An approach to vibration control by stereo vision system in mobile manipulator

A mobile manipulator is composed of the vehicle and manipulator part to expand the workspace area. In case of the rough terrain, however, the tip motion of the mobile manipulator oscillates. To obtain the stable motion by the manipulator, it is necessary to suppress the oscillation. To address the above issue, this paper describes a novel strategy to estimate the oscillation of the mobile manipulator by the stereo camera mounted on the vehicle. To recognize the oscillation of the mobile manipulator, a landmark point fixed in the workspace coordinate is utilized. Then the landmark point is detected by the stereo camera. From the motion of the landmark points on the image plane of the camera, the motion of the mobile manipulator can be estimated. Here, to describe the vibration of the mobile manipulator which occurs by the unevenness of road surface, the oscillation model composed of rotational and translational joints is introduced. Furthermore a motion planning of the end-effector is described. Simulation results are shown to confirm the effectiveness of the proposed approach.