BWI Group (Luxembourg)

Magnetorheological (MR) actuators are controllable semi-active devices whose output can be modified with magnetic fields in real-time. Fundamentally, they feature an internal control valve in the form of an electromagnet and an internal flow gap. The electromagnet's core contains a coil assembly. Supplying the electrical current to the coil results in inducing the magnetic field in the flow channel, thus activating the fluid. The effect is reversible and fast. As the MR valves are, by principle, electromagnets, the problem of flux measurement or estimation is crucial for controlling the actuator's output torque or force. Therefore, in this study the author examines the use of the so-called unscented Kalman filter (UKF) for online identification of the induced flux. The approach requires the measurements of input voltage and output current. Thus, numerical simulations have been carried out by the author to test the proposed algorithm. The results reveal that the proposed approach yields promising results although further research is required on tuning the filter and prior to implementing the technique in adaptive control applications.