Technical Knowledge

Overview of features and functions of servo motors
Release Date : 2020-04-21 18:29:54
Servo motor is specially used for high response speed and high precision positioning system. As a motor that can accurately control the rotation angle and speed, it can be used in various high-precision equipment.

What are the characteristics of servo motors?

 

1. Closed loop control

 
Closed-loop control is achieved by encoder, driver, and motor, so the motor can perform high-precision positioning operations.
The encoder feeds back the rotation position / speed of the motor shaft to the drive.
The driver calculates the error of the pulse signal or analog voltage (position command / speed command) according to the controller and the feedback signal (current position / speed), and controls the rotation of the motor so that the error becomes zero.
The motor finally obtains a termination signal, which signals the completion of the positioning operation.
 
(1) Use pulse signal for position control
The controller inputs the pulse signal, and then controls the speed and stop position according to the pulse number.

Position control chart:

(2) Speed control by analog voltage
Input analog voltage to control the speed.
Speed control chart:
 

(3) Torque control by analog voltage
Input analog voltage to control torque.

Torque control chart:
 

2. Compact structure and high output power

 
The servo motor is compact and light, with high output power.
 

3. Continuous working system

 
The servo motor controls the current according to the state of the load. Due to the high efficiency of the motor and low heat generation, it can be continuously operated within the rated torque. In addition, during acceleration and deceleration, the limited duty cycle area is used to obtain large torque, so that the positioning time can be reduced.
 

4. Wide speed range

 
The torque changes smoothly and steadily from low speed to high speed operation, so you can quickly locate long distances. By running slowly at a low speed and then quickly returning to a high-speed state, the operating cycle of the test equipment can be improved.
 

5. Gear type compatible with large inertia load

 
The servo motor has a limit on the allowable load inertia, but a gear reducer can be used to greatly increase the size of the load that can be driven.