Innovative Microstepping Motor Controller with Excitation Angle-Current Dual-Loop Feedback Control

In this paper, an innovative control method, namely angle-current dual-loop feedback control, is proposed for use with microstepping motors. This method involves adjusting the stator excitation angle and current simultaneously on the basis of the feedback angle of the sensor on the microstepping motor. The proposed method is expected to enhance the positioning accuracy and energy efficiency of stepping motors. The proposed method was tested by implementing it in a microstepping motor control system, which included a core microcontroller unit circuit, dual-H-bridge pulse width modulation drive circuit, current sensing circuit, and angle sensing encoder readback circuit. An algorithm based on the proposed method was developed, and data sampling, storage, and return communication functions, which are convenient for experimental verification, were included in this algorithm. To verify that the proposed method is superior to traditional open-loop control and excitation angle feedback control, a testing platform was used to measure the differences in positioning accuracy and drive power under the three control methods and biased torsion loads. The results indicate that compared with the other two control methods, the proposed control method improves the positioning accuracy and reduces the power consumption of a stepping motor.