1、 Torque control
The torque control method is to set the external output torque of the motor shaft through the input of external analog quantity or the assignment of direct address. For example, if 10V corresponds to 5Nm, when the external analog quantity is set to 5V, the motor shaft output is 2.5Nm: if the motor shaft load is lower than 2.5Nm, the motor will rotate forward, when the external load is equal to 2.5Nm, the motor will not rotate, and when the external load is greater than 2.5Nm, the motor will reverse (usually generated under the condition of gravity load). The set torque can be changed by changing the setting of analog quantity instantly, or by changing the value of corresponding address through communication.
It is mainly used in winding and unwinding devices that have strict requirements on the stress of materials, such as wire wrapping device or fiber pulling device. The torque setting should be changed at any time according to the change of winding radius to ensure that the stress of materials will not change with the change of winding radius.
2、 Position control
In the position control mode, the rotation speed is generally determined by the frequency of the external input pulse, and the rotation angle is determined by the number of pulses. Some servo systems can directly assign the speed and displacement through communication. Because the position mode can strictly control the speed and position, it is generally used for positioning devices.Applications such as CNC machine tools, printing machinery, etc.
3、 Speed mode
The rotation speed can be controlled through the input of analog quantity or the frequency of pulse. The speed mode can also be positioned when the outer loop PID control of upper control device is available, but the position signal of the motor or the position signal of the direct load must be fed back to the upper for operation. The position mode also supports the direct load outer ring to detect the position signal. At this time, the encoder at the motor shaft end only detects the motor speed, and the position signal is provided by the detection device at the direct final load end. This has the advantage of reducing the error in the intermediate transmission process and increasing the positioning accuracy of the entire system.
