In order to compare the performance of the different control methods, two different excitations
were employed: one was a swept sine excitation and the other a random excitation. To
assess the above three semi-active control methods, the responses of the sprung mass under
constant damping are used as a reference. For all three on–off controllers, the damper is
applied a serious value of current for the on state and zero current to the MR damper for the
off state.