中文说明：
PSO算法的系统辨识，辨识一个锅炉蒸汽水位的传递函数。依据现有的数据，将传递函数辨识为2阶。
English Description：
The system identification of PSO algorithm is used to identify the transfer function of a boiler steam level. According to the existing data, the transfer function is identified as second order