Expanding the Bandwidth of Rotational Accelerometers by Autonomous Gain-phase Tailoring

The concept of an autonomous gain - phase piezoelectric device is adapted to the design of a rotational accelerometer. It can be shown that a no-phase-delay low-pass filter can be introduced into the transfer function of an accelerometer by weighting the structure vibration strain spatially. This can be achieved by modifying either the shape or the effective surface electrode of a thin layer piezoelectric film. With the introduction of this new class of filter, the usable bandwidth of the rotational accelerometer created can be shown to expand significantly. It can also be demonstrated that the concept is applicable to mechanical systems that can be represented using a second-order partial differential equation including a shaft, rod, etc. To verify the performance of the newly developed rotational accelerometer, which is difficult to test due to its wide bandwidth, the design and implementation of a testing methodology based on a wideband rotational shaker is also detailed.