## Statistical Data Analysis - Vehicle Drive Cycles

## Statistical Data Analysis - Vehicle Drive Cycles

(OP)

Hi Everyone,

I'm looking to get a little shove in the right direction. I have a massive amount of refuse truck data which includes such parameters as speed, gps location, fuel use, dump weight, idle time, etc.

What I would like to do is determine how similar two drive cycles are in order to see statistically significant fuel economy benefits between two different vehicles.

The data I have was collected while the trucks were in use for over a year of operation and was not a "controlled" experiment. As of right now I simply calculate a bunch of drive-cycle parameters for two different trucks and see how similar they are. However, I'd like to use actual statistics to prove that the datasets can in fact be fairly compared.

Please let me know if you have any ideas or statistical concepts I can look into.

Check out the attached excel table to see results.

Thanks,

Matt

I'm looking to get a little shove in the right direction. I have a massive amount of refuse truck data which includes such parameters as speed, gps location, fuel use, dump weight, idle time, etc.

What I would like to do is determine how similar two drive cycles are in order to see statistically significant fuel economy benefits between two different vehicles.

The data I have was collected while the trucks were in use for over a year of operation and was not a "controlled" experiment. As of right now I simply calculate a bunch of drive-cycle parameters for two different trucks and see how similar they are. However, I'd like to use actual statistics to prove that the datasets can in fact be fairly compared.

Please let me know if you have any ideas or statistical concepts I can look into.

Check out the attached excel table to see results.

Thanks,

Matt

## RE: Statistical Data Analysis - Vehicle Drive Cycles

Let's select one result - mpg. Run the descriptive stats on that for both trucks. You'd have 34 values for one; 53 for the other.

I would then be tempted to run a 2-sample t test. You're trying to find out is the mean value the same or not for the 2 trucks.

I would repeat this for tons per gallon, avg driving speed, etc.

I normally use MiniTab for my statistical analysis. Other pprograms are also available.

Hope this helps.

## RE: Statistical Data Analysis - Vehicle Drive Cycles

I don't see how you could do that analysis unless you have the actual fuel pump rate data or equivalent. Just having got a Prius, it's interesting to see how much your instanteous mileage fluctuates as a function of acceleration, road conditions, etc.

Just from my short experience with the Prius, it's clear to me that unless you have a detailed and accurate model of the driving of the truck w.r.t. gas consumption, anything other than a gross comparison would be hard to validate.

TTFN

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## RE: Statistical Data Analysis - Vehicle Drive Cycles

IRstuff - The raw data is recorded directly from the CAN bus at 1hz. I simply added up the fuel rate L/s at each second to come up with a total fuel usage. Agreed, it's not a controlled experiment which makes comparisons difficult.

Right now, all of my statistics are derived from summing each channel second by second, a gross calculation. Alternatively, I could perform statistics by day, using mpg, avg mph, drive%, etc for each day.... however, then each day get's equal weight ignoring the difference between a day the truck traveled 20 miles and a day it traveled 3 miles. Make sense?

## RE: Statistical Data Analysis - Vehicle Drive Cycles

TTFN

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## RE: Statistical Data Analysis - Vehicle Drive Cycles

I don't know whether you can accuont for that or if it is just a noise factor.

Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

## RE: Statistical Data Analysis - Vehicle Drive Cycles

After deciding on an index for your data (or parts of the data) you can use a statistical correlation measure like http://en.wikipedia.org/wiki/Cross-correlation to measure similarities and differences in the data.

If the data is unique and your index you come up with is unique ( of course if you decide to do it like this) then be sure to publish the results (if your company is alright with this)

Fe

## RE: Statistical Data Analysis - Vehicle Drive Cycles

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Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

## RE: Statistical Data Analysis - Vehicle Drive Cycles

I'll let you know how it pans out.

-Matt