Abstract: A method and system for a sensor system of a device is disclosed. The sensor system includes a first MEMS sensor (FMEMS), a second MEMS sensor (SMEMS) and a signal processor (SP). An excitation is imparted to the device along a first axis (FA). The FMEMS has a first primary sense axis (FPSA), moves in response to a component of the excitation along the FA aligned with the FPSA and outputs a first signal proportional to an excitation along the FPSA. The SMEMS has a second primary sense axis (SPSA), moves in response to a component of the excitation along the FA aligned with the SPSA and outputs a second signal proportional to an excitation along the SPSA. The SP combines the first signal and the second signal to output a third signal proportional to the excitation along the FA. The FA, the FPSA and the SPSA have different orientations.

Abstract: A method and system for the ultrasonic non-destructive testing of joints in plastic pipes using A-scans. A hand-held ultrasonic transducer is used to perform an A-scan and a comparison made on a response from the interface region of the joint used to determine a quality of the joint. Levels of result can provide a binary output to give an indication of whether or not a defect is present in the joint. Comparison techniques are described. Tests for coupling efficiency and performance are described making the system useable by an unskilled technician. The system finds application in fault detection on electro-fusion welds in plastic pipe joints.

Abstract: An online real time steam or gas turbine engine rotor balancing system is incorporated in a rotor balance plane. A selectively displaceable balancing weight is coupled to the rotor and is selectively displaced by a motor that is coupled to the balancing weight. The motor selectively displaces the balancing weight along a displacement path that is in the balance plane. A turbine engine rotor vibration monitoring system monitors rotor vibration in real-time. A control system is coupled to rotor vibration monitoring system and the motor, for determining in real time a desired balance weight displacement position to counteract the monitored rotor vibration. The controller selectively causes the motor to displace the balancing weight to the desired displacement position. The motor power source is an inductive power source or a permanent magnet generator.

Abstract: A vibration gyro having high bias stability, and a method of using the gyro for obtaining a precise angular velocity signal by correcting the bias. The gyro has: a drive signal generating part configured to generate a multiplexed drive signal; first and second demodulation circuits configured to generate first and second demodulation signals, respectively; first and second control circuits configured to generate first and second feedback amplitude signals, respectively; a feedback signal generating part configured to generate a first multiplexed feedback signal by multiplexing a first feedback signal obtained by modulating the first feedback amplitude signal at the first frequency, and at least one second feedback signal obtained by modulating the second feedback amplitude signal at the at least one second frequency; and a subtracter configured to output an angular velocity signal by subtracting the second feedback amplitude signal from the first feedback amplitude signal.

Abstract: An angular rate sensor includes four Coriolis masses, configured such that the Coriolis masses move along perpendicular drive and sense axes, and a lever mechanism having first and second sets of levers. The first set of levers is coupled outside a boundary of the Coriolis masses, and the second set of levers is coupled within a boundary of the first set of levers and between the Coriolis masses. The second set of levers is configured to produce an anti-phase drive mode motion of the Coriolis masses along the drive axis. The first set of levers is configured to allow an anti-phase sense mode motion of the Coriolis masses along the sense axis responsive to the angular rate sensor rotating around an input axis that is perpendicular to the drive and sense axes. The first and second sets of levers are configured to constrain an in-phase motion of the Coriolis masses.

Abstract: Provided is a highly reliable acceleration sensor having little 0-point drift. For example, an acceleration sensor having a support substrate having a first direction and a second direction orthogonal thereto in a single surface, a device layer disposed on the support substrate with a space interposed therebetween and having a weight that deforms according to the application of acceleration, and a cap layer disposed on the device layer with a space interposed therebetween, wherein a fixed part fixed to the support substrate is provided in the center of the weight, a beam is provided that extends from the fixed part and makes the weight mobile by being connected thereto, a plurality of posts for coupling the support substrate and the cap layer are disposed on the fixed part, and electric signals are applied to and received from the weight via the posts.

Abstract: According to one aspect, embodiments herein provide a gyroscope comprising an axially symmetric structure, and a plurality of transducers, each configured to perform at least one of driving and sensing motion of the axially symmetric structure, wherein the plurality of transducers is configured to drive the axially symmetric structure in at least a first vibratory mode and a second vibratory mode, and wherein the gyroscope is implemented on a hexagonal crystal-based substrate.

Abstract: A physical quantity detection circuit includes: a synchronous detection circuit that performs a synchronous detection process on a detection target signal based on a detection signal, the detection target signal including a physical quantity detection signal and a leakage signal from a physical quantity detection element, the physical quantity detection element vibrating based on a drive signal to generate the physical quantity detection signal corresponding to a magnitude of a physical quantity, and the leakage signal of vibrations based on the drive signal; and a phase shift circuit that switches a phase difference between the detection signal and the detection target signal, between a first phase difference and a second phase difference that differs from the first phase difference, so that at least part of the leakage signal is output through the synchronous detection process.

Abstract: A direct field acoustic testing system includes at least one control microphone, a controller operatively coupled to the control microphone such that the controller receives at least one input signal from the control microphone, and at least four acoustic transducer groups operatively coupled to the controller such that each transducer is separately controllable by the controller such that a separate output signal is received by each transducer from the controller. A setup signal is applied to each of the acoustical transducers. The acoustic output of each of the acoustical transducers is monitored using the at least one control microphone. Assumptions regarding the relationship between the acoustic fields measured by the control microphones are made to enable the controller to reduce the number of calculations needed to compute error functions and corrected drive signals to be applied to the acoustic transducer groups.

Abstract: A MEMS device including a fixed member and a movable member supported via a resilient body. The MEMS device includes an impact alleviation mechanism provided at a position where the movable member and the fixed member collide during operation. The impact alleviation mechanism includes a stopper provided to either the fixed member or the movable member and that protrude to be parallel between sides of the two members with at least one side edge fixed to the respective member. Moreover, the impact alleviation mechanism includes an elongate protruding member provided on the other of the fixed member and the movable member. The elongate protruding member and the stopper are configured such that as collision force increases between the movable member and the fixed member during operation, an abutment area of an outer edge position of the elongate protruding member approaches the fixed side edge of the stopper.

Abstract: A substrate for a sensor includes: a base section; a movable section connected to the base section; an arm portion as a support portion extending along the movable section from the base section; a first gap portion having a protrusion portion in which one of the movable section and the arm portion protrudes toward the other of the movable section and the arm portion, and having a predetermined gap between the protrusion portion on one side and the other of the movable section and the support portion; and a second gap portion which is located further toward the base section side than the first gap portion has a gap wider than the predetermined gap, in which in the first gap portion, one of the movable section and the arm portion has a ridge portion on the side facing the first gap portion.

Abstract: A microelectromechanical system (MEMS) gyroscope device includes a substrate having a surface parallel to a plane; first and second proof masses driven to slide back and forth past one another in a first directional axis of the plane, where the first and second proof masses respectively have a first and second recess in a respective side closest to the other proof mass; a pivot structure coupled to the first proof mass within the first recess and to the second proof mass within the second recess; an anchor between the first and second recesses and coupled to a mid-point of the pivot structure; and third and fourth proof masses driven to move toward and away from one another in a second directional axis of the plane that is perpendicular to the first directional axis; where the proof masses move in response to angular velocity in one or more directional axes.

Abstract: Single ended tuning fork inertial sensor having a housing and a single ended tuning fork of a quartz-like material of a predetermined thickness, the tuning fork has first and second tines lying in a plane and having an axis of symmetry and has a body formed integral with said first and second tines. The body is rigidly secured to the housing. The tines have a rectangular cross section and have a width which is different from the thickness. The body has a stem formed therein which has a width less than that of the body. Drive electrodes are secured to the tines. An oscillatory frequency is supplied to the above drive electrodes to excite the tines in a drive mode and in the presence of an axial angular rate to cause the tines to operate in a pickup mode which is substantially separated in frequency from the drive mode. The electrode patterns are laser trimmed in order to reduce quadrature offset.

Abstract: An angular velocity sensor utilizing the Coriolis effect on a fluid jet employs a metal diaphragm impulse jet pump with no valves to reduce temperature sensitivity. The pump anvil, the nozzle block and the sensor plug may all be fabricated of the same material to further reduce temperature sensitivity. The thickness of the sensing elements is selected to reduce temperature sensitivity still further.

Abstract: An angular velocity sensor utilizing the Coriolis effect on a fluid jet employs increased spacing between the sensing elements to increase the scale factor and to reduce flow disturbances. A metal diaphragm pump is utilized to improve the ability to control the flow rate. Flow disturbances are further reduced by using a single, symmetrical central flowhole, eliminating curtain holes, and providing only two discharge paths oriented 180.degree. apart.

Abstract: A system for determining angular rate of rotation of a body about a rate axis. In one arrangement, the system comprises first (10) and second (12) accelerometers, movement apparatus and processor. The first and second accelerometers have their sensitive axes (16, 18) parallel to a sensing axis that is in turn perpendicular to the rate axis. The first and second accelerometers produce first and second output signals (a.sub.1, a.sub.2), each output signal having a frequency corresponding to the acceleration experienced by the respective accelerometer along its sensitive axis. The movement apparatus includes a generator (68) for producing a periodic movement signal and a mounting system (14) responsive to the movement signal for periodically moving the accelerometers along a movement axis perpendicular to the rate and sensing axes, such that each output signal includes a periodic Coriolis component.

Abstract: Liquid bearing two degree of freedom inertial sensor apparatus is disclosed. A single liquid bearing sensor is configured in a two degree of freedom rate gyro mode, or two of the liquid bearing sensors are made pendulous along their spin axes and configured in a two degree of freedom rate gyro and accelerometer mode.

Abstract: This invention relates to an ultrasonic angle test probe comprising at least two ultrasonic transducers for respectively generating and receiving ultrasonic waves propagating in different directions. According to the invention, in order to obtain relatively small wedge shaped coupling members and small coupling surfaces on the side of the probe contacting the workpiece, a plurality of transducers are disposed above one another instead of side by side. In a typical embodiment, a first transducer is disposed on a first wedge-shaped coupling member and second transducer is disposed on a second wedge-shaped coupling member superposed upon said first coupling member for providing different angles of propagation of sound waves responsive to energizing one or the other transducer.

Abstract: An accelerometer fabricated from a semiconductor substrate sandwiched between two non-conductive plates is shown having an inertial mass formed by etching the substrate. The mass is joined to the substrate by hinges having crossed blades to provide flexure in one direction and rigidity in other directions. The fabrication technique permits the integration of accelerometer servo and signal processing circuitry upon the same substrate in which the accelerometer mass is formed.

Abstract: Disclosed is a method and apparatus for measuring the density of a liquid, such as a drilling mud, by continuously flowing a sample of the liquid through a container having a fixed predetermined volume. The container is supported by at least one bed of pressurized fluid. The pressure of the fluid is varied in response to fluctuations in the weight of the liquid sample in the container. A pressure transmitter monitors the pressure level in the bed and produces a signal indicative of the density of the liquid sample.