Servo Motor The voltage signal is converted to torque and speed
Servo motor can control speed, position accuracy is very accurate, the voltage signal can be converted into torque and speed to drive the control object. Servo motor rotor speed is controlled by the input signal, and can quickly respond, in the automatic control system, used as an actuator, and has a small electromechanical time constant, high linearity, starting voltage and other characteristics, the received electrical signal Converted to angular displacement or angular velocity output on the motor shaft. Divided into DC and AC servo motor two categories, the main feature is that when the signal voltage is zero no rotation phenomenon, the speed increases with the torque and uniform decline.
1, servo system (servo mechanism) is to make the object position, orientation,
Status, etc. The output controlled control system can follow any change in the input target (or setpoint). Servo is mainly dependent on the pulse to locate, basically can be understood, the servo motor receives a pulse, it will rotate a pulse corresponding to the angle, in order to achieve displacement, because the servo motor itself has a pulse function, so the servo motor every Rotate an angle, will send a corresponding number of pulses, so that the servo motor to accept the pulse formed a response, or called closed loop, this way, the system will know how many pulses sent to the servo motor, and how much pulse back , So that it can be very precise control of the motor rotation, in order to achieve accurate positioning, can reach 0.001mm. DC servo motor is divided into brush and brushless motor. Brush motor low cost, simple structure, large starting torque, wide speed range, easy control, the need for maintenance, but maintenance is not convenient (for carbon brush), resulting in electromagnetic interference, the environment requirements. So it can be used for cost-sensitive general industrial and civilian applications.
Brushless motor small size, light weight, the output of large, fast response, high speed, inertia small, smooth rotation, torque stability. Control complex, easy to achieve intelligent, the electronic commutation way flexible, can be square wave commutation or sine wave commutation. Motor maintenance-free, high efficiency, low operating temperature, electromagnetic radiation is very small, long life, can be used for a variety of environments.
2, AC servo motor is also brushless motor, divided into synchronous and asynchronous motor, the current motion control are generally used synchronous motor, its power range, you can do a lot of power. High inertia, the highest rotational speed is low, and with the power increases and quickly reduced. And thus suitable for low-speed smooth operation of the application.
3, the servo motor internal rotor is permanent magnet, drive control of the U / V / W three-phase electrical formation of electromagnetic field, the rotor in the role of this magnetic field rotation, while the motor comes with the encoder feedback signal to the drive, the drive according to the feedback value Compare with the target value to adjust the angle of the rotor rotation. The accuracy of the servo motor depends on the accuracy of the encoder (number of lines).
AC servo motor and brushless DC servo motor in the functional differences: AC servo is better, because it is sine wave control, torque ripple small. The DC servo is a trapezoidal wave. But the DC servo is relatively simple and cheap.