Industrial Control Summary: When a stepper motor driver is powered off, it is in a certain phase. If the phase is different when power is restored, the motor will "jitter". To eliminate the jitter, the phase at the time of power failure must be memorized. The stepper motor operates in 8 steps. If it stops at step 4, the board is powered off, and after power is restored, if the first step is started directly from position 4, a skipped step will occur. If the system remembers that it is currently in step 4, it can correctly issue commands to proceed to step 5 or step 3.
Most stepper motor drivers do not have a power-off phase memory function, especially stepper drivers that use common dedicated ICs. After the dedicated IC is powered on, the reset signal of the reset pin will reset the motor phase to the initial value, and power-on jitter is unavoidable.
Even with an absolute value servo motor, it still needs to be judged and corrected, which can also be regarded as jitter. Or strictly speaking, there is no motor that does not jitter when powered on.
The key question is how much this jitter affects your application? Ideally, you should record the absolute stop coordinates, reset the system after powering on to check the origin, and then run to the absolute coordinates before the power failure to resume operation.
