Results 1 to 4 of 4

Thread: Accelerometer and Noise Filtering (Moving Average Example)

  1. #1
    Fusion Brain Creator
    Join Date
    Mar 2005
    Posts
    2,221

    Accelerometer and Noise Filtering (Moving Average Example)

    Often times, in data collection, the raw data is rather noisy. In the figure below, I have connected all 3 axes of our accelerometer to our board, and set the board to log every 100mS.

    I then moved the accelerometer through a serious of orientations, such that acceleration due to gravity (1 G) was sensed on each of the axes. As you can see, the resulting data was quite noisy.



    However, we can apply a moving average to the data inside the MDX software as follows:
    Code:
          <iochannel id="Port9" port="9" brain="TestBrain1" type="analogue_input">
            <options history="10" auto_average="true"></options>
          </iochannel>
    Note the options history and auto average. Options history specifies how many of the past parameters to hold in memory when performing the averaging calculation. For example, in this case:

    Value _new = (Value1 + Value2 + Value3 + Value4 + Value5 + Value6 + Value7 + Value8 + Value9 + Value10) / 10

    where values 1-10 are the past 10 measured values, respectively.

    Then, the accelerometer is put through a range of motions, as shown below:




    The units are 100mS and G-force.

    Hope this helps! Post any questions.

  2. #2
    FLAC is for flaccid parksgm's Avatar
    Join Date
    Dec 2005
    Location
    Dallas, Texas
    Posts
    1,119
    Quote Originally Posted by greenman100 View Post
    Hope this helps! Post any questions.
    Great post...thanks for the tips!

  3. #3
    Low Bitrate UniqelyCommon's Avatar
    Join Date
    Nov 2008
    Location
    Teh Internets
    Posts
    77
    Sorry for so many questions

    "The Fusion Accelerometer is accurate up to +/- 6G's."
    Is that the reading range or the accuracy? I know that the accelerometer the Wii remotes use have a reading range of +/- 3G's with an accuracy of 10%. http://www.wiibrew.org/wiki/Wiimote#Accelerometer

  4. #4
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,049
    reading range.

    It is accurate up to +/- 6Gs, and after that it is not.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

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
  •