复合干扰下载人潜水器的全阶滑模控制

Full-order sliding-mode control of manned submersible in the presence of lumped disturbances

针对蛟龙号载人潜水器(JIAOLONG)在运行过程中受到深海洋流、模型不确定性和未建模动态等因素影响,本文设计了一种基于干扰观测器的新型全阶滑模控制(disturbance-observer based full-order sliding mode control,DOB–FOSMC)方法.首先,建立载人潜水器系统的动力学模型;然后,设计扩展非线性干扰观测器估计系统的复合扰动;其次,设计能够描述潜水器完整动态特性的全阶滑模面,从而得到滑模控制律,并给出闭环控制系统的稳定性分析;最后,通过数值仿真验证控制方法的有效性和优越性.基于干扰观测器的全阶滑模控制方法的优越性主要体现在:能够描绘载人潜水器的全阶动态特性,并且有效抑制抖振现象.

In this paper, a novel disturbance-observer based full-order sliding mode control (DOB--FOSMC) method is proposed for the JIAOLONG manned submersible in the presence of external disturbances, model uncertainties, and un-modeled dynamics. First of all, a six-degree-of-freedoms (DOFs) dynamic model of the manned submersible system is presented. Then, an extended nonlinear disturbance observer is employed to estimate the lumped disturbances. In addition, a full-order sliding mode surface that is able to illustrate the full dynamics of the manned submersible is designed. And the sliding mode control law is developed for the manned submersible system. Furthermore, the stability analysis of the closed-loop system is given based on the Lyapunov theory. Finally, some comparative simulation results are presented to demonstrate the effectiveness and superiority of the proposed DOB--FOSMC method for manned submersible system. This novel DOB--FOSMC method has two key advantages: its capabilities to illustrate the full dynamics of systems and to suppress the chattering phenomenon.