位置和艏向角约束的非对角欠驱动USV轨迹跟踪

Trajectory tracking of non-diagonal unmanned underactuated surface vessel with position and yaw angle constraints

仅配备有纵向推进力和转船力矩装置的无人水面艇是典型的欠驱动系统,不能通过定常光滑反馈控制律镇定到平衡状态。本文针对一类惯性矩阵和阻尼矩阵非对角的欠驱动无人水面艇,设计了基于附加控制器和反步法的光滑时变跟踪控制律,在保证跟踪误差暂态性能的前提下,实现了曲线和直线情形下的轨迹跟踪。首先,通过状态变换将非对角模型转化为对角形式,并运用反馈线性化理论简化控制输入。其次,通过设计虚拟控制函数来镇定误差运动学方程,并通过引入障碍Lyapunov函数(BLF)来保证跟踪误差满足规定的性能。然后,通过在误差镇定函数中引入虚拟控制量解决了系统的欠驱动问题,稳定性分析表明本文控制策略能够保证闭环系统中的所有状态是一致最终有界的。最后,Matlab/Simulink仿真结果表明了该控制器的有效性。

Unmanned Surface Vessels(USV)with only surge force and yaw moment available are typical under actuated system which cannot be stabilized by any time-invariant continuous state feedback control law.For the realistic underactuated USV,where the mass and damping matrices are not diagonal,based on additional controller and backstepping method,a smooth time-varying tracking controller is developed to track any straight and curved reference trajectories,and also confines the transient response performance within the allowable range.Firstly,the system is converted into a diagonal form by using state transformations and control input is simplified through feedback linearization theory.Secondly,the virtual controller is designed to stabilize tracking error,meanwhile,Barrier-Lyapunov Function(BLF)is introduced to ensure that the tracking error does not exceed the prescribed value.Thirdly,the additional control is designed to deal with the problem of underactuation.Stability analysis shows that the proposed control strategies can guarantee all the states in the closed-loop system are uniform ultimate bound.Matlab/Simulink results illustrate the effectiveness of the proposed control design.