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Accelerometer I dea Question — Parallax Forums

Accelerometer I dea Question

ArchiverArchiver Posts: 46,084
edited 2002-01-21 03:04 in General Discussion
I am considering making a device that can measure 0-60 times, 1/4
mile times, etc for automobiles. This is going to be for my senior
project in electrical engineering. I am looking at the ADXL202
accelerometer from analog devices, and was considering using the
basic stamp. I am not sure if this combination will provide me with
the data I need. I was condiering just dumping the data to storage
and processing it later on. If anybody has and comments or ideas
please let me know.

Thanks

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 00:31
    Analog Devices web site has a relevant Techical Note: Using the
    ADXL202/ADXL210 with the Parallax Basic Stamp Module to speed algorithm
    development. Also, see the device application notes for ideas regarding
    calibration and filtering to minimize tilt sensitivity and optimize
    linear acceleration sensitivity. The cool thing about this approach is
    that it uses pulse width modulation, which doesn't require an A/D
    converter chip.

    Denni


    Original Message
    From: mhsneon [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=-m1bW87iMg6ZYXBRaHGENUN0SpWWmNPDzxpREBaaXT9HQWRGWuf5F1t455flKNXDzkhFaBwgs-g8Ve35]mhsneon@y...[/url
    Sent: Saturday, January 19, 2002 4:19 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Accelerometer I dea Question


    I am considering making a device that can measure 0-60 times, 1/4
    mile times, etc for automobiles. This is going to be for my senior
    project in electrical engineering. I am looking at the ADXL202
    accelerometer from analog devices, and was considering using the
    basic stamp. I am not sure if this combination will provide me with
    the data I need. I was condiering just dumping the data to storage
    and processing it later on. If anybody has and comments or ideas
    please let me know.

    Thanks


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  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 04:57
    Does anyone know of an accelerometer that would measure from 0 to 5 G? The
    ADXL202 only measures up to 2G.

    Hank


    Original Message
    From: "Dennis P. O'Leary" <doleary@h...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, January 19, 2002 7:31 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Accelerometer I dea Question


    > Analog Devices web site has a relevant Techical Note: Using the
    > ADXL202/ADXL210 with the Parallax Basic Stamp Module to speed algorithm
    > development. Also, see the device application notes for ideas regarding
    > calibration and filtering to minimize tilt sensitivity and optimize
    > linear acceleration sensitivity. The cool thing about this approach is
    > that it uses pulse width modulation, which doesn't require an A/D
    > converter chip.
    >
    > Denni
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 15:19
    Check

    http://www.analog.com/technology/mems/accelerometers/designTools/selec
    tionGuides/products.html

    at analog devices. They have a range of accelerometers. XL105 has a
    +/- 5g range

    --- In basicstamps@y..., "rcvehicles" <rcvehicles@y...> wrote:
    > Does anyone know of an accelerometer that would measure from 0 to 5
    G? The ADXL202 only measures up to 2G.
    >
    > Hank
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 15:49
    I am trying the same thing but for my recumbent bicycle. Having a bit
    of studying to do to trick the stamp into performing the math. I
    don't have a floting point coprosser which would make it easier I
    think. I am trying to register grade of climb and decent as well as
    acceleration around tight fast turns. Will keep you posted of any
    breakthroughs.

    --- In basicstamps@y..., "mhsneon" <mhsneon@y...> wrote:
    > I am considering making a device that can measure 0-60 times, 1/4
    > mile times, etc for automobiles. This is going to be for my senior
    > project in electrical engineering. I am looking at the ADXL202
    > accelerometer from analog devices, and was considering using the
    > basic stamp. I am not sure if this combination will provide me
    with
    > the data I need. I was condiering just dumping the data to storage
    > and processing it later on. If anybody has and comments or ideas
    > please let me know.
    >
    > Thanks
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 19:30
    Also check out a commercial product called a G-Tech pro. I believe it is what
    you are building. Also Top fuel cars don't pull 5 g's.


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 22:47
    At 2:30 PM -0500 on 1/20/02, moretraction@a... wrote
    >Also check out a commercial product called a G-Tech pro. I believe it is what
    >you are building. Also Top fuel cars don't pull 5 g's.
    >

    A fast tight turn on a WELL BANKED curve could easily exceed
    the lower 2 g limit.

    Without banking you'll do well to approach 1 g.

    How can you differentiate an incline and an acceleration? Somehow you
    will need to reference a 'real' horizon like a gyro? In a totally
    closed system, you CAN'T separate the effects of gravity and 'real'
    acceleration. My uncle Al told me this ;-)
    --

    .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    \ / \ / \ N / \ C / \ S / \ S / \ M / \ / \ /
    `-' `-' `-' `-' `-' `-' `-' `-' `-'
    Chuck Britton Education is what is left when
    britton@n... you have forgotten everything
    North Carolina School of Science & Math you learned in school.
    (919) 286-3366 x224 Albert Einstein, 1936
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-20 23:33
    >Also check out a commercial product called a G-Tech pro. I believe it is what
    >you are building. Also Top fuel cars don't pull 5 g's.

    They do when they crash.
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-21 02:41
    Yes, you have to be airborne to reach 5-10 g's. I met an aerobatic
    pilot who said he could routinely pull 8 g's without wearing a g suit.
    He later developed a severe inner ear (balance) problem and is now
    grounded.

    Dennis
    Prof & Director
    USC Center for Balance Disorders
    LA CA USA

    Original Message
    From: moretraction@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=oSumZFspbk_BJo6Kt-YvJR76AxsH1a5O21k322eqRg1Tpx4ZwWTYf5n1HqqBuwcTeFgzG-VityjlZhxb]moretraction@a...[/url
    Sent: Sunday, January 20, 2002 11:30 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Accelerometer I dea Question


    Also check out a commercial product called a G-Tech pro. I believe it is
    what
    you are building. Also Top fuel cars don't pull 5 g's.
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-21 02:48
    Chuck is correct. An independent angular sensor is necessary to monitor
    tilt, and then subtract the gravitational component of the tilt from the
    output of the linear sensor to get 'pure' linear acceleration. Chuck's
    uncle Al explained this in "The Evolution of Physics", Einstein and
    Infeld, published in 1936.
    Dennis

    Original Message
    From: Chuck Britton [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Sb5JTUgiKHvawOzVi7FpVhIdZkJ7lJk8z9l36QnkxCgK-nK2SykoAYBRh2jomdGrZT_yxNULAZRnZw7vRXSs]cvbritton@t...[/url
    Sent: Sunday, January 20, 2002 2:48 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Accelerometer I dea Question

    How can you differentiate an incline and an acceleration? Somehow you
    will need to reference a 'real' horizon like a gyro? In a totally
    closed system, you CAN'T separate the effects of gravity and 'real'
    acceleration. My uncle Al told me this ;-)
    --

    .-. .-. .-. .-. .-. .-. .-. .-. .-.
    .-
    \ / \ / \ N / \ C / \ S / \ S / \ M / \ / \
    /
    `-' `-' `-' `-' `-' `-' `-' `-'
    `-'
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-21 03:02
    Top fuel cars don't pull 5 g's.

    Ditto that. Steve Irwin, aka "The Crocodile Hunter" seems like a pretty
    tough guy, and he passed out cold in the back seat of a jet trainer during a
    maneuver that pulled something like 3 g's.
    I want to see the device this project is intended for...

    BTW, I once piloted a TAFC running a nitro mix during a test blast. What
    forces may I have been subjected to that crazy day? (building it was more
    fun!)

    CL
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-21 03:04
    A fast tight turn on a WELL BANKED curve could easily exceed
    the lower 2 g limit.

    Without banking you'll do well to approach 1 g.

    I take it these are not absolute measurements........?
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