说明：  基于BP神经网络的二级倒立摆控制器选择小车的位移和速度及两个摆杆偏离铅锤线的角度和角速度为输入数据。并经训练可得到一个神经网络控制器。
(The controller of the double inverted pendulum based on the BP neural network chooses displacement and speed of the car, the angle between the two pendulums bar and vertical line and angle speed as the input date. A BP network controller can then be got by training.)