A sliding mode control strategy for active horizontal seat suspension under realistic input vibration

In the paper, an innovative active control of a horizontal seat suspension system is discussed in context of realistic input vibration that occurs in the cabins of agricultural tractors. The vibration reduction system is represented by the state-space model and its numerical parameters are determined experimentally. For such a reliable mathematical representation of the system dynamics, the finite-time sliding mode controller is successfully designed for different spectral classes of the random excitation signal. A multi-objective control strategy is implemented in order to satisfy opposite requirements, that is, at the limited value of active force, a horizontal vibration of the seated human body is considerably reduced, but the suspension travel does not exceed unacceptable stroke of the system. Laboratory measurements of the seated human body have shown improved comfort of drivers under fore-and-aft vibrations.