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Using Accelerometer Data — Parallax Forums

Using Accelerometer Data

SchoenSchoen Posts: 1
edited 2007-04-05 00:54 in Learn with BlocklyProp
Hello,

My name is Tim Schoenmakers and I am a student commercial engineering at the university of Antwerp. I have to build a water rocket which has to have an accelerometer that registers accelerations in three axes. The idea is to use that data to integrate it to obtain speed and integrate it twice to calculate the position of the rocket throughout the flight.

The accelerometer we use is a "±1.5g - 6g Three Axis Low-g Micromachined Accelerometer". Obtaining the data should not be a problem either through a RF-link we will have the output on a computer nearby.

The output comes every 0,1 second and is translated into a text file

Example:
Rocket
X=378
Y=344
Z=356

However, because the rockets is launched under 45°, it tilts during its parabolic flight and rotates a little around it's own axis because of aerodynamic imperfections, I don't know how we have·to interpret the data. Is it possible to integrate these data when the accelerometer rotates?

Kind Regards,

Tim

Comments

  • edited 2007-03-13 21:53
    Hi Tim,

    I would start by looking up Inertial Measurement Unit on Wikipedia. The main feature your setup currently needs is a 3-axis gyro to keep track of rotation. Combined with the acceleration data, there may be enough data to rebuild the trajectory. Also do a search for gyro on www.analog.com.

    As a side note, check out Chapter 6, Activity #5 in Smart Sensors and Applications. Instead transmitting the measurements by radio, the BASIC Stamp 2 saves the values in its EEPROM memory.

    Smart Sensors and Applications product page:
    http://www.parallax.com/detail.asp?product_id=28029

    Smart Sensors and Applications PDF:
    http://www.parallax.com/dl/docs/prod/sic/SmartSensors-v1.0.pdf

    Andy

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Andy Lindsay

    Education Department
    Parallax, Inc.

    Post Edited (Andy Lindsay (Parallax)) : 3/13/2007 10:08:52 PM GMT
  • Mike15Mike15 Posts: 109
    edited 2007-04-05 00:54
    I am currently working on a rocket payload similar. You need to know "Six Degrees of Freedom" rotation and acceleration on three axis. From there you can figure rocket translation.

    Here is a great site for what your looking for.

    http://exploration.grc.nasa.gov/education/rocket/translations.html
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