Wheel angular velocity

[PKersting]

Wouldn't it be more suitable to use angular velocity (rad/s) instead of rotational velocity in km/h for the vehicle speed?
see https://github.com/COVESA/vehicle_signal_specification/blob/master/spec/Chassis/Wheel.vspec

[erikbosch]

First, sorry that there have not been any follow up on this one, we have not monitored the discussion tab regularly.

But back to wheel speed - the topic have been mentioned before. My personal view is that there might be scenarios where "wheel surface speed" is useful, like if you actually want to calculate Vehicle.Speed based on average wheel speed, or that you want to compare surface speed as part of TPMS system without sensors and possibly different size of the tires/wheels. On the other hand, in some cases the wheel road speed does not matter, and/or the vehicle assumes that all wheels have the same size. In some internal systems maybe you do not even need rotational speed in degrees/s or rad/s, it is maybe sufficient to have a tick counter or a tick/second value.

Anyhow, I see two possible ways forward

Refactor current signal to use rad/s (or degrees/s) as unit

Fully OK if no-one needs the existing unit. Best way forward is to create a Pull Request as we then would review it so that participants have the possibility to object to the refactoring. If we are to use rad/s as unit we will need to update the unit file as we as of today only supports degrees/s

Add a new signal and possibly deprecate the old one

We could create a new signal Wheel.RotationalSpeed and at least for now keep the old one. If we assume no one needs the old signal we could mark it as deprecated and possibly remove it later. The advantage with this approach is that we avoid changing meaning of the existing signal which always is a bit risky, as people using/integrating VSS may not realize that description/semantic of signal has changed, so this is the preferred method as I see it.

Feel free to create a Pull Request and then we can continue the discussion from there

[erikbosch]

Discussed in #678 as well. To bad a link is not created automatically from discussion to issue when a discussion is mentioned in an issue

[erikbosch]

Now we have a degree/s signal, see #726. Closing this discussion, reopen if needed