基于选择策略的移动机器人视觉伺服镇定方法

SELECTION-STRATEGY-BASED VISUAL SERVO REGULATION OF WHEELED MOBILE ROBOTS

针对单目视觉非完整移动机器人系统,提出了一种基于选择策略的视觉伺服镇定控制方法.具体而言,首先在视觉位姿估计的基础上,将相对位置及指向角度作为系统误差量,利用Lyapunov方法设计了视觉镇定控制律;然后,为解决该控制律在某些初始位置下导致机器人产生较大旋转角度的问题,文章对误差形式进行调整得到负向镇定控制律,进而对上述两种控制律制定相应的选择策略;同时结合主动视觉使目标特征处于摄像机的视野(field-of-view,FOV)内.仿真与实验结果表明,视觉镇定控制律能以相同控制参数在不同初始位姿下高效完成镇定任务,并且该选择控制策略可使云台旋转角处于合理的运动范围内.

For a monocular camera-based nonholonomic mobile robot system, we propose a selection-strategy-based visual servo regulation strategy. Firstly, based on the pose estimation by vision information, relative position and pointing angle errors are utilized to design the visual servo regulation controller by use of the Lyapunov techniques. Secondly, for the problem that this controller will generate large rotation angles when the robot at some initial positions, a negative regulation controller is given by changing the errors＇ form, then the selection strategy is designed for the above two controllers. At the same time, the active vision is combined to keeping the target in the camera＇s field of view. Simulation and experiment results show that the visual servo regulation controller can accomplish the regulation tasks efficiently by using the same controller parameters from different initial poses, and the selection strategy keeps the pan-unit＇s rotation angle in a reasonable range.