Trajectory Planning and Dynamic Control of a Mobile Manipulator.

摘要

This paper presents methods of trajectory planning and dynamic control of a mobile manipulator. The proposed trajectory planning method consists of generating a trajectory for the platform from a given trajectory of the arm tip. The main concept of this trajectory planning method is to determine the redundant degrees of freedom of the mobile manipulator in order to minimize the value of performance index defined as a function of traveling distance, driving force, variation of joint velocity, and manipulability. Moreover, for tasks which require both control of the force exerted by the arm tip and control of the arm tip position, e. g., polishing, adding a function to the performance index to evaluate the direction of manipulating force enables generation of the trajectory on which the mobile manipulator has appropriate postures to exert a force on an object surface. Then, we describe a dynamic hybrid control method for the mobile manipulator, to control both the pushing force and the simultaneous positioning of the arm tip and the platform. This control method is based on the dynamic position control method which has already been proposed by [Y. Yamamoto and X. Yun, Proc. IEEE Int. Conf. on Robotics and Automation, 1994, 2187-2192]. Numerical examples and experimental results show the effectiveness of the proposed methods.