Working principle of DC servo motor_Speed ​​regulation method of DC servo motor

Working Principle of DC Servo Motor

The DC servo motor is a common precision control motor whose working principle is based on the flux law and Faraday's law of electromagnetic induction.

A DC servo motor consists of a DC power supply, a motor, an encoder, and a controller. When a DC power supply is applied to the motor, a magnetic field is generated in the motor. This magnetic field is generated by the flux coil between the armature and the permanent magnet. Next, the controller applies a control signal to the armature. This signal can be a pulse width modulation (PWM) signal, and its frequency is generally between a few kilohertz and tens of kilohertz. When the control signal changes, it causes a change in the magnetic field inside the motor, so that the motor will rotate.

The encoder is used to detect the angle and position of the motor. By feeding the encoder signal back to the controller, the controller can control the rotation speed and direction of the motor in real time. The controller calculates the output value of the control signal by comparing the encoder feedback signal with the expected signal, and transmits the output signal to the motor.

The advantages of DC servo motors are fast response speed, wide speed range, high precision, high efficiency and good reliability. Therefore, they are widely used in industrial automation, robotics, medical equipment, semiconductor manufacturing and other fields.

DC servo motor speed regulation method

There are many ways to adjust the speed of a DC servo motor. Here are some of the commonly used methods:

Voltage modulation method: The motor speed is adjusted by changing the output voltage of the DC power supply. This method is simple and easy, but the speed regulation range is limited.

Pulse width modulation method: Change the speed of the motor by changing the duty cycle of the PWM wave. This method can achieve a larger range of speed regulation, but it requires the use of high-frequency PWM signals, so it has higher requirements for the controller.

Current modulation method: The speed of the motor is changed by changing the current of the DC motor. This method can achieve a larger speed regulation range, but it needs to be adjusted according to the characteristic curve of the motor and has high requirements for the controller.

PI control method: By performing feedback control on the motor speed and using proportional and integral control algorithms to adjust the motor control signal, the motor output speed can be as close to the desired speed as possible. This method can achieve higher control accuracy and stability.

Fuzzy control method: By establishing a fuzzy control model of the motor and using the fuzzy logic control algorithm to adjust the motor's control signal, the motor's output speed can be as close to the desired speed as possible. This method can deal with some complex nonlinear control problems.

It is necessary to select a suitable speed regulation method based on the actual application requirements and motor characteristics, and adjust the controller parameters according to the specific situation.