Design and Performance of a PZT Coriolis Vibrating Gyro (CVG)

A new piezoelectric Coriolis vibrating gyro (CVG) is presented in this article. There is a real need for integrated inertial sensors (e.g. for vehicle attitude control or inertial navigation) and ONERA (the French National Establishment for Aerospace Research) has been developing a quartz micromachined CVG called VIG (vibrating inertial gyro). Quartz was chosen in regard to its mechanical quality and temperature stability, but nevertheless the sensor resolution is limited by its low piezoelectric properties. To enhance CVG performances one possibility is to use stronger piezoelectric material (since the resolution is directly linked to piezoelectricity the material performance). As Perovskite ferroelectric materials are strongly piezoelectric - PZT ceramics (d₃₁=150pC/N) are hundreds of times more piezoelectric than quartz (d₁₁=2.3pC/N) -they offer new possibilities in CVG development. In this paper are presented the design, the performance and the resolution of a new monolithic piezoelectric CVG made of a PZT ceramic. Such a gyro could achieve a resolution of 0.2 deg/h. A brief discussion of key intrinsic material parameters is also made.