Robust IT-2 Fuzzy Logic Control for Magnetorheological Suspension System With Approximate Hysteresis Nonlinearity

The magnetorheological fluid (MRF) damper is a crucial component for vibration energy absorption and dissipation, and the dynamic performance of the MRF damper can be characterized by the hysteresis function. However, the complexity of the controller design is increased due to the nonlinearity of the hysteresis function. This study proposes a method based on the interval type- 2 (IT-2) fuzzy strategy to address the control issue of the semiactive suspension (SAS) system equipped with the MRF damper. First, a novel IT-2 fuzzy hysteresis (IFH) model is proposed to approximate the hysteresis nonlinearity of the MRF damper. Based on the fuzzification of the hysteresis nonlinearity, the dynamic performance of the MRF-SAS system can be easily expressed by a set of linear functions. Furthermore, to improve the dynamic performance of the MRF-SAS system, a robust type-2 fuzzy logic (RTFL) controller is proposed with the consideration of the control disturbance, actuator saturation constraint, and time-varying delay. Within the framework of feedback control, an adaptive Kalman filter observer is implemented to reduce the measurement cost. Moreover, a quarter-car test rig (QCTR) is built to verify the effectiveness of the proposed RTFL controller. The experimental results show that the performance of the MRF-SAS system with the proposed RTFL controller is improved by an average of 30% in comparison with the passive suspension.