Servomotors, also known as actuator motors, are used as actuators in automatic control systems to convert the received electrical signal into an angular displacement or angular velocity output on the motor shaft. Working Principle
1. Servo mainly rely on the pulse to position, basically can be understood in this way, the servo motor receives a pulse, it will rotate 1 pulse corresponding to the angle, so as to realize the displacement, because, the servo motor itself has the function of sending out pulses, so the servo motor will send out the corresponding number of pulses for every angle of rotation, in this way, and the servo motor receives the pulse to form the echo, or called closed loop, in this way In this way, the system will know how many pulses are sent to the servo motor and how many pulses are received back at the same time, so that it can control the rotation of the motor very accurately, thus realizing precise positioning, which can reach 0.001mm.
DC servo motors are divided into brushed and brushless motors. Brushed motor has low cost, simple structure, large starting torque, wide speed range, easy to control, requires maintenance, but easy to maintain (change carbon brushes), generates electromagnetic interference, and has environmental requirements. Therefore it can be used in common industrial and civil occasions which are sensitive to cost.
Brushless motor is small in size, light in weight, large in output, fast in response, high in speed, small in inertia, smooth in rotation and stable in torque. The control is complex and easy to realize intelligentization, and its electronic phase change mode is flexible, which can be square wave phase change or sine wave phase change. Motor maintenance-free, high efficiency, low operating temperature, electromagnetic radiation is very small, long life, can be used in a variety of environments.
2. AC servo motor is also brushless motor, divided into synchronous and asynchronous motors, at present, motion control generally use synchronous motors, its power range is large, can do a lot of power. Large inertia, the maximum speed of rotation is low, and with the increase in power and rapid reduction. Thus, it is suitable for low-speed smooth running applications.
3. The rotor inside the servo motor is a permanent magnet, the driver controls the U/V/W three-phase electricity to form an electromagnetic field, the rotor rotates under the action of this magnetic field, while the encoder that comes with the motor feeds back signals to the driver, who adjusts the angle of rotation of the rotor based on the comparison of the feedback value with the target value. The precision of the servo motor is determined by the precision (number of lines) of the encoder.