Research And Application Of Time-delay Control System Based On Smith-Fuzzy-PID Control Strategy

Time-lag phenomenon is widespread in oil refining,aerospace,machinery and other industrial areas.The process control in these industrial fields often has the characteristics of complex working conditions,changing parameters and control lag.The complex non-linear and time-lag process is challenging task in industrial control.Especially due to the existence of time-lag phenomena,the timeliness of disturbance monitoring is weak that making it difficult to select controller parameters.If the control parameters are not properly adjusted,then the quality of the system control will be degraded.In severe cases,the system will be unstable.Therefore,it is very important to study the control method of time-lag process in the field of industrial control and its application value.In this thesisr,the time lag phenomenon in industrial production process,the use of Matlab to build a temperature control system simulation model.According to the characteristics of the controlled object's lag,the control strategy of Smith predictive compensation and Fuzzy-PID hybrid control is selected:the system compensates for the lag phase by Smith predictor compensation;the system controller The Fuzzy-PID hybrid control strategy based on fuzzy rules is selected.When the system is in different fuzzy domains,the controller chooses different control modes:the fuzzy controller plays a major role in the phase of transient response and the PID control The controller plays a major role in this stage.At this time,the response of the system enters the steady state,and the error e and the rate of change of the error ec are very small.This control method takes into account the robustness of the fuzzy control,the short adjustment time and the high dynamic tracking quality And steady-state precision PID control and so on.And using the Smith-Fuzzy-PID hybrid control method to solve the fuzzy-PID switching controlleris easy to jump in the switching phenomenon.Through theoretical analysis and simulation analysis,The Smith-Fuzzy-PID compound control method proposed in this paper is better than the single one in the dynamic quality and steady-state accuracy of the system with time-lag links PID control or fuzzy control,with good control performance.In general,for high-order nonlinear,time-varying,and large-time-delaysystems such as central air conditioners,the control strategies designed in this paper have good control effects and dynamic characteristics,have certain self-adaptive capabilities,and can overcome the time-varying The influence of unfavorable factors such as time lag and delay on the system ensures the stable and efficient operation of the system.