Semi-active control of magneto-rheological variable stiffness and damping seat suspension with human-body model

The potential benefits of an MR seat suspension in improving ride quality are investigated. Two magneto-rheological (MR) dampers are devised and manufactured to realise the variable damping and equivalent stiffness capacities of a seat suspension, respectively. After evaluating field-dependent damping characteristics of the MR seat damper, the equation of equivalent variable stiffness is also shown. A seat suspension model with a four-DOF human body model is then formulated. A Human Simulated Intelligent Controller (HSIC) is proposed to attenuate the unwanted vibration of the variable stiffness and damping seat suspension. To validate the control performance of the proposed seat suspension and the control scheme, a numerical simulation is performed under the bump, random and chirp excitations. The result indicates that the proposed seat suspension system with HSIC can significantly improve the driver's ride quality compared to the passive one.