Possibile project

  • dear all, we have a possibile project where in a sort of textile fabric wire are visible, annex here you have an example where in thsi fabric you can see 2 black wires in a sort of sine wave.


    Targhet of this application is to measure

    Horizontal distance between these 2 wires

    Frequency of one of the 2 wire (sine frequency), acquisition is coming from linescan camera and for this we have a line frequency

    Phase shift between these 2 sin wave.


    the idea is to output distance and Frequency with 2 variable i can read from SDK

    rappresent the phase shift with 8 bit using the 8 digital output of a Microenable IV GigE

    i just need an idea of fesibility of this, for me measure phase shift and frequency is quite complex and i have no idea at all...


    regards

    pier

  • Hi Pier


    I think your application requires the following tasks:


    1. Find x-positions of fabric wires: Use a suitable algorithm like center of gravity, edge detection, slope, etc. The requirement is similar to a laser line detection. You could adapt the CoG algorithm from the SiSo example.

    2. Get the frequency of the lines: The important question would be over which time the measurement should take place? The FFT operators are not available for mE4VQ4-GE, however the min-positions could be used to get the period time of exactly the last period. Besides that many more options exist. The selection depends on the requirement.

    3. To detect the phase shift again the question would be: Use a specific area for the measurement or is the phase shift just the distance between two wires?

    4. IO Output: I don't clearly understand you IO output format but this should not be the most difficult part of your application.


    Johannes


    Johannes Trein
    Teamleader Applications and Development
    SiliconSoftware GmbH
    https://silicon.software/wp-content/uploads/siso-logo-animation.gif



  • Dear Johannes,

    many thanks, agree with your observation and let me talk with customer

    regarding the output on a digital IO let us suppose I have to represent a phase shift that can vary from 0 to 180°

    I can represent this variation with 7 bit digital IO and use the latest output to trigger the read from customer

    Basically 0° will be represented as binary 0000000 on first 7 Digital out, 180° will be represented as 1111111

    I’ll have a resolution of 180° over 127 possible digital output values

    The last Digital OUT (OUT8) will be set to 1 in order to “say” customer now is time to read digital output 1 to 7

    Do not know if this clarify or confuse you…. :)

    Regards

    Pier