A simple predistortion technique for suppression of nonlinear effects in periodic signals generated by nonlinear transducers.
Mechanical transducers, such as shakers, loudspeakers and compression drivers that are used as excitation devices to excite acoustical or mechanical nonlinear systems under test are imperfect. This video demonstrates that when using periodic signals, the nonlinearities can be cancelled out from the signal using a pre-distortion technique. Two graphs are visible in the video, time-domain on the left hand side and frequency-domain (power spectra) on the right hand side. The signal and spectra generated by a shaker (a harmonic signal at 50 Hz with acceleration amplitude of 500 m/s2, which is equivalent to 10 mm peak displacement) without pre-distortion is depicted in red (and fixed at the beginning of the video), the real-time (actual) signal and spectra are depicted in blue. After starting the pre-distortion procedure (checking the checkbox "Correct" in the video), the algorithm cancels out the undesired components of the shaker within few seconds.
Steps to reproduce
Submitted to Journal of Sound and Vibrations (2017), - entitled: "A simple predistortion technique for suppression of nonlinear effects in periodic signals generated by nonlinear transducers." - under review