基于LSM的磁轴承自传感方法及其特性研究

Self-sensing and characteristic of magneticbearing based on least squares method

针对磁轴承自传感系统结构复杂和精度不高的问题,对基于最小二乘法的电感计算方法,以及转子位移估计方法、幅度解调法和直接电流测量法等磁轴承自传感系统结构等进行了研究。首先提出了基于最小二乘法的磁轴承线圈电流直接估计转子位移方法和位置控制系统模型,其次基于TMS320F2812和柔性铰链微动位移结构搭建了单自由度磁轴承实验台,最后对该自传感方法的估计位移及其估计误差进行了测试。研究结果表明:在0~250μm量程范围内,该方法估计位移最大绝对误差的仿真结果为-3.49μm,相对误差为1.39%;而估计位移最大绝对误差的实验结果为2.41μm,相对误差为0.96%;该位移估计法不仅提高了估计精度,而且当简化自传感系统结构后,自传感磁轴承运行状态良好。

Aiming at the complex structure and the lower precision of the self-sensing active magnetic bearings(AMBs),the inductance calculation method based on the least square method,the rotor displacement estimation method,the amplitude demodulation method and the direct current measurement method are studied.Firstly,a method for direct estimation of rotor displacement and the model of position control system based on the least square method was proposed.Secondly,based on TMS320F2812 and flexure hinge micro displacement structure,a single degree of freedom magnetic bearing experimental platform was built to test the estimated displacement and error of the self-sensing method.Finally,the position controller of a 1-DOF AMB was implemented in the real-time rig which consists of the digital signal processor TMS320F2812 and micro-position platform based on flexible hinge.The results indicate that the relative error is about 1.39%as the simulation result of absolution error is-3.49μm,and the relative error in test is achieved about 0.96%as the simulation absolution error is 2.41μm within position range of 0~250μm.The displacement estimation method does not only improve the estimation accuracy,but also works well when the structure of the self-sensing system is simplified.