本程序主要是对小车进行左转控制，有三种方法左轮抱死，右轮抱死，或者左轮后退右轮前进，三种方式进行左转-This procedure is mainly to control the car on the left, there are three ways, revolver, holding in death of the wheel lock, right or left back right wheel to go forward, three ways to turn left