水下运载器非奇异快速终端滑模控制

针对传统基于线性滑模面的滑模控制方法收敛速度慢、易于颤振的难题,提出一种新型多变量非奇异快速终端滑模控制方法. 利用Lyapunov稳定性理论对该方法进行理论分析，结果表明：系统位置跟踪误差和速度跟踪误差将在有限时间内收敛到小球域内, 并且小于相同参数条件下传统基于线性滑模面的滑模控制方法. 以正在开发的北极星号遥控水下运载器的四自由度控制为研究对象, 将该方法和基于指数趋近律的传统滑模控制方法进行仿真对比, 结果表明：当存在较强未知外干扰和较大参数不确定性以及测量噪声时, 该方法相对传统滑模控制方法可以获得更快的动态响应速度、更高的稳态控制精度和更平滑的控制输入．

Nonsingular fast terminal sliding mode control for underwater vehicles

To resolve the problems in the traditional linear hyperplane-based sliding mode control (SMC) method such as low convergence speed and easy to chattering, a novel multivariable nonsingular fast terminal sliding mode control (NFTSMC) method was proposed. Theoretical analysis using Lyapunov stability theory was addressed for the proposed method. The result shows that the position and velocity tracking errors will converge to small ball fields in finite time, and they are smaller than the ones obtained by the traditional linear hyperplane-based SMC method under the same control parameters. For the 4-DOF (degrees of freedom) control of POLARIS remotely operated vehicle (ROV) which is being built up, comparative simulations were performed using the new proposed method and a traditional exponential reaching law based SMC method respectively. The results prove that the new proposed method can achieve faster dynamic response speed, higher steady control precision and more smooth control inputs compared with the traditional SMC method in the presence of large unknown external disturbances, big parameter uncertainties and measurement noise．