Design and shape optimization of MR brakes using Nelder-Mead optimization algorithm

Magnetorheological (MR) brakes have attracted many attentions for controlling mechanical systems such as robots, e-bicycles, and haptic devices. A large number of researchers have delved into enhancing MR brake effectiveness. Herein, a new MR brake is proposed in which the braking torque is improved and the configuration is simplified. Numerical simulations were based on finite element method (FEM) was employed to achieve the brake model. In order to verify the obtained results, they were compared with the available ones in the literature and they have a good agreement with each other. Then, the proper brake model was optimized using Nelder Mead optimization algorithm. Results demonstrated 215.75 N m braking torque in the present prototype which is almost 73% higher than the previous model in the literature. In addition, the brake could induce about 125.06 N m torque on the brake disk with nearly half of the coil current used in the previous work. Besides, increase in the number of the disks was not necessarily improved braking efficiency and the size of the MR fluid gaps also influenced the brake operation. In addition, the proposed model in this paper has ease manufacturing procedure which would reduce the fabrication costs.