Research On Performance Limit Of Networked Time-delay Systems Under Incomplete Information

Human society has entered the information network era and networked systems have emerged with the rapid development of information technology.Compared with traditional control system,the networked system can realize remote control by connecting the sensors,actuators and controllers in the communication network according to the rules.At the same time,networked systems are widely used in intelligent transportation,smart grid,mechanical automation,drones,telemedicine and other fields due to the advantages of fast transmission speed,easy control,and easy maintenance.However,in practical applications,there are many new problems in networked systems,such as transmission delay,noise,data packet loss,quantization,interference and a series of problems.These problems are caused by the intervention of communication networks and network bandwidth limitations,it will cause incomplete information transmission and thus affect the performance of the system.Most of the real systems are time-delay systems,and time-delay is a key factor affecting the performance of control systems.Therefore,it is more practical to study the performance of networked time-delay systems under incomplete information.This paper mainly studies the performance limit of networked time-delay systems under the constraints of parameters such as packet loss,noise,bandwidth,quantization,and encoding and decoding.Performance expressions for networked delay system.Considering networked time-delay systems affected packet loss,white Gaussian noise and bandwidth in the feedback channel,the performance limit of a single-input single-output networked time-delay system is studied.Using the spectral decomposition method,it can be seen that the performance limit of the networked time-delay system is affected by the unstable poles of the given object,the nonminimum phase zeros,the Gaussian white noise of the channel,the loss of data packets,and the bandwidth.Considering that there are factors such as quantization and encoding/decoding packet loss in the feedback channel,the performance limit of single-input multipleoutput networked time-delay systems is studied.Through partial decomposition and spectral decomposition methods,the display expression of the tracking performance limit of the networked time-delay system is obtained.The research results prove that in addition to the characteristics of the object that affect the performance limit of the system,codec,noise and quantization errors also affect the performance of networked time-delay systems.Considering the dual-channel noise and bandwidth constraints in the communication channel,the performance limitation of a single-input single-output networked time-delay system is studied.By using the Youla parameterization method and a two-degree-of-freedom compensator,the expression for the tracking performance limit is obtained.The research results prove that the characteristics of the object(non-minimum phase zeros,unstable poles)and the characteristics of the reference signal determine the performance of the networked time-delay system.In addition,bandwidth limitations and noise constraints also affect the performance limitations of the system to some extent.