Identifying a linear parameter-varying (LPV) model of a nonlinear system from local experimental data is still a problem which deserves attention. Many difficulties related to the deter-
Keywords linear parameter-varying model · analytic modeling · robotic manipulator · non-smooth cost function · numerical optimization
IntroductionWhen models of robotic systems are required, a standard solution consists in resorting to a white-box model obtained by combining the laws of physics governing the behavior of the system. Their descriptions are usually based on the EulerLagrange equations and the virtual work principle [9]. Interesting from a theoretical point of view, the exclusive use of the standard laws of physics makes the final model quite complex and requires an accurate knowledge of the manipulator as well as high-level skills in robotics especially when different robot structures are handled. This is all the more true when the user wants to have access to physical parameters of the system which are imperfectly known. In order to circumvent these difficulties, efforts dedicated to robot identification are more and more made in industry [17]. However, a direct identification of a non-linear black-box model is often complicated because• strong non-linearities may vary with the working conditions can appear, • the development of a global non-linear model structure can rely on strong assumptions such as a uniform density of the manipulator segments or the nature of the deformations if any.