带随机时延的异采样率双环网络控制系统仿真

Simulation of Dual loop Networked Control Systems with Different Sampling Rate and Random Time Delay

常规Smith预估方法对于带随机时延的网络控制系统不能取得满意的控制效果,多回路、多采样率的存在更增加了网络控制系统的复杂性。针对上述问题,提出了一种改进型的Smith预估器设计方法。以一类内外环采用不同采样率的双环网络控制系统为研究对象,通过添加辅助控制器,降低了系统对网络时延估计值的精度要求,从而减少了随机网络时延对系统控制性能的影响。仿真结果表明,在内外环采样率不同,并且网络时延随机变化、不能准确预估的情况下,改进方法比常规方法具有更好的控制性能。验证了改进方法的有效性和优越性。

Conventional Smith prediction method cannot achieve satisfactory control effect for networked control systems with random delay.The existence of multi-loop and multi-sampling rate increases the complexity of networked control systems.To solve these problems,we proposed a design method of the modified Smith predictor.A class of dual loop networked control systems with different sampling rate in inner and outer loops was taken as the study object.By adding auxiliary controller,the accuracy requirement of network delay estimation was reduced,which weakens the effect of random network delay on system control performance.The simulation results show that the improved method has better control performance than the conventional method when the sampling rates of inner and outer loop are different,and the network delay is randomly and cannot be accurately predicted.The effectiveness and superiority of the improved method are verified.