Filtering the signal of a measured mechanical parameter

The paper presents a filter that has been specially designed to filter a previously known noise that occurred during recording a torque signal on a transmission shaft of a vehicle. At the beginning, the problem seemed to be simple. But it wasn´t... Due to the mounting necessities, the balancing counterweights of the universal joint´s shaft have been removed, thus a permanent noise have been introduced. Hence, the necessity to remove the noise. The problem of the filter was to determine the specific frequency and the noise´s amplitude. The issue has been solved using the spectral analysis methods, provided by designated software. However, we could take advantage by the fact that we knew what the source of the noise was acting like.