Quadrature suppression is provided by placing a resonator mass adjacent to a quadrature suppression electrode. The resonator mass is capable of moving substantially parallel to the quadrature suppression electrode and includes a notch formed adjacent to a portion of the quadrature suppression electrode such that a length of resonator mass that is directly adjacent to the quadrature suppression electrode varies as the resonator mass moves relative to the quadrature suppression electrode. The quadrature suppression electrode is capable of producing a lateral force on the resonator mass that varies based on the length of resonator mass that is directly adjacent to the quadrature suppression electrode. Such quadrature suppression can be used in sensors having one or more resonator masses.
PRIORITY
This application is a divisional of U.S. patent application Ser. No. 10/360,987 now U.S. Pat. No. 6,877,374 filed Feb. 6, 2003, currently allowed, which claims priority from U.S. Provisional Patent Application No. 60/354,610 filed Feb. 6, 2002 and U.S. Provisional Patent Application No. 60/364,322 filed Mar. 14, 2002. The above-referenced patent applications are hereby incorporated herein by reference in their entireties.
Devices and methods for reducing errors in a MEMS-type gyroscope are disclosed. A MEMS-type gyroscope in accordance with an illustrative embodiment of the present invention can include one or more proof masses configured to oscillate in a drive plane above a sense electrode for measuring Coriolis forces exerted on the one or more proof masses resulting from motion of the gyroscope about an input axis. One or more quad steering voltage members can be positioned adjacent each of the one or more proof masses and activated to electrostatically attract the proof masses toward the sense electrodes to reduce any undesired motion of the proof masses due to quadrature and/or temperature effects. The voltage applied to each of the quad steering voltage members can be time-varying, and, in some cases, can be derived from the same voltage signal used to drive the proof masses.
Devices and methods for reducing quadrature motion in a MEMS-type gyroscope are disclosed. A MEMS-type gyroscope in accordance with an illustrative embodiment of the present invention can include one or more proof masses configured to oscillate in a drive plane above a sense electrode for measuring Coriolis forces exerted on the one or more proof masses resulting from motion of the gyroscope about an input axis. One or more quad steering voltage members can be positioned adjacent each of the one or more proof masses and activated to electrostatically attract the proof masses toward the sense electrodes to reduce quadrature motion of the proof masses. A levitation force can be induced in certain embodiments to further reduce quadrature motion of the proof masses, if desired.
Resonator structures include a plurality of resonator masses interconnected by a plurality of levers so as to resonate in anti-phase with one another. The levers include a plurality of lever fingers interdigitated with corresponding fixed fingers affixed to an underlying substrate for at least one of driving movement of the levers and sensing movement of the levers relative to the fixed fingers.
Each of a number of resonator masses is split into two separate lobes or masses joined together by a short flexure. The short flexure allows the separate lobes or masses to rotate slightly as they resonate so as to substantially relieve longitudinal stresses in certain resonator structures.
