Journal of Control and Systems Engineering
Journal of Control and Systems Engineering(JCSE)

Virtual Reference Feedback Tuning Control Design for Closed Loop System
The problem of designing two-feedback controllers for an unknown plant is studied based on input-output measurements within a linear setting. The virtual reference feedback tuning control is a direct method that aims at minimizing a control cost of the 2-norm type by using a set of data about the plant. No model identification of the plant is needed. For the optimization problem in designing controllers, an iterative separable least-squares identification method is proposed by means of the separable principle. The identification method not only searches for the global optimum solution of the designed criterion with respect to the parameter vectors, but also reduces the possibility of convergence to a local minimum. When applied the virtual reference feedback tuning to a two-degrees of freedom control system, the extension of the filter expression used to reprocess the input-output measurement data is derived. Based on this filter , we can prove the equivalence between our virtual reference feedback tuning control and the model reference adaptive control Finally the simulation example results confirm the theoretical results.
Keywords:Virtual Reference Feedback Tuning; Nonlinear Least-Squares Method; Global Optimum
Author: Wang Jian-hong,Zhu Yong-hong


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