基于改进Super-Twisting滑模与干扰观测器AUV控制方法

An AUV Control Method Based on Modified Super-Twisting Sliding Mode and Disturbance Observer

摘要:

以X 舵智能水下机器人(Autonomous Underwater Vehicle，AUV)为研究对象，提出了一种改进 Super-Twisting 滑模与非线性干扰观测器结合的 AUV 控制方法。首先，对 AUV 进行了运动学、动力学以及 X 舵分配进行了建模；之后，按照 Super-Twisting 理论设计了 AUV 控制器；然后，考虑到原算法中符号函数引起的控制输出抖振现象，提出了基于 Sigmoid 函数的改进 Super-Twisting 控制器，考虑到未建模动态以及外部环境干扰，设计了非线性干扰观测器对集总干扰进行补偿；最后，通过仿真验证了所提控制器的有效性。仿真表明，在干扰影响条件下，所提方法能够在大幅降低输出抖振并保证良好的控制精度。

Abstract:

This paper proposes a new control method for X-rudder AUVs based on the combination of modified Super-Twisting sliding mode and disturbance observer. First，the kinematic model，dynamic model and force allocation model are provided. Then，an AUV controller is built based on Super-Twisting theory. Moreover，to decrease the chattering effects caused by the signal function in the controller，a modified Super-Twisting controller is designed based on the sigmoid function，and a nonlinear disturbance observer is given to compensate the influences of current disturbances and uncertainties in models. Finally，simulations are carried out to illustrate the effectiveness of the proposed method. The results show that chattering effects are largely fixed and the tracking errors are converged to zero under the influences of current disturbances and model uncertainties.