Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Torque data signal processing

  1. Jul 3, 2015 #1

    I have a three phase brushless motor and was trying to measure its torque and speed using a torque sensor. The motor will first go to its maximum speed which is about 6000RPM, then I applied a brake to decrease its velocity. Here is what I get as a result of data acquisition :
    The problem is that the torque signal looks kinda mess up. I wish to get a signal as nice as the RPM. Does anyone know how can this be done? Some kind of signal processing steps?

    Please help me.

    Attached Files:

  2. jcsd
  3. Jul 3, 2015 #2


    User Avatar
    Gold Member

    It seems that you are measuring the torque after the brake. The curve for the torque does not reflect the curve for the current.
    If the data are sampled digitally, you can insert a digital filter ( z-transform ) like for example:

    H(z) = 0.01z2 / ( ( z - 0.9 ) ( z - 0.9 ) ) = 0.01z2 / ( z2 - 1.8z + 0.81 )

    ( The amplification = 0.01 / ( 1 - 0.9 )2 = 1 )

    You can put your already sampled data through such a filter and redraw the result.
    Last edited: Jul 3, 2015
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook