说明：  基于BP神经网络的PID控制，利用神经网络的自学习、非线性和不依赖模型等特性实现PID参数的在线自整定，充分利用PID和神经网络的优点。
(BP neural network based PID control, self-learning neural network, nonlinear and non-dependent model and other characteristics to achieve PID parameters on-line self-tuning, full use of the advantages of PID and neural network.)