Stepping motor is an actuator that converts electrical pulses into angular displacement. When the stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle (and step angle) in the set direction. It is also for this reason that we can control the angular displacement by controlling the number of pulses sent by the single-chip microcomputer, PLC, controller, etc., so as to achieve the purpose of accurate positioning; we can also control the speed and acceleration of the motor rotation by controlling the pulse frequency, thereby To achieve the purpose of speed regulation.

The accuracy of a traditional stepping motor is determined by the number of phases of the motor and the subdivision of the drive. For example, the precision of a 5-phase motor is greater than 3 phases, and the accuracy of 3 phases is greater than 2 phases; the precision of a high-subdivision drive is greater than that of a low-subdivision drive. In high subdivision, there is often only resolution but no precision.

The subdivision technology of the stepper motor is essentially an electronic damping technology. Its main purpose is to reduce or eliminate the low-frequency vibration of the stepper motor, and improving the operation accuracy of the motor is only a side function of the subdivision technology. For example, for a two-phase hybrid stepping motor with a step angle of 1.8°, if the subdivision number of the subdivision driver is set to 4, then the motor's operating resolution is 0.45° per pulse. Can the accuracy of the motor reach or approach 0.45°, also depends on other factors such as the subdivision current control precision of the subdivision driver. The larger the subdivision number, the more difficult it is to control the precision.

Method 2 is to use a closed-loop stepper motor. Its accuracy does not depend on the number of phases of the motor, but depends on the accuracy of the motor's encoder. When working, according to the encoder installed on the motor shaft, the current command output signal is fed back in real time. The command input signal is compared with the actual output signal to generate a position deviation, and then input to the control system for position compensation control, and real-time correction of the motor shaft The position deviation can realize the stepping motor without losing steps.