Research On Line-of-sight Stabilization Of Electro-opticalstabilized Platform

The electro-optical stabilized platform is a device that can effectively isolate the disturbance from the carrier and maintain the line-of-sight of the photoelectric load.Its main function is to obtain a stable image of a specific target outside the carrier.With a higher performance requirement of the electro-optical stabilized platform in military and civilian occasions,the study of line-of-sight stabilization technology is increasingly important.In order to improve the stability accuracy of the two-frame electro-optical stabilized platform,a control system based on dual-speed loop control has been proposed and a speed controller based on active disturbance rejection control has been introduced for the compl exity of disturbance factors.To inhibit the influence of micromechanical gyroscope noise on the line-of-sight,the gyroscope signal denoising method based on Kalman filter has been studied.The basis of design in the electro-optical stabilized platform is to analyze the mechanism of line-of-sight.In this paper,the kinematic relationship of each frame of electro-optical stabilized platform and the various disturbances which affect the line-of-sight have been studied,which provide the basis for the design of the electro-optical stabilized platform and the study of line-of-sight control algorithm.The servo control system is the key of the electro-optical stabilized platform.In this paper,the servo control system has been modeled while its characteristics are analyzed by frequency domain method.The analysis of the disturbance shows that the traditional single-speed loop control system has limited ability to inhibit the disturbance.In this paper,the control structure of the electro-optical stabilized platform based on dual-speed loop control has been studied,and the inhibition of moment disturbance and rate disturbance has been realized respectively.The active disturbance rejection control algorithm has been introduced,and the active disturbance rejection control stabilization controller has been designed for the servo control system,which effectively inhibit the complex disturbance factors.In the electro-optical stabilized platform,the noise of the gyro signal is one of the main sources of disturbance,and the noise reduces the stability accuracy of the line-of-sight.To inhibit the noise in the gyro signal,a method to analyze the noise characteristics by Allan’s variance estimation has been proposed.the gyroscope signal denoising method based on Kalman filter has been studied,which solves the problem of complex calculation of some denoising methods in embedded control system.Experimental results show the method can inhibit the noise of the gyroscope effectively.Optoelectronic stability platform system involves multidisciplinary technology.In this paper,the servo system of two-frame optoelectronic stability platform has been designed,and the control strategy has been verified.The experimental results show that the electro-optical stabilized platform designed in this paper has the ability of isolation rate disturbance and moment disturbance,and achieves the requirement of stability precision and servo stiffness.