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.机械换能器（mechanical transducers）——包括用作激励装置、以激发待测声学或机械非线性系统的振动台（shakers）、扬声器（loudspeakers）与压缩驱动器（compression drivers）——均存在固有缺陷。本视频展示了：在使用周期信号时，可通过预失真（pre-distortion）技术抵消信号中的非线性失真。视频中包含两幅可视化图表：左侧为时域（time-domain）波形图，右侧为频域（frequency-domain）功率谱（power spectra）图。未施加预失真时，振动台生成的信号及其频谱（50 Hz谐波信号，加速度幅值为500 m/s²，对应峰值位移为10 mm）以红色标注（并在视频开头固定显示）；实时（实际）信号及其频谱则以蓝色标注。启动预失真流程（点击视频中的"Correct"复选框）后，算法可在数秒内抵消振动台引入的非期望信号分量。