Optimal Performance Analysis Of Communication Constrained Systems Based On Quantitation Constraints

With the development of computer and communication technology,network technology has been utilized to control system.However,due to the limitation of bandwidth,information will be adversely affected in the transmission process.Such control systems with communication constraints are called communication constrained systems.Compared with the traditional computer control system,the communication constrained systems has many advantages,such as resource sharing,remote operation control,simple wiring,convenient assembly,convenient diagnosis and maintenance,and so on.Therefore,communication constrained systems is widely used in management,production,life and other fields.However,due to the limitation of bandwidth,the performance stability of communication constrained systems will be adversely affected by network factors,such as,channel noise,network delay,packet dropouts and quantization and other factors.Therefore,it is of practical significance to study the performance of communication constrained systems.In this dissertation,the research mainly focuses on the optimal tracking performance(OTP)of communication constrained systems by considering quantization constraints.Based on the frequency domain analysis method,and combining the co-prime decomposition method,internal and external decomposition method,partial fraction decomposition method,norm theory and Youla parameterization method,the explicit expression of OTP of the communication constrained systems is obtained.The following researches have been conducted in this article.Considering control input power constraints,the OTP of the communication constrained systems with quantization constraints on the forward channel and packet dropouts and noise on the feedback channel is researched.The frequency domain method is used to analyze the OTP of the communication constrained system,and the explicit expression of the OTP is deduced by partial fraction decomposition and internal and external factorization.The results indicate that the OTP of the controlled object is only affected by the inherent characteristics of the controlled object(nonminimum phase zero and unstable poles)and network factors(quantization error,packet dropouts and noise).In addition,a simulation example is used to verify the theory.Considering the fading channel and quantization constraint on the feedback channel and the channel input power constraint,the OTP of the communication constrained systems is researched.The equivalent mean channel model is used to simplify the research process,and the explicit expression of the OTP of the communication constrained systems is derived by combining the frequency domain analysis method,the co-prime decomposition method and the partial fraction decomposition method.The results indicate that the OTP is affected by the nonminimum phase zero of the controlled object,the unstable pole and its direction,the quantization error and colored noise.In addition,a simulation example is used to verify the theory.Considering the delay,quantization and packet dropouts constraints on the feedback channel,as well as the two channel noise,and the channel input power constraints,the OTP of the communication constrained systems is researched.Based on the frequency domain method,an explicit expression of optimal tracking performance under the influence of quantization,packet dropouts,delay and two channel noise is derived.The results indicate that the non-minimum phase zero,unstable pole and its direction of the controlled object will affect the OTP of the system.It is further proved that the quantization error,packet dropouts,time delay and power spectral density of channel noise also have negative effects on the OTP of the system.In addition,a simulation example is used to verify the theory.