变齿距电磁作动器优化设计

Optimal Design of Variable Tooth Electromagnetic Actuator

针对传统定齿距电磁作动器线性度差的问题，通过磁路分析建立了变齿距电磁作动器的解析模型。在此基础上，分析了气隙、定动子齿宽差、线圈匝数、动子半径等参数对作动器性能的影响，发现定动子齿宽差对作动器的线性度具有重大影响，从理论上揭示了采用变齿距结构实现良好线性度的必要性，并且良好线性度的实现需要牺牲一定的电磁力。为了尽可能提高变齿距电磁作动器的线性度，同时不至于使电磁力降低太多，采用遗传算法对其进行优化设计。结果表明，遗传算法参数设置的不同对优化结果的影响很小，相比于定齿距电磁作动器，变齿距电磁作动器可以实现线性度提高93．08％时，电磁力仅降低8．22％。最后，利用样机试验验证的有限元模型对优化后的方案进行仿真计算，计算结果证明优化后的作动器在0～3mm位移范围内具有良好的线性性能，同时验证了所建立解析模型的有效性。

As one of the most structure, linearity has major imp mportant performance indexes for electromagnetic actuator with tooth act on the vibration controlling effect. However, traditional fixed tooth electromagnetic actuator has poor linearity. To solve this problem, the analytical model of variable tooth electromagnetic actuator was worked out by analyzing magnetic circuit. Influence rules of several parameters, such as air gap, the difference between tooth width of stator and active cell, coil turns and the radius of the active cell, on actuator performance were analyzed based on the analytical model, indicating that the difference between tooth width of stator and active cell had great influence on the linearity of variable tooth electomagnetic actuator. And the necessity of applying variable tooth to gain good linearity was revealed theoretically and the realization of good linearity needed to be at the expense of decreasing electromagnetic force. To improve the linearity of variable tooth electromagnetic actuator as much as possible and minimize the decrease of electromagnetic force at the same time, genetic algorithm was applied to the optimal design. The results showed different setting for genetic algorithm parameters had negligible effect on optimization results and that compared with the fixed tooth electromagnetic actuator, variable tooth electromagnetic actuator can improve linearity by 93.08% under the condition of electromagnetic force was only dropped by 8.22%. Finally, the simulating calculation for optimized scheme was carried out with the finite model which was verified by the experimental results of the processed prototype, and calculation result proved that the optimized actuator had good linearity in the displacement range of 0 -3 mm, meanwhile, it validated the analytical model.