新型终端滑模在光电稳定平台中的应用

Application of new terminal sliding mode in photoelectric stabilized platform

为了提高光电伺服稳定平台的跟踪精度,针对系统中干扰的影响提出一种新型终端滑模控制算法。首先,提出一种新型终端滑模干扰观测器的设计方法,实现对系统中干扰的快速估计和实时补偿。其次,设计新型终端滑模控制器来提高系统的跟踪精度,结合有限时间收敛和自适应控制的思想,对切换增益进行在线调整,有效地抑制了滑模控制中的抖振问题,使系统状态能够在有限时间内快速地收敛到所设计的滑模面上,并对未估计干扰进行精细化补偿。最后利用Lyapunov理论证明控制系统的稳定性。实验结果表明:该控制策略保证了光电跟踪系统视轴对运动目标的跟踪精度,在0.05 Hz时误差小于0.002°,在2 Hz时误差小于0.034°,增强了系统的鲁棒性。

In order to improve the tracking precision of the photoelectric servo stabilized platform, a new terminal sliding mode control algorithm was proposed to solve the influence of the disturbance. Firstly, a new terminal sliding mode disturbance observer was constructed to realize fast estimation and real-time compensation for interference in the system. Secondly, combining the idea of finite time convergence with adaptive control theory, a new terminal sliding mode controller was designed to improve the tracking accuracy of the system, adjust the switching gain online, and reduce the chattering of the sliding mode controller effectively, so that the system state was quickly converged to the designed sliding surface in the limited time, and take fine compensation for non-estimated interference. Finally, the stability of the closed-loop control system was proved by Lyapunov theory. The experimental results indicated that this control strategy can ensure the tracking accuracy of photoelectric tracking system for moving targets. The error of tracking is less than 0.002°at the 0.05 Hz and less than 0.034°at 2 Hz, and the robustness of the system is enhanced.