Friction Identification Based upon the LuGre and Maxwell Slip Models

Three friction identification methods, designated as the LuGre (LG) method, the Non-Linear Regression(NLR) method, and the Dynamic Non-Linear Regression with direct application of the eXcitation (DNLRX) method,are postulated. The first employs the LuGre model structure, the second the basic Maxwell Slip modelstructure, and the third an extended version of it. The Maxwell Slip model structure accounts for thepresliding hysteresis with nonlocal memory, but is confined to providing constant sliding friction. Thislimitation is circumvented by the extended version postulated, where additional dynamics are introduced. Inall methods identification is based upon signals obtained from a single experiment. The methods are assessedvia laboratory signals, and the DNLRX is shown to achieve the best overall performance, followed by the NLRand the LG methods.