Transient torque characteristics of stepper motor
Due to the inertia of the stepper motor, even if the idler runs one step, it will produce an over-shoot and oscillate back and forth between the overshoot and the under-shoot. After the attenuation, it will be at a fixed angle. This is the transient response characteristic of the stepper motor.
The figure below shows the transient characteristics of the stepper motor. The vertical axis takes the rotor movement angle and the horizontal axis takes the time. ΔT is the rise time, Δθ is the overshoot angle, and the time during which the rotor is free to rest to the set position (usually the time to reach the error range of 5% of the step angle) is called the setting time.
The shorter the settling time, the faster the speed. In order to speed up the operation of the mechanism and shorten the settling time, the damping (braking) of the stepping motor becomes important. Methods for shortening the settling time include changing friction or changing inertia driving.