In-vehicle calculation conventions

[tguild]

For some assessments it is far more efficient and practical to perform calculations on the vehicle edge. It may be too onerous or costly to send a number of data points at a high frequency to the cloud when an edge assessment would be far better and to merely send the results.

As an example for evaluating 12V battery and alternator on a combustion vehicle, voltage from accessory, crank and first couple minutes after the vehicle starts at 100ms would require a considerable number of data points to be sent instead of two binary ones saying the battery and alternator are ok or not.

We should be able to express fundamental types of calculations that can be performed on the vehicle and result to send to the cloud.

[tguild]

https://en.wikipedia.org/wiki/Sampling_(signal_processing) describes notations for simple calculation representations and sampling

[tguild]

Results for some calculations to be performed in-vehicle could be assigned a VSS signal as a convenience.

The algorithm to produce the resulting value may vary by implementation, producing more accurate data or perhaps customized for a given vehicle's features/capabilities. For example there could be a defined, established common algorithm for calculating the correction factor (CF) for EV range prediction as a baseline but an entity can come up with a more accurate calculation for a given vehicle architecture taking advantage of additional sensor data.

[tguild]

The same issue has been raised and being followed in VSS repo

COVESA/vehicle_signal_specification#738