利用PWM对直流电机进行换向和调速，本程序同时控制四个电机。(Commutation and speed regulation of DC motor by using PWM)

对四电机移动机器人进行全向移动控制，并包含升降平台等，机械手抓的控制。(The omnidirectional movement control of the four motor mobile robot is carried out, including the lifting platform and the control of the mechanical hand grasping)