Seized

DC Motor Stall Recovery Debug

Symptom

A jam stops the drive, which never restarts after the jam clears. The Circuit figure lists plant registers and bit fields.

Measured trace of the starter on the public case: the shaft reaches about 12,000 RPM, stops when the shaft jams at 149 ms, and after the jam clears at 269 ms it turns backwards at about 2,000 RPM to the end of the run

Circuit

Block diagram: U1, an STM32F4, reaches the U2 motor drive and its shaft over the bus at 0x50061000 and sends its log out of USART1 to a serial console; below it, the five drive registers the program uses with offset, access and units

Pass condition

The shaft holds within 900 RPM of the setpoint to the end of the run, and never runs more than 350 RPM over it. no jam in that band by 200 ms after a jam back in it within 120 ms of the jam clearing

Notes

The line controller writes the mRPM setpoint to 0x2000FF00. The load differs every run and may jam the shaft in the 480 ms run. Keep the MOTOR and DONE lines on USART1.

Related challenges

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