Research On Active Disturbance Rejection Control Technology Of Photoelectric Stabilized Platform Based On Disturbance Observer

The photoelectric stabilization platform is an advanced technology equipment which can eliminate the disturbance of the carrier and ensure the stability of the visual axis of the photoelectric detection equipment,so as to realize the real-time capture and tracking of the target outside the carrier.It will be affected by various disturbance factors in a variety of operating environments,which will reduce the visual axis stability accuracy of the platform.Therefore,it is of practical significance to study the control algorithm of photoelectric stabilization platform,improve its anti-disturbance ability and response speed,and improve its stability accuracy of visual axisIn this paper,a two-axis and two-frame photoelectric stabilization platform is selected as the research object,and the control algorithm is studied to improve the dynamic response characteristics and anti-disturbance capability of the platform system.The research work of this paper on the photoelectric stabilization platform is as follows:1.The structure composition and working mode of the photoelectric stabilization platform are analyzed,and the main disturbance factors affecting the stability of the viewing axis are studied.These disturbance factors are divided into model disturbance,torque disturbance,angular velocity disturbance and measurement noise.Based on the mechanism analysis of the control loop of the speed loop of the platform,the mathematical model of the optoelectronic stabilization platform is established with the method of system identification.2.The active disturbance rejection control algorithm of optoelectronic stabilized platform is studied.Aiming at the problem that the observation burden of linear extended state observer(LESO)will be increased if the model information is not used,an improved linear active disturbance rejection controller(MLADRC)based on the model information is proposed to improve the estimation accuracy of platform disturbance.The simulation and comparison experiments of MLADRC and LADRC platform control system are carried out.Through the simulation comparison,the adjustment time of MLADRC platform control system is reduced by 0.2s,and the disturbance inhibition ability of torque and angular velocity is increased by nearly 50%,but the inhibition ability of measurement noise is weakened.3.Aiming at the problem of MLADRC weakening the measurement noise suppression ability of the photoelectric stabilization platform,an improved velocity disturbance observer(VDOB)was proposed,and a comparative simulation experiment was conducted with the control system based on DOB platform.The simulation results show that the control system of VDOB platform has improved the measurement noise suppression by two orders of magnitude.Combined with the advantages of fast response speed of MLADRC and strong disturbance suppression ability of VDOB,an Active Disturbance Rejection Control(VDOBMLADRC)algorithm based on disturbance observer was proposed and applied to the speed loop of photoelectric stabilized platform.Finally,VDOB-MLADRC,MLADRC and LADRC platform control system simulation and comparison experiments are carried out.The simulation results verify that the control algorithm can not only improve the response speed of the platform system;And can further improve the disturbance suppression ability;Moreover,the platform system still has a strong robustness within the range of 20% gain variation of the platform model.