Correlation-based tuning of a restricted-complexity controller for an active suspension system,” European journal of control

A correlation-based controller tuning method is proposed for the “Design and optimization of restricted-complexity controllers ” benchmark problem. The approach originally proposed for model following is applied to solve the distur-bance rejection problem. The idea is to tune the controller parameters such that the closed-loop output be uncorre-lated with the measured disturbance. Since perfect decor-relation between the closed-loop output and the distur-bance is not attainable with a restricted-complexity con-troller, the cross-correlation of these two signals is mini-mized. This is done iteratively using stochastic approxi-mation. A frequency analysis of the tuning criterion al-lows dealing with control specifications expressed in terms of constraints on the sensitivity functions. Application to the active suspension system of the Automatic Labora-tory of Grenoble (LAG) provides a 2nd-order controller that meets the control specifications to a large extent