Nonholonomic-Wheel Mobile Robot (WMR)

An animation modeling a wheel mobile robot with two links manipulator. Run roboticprojectcase1.m or

When a person writes across a board, he/she positions his/her arm in a comfortable writing configuration by moving his/her body rather than reaching out the arm.The same situation happens in many case such as people transporting a heavy object cooperatively. Therefore, when a mobile manipulator performs a manipulation task, it is desirable to bring the manipulator into certain preferred configurations by appropriately planning the motion of the mobile platform.

If the trajectory of the manipulator end point in a fixed coordinate system(world coordinate system) is known a priori, then the motion of the mobile platform can be planned accordingly. If the motion of the manipulator end point is unknown a priori, e.g., driven by a visual sensor or guided by a human operator, the path planning has to be made locally and in real time rather than globally and off line.

This report presents a control algorithm for the platform in the latter case, which takes the measured joint displacement of the manipulator as the input for motion planning and controls the platform to bring the manipulator into a preferred operating region. By using this algorithm, the mobile platform will be able to ¡°understand the intention of its manipulator and respond accordingly.¡±

Since the mobile platform is subject to nonholonmic constraints, the control algorithm is developed using nonholonomic system theory.