What is the difference between open loop and closed loop of stepper motor

Stepper motors can be divided into open-loop stepper motors and closed-loop stepper motors. So the question is, what is the difference between an open-loop stepper motor and a closed-loop stepper motor?

The open-loop stepper motor can be generally understood as sending ordinary letters before, and the content is just fine for the other party to execute. No feedback.

A closed-loop stepper motor is equivalent to sending a registered letter, which needs to be executed by the other party and reported to you. Have feedback.

That is to say, the fundamental difference between an open-loop stepper motor and a closed-loop stepper motor is whether the current running status signal will be fed back.

An open-loop stepper motor has no feedback signal and only executes in sequence. On the contrary, the closed-loop stepper motor feedback signal, and taking corresponding action measures or signal according to the signal stepper motor driver to  feedback to the PLC, the PLC decides the next program processing.

Sometimes, some people refer to closed-loop stepper motors as hybrid servo motors. Next, analyze the advantages of closed-loop stepper motors.

The advantage of closed-loop stepper motors is that closed-loop control improves torque-frequency characteristics.

The second advantage of closed-loop stepper motors is that under closed-loop control, the output power/torque curve is improved, and the current value is determined by the motor load. Therefore, even in the low speed range, the current can be fully converted into torque.

The third advantage of the closed-loop stepper motor is that with closed-loop control, the stepper motor can be automatically and effectively accelerated and decelerated.