What is a servo motor? Working principle and analysis
Servo motors have a wide range of applications in various fields such as robots, manufacturing equipment, and automobiles.
At first contact, its working principle may seem complex. This article will adopt a step-by-step approach to systematically explain the basic working principle, composition, and application of servo motors.

Working principle of servo motor

What is a servo motor?

A servo motor typically refers to an electric motor used to perform position control tasks.
Its characteristic is the ability to control the rotation angle and speed with very high precision, thanks to the special control system of the servo motor.

Basic workflow

The operation of servo motors relies on a "control loop" or "feedback loop" system.
The system mainly covers the following four steps.

1. Instruction input: In this stage, issue an instruction to the system to determine what operation to perform. For example, instructions can be given to rotate the motor to a specific angle.

2. Control: Based on input instructions, the control algorithm determines how the motor operates.

3. Output: Execute the action determined by the control unit. The motor performs actual physical operation in this step

4. Feedback: Measure the actual position and speed parameters of the motor to determine if they match the instruction requirements. This information will be fed back to the next control unit and adjusted as needed.

Through the high-speed and continuous operation of this feedback loop, the servo motor is able to achieve high-precision and high responsiveness operation.

Composition of servo motor

The servo motor is mainly composed of the following four main components:

1. Motor body: As the core of servo motors, the motor body bears the important responsibility of converting input electrical energy into mechanical motion. The type of motor, such as DC motor or AC motor, and its characteristics (torque, speed, etc.) in the process of converting electrical energy into mechanical motion, will have a significant impact on the final control performance of servo motors.

2. Feedback sensor: The feedback sensor is used to detect the current position and speed of the motor. These pieces of information are used to compare the expected operating status of the system with the actual operating status of the motor. Feedback sensors come in different types of products such as photoelectric encoders and rotary transformers.

3. Control circuit: The control circuit is responsible for exchanging information between the motor body and feedback sensors, generating control instructions, and providing suitable electric drive for the motor. This section determines the accuracy and responsiveness of motor control.

4. Power supply: The power supply is responsible for providing the necessary electricity for the operation of the motor. Servo motors usually have strict requirements for high-precision control, and the quality and stability of the power supply are crucial factors.

Servo motors are composed of these elements that support their high-precision control performance. The four parts of the motor body, feedback sensor, control circuit, and power supply work together to enable the servo motor to perform exceptionally well. A deep understanding of the characteristics and functions of these constituent elements is of great significance for designing and applying servo motor control systems more efficiently.

Most industrial machinery usually has very high requirements for precision and reliability in operation, and servo motors play an important role in it due to their precise positioning ability and high torque.
Taking Computer Numerical Control (CNC) as an example, servo motors can accurately move cutting tools to the target position, thereby achieving the machining of complex and precise shapes.