The characteristics of two control modes of DC servo motor are briefly described.

There are two control modes of DC servo motor: open-loop control and closed-loop control.

Open-loop control means that the output of the control system is directly controlled by input, and there is no feedback loop. This method is simple and economical, but its accuracy and stability are poor. DC servo motor usually realizes open-loop control by directly setting the speed or position of the motor.

Closed-loop control introduces a feedback loop, the output of the system will be detected and fed back to the input, compared with the set value, and then the control system will adjust according to the comparison result to achieve the expected output. The closed-loop control has high precision and good stability, but the system is complex and the cost is high. The closed-loop control of DC servo motor is usually realized by feedback devices such as encoder and potentiometer.