The difference between closed-loop stepper motors and servo motors

The servo motor has the following defects:

1. Unable to stand still: Due to the use of closed-loop control, the structure of the servo motor itself and the characteristics of the motor determine that the servo motor cannot stand still absolutely when stopped. In the case of small load disturbance or good parameter tuning of the servo motor, the servo motor always fluctuates between positive and negative 1 pulse (it can be observed by observing the value of the encoder position on the servo drive, which fluctuates between positive and negative 1). In image processing, this is a factor that affects accuracy.

2. Overshoot: When transitioning from high speed to low speed or stationary, it is inevitable to overshoot for a certain distance before correcting it. When the controller sends a pulse to the servo motor, the servo motor often does not take one pulse, but instead takes three pulses and then returns two pulses. This can be fatal for situations that require one pulse at a time and absolutely do not allow overshoot.

3. Complex debugging: The servo drive often has hundreds of parameters and hundreds of pages of user manuals, which really makes beginners nervous.

4. Low speed creep: At low speeds, the operation of the servo motor will experience creep, also known as crawling.

The closed-loop stepper motor perfectly solves the above problems.

Due to the fact that closed-loop stepper motors are not simply equipped with an encoder, but are designed and developed according to the working principle of servo motor systems.

It uses a 32-bit DSP as the main processor to ensure high response and speed of the entire system, and can adjust the motor current every 25 microseconds,

Equipped with a standard encoder of 10000 pulses per cycle, and a metal encoder disk, it not only ensures accuracy but also high adaptability, stability, and reliability to environment, temperature, and vibration.

Even better than servo motors using glass encoder encoder.

Firstly, the closed-loop stepper motor, as the main body of the motor is a stepper motor, is absolutely stationary when stationary.

Secondly, due to the combination of the characteristics of stepper motors and servo control methods, closed-loop stepper motors will not overshoot (because the characteristic of stepper motors is that they will not overshoot).

Thirdly, debugging and use are very simple, just adjust the positions of the three potentiometers of the driver. Not only can the device manufacturer use it, but also the device user can use it, with extremely low requirements for the user.

Fourthly, the driver uses true sine wave, vector, and filtering methods to control the current, and the minimum speed can be controlled at 0.2 rpm. Moreover, the motor runs very smoothly and stably.

Even servo motors cannot achieve this (generally, servo motors can theoretically achieve 1 rpm, but in practical applications, they cannot achieve 1 rpm, roughly above 5rpm).