GPS Insight Blog » odometer readings

Apr 17 2011

Odometer Reading corrections fix historical and future mileage in GPS Insight!

Category: Administration,New Features,New Features,Odometer Accuracy — rdonat @ 5:46 pm

100% accurate odometer readings within GPS?

Yes, finally!

We recently completed significant changes to our handling of odometer readings across all types of GPS tracking devices.

Note the past 30 days’ mileage is off a bit between my two devices in the same vehicle — that shouldn’t be the case, but it’s trivially fixed:

2 devices are off by 16 miles

No GPS Device is ever 100% (except HD-3500′s since they get odometer from the J-1708).

But with an occasional adjustment/calibration, you can get everything back to 100%. Both historically AND moving forward.

The last time I adjusted my vehicle’s 2 devices’ odometer readings was April/June of 2010 — nearly a year ago.

Yesterday I took a picture of my odometer so I could datestamp/register that odometer reading:

Rob's odometer yesterday at 1:56 PM

I drove 24 miles today & when I stopped in my garage, it was 39720. [note that could be off by up to .9 miles since I don't have a tenths display on my odometer]

GPS Insight allows you to add “odometer waypoints” which can even be in the past (as is this one).

Here I look at the existing odometer reading and then easily add the waypoint of 39696 to adjust the “current” odometer to 39720 (+- .9):

Enter the vehicle admin page and adjust Rob and Rob 4000

Note that “Rob” has become inaccurate by 12 or so miles in a year of driving:

Rob before adjustment

Now it’s fixed:

Rob after ajustment

And “Rob 4000″ is off by 25 miles after a year since the last adjustment:

Rob 4000 before adjustment

And now it’s fixed (we always round to the closest number and 39719.6 is closer to 39720 than 39720.6):

Rob 4000 after adjustment

Now everything is “calibrated” between the 2 devices and my car.

The 12 & 25 miles of inaccuracy are “spread” out between all the trips taken since the last calibration entry, and the calibration factor will be used for future reporting and then adjusted to “reality” once another “odometer waypoint” is entered in the future.

We plan to utilize the Wright Express data feed which we receive for our customers’ vehicles in order to automate this as well for all our customers, when the data being entered at the pump is sensible. We will also make it easy to delete these adjustments if they are not wanted, or turn that functionality off at the account or vehicle level if the customer wants it turned off because their drivers aren’t entering good data.

In any case, this data is REALLY as good as it gets in the GPS Tracking industry. You won’t find more accurate mileages anywhere.

Even 20 or so of the “missing” miles for one of my vehicles is because I forgot to reinstall it after a trip until I drove home from the airport. That’s user error, not GPS Insight error… And if you know how to reconstruct reality, you can always enter multiple waypoints to ensure the proper mileage got assigned to the right days.

By the way, this isn’t terribly important for maintenance — but it IS IMPORTANT for companies who bill for mileage, bill their departments or drivers for mileage, or are just sticklers for detail and accuracy, as we are.

Why don’t other GPS companies go to this length to ensure accuracy going back over a year? Because most of them only give you 3 months or 90 days (maybe 6 months max) of historical data access. Remember we give you 5 years and more if you ask for it. All at no charge.

Give us a call with any questions on your odometers — not the most exciting topic, but it’s great to know that we get it right for you.

Rob.

Tags: Fleet Tracking, GPS Tracking, odometer accuracy, odometer readings, Vehicle Tracking

Comments (1)

Jul 25 2010

Our Odometer Readings are as accurate as you can get! (not very exciting but very important to get right…)

Category: competition,New Features,Odometer Accuracy — rdonat @ 1:26 pm

That seems like I’m stating the obvious, but GPS does not equal accurate odometer readings.

Many of our competitors don’t even give you that information — just the # of miles driven.

Here at GPS Insight, we have recently released a VERY ACCURATE odometer calibration mechanism to ensure that no matter what type of vehicle or GPS Tracking device you use, your odometer readings will be about 99.8% accurate. This is a big improvement from the typical 98% “best” we see with competitors.

If your vehicle drives 10,000 miles a quarter, we may be off 20 miles. They may be off 200! Even so, that’s not going to cause an engine blowout, but if you are billing or charging departments based on accurate mileage, GPS Insight will help you avoid the inevitable questions once GPS mileages are scrutinized.

A year and a half ago, we allowed our customers to enter multiple historical corrections, which is much better than the single “offset” which most companies provide.

Now we have improved this in 2 ways:

Offsets (corrections) are “spread out” historically to avoid spikes in mileage
Corrections are used going forward as a calibration to more accurately depict odometer readings so odometer corrections are much less necessary & can be done once or twice a year, vs. once or twice a month.

This was surprisingly a HUGE amount of work, which explains why none of the other providers we’ve seen have ever bothered to fix this fundamental flaw in GPS tracking devices.

Here’s why they’re not accurate, by the way:

GPS Tracking devices typically pull mileage from “GPS Interpolation” — since they know where a vehicle is at any point, they can compute the mileage between points. Our GPS-based odometer calculations take place 4 times a second, but they are still slightly off — typically 1-3% lower than reality. This is also because we are adding to mileage when a vehicle is in reverse, even though the odometer isn’t incrementing.

Some devices, such as our LD-3500, pull odometer readings as a function of data from the engine’s computer — but not the odometer reading itself. Again, this is typically 1-2% off, overstating mileage.

There are all sorts of nightmarish billing and leasing problems which we’ve heard about from our customers when odometer readings aren’t 100% (or at least 99.8%) within GPS Insight, so we made these changes. After a few weeks since the newest, now “calibrated” adjustment, my vehicle is within 1 mile of accuracy, which is partly due to the rounding on this report. I probably won’t need to adjust the odometer again all year as a result of these changes — here is what GPS Insight thinks my odometer is for each device, when my actual odometer reading is 35,482. By the way, some people claim GPS is MORE accurate, since tire pressure & size, as well as tire slippage can throw off an odometer. Good luck proving that one though. The reality is everyone goes by the odometer reading & we need to ensure we’re as close to that as possible.

off by 1 mile with 2 different types of device installed

Show historical odometer correction history:

Historical odometer corrections

Here is the new interface for viewing and editing historical odometer corrections, along with a really cool new graphing mechanism we’ll be using within the site going forward for other things:

New Odometer Graphing/Editing Interface

So, to summarize, just know that GPS Insight is working very hard to ensure your data is as accurate as humanly possible, given technical limitations which exist with GPS Tracking devices. By the way, the good news is that Heavy Duty Vehicles (J-1939/1708) using our 3500-HD have always had 100% accurate odometer readings since that is the only device available which gets real odometer readings from the engine.

Enough about Odometer Readings — I’m very glad this project is over — very important but not the most exciting thing in the world…

On to more interesting things now (like user-definable categories & attributes for vehicles, drivers, landmarks, users, stops, and trips)!

Rob.

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking, odometer improvements, odometer readings

Comments (2)

May 01 2010

NEW! Upload Vehicle Odometer & other detail updates via Spreadsheet!

Category: Ease of use,New Features,Odometer Accuracy — rdonat @ 1:41 pm

Since most of our GPS Insight Vehicle Tracking devices are slightly inaccurate when it comes to actual miles driven, we have made some recent changes to:

Make it easy to import corrections via Excel Spreadsheet from a Fleet Management System
Use these corrections to “calibrate” the device, taking them from 98-99% to 99.8-99.9% accurate

Vehicle odometer and/or label information can now be uploaded via spreadsheet to update the website. First, open the Spreadsheet Importer from the top of the website:

Next, select either Update Odometer Waypoints or Update Vehicle Labels, browse for, and click Upload Spreadsheet to load the file with vehicle information (such as vehicle label, licens plate, color, make, model, etc.):

The spreadsheet should contain the vehicle information to be updated, with one row per vehicle. If odometers are being updated, the Odometer readings and corresponding reading Timestamps should be in columns next to either the VIN, serial number, or vehicle label – as shown below. If vehicle labels are being updated, new values for Vehicle Label, Color, License, License Country, and License State can be in ordered columns next to either the VIN or serial number of the vehicle.

Note that the Timestamp allows you to update as of a particular time, so that even if the vehicle starts to drive after you take the reading, it will still make it accurate.

Uploading the spreadsheet will allow you to preview the import and match the correct column definitions to the spreadsheet’s columns. When complete, click on Preview the Import:

All rows of the spreadsheet and its data are then shown in the manner they will be imported. Green check marks indicate that the row will be imported. After verifying the information appears correctly, click on Proceed with Import:

Vehicle labels and odometer readings will then be instantly updated.
Very shortly, GPS Insight will introduce an automated “odometer factor” which will make future odometer readings much more accurate, based on historical adjustments.
For instance, a typical device odometer (with either an LD 3500 or GPSI-3900/4000) is off by 1-2% [typical, since GPS, and light duty OBD-II odometer readings are not 100% accurate]. After 500 miles, the device may show 490 or 510. If this is adjusted, the 2% adjustment factor is used moving forward, so that after the next 500 miles, the device will most likely show 999 or 1001. This feature will make odometer adjustments far less necessary. Only one or two reasonably spaced odometer adjustments is necessary to “calibrate” the device to the vehicle. Exceptional situations, such as a running vehicle being towed, or excessive backing up or start/stop may cause odometer readings to differ, but GPS Insight makes it easy to adjust those odometer readings to reality, and “allocates” the error to the prior miles in a way which avoids “jumpy” odometer adjustments.
Note that most other GPS tracking companies do not even track odometer reading – they only track absolute miles driven, which does not help with preventative maintenance schedules such as GPS Insight’s or 3rd party FMS software, which GPS Insight supports via API.

Using GPS Insight’s odometer readings, as well as our automated updates and “smart” calibration, you can ensure that your Preventative Maintenance (PM’s) will be done at just the right time, and that mileage billable will be accurate and accountable.

Rob.

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking, odometer factor, odometer readings, scheduled maintenance

Comments (1)