1. The so-called "loop" of the position loop is not what we call a PID closed-loop, and the position cannot be adjusted through a regulator like the speed and current magnitude;
2. The position of the motor rotor and moving body can be detected using either an encoder or a position detection method, so servos have input interfaces for direct position detection signals!
3. The so-called method of motion control mainly depends on which motion parameter of the moving body is controlled: 1) Torque control mode: refers to the closed-loop control of motor current, such as the winding and unwinding control system; 2) Speed control mode: refers to the speed closed-loop control mode, such as the control of spindle speed in machining; 3) Position control mode: refers to the position control of the moving body, such as the feed control of the machining tool;
4. The differences between the three control modes: 1) Torque control mode, the motor current is controlled while the speed is uncontrolled. When the load torque is small, the speed is fast. Conversely, when the load torque is large, the speed is slow and the speed is passively changing, while the current and torque are actively changing; 2) Speed control mode, the speed of the motor is controlled, and the current is not controlled. When the load torque is small, the current is small. Conversely, when the load torque is large, the current is large, and the magnitude of the current changes passively, while the speed changes actively; 3) Position control mode, as long as it is to control the displacement or position of the moving body, the speed can be large or small, and the current can be large or small. The control of current and speed serves for the control of displacement or position, and is in a position that assists, coordinates, obeys, and needs; 4) All three modes have the "start and stop" of the motor, except for the position control mode. The "start and stop" of the motor are related to the determined "starting point" and "end point", and it is the determined "starting point" and "end point" that determine the "start and stop" of the motor!