Servo motors are generally controlled by three circuits, which are three closed-loop control negative feedback PID control systems. PID circuit is the current circuit and implemented inside the servo controller. The output current from the controller to the motor is based on the check of Hall elements, negative feedback current is set based on PID, and output current is adjusted to be as close as possible to the set current. The current circuit controls the motor torque, so the controller has less operations and less daily dynamic responses and should be faster in torque regulation mode. Though there are many control modes available in servo motor, Gator Precision, one of China top 10 satisfactory rotor factories integrating mold manufacturing, silicon steel sheet stamping, motor assembly, production and sales, will here talk about the three most commonly used control modes in a servo motor.
The main control modes in servo motor include torque control mode, position control mode and speed mode.
1. Torque control mode. In this mode, the output torque of the motor shaft is set through external analog input or direct address assignment. For example, the output torque of the motor shaft is 2.5Nm when the external analog is set to 5V. When the motor rotates with a shaft load less than 2.5Nm and the external load is equal to 2.5nm (above 2.5nm), the motor is hard to rotate. When the servo motor reverses (generally under the force load), the setting of analog quantity can be changed in real time by changing the torque setting or by changing the value of relative address according to the communication.
2. Position control mode. Position control mode generally specifies the speed ratio through pulse frequency of external input and the perspective through the number of pulses. The speed and offset of some servo motor drivers can be assigned directly through communication. In this mode, the speed and position can be strictly controlled, so position control mode is generally used for positioning of CNC lathes and printing equipment.
3. Speed mode. The speed can be controlled according to analog input or single pulse frequency. When the outer ring PID control of the control device can be used, the speed mode can also be positioned, but be sure to feed the position data signal of the motor or direct load to the top level for operation. Servo motor rotor core companies find the position mode is also applicable to the outer side of the direct load to check the position data signal, where only the motor speed is checked at the servo motor shaft side, and the position data signal is provided by the direct check device on the load side. By doing so, the deviation in the intermediate drive will be reduced and the positioning accuracy of the whole system will be improved.
Post time: Jun-06-2022