说明：  在工程应用中经常会遇到一些复杂的非线性系统, 这些系统状态方程复杂, 难以用数学方法准确建模。在这种情况下, 可以建立B P神经网络表达这些非线性系统。该方法把未知系统看成是一个黑箱, 首先用系统输入输出数据训练B P神经网络, 使网络能够表达该未知函数, 然后就可以用训练好的B P神经网络预测系统输出。
(In engineering applications often encounter a number of complex nonlinear systems, complex equation of state of these systems is difficult to accurately modeled using mathematical methods. In this case, BP neural network can be established express these nonlinear systems. The method of the unknown system as a black box, first with the system input and output data to train BP neural network so that the network can express the unknown function, then you can use the trained BP neural network prediction system output.)