When a feature point detection method is used in vision SLAM to match images, environment condition around the robot is uncertain usually. Many influence factors such as rotation, scale, fuzzy as well as illumination in the process of detection have a strong impact on robot's locating and incremental map building. Experiments proved that SIFT, SURF, BRISK, ORB and FREAK have good robustness under normal illumination. However, the illumination is complex in practical applications, and the stability of image features extraction will be affected. Based on a mobile robot vision platform, the speed, repetition rate and matching rate of five feature extraction algorithms above are compared and analyzed with different methods. Under dynamic illumination, the robustness and matching effect of image features with translation, rotation, scale and fuzzy transformations are also compared. Through experimental data analyzing, BRISK features shows better effect under dynamic illumination.
control method based on visual servo feedback is proposed, which is used to improve the attitude of a quad-rotor
aircraft and to enhance its flight stability. Ground target images are obtained by a visual platform fixed on aircraft. Scale
invariant feature transform (SIFT) algorism is used to extract image feature information. According to the image
characteristic analysis, fast motion estimation is completed and used as an input signal of PID flight control system to
realize real-time status adjustment in flight process. Imaging tests and simulation results show that the method proposed
acts good performance in terms of flight stability compensation and attitude adjustment. The response speed and control
precision meets the requirements of actual use, which is able to reduce or even eliminate the influence of environmental
disturbance. So the method proposed has certain research value to solve the problem of aircraft’s anti-disturbance.
For overcoming the problems such as remote operation and dangerous tasks, multi-terminal remote monitoring and warning system based on STC89C52 Micro Control Unit and wireless communication technique was proposed. The system with MCU as its core adopted multiple sets of sensor device to monitor environment parameters of different locations, such as temperature, humidity, smoke other harmful gas concentration. Data information collected was transmitted remotely by wireless transceiver module, and then multi-channel data parameter was processed and displayed through serial communication protocol between the module and PC. The results of system could be checked in the form of web pages within a local network which plays a wireless monitoring and warning role. In a remote operation, four-rotor micro air vehicle which fixed airborne data acquisition device was utilized as a middleware between collecting terminal and PC to increase monitoring scope. Whole test system has characteristics of simple construction, convenience, real time ability and high reliability, which could meet the requirements of actual use.
Applications of stroboscopic imaging technique in different areas are illuminated. Several major three-dimensional
morphology imaging detection methods for micro flexible adaptive aerodynamic shape, which are based on scaled model
in experiment process, are discussed at home and abroad at present. And stroboscopic imaging detection technique and
testing device are introduced emphatically, which could be used to obtain deformation information of flexible aerodynamic shape. A flexible aerodynamic shape detection method, based on the combination of stroboscopic imaging
technique and optical flow analysis, is proposed to validate experimental model for adaptive aerodynamic shape. This
technique could compensate the inadequacy of numerical analysis and provide more aeroelastic characteristics for
further analysis. Moreover, this measurement method is of advantages such as non contact, real time and visualization etc.
Research on LWIR multispectral imaging detection technology carried out in the key national defense laboratory in
Tianjin University is introduced in this paper. Firstly, a kind of infrared multispectral image simulation method based on
multispectral or hyperspectral images data in the VIS/NIR band is recommended. The combined strategy of
unsupervised and supervised classification methods is put forward to efficiently realize auto-matching and labeling of
pixels. Then, using the infrared image simulation technology, infrared multispectral simulation images can be generated
highly similar to real natural environments, which are valuable to the development of LWIR multispectral spectrometers,
as well as research on multispectral detection algorithms. Secondly, the co-image plane imaging detection technique is
presented as well as the attempt to make the small LWIR multispectral imaging detector based on such concept. A fourband
prototype has been achieved in VIS/NIR band, verifying the feasibility and validity of this technique.