We apply retrospective cost adaptive control (RCAC) to a command-following problem for mass-spring systems with unknown contact friction. Dahl, LuGre, and Maxwell-slip models are used to generate the friction force. We consider a single-degree-of-freedom oscillator with control force applied directly to the mass, as well as a noncolocated two-degree-of-freedom oscillator with control force applied to the secondary mass and performance given by the position of the primary mass. For harmonic command following, we show that RCAC achieves internal model control without knowledge of either the friction force or the friction model.
['Mohammad Al Janaideh', 'Dennis S. Bernstein']
Adaptive control of mass-spring systems with unknown hysteretic contact friction