Step motors (also known as stepping motors) were first used to remotely control the torpedo tubes and cannon direction indicators in British Navy English, and later used for similar purposes in the US Navy. A variant of the reluctance motor was first patented in 1919 by Scottish civil engineer C. L. Walker. But commercial production did not begin until 1950.
This engine is used for some robots, educational robots and hobby robots in the smallest half of the industry. They are also widely used in other industries and have the advantage that they do not necessarily require feedback systems and associated costs. However, it is compatible with many feedback devices if necessary and is used for full servo control configuration of medium industrial robots. Because it is a digitally controlled motor, there is no additional cost of digital conversion when connecting the instrument to the computer control system. Normally, the motor flange rotates incrementally in the same step according to the programmed input pulse train. Since the rotor indexes a certain amount for each control pulse, not all positioning errors are accumulated. To determine the final position of the rotor, you need everything needed to count the number of pulses transmitted by the phase windings of the stator coils. The number of pulses per unit time determines the speed of the motor. The rotor can be indexed slowly after each increment, paused after each increment, or quickly produced a continuous action called "rotation" (until a constant rotational speed is reached).
The maximum dynamic torque of the stepper motor occurs at a low pulse frequency. This makes it easy to accelerate loads. When the required position is reached and the command pulse is complete, the arrows are held without the need for a clutch or brake. The rotation moment of the arrow or the actual pitch angle can be obtained from 8 ° to 90 ° depending on the motor selection. Thus a current of 1000 pulses with a nominal pitch angle of 1.8 ° provides an angular displacement of 1800 ° or five complete revolutions. There is also a low speed function that does not require gear deceleration.
