As a new control technology of stepper motor, the closed-loop stepper motor control is a high precision optical incremental encoder installed on the back axle of the traditional stepper motor So the driver can monitor the position of the motor shaft in real time, sampling the position information of the motor shaft 20000 times per second, which makes the driver can compensate the displacement deviation in real time and ensure the accurate positioning. Because the traditional open-loop stepper motor has no encoder to feed back the real-time Rotor position information, when the load changes suddenly, the motor will lose step, which will lead to the positioning error, and finally bring the huge loss to the user. Closed-loop stepper system is especially suitable for low rigid load cases, if using AC servo system, they have a common problem, is always to do compensation action. In order to get better rigidity, the AC servo system especially wants to work under high gain condition, which will easily lead to the AC servo motor position deviation, and the driver will correct the deviation by overshoot in the opposite direction This kind of air shock phenomenon is very common in the system, in which the static friction is obviously higher than the running friction. The solution is to reduce the gain, but the response speed and accuracy will be affected. The closed-loop step-by-step system can solve this problem perfectly. It takes advantage of the unique performance of stepper motor, its fixed in a fixed position, reducing vibration. This advantage is particularly applicable in the areas of nanotechnology, semiconductor manufacturing, vision systems and inkjet printing, as these manufacturing industries have high requirements for low vibration systems.
