Adaptive Exponential Time-varying Sliding Mode Control based on Disturbance Observer for Photoelectric Stabilized Airborne Platform

An adaptive exponential time-varying sliding mode control method based on a non-linear disturbance observer is proposed for a photoelectric stabilized airborne platform, taking aircraft torque fluctuations, nonlinear friction, and parameter uncertainty into consideration. The non-linear disturbance observer in the method is used to observe the composite uncertainty. The adaptive exponential time-varying sliding mode control module is integrated to realize global robust control of the angle rotation of the photoelectric stabilized platform impacted by residual disturbances not visible to the disturbance observer. The sliding mode controller is designed without the upper bound information of the composite uncertainty by the adaptive law. The exponential time-varying sliding mode function solves the problem of excessive adaptive for switch gain and improves the system response. According to Lyapunov's theory, the global asymptotically stable performance of the system is proved, and the angle position of system is asymptotically converged to the desired one. The simulation and prototype test results show that the method can achieve high-precision angle control despite external disturbances and parameter uncertainty. © 2022 China Ordnance Society. All rights reserved.