Step servo/Closed-loop stepper motor VS AC servo motor
AC Servo motors are respected and relished by current engineers who are obsessed with the closed-loop control of servomotors and are intoxicated with the advantages of high response, high speed, and high accuracy. However, AC servo motors also have the following defects that are unavoidable:
1. Can't stand still: Due to adopting closed-loop control, the structure of the AC servo motor and the features of the motor determine that the servo motor can not be absolutely still when it is stopped. The AC servo motor is always in positive and negative condition when the load disturbance is small or the parameter of the servo motor is well debugged. Fluctuation between 1 pulse (can be observed by the servo drive on the value of the encoder position, it has been fluctuating between positive and negative 1). This is a factor that affects accuracy in image processing applications.
2. Overshoot: When moving from high speed to low speed or stationary, it will inevitably overshoot a certain distance and then correct it back. When the controller sends a pulse to the AC servo motor, which usually does not take one pulse, but takes 3 pulses and then backs off 2 pulses. This is absolutely fatal for overshoot situations where those pulses require a pulsed motion.
3. Complex debugging: There are hundreds of parameters in the servo drive and hundreds of pages of instructions for use; this also brings a lot of work for after-sales service and maintenance.
Stepping servo/Closed-loop stepper motors solve these problems perfectly.
Since the Stepping servo/closed-loop stepper motor is not simply a stepper motor with an encoder, it is designed and developed according to the working principle of AC servo motor system. It uses a 32-bit DSP as the main processor to ensure the high response and high speed of the whole system. It can adjust the current of the motor every 25 microseconds.
First, the Stepping servo/closed-loop stepper motor is a stepping motor with encoder, that means the main feature is same as stepping motor. when the motor is standstill status, the motor is absolutely standstill.
Second . the Stepping servo /Closed-loop stepper motors do not overshoot because they combine the features of a stepper motor and AC servo control (because stepper motors do not overshoot)
Third. It is very simple to debug and use. It only needs to adjust the position of the three potentiometers of the driver. It can be used not only by equipment manufacturers, but also by equipment manufacturers. The user's requirements are extremely low.
Fourth, the drive uses true sine wave, vector and filter methods to control the current, the minimum speed can be controlled at 0.2 rpm, and the motor runs very smoothly and stably.