Design And Experimental Study Of Optical Pod Anti-vibration Isolation System

With the development of technology at domestic use of unmanned aerial vehicle(UAV),industrial unmanned aerial vehicle(UAV)has been more widely used in mapping,search and rescue,power line patrol,etc.As a main payload on the UAV,the optical pod has get more and more attention.The optical pod is mainly influenced by the vibration of the engine of unmanned aerial vehicle(UAV),the vibration of the unmanned aerial vehicle(UAV)velocity and posture changes,the impact of takeoff and landing include catapult launch and parachute.In order to reduce the vibration and improve the image quality of the optical pod,a small optical pod anti-vibration isolation system was designed.Vibration control can be divided into active control and passive control,although active control is effective active control is complicated.To design a small optical pod anti-vibration isolation system in the small unmanned aerial vehicle(UAV),the overall quality should be low,the structure should be not complicated and easy to accomplish,the cost should be affordable.So passive control was used to anti-vibration isolation system.Firstly,the unmanned aerial vehicle vibration environment test was carried out.And the vibration signal of cruise phase was recorded.With the help of the vibration signal processing,the frequency domain features and the time domain features were obtained in three directions.These experimental data provide significant reference for design of a small optical pod anti-vibration isolation system.Secondly,a multi-degree-of-freedom(DOF)system model of the optical pod anti-vibration isolation system was established,this vibration isolation system can configure the natural frequency effectively of optical pod isolation system.According to vibration theory,the spatial layout and relative positions,damping values and stiffness of isolators,and support structure was designed.What's more,the isolation system is decoupled and the basic parameters of the isolation system is determined through theoretical calculations.And a metal damper was adopted which has good performance and can withstand the impact of parachute.Thirdly,the dynamic model of the optical pod anti-vibration isolation system was established.And the modal information,coupling analysis,random vibration analysis and frequency response analysis was conducted by the simulation of Adams/Vibration module,the results show that the maximum error of the natural frequency calculated by theoretical calculations and simulation analysis is 1.27%.The finite element model of the optical pod anti-vibration isolation system was established.And the structure analysis and modal analysis were carried out by workbench to test the adaptability and reliability of the vibration isolation system.Finally,the optical pod anti-vibration isolation system is tested on a vibration table.The experiment results show that the transmittance is 0.2 in the vertical direction and 0.3 in the horizontal direction at 92.5Hz.And the error of natural frequency and the theoretical calculation is 2.81% in vertical direction and 10.5% in horizontal direction.The vibration isolation efficiency in the range of 0-250 Hz is 63.8% in the vertical direction and 55.5% in the horizontal direction.The field test image effects also prove the damping effectiveness of small optical pod anti-vibration isolation system.