The so-called closed-loop stepper motor is to add an encoder to the stepper motor to achieve the high-precision and low-jitter function of the servo motor, so it is called a closed-loop stepper motor.

In most cases, stepper motors are open-loop, that is, the motor receives PLC control commands through the bus or other methods, and does not perform motion feedback. With such a design, the structure of the entire motor system can be made simpler and the cost can be lowered. Compared with the open-loop control stepper motor, the closed-loop stepper motor adds an encoder structure to the motor, making it a servo system. While receiving the driver pulse, the motor also feeds back the pulse to the driver and even the PLC to realize question-and-answer control with higher reliability. Of course, because of the increased structure, the cost of the motor is higher, which is suitable for projects with relatively high control requirements.

Characteristics of closed-loop stepper motor

1. Compared with traditional stepping products, the closed-loop stepping motor will not lose steps, can ensure the precise positioning of the motor, reduce the vibration of the motor, and run more smoothly. It relies on variable current control technology to save power consumption.

2. Compared with traditional AC servo products, the closed-loop stepper motor does not need complex parameter adjustment, and is more convenient to use. It does not vibrate when it stops at high speed, it is stable at zero speed, and its position response is extremely fast. It is especially suitable for short-distance quick start-stop occasions. Higher torque and smaller installation size.

3. Because of the closed-loop control technology, it does not lose steps like the AC servo system. The position encoder is installed to make the motor have the closed-loop characteristics of the servo motor, which fundamentally solves the problem of lost steps of the traditional stepping motor. 4. Greatly improve the high-speed performance of the motor. The motor torque can be increased.

5. Effectively reduce the heat generated by the motor. The driver output current becomes larger and smaller as the load and speed become larger. 

 6. Shorten the corresponding time of motor acceleration and deceleration. The output of the position response is almost synchronized with the input command in real time, so it is very suitable for the occasions of short-distance quick start and stop and zero-speed steady stop. There is no vibration when the motor brakes. The closed-loop stepper servo drive system has the unique characteristic of holding torque of the stepper motor, which can reach the set position stably and avoid oscillation.

7. The closed-loop stepper motor runs more smoothly and has higher precision. Adopt the most advanced dedicated motor control DSP chip, apply vector control and smoothing filter technology to realize smooth motion control of stepper motor.

8. No need for gain adjustment, very convenient to use. The closed-loop stepping servo system has the dual advantages of the convenience of using the stepping motor and the reliability of the servo system, and can be used very conveniently without cumbersome parameter debugging.