Start-up fails, but gets to appropriate speed.

[SpinKernel]

I have an issue where I keep getting a startup fault. But the motor gets up to the speed its commanded to. I don't have this issue with the demo (IMH07M1) board, but I do with my custom power stage.

The only way this would fail is if the pointer to the next phase is null, but it should exit this before it gets to the end of the phase Linked list... I'm starting my observer at stange 2, theres 5 phases... I'm very confused also why this would fail using one hardware and not another when both spin the motor and get up to speed.

Thanks!

[SpinKernel]

Finally got reliable startup.

Dropped the kP of the observer down to 250 and reduced torque gain by about 25% and moved the kp divisor from 2 - 256 and now it spins.

Thanks for listening.

[SpinKernel]

That day was a complete fluke. after rebooting the board, I haven't been able to reproduce the functioning closed loop control.

I have adjusted every gain, startup profile. I can get it to at least provide good feedback and reliably get speed feedback error. But i cannot get it to converge and run closed loop.

I'm going to open a new thread to discuss using the open loop controller (which has 0 documentation).

[ALedi.1]

do your currents I_A and I_B still look like this? and did you press "stop motor" at this point where the red line is or did the graph experience this shift on its own? It looks to me like the voltage of the OPAMP output of your current sense is experiencing shifts. check if one of the voltage divider resistors has bad soldering. try measuring the output voltage V_OUT of the two OPAMPs and check if the resistors R2, R3 , R4, R5 are all good and have reliable contact to the PCB

[SpinKernel]

It actually did that. That was when it tried to close the loop.

I fixed that by reducing my torque kP values.

I also fixed many of my feedback errors by starting the observer on the 3rd phase, so i can get it up to speed before it collects a bad speed values. But now I just get a speed error when it tries to switch to run. My speed at failure is about 1/2 of what it should be (looking at the buffer). I have tried a lot to get it up, so far none of the gain nobs i touch seems to affect it.

I had to switch to open loop. just to get the thing to stay spinning reliablyish.

[ALedi.1]

did you check the output voltage of the opamps for consistency? a speed feedback error can have a dozen reasons, when the sensorless algorithm/observer is not able to correctly assume speed, as it can be seen from the scope above (estimated speed is experiencing shifts) this could be caused by bad current sensing since the observer is using an electrical model of your motor to estimate the expected back EMF, and current is one of the input parameters of the model. as you can see, the obeserver needs accurate current reading to reconstruct the BEMF correctly. So first I would check if my current sensing is working, do this by checking the output voltage of the OPAMPs and the resistor of the actual soldered component on your PCB (not in the software)

[SpinKernel]

Well, the demo motor that came with the IHM07 kit works default settings (basically after running the profiler) But this motor the profiler won't profile and default settings def don't work. The current looks great if you see it on the scope, very little noise. When i see it try to close the loop i do see all of the phases just kinda go wonky like that plot.

Yes i have become very intimate with the observer, i have been digging into the code to see what i can do. Considering another motor works fine, I don't think its the driver.

Perhaps my driver will work better (we have custom boards coming) since the current sense is done a little different, maybe less noisy? But i don't see any noise.

[SpinKernel]

I have switched to open loop for now out of lack of time. Newer motor designs will have the space for halls, which will be used. Sensorless just isn't viable for our application it seems. Thank you all for listening to me ramble and for all the advice.