integration accelerometer

[sharir]

Hi all, I am using integration VI to convert the acceleration data from accelerometer into displacement. I am using 3-axis piezo sensor which capture data from every axial direction. The data from X and Y direction then is plotted into Cartesian plot which enable me to find the magnitude and direction of the displacement. Normally when we have single data - we just need to analyse the amplitude of each data. However the maximum amplitude of X and Y do not reflect the maximum displacement on the Cartesian plot. Could anyone suggest the best way to analyse the max displacement when we have two signal (X and Y direction)? P/S: I am totally clueless in signal processing - please advise me.. Thanks, sharir

[johnsold]

sharir,

It is not clear exactly what you are asking.

You mention a 3-axis accelerometer and then only talk about X and Y.  Are you using the Z-axis data at all?

By maximum displacement are you referring to the vector produced by the X value and Y value at a particular time t ( or equivalently at index i of the arrays)?  The magnitude of the vector is the square root of the sum of the squares of the components: r = sqrt(x^2 + y^2).

Lynn

[sharir]

Hi Lynn,

Yes, though I used 3-axis piezo sensor, I only measure on X and Y direction.

I do agree with your calculation of vector magnitude but I am looking if there any other way to analyse it. I have attached some screenshot for reference. Perhaps there are any VI in the labview which can be used to measure the data right away?

Thanks,

Sharir

[johnsold]

Converting the X and Y arrays to a complex array and finding the maximum magnitude is pretty easy.  Not a built in VI but a few simple numerical primitives will do it.

Attached VI is in LV2009.

Lynn