Event-based Process Controller Design

Event-based control is a new control strategy.Compared with traditional periodical sampling control strategies,events determine the time instant of signal transmissions.Event-based control system can reduce the frequency of signal transmissions between the modules of control system without deteriorating the control performance through designing suitable event-triggered condition.This paper designs event-based control system for several low-order linear processes and the corresponding analysis and simulation experiments are done.The main contents are as followed:(1)Event-based control system for first-order linear stable processes is designed.An event-triggered mechanism which combines symmetric send-on-delta(SSOD)event-triggered mechanism and send-on-area(SOA)event-triggered mechanism is proposed.The controller structure composed with a PI controller and a P controller is adopted and the stability of the double event-based control system is analyzed.Then the processes with time delays are considered,by adding smith predictor in double event-triggered mechanism to eliminate the impact of time delays.Simulation experiments reveal that the control performance of the event-based control system designed is much better than SSOD event-based control system.(2)Event-based control system for first-order linear unstable processes is designed.Send-on-delta or time(SODT)event-triggered mechanism is proposed basing on send-on-delta(SOD)event-triggered mechanism.PI controller is used and the stability analysis is performed.Then the processes with time delays are considered with the double feedback loop control structure.The stability analysis is performed and the tuning method based on performance function is proposed.Simulation experiments verifies the feasibility of SODT event-triggered mechanism and reveal the superiority of SODT event-triggered mechanism.(3)Finally,event-based control for second-order linear processes is studied.The event-triggered mechanisms proposed for first-order linear processes are applied to the second-order linear processes by selecting the appropriate controller.Simulation experiments show that the event-triggered mechanism designed in this paper can be extented to event based control of higher order linear processes.