De Bruyne, FrankyAnderson, BrianGevers, MichelLinard, N2015-12-130005-1098http://hdl.handle.net/1885/93942In this paper, we present gradient expressions for a closed-loop parametric identification scheme. The method is based on the minimization of a standard identification criterion and a parametrization that is tailored to the closed-loop configuration. It is shown that for both linear and nonlinear plants and controllers, the gradient signals can be computed exactly.Keywords: Closed loop control systems; Control system synthesis; Iterative methods; Linear control systems; Mathematical models; Nonlinear control systems; Parameter estimation; System stability; Gradient expressions; Nonlinear identification; Tailor made parametri199910.1016/S0005-1098(99)00108-92015-12-12