The servo is mainly positioned by Pulse. When the servo motor receives one pulse, it will rotate the angle corresponding to one pulse to realize displacement, because the servo motor itself has the function of issuing pulses, therefore, every time the servo motor rotates an angle, it will emit a corresponding number of pulses, thus echoing the pulses accepted by the servo motor, or called a closed loop, so that, the system will know how many pulses are sent to the servo motor, and at the same time how many pulses are received back, so that the rotation of the motor can be accurately controlled to achieve accurate positioning, can reach 0. 001mm.
The rotor inside the servo motor is a permanent magnet. The U/V/W three-phase electricity controlled by the driver forms an electromagnetic field. The rotor rotates under the action of this magnetic field. At the same time, the encoder provided by the motor feeds back the signal to the driver, the driver compares the feedback value with the target value to adjust the angle of rotor rotation.
The accuracy of the servo motor depends on the accuracy of the encoder (Number of lines). DC servo motors are divided into brush and brushless motors.
The Brush Motor has low cost, simple structure, large starting torque, wide speed regulation range, easy control and maintenance, but convenient maintenance (Change carbon brush), Electromagnetic interference, environmental requirements.
Therefore, it can be used in cost-sensitive ordinary industrial and civil occasions.