A hysteresis model and parameter identification for MR pin joints using immune particle swarm optimization

A novel hybrid model is proposed in this paper to describe the highly-nonlinear hysteretic relationship between the torque and angular velocity in a magnetorheological pin joint (MRP). The MRP´s hysteresis loop is modelled by a mixture of hyperbolic and Gaussian functions using the curve fitting technique, resulting in a significant reduction of the model parameters. To identify the model parameters, an immune particle swarm optimization (IPSO) algorithm is employed using torque-angular displacement/velocity experimental data recorded under various loading conditions. To demonstrate the accuracy of the proposed model and the effectiveness of parameter identification process, characterization test data of the smart pin torque and angular velocity are utilized for comparison.