Dynamics and Control of a Self-Reconfiguring Sphere Leading to the Design of a Spherical Mobile Robot

点击翻译按钮获取中文摘要

This research project deals with the design and development of a unique spherical mobile robot having a spherical exo- skeleton, an internal mechanism for self-propulsion, and a variety of sensors for motion control and reconnaissance. Unique Features of the robotic system include its retractable camera, retractable manipulators, and telescopic limbs. The arms and limbs are deployed for manipulation and support when the robot is at rest and retracted before the robot resumes its motion. The robot is able to perform rapid maneuvers and move over rough terrain with relative ease. In the process of development of the spherical robotic system, three fundamental problems in the areas of dynamics, control, and design of mechanical systems are addressed. The first problem relates to the development of a nonlinear feedback control strategy for nonholonimic systems with primary application to the rolling sphere. A smooth and time- invariant controller will be developed for the reconfiguration of the sphere. Despite significant progress in nonholonomic control systems, the reconfiguration of the rolling sphere is still an open problem. The second problem of this research is to design an internal mechanism for self- propulsion of the sphere and to construct a closed loop controller for the effective operation of the mechanism. The mechanism provides the sphere with the capability to accelerate, move with constant velocity, or servo at a point. The final problem relates to the development of the spherical mobile robot, which is expected to achieve autonomy thorough coordination between sensing and control. This problem deals with design of the truss, choice and placement of sensors, and design f the overall control system through integration of the two controllers mentioned above. The nonholonomic control strategy, developed as a part of this research, is incorporated in the Advanced Control Systems course, offered in the Department of Mechanical Engineering at Michigan State University. The internal mechanism for self-propulsion of the sphere and the design of the spherical mobile robot are used as motivational examples in a number of graduate and undergraduate courses in design, structures, mechanics, and controls.