Since no universal friction model exists and the practical measurement of friction is not straightforwad, this paper presents an experimental method of identifying friction in mechatronic systems. Friction is prehaps the most important nonlinearity that is found in any mechatronic system of moving parts and influences the system in all regimes of operation. For the purpose of improving the performance of mechatronic systems and solving their servo problem, a better understanding of friction behavior in its two basic regimes is needed. In this paper, the two basic friction regimes, viz., presliding with its hysteresis behavior, which is predominantly position dependent, and gross sliding, which is predominantly velocity dependent, are well exposed and identified.

  ISA Transactions, Vol 43, No 2, April 2004, pp 205-216.