×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

*
*
*
*

Thanks. We have received your request and will respond promptly.

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Statistical Data Analysis - Vehicle Drive Cycles

thread962-302794

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

RE: Statistical Data Analysis - Vehicle Drive Cycles

What you've presented is summary data.  I'm guessing you have the actual data by day and this is what you ought to use.

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

You make calculations on the "Driving Fuel Economy," but it's unclear whether that's simply a gross calculation, or something involved with more instantaneous fuel usage measurements.

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

FAQ731-376: Eng-Tips.com Forum Policies
Chinese prisoner wins Nobel Peace Prize

RE: Statistical Data Analysis - Vehicle Drive Cycles

(OP)
Magoo - thanks, I think the t-test for each drive-cycle parameter would give me a good idea if the datasets can be compared.

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

You can come up with your own index first. Maybe something that is not exactly frequency based but along the those lines. Could use for example 1/time where time is the idle time, or distance time ect. The other axes will be the fuel consumption or other relative measure you want to compare.
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)

cheers

peace
Fe

RE: Statistical Data Analysis - Vehicle Drive Cycles

(OP)
Guys - Thanks so much, I'm going to research your suggestions and give them a try with my data.

I'll let you know how it pans out.

-Matt

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login

Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close