The Theroy And Appliction Of Robust Control And Internal Model Control

In this paper, three fundamental issues of robust control are discussed, which are model uncertainty description, nominal performance, robust stability and robust performance. There are two ways by which model uncertainty is described, they are norm-bounded uncertainty regions and general uncertainty regions. Consequently, two methods are discussed in this paper to deal with robust stability and robust performance.The methods are deeply discussed in getting model uncertainty .Four methods are applied and analyzed. Robust control is used to construct a IMC controller. The detailed procedure is: establishing the uncertainty region of the model. designing a controller which ensure the nominal performance. tuning the filter time constant to yield a IMC controller which guarantee robust stability and robust performance.This method is applied to three-parameter uncertainty first order process with dead time(FOPDT) .It is also applied to four parameter uncertainty second order process with dead time(SOPDT).Internal model control-based PID (IMC-PID) controller and its application is researched for FOPDT and SOPDT(second order process with dead time). Detailed IMC-PID controllers which have filter time constant as their only tuning parameter for processes mentioned above is acquired. Tuning results of such controller are put forward as well.A automatic tuning IMC-PID controller application software is improved in this paper .