1. Hardware control of stepper motor.

The stepper motor rotates the corresponding step angle under the action of the pulse, so as long as a certain number of pulses are controlled, the corresponding rotation angle of the stepper motor can be accurately controlled. However, the windings of a stepper motor must be powered up in a certain order to function properly. Through the control of the input pulse, the process of making the motor winding on and off is called annular pulse distribution.

There are two ways to implement circular allocation. First, the release of computer software. Using the method of look-up table or calculation, the three-way output pins of the computer output the annular distribution pulse signal that meets the speed and direction requirements in turn. This can not only make full use of the software resources of the computer, but also reduce the hardware cost, especially the pulse distribution of the multi-phase motor is more obvious. But because the running of the software will occupy the running time of the computer, the total time of the interpolation operation will increase, thus affecting the running speed of the stepping motor.

The second is the hardware ring configuration, which adopts digital circuit structure or special/special ring distribution device to process continuous pulse signals, and generates ring pulses after circuit processing. Ring-type distributors constructed with digital circuits are usually composed of discrete components (such as flip-flops, logic gates, etc.), which are large in size, high in cost, and poor in reliability.

Second, the composition of the stepper motor open-loop control system.

The armature on-off times of the stepper motor and the power-on sequence of each phase determine the output angular displacement and movement direction. Controlling the pulse distribution frequency can realize the speed control of the stepper motor. Therefore, the stepper motor control system generally adopts open-loop control.