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Mark-S
Mark-S
Associate II
September 24, 2018
Question

Hello, I am evaluating the STEVAL-SPIN3201 with the ST-SPIN32F0and trying to achieve very low speed with high torque.

  • September 24, 2018
  • 3 replies
  • 1139 views

 I am using a 57BL90 motor with Halls, 90 watts, testing at 24vdc. I am using the ST workbench to specify all of the parameters then generate the *.h files which are downloaded using Keil. I am able to achieve good high speed motor control but very low speeds are very choppy and out of control. Even using torque mode only, the motor jumps and has a very uneven torque output. I will eventually be running the motor in position control mode commanding torque or speed from the position control loop. How can I get smooth torque and/or speed control of the motor at very low speeds??

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3 replies

T J
T J
Senior III
September 24, 2018

are you using timers to develop interrupts ?

the timers have a limited range, 16bit or 32bit. you may need to extend this range in software.

in the real world, timers like this are overflowing continually.

You may have to add another 16/32 bits to your timers and calculations

or else up the timer prescaler to 256 or 1024 or higher if you can.

If you need both Low speed and High speed then the timer extension may be required.

Mark-S
Mark-SAuthor
Associate II
October 3, 2018

Thanks very much for your response. I will check the timers, it makes sense this may be the issue but ultimately I will need the generate torque at zero speed when resisting an external force. Is anyone out there using torque mode at low/zero speed?

Laurent Ca...
Laurent Ca...
Senior III
June 22, 2021

The question has been moved from the section "Motor Control Hardware" to the "STM32 Motor Control" section (the question is about the STM32 MC SDK). 

Best regards

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