基于非对称采样SPWM的步进电机控制器设计

Design of Stepper Motor Controller Based on Asymmetric Sampling SPWM

为了满足当前工业现场中对步进电机控制系统模块化、高效率、高精度的需求,提高步进电机控制器动态调整驱动信号脉宽的效率,实现稳定的恒力矩控制。针对步进电机的工业应用场景需求,采用高性能的ARM系列微处理器STM32F407VGT6和全桥驱动器L298 N,搭建了步进电机控制器实验平台;基于集成运放芯片MAX44284设计了步进电机相电流检测电路;设计了基于非对称采样的SPWM在线生成算法,该算法使步进电机控制器能够实时根据电机负载变化对驱动信号脉宽进行调节以保持稳定的正弦阶梯电流,实现细分状态下步进电机的恒力矩输出。实验结果表明,搭建的步进电机测试平台能够稳定保持步进电机相电流呈正弦变化,控制器输出脉冲宽度可根据负载变化实时调整;在多种细分状态、转速下,实际转速误差保持在0.6%内。详细阐述了控制器的功能、系统架构、软硬件设计,实现了步进电机闭环控制,并支持CAN总线接口通信。

In order to meet the requirements of modularization,high efficiency and high precision of the stepper motor control system in the current industrial field,the efficiency of the stepper motor controller to dynamically adjust the pulse width of the driving signal was improved,and stable constant torque control was achieved.In view of the industrial application scenario requirements of stepper motors,the highperformance ARM series microprocessor STM32F407VGT6 and full-bridge driver L298N were used to build a stepper motor controller experimental platform;based on the integrated operation amplifier chip MAX44284,the stepper motor phase current was designed.An on-line generation algorithm of SPWM based on asymmetric sampling was designed.The algorithm enabled the stepper motor controller to adjust the driving signal pulse width according to the motor load change in real time to maintain a stable sinusoidal step current and realize the constant force distance output of the stepper motor in the subdivision state.The experimental results show that the built stepper motor test platform can stably maintain the sinusoidal change of the stepper motor phase current,and the output pulse width of the controller can be adjusted in real time according to the load change.Under various subdivision states and speeds,the actual speed error remains unchanged within 0.6%.The controller′s function,system architecture,software and hardware design were elaborated,the stepper motor closed-loop control was realized,and CAN bus interface communication was supported.