Iterative Feedback Tuning Applied to Robot Joint Controllers

: Tuning of robot joint controllers using iterative feedback tuning (IFT) is considered. Using a simulation model of a two-link robot arm the applicability of IFT is investigated for a nonlinear and multivariable system. Due to the strong crosscoupling between the two links a decoupling controller is needed in order to obtain satisfactory results. An approach for obtaining a decoupling controller is investigated. It is also shown how IFT can be used to tune the controller parameters for a particular trajectory of the arm. Keywords: Iterative methods, robotic manipulators, decoupling, multivariable, nonlinear. 1. INTRODUCTION Iterative feedback tuning (IFT), as initially proposed in Hjalmarsson et al. (1994a), is a method for tuning of the parameters in feedback control systems without needing an explicit model of the system to be controlled. In the IFT method one iteration in the tuning procedure corresponds to one updating of the controller coefficients. The method has been successful..