Servo motor and stepper motors are widely used in the control system application, both on the drive control way is similar, are pulse and direction signals to control, but in the use of performance and application of occasions but there is a big difference. Now make a comparison between the use of the performance difference.

A, the control precision

For step two hybrid stepping motor is apart from the Angle of 3.6 degrees, 1.8 degrees commonly, there are also some stepper motor step up the performance from the Angle of smaller. And control precision of the ac servo motor by the motor shaft after the rotary encoder. For the line with a standard 2500 encoder of the motor, drive due to the internal used four frequency multiplication technology, its amount of pulse is 360/10000 = 0.036 degrees, the step from the Angle of 3.6 degrees of one percent of the stepper motor.

Second, the running performance

Stepper motor control mode for open loop control, start frequency is too high or the load is too large, easy to lose step and blocking the phenomenon of turn, stop at high speed easily appeared when phenomenon, so as to ensure the control accuracy, should handle the ascending and descending speed problem. Ac servo drive system for closed-loop control, the drive motor encoder feedback directly for sampling, internal position loop and speed loop, general won't appear step motor lose step or overshoot phenomenon, more reliable control performance.

Three, speed response performance

Stepper motor speed generally accelerate from 0 to work requires 200-400 milliseconds. Better acceleration performance of the ac servo system, accelerate from 0 to the rated speed need only a few milliseconds, can be used for quick start-stop control occasions.

To sum up, servo motor in many performance is better than that of step motor, but in some occasion not high demand also often use stepper motor to do dc motor. In our college students competition freescale smartphone solutions, used for dc motor and using coaxial light code disc to calculated the displacement feedback speed, while easyarm sponsored the national computer mouse game, the first computer mouse is controlled by step motor to carry out simple, positioning, its code is concise, simple control is very suitable for the control of auxiliary control system. But the slower pace in the second edition consider stepping motor, and prone to throw step phenomenon but improvement became a dc motor, highlights the speed of the "race" in the competition this term. It seems is better or weak also depends on the specific application and cost budget.