超磁致伸缩棒磁场强度建模及线圈优化分析

Magnetic Field Intensity Model for Giant Magnetostrictive Rod and Coil Optimization Analysis

超磁致伸缩棒上的磁场强度对超磁致伸缩致动器(GMA)至关重要,因其幅值和上升、下降时间直接影响致动器的输出力和响应时间.建立电压到磁场强度的模型,并提出较合理的线圈优化方案.将线圈充、放电过程简化为一阶RL线性电路的暂态过程,计算得到线圈电流,并根据线圈电流建立超磁致伸缩棒上的磁场强度模型.由模型可知,致动器尺寸有限制时,棒上磁场强度的优化应主要考虑线圈匝数;通过分析线圈匝数对磁场强度稳态值、上升时间和下降时间的影响确定匝数的取值范围.向线圈施加不同频率和幅值的方波电压信号,得到的模型曲线与测得的实验结果相吻合,从而验证了模型的正确性.

The magnetic field intensity of the giant magnetostrictive rod is critical to the giant magnetos- trictive actuator （GMA） , as its amplitude and rise-time and fall-time affect output force and response time of the actuator directly. The magnetic field intensity is modeled from voltage, and rational optimiza- tion program of the coil is proposed. The coil＇ s charging and discharging process is simplified as transient process of a first-order RL linear circuit and the coil current is achieved, and the magnetic field intensity of the rod is modeled from the current. The model shows that the optimization of the rod＇ s magnetic field intensity relies mainly on the coil＇ s circle number when the size of the actuator is restricted. The prefera- ble range of the coil＇ s circle number is determined by analysis of the circle number＇ s influence on steady intensity, rise-time and fall-time of the magnetic field intensity. Square wave voltage signals with changed frequencies and amplitudes are put in the coil to get experimental data. The data＇ s consistency with the model curves verifies the correctness of the model.