In this paper, the feasibility of using a magnetorheological (MR) fluid-based system for motion control is studied
based on the hysteretic biviscous model of the MR damper. A feedback control system is designed to synchronize
the motion of the two masses in a two degree of freedom spring-mass-damper system subject to an unknown
disturbance. The controller performance is evaluated numerically. For the derivation of the control law, a
quadratic Lyapunov function, which is a function of the relative position and velocity of two masses, is considered.
The control input (current) is obtained by minimizing the derivative of the Lyapunov function along the trajectory
of the system. In the computer simulation, it is observed that the controller is effective in synchronizing the two
A simple methodology for identification and quantification of nonlinear effects such as Coulomb friction and backlash is desired for use in condition based maintenance programs for both structural and machine based applications. Typically, structural applications are passive and undergo small vibratory motion when an external excitation is presented to the system. A spring-mass system was used as the structural example. Machine applications are typically active and motion is excited by internal actuation of large motion within the system. An industrial SCARA robot was used as the machine based example. The Hilbert transform was tested for detection and quantification of Coulomb friction in both systems.