Technical Knowledge

What is a closed loop stepper motor?
Release Date : 2020-09-25 18:16:24



Closed loop stepper motor, also called hybrid servo motor. In recent years, it has been rapidly promoted and applied in the fields of medical equipment, in vitro diagnostics (IVD), mobile robots (AGV), intelligent warehousing, modern logistics, and intelligent manufacturing.
What exactly is a closed-loop stepper motor?

 


In simple terms, a closed-loop stepper motor is to add a closed-loop encoder to the conventional drive, which is mainly used for detection and feedback, especially for applications with high torque and low speed.
 
1. The body of the closed-loop stepper motor is a stepper motor, which is absolutely stationary when it is stationary.
 
2. Closed-loop stepper motor combines the characteristics of stepper motor and servo control method, completely without overshoot position positioning (because the characteristic of stepper motor is that it does not overshoot), it surpasses traditional servo motors in medium and low speed applications And gain application advantage.
 
The third adjustment and use are very simple, only need to adjust the position of the 3 potentiometers of the drive, which has very low requirements for users.
 
 
After years of meticulous design, NiMotion has launched the STM series integrated closed-loop stepper motor series products, using the latest ARM core M4 controller in the industry, the main frequency is up to 80MHZ, making the motor response frequency up to 2MHZ, closed-loop stepping The maximum no-load speed of the motor can reach 4000 rpm or more!
Introduction to the basic characteristics of STM series closed-loop stepper motors:
 
(1) Using a high-characteristic magnetic encoder to feedback the position to the high-frequency ARM core processor, the position can be adjusted in real time every 50us, which can quickly respond to position commands, and the position response speed is better than that of various early developments that have been on the market for many years. Products with low characteristics can make the equipment have higher processing accuracy, higher finish and more perfect product details.
 
(2) Better than the traditional servo control technology and the current domestic mainstream hybrid servo, the STM series closed-loop stepping motor can automatically adjust the step length and automatically adjust the current according to the load. Under low load conditions, the current is automatically and quickly adjusted to the minimum, thereby reducing motor noise and heat; when the load is suddenly increased, the current is quickly adjusted to the optimal value in real time to maintain high-precision position control and high-speed operation. Out of step.
 
(3) After the positioning is completed, it remains stable. The STM series closed-loop stepper motor continuously feedbacks through the code disk to detect the difference between the reference position and the actual position. When the closed-loop stepper motor runs to the target position, it stops stably without any vibration, which becomes one of the biggest advantages of this series of closed-loop stepper motors different from traditional servo motors.
 
(4) Simple to use, no parameter setting: traditional servo position PID algorithm needs to adjust the control parameters according to the load to produce the best control effect, and the setting process is more complicated. STM series closed-loop stepper motors realize rapid positioning of closed-loop stepper motors through precise step length adjustment technology, almost no need to set the control parameters of the position loop, which avoids the trouble of parameter setting adjustment during the use of customers.
 
All in all, the closed-loop stepper motor outperforms the traditional open-loop stepper motor in terms of no out-of-step, low motor temperature rise, medium, high speed and large torque, and has become a high-quality product in the field of precision position control and precision speed control in recent years.