A Stable Parametrically Amplified Gyroscope

尽管工业界和学术界在提高制造精度、大规模修整和信号处理方面付出了巨大的努力，但在MEMS陀螺仪挑战其他陀螺仪技术的性能之前，仍需要进行相当大的改进。提出的研究目标是开发一种激励方案，使典型的静电驱动MEMS陀螺仪的振动感测和驱动模式的q因子能够稳定地参量放大，从而将陀螺仪的性能提高至少一个数量级。参数放大减少了谐振器中存在的总阻尼（粘性和热弹性），可以解释为有效q因子的放大或力的放大。在常规激励陀螺仪中，为了实现高性能，必须尽量减少重要振动模式之间的失谐。通过采用参数激励和放大，可以容忍的错调程度增加，并将允许q因子放大对陀螺仪性能的影响最大化。消除精确调谐模式的需要本身就是一个重要的发展，当与q因子的参数放大相结合时，MEMS陀螺仪性能的阶跃变化前景是一个明显的可能性。它有可能将速率级陀螺仪转变为战术级陀螺仪。这项工作也非常适用于谐振MEMS/NEMS传感器，其中高q因子对传感器性能至关重要。我们建议通过参数作用建立可能的放大的全部程度，其限制因素，并制定必要的方案，以在实际的MEMS陀螺仪中最佳地使用它。

Despite the huge industrial and academic effort in advancing both the precision of the fabrication, mass trimming and signal processing there is still a considerable amount of improvement required before MEMS gyroscopes challenge the performance of other gyroscopic technologies. The objective of the proposed research is to develop an excitation scheme to enable stable parametric amplification of the Q-factors of the sense and drive modes of vibration of a typical electrostatically driven MEMS gyroscope and thus improve gyroscopic performance by at least an order of magnitude. Parametric amplification reduces the amount of total damping (viscous and thermoelastic) present in a resonator and may be interpreted as amplification in the effective Q-factor or as force amplification. Mis-tuning between the important modes of vibration must be minimised in conventionally excited gyroscopes to realise high performance. By employing parametric excitation and amplification the degree of mis-tuning that can be tolerated is increased and will allow the affect of Q-factor amplification on the gyroscope performance to be maximised. Eradicating the need to precisely tune the modes is in itself an important development and when combined with the parametric amplification of the Q-factor the prospect of a step change in MEMS gyroscope performance is a distinct possibility. It has the potential to transform a gyroscope which is rate grade to tactical grade. This work is also very applicable to resonant MEMS/NEMS sensors in general where high Q-factors are essential for the sensor performance. We propose to establish the full extent of amplification possible via parametric action, its limiting factors and develop the scheme necessary to use it optimally in actual MEMS gyroscopes.