Advances in the Dynamics of Magnetorheological Actuators

Short response time of magnetorheological (MR) valve is important parameter influencing performance of the suspension system controlled by some of fast semiactive algorithm. The main sources of MR actuator’s response time were identified as particle microstructure development in MR fluid, driving electronic response time caused by inductance of the coil, eddy currents in the magnetic circuit and MR actuator compliance. The response time of MR actuator can be significantly reduced by couple of approaches. The rise or drop of electric current can be reduced using over-voltage method and by multi coil design. The effect of eddy currents can be limited using material or shape approach. Experimental results showed that the response time up to 1.3 ms can be reached for magnetorheological damper with structured magnetic circuit.