This paper presents an innovative seat suspension with variable stiffness and variable damping (VSVD) via magnetorheological fluid dampers to enhance ride comfort. The VSVD seat suspension is developed based on an innovative structure with springs in series and damping units, and its principles of VSVD and vibration attenuation are evaluated theoretically. The proposed VSVD seat suspension is then manufactured and tested. The test results illustrate that the equivalent stiffness of the seat suspension with power on (I s =2.0 A current) increased to 186% and the equivalent damping (I d =1.0 A) raised to 520% compared to the seat suspension with no current applied. The evaluation of vibration-attenuation capability of the seat suspension is conducted by employing Fuzzy logic controls and both harmonic and random signals are considered as vibration excitations. The experimental data show that the proposed seat suspension with controlled stiffness and damping results in lower seat acceleration compared to a passive seat or one with traditional damping control.

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Inverse models for magnetorheological (MR) devices can be used to calculate the command current required for the MR damper to generate the desired forces. Such models are of great importance in the development of semi-active vibration control. Nevertheless, it is difficult to generate inverse dynamic models because of the inherent nonlinearity of MR dampers. In this paper, we present an adaptive method for establishing the inverse model and describe the corresponding optimization algorithm. Unlike most inverse models, our self-updating model can be adjusted to describe the dynamic characteristics of MR dampers under changes in the external incentives. Experiments under different conditions verify the effectiveness of the proposed inverse model. A comparison between the proposed model and a traditional model with fixed parameters shows that the error can be reduced by approximately 20%. This demonstration of a self-updating inverse model expands the description of MR dampers and provides a new idea for vibration control under varying conditions.

A magnetorheological elastomer (MRE) is a type of particle–matrix composite material, whose properties depend on the strain to which it is subjected in different applications.

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