说明：  通过步进电机的数学模型对二相步进电机进行仿真，并通过卡尔曼滤波处理数据，最终通过处理后的数据预估两相步进电机的相电流和相电压。
(The mathematical model of the stepping motor is used to simulate the two-phase stepping motor, and the data are processed by Kalman filter. Finally, the phase current and phase voltage of the two-phase stepping motor are predicted by the processed data.)