Differences between the three control modes of servo control

Servo control method

There are three control modes: speed control, torque control, and position control. Speed ​​control and torque control are both controlled by analog quantity, and position control is controlled by sending pulses.

▶If you have no requirements for the speed and position of the motor and just want to output a constant torque, of course you should use the torque mode.

▶If you have certain accuracy requirements for position and speed, but are not very concerned about real-time torque, it is better to use speed or position mode.

▶If the upper controller has better closed-loop control function, speed control will have better effect.

▶If the requirements are not very high, or there is basically no real-time requirement, the position control method does not have very high requirements for the upper controller.

Differences between the three control modes of servo motion control

1. The so-called "loop" in the position loop is not what we call a PID closed loop. The position cannot be adjusted by a regulator like the speed and current .

2. The position of the motor rotor and the moving body can be detected by encoder or directly by position detection, so the servo has an input interface for direct position detection signals !

3. The so-called motion control method mainly depends on which motion parameter of the moving body is controlled:

1) Torque control mode: it is the closed-loop control of motor current, such as winding and unwinding control system;

2) Speed ​​control mode: It is the speed closed-loop control mode, such as the control of the spindle speed in machining;

3) Position control mode: it is the position control of the moving body, such as the feed control of the turning tool in machining;

4. Differences between the three control modes:

1) Torque control mode, the motor current is controlled, but the speed is not controlled. When the load torque is small, the speed is fast. On the contrary, when the load torque is large, the speed is slow. The speed changes passively, while the current and torque change actively.

2) Speed ​​control mode: the motor speed is controlled, but the current is not controlled. When the load torque is small, the current is small. On the contrary, when the load torque is large, the current is large. The current changes passively, while the speed changes actively.

3) Position control mode: as long as the displacement or position of the moving body is controlled, the speed can be large or small, the current can be large or small, and the control of current and speed serves the control of displacement or position, and is in a position of assistance, coordination, obedience, and need;

4) All three modes have the function of starting and stopping the motor, but in the position control mode, the starting and stopping of the motor are related to the determined starting point and end point. It is the determined starting point and end point that determine the starting and stopping of the motor!