Optimization design of stepped variable gap MR damper based on genetic algorithm

Here, aiming at problems of limited damping force adjustment ränge, large volume and high energy consumption of magnetorheological (MR) dampers used for lower limb prosthetics, a stepped variable gap MR damper was proposed. The damper could adjust Output damping force by Controlling coil current and changing damping gap according to different gait needs of human body. Structure and working principle of the stepped variable gap MR damper were described, its damping force calculation model was established and magnetic circuit analysis was performed. On the premise of meeting damping force requirements of lower limb prosthetics, taking the minimum power of damper and the minimum piston volume as the optimization objectives, key structural parameters of the stepped variable gap damper were optimized with multi-objective genetic algorithm to obtain the optimal structural size. Magnetic field and mechanical Performance of the optimized damper were simulated to verify the rationality of the optimized results. The results showed that the optimized damper reduces total power by 23. 3% and piston volume by 28.4% under the condition of satisfying the design requirements for Output damping force; the results can provide a reference for optimization design of MR dampers for prosthetics. © 2024 Chinese Vibration Engineering Society. All rights reserved.