Development Of Ground-based Operation Test Bench For Complex Optical Machine Functional Components

The ground-based operation test bench for complex optical machine functional components integrates multidisciplinary integration of mechanical structure design,kinematics,computer control,and so on.It can simulate the airborne environment under the condition of laboratory,and test complex optical-mechanical functional components,especially for an airborne aerial camera.The ground-based operation test bench can not only simulate the flight attitude and vibration environment,and has the functions of push-broom and whisk-broom with compensation for errors of IMC.As a kind of simulated motion device with special functions,the mechanical properties of the ground-based operation test bench will directly affect its dynamic characteristics.Therefore,it is very important to analyze the mechanical properties of the platform body during the design stage of the ground-based operation test bench.The main research contents of this dissertation are as follows:1)A kind of ground-based operation test bench with image shift error compensation was designed.By comparing the structure types of existing simulation platforms at home and abroad and the static and dynamic technical indexes required by the project,the overall structure of the ground-based operation test bench was designed.It was mainly composed of a flight simulation platform,a electromagnetic vibration table,and briefly described each component and function.The assembly methods of each shaft system and its components were described.At the same time,the main load calculation was carried out on the ground-based operation test bench,and and the model of the drive motor was comprehensively considered to determine the actual type of the drive motor to determine the overall configuration of the ground actual operation test bench.2)The static and dynamic mechanical characteristics of the main mechanical table were analyzed.In order to facilitate the finite element analysis of the machine table body,complex components such as drive motors,bearings,and shake tables were simplified and equivalently processed,and a finite element model was established.Through the static mechanical analysis of the ground-based operation test bench,the corresponding cloud diagrams of the overall deformation,stress and strain can be obtained,and the results shown that the stiffness and strength requirements were basically met;Through dynamic analysis,the natural frequencies and mode shapes of the first six modes were calculated,and the position of the weak stiffness of the ground pseudo-running test bench is analyzed.In order to avoid the resonance of the vibration environment frequency set by the vibration table,a modal analysis on the three-axis precision stable platform was performed to understand its frequency.3)The flight simulation platform is the key component of ground-based operation test bench.In order to obtain a reasonable control scheme,the dynamic coupling characteristics of the flight simulation platform were studied.The space rectangular coordinate system were established according to the frame structure,the dynamic equations of the flight simulation platform are derived through theoretical analysis,and the mathematical model of the control objects of the pitch frame and roll frame were established in conjunction with the simplified model of the torque motor.What's more,dynamic couplings of the frames were decoupled by the decouple theorem and inverse system method,and the equation of state was derived.4)The rotary accuracy of ground simulated operating test bed was tested.The shafting error of the ground actual operation test bench directly affects the angle measurement accuracy,an optical autocollimation method was used to measure the rotation accuracy of each axis in this paper.Analyzed the causes of errors and the NORMAT5000 dual-axis photoelectric autocollimator was used for the experimental detection,and the data was recorded and analyzed whether the obtained results meet the technical indicators required by the subject.