Suppression of Current Quantization Effects for Precise Current Control of SPMSM Using Dithering Techniques and Kalman Filter
Suppression of Current Quantization Effects for Precise Current Control of SPMSM Using Dithering Techniques and Kalman Filter
复制标题
DOI：
10.1109/tii.2014.2307195
复制
发表时间：
2014-02
影响因子：
12.3
通讯作者：
Hongzhong Zhu;H. Fujimoto
中科院分区：
文献类型：
--
作者：
Hongzhong Zhu;H. Fujimoto
许多机电系统需要高精度的电流控制来改善其静态和动态性能。然而，测量系统固有的电流测量误差降低了控制精度，因为电机电流不能保证遵循期望的参考。本文研究了模数转换器引起的量化误差。提出了结合卡尔曼滤波的抖动技术来抑制量化效应。首先，设计了两种抖动系统，即减法抖动系统和非减法抖动系统，对量化误差进行白化。在非减法抖动系统的设计中，利用测量噪声的概率特性使测量噪声水平最小化。然后，设计了卡尔曼滤波器，从抖动电流测量中估计出真实电流信号。根据所提出的抖动技术，由于总测量误差的方差在理论上是可计算的，因此卡尔曼增益可以解析确定。最后，利用高精度定位系统进行了仿真和实验，验证了所提方法的有效性。
High-precision current control is demanded for many mechatronic systems to improve the static and dynamic performances. However, current measurement error inherent in the measurement system degrade the control accuracy, since the motor currents are not guaranteed to follow the desired references. In this paper, quantization error caused by analog-to-digital converters is studied. The dithering techniques combined with Kalman filter are proposed to suppress the quantization effects. First, two dithered systems, including the subtractively dithered and nonsubtractively dithered systems, are designed to whiten the quantization error. In the design of nonsubtractively dithered system, the probability characteristic of the metering noise is utilized to minimize the measurement noise level. Then, Kalman filter is designed to estimate the real current signals from the dithered current measurements. Since the variance of the total measurement error is theoretically calculable according to the proposed dithering techniques, Kalman gain can be determined analytically. Finally, simulations and experiments are performed to verify the effectiveness of the proposed approaches using a high-precision positioning system.