Abstract:
PROBLEM TO BE SOLVED: To prevent the sensitivity of a mechanical rate gyroscope from including the influence of various uncertainties. SOLUTION: The gyroscope has a mechanical sensor 102 which includes a first drive system 114 for generating a drive force Fd to cause a mass to vibrate relative to a base plate, a displacement sensor 116 for measuring a deflection caused by a Coriolis force generated in response to an angular speed, and transverse drive systems 166 and 168 for generating a feedback force Ff to cancel the Coriolis force, and a control circuit which provides the first drive system with an AC drive for generating the drive force Fd, and provides the transverse drive system with a feedback signal of a complete cycle of an AC drive for generating the feedback force Ff. The first drive system includes a segment of a first number Nd. The transverse drive system includes a segment of a second number Nf, and the segment has a form equal to the segment of the first drive system and is transversely oriented relative to the segment of the first drive system. Fd/Ff is configured to be proportional to Nd/Nf. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
A micromachined sensor with quadrature suppression comprising: a quadrature suppression electrode; and a resonator mass positioned adjacent to the quadrature suppression electrode, the resonator mass capable of moving substantially parallel to the quadrature suppression electrode, the resonator mass including a notch formed adjacent to a portion of the quadrature suppression electrode such that a length of the resonator mass that is directly adjacent to the quadrature suppression electrode varies as the resonator mass moves relative to the quadrature suppression electrode, wherein the quadrature suppression electrode is capable of producing a lateral force on the resonator mass that varies based on the length of the resonator mass that is directly adjacent to the quadrature suppression electrode.
Abstract:
MEMS-Bauelement mit synchronisierter Masse, das Folgendes aufweist:ein Substrat;eine erste Prüfmasse, die durch ein erstes Halteband mit dem Substrat gekoppelt ist und zur linearen Bewegung parallel sowohl zur ersten als auch zur zweiten Querachse ausgebildet ist;eine zweite Prüfmasse, die durch ein zweites Halteband mit dem Substrat gekoppelt ist und zur linearen Bewegung parallel sowohl zur ersten als auch zur zweiten Querachse ausgebildet ist; undeinen ersten Koppler, der die erste und die zweite Prüfmasse miteinander koppelt und dazu ausgebildet ist, sich parallel zur ersten Achse linear zu bewegen und die Bewegung der ersten und zweiten Prüfmasse auf eine synchrone, lineare Gegenphasenbewegung zu beschränken, so dass, wenn sich die erste Prüfmasse in eine erste Richtung parallel zur zweiten Achse bewegt, sich die zweite Prüfmasse in eine der ersten Richtung entgegengesetzte zweite Richtung parallel zur zweiten Achse bewegt.
Abstract:
Es werden mikrobearbeitete Trägheitsbauelemente vorgestellt, die mehrere sich linear bewegende Massen aufweisen, welche durch Koppler miteinander gekoppelt sind, die sich linear bewegen, wenn die gekoppelten Massen eine Gegenphasenbewegung zeigen. Die Koppler bewegen sich in entgegengesetzte Richtungen, so dass sich ein Koppler auf einer Seite der beweglichen Massen in eine erste lineare Richtung bewegt und sich ein anderer Koppler auf der gegenüberliegenden Seite der beweglichen Massen in eine der ersten linearen Richtung entgegengesetzte zweite lineare Richtung bewegt. Die Koppler gewährleisten eine ordnungsgemäße Gegenphasenbewegung der Massen.
Abstract:
A micromachined sensor with quadrature suppression comprising: a quadrature suppression electrode; and a resonator mass positioned adjacent to the quadrature suppression electrode, the resonator mass capable of moving substantially parallel to the quadrature suppression electrode, the resonator mass including a notch formed adjacent to a portion of the quadrature suppression electrode such that a length of the resonator mass that is directly adjacent to the quadrature suppression electrode varies as the resonator mass moves relative to the quadrature suppression electrode, wherein the quadrature suppression electrode is capable of producing a lateral force on the resonator mass that varies based on the length of the resonator mass that is directly adjacent to the quadrature suppression electrode.
Abstract:
A micro-machined multi-sensor that provides 1-axis of acceleration sensing and 2-axes of angular rate sensing. The multi-sensor includes a plurality of accelerometers, each including a mass anchored to and suspended over a substrate by a plurality of flexures. Each accelerometer further includes acceleration sense electrode structures disposed along lateral and longitudinal axes of the respective mass. The multi-sensor includes a fork member coupling the masses to allow relative antiphase movement, and to resist in phase movement, of the masses, and a drive electrode structure for rotationally vibrating the masses in antiphase. The multi-sensor provides electrically independent acceleration sense signals along the lateral and longitudinal axes of the respective masses, which are added and/or subtracted to obtain 1-axis of acceleration sensing and 2-axes of angular rate sensing.
Abstract:
A micromachined device has two suspended masses (12a, 12b) positioned near each other, each of the masses being dithered along a dither axis (16). Two couplings (46), each including an arcuate member (48) and anchored support beams (52), are provided between the masses to allow relative anti-phase movement and to resist relative in-phase movement. The couplings (46) extend around a region intermediate the masses where a dither detection device is disposed.
Abstract:
Bulk acoustic wave (BAW) gyroscopes purposefully operate using non-degenerate modes, i.e., resonant frequencies of drive and sense modes are controlled so they are not identical. The resonant frequencies differ by a small controlled amount (??). The difference (??) is selected such that the loss of sensitivity, as a result of using non-degenerate modes, is modest. Non-degenerate operation can yield better bandwidth and improves signal-to-noise ratio (SNR) over comparable degenerate mode operation. Increasing Q of a BAW resonator facilitates trading bandwidth for increased SNR, thereby providing a combination of bandwidth and SNR that is better than that achievable from degenerate mode devices. In addition, a split electrode configuration facilitates minimizing quadrature errors in BAW resonators.
Abstract:
A micro-machined multi-sensor (300) that provides two axes of acceleration sensing and one axis of angular rate sensing. The multi-sensor includes a rigid accelerometer frame (330), a first proof mass (332) and a second proof mass (334). The substrate has two associated acceleration axes (Y, X) in the plane of the substrate and one associated rotation axis (Z) perpendicular to the acceleration axes. The proof masses have a common vibration axis (x), which is perpendicular to the rotation axis (Z). The multi-sensor further includes a drive electrode structure (246.1-246.2, 248.1-248.2) for causing the proof masses to vibrate in antiphase, a first pair of acceleration sense electrode structures (A, B) disposed along one of the acceleration axes, and a second pair of acceleration sense electrode structures (C, D) disposed along the other acceleration axis. The multi-sensor adds (314, 318) the sense signals provided by the respective sense electrode pairs to extract information pertaining to acceleration sensing along the acceleration axes, and (adds322) the differences (316, 320) of the sense signals provided by the respective sense electrode pairs to extract information pertaining to angular rate sensing relative to the rotation axis.
Abstract:
A mechanical rate gyroscope (100) including a micro-fabricated mechanical sensor (102). The mechanical sensor includes a first segmented drive system (114) used to impart vibration to a mass and a transverse segmented drive system (166, 168) used to cancel a Coriolis force applied to the mass when the mechanical sensor undergoes rotation. The mechanical rate gyroscope further includes a force-feedback control mechanism (158, 164) used to provide at least one cycle of drive signals employed by the first drive system to the transverse drive system. The force-feedback control mechanism generates a feedback signal used to control the polarity of the drive signals provided to the transverse drive system. The feedback signal has a pulse repetition frequency proportional to the applied angular rate. The proportionality constant relating the applied angular rate to the pulse repetition frequency includes transduction coefficients that are less sensitive to the mechanical and electrical properties of the gyroscope.