Stepper motor traditional stepper motor in the receiving to push a certain number of pulse command will move, the pulse interval related. Stepping apparatus is considered to be open loop system, due to their short reaction mechanism to verify whether has reached the target bearing. Servo motor will move when the received command signal from a control device. Compared with the open-loop operation system of step motor, servo motor is a closed loop system, built-in encoder can one after another and manipulation of the communication, make any necessary adjustments to ensure to reach the target bearing. Within the system of step motor, motor torque is not enough to overcome the load if available, the motor will be suspended or across one or more of the pulse, then arrive at the required location and the practice of produce differences between bearing. To prevent this kind of condition, stepper motor general size is too big, in order to make sure the worst condition between the load torque and motor torque available there is a big gap. But to choose large motors. After increase encoder and run off in the form of closed loop, stepper motor system can be implemented as servo motor bearing monitoring and control. Off in the form of closed loop stepper motor operation is the most direct way to compare steps should arrive according to the theory of bearing, and according to the encoder to practice orientation. If there are differences between goal orientation and practice orientation, the manipulation of the device start to proofread. Although the above method is reactive, in move check after the completion of the orientation of the machine, but closed loop stepper device can also have the difference between monitoring bearing reaction steps and encoder. After a succession of reaction, can increase the pulse rate, temporarily increase or adjust the current stepper Angle to complete real-time compensation. Off in the form of closed loop operation of stepping motor and the third way to choose sinusoidal commutation. If the rotor and the stator magnetic field does not have correct alignment, the encoder will adjust the motor current, make it match with the mobile or stick to load the required torque completely. Due to the use in after operation to control torque motor current, so the form is sometimes referred to as servo control. Off in the form of servo control, step motor is basically like a high number of servo motor, but there is no traditional stepper motor's noise and resonance, supply more stable movement and accurate control. Because the current is dynamic, not as stable as the traditional stepping motor, thus largely prevent the electrical heating problem. Closed-loop stepper motor eliminates the traditional open-loop step system of many shortcomings, make its function are similar to servo motor. But in need high speed, high speed high torque load or process change in use, the function of the servo motor closed-loop stepper motor and more.
