不确定非完整移动机器人的轨迹跟踪控制

具有未校准视觉参数的非完整移动机器人的运动学系统具有参数不确定性,较一般的运动学系统更加复杂.基于视觉反馈、Barbalat's定理和Lyapunov直接方法,研究了具有未标定摄像机参数的非完整移动机器人的轨迹跟踪问题.首先,利用固定在天花板上的针孔摄像机透视投影模型,提出了一种新的基于视觉伺服的移动机器人运动学跟踪误差模型；基于这个模型,提出了一种新的与未知视觉参数无关的动态反馈跟踪控制器.该控制器不仅保证系统的状态渐近跟踪给定参考轨迹,而且控制器是全局的,通过Lyapunov方法严格证明了闭环系统的稳定性.在惯性系和图像坐标系下讨论跟踪问题,使问题变的简单且设计的控制器更加有用.最后,仿真结果证实了所提出的控制器的有效性.

Trajectory Tracking Control for Uncertain Nonholonomic Mobile Robots

Nonholonomic kinematic systems with visual feedback are uncertain and more complex in comparison with common kinematic systems.The trajectory tracking control problem of nonholonomic mobile robots with uncertain camera parameters is addressed based on visual servoing feedback,Barbalat’s theorem and Lyapunov direct method.Firstly,based on the ceiling-mounted fixed pin-hole camera perspective projection model,a novel visual servoing kinematic tracking error model of a nonholonomic mobile robot is introduced.Based on this model,a dynamic feedback tracking controller is presented.Its tracking controller is independent of uncalibrated visual parameters by using new methods.The proposed controller not only ensures the entire state of the system asymptotically tracks the given trajectory,but also being global.The stability of the closed-loop system is rigorously proved by Lyapunov method.The most interesting feature of this paper is that the problem is discussed in the image frame and the inertial frame,which makes the problem easy and useful.Simulation results are provided to illustrate the performance of the control law.