A new invertible model of magnetorheological damper based on sigmoid function

As an intelligent device, the magnetorheological (MR) damper has received extensive attention in many fields. However, in the real-time control system, it is still extremely necessary to develop a simple, accurate and invertible dynamic model of the MR damper. In this work, a new invertible MR dynamic model based on sigmoid function is proposed. According to the experimental data of a common MR damper, it is assumed that the damping force at zero velocity under constant current is only related to current and independent of the excitation frequency. The preliminary sigmoid model based on this hypothesis can better adapt to different frequency excitations while reducing the complexity of the model. In addition, according to the parameter analysis of the proposed preliminary model, the relationship between the parameters and the input current is reasonably simplified, so that the final model can meet reversibility requirements in the control system while ensuring accuracy. In order to evaluate the performance of the proposed model, it is compared with the existing sigmoid models from the literature. The results show that the proposed model has certain advantages in the number of parameters, accuracy and reversibility, which is suitable for the real-time control system.