A direct tuning from input/output data of the Youla parameter in consideration of some deviated plants

Generalized Internal Model Control (GIMC) structure resolves the problem of trade-off between nominal control performance and robustness. In GIMC structure, while the nominal controller specifies the nominal performance, the Youla parameter improves robustness for uncertainties and/or disturbance rejection. This paper addresses the design method of Youla parameter on GIMC structure with stability constraint by the typical model-free controller design method, VRFT, to avoid complicated system identification and to design a fixed structural controller. However, the designed Youla parameter guarantees the closed-loop stability only at the specific condition where the input/output data is collected. If the load condition changes, the closed-loop stability is no longer guaranteed in the designed Youla parameter. In order to enhance the robustness for the plant perturbation and/or the plant uncertainties, this paper proposes the design method of Youla parameter in consideration of some deviated plants by VRFT. This method uses multiple input/output data sets collected from multiple deviated plants. The effectiveness of the design method is verified experimentally in a belt-driven two-mass system.