基于变速趋近律的机电伺服系统自适应滑模控制

针对带有摩擦力矩、负载力矩以及扰动力矩等不确定性的机电伺服系统,提出一种基于变速趋近律的自适应滑模控制方法.首先,构造双曲正切型辅助函数并设计新的变速趋近律,用以调节滑模变量的收敛速度,使其在到达减速点之前具有较快的收敛速度,而在到达减速点以后则能有效削弱抖振.在此基础上,构造自适应滑模控制器,保证系统位置输出能够快速...

Adaptive sliding mode control of electromechanical servo system based on variable rate reaching law

This paper proposed a variable rate reaching law-based adaptive sliding mode control scheme for electromechanical servo systems with lumped uncertainties including friction torque, load torque and disturbance torque, etc. Firstly, a hyperbolic tangent auxiliary function is presented to construct a novel variable rate reaching law, which can adjust the convergence rate of the sliding mode variable. With the proposed reaching law, a faster convergence rate is achieved before reaching the deceleration point, and the chattering issue can be reduced after the deceleration point. Then, an adaptive sliding mode controller is designed to guarantee that the system position output can track the desired trajectory quickly and stably. Meanwhile, parameter updating laws are developed to estimate the upper bound of the square of the uncertainties, and thus the continuity of the control signal and the reduction of the chattering are both guaranteed. The error convergence performance of the proposed scheme is analyzed through the Lyapunov stability synthesis, and comparative simulation results are given to validate the effectiveness of the proposed scheme.