The paper adopts the passive mechanical athermalization method to ensure the laser radar optical launching system works steadily and continuously in the temperature range of -10℃ to 50℃. Firstly, the weight ratio of the impact of temperature variations on the optical launching beam-expansion lens group is analyzed to carry out the athermalization design for the front multi-lens group. Next, the ZTC4 that matches the linear expansion coefficient of lens materials is selected based on analyzing and comparing the attributes of the lens barrel. Afterward, the redesigned elastic space ring is adopted to keep the spatial distance between each lens. Meanwhile, the distance is optimized and analyzed to construct the equation set for the size and axial direction of the elastic space ring and the stress variation. The equation set is later applied to making the rational design for the elastic space ring that achieves spatial localization. Meanwhile, optimal design parameters are selected for the elastic space ring to reduce contact stress and ensure axial consistency of the optomechanical system. Lastly, the flexible structural clamping ring is used for fastening. According to analytical results, the maximum axial displacement of the system is less than 0.06mm when the temperature of system changes; the surface accuracy of each lens is less than λ/8; the maximum stress of each lens is smaller than the yield strength of BK7 and SF8 glass lens material. All parameters meet the requirements on the athermalization design.
With the development of scientific technology, the requirement of aircraft level measurement technology is growing. The traditional measurement method and device have become the bottleneck of the production. The optical 3D large-size measurement technique, with the advantages of large measurement scale, high accuracy, high generality, high flexibility and automatic measurement, has becomes the primary technique for measuring the geometry of large-size object. For the actual problems existed in the routine the feature points of level measure technology, such as failure to meet required degree of accuracy, lower efficiency and slower speed of data processing, this paper puts forwards a new measuring scheme on the feature-points of aircraft level measure by using the optical measurement system of Laser radar. Initially, the measuring principle analysis has been performed based on the optical measurement system of Laser radar. The measurement scheme of the feature-points of level measure has been carried out on the basis of the principle. And then, it makes profound analysis of the key technology which includes the technology of CCD image alignment and station-moving measurement. After the actual detection, the combined error of each feature-point is less than the comprehensive error 0.3mm, meeting the measuring scheme of accuracy index. Analysis results demonstrate that design of the measuring scheme is effective, and can meet the requirements of actual applications.
This paper studied the 3-D reconstructing technology of free curved surface. Initially, it scanned the local model of
flight vehicle to use the new digital measuring equipment-laser tracker, got the point clouds of the model. And then, it
reconstructed curved surface of the model by using the powerful modeling function of CATIA. Finally, the paper also
utilized the units of alignment and data processing to make a relative error analysis of the reconstructed model and point
clouds. The experiment conclusion showed that the method of measurement accorded with error requirements, and had
the practical value of industrial application and production.
ARINC429 is the standard of digital transmission of avionic device. This paper used fault tree
analysis to diagnosis failures of aerocamera 429 communication, built up fault tree of aerocamera 429
communication, analyzed and diagnosed the failures, and designed the detecting flaw, finished aerocamera 429
communication detecting system finally. This detecting system can detect aerocamera 429 communication board
fast and effectively, and cut down period of clearing of fault. In addition, it can increase the direction of
maintenance and repair, improve the overall function of aerocamera.