Closed-loop control vs traditional open-loop, a new choice for stepper motor drive

In industrial automation, stepper motors are widely used, such as industrial robots, 3D printers, computer hard drives, etc. The traditional stepper motor can control the angular position of the rotor without requiring a sensor to control the position. It is an open-loop control system. In this control method, the input of the stepper motor control pulse does not depend on the position of the rotor. Instead, it sends out its control pulses according to a fixed rule, and the stepper motor only relies on this series of established pulses to work. Most stepper motor-based motion systems operate in an open loop, thus providing a low-cost solution. In fact, the stepper system is the only motion technology that has position control capabilities without feedback. However, when the stepper motor drives the load in an open-loop manner, there is the potential for loss of synchronization between the command step and the actual step. .

Closed-loop control refers to a control relationship in which the controlled output returns to the input terminal as the control in a certain way and exerts a control influence on the input terminal. The closed-loop control of the stepper motor uses position feedback or speed feedback to determine the phase conversion suitable for the rotor position, closing the loop to verify/control out-of-step, detect motor stalling, and ensure greater effective torque output. , providing users with excellent accuracy and efficiency, which can not only achieve the performance of servo motors, but also have the low-price advantage of stepper motors, and can provide more economical solutions for motion control applications that have higher requirements for safety, reliability and accuracy. s Choice.