A Motion Control Study Of The Omnidirectional Mobile Robot

The omni-directional mobile robots (ODMR) are special wheeled mobile robot. Theycan move to the arbitrary directional in zero-radius of gyration and move efficiently in thecrowded and narrow environments. The omni-directional wheels are the core unit of ODMRand the key to omni-directional motion of robots. The purpose of this thesis is to research thestructure design and motion control of the ODMR.The robot equipped with the MY wheels is studied and the optimizing process of thestructure is analyzed. Strength of the3D model of the MY wheel with MY3of4-cone withPU is validated for the carrying capacity. The kinematics model and dynamics model of threeand four wheels ODMR are built. Based on the kinematics model and dynamics model, thevelocity and the acceleration are analyzed in the certain maximum velocity and maximumacceleration of with three and four wheels when ODMR move to the arbitrary direction of theplane. According to those analyses, the movement characteristics of the maximum velocitydirection and maximum acceleration direction of the ODMR with three wheels is the differentand the four ODMR is the same.Base on the direction diversity of the maximum velocity and maximum acceleration onthe ODMR with three wheels. With avoidance of the movement slip of wheel in the motion,,the trajectory planning in the movement between two points in the plane. Base on two kindsof the normal accelerated way, two kinds of the new accelerated method were proposed.Those are no-rotation and rotation accelerated method. To simulate the robot movement intwo kinds of the new accelerated method, the no-rotation accelerated method cost less timethan rotation method. But it has the deflection of linearity and is used to obstacle avoidance ofthe robot. When there is the rule of obstacles in the plane, the robot can use the newno-rotation accelerated method, snakelike Curve and sinusoid cure to avoid the obstacle. Thesimulation has showed that the no-rotation accelerated way cost less time and drive-energythan the others in the avoidance motion process.Kinematics model analysis of the ODMR and motion control plays an extremely important role in robot control and practical application.