Research On Motion Planning And Control Of A Spherical Robot

Spherical Robot is a new-style and intelligent robot, whose special motion fashion makes it not care of overturn and be able to get better stability. The spherical robot to be researched has a stable platform and can move in all directions. In this paper, the motion planning and control of the robot is detailedly studied.Firstly, the development of the spherical robot is introduced and according to the knowledge of the research forepassed, the nonholonomy and the nonlinear controllability for a spherical robot based on the principle of angular momentum conservation are discussed with the differential geometric control theory.A motion planning method with piecewise constant controls based on the differential geometric control theory is improved and optimized for the spherical robot and is applied into the obstacle avoidance. At first, according to the affine nonlinear control system without drift, the continuous sinusoidal controls are used to substitute the 26 segments of constant controls and to implement the motion planning of the spherical robot. Then, considering the special structure of the robot, an optimized tri-segment motion planning strategy is presented, which combined the cursory adjustment of the robot's position and the accurate adjustment of the configuration. Finally, the method is applied to the obstacle avoidance in the known environment with obstacles. The simulation results of the examples illustrate the effectiveness of the methods.Based on the control sequences from the motion planning, the motion control of the spherical robot can be realized. Both the software and the hardware system are designed in the paper. The ARM-core processor LPC2210 of PHILIPS is used in the hardware design; the software of the robot is designed combining with the RTOSμC/OS-II and the monitor system software is designed using LabVIEW. Finally, the motor rotating speed control of the spherical robot is studied with PID control whose parameters are adjusted by fuzzy control. The software of the fuzzy PID parameters self-adjustment system is accomplished with the corresponding simulation results.