Improving Torque Data Signal with Digital Filtering

[Trainee28]

Hello,

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.

 

[Hesch]

It seems that you are measuring the torque after the brake. The curve for the torque does not reflect the curve for the current.

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?

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.