How to implement lowpass filter to reduce noise in gyroscope values?

Question

I am new to labview and I need help.

I am using myrio with gyroscope, and when I display the gyroscope values I get noise.

My question is: How can I implement lowpass filter to reduce the noise in X , Y and Z rates of the gyroscope?

I searched a lot, but I did not understand how can I know what is the sampling frequency, the low and the high cutoff frequency.

Thank you so much.

Answer 1

If you're data is noisy you should try to fix the problem before you digitize the data. If a physical low-pass filter will do the trick, install one. The better the signal before the DAQ the better the data will be once it's digitized.

Some other signal conditioning considerations: make sure to reduce the length of wire from the gyroscope to the DAQ to only what's necessary, if possible eliminate any sources of noise from the environment (like any large rotating magnets--seriously I once helped someone who was complaining about noise when they were using an unshielded wire next to an MRI machine), and if you're going to add any signal conditioning try to amplify close to your sensor.

If you still would like to filter in software, there's an example included with LabVIEW that demonstrates both the point-by-point VIs and the array based VIs. It's called PtByBp and Array Based Filter.vi and can be found in the Example Finder under Analysis, Signal Processing and Mathematics >> Filtering and Conditioning

Answer 2

Sampling frequency is how fast you sample. Look for this value in the ADC settings. Low and high cutoffs - play with those values. Doing an FFT on your signal may help you to determine spectral frequency density, and decide where to cut.

Answer 3

Please install this FREE toolkit from ni.com: http://sine.ni.com/nips/cds/view/p/lang/en/nid/212733

There are examples and good ready to use application how to use myRIO gyroscope and how to do proper DSP.