Equipment used to make the closed-loop control system reach the expected performance index or control target
Self tuning regulator (see system identification).The self-tuning regulator has the ability to estimate the parameters of the system or controller online, and can automatically modify the parameters accordingly by identifying the changes of the system and environment in real time, so thatClosed loop control systemAchieve the expected performance indicators or control objectives, and have certain adaptability.
Chinese name
Self-tuning regulator
Foreign name
self-tuning regutator
Utilization
Real time identification technology
Type
Adaptive control system for automatically correcting system characteristics
stayClassical control theoryAnd optimal control theory, the design method of controller is based onSystem mathematical modelBased on invariance or prior knowledge.However, the mathematical model of many actual systems cannot be accurately understood, and the system characteristics are changing with the change of environment.Therefore, the conventional nonadaptive control technology can not establish the mathematical model online, nor can it adjust the parameters of the system in real time.In order to overcome these shortcomings of common control technology,R. KalmanIn 1958, the idea of self-tuning regulator was proposed.However, adaptive control theory was not fully developed at that time, and there was a lack of applicable computers,kalman The idea of "has not been further developed, let alone put into practice.".In 1970,5. PetekaThe theoretical study of self-tuning regulator is extended to the random case.Then, withStochastic control theory、System identification theoryWith the development of computer technology, the research and application of self-tuning regulator has developed rapidly.1973K. J. AstramandB. WittenmarkA simple and feasible implementation scheme of self-tuning regulator is proposed, which has attracted wide attention.In this scheme, a linear difference equation (which can contain interference terms) representing the input-output relationship is used as the prediction mathematical model of the system (called controllableAutoregressive moving average model, abbreviated as CARMA), using recursionleast square methodThe parameters of the model are estimated online to directly obtain a self-tuning regulator with the minimum output variance (see Figure [self-tuning regulator]).The system in this scheme is simple in structure, easy to realize and easy to be popularized in industrial process control.Its disadvantage is thatNon minimum phase systemThe control process may diverge.In 1975,D. W. ClarkandP. J. GoslopThe self-tuning regulator scheme of generalized output minimum variance is also proposed, which can not only limit the amplitude of control input, but also limit the error between output and set value, and can be used for minimum phase system and non minimum phase system at the same time.1979 PE. Wellstead et al. proposed a self-tuning regulator with zero and pole assignment function, which can adjust the parameters of the system or controller online, so that the zero and pole of the closed-loop system can be assigned to the designated position.Then, for systems with different properties（Multivariable system、nonlinear system , distributed parameter system, time-varying system and continuous system).In addition, there are also some special self-tuning regulators, such as self-tuning LQG (linear quadratic Gauss) regulator, self-tuning PID (proportional integral differential) regulator, etc.
working principle
Announce
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In principle, the self-tuning regulator is based on the separation principle, which separates the parameter estimation and control law calculation.The recursive method is used for parameter estimation, which has less computation and is easy to be realized by computer.Self tuning regulators have been used in many engineering and technical fields (such as paper making, chemical industry, metallurgy, automatic pilot devices and manipulators for cement thermal ships and aircraft), and have achieved good results.
