Signal Processing with LabVIEW

This chapter discusses analogue and digital filters for sensor signal processing. The main usage of signal-processing techniques is in pre- and postprocessing of sensor signals that deal with the so-called aliasing phenomenon common in data acquisition systems and generally to clean up noisy signals. The chapter introduces the reader to analogue low-pass filters using passive and active components, as well as digital, moving average (alternately, finite impulse response), and autoregressive moving average (alternately, infinite impulse response) filters. Implementation via virtual instruments is demonstrated through graphical displays of pre- and postfiltered signals. Signal-processing tools built from discrete LabVIEW components, as well as those based on prepackaged LabVIEW filters, are used to demonstrate how a signal-processing tool set can be implemented. Exercises supplement the discussion through additional examples that enable the reader to develop effective measurement systems.