I was mulling over the idea of having telemetry and other racing-oriented data displayed on the touchscreen and wondered if the MS has any accelerometers on board that might be tapped into for such a thing.
yes, it has accelerometer to determine when to light break lights during regenerative deceleration...
however I have no idea how to use it for other purposes.
We don't know that accelerometers are what trigger the brake lights, that was just an assumption.
It is also possible (likely?) that the brake lights go on at some preset level of regen and there are no accelerometers on board.
I have to think that using accelerometers to trigger the brake lights would be a bit of overengineering. I mean, speed + pedal position = brake light on/off should yield a pretty easy algorithm to control the brake lights.
A semiconductor 3-axis accelerometer cost less than a buck. The info from the device can be delivered a long with all the other telemetry from the power train and the battery system. It would make good engineering since to include several of these in the car and use these along with pedal position to light the brake lights.
Why wouldn't the car direclty compute the current acceleration:
( V(now) - V(now-dt) ) / dt
To many variables so not accurate enough sia
accelerometers are typically used to trigger airbag deployment, but I don't think you can use those for your telemetry data.
But the only variables to compute acceleration are speed and time.
Time is super accurate.
Are you saying that the instantaneous speed is not known accurately?
Accelerometers are used to trigger air bags.
Accelerometers and gyros are used in the anti-lock brakes (ABS) system and traction control system to help determine if wheel speeds are consistent with body rates and if not, then there might be slipping and sliding that needs to be "adjusted."
Automobile grade accelerometers and gyros are probably MEMS devices.
MS has full inertial navigation to back up GPS. That is why your car position updates on the map when you drive through a tunnel.
Not so naive... Speed is known - but direction is not necessarily known. Acceleration is change of the velocity vector -not the speed (scalar) - if direction is changing but not speed, you still have acceleration.
What locks up the seat belts during hard acceleration or heavy braking?
Sia one variable that is not in your equation is traction. That will under certain conditions affect the result.