Abstract: The traditional industrial vehicles and special purpose vehicles have disadvantages in aspect of steering, emission and noise, which on one hand results to inflexible operation and apparently does not conform to the subject of environment protection on the other. In order to overcome these shortcomings that vehicles can run in a small enclosed space as it is demanded and less environmental damege is caused, the improved control system of electric chassis featured by mecanum wheel is designed and developed. On the basis of earlier control system of the electric chassis, the kinematics models are analiced and simplified, closed-loop control system is designed based on fuzzy proportion intergration differentiation(PID)parameter distributor, and the hardware and software design is completed for control system. Two drive cycles are done to compare the new control system with the earlier control system, one drive cycle is a uniform linear motion which the speed νx=νy=0.35 m/s and angle speed z=0 °/s; another drive cycle is a uniform linear motion which the speed νx=νy=0.5 m/s and angle speed z=25 °/s; The experimental analysis suggested the improved closed-loop control system responded faster and had more accurate steady-state error in comparison of the motor encoder semi-closed loop feedback control system, which is more conductive to the promotion and application of this electric chassis.

Key words: Mecanum wheel;electric chassis;fuzzy proportion intergration dfferentiation