考虑避障的船舶轨迹跟踪滑模控制策略

Modeling of Trajectory Tracking Sliding Mode Control of a Vessel Considering Obstacle Avoidance

以某散货船为研究对象,设计一种基于滑模控制的轨迹跟踪控制策略。利用欠驱动船舶的运动特性建立误差模型,基于误差模型采用Lyapunov直接法设计虚拟控制量,结合反步思想和积分滑模控制方法,分别对纵向速度及艏向角进行积分滑模面的设计,从而得到纵向推力及转艏力矩滑模控制律。针对环境存在障碍物等情况,采用人工势场法对轨迹进行调整以有效避免船舶在运动过程中发生碰撞。仿真结果表明,所设计的轨迹跟踪控制策略可以有效跟踪期望轨迹并在运动过程中实现避障。

A trajectory tracking control strategy based on sliding mode control was designed for a bulk carrier. The error model was estab1 ished by the motion characteristics of underactuated ship,and the virtual control variable was designed by Lyapunov direct method based on the error model. Combined with backstepping method and integral sliding mode control method,the integral sliding mode surface was designed for surge velocity and yaw angle respectively. Therefore,the surge force and yaw torque sliding control law were designed. In view of the obstacles in the environment,the artificial potential field method was used to adjust the trajectory to effectively avoid the collision of ships in the process of movement. Simulation results showed that the proposed trajectory tracking control method could effectively track the desired trajectory and avoid obstacles in the process of motion.