A MOVING BASE MOBILE ROBOT: KINEMATICS, STABILITY, AND TRAJECTORY CONTROL.

摘要

This study is concerned primarily with mobile robots that consist of an anthropomorphic arm and a maneuverable base. This model has at least one redundant degree of freedom to accommodate the movement of the robot base. In addition, the size and the weight of the base of the model are assumed comparable with its other links so that the dynamic stability problem must be taken into account.; The inverse kinematic problem of this robot model is analytically solved by a parameterization method. The reason for using parameters is that the robot model contains redundant degrees of freedom. The solutions are expressed in terms of the parameters chosen. With these solutions, much insight can be gained about the behavior of real systems.; The dynamic stability problem resulted from the robot mobility is considered. A set of sufficient conditions for maintaining the system upright configurations to avoid toppling over have been derived. The effects of this stability on the inverse kinematic solutions and the motion control problem are examined.; The main objective of this study is to incorporate the system dynamics, including the dynamic stability considerations, into trajectory control. A minimum time trajectory control problem, subject to a specified Cartesian path, dynamic stability, and robot actuator constraints has been solved. The solution takes advantage of the fact that once the path has been specified, the dynamics can be reduced to second order. This solution is implemented in the form of a computer algorithm. A redundant degree of freedom is also taken into account in the solution. Finally, the control scheme presented in this study allows the base of the robot to move while its hand and arm are performing tasks.