Abstract:
Objective Absorber is a very commonly used component in UAV OE platform, because it can effectively absorb the vibration caused by the UAV, thereby enabling the photoelectric platform to obtain more stable and clear image or video. In the recent years, many scholars focus their attention on many kinds of damper in order to further improve the imaging quality of the OE platform. Non-angular displacement damper is designed for optimizing the performance of platform payload, but its practicality is limited by large volume and heavy weight. So traditional damping absorber is still the most widely used damper in OE platform at present. A lot of research have been conducted about the characters of damping absorber, but quantitative analysis to address the impact of vibration on optoelectronic platforms and how to optimize the installation layout of OE platform with damping absorber has not been carried out.
Methods According to the characters of airborne OE payload, this paper analyzes and tests the angular characteristics of damping absorber that is related to the performance of airborne payload. First, the self-character of damper of EO payload is introduced. Second, the overall performance model of EO payload are established. Meanwhile, the modeling of motion characteristics is established and the factors that may affect the ability of airborne payload are analyzed during the installation layout of damping absorber. Many factors, such as stiffness, damping coefficient, installment-center-distance and the mass of payload, are promoted which determine the results of angular and linear displacement.
Results and Discussions The results of simulation analysis show that the displacement of damper mainly occurs in the vertical direction instead of horizontal direction, and the displacement in horizontal direction is only 2% in the vertical direction within the effective stroke of damper when the distance of rotation center R is set as 200 mm, 250 mm and 300 mm. The portable test system is mounted using a vibration table, an UAV OE platform with four damping absorbers and an auto-collimator. All the dampers, with the same stiffness and damping coefficient, are fixed between vibration table and UAV OE platform, and auto-collimator with target is used for testing the impact of vibration on payload imaging quality. Four images are captured by OE payload when the installment-center-distance is set as 350 mm, 300 mm, 200 mm and 100 mm respectively, and the vibration table is under 5 Hz low-frequency disturbances. It is not difficult to find that with the increase of installment-center-distance, the image quality decreases significantly. So, we should increase installation spacing of diagonal dampers as much as possible in application.
Conclusions According to the characters of OE payload, we researched the characteristics, motion modeling, and testing applications of UAV OE platform and its related damping absorber deeply. On the basis of introducing the working principles of damping absorber and OE platform, a motion characteristic model of the platform with damping absorber is established. At the same time, not only the theoretical model is simulated, but also the test results are conducted in laboratory. All the results indicate that the model can reflect the impact of damping absorber on the overall performance of UAV optoelectronic platform basically, and the results of our research in this paper are very helpful in optimizing the design, installation, and practical engineering applications of UAV platform.