1, control accuracy
The more the number of phases and the number of beats of the stepper motor, the higher the accuracy. The servo motor takes the block of the encoder. The more the scale of the encoder, the higher the accuracy.
2, control method
One is open loop control and the other is closed loop control.
3, low frequency characteristics
The stepping motor is prone to low-frequency vibration at low speed. When it is working at low speed, damping technology or subdivision technology is generally used to overcome the low-frequency vibration phenomenon. The servo motor runs very smoothly, and vibration does not occur even at low speed.
4, the frequency characteristics
The output torque of the stepper motor will decrease with the increase of the speed, and the AC servo motor will be the constant torque output.
5, overload capacity
Stepper motors generally do not have overload capability, while AC motors have a strong overload capability.
6, running performance
The control of the stepping motor is open-loop control. If the starting frequency is too high or the load is too large, it is easy to lose step or block. When the speed is too high, the over-shooting phenomenon is easy to occur. The AC servo drive system is closed-loop control, and the drive can be directly The motor encoder feedback signal is sampled, and the position loop and the speed loop are internally formed. Generally, the stepping motor is lost or overshooted, and the control performance is more reliable.
7, speed response performance
It takes hundreds of milliseconds for the stepper motor to accelerate from standstill to the working speed. The AC servo system has better acceleration performance, generally only a few milliseconds, and can be used in control situations requiring fast start and stop.
