stock application with IMH07M1 generates "speed feedback" error

[sgordon777]

Motor control workbench Version: 6.2.0

STM32CubeMX Version: 6.10.0

STM32CubeIDE Version: 1.14.0

Controler: NUCLEO64-STMG431RB

Driver: IMH07M1

Motor: rs2205: very simmilar spec to Bullrunning motor (7PP, 0.1ohm, 0.01mh, etc....)

 

Hi. I created a FOC app with my controller+driver+motor above.. When I try to start it, the motor spins up just fine, but I get a "speed feedback" error.

-This is a profiled motor

-The only changes I made to the application was to disable driver protection feature 

 

HW setup:

 

 

 

Motor config:

 

 

Error:

 

[Gael A]

Hello sgordon777,

Could you please tell us why you decided to remove the driver protection on the IHM07 ? If I recall correctly, there is no OverCurrent Protection on the IHM07, so the Driver Protection is the only feature protecting your board in case of overcurrent.

Concerning your Speed Feedback issue, I would at first glance recommend you to increase your PWM frequency since you are using a low-inductance motor.
If this does not fix it, then have a look at your currents and estimated speed. If they are too noisy, try reducing your PLL G2 gain, or play a bit with the Speed Kp & Ki gains.

[sgordon777]

Thanks for that...

 

-I disable the driver protection ffeature because it's given me nothing but problems both with this new IHM07  board and other hardware I've used like G431-ESC1. On this IHM07 board in particular, both in FOC and 6-step (I have 6-step working OK on this board) every single time I try to start the motor the fautl occurs even with the longest filter time-constant. I'll try to work this feature back in after I get the motor running, but I don't have much hope, and as I said I tuned 6-step completely without it(I keep a very close eye on the curent draw and heat from the chips)

 

-Regarding PID tuning... Doen't the speed feedback error mean that the issue was detected in the spinup (before PID loop starts)??

 

-Speed detection is accurate and very stable duinng the spin-up

 

-I tried 32000 and 40000 with no luck. Part of the problem is I don't know enoujgh about the sensorless FOC speed detection algorithm, can you refer me some docs on it?

[Gael A]

Hello sgordon777,

You can find information on the Speed Feedback error in the MCSDK's documentation : while in WorkBench -> Click on About -> Documentations -> Documentation -> User Manual -> Firmware errors. It explains when and why Speed Feedback errors occur. In your case, I believe it happens during the SWITCH_OVER state. Maybe increasing the range of the acceptable speed variance will do the trick, although you will have to check the stability yourself to see if it meets your needs.

 

Also, I have looked at your images again, and when checking your speed ramp, I believe the targeted torque may be a bit too high. The IHM07 output RMS current is limited to 1.4A (following datasheet), which is lower than what you input, so concerning the driver protection, the only thing I see is a start-up current ramp that would be too high.
If this does not fix it, then maybe the error given by the driver is not an overcurrent. However we currently have no solution for such behaviors (apart from removing the driver protection as you did). Maybe try to get an insight on what is happening from the range of possible driver errors ?