基于相关分析法的PID控制回路模型验证

Model Validation of PID Control Loop Based on Correlation Analysis

介绍PID控制回路的性能指标及评估方法,并针对控制性能不佳时无法判断是由过程模型失配还是扰动模型失配所致这一问题,提出了一种模型验证方法。通过引入一个准白噪声序列,对实际输出序列和噪声序列使用相关分析法进行分析,并将结果与性能良好时的过程模型脉冲形式进行对比,以确定控制回路性能不佳的原因。通过仿真实例验证了方法的有效性。

Most of the control loops applied in the process industry are of PID type.Even in the advanced control system,control performance is greatly affected by the status of PID control loops in the basic level.So,performance assessment of PID control loops has become extraordinarily important.PID control loop performance index and assessment methods are introduced.Then a model validation method is proposed to identify the possible reason of the poor control performance： whether it is due to the process model mismatch or the disturbance model mismatch.Through the introduction of a quasi-white noise sequence into the control loop,a correlation function can be evaluated,which is further compared with the result of the pulse sequence,and then the reason for poor control loop performance can be identified.Simulations have been made to verify the effectiveness of the proposed method.