欠驱动水下机器人三维轨迹跟踪有限时间预设性能控制

Finite-time prescribed performance control for the three-dimension trajectory tracking of underactuated autonomous underwater vehicles

本文研究了具有不确定动态和未知时变海洋环境扰动的欠驱动水下机器人(AUVs)三维轨迹跟踪有限时间预设性能控制问题,提出新型预设性能函数和误差映射函数,将受预设性能限制的轨迹跟踪误差转变为非受限的变换后误差;构造新的超螺旋(ST)扩张状态观测器,在有限时间内实时估计AUV不确定动态和未知时变海洋环境扰动引起的总扰动;基于上述,设计新的ST控制律,实现了欠驱动AUV三维轨迹跟踪有限时间预设性能控制.理论分析证明了最终的AUV三维轨迹跟踪闭环控制系统的稳定性,仿真及仿真比较结果验证了所设计控制律的有效性和优越性.

In this paper, the finite-time prescribed performance control problem is investigated for the three-dimension(3 D) trajectory tracking of underactuated autonomous underwater vehicles(AUVs) with uncertain dynamics and unknown time-varying ocean environment disturbances. A novel prescribed performance function and an error mapping function are proposed to transform the trajectory tracking errors constrained by the prescribed performance into the unconstrained transformed errors. A new super-twisting(ST) extended state observer is constructed to online estimate the total disturbances lumped by the uncertain dynamics of AUVs and unknown time-varying ocean environment disturbances in a finite time.On the basis of the above, a new ST control law is designed to achieve the 3 D trajectory tracking of underactuated AUVs with the prescribed performance in a finite time. Theoretical analyses prove the stability of the resulting AUV 3 D trajectory tracking closed-loop control system. The simulation and the simulation comparison results verify the effectiveness and the superiority of the designed control law.