In AE signal processing, the RMS calculation is normally done
after having the raw signal filtered. Due to the very small time constant
used in the RMS calculation, it was established that a high pass
filter with a cut-off frequency of 100 kHz be used. A specific AE
signal processing unit has been developed for this system. The data
acquisition is made in data groups where each 1-dimention array of
data corresponds to a full rotation of the grinding wheel. The AE
signal acquisition starts in each rotation triggered by a magnetic sensor
positioned in the wheel hub where a reference pin is installed. A
graphical mapping of the AE signal with a color intensity scale is
then created. During the wheel dressing operation, the mapping is
constructed in real time by adding columns in the array as the
dresser travels along the wheel surface.