China's furniture manufacturing enterprises are still in a backward stage in the application of production lines. Most of the production lines of enterprises are still manual, and workers have been engaged in a simple and repetitive work for a long time, which inevitably leads to the problem of unbalanced production lines. This paper takes the table furniture manufacturing enterprises as the research object, investigates the tableware manufacturing process, obtains the production line data, and uses the application program analysis, operation analysis, action analysis and other methods to analyze the current situation of the table production line. Then, using the "5W1H" questioning technique and the four principles of "ECRS", the action analysis and improvement of some stations on the table production line were carried out, and some stations were reasonably split and merged. The bits are decomposed and reorganized. After the improvement, the handling times of the dining table production line were reduced by 5 times, the time was saved by 96.45 seconds, the number of people was reduced by 4, and the distance was reduced by 21 meters. It can be seen that the balance improvement of the company's table production line is necessary and effective.

The use of steel slag to prepare cementitious materials has significant economic and environmental benefits. However, steel slag has shortcomings such as large fluctuation in composition, high content of free calcium oxide, and difficulty in stable control of product quality in industrial production, which seriously restricts the large-scale applications of steel slag in building materials industry. This study proposes to use electric arc furnace (EAF) slag as a component adjustment material to react with basic oxygen furnace (BOF) slag at high temperature, in order to optimize the composition and structure of BOF slag, thereby improving its cementitious activity. The results show that using EAF slag as a component adjustment material to remelt BOF slag at high temperature can improve the cementitious properties of BOF slag mortar samples at various curing ages. When the early cementitious properties are the main target, the optimal remelting conditions are: the remelting temperature is 1150 °C–1200 °C, and the dosage of EAF slag is 10%–15%.

Steel slag belongs to bulk industrial solid waste, and it is of great significance to carry out comprehensive application research of steel slag, which will help to realize the secondary resource and efficient utilization of steel slag. FeO and Fe₂O₃ in converter steel slag can be reduced to metallic iron in high temperature reducing atmosphere, which lays the foundation for optimizing the composition and structure of steel slag and improving the gelling activity of steel slag. In this paper, bituminous coal was used as reducing agent to carry out the reconstruction experiment of mineral composition of converter steel slag. The influence of bituminous coal content and reaction time on the cementitious activity of reconstructed steel slag was studied, and the mechanism of reduction and tempering was analyzed. The results show that the cementitious activity of the converter steel slag is significantly improved after reconstitution, and the 7 d, 28 d and 90 d activity indices of the mortar samples can reach 84%, 99% and 87%, respectively. Mineral composition analysis indicates that the reconstructed steel slag compositions are composed mainly of alite, belite, C₂F, C₆AF₂ and Fe₂O₃. After reconstruction, the formation of C₆AF₂ is found because of the combination of the aluminate phase and the ferrite phase at high temperature.

In order to realize the fast and accurate welding of automobile parts, a kind of automatic welding robot with simple structure, reliable performance and high control precision is designed in this paper, the selection and design of the main hardware in the control system are described in detail. The hardware part mainly includes the STC12C5A32AD single chip microcomputer as the control core, which uses the key input and the sensor to complete the system information collection, MCU control relay, solenoid valve on and off to achieve welding power, pneumatic components and other executive control. Liquid crystal display synchronous display machine running status.

In this paper, the surface coating (resin type) on the steel surface of highway auxiliary facilities was improved by adding nano-TiO₂, by combining pre-fabricated TiO₂ nanoparticles with binder (organic, inorganic or organic-inorganic hybrid binder) A new type of self-cleaning composite coating material with photocatalytic and hydrophilic properties was obtained, and the self-cleaning performance of the sample was studied. The experimental results show that the self-cleaning coating material obtained in this paper can catalyze and photolysis the oily pollutants attached to the coating surface.

This paper summarizes the current state of research on finned tube heat exchangers to provide guidance and reference for their heat transfer design as well as application. The different types of fin structures used to enhance heat transfer outside the tube are broadly classified as flat fins, corrugated fins, and slotted fins. This paper analyzes and summarizes the effects of different fin structure parameters such as fin pitch, fin length, fin thickness, number of tube rows, tube spacing, and pipe diameter on the heat transfer performance and flow friction performance of heat exchangers under different fins structures.

Fatigue fracture is the main failure mode of ship structures. The redistribution of welding residual stresses during crack propagation has a great influence on fatigue life. In this paper, the welding residual stress redistribution law of AH36 marine high strength steel under crack propagation condition is studied. The initial welding residual stress is calculated by the finite element method. The life-death element method is used to study the redistribution of welding residual stress under the given crack size, and the results are compared with the calculation results of the welding residual stress redistribution formula proposed by Terada to verify the feasibility of the finite element method. On this basis, the redistribution of welding residual stresses in the crack propagation along the weld direction was studied, and the influence of crack propagation with different shapes on the redistribution of welding residual stresses was further studied and the redistribution of transverse welding residual stresses during crack propagation was obtained. The calculation method can lay the foundation for the prediction of structural fatigue crack propagation considering the welding residual stress redistribution in subsequent studies.

Refrigerant is an essential working medium in air conditioners, and the use of environmentally friendly refrigerants can effectively solve the problem of global warming. However, when selecting a new refrigerant, a comprehensive assessment is required, and any substance should be assessed for its overall impact on the global environment, energy efficiency, cost-effectiveness and safety. In this paper, the research progress of experimental research and application of traditional nano-refrigerants and environment-friendly refrigerants is reviewed. The main purpose of this paper is to evaluate the potential of all refrigerants used in the refrigeration and air-conditioning industry and to introduce the main applications of environmentally friendly refrigerants. The paper also points out deficiencies in the literature and points out the direction of future research work.

With the explosion of manufacturing technology in recent years, the digital application of dental industry will become an inevitable trend of industry development. However, there is a serious shortage of digital denture designers and a lack of standardization of digital product design. Some people in the industry believe that the establishment of large-scale denture design center and centralized production have many advantages, such as standardizing software operation process, unifying product standard, reasonably allocating production resources and improving production efficiency. In this paper, through the large-scale production efficiency experiment of students and technicians, analysis of production data, and analysis of multiple factors, it is concluded that large-scale centralized production can indeed improve the efficiency of digital denture design.

With the further maturity of researchers' study on the power source that can be continuously produced such as solar energy, people are increasingly cared for about how to make practical instructions of these power that can be continuously generated. In recent years, with the development of nanotechnology, researchers have found that by combining nanoscale particles with basic phase change materials (PCM), the heat storage of solar energy can be greatly improved. In this paper, it is discovered that when graphite particles are added to pure change materials of state, the heat exchange rate can be greatly improved due to the high thermal conductivity and Brownian motion of graphite particles.

The existing nodular cast iron manhole cover has good toughness and corrosion resistance, thus prolonging the service life of the nodular cast iron manhole cover, but it is basically not equipped with anti-theft function, so the nodular cast iron manhole cover can be easily stolen by hook-like objects. In view of the above problems, this paper designs a rotary anti-theft manhole cover, which is mainly technically characterized in that the vertical rectangular shaft and the central groove rotate clockwise, so that the ends of the two toothed plates facing away from the gear slide out of the transverse cavity and are pressed into the clamping groove. The magnet has an adsorption effect on the toothed plates, and then the rotary anti-theft manhole cover is fixedly installed on the upper end face of the shaft, thus preventing thieves from stealing the manhole cover from the Jing Zuo through a hook object.

In recent years, with the rapid development of hypersonic aircraft, aircraft flight speed and time are greatly improved, so the aircraft equipment some components put forward higher temperature requirements, for the ground real simulation of local high temperature, this paper developed a high temperature environment simulation system based on graphite rod. Graphite heating rod is used as the core heating component, and water-cooled copper electrode, elastic support pad and graphite support frame form the heating unit; silicon control regulator, temperature controller and tungsten thermocouple form the measurement and control system; remote PC LabVIEW program serves as the control unit. The ultra-high temperature environment simulation system successfully heated the test component temperature to 1600℃ to verify the working performance of the product.

In view of the time-consuming and laborious problem of artificial tree planting in northwest China, this paper introduces an automatic tree planting machine specially used for planting drought-resistant saplings in desert ecological areas, aiming to alleviate the desertification problem in China, promote the ecological balance and economic development in China. First, this paper introduces the main functions and technical characteristics of the machine, and focuses on the design principle and manufacturing technology of the main mechanical structure of the tree-planting machine. Secondly, the design and analysis of the mechatronics principle and remote control mode of the tree planting machine, as well as the composition of the circuit modules such as single chip computer and Bluetooth, and the application of 5G Internet of Things technology in the tree planting machine is conceived. Then, according to the work situation of the prototype, the main technical parameters of the tree-planting machine are obtained. Finally, the future development direction of the tree planting machine is planned, and with the continuous improvement of the product, the ecological relationship between society and nature will be more harmonious, and the desertification problem can be solved.

This paper introduces a multi-functional online automatic calibration device composed of a circular grating encoder as the standard and a self-designed mechanical automatic and data automatic acquisition system. Through this device, the calibration of the inclinometer, the angle encoder and the polyhedral prism can be realized, and the calibration data acquisition process can be automated at the same time.

Given that the disassembly speed of the body of the telescopic belt conveyor operated in an underground coal mine couldn’t keep consistent with the advancing speed of the working face, a telescopic system specially for the belt conveyor was designed. Then a detailed comparison of the merits and demerits and a force analysis of different telescopic systems were made in this paper. Lastly, a conveyor belt-oriented friction-type traction device was invented for specific working conditions. And the traction device is characterized by strong adaptability and high working efficiency and could retract and extend the telescopic part continuously and automatically, which provided an effective technical solution to facilitate the intelligent and efficient development of the modern mine.

A new strategy for constructing visible-light-driven catalysts is to create NH₂-MIL-88B (Fe) / PDA / rGO composites by polydopamine bridge crosslinked graphene oxide and NH2-MIL-88B (Fe). In this paper, the charge transfer mechanism is proposed. This mechanism is involved in the photoinduced electron transfer to the electron trap of graphene oxide through PDA channels and holes captured by it so that the electron-hole pair is effectively separated and the charge recombination is inhibited, prolonging the lifetime of the photogenerated carriers. At the same time, this work also exposed more active phases of NH₂-MIL-88B (Fe) in go and PDA to promote the application of polydopamine bridging materials in photocatalysts with high energy visible light activity.

Firstly the structure of the microelectromechanical wireless power transmission system inside human body was introduced, the signal generator, inverter main circuit and drive circuit of the high frequency inverter were designed, A power generator with adjustable frequency was developed. Then the wireless power transmission system of the capsule endoscope was established, the lamp in the capsule endoscope was lit successfully. At the same time the frequency tracking experiment could maintain the resonance state of the system, which showed that the design is feasible and effective.

Different from other conventional large converter in Shougang, Shougang 100 t low flow bottom blow converter is easy increasing the phosphorus in the furnace before steel tapping, especially low carbon steel smelting. For this phenomenon, The effect of the presence of solid phosphorus-rich phase C₂S-C₃P on the phosphorus distribution ratio was investigated, test and calculation shows that solid phosphorus-rich phase in slag can improve the phosphorus distribution ratio. The reason is that the nature of the steel slag changed, it is mainly due to the reduction of the phosphorus-rich phase C₂S-C₃P in the slag, in addition, the change of iron water Si content in the converter has a certain impact on the phosphorus content at the converter end point, smelt the low phosphorus steel by double slag method, when the silicon content is below 0.40 % every 0.10 % reduction in Si content, the P content increase about 10 ppm. In addition, the oxygen supply is too high, it also easily leads the increasing of P at the end point , the main reason is FeO increasing and reduce C₂S-C₃P in furnace slag , This results in increased phosphorus in liquid slag, resulting in redistribution of P between slag and steel.

Control and management of the production schedule and capacity of the traditional sheet-metal and the its manufacturing industry is extensiveness due to the poor level of fine management of the sheet-metal workshop and the unsatisfied transmission of the data and information, which effect the improvement and the high-quality development of the sheet-metal workshop/enterprise. To meet the development of the modern sheet-metal workshop, a discrete digital sheet-metal workshop is constructed based on the workshop layout with shortest logistics route. The discrete digital sheet-metal workshop processes the digital management based on the manufacturing execution system, digital programming based on model, and numerical control machining based on parametric process library, which has important demonstration effect and guiding signification to the further construction of the new type sheet-metal workshop and the transformation and upgrading of the traditional sheet-metal workshop.

In this paper, a kind of disk curve is constructed and different approaches to degree reduction are discussed. Firstly, to enhance the flexibility of Ball curve, a generalized Ball curve with two shape parameters is defined based on the cubic λμ-Ball basic functions and recursive properties. Then, based on the disk arithmetic, the disk λμ-Ball curve is obtained and some properties are studied. Furthermore, the particle swarm optimization algorithm is used to accomplish the optimization model of degree reduction, which is established by measuring the distance between the two disk curves through L₂-norm. Results show that PSO algorithm is an effective tool for degree reduction with different shape parameters.

As the uses of long chain fluorocarbon (hept-) producing highly toxic by-product for the environment, people have to develop new material that have ‘durable water repellent’ characteristics, and do not contain fluorine in its molecules as well as achieving hydro-phobicity, oleo-phobicity, ice-phobicity and stain resistance simultaneity. In this review, we will discuss the chemistry and physical properties of hydrophobic materials for instance discussion on Cassie-Baxter and Wenzel state; manufacturing desired textiles introduces electrospinning and polyphenol chemistry; improving durability of textiles coating. And we will also discuss the future challenges for the treatments and possible uses of textiles in industry.

Urban Road surface using sprinkler or spray dust, a certain water pressure washing way to clean operations, control the degree of air pollution, increase the humidity of the air. Now the city machine sweep, sprinkler rate reached more than 95%, although the benefits of sprinkler operation, due to the sprinkler body is too long, weight block, throttle water pressure is not easy to control, water supply difficulties and other reasons, the operation of the citizens will inevitably cause some inconvenience, and water waste is too large. Therefore, we designed a new road spray dust removal device, using the form of hydration spray instead of the traditional sprinkler mode, the ability to absorb dust in the air is stronger, to achieve a more efficient dust removal effect. The device uses natural resources such as sunlight, noise and rainwater to generate electricity, and the rainwater can be reused when it flows into the storage chamber. In addition, air water technology is used to inhale ambient air and condense and collect water after purification. At the same time, it has electronic display screen to warn pedestrians when the device is spraying. This device adopts humanized design concept, energy saving and environmental protection.

Aiming at the design objective of high efficiency and low resistance, this paper firstly designs and selects the key components of the fresh air purifier; then establishes the physical mathematical model of the fresh air purification product and sets reasonable boundary conditions through the method of computational fluid dynamics, simulates and calculates the flow distribution, velocity field and pressure field in the flow channel under different air volumes and different structural layouts; optimizes the internal flow field through the structural optimization of the fresh air purifier to provide a design basis for the design of the fresh air purifier. The results show that the fresh air purifier meets the design requirements.

With the development of information technology, smart ships have become a major breakthrough for the shipbuilding industry to seize innovation advantages. Based on the needs of intelligent ship development in our country, the concept of intelligent design and operation and maintenance is proposed, the corresponding design ideas and functional framework are analyzed, and the key technologies that need to be broken through in the future are discussed.

The tropical marine environment is characterized by high temperature and high humidity, and the service life of electrical equipment will be greatly shortened under such high humidity. Traditional dehumidification technologies such as condensation dehumidification have low-efficiency issues; rotary dehumidification system takes up a lot of space and costs high; solid desiccant dehumidification system’s regeneration rate is slow and dehumidification efficiency is low. In the current trend of refrigerant researchers pursuing environmental friendliness and high energy efficiency, in this paper, the transcritical CO₂ (T-CO₂) compression refrigeration system is jointed with the liquid desiccant dehumidification circle, and the compressor’s exhaust heat is directed into the regenerator of the dehumidification system to regenerate the desiccant solution. According to experimental studies, this design improves the overall COP of the system from 2.61 (the CO₂ cycle alone) to 3.83 (the jointed system). This jointed system solves the mismatch of dehumidification & refrigeration load and inefficiency of condensing dehumidification in ordinary refrigeration systems, and effectively utilizes the high-grade exhaust heat of the T-CO₂ refrigeration system, solving the inefficiency of the T-CO₂ refrigeration cycle.

The collision dynamics of a flexible beam with a central rigid body for wide range motion is studied. The dynamic equations of the central rigid-flexible beam system before, during and after collision are established. Firstly, based on the rigid-flexible coupling dynamic theory of flexible multi-body system, the rigid-flexible coupling dynamic equation of the system without collision is established by using Hamilton minimum action principle, taking into account the transverse deformation of the flexible beam and its second-order coupling quantity. A collision dynamic solution method is proposed to solve the collision process by means of vibration mode analysis, impulse-momentum method and contact restraint method. Based on the analysis of the vibration mode function of the flexible beam, the coordinated initial collision conditions are obtained by using the impulse-momentum method to realize the motion transformation, and then the contact restraint method is used to solve the collision process, realizing the transformation and dynamic solution in three different stages. The research shows that the collision process solution method avoids the calculation inconvenience and error caused by setting contact parameters and can be easily used to calculate the collision problem of flexible multi-body system. Flexibility, large-range motion and impact effect of beam are coupled each other. Collision causes high-frequency vibration components of flexible beam in wide-range motion. The amplitude of elastic vibration increases greatly, which excites the intense conversion between system kinetic energy and potential energy. Collision behavior has a great influence on the collision process of flexible multi-body system and the global dynamic behavior after collision.

Design review is an important node of automotive design and development process. The progress and quality of the review will directly affecting the development cycle of vehicle. Traditionally, clay modeling and CAS methods are used in the automobile design, that have high cost of time. In recent years, with the rapid development of high and new technologies such as computer graphics and virtual reality technology, CAVE is gradually applied in automobile research and development. CAVE as a highly immersive virtual reality system, can provide diversified solutions for traditional modeling design review of auto companies. This paper firstly proposes a display structure based on a sealed mobile structure with surround view CAVE technology. Compared with traditional display devices, it has the characteristics of convenient movement, rapid arrangement and storage, etc. Then the paper introduces the design and implementation of the whole vehicle virtual review system scheme, which provides a new tool for the research and development of automobile enterprises, and also verifies the feasibility and effectiveness of using the virtual reality system to assist the research and development of vehicles.

Screw ship unloaders are commonly used in wharves around the world for their advantages in efficiency compared with other unloaders. However, the unattended screw ship unloader system is under an approximate blank state at home and abroad. This article claims an unattended scheme for screw continuous ship unloaders to improve the core competitiveness of coal-fired power plants. This article includes the unattended operation process of ship unloading and discusses key technologies used to solve technical problems. In a nutshell, the unattended scheme of screw continuous ship unloader reduces the training cost for screw ship unloader drivers and provides a solution in unattended ship unloading with higher safety levels and efficiency.

A production scheduling method based improved genetic algorithm is proposed to minimize the completion time of dismantling decommissioned power batteries. The crossover operator of the genetic algorithm is designed to increase the diversity of individuals in the offspring population, expand the population size during the iteration of the algorithm, improve the coverage of the population, and increase the convergence speed of the population by retaining the excellent chromosomes. The algorithm is tested by using arithmetic example. The results show that the proposed improved genetic algorithm significantly outperforms the standard simulated annealing algorithm and the traditional genetic algorithm.

Due to increasing demand for high-speed and large capacity of data transmission, seamless connection between space network and Internet becomes one of the current trends of space communication. Under this background, this paper proposes an IPv6 over AOS gateway system based on FPGA to integrate the Internet and the space network. The system achieves protocol conversion to transmit IPv6 packets through the packet service in the AOS spatial data link protocol, and also has the function of address resolution and label switching. The main contents of this paper are as follows: 1. The IPv6 protocol, NDP protocol, MPLS technology and the conversion mechanism of IP over AOS protocol are studied. 2. The system test environment was set up to simulate the datagram transmission of spatial link between different node, the system performance and link stability were carried out by using logic analyzer and network packet capture tools. 3. The results of the function verification and performance test were analyzed and summarized according to packet loss rate and bandwidth availability ratio. The system achieves a variety of data types and large capacity information data transmission, it can also reduce networking costs while improving the transmission efficiency.

It took PLC as the control center and Codesys software as the development platform to improve the the fire fighting robot’s obstacle avoidance performance. The ultrasonic sensors were used to detect the obstacles. Under complex fire environment, the obstacle avoidance function was realized simply and quickly, and the fire extinguishing operation was carried out efficiently, which greatly increased the applicability of fire-fighting robots in dangerous and complex environments, and reduced unnecessary national property losses and fire-fighting personnel casualties. By analyzing the obstacles encountered, it designed and optimized the hardware circuit and software program of the system, it could choose the best way to avoid obstacles and improve the obstacle avoidance performance.

In this paper, the defects of the current airfoil parameterization methods are analyzed, and a method using particle swarm optimization (PSO) algorithm to solve the Bernstein coefficients in the CST method is proposed. Then, the NACA0012 airfoil and RAE2822 airfoil are modeled by CST method, and the Bernstein coefficients are converted into design variables in THE PSO optimization algorithm for solving. The influences of Bernstein coefficients of different orders on the airfoil generation accuracy are compared, and the optimal Bernstein coefficients are finally solved.

Piezoelectric bimorphs as miniature missile rudder actuator components have the insufficient driving force, and difficult to satisfy the requirement of miniature missiles for steering gear drive. Aiming at this problem, finite element models of the piezoelectric bimorphs; Analyzes the static and dynamic characteristics of piezoelectric bimorphs; Explore the support way and the electrical connection in the way that affects the performance of the piezoelectric bimorphs output, with the method of superposition, increases the driving force of the dual piezoelectric bimorphs. The simulation results show that the finite element model of piezoelectric bimorphs can accurately describe the output performance of piezoelectric bimorphs and determine the electrical connection mode between cantilever support and parallel connection. Finite element model and the simulation results, and comparison of three layers of piezoelectric bimorphs stack driver can reach 2.7 times that of single piezoelectric bimorphs driver can get 2.5 N driving force, to satisfy the miniature missile claim to the actuator drives the driveability.

This paper aims to improve the satisfaction and user experience of consumer clothing customization based on the functional requirements and weights of consumers for the clothing customization platform. First, the user journey map is used to analyze the process of consumers in the clothing customization platform, and summarize the pain points and needs. Second, the Kano model is used to categorize and rank user needs. By translating user needs into methods to improve the platform development, corresponding methods are obtained, such as strengthening the application of 3D digital technology and upgrading the online design service system. Finally, the development of the consumer clothing customization platform optimization is designed by the user’s need, to provide references for the optimization of the clothing customization platform.

Welding technology is the foundation of structure forming process in mechanical industry, and welding seam tracking is the key technology of intelligent welding. The scholars current study of welding seam tracking has been a lot, but mostly involves complex visual identification, complicated control algorithm and multi-sensor data acquisition, brings to the system to deal with the heavy burden of data operation, and in practical production because of the different welding conditions, to have different demands, this paper in all kinds of welding conditions for classification principle. The advantages and disadvantages of various weld tracking methods are summarized, and the tracking methods with adaptability under various working conditions are put forward, which can be used for reference by readers of various research directions.

Currently the carrying rate of advanced driver-assistance system (henceforth called ADSA) in vehicles reached 30% and the utilization rate is increasing. For production vehicle, comfort and psychological acceptance of automatic driving system are important for user experience and the prevention of motion sickness. This paper presents a methodology and evaluation algorithm for control quality analysis of ADSA. Through the analysis of longitudinal acceleration and jerk in time domain and non-time domain, multi-dimensional results based on test scenario are obtained. Form the result, we can quantitatively analyse the bad working condition and calibration tendency of the system. The purpose of the paper is to (1) presents an evaluation method of intelligent driving comfort, (2) provide a data processing and evaluation algorithm for road test and simulation test, (3) carry out a real vehicle test to verify the algorithm and analysis the difference of productions by benchmarking test.

In order to improve the accuracy of subway tunnel settlement prediction, the role of long short-term memory network (LSTM network) in subway tunnel settlement prediction was studied. Reverse neural network (BP neural network), support vector machine (SVM) and LSTM network are used to build models, combined with the measured data of Shanghai subway tunnel, the prediction accuracy of the models is compared and analyzed. The test results show that LSTM network is better than BP neural network and support vector machine, and have high prediction accuracy. Compared with the BP neural network model and the support vector machine, the average prediction error of the LSTM network model is reduced by 72% and 75%, the average relative error is reduced by 72% and 75%, and the root mean square error value is reduced by 73% and 78%, the predicted results are closer to the actual measurement results. The research shows that the LSTM network, one of the deep learning methods, is introduced into the subway tunnel settlement monitoring, which improves the prediction accuracy.

In order to promote the industrialization of SLM process, this paper puts forward a new and efficient detection method, analyzes the defects in SLM process, and puts forward a nonlinear detection method for silk laying process in SLM process. Based on the Faster R CNN framework, the algorithm is optimized to increase the refinement and fusion of the deep information in the image, and a multi-scale feature fusion algorithm based on the original network is constructed. The algorithm model is trained, the performance is discussed, and the application suggestions are given.

Wearing safety helmets is important for the safety of power operators, and using computer vision technology to automatically identify whether operators wear safety helmets can improve the efficiency of safety management. However, due to complex background, illumination condition, this task is non-trivial. We propose in this a method based on YoloV3 network which can effectively solves the problem. We added bi-directional adaptive feature fusion module which is able to better exploit the discriminative power of the low-level features and high-level features. Experimental results have demonstrated the effectiveness of the proposed method.

This paper mainly analyzes the temperature curve of PCB circuit board in soldering furnace, through the knowledge of heat transfer and change the temperature of each area and conveyor belt speed to study the change of temperature curve. Through the analysis, it is concluded that the circuit board transfer process is mainly heat convection and heat radiation. The ordinary differential equations based on heat convection and heat radiation are established between each temperature region and its gap. According to the law of energy conservation and the time of circuit board temperature field entering back welding furnace, the initial conditions are obtained. The temperature distribution in the center of the welding area at different time was obtained by using the improved Euler method. The ergodic search algorithm is used to search in a certain range, and finally according to the temperature process boundary, a better initial velocity condition is obtained through calculation and analysis. Add the ideal furnace temperature curve and the temperature in the center of the welding zone should not exceed 217 for too long, and the peak temperature should not be too high to minimize the area covered by the ideal furnace temperature zone over 217 to the peak temperature. Covariance analysis was conducted on the two sets of data values by taking a certain amount of equidistant discrete points of the temperature on the left and right sides of the peak temperature, so that the furnace temperature curves with the peak temperature as the center line exceeding 217 were as symmetrical as possible.

Based on the data of "Calculation and Management Platform for Energy Efficiency Test Data of Industrial Boiler", the test situation of industrial boilers approved products of 2020 were analyzed, and the statistical results were compared with the energy efficiency indicators of TSG G0002—2010 statistically in this article. Finally, the industrial boiler product development trend in recent years were analyzed.

For complex product design, requirements-based verification is very important. This paper conducts a thorough investigation of the current requirements-based verification methods in the industry, and conducts research on the problem of unclear transfer paths from the problem domain to the realization domain of the requirements verification, and proposes the improvement of the ARVM method, introduces the product realization into the requirements verification, and realizes the project verifying products in different configurations and states at different stages.

Levelness of drilling platform is an important index to evaluate its performance. Based on angle sensor as measuring unit and single chip microcomputer as the control core, a four-legged drilling platform is constructed. A hydraulic automatic balancing system is designed by using the synchronous characteristics of hydraulic transmission and the way of unidirectional balancing and linkage of two legs. The practical application of engineering drilling-rig shows that the balancing system has good reliability, especially suitable for large tonnage drilling-rig.

For the flexible job shop scheduling problem with the objective of minimizing the maximum make-time, an adaptive discrete particle swarm algorithm is proposed. The algorithm adopts an initialization method that combines random generation and process-based global load minimum selection machine initialization. At the same time, in order to improve the convergence speed of the algorithm, an adaptive inertia weight is added to the particle position update method, and crossover and mutation operations are introduced. Through comparative experiments and numerical analysis of benchmark examples, the effectiveness of the proposed adaptive hybrid discrete particle swarm optimization algorithm is verified.

The welder in the existing industrial robot consists of a soldering iron, a welding rod and a welding nozzle fixed on the welding rod. The welding nozzle consists of a flat plate and a plurality of welding columns spaced at a certain distance on the flat plate, which can quickly weld or weld multiple welding spots on electronic components at the same time at one time. However, its defect is that the distance between multiple welding heads or welding columns is fixed, which leads to the small application range of the welding machine and can't meet people's needs. In order to solve the above problems, this paper presents an array intelligent solder industrial robot, whose main technical feature is that the motor drives the No.3 screw rod to rotate through the output end, and the distance between two solders can be adjusted according to the needs, thus improving the applicable scope of solder.

Robot welding workstation has been widely promoted and applied with the development of industrial robot, electronic control and welding equipment. Based on FD-B4L (OTC) robot and DM350 (OTC) welding machine, a robot welding workstation was designed, which can be used to weld sheet metal parts and vehicle-mounted cabinet. This paper introduces the welding fixture and the selection of main equipment and accessories in robot welding workstation in detail. The size and mechanical property of the cabinet welded by the robot welding workstation are checked, which meets the relevant requirements. The robot welding workstation has a high value of popularization and application.

The factory simulation plays an important role in factory design and the production line optimization. 3D modelling is a significant step of the factory simulation. Current modelling methods take many efforts to create a model which can barely be reused, so a 3D modelling system which is a module embedded in the factory simulation software was proposed. Based on the analysis of the model requirements in factory simulation, we combined ontology with variational design to describe a model, and the geometric implementation methods of the definitions in the ontology were given to produce a 3D model. In the end some models were created using the system to prove the design.

Battlefield emergency repair performance evaluation of armored vehicles is an important step and basis for the evaluation of equipment quality characteristics and battlefield survivability. The purpose of such evaluation is to verify the correctness and applicability of different performance indicators in battlefield emergency repair environment. The Analytic Hierarchy Process (AHP) is a method to quantify qualitative factors, which is widely used in the field of program selection. In order to compare the priority of different battlefield emergency repair performance indexes, AHP method is applied in the evaluation of battlefield emergency repair performance index weights in order to reduce the subjectivity of artificially determined weights and determine the evaluation index weights with scientific methods, providing a method reference for similar evaluation in the future.

Based on digital image correlation method (DIC), the shear stability of two configurations of composite stiffened plates was experimentally studied. The test results show that the buckling load and failure load of I-stiffened panels are 158.2 kN and 282.1 kN respectively, and the main failure models are the debonding of the truss skin interface and skin folding; the buckling load and failure load of M-stiffened panels are 181.9 kN and 292.3 kN respectively, and the main failure modes are consistent with that of T-stiffened panels. Then, a progressive damage failure model of stiffened panels was established to simulate the buckling and post-buckling behaviour. The results show that the buckling mode, buckling load, failure load and failure mode are consistent with the experimental results.

The existing manufacturability evaluation methods of key marine diesel engine components are not advanced enough, and they have low accuracy. In this paper, an intelligent evaluation method for manufacturability based on the MBD model is proposed. The contents and construction approaches of the evaluation data resource database are elaborated which provides data sources for the implementation of the evaluation method. The intelligent evaluation of the manufacturability of parts is performed from different angles. The structural process evaluation method based on the T-S fuzzy neural network intelligent decision-making model is verified by example; the feasibility and accuracy of the method are verified by example.

The study on seismic collapse-resistance of buildings needs viewing from multi-parameter and multi-level aspects due to the discrete and systematic characteristics. The damage evolution strides over multiple hierarchies, i.e. components hierarchy, storeys hierarchy and structures hierarchy, as there exist differences and association in evolution law and damage distribution between each level. Three 1/3-scaled reinforced concrete frame models with three-bay and three-story were tested under reversed loading. By defining “importance coefficients” for different structural members, a damage model was established based on component category and the quantitative deduction of structural collapse was accomplished subsequently. On this basis, corresponding seismic analysis of RC frames was carried out. Test results indicate that the structural damage was concentrated on the column bottoms and beam ends of the first floor. The beams had positive effect on slowing the damage growth at pre-loading stage, full development of plastic hinges at beam ends was beneficial to reduce the failure level.

Dynamic gate assignment process is a sequential decision process. The change of flights schedule will affect the flight gate allocation plan of flights in the same time period and subsequent periods. The use of airport gates is based on complex business logic rules. When writing flight gate allocation algorithms, business rules need to be transformed into parameterized mathematical models, in which a large number of parameters such as weights and thresholds need to be set by employees based on their subjective experience. The feasible solution of the model based on subjective empirical parameters is different from the actual decision of operators. As a result, the outputs obtained by the optimization algorithm cannot meet the actual needs of operators. In order to complete the dynamic assignment of gates in a sequential decision mode that close to the manual operation strategy of flight delay recovery, this paper takes single flight gate assignment as the assignment strategy and adopts a trust region policy optimization algorithm based on attention network to solve the problem, which is aimed at reducing the blindness of subjective setting of priority parameters in the algorithm and the complexity of the artificial adjustment parameters, so that the allocation results of the optimization algorithm can be more practical.

Aiming at improving the poor effect of data ontology semantic information query, based on the existing semantic retrieval and combined with natural semantic processing technology, a data ontology semantic information query method based on natural semantic understanding is proposed. The natural semantic pattern is used to define the corresponding data ontology extraction rules, and the synonyms of domain ontology are obtained from relevant data. Further, Jena reasoning is used, and the implicit knowledge is obtained by combining domain knowledge and custom reasoning rules. Based on the natural semantics, a word similarity algorithm is proposed to analyze the syntax and semantics of the natural semantic query input by users, and construct SPARQL query sentences to realize the natural semantic query. The accuracy deviation formula is proposed to measure the rationality of the sorting algorithm, which simplifies the semantic information query steps of the data ontology. Experiments show that this method can obtain semantic information and effectively improve the accuracy of semantic information of data ontology.

Taking the application of intelligent recommendation in the military field as the research object, an intelligence recommendation model based on UML is established. Firstly, the characteristics and modeling process of UML are briefly introduced; Then, the working principle of the intelligent recommendation system for military intelligence and the workflow of recommending intelligence are explained; Finally, using UML tools to establish visual models of the system and its information flow from the perspectives of functional requirements, requirements analysis, system behavior, such as use case diagrams, class diagrams, state diagrams, activity diagrams, sequence diagrams and collaboration diagrams, which builds a bridge of undifferentiated communication between designers, developers, and intelligence users, and provides a scientific and feasible method for the design, construction and optimization of intelligent recommendation system.

In the process of our daily use of electricity, power load forecasting is very important. Short-term power load forecasting can effectively manage electric energy. In order to improve the intelligence of power grid, this paper studies the analysis and prediction methods of power load based on deep learning. Short-term power load forecasting can accurately predict the load and electricity consumption of a certain area, and provide reference for the operation of the power system. In daily life, our power load data are interfered by many factors, so we need to fully find out the temporal characteristics of power load data, so as to improve the accuracy of our power load forecasting. In this paper, a convolutional neural network-long-term and short-term memory neural network (CNN-LSTM) neural network prediction model based on convolution neural network and long-term and short-term memory neural network is proposed. The data characteristics are extracted by convolutional neural network (CNN), and then the accurate prediction of power load is completed by using the unique memory and prediction ability of long-term and short-term memory neural network (LSTM) neural network. The experimental results show that compared with the single LSTM neural.

Aiming at the problems of long search time and easy to fall into deadlock when using the traditional ant colony algorithm in the path planning process of UAV in two-dimensional space, this paper first introduces the advantages and disadvantages of the traditional algorithm, and puts forward an improved ant colony algorithm. Select A*, potential field method, traditional heuristic search strategy and obstacle avoidance heuristic search, improve pheromone update algorithm, and dynamically modify the dependence of transition probability on pheromone. The simulation results show that the improved ant colony algorithm has better global search ability, the path superiority is more prominent, the number of iterations and calculation time are optimized, and the stability of path search is greatly improved.

In the process of intelligent munitions attacking military objects, fast and accurate object detection is the key to the success of combat missions. There is a contradiction between the requirement of fast detection and the limitation of power consumption in deploying object detection algorithms on intelligent munitions. To meet the operational requirements of high altitude intelligent missile, the HiSilicon Hi3559AV100 chip with low power consumption and small volume is used as the carrier. By pruning the model and optimizing the small object detection strategy in large images, the detection accuracy of small objects in large images is improved by 30 %, and the real-time detection speed fps is increased by about 10 frames.