基于改进Super-Twisting滑模与干扰观测器的X舵AUV控制方法

A Modified Super-Twisting Control Method with the Disturbance Observer for X Rudder AUVs

摘要:

本文以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 modified Super-Twisting control method with a nonlinear disturbance observer for an X-rudder AUV. First, the kinematic model, dynamic model and force allocation model are provided; then，the controller for the AUV is build based on Super-Twisting theory. Moreover, to decrease the chattering effects due to 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.