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zombieverter irratic torque demand in VCM CAN message
Posted: Wed May 07, 2025 8:37 pm
by mattes
Have the zombieverter hooked up to a 2020 Leaf inverter/PDM 110kw stack, together with leaf batterie.
Started scanning the CAN log traces from those runs and noticed this 'weird' series of torque demands sent by the VCM (zombieverter), when I apply the throttle. It looks weird to me. Maybe this is normal? Dont know, I am just new to all this. But I don't see that pattern with the original Leaf OEM VCU.
Do I have some misconfigured that contributes to this behavior? What am i missing in the zombie setup?
I did multiple runs and see this everytime after start, when I apply the throttle.
The first initial torque request by the VCM is 511Nm (isn't that max torque or more?).
The second 5Nm seems to be the value from the throttle, and the third is again 511Nm followed by another 5Nm
The irratic 511Nm seems to be sent all the way until max throttle is reached.
Here my
param.json and a
savvycan trace.

Re: zombieverter irratic torque demand in VCM CAN message
Posted: Thu May 08, 2025 5:00 am
by mattes
I might have found what was bugging my setup.
The zombieVerter parameter "throtramp" was set to 100. Such setting seems to spike the throttle torque demand.
Not sure how it got into my configuration set. some kind of default? Not sure, but I certainly did not touch that.
Anyhow here are 2 screenshots showcasing the Zombie VCM torque demand request CAN message for throtramp 100% and throtramp 10% configuration

Re: zombieverter irratic torque demand in VCM CAN message
Posted: Thu May 08, 2025 11:09 am
by tom91
mattes wrote: ↑Thu May 08, 2025 5:00 am
Not sure how it got into my configuration set
It was set to a 100% as default for older firmware. Latest forces it to 1 I believe.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 3:21 pm
by Rustybkts
I was about to start a new thread titled Uncontrolled throttle with Zombie on Leaf inverter but saw this one.
Initial testing using version 2.20 seemed OK with throttle control but lacks power in reverse which is already known and I assume will be sorted on the next update.
Since doing other testing with a test version 2.31TH I find that when increasing speed over around 10mph, the drive goes to full power spinning the wheels! Scary on my short drive!!!
I have loaded the latest gold update version 2.22a but no difference
Have attached CAN logs with the Ignition on in neutral and full accelerator pedal and another CAN log with the car in FWD selected and throttle gently pressed past 10mph until the revs are uncontrolled. Parameter list also attached.
I have checked the accelerator pot volts and they are smooth from minimum to maximum without any jumps.
Any assistance would be appreciated on this as it has already snapped the torque bracket on the drive unit which is now beefed up.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 3:38 pm
by tom91
Please generate logs of Potnom
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 3:39 pm
by tom91
To start
"throtramprpm": 1000 set this back to 20000rpm. This disables throttle ramping.
The rest looks pretty standard if you say the throttle values look normal when plotting.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 3:54 pm
by Rustybkts
Not sure how to save a plot and its easier to take a pic of the plot.
Pot volts is Red and Potnom is Blue. Due to the immediate increase in rpm, the vertical drop on the red trace is me taking my foot off the pedal.
You can see the spike on the Potnom trace.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 3:57 pm
by tom91
Is this after making the change as requested?
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 4:04 pm
by Rustybkts
No, just made the change and it seems OK now. That is scary though.
What is that parameter used for.
I am testing with the wheels in the air so it's not a proper test until I can go on the road.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 4:06 pm
by tom91
Rustybkts wrote: ↑Sat May 17, 2025 4:04 pm
What is that parameter used for.
tom91 wrote: ↑Sat May 17, 2025 3:39 pm
"throtramprpm": 1000 set this back to 20000rpm. This disables throttle ramping.
And can wreak havoc in the various places where the throttle can be ramped. Will likely move to remove this in a future release.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 4:15 pm
by Rustybkts
My project only seems to require the reverse torque increase to be added to the gold version although I may go back and try v2.31TH as that had all the functionality apart from the request HV input I will us with an Orion BMS controlled Chademo.
I note on another thread
viewtopic.php?p=82601#p82601 that others are having contactor control problems but I have not seen this at all.
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Sat May 17, 2025 4:47 pm
by tom91
Have now removed the throtramprpm as this is not really something being used in the VCU
https://github.com/damienmaguire/Stm32- ... 95998aa659
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Wed May 21, 2025 4:54 pm
by mattes
I just curious, what was/is the intent of ramping up the throttle reading?
quicker pedal response?
Re: zombieverter irratic torque demand in VCM CAN message
Posted: Wed May 21, 2025 5:09 pm
by tom91
mattes wrote: ↑Wed May 21, 2025 4:54 pm
I just curious, what was/is the intent of ramping up the throttle reading?
quicker pedal response?
Not how it works. The throtramp limits how quickly in percentage the throttle can increase per loop of 10ms. This will dampen all sorts of limits and sudden pedal inputs.
The throtramprpm would be the rpm at which this gets dis-regarded, no one was running this on zombie its carried over from OI inverter boards. It no longer works so will be removed.