Research On Control And Scheduling In Networked Control System

In recent years,networked control systems have gradually become a research hotspot in the field of communication and control.Since the networked control system is a combination of the control system and the communication network,many new problems have arisen,such as networked transmission congestion,packet loss and disorder,and many technical difficulties caused by the combination of the two.The traditional control theory is unable to adapt the comprehensive requirements of control quality and networked service quality under the networked environment,it faces enormous challenges.At present,establishing an effective strategy that can adapt to the networked control system has become the primary task of the research.This thesis takes the networked scheduling strategy analysis as the entry point.Through the establishment of multi-loop networked control system,the control and scheduling collaborative design method is studied in detail,and the limited communication resources in the system are optimally configured to improve the control performance of the networked control system and the networked service quality.The main research contents of this thesis are as follows:(1)This thesis details the basic problems faced by the networked control system,introduces the basic concepts of networked control system scheduling,and classifies the basic scheduling methods.Through the simulation experiments of several dynamic and static scheduling methods,the characteristics and differences of dynamic and static scheduling strategies are analyzed.(2)Considering that the global performance of the networked control system is affected by the two-way control and networked,this thesis uses the control and scheduling collaborative design method to optimize the performance of the networked control system globally,and the simulation proves that the key point of the collaborative design is the dynamic change of the sampling period.In this thesis,a variable sampling period scheduler is designed on the feedback channel,and the sampling period of different loops is dynamically adjusted in real time.The simulation experiment and comparison with the fixed sampling period scheduling strategy are carried out,and the effectiveness of the variable sampling period scheduling method is verified.(3)Considering the actual engineering application,there are often interfering nodes in the system,and the interfering nodes also have corresponding functions such as transmission or management data,and occupy a certain amount of networked bandwidth resources.Based on the design of the variable sampling period scheduler,this thesis saves the transmission traffic of networked data and reduces the networked congestion and packet collisions by setting the transmission dead zone at the same time in the bidirectional channel and implementing the two-way implementation of two new dead zone scheduling strategies.The problem is to indirectly improve the overall performance of the networked control system.In this thesis,the output response curve and IAE(Integrated Absolute Error)are analyzed and compared by multiple simulation experiments,which verifies the superiority of the collaborative design of dead zone scheduling and variable sampling period.