Page 1 of 3 123 LastLast
Results 1 to 10 of 21

Thread: Performance meter GPS software?

  1. #1
    Constant Bitrate
    Join Date
    Apr 2005
    Posts
    157

    Performance meter GPS software?

    Is there any GPS software that can give you performance estimates? Like 0-60 time, 1/4th time, estimated horsepower from mile per hour in 1/4th of a mile (i.e. 115 miles an hour in 1/4th of a mile would be around 450hp at 3800lb race weight)

    There are lots of non GPS units that due this, but they all have their flaws due to tire spin, and atmosphere conditions. So GPS would be perfect.

  2. #2
    FLAC evandude's Avatar
    Join Date
    Mar 2005
    Location
    Maine
    Posts
    937
    I'm not personally aware of any; but then again I've never looked. but the idea raises some issues such as update rate, and position accuracy. IIRC, GPS receivers for the PC only update once a second, and position accuracy seems to be on the order of several meters. Considering the amount of money some people spend to shave tenths of a second from their 1/4 mile time, an accuracy of only around 1 second doesn't seem real great.
    But don't take it from me! here's a quote from a real, live newbie:
    Quote Originally Posted by Viscouse
    I am learning buttloads just by searching on this forum. I've learned 2 big things so far: 1-it's been done before, and 2-if it hasn't, there is a way to do it.
    eegeek.net

  3. #3
    Constant Bitrate
    Join Date
    Apr 2005
    Posts
    157
    Quote Originally Posted by evandude View Post
    I'm not personally aware of any; but then again I've never looked. but the idea raises some issues such as update rate, and position accuracy. IIRC, GPS receivers for the PC only update once a second, and position accuracy seems to be on the order of several meters. Considering the amount of money some people spend to shave tenths of a second from their 1/4 mile time, an accuracy of only around 1 second doesn't seem real great.
    That would be an issue. I guess that is why the GPS standalone units that do this cost thousands.

  4. #4
    Maximum Bitrate v8 scimitar's Avatar
    Join Date
    Jan 2005
    Location
    Scotland
    Posts
    743
    The stuff you are on about has a lot more than GPS in them, in fact they probably use GPS very little and use it more as a sales pitch than anything else. The main part is the accelerometer. If you know the weight, G pulled and the length of time along with engine RPM and a few other things you can work out just about anything. So far as I know GPS is GPS whether its domestic or military that's why smart weapons have a + or - 5 meter accuracy.
    Visit my site V8 Scimitar

    SP13000, 300GB SATA HD, 1GB DDR. Opus 150, K301 screen, Cisco WIFI, AQmax GPS, RoadRunner and FreeDrive, Sony MEX-R5 head unit. 4 years installed and it just keeps running!

  5. #5
    Constant Bitrate
    Join Date
    Apr 2005
    Posts
    157
    Quote Originally Posted by v8 scimitar View Post
    The stuff you are on about has a lot more than GPS in them, in fact they probably use GPS very little and use it more as a sales pitch than anything else. The main part is the accelerometer. If you know the weight, G pulled and the length of time along with engine RPM and a few other things you can work out just about anything. So far as I know GPS is GPS whether its domestic or military that's why smart weapons have a + or - 5 meter accuracy.
    The unit I'm tailing about is not a accelerometer, it has just a GPS unit that size of a tool box. A accelerometer would need to be set up a level surface and would have sensors, this thing was just a box with an antenna.

    I read about it when car and driver did a test on a bunch of accelerometer performance meters against their GPS based unit.

    Our sophisticated VBOX system doesn’t use accelerometers, precisely to avoid this problem. Instead, the VBOX relies on the global-positioning system (GPS) to measure a vehicle’s motion. To work, the VBOX must be in communication with at least four of 24 GPS satellites orbiting the earth. As a vehicle travels down the test venue, there’s a minuscule shift in the arrival time of the radio signals that travel between the satellites and the VBOX’s antenna. By measuring this shift, the VBOX calculates speed, acceleration, and distance. Racelogic, the company that makes the VBOX, asserts that its devices are accurate to within 0.06 mph.

    They said it cost 30 grand..
    http://www.caranddriver.com/features...ters-work.html

    So it seems it compensates for the delay by using a mathematical algorithm of some sort. So, who do you need a 30 thousand dollar unit to do this? I would think software could do it just as well.

  6. #6
    Maximum Bitrate wi77iam's Avatar
    Join Date
    Jun 2003
    Location
    Chester Springs, PA
    Posts
    605
    Quote Originally Posted by v8 scimitar View Post
    So far as I know GPS is GPS whether its domestic or military that's why smart weapons have a + or - 5 meter accuracy.
    Differential GPS and WAAS greatly increase the accuracy - probably down to a couple meters. Military GPS using L1 and L2 encrypted signals has accuracy much less than +/- 5 feet. How do you think they put those smart bombs through a particular window or down a ventilation shaft?
    *******************************
    *******************************

  7. #7
    Raw Wave god_of_cpu's Avatar
    Join Date
    Jan 2004
    Location
    SilverSpring Maryland
    Posts
    2,960
    Quote Originally Posted by 96TransAm View Post
    The unit I'm tailing about is not a accelerometer, it has just a GPS unit that size of a tool box. A accelerometer would need to be set up a level surface and would have sensors, this thing was just a box with an antenna.

    I read about it when car and driver did a test on a bunch of accelerometer performance meters against their GPS based unit.




    They said it cost 30 grand..
    http://www.caranddriver.com/features...ters-work.html

    So it seems it compensates for the delay by using a mathematical algorithm of some sort. So, who do you need a 30 thousand dollar unit to do this? I would think software could do it just as well.
    It's not really a software issue. They must be using special hardware. A typical USB based GPS has an update rate of no more then 5 Hz, 1 Hz is probably typical. If you spend enough money, you can get special hardware that update alot faster like 30-50 Hz which is probably what they are using and why it costs 30 grand.
    StreetDeck.com Developer (I am Chuck)
    Get StreetDeck at http://www.streetdeck.com
    The Official StreetDeck Forums have moved, please visit us at http://www.streetdeck.com/forum for official support for Streetdeck.

  8. #8
    Constant Bitrate
    Join Date
    Apr 2005
    Posts
    157
    Interesting...So think we can start a GP on some?

  9. #9
    FLAC evandude's Avatar
    Join Date
    Mar 2005
    Location
    Maine
    Posts
    937
    In what little I've read about it, it seems one of the big limitations to accuracy and speed is the amount of number-crunching required. The GPS unit triangulates its position in 3 dimensions by doing a bunch of high-precision floating-point math on the signal strengths and directions from all the satellites.

    an example of the amount of number-crunching power it takes:
    http://www.dsprelated.com/showmessage/22833/1.php
    The theoretical limit is down to the integration time for the receiver,
    typically 1-10ms. If you want high dynamics, you need to update faster.
    For car racing, it's probably closer to 1ms.

    Most comercial receivers output 1 position per second because it takes
    some number crunching to compute the satellite positions and solve for
    the receiver position. This is purely a matter of computing power.

    Given a fast enough processor, 1000 positions per second is possible.
    I was running an automotive receiver IC (60MHz,32bit MIPS processor)
    at about 10 fixes per second, getting close to 100% CPU.
    based on a quick googling, it looks like a DSP chip of that speed is something like $25 in production quantities, and I would imagine a GPS system that used it would be a few hundred bucks at least, and for something in the range of 30-50Hz (3-5 times faster) I'd expect the price to rise exponentially, which seems to be the case based on the prices that have been tossed around.
    But don't take it from me! here's a quote from a real, live newbie:
    Quote Originally Posted by Viscouse
    I am learning buttloads just by searching on this forum. I've learned 2 big things so far: 1-it's been done before, and 2-if it hasn't, there is a way to do it.
    eegeek.net

  10. #10
    Constant Bitrate
    Join Date
    Apr 2005
    Posts
    157
    Well then, a modern high end CPU would be able to do it easy you would think. The unit that cost them 30 grand is about 5 years old now, CPUs have come a long way.

Page 1 of 3 123 LastLast

Similar Threads

  1. AUSSIES!!! GPS software for PDA
    By krbz in forum GPS
    Replies: 2
    Last Post: 05-26-2006, 06:47 PM
  2. GPS Software with personal P.O.I. Iguidance? Or?
    By claudioita in forum Software & Software Development
    Replies: 1
    Last Post: 08-17-2005, 03:19 AM
  3. GPS Software to use.
    By vxcarpc in forum GPS
    Replies: 3
    Last Post: 03-30-2005, 03:03 AM
  4. Best GPS software for carputer?
    By dazuck in forum GPS
    Replies: 13
    Last Post: 03-10-2005, 09:52 AM
  5. Wtb: Gps Software And Gps Mouse!!!!
    By HitmanZ in forum Classified Archive
    Replies: 2
    Last Post: 08-03-2004, 09:56 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •