The driver controls the three-phase U/V/W electricity to form an electromagnetic field, causing the rotor to rotate under the influence of the magnetic field. Simultaneously, the motor encoder feeds back signals to the driver. The driver compares the feedback value with the target value to adjust the rotor's rotation angle. The accuracy of a servo motor depends on the accuracy (number of lines) of the encoder. It is divided into DC and AC servo motors. Its main characteristic is that when the signal voltage is zero, there is no self-rotation, and the speed decreases uniformly as the torque increases. Understanding the basic structure of a servo motor, its working principle, operating characteristics, and applications is crucial for proper selection and use. What are the characteristics of the working principle of a servo motor?
1. What is a servo motor?
A servo motor, also known as an actuator motor, is an actuating element in a control system that converts electrical signals into angle or velocity on a shaft to drive the controlled object. A servo motor, also called an actuator motor, is an actuating element in an automatic control system that converts received electrical signals into angular displacement or angular velocity output on the motor shaft.
It is divided into DC and AC servo motors. Its main feature is that when the signal voltage is zero, there is no self-rotation, and the speed decreases uniformly as the torque increases.
2. The most important characteristic of servo motors
The servo motor rotates when a control signal is input; it stops rotating when no control signal is input. The speed and direction of the servo motor can be changed by altering the magnitude and phase (or polarity) of the control voltage. Since the 1980s, with the development of integrated circuits, power electronics technology, and AC speed control technology, permanent magnet AC servo drive technology has made significant progress. Leading motor manufacturers worldwide have launched their own AC servo motor and servo drive product lines, continuously improving and updating them.
AC servo systems have become the main development direction of modern high-performance servo systems, putting traditional DC servo systems at risk of obsolescence. Since the 1990s, commercial AC servo systems worldwide have been driven by fully digitally controlled sinusoidal motors. The development of AC servo drives in the transmission field is progressing rapidly.
3. Compared with ordinary motors, servo motors have the following characteristics.
(1) Wide speed range. The speed of the servo motor can be continuously adjusted within a wide range as the control voltage changes.
(2) The rotor has low inertia, so it can start and stop quickly.
(3) It has low control power, strong overload capacity, and good reliability.
4. Typical applications of servo motors in automatic control systems
Siemens, Kollmorgen, Panasonic, and Yaskawa
What are the characteristics of a servo motor's working principle? In summary, AC servo systems are superior to stepper motors in many aspects. However, in some less demanding applications, stepper motors are often used as the actuator. Therefore, during the design of a control system, it is necessary to comprehensively consider factors such as control requirements and cost to select a suitable control motor.
