Abstract: A strut suitable for use in parallel manipulator and other applications utilizes an actuation member that is subjected to a quasi-static axial tensioning force to effectively preload the strut to provide axial stiffness and bending flexibility at one or more ends of the strut.

Abstract: An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

Abstract: An active mechanical waveguide including an ultrasonically-transmissive material and a plurality of reflection points defined along a length of the waveguide may be driven at multiple resonant frequencies to sense environmental conditions, e.g., using tracking of a phase derivative. In addition, frequency-dependent reflectors may be incorporated into an active mechanical waveguide, and a drive frequency may be selected to render the frequency-dependent reflectors substantially transparent.

Abstract: A sensor with a mechanical waveguide may be characterized using test ultrasonic signals to generate a baseline signature, and the baseline signature may later be used to detect faults in the sensor.

Abstract: A strut suitable for use in parallel manipulator and other applications utilizes an actuation member that is subjected to a quasi-static axial tensioning force to effectively preload the strut to provide axial stiffness and bending flexibility at one or more ends of the strut.

Abstract: An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

Abstract: An active mechanical waveguide including an ultrasonically-transmissive material and a plurality of reflection points defined along a length of the waveguide may be driven at multiple resonant frequencies to sense environmental conditions, e.g., using tracking of a phase derivative. In addition, frequency-dependent reflectors may be incorporated into an active mechanical waveguide, and a drive frequency may be selected to render the frequency-dependent reflectors substantially transparent.

Abstract: An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

Abstract: A broadband waveguide comprising at least one filament configured to transmit a signal therethrough. The broadband waveguide may include one or more reflection suppression techniques including a damping material coupled to at least a portion of the at least one filament and/or at least one reflection point configured thereon. The waveguide may further including a cladding material coupled to the at least one filament. The at least one filament may be coupled to a securing element configured to couple to a surface. The at least one filament may be coupled to a sensor configured to sense the transmitted signal.

Abstract: A method and apparatus for a flowmeter (5) is provided. The method comprises the steps of placing a material in a flow tube (130, 130?) while exciting a vibration mode of the flow tube (130, 130?). Exciting the vibration mode of the flow tube (130, 130?) comprises the steps of periodically driving a first driver (180L) with a first signal and periodically driving a second driver (180R) with a second signal, wherein the second driver (180R) is driven essentially in phase with the first driver (180L), but wherein the first driver's (180L) drive amplitude modulated signal reaches a maximum amplitude when the second driver's (180R) drive modulated signal reaches a minimal amplitude, and the first driver's (180L) drive amplitude modulated signal reaches a minimum amplitude when the second driver's (180R) drive amplitude modulated signal reaches a maximum amplitude.

Abstract: A sensor with a mechanical waveguide maybe characterized using test ultrasonic signals to generate a baseline signature, and the baseline signature may later be used to detect faults in the sensor.

Abstract: An active mechanical waveguide including an ultrasonically-transmissive material and a plurality of reflection points defined along a length of the waveguide may be dampened using a damping device on a plurality of support members for the waveguide and/or using a damping device on the waveguide itself, and variable spacing of support members and/or constant tensioning of the waveguide may also be used.

Abstract: A composite active waveguide temperature sensor (10) incorporates a first, sensor portion (16) formed of an environment-resistant material such as ceramic coupled through an ultrasonically-transparent bond (20) to a second, waveguide portion (18) formed of an ultrasonically-transmissive material such as a metallic filament wire. By doing so, the sensor portion (16) may be positioned within a harsh environment and subjected to a temperature to be measured, and the waveguide portion (18) may be used to propagate ultrasonic energy to and/or from the sensor portion (16) to a location distal from the harsh environment for measurement of the temperature. The ultrasonically-transparent bond (20) between these portions (16, 18) limits attenuation of and the introduction of reflections and other noise to an ultrasonic signal propagated across the bond (20).

Abstract: A broadband waveguide comprising at least one filament configured to transmit a signal therethrough. The broadband waveguide may include one or more reflection suppression techniques including a damping material coupled to at least a portion of the at least one filament and/or at least one reflection point configured thereon. The waveguide may further including a cladding material coupled to the at least one filament. The at least one filament may be coupled to a securing element configured to couple to a surface. The at least one filament may be coupled to a sensor configured to sense the transmitted signal.

Abstract: A method and apparatus for a flowmeter (5) is provided. The method comprises the steps of placing a material in a flow tube (130, 130?) while exciting a vibration mode of the flow tube (130, 130?). Exciting the vibration mode of the flow tube (130, 130?) comprises the steps of periodically driving a first driver (180L) with a first signal and periodically driving a second driver (180R) with a second signal, wherein the second driver (180R) is driven essentially in phase with the first driver (180L), but wherein the first driver's (180L) drive amplitude modulated signal reaches a maximum amplitude when the second driver's (180R) drive modulated signal reaches a minimal amplitude, and the first driver's (180L) drive amplitude modulated signal reaches a minimum amplitude when the second driver's (180R) drive amplitude modulated signal reaches a maximum amplitude.

Abstract: An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

Abstract: A broadband waveguide comprising at least one filament configured to transmit a signal therethrough. The broad-band waveguide may include one or more reflection suppression techniques including a damping material coupled to at least a portion of the at least one filament and/or at least one reflection point configured thereon. The waveguide may further including a cladding material coupled to the at least one filament. The at least one filament may be coupled to a securing element configured to couple to a surface. The at least one filament may be coupled to a sensor configured to sense the transmitted signal.

Abstract: A composite active waveguide temperature sensor (10) incorporates a first, sensor portion (16) formed of an environment-resistant material such as ceramic coupled through an ultrasonically-transparent bond (20) to a second, waveguide portion (18) formed of an ultrasonically-transmissive material such as a metallic filament wire. By doing so, the sensor portion (16) may be positioned within a harsh environment and subjected to a temperature to be measured, and the waveguide portion (18) may be used to propagate ultrasonic energy to and/or from the sensor portion (16) to a location distal from the harsh environment for measurement of the temperature. The ultrasonically-transparent bond (20) between these portions (16, 18) limits attenuation of and the introduction of reflections and other noise to an ultrasonic signal propagated across the bond (20).

Abstract: A method and apparatus for periodically calculating the relative phase of the left eigenvector for a vibrating conduit is provided. During normal operation, two drivers are used in tandem to excite the main bending mode of the conduit (202). Periodically, first one (204), then the second (206), of the two drivers is disabled, allowing measurements that enable the determination of the relative phase of the left eigenvector (208) for the vibrating conduit.

Abstract: A method and apparatus is disclosed that measures the flow through a conduit (702) by measuring the Coriolis coupling between two vibration modes in the conduit. The conduit is first excited at two different vibration modes at two different frequencies (704). The coupling between the two modes is determined by forcing the phases of the two modes at the off mode frequency to be zero (708). The flow through the conduit can then be determined using the magnitude of the forces required to drive the phases of the two modes at the off mode frequency to zero (710).