基于FPGA的步进电机电流优化控制策略

Optimized Current Control Strategy for Stepper Motor Based on FPGA

针对一般步进电机在进行高精密控制时存在的问题,提出了一种基于现场可编程门阵列(FPGA)的步进电机电流优化控制策略.利用异步触发器对脉冲宽度调制(PWM)信号进行恒频斩波,从而降低功率器件的开关频率以及减小地线信号的耦合干扰;同时采用电流的快、慢混合衰减模式,保证步进电机在高速运行时的快速响应以及在低速运行较低的电流纹波.最后在某型号高精密微型操作仪上进行实际测试,实验结果满足各项指标要求,且运行精度高、噪声低.该方法不仅适用于高精密控制也可应用于多轴伺服系统的控制,并且便于扩展与移植.

For problems inherent in the stepper motor control on high precision occasions, an optimized current control strategy is proposed based on the field programmable gate array （FPGA）. By using an asynchronous trigger to chop the pulse width modulation （PWM） signal with a constant frequency, the switching frequency and coupling interferences of the ground signal are reduced. In addition, by adopting the fast and slow mixed current decay mode the stepper motor responds rapidly when running at high speed, while a low current ripple is obtained when running at low speed. The method is then tested on a high precision micro-manipulator, and experimental results meet the requirements of various indicators with a high running accuracy and low noise. The proposed method is not only suitable for high-precision control, but it can also be applied to a muhiaxis servo control system, and is facilitated for extension and transplantation.