基于多目标差值模型的变齿距电磁作动器复合特性半解析优化方法研究

Active vibration isolation technology is an effective method to suppress the low-frequency vibration noise, and electromagnetic actuator is the key component of the active vibration isolation system, whose performance has a serious influence on vibration isolation effect. Compared with fixed pitch electromagnetic actuator, variable pitch actuator has the advantages of good linearity, easy to control, so it has important application value. However, because of mutual coupling among mechanical，electrical and magnetic fields in time and space, the mechanism that structure parameters of the variable pitch electromagnetic actuator effect on its performance is not clear. In addition, In existing optimization methods about the coupling system of mechanical，electrical and magnetic multiple physical fields, the finite element method is of high precision and the large amount of computation, and it is unsuitable for the multi-objective performance optimization; Analytic method can leads to model and computational complexity, and it is difficult to determine the boundary condition of its model. In this study, the variable pitch electromagnetic actuator as the research object, the research aim is to develop a semi-analytical method suitable for multi-objective composite performances optimization of mechanical，electrical and magnetic coupling multi-physics system. The method will be realized as follow: the experimental design method is used to do quantitative analysis and parameters correlation analysis of variable pitch electromagnetic actuator, and then use the difference between the characteristics of the target and system characteristics in all conditions to establish a multi-objective optimization model, and with semi-analytical method to solve the model sensitivity matrix, using feedforward and feedback to carry out matrix decoupling, solving the optimal model parameters with a variety of optimization, and finally carrying out testing, evaluation, and experimental verification.

主动隔振技术是抑制低频振动噪声的有效方法，电磁作动器是主动隔振系统的关键部件，其性能严重影响隔振控制效果。与定齿距电磁作动器相比，变齿距作动器具有线性好、易控制等优点，因此具有重要的应用价值。然而，由于变齿距电磁作动器机电磁物理场在时空上的耦合，导致其结构参数对性能的影响机理还不清楚。此外，现有机电磁多物理场耦合系统优化方法中，有限元法精度高，但计算量大，并难以胜任系统多目标性能优化；解析法存在模型及计算复杂、边界条件难以确定等问题。本课题以变齿距电磁作动器为研究对象，旨在开发一种工程适用的机电磁多物理场耦合系统复合特性多目标优化的半解析方法。该研究通过实验设计方法开展变齿距电磁作动器参数影响量化及相关性分析，然后利用系统当前特性与目标特性间的差值，建立全工况多目标优化模型，再通过半数值法求解模型敏感矩阵，利用前馈和反馈开展矩阵解耦，多种优化求解模型最优参数，最后开展实验测试及评价验证。

主动隔振技术是抑制低频振动噪声的有效方法，电磁作动器是主动隔振系统的关键部件，其性能严重影响隔振控制效果。本课题利用FEM方法建立该电磁系统静态及动态特性模型，分析了齿高、线圈匝数、齿数、气隙、衔铁厚度等参数对电磁力的影响，并研究了驱动电压、能量损失和动态响应之间的关系，揭示了其影响机理；研究还建立了系统集中参数热模型，分析了作动器温升对各个热阻的敏感性；研究根据响应面和遗传算法的多目标优化结果，确定利用系统动静态特性模型和差值模型，研究了粒子群算法和遗传算法等方法在电磁系统优化中的应用。研究显示在全工况平面内，齿高和线圈匝数变化所引起的电磁力变化百分比范围分别为6.3%~13.5%和2.2%~15.7%；齿数组对电磁力变化的影响最大，达到了12.7%~43.6%；衔铁厚度和轭铁厚度对电磁力变化的影响分别为8.0%~25.8%和8.1%~27.7%；气隙对电磁力变化的影响达为7.7%~39.2%。当驱动电流一定时，在小电流情况下，齿数对电磁力变化的影响随位移的增大略微增大；而在大电流情况下，齿数对电磁力变化的影响随位移的增大逐渐减少；当位移一定时，齿数对电磁力变化的影响随电流的增大呈先减小后增大的趋势；驱动电压增加导致驱动电流迅速上升，有利于电磁系统的运动，同时电涡流引起的能量损失也迅速增加。作动器温升对外壳与环境之间的散热热阻最为敏感，当其增加20%时，线圈温度和外壳温度将分别增加6.1%和8.4%。优化结果显示系统峰值电流、峰值脉冲和保持电流减少了20.5%，7.8%和43.9%。响应时间减少了119.%，优化减少了系统能量损耗和铁芯损耗，增加了动态影响。粒子群算法的优化效果略优于遗传算法，但优化耗时明显大于遗传算法。利用研究结论对系统进行优化，经过仿真和试验后，相对传统的定齿距电磁作动器，新结构电磁作动器可以实现在线性度提高93%的情况下，电磁力仅降低了8%。本研究为电磁系统的优化设计奠定了理论基础，新型优化设计的电磁执行器具有良好的应用前景，此外研究对于电磁阀及其它电磁机械系统的优化设计也具有重要意义。