VESC-Tool 2.04: FW 5 >> A BIG STEP FORWARD

You can do this by shorting the phases to one another.

However, you need the tracking if you want regenerative power going to the battery. You also need the tracking if you don’t want your ESC FETs to reach star temperatures when you brake at anything but a very low speed.

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We had how many years where people used unsensored bldc? How did braking work there??? I mean it does work even without HFI or without sensors. Maybe not as smooth and accurate, but as long as the motor rotate it should be possible to create a decent brake.
Where am I wrong here? I don’t get it, sorry.

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@b264 how did you brake on your boards before HFI? Footbrake only?

Down to a speed x and then no more. Without bindings you can hop off your board at that speed.
Or the motor blocks at that speed, which people do not like.

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So unsensored would as well lose 100% brake force as soon as the rotation of the motor is below 5km/h, right?
I mean I understood that from the times before smart reverse that at 0km/h there is no brake force, but if I lose 100% already at 2-5km/h it’s enough speed to let me roll into an intersection. That’s not an issue if you can jump of the deck or footbrake, but in bindings that could be a bit tricky :sweat_smile:

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Mostly, but I also feel like older versions of the firmware had better braking at lower speeds. I was also using BLDC mode and Ackmaniac software before the HFI feature caused me to give up both.

I still like and prefer BLDC mode, but the absence of HFI means I exclusively set up FOC mode now.

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Like Frank mentioned, there was a block, or shorting the phases out, at extremely low speeds.

This causes other problems though, like for example when I roll down the ramp in my parking garage riding full brake the ESC will go from 30°C to 90°C in mere seconds and when I get to the bottom the throttle doesn’t work because it’s in thermal throttle mode

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Older implementations had a very rough braking behavoir at slow speed. Basically feels like shortening the phase wires. Now we are in the age of nearly perfect sensorless rotor tracking. Personally I use HFI on my boards now. Start of next year we will have even better solutions on the table.

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Yeah but with old hardware not :sob:

One last question:
So let’s assume I have a long straight road.
Setup sensored foc, smart reverse
I brake, sensors fail and I keep rolling at 5km/h with throttle in brake position.
Would smart reverse start to kick in at some point?

I don’t think it was ever answered what hardware will ASS use

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We can try to tweak it as good as possible to get the best out of old HW. But for best results some HW changes are needed.

We will see how it goes with the new features next year.
Could you please also answer the main question Frank :pray:

smart reverse would try to kick in, but you would see a lot of stutter and cogging. I guess you have two motors though and probably only one sensor would fail .

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I think the problem is that vesc can’t measure current if it shorts the mosfets for full braking, and if it can’t measure stuff it’s easy to blow all of them if they pass their ratings

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Set your sensors or openloop to shut off at a lower erpm and you will face this issue at 1km/hr instead of 5. My motors seem to work fine with 2000erpm and i’ve done some testing down to 1100erpm for about 90% launch success rate (as in smooth start and no faults or screeching). Beyond that only mechanical brakes can help you

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Just so people know, (cause i didn’t) FW5.02 is now officially released and available for download from the VESC tool.

According to Vedder the changes are:

  • Bidirectional current mode for VESC Remotes.
  • Motor temperature measurement fix on unity and stormcore.
  • IMU calibration improvements.
  • VESC Tool does not allow uploading firmware to all VESCs on the CAN-bus if they have different hardware versions.
  • Added LSM6DS3 IMU support.
  • Added MTPA support. See See: https://github.com/vedderb/bldc/pull/179
  • App PPM rework. See https://github.com/vedderb/bldc/pull/192
  • SWDPROG (blackmagic probe) improvements
  • App Balance updates. See https://github.com/vedderb/bldc/pull/193
  • Motor current now based on magnitude of both axes.
  • Initial VESC BMS support.
  • Hall sensor interpolation improvement.
  • Made hall sensor filter configurable.
  • Added locking time and ramp up time parameters to sensorless startup.
  • Initial VESC IO-board support.
  • Added hall sensor interpolation ERPM config option.
  • Use fast speed estimator for RPM limit.
  • Avoid accumulated rounding error when using PID position angle division.
  • Added UAVCAN raw throttle drive mode (current or duty cycle control).
  • Added MT6816 encoder support. See https://github.com/vedderb/bldc/pull/238
  • Added modulation-based D axis current controller gain scaling. Addresses https://github.com/vedderb/bldc/pull/220
  • Added PAS app. See: https://github.com/vedderb/bldc/pull/243
  • Added 100k CAN-baudrate.
  • Added 100k NTC temperature sensor support.

Not listed but other changes of interest are:

  • large rework to the duty cycle soft limit that was causing street-face in previous builds.
  • Added support for Stormcore 60D+ (with fixed second uart)
  • Added support for Cheap FOCer 2
  • Added support for new NRF chips
  • Spelling fix’s by @b264 :wink:

If Anyone know of any changes missed then let me know and i will add them.

It may be official now but use with caution.

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this.

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Thank you for the update and rundown

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Uh-oh another big update. Will I be finally able to use bluetooth connection with windows machine and OFFICIAL vesc-tool or do I still have to wait for someone to port it?

Sorry, I’m confused. Is this different than 5.1? Is this one the latest or is 5.1 the latest?