Application and Comparison of Nonlinear Estimation Strategies on a Magnetorheological Hysteretic Force Model

The main goal of estimation theory is to minimize state error estimation while maintaining robustness. While the Kalman filter produces the optimal estimate for known linear systems with Gaussian noise, most electromechanical systems such as magnetorheological dampers contain nonlinearities. Nonlinear strategies such as the extended Kalman filter and smooth variable structure filter can be used to estimate the force produced by a damper given its velocity and acceleration and applied current. This paper compares the extended Kalman filter and the smooth variable structure filter on a magnetorheological damper that is subject to harmonic excitation. The purpose of this study is to apply and compare estimation methods that may be used in conjunction with a reliable controller for applications on a magnetorheological damper.