关键词: 光电稳定平台, 滑模变结构控制, 稳定精度, 摩擦适应, 伺服转台

Abstract: The photoelectric tracking system is subject to disturbances in the moving process of carrier, which has a negative impact on the tracking performance of the system. Sliding mode control has good robustness and can beeasily implemented, so it can be considered in such systems. Using friction feedback and combining sliding mode control for velocity loop with PID control for tracking loop, a sliding mode variable structure control strategy applicable to photoelectric tracking system is proposed. It improves the stability and accuracy of the photoelectric stabilization platform, and at the same time, it has certain robustness, which enables the running system to have certain adaptability to the changing disturbances when the external environment changes. The sliding mode controller is designed for the two-dimensional servo turntable, and then simulated and compared with the available PID-based control scheme.The comparative test results show that under given disturbances, the stability error of velocity loop of the photoelectric stabilization platform based on the sliding mode control strategy is reduced from 72″/s (arc-seconds per second) to 12″/s, and the root mean square is reduced from 37.0″/s to 1.46″/s. The effect of the proposed sliding mode controller on improving the stability and accuracy of the photoelectric stabilization platform has been verified.

Key words: photoelectricstabilizedplatform, slidingmodevariablestructurecontrol, stabilityaccuracy, frictionadaptation, servoturntable