abstract:
Stepper motor is an open-loop control element stepper motor that converts electrical pulse signals ...
Stepper motor is an open-loop control element stepper motor that converts electrical pulse signals into angular displacement or linear displacement. In the case of non-overloading, the speed and stop position of the motor only depend on the frequency and number of pulses of the pulse signal. , and is not affected by the load change, when the stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle in the set direction, called "step angle", its rotation is fixed The angle is run step by step.
The angular displacement can be controlled by controlling the number of pulses, so as to achieve the purpose of accurate positioning. At the same time, the speed and acceleration of the motor rotation can be controlled by controlling the pulse frequency, so as to achieve the purpose of high speed.
1. The control precision is different. The more phases and beats of the stepper motor, the higher the accuracy. The servo motor takes the block from the built-in encoder. The more scales of the encoder, the higher the accuracy.
2. Different control methods; one is open-loop control and the other is closed-loop control.
3. The low-frequency characteristics are different; the stepper motor is prone to low-frequency vibration at low speed. When it works at low speed, damping technology or subdivision technology is generally used to overcome the low-frequency vibration phenomenon. The servo motor runs very smoothly, even at low speed. Vibration will occur. The AC servo system has the function of resonance suppression, which can cover the lack of rigidity of the machine, and has a frequency analysis function (FFT) inside the system, which can detect the resonance point of the machine and facilitate the system adjustment.
4. The torque-frequency characteristics are different; the output torque of the stepper motor will decrease with the increase of the speed, and the AC servo motor is a constant torque output.
5. Different overload capacity; stepper motors generally do not have overload capacity, while AC motors have strong overload capacity.