Roger F. Wells

Bio: Roger F. Wells is an academic researcher. The author has contributed to research in topics: Gyroscope & Ring laser gyroscope. The author has an hindex of 2, co-authored 3 publications receiving 53 citations.

Combined gyroscope and 2-axis accelerometer

Abstract: A sensor having both gyroscope and accelerometer functions. The sensor includes a pair of masses, an anchor, a pair of support beams, a driver and a displacement measurement device. The pair of masses are configured to oscillate in a counter phase relationship with respect to each other. The anchor supports the pair of masses, and each of the support beams is used to couple one of the masses to the anchor. The driver drives the pair of masses to create a counter phase oscillation, and the displacement measurement device measures respective displacements of the masses in at least one direction. The sensor derives information regarding an acceleration experienced by the sensor in the at least one direction using a measurement of the displacements of the masses.

Sensor having both functions of gyroscope and accelerometer

Abstract: PROBLEM TO BE SOLVED: To provide a sensor having both functions of a gyroscope and an accelerometer. SOLUTION: The sensor includes a pair of mass bodies, an anchor, a pair of support beams, driving systems, and a displacement measuring device. A pair of the mass bodies are formed so as to vibrate with respect to mutually opposite phases. The anchor supports a pair of the mass bodies of which each support beam is used for connecting one of the mass bodies to the anchor. The driving system drives one of the mass bodies for generating vibrations in opposite phase and the displacement measuring device measures respective displacements in at least one direction. The sensor calculates information concerning the acceleration that the sensor receives in at least one direction by using the displacement values. COPYRIGHT: (C)2006,JPO&NCIPI

Frequency-Mismatch-Tolerant Silicon Vibratory Gyroscope without Vacuum Package for Automotive Applications

Abstract: This paper describes a low-cost silicon vibratory gyroscope that tolerates a relatively large mismatch between the driving-mode and sensing-mode frequencies. The gyroscope is based on beam-mass structure and realized by one silicon proof mass and two beams for the driving and sensing mode. Piezoelectric actuation is used to produce a large driving mode vibration displacement (about 100 mum) with about 32 Vpeak-to-peak. Two tiny sensing beams are separated from the vertical silicon beam to increase the sensitivity while keeping the sensing-mode resonant frequency high. Piezoresistive and piezoelectrical sensing mechanisms are applied to two different gyroscopes. The gyroscope operating at 1-4 kHz is capable of sub-degree-per-second angular rate sensitivity without any vacuum package.

Yaw rate sensor

Abstract: A yaw-rate sensor having a substrate and a plurality of movable substructures that are mounted over a surface of the substrate, the movable substructures being coupled to a shared, in particular, central spring element, means being provided for exciting the movable substructures into a coupled oscillation in a plane that extends parallel to the surface of the substrate, the movable substructures having Coriolis elements, means being provided for detecting deflections of the Coriolis elements induced by a Coriolis force, a first Coriolis element being provided for detecting a yaw rate about a first axis, a second Coriolis element being provided for detecting a yaw rate about a second axis, the second axis being oriented perpendicularly to the first axis.

A single-crystal silicon vibrating ring gyroscope

Abstract: This paper reports a high-performance vibrating ring gyroscope fabricated in (111) oriented single-crystal silicon (SCS). High-performance microgyroscopes are needed in many applications, including inertial navigation, control, and defense/avionics/space. The ring gyroscope provides a number of advantages, including excellent mode matching, high-resolution, low zero-rate output, and long-term stability. In this paper, a SCS vibrating ring gyroscope with high aspect ratio silicon on glass structure was designed, fabricated and tested. The ring is 2.7mm in diameter and 150μm thick. The gyro has the following measured performance: high Q (12000), good nonlinearity (0.02%), large sensitivity (132 mV/°/sec), low output noise (10.4°/hr/Hz) and high resolution (7.2°/hr). The maximum bias shift is less than ±1°/sec over 10 hours without thermal control.

Micromachined inertial sensor devices

Abstract: A micromachined inertial sensor (200) with a single proof-mass (201) or measuring 6-degree-of-motions. The single proof-mass (201) includes a frame (202), an x-axis proof mass section (212a, 212b) attached to the frame by a first flexure, and a y-axis proof mass section (218) attached to the frame (202) by a second flexure (228a, 228b). The single proof-mass (201) is formed in a micromachined structural layer and is adapted to measure angular rates about three axes with a single drive motion and linear accelerations about the three axes.

Microelectromechanical pressure sensor including reference capacitor

Abstract: This document discusses, among other things, an apparatus including a silicon die including a vibratory diaphragm, the die having a silicon die top opposite a silicon die bottom, with a top silicon die port extending from the silicon die top through the silicon die to a top of the vibratory diaphragm, and with a bottom silicon die port extending from the silicon die bottom to a bottom of the vibratory diaphragm, wherein the bottom silicon die port has a cross sectional area that is larger than a cross-sectional area of the top silicon die port, a capacitor electrode disposed along a bottom of the silicon die, across the bottom silicon die port, the capacitor electrode including a first signal generation portion that is coextensive with the top silicon die port, and a second signal generation portion surrounding the first portion.

Sealed packaging for microelectromechanical systems

Abstract: One example includes an integrated circuit including at least one electrical interconnects disposed on an elongate are extending away from a main portion of the integrated circuit and a microelectromechanical layer including an oscillating portion, the microelectromechanical layer coupled to the main portion of the integrated circuit, wherein the microelectromechanical layer includes a cap comprising a membrane that extends to the integrated circuit.