Multifunction DAQ

Showing results for 
Search instead for 
Did you mean: 

convert angle to speed



i am trying to meaure the speed of a motor . I have angular encoders attached to it and hence i get angle data..

 i am trying to convert it to speed by derivative method but theres too much noise being added in...

i tried using filters( lowpass butterworth) to filter the noise out , still theres too much noise.. and plus an offset gain by the filter..

 all of these are in labview 8.5 and in real time..

Any other way to measure speed???

any speed sensors anybody know??

 or any documents related to working with LV real time for matters similar??

I dont really understand working with LVRT either...


please if any suggestions???



0 Kudos
Message 1 of 3



One way to reduce noise with these type of measurements is to use a differential encoder as mentioned in this Developer Zone article.  Unfortunately, our cards do not natively support using a differential encoder.  In order to get around this you could try the procedure detailed in this Knowledgebase that uses a little bit of external circuitry.


There are other ways to measure speed but this is a pretty good one and really it depends on your application.  When you say "i am trying to convert it to speed by derivative method" what do you mean?  I am used to a certain number of ticks being a rotation and just using simple math to calculate the number of rotations per amount of time like in this article.


We don't directly deal in sensors too much so my best advice here might be the differential mentioned in the first paragraph.


We have plenty of documents about working with LabVIEW Real time here are a view of them: Training course, general getting started, and new in 2009.


Finally lets work on this thread and let this other duplicate thread go.

Jason Daming
Applications Engineer
National Instruments
0 Kudos
Message 2 of 3
Can you post your code?
Randall Pursley
0 Kudos
Message 3 of 3