Have the range calculation consider elevation

[michael]

The nav system knows the distances to be travelled between waypoints, but the digital maps can include elevation data as we'll.

Ford, please include elevation changes into your calculations. The first level would be to at least consider elevation differences between charging spots. A higher level of sophistication would check the entire route to make sure you won't run out of energy climbing an enroute hill. An even higher level of sophistication would be to let the mileage reserve calculation consider when the car is climbing or descending.

Lifting a 4000 lb car 1000 feet uses over 1.5 kWh. Assuming 80% efficiency and 20 kWh usable, that's over 9%of the battery. A 3000 foot climb would be over a quarter of the battery.

Yes, you reclaim much of that energy heading down the other side but not if you don't make it to the top...

 

[unplugged]

Ford, please include elevation changes into your calculations.

Good point, Michael. I go to my parents house and rise relatively slowly over 60 miles to 1500 feet. The difference is that I get about 75 miles range there versus about nearly 100 on the way back. If elevation (negative and positive) were taken into account, the range accuracy would be far greater.

 

[v_traveller]

I believe this was the subject of another post, where I replied that we might be stuck with an inaccurate range estimation due to patents that might be out there. Ford would have to come to some agreement with the patent owner (i.e. purchase, license, or ???) to provide us better range estimates using external sensors, such as an "elevation sensor".

I'm not a patent attorney, so please take this with a grain of salt, but here is one patent application that seems to lay claim to what is needed to collect and integrate, for example, elevation sensor data (i.e. GPS receiver), climate data, pretty much any other external data to provide accurate range estimates:

http://www.google.com/patents/EP2275317A1?cl=en

Here is an excerpt of what is being claimed:

"A system embedded in a vehicle, comprising:
a plurality of inputs including one or more of hard coded data, data from sensors on the vehicle, data from external sensors, user coded data, data received from remote databases, data received from broadcast data steams or data that has been accumulated or combinations thereof that provide information regarding one or more of vehicle speed, motor rpm, motor torque, battery voltage, battery current, and battery charge level; a processor unit connected to the plurality of inputs, wherein the processing unit calculates, from the processor inputs, an expected vehicle range as an output;"


If the patent is granted, I believe anyone implementing such a range calculator would be infringing on it, so long as it conceived after July 17, 2009.

If anyone can prove that such a range calculator was invented or implemented prior to July 17, 2009, I believe this patent application could be denied. Meanwhile I think we're stuck with a GOM. Another post indicates that Tesla might be in the same boat too. So I'm wondering.... are there any EVs out there with accurate range calculation that uses GPS data and known elevation data along a predetermined route?

 

[michael]

Yes, good point. Looks like those people are claiming to own the idea of including elevation, but I think the doctrine of "you can't patent something that's obvious to someone skilled in the art" would invalidate those parts of the patent. It's obvious to everyone who drives that elevation change influences energy use.

It is a shame that the patent system so often stifles good engineering.

And by the way...aircraft have long used altitude change as part of the fuel consumption and range calculation. So there's probably the possibility to claim public domain prior art to invalidate the claim as well.

 

[WattsUp]

One could probably get around this patent by creating a system that can retrieve (from a database of road-surface orientations, not elevations) the average incline or decline at all points along the route, and uses THAT information to compute the required power consumption. Technically, the algorithm would not be using the elevation information, just the road surface information. Mwu-ha-hA-HA.

Crap, I should probably patent this idea.