Micromachined Gyroscope Design Allowing for Both Robust Wide-Bandwidth and Precision Mode-Matched Operation
Camera stabilization; Personal navigation; GPS augmentation; Automotive electronic stability control
The robust mode corresponds to operation between the 2-DOF sense mode resonant frequencies providing a response gain and bandwidth controlled by frequency spacing. Precision mode of operation, however, relies on mode matching the drive to the second, anti-phase sense mode resonant frequency which can be designed to provide a gain advantage over a similar 1-DOF system. Experimental rate characterization of an SOI prototype in air for both robust and precision modes revealed scale factors of 0.282 and 0.690 mV/deg/s respectively. The improvement due to precision mode operation is increased to 27 times for operation in 500 mTorr reduced pressure.
Patent Number: US8549915B2
Application Number: US2009605178A
Inventor: Schofield, Adam | Trusov, Alexander | Shkel, Andrei
Priority Date: 23 Oct 2009
Priority Number: US8549915B2
Application Date: 23 Oct 2009
Publication Date: 8 Oct 2013
IPC Current: G01C001956
US Class: 7350412
Assignee Applicant: The Regents of the University of California
Title: Micromachined gyroscopes with 2-DOF sense modes allowing interchangeable robust and precision operation
Usefulness: Micromachined gyroscopes with 2-DOF sense modes allowing interchangeable robust and precision operation
Novelty: Micromachined z-axis vibratory rate gyroscope, has single-degree of freedom drive subsystem having drive frequency that is determined by selection of dynamic parameters for drive suspension and drive mass
电子
计算机，通信和消费电子产品 /小工具
8549915
Background Micromachined vibratory gyroscopes operate based on the Coriolis effect where a rotation induced energy transfer occurs between two orthogonal vibrational modes, commonly referred to as drive and sense. Conventionally, these modes are realized as single degree of freedom (DOF) dynamic systems with their own associated resonant frequencies giving rise to two differing methods of operation: mode-matched or mismatched. In mode-matched devices, the drive and sense resonant frequencies are equal allowing the output of the sensor to be increased proportional to the sense mode quality factor yielding higher sensitivities at the cost of reduced bandwidth and robustness. Operation with the resonant frequencies separated by some prescribed amount, or mode-mismatched, is more common, particularly for automotive applications where robustness is critical. Gyroscope design concepts have been introduced aimed at robust operation using an expanded sense mode design space through increased degrees of freedom. Specifically, the device used two coupled sense masses forming a 2-DOF dynamic system with two sense mode resonant frequencies and a wide region of constant amplitude between them. While the gain and the bandwidth of this operational region is controlled solely by the resonant frequency spacing, a constraint limited the minimal achievable spacing as the operational frequency of these devices with fixed size was increased. This is a direct effect of the dynamic vibration absorber type 2-DOF design which utilized only two suspensions thereby eliminating the ability to independently define the frequency spacing and the coupling between the masses. In contrast, a complete 2-DOF system consisting of two masses and three suspensions alleviates this issue allowing for the arbitrary specification of frequency spacing independent of operational frequency. Additional Technologies by these Inventors Tech ID/UC Case 19582/2009-547-0 Related Cases 2009-547-0
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