Research On Identification Of Chemical Process

This paper firstly introduces the summary about the basic principle and method of identification. Then discusses several effective identification methods in view of the closed-loop system, and has conducted the simulation research, includes following several aspects specifically.Firstly, identification experiment is discussed. In many papers about identification, estimating algorithms are concerned more attention than experiment design of identification. If experiment design is unreasonable, then the result of identification is not reliable. If the concept of identification is just founded on a group of algorithms or simply form of " data in , model out ", the result of identification will always be fallaciously. Discussing some problem such as selection of the input and output, sampling frequency, testing signal and pretreatment of data in detail, tabling a proposal of methods of collecting necessary information for characteristic of process .Introducing some algorithms of identification for open-loop system in brief, then introducing identification method for closed-loop system . Illuminating its characteristic by simulation instance, and indicating its shortcoming of this method in practical applications .Finally , this paper introduce an asymptotic identification approach based on NLJ method. The modified method has advantages of both methods, it can improve accuracy of NLJ method without the special signal of asymptotic method. It can obtain the exactly model without disturbance of the process and has been proved by industry application.