Environmental sensor with tensioned wire exhibiting varying transmission characteristics in response to environmental conditions

Systems and methods for measuring environmental conditions of a sensing location, where a sensor including a measuring surface and a wire coupled in tension to the measuring surface over which ultrasonic signals may be transmitted and sensed. Signal analysis of ultrasonic signals transmitted over the tensioned wire are analyzed to measure one or more environmental conditions acting on the measuring surface.

FIELD OF THE INVENTION

The present invention relates to sensing technology, and more particularly to sensors and sensing methods.

BACKGROUND OF THE INVENTION

Many conventional mechanical systems are monitored to determine operating conditions such as pressure, temperature, vibrations, etc. However, in many systems it is desirable to monitor and measure operating conditions at locations in the system where it is extremely difficult to do so. For example, the measurement environment may be a harsh environment in which sensors are unable to operate reliably. For example, monitoring an aero gas turbine engine presents unique challenges due to the harsh environmental conditions of the engine, i.e., high temperatures, high pressures, and high vibrations a sensor is subjected to during operation of the engine. In mechanical systems, conventional sensors used to monitor operating conditions in harsh environments often fail at an extremely high rate and lead to high maintenance costs in maintaining the mechanical system due to limits associated with the materials required to construct the sensors. In addition, conventional sensors typically require a variety of materials bonded together, and the varying limits associated with the varying materials may further complicate sensor design, and may also lead to increased failure rates due to some required materials having low environmental condition limits.

Conventional methods of dealing with the above issues typically involve acknowledging the limits associated with a sensor, the lifetime of the sensor, and that its lifetime and measurement capabilities are limited by the environment within which it is configured. In some systems, conventional methods of dealing with the above issues typically involve fixing a sensor in a location remote from the desired sensing location and estimating operating conditions at the desired sensing location based on the data collected from the remote position.

Consequently, there is a continuing need for improved sensors and sensing methods to address these and other difficulties with conventional sensor technology.

SUMMARY OF THE INVENTION

Embodiments of the invention are generally directed to a sensor and a sensing method, in which signals communicated over one or more wires are monitored such that environmental conditions may be measured based at least in part on characteristics of the communicated signals.

Consistent with some embodiments of the invention, a sensor configured to sense one or more environmental conditions is provided. The sensor comprises a housing having a first and second end, and includes a diaphragm proximate the first end and coupled to the housing. An attachment plate may be coupled to the housing, such that an interior is defined within the housing and between the diaphragm and the attachment plate. A wire may be coupled in tension between the attachment plate and the diaphragm. The wire may exhibit varying ultrasonic signal transmission characteristics as the tension between the wire and the diaphragm changes.

In some embodiments, one or more environmental conditions may act upon the sensor, thereby exerting a force on the diaphragm of the sensor. For example, pressure of the environment in which the sensor is positioned may cause the diaphragm to deflect. In response to the force acting upon the diaphragm, the tension of the wire coupled to the diaphragm may vary. Based at least in part on the varying tension of the wire, transmission characteristics of the wire may change.

In some embodiments, a controller may be operatively coupled to the wire and configured to determine the varying transmission characteristics of the wire. The controller may be further configured to determine environmental conditions based at least in part on the determined varying transmission characteristics. In some embodiments, the controller may be further configured to output a readout signal, where the readout signal includes information based at least in part on the determined environmental conditions.

In further embodiments, the sensor may include a second wire coupled to the attachment plate and configured in the interior, and the second wire may not be tensioned between the attachment plate and the diaphragm. In these embodiments, the second wire may exhibit varying signal transmission characteristics as one or more environmental conditions act upon the sensor. For example, the temperature of the environment in which the sensor is positioned may cause the second wire to exhibit varying signal transmission characteristics. In some embodiments, the controller may be operatively coupled to second wire and configured to determine the varying transmission characteristics of the second wire. In some embodiments, the controller may be further configured to determine environmental conditions based at least in part on the determined varying transmission characteristics of the second wire.

In addition, there are provided methods of sensing an environmental condition consistent with embodiments of the invention. In some embodiments, a pressure may be measured with a sensor. The sensor includes a housing having a first and second end, and a diaphragm proximate the first end and coupled to the housing. An attachment plate may be coupled to the housing such that an interior is defined within the housing and between the diaphragm and the attachment plate. A wire may be coupled in tension between the attachment plate and the diaphragm. The method comprises transmitting an ultrasonic signal through the wire and measuring a force caused by a pressure on the diaphragm of the sensor by sensing an ultrasonic signal from the wire and determining a tension on the wire based upon a characteristic of the sensed ultrasonic signal.

In some embodiments, the sensor may be further configured with a second wire coupled to the attachment plate and configured in the interior, such that the second wire is not tensioned between the attachment plate and the diaphragm. The method may further comprise transmitting a second ultrasonic signal through the second wire. A temperature associated with the sensor may be measured by sensing an ultrasonic signal from second wire and determining the temperature based on a characteristic of the ultrasonic signal sensed in the second wire.

In some embodiments consistent with the invention, a sensor may be positioned proximate a sensing location, and the sensor may be utilized to measure environmental conditions associated with the sensing location, including pressure, temperature, vibration, and/or strain. In one aspect of some embodiments, the sensor may include a measuring surface, where the measuring surface may be positioned such that one or more environmental conditions of the sensing location may interact the measuring surface. Additionally, the sensor may include one or more wires coupled to the measuring surface, where the wires may transmit ultrasonic signals. One or more ultrasonic signals may be transmitted through the wires, and one or more ultrasonic signals may be sensed through the wires. In some embodiments, a controller may be configured to analyze the one or more sensed ultrasonic signals, and a measurement of one or more environmental conditions of the sensing location may be determined based at least in part on the analysis of the one or more sensed ultrasonic signals. In some embodiments, the analysis of the one or more sensed ultrasonic signals may include comparing the one or more sensed ultrasonic signals to the one or more reference ultrasonic signals stored in the controller. In some embodiments, the reference ultrasonic signals may include one or more of the transmitted ultrasonic signals. In some embodiments, the reference ultrasonic signals may include one or more of the sensed ultrasonic signals.

Hence, using the disclosed systems and methods of the invention, improvements may be realized in sensing technology and especially in regard to sensing applications in harsh sensing environments. These and other advantages will be apparent in light of the following figures and Detailed Description.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of embodiments of the invention. The specific design features of embodiments of the invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes of various illustrated components will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments may have been enlarged or distorted related to others to facilitate visualization and clear understanding.

DETAILED DESCRIPTION

Embodiments of the invention are generally directed to a sensor and a sensing method, in which signals communicated over one or more wires are monitored such that environmental conditions may be measured based at least in part on characteristics of the communicated signals, where the environmental conditions include pressure, force, temperature, strain, and/or vibration.

In some embodiments consistent with the invention, a pressure sensor may comprise a housing having a first and second end. A diaphragm may be coupled to the housing, proximate the first end, and an attachment plate may be coupled to the housing, such that an interior is defined within the housing and between the diaphragm and the attachment plate. A wire may be coupled in tension between the attachment plate and the diaphragm, such that the wire exhibits a varying ultrasonic signal transmission characteristic as the tension between the attachment plate and the diaphragm changes.

As discussed above, conventional sensors used in harsh sensing environments typically fail at a high rate due to limits associated with the materials required to design the conventional sensors. Embodiments of the invention, however, overcome the material limits of conventional sensors. Sensors consistent with embodiments of the invention may be constructed of a single material, thereby minimizing thermal strains and challenges associated with bonding dissimilar materials. Moreover, embodiments of the present invention may be constructed using a variety of materials, thereby allowing selection of one or more construction materials based on material properties. Suitable materials for housings, diaphragms, and attachment plates include, for example metals and alloys such as stainless steel alloys, titanium and titanium alloys, superalloys (e.g. Inconel® variations), and other materials suitable for harsh environments (i.e. high temperature, high pressure, and/or high vibration environments). Suitable materials for wires include, for example metals and alloys such as stainless steel alloys, titanium and titanium alloys, superalloys (e.g. nickel, cobalt, nickel-iron superalloys, for example Inconel® variations), and other materials suitable for harsh environments (i.e. high temperature, high pressure, and/or high vibration). It will be appreciated that housings, diaphragms, attachment plates and wires in a single sensor design may all be constructed of the same material in some embodiments, while in other embodiments, heterogeneous materials may be used for some of these components.

Embodiments consistent with the present invention may utilize ultrasonic signals, and measure environmental conditions based at least in part on the ultrasonic signals. Ultrasonic signals may generally be transmitted over a large distance, which enables equipment associated with an ultrasonic sensor to be located remote from the desired sensing location, while still being able to measure environmental conditions at the desired sensing location by utilizing sensors consistent with embodiments of the invention positioned in the desired sensing location.

In some embodiments of the invention, the sensor may measure the length change of the tensioned wire. The length of the wire may be found by measuring a varying ultrasonic signal transmission characteristic of the wire. In some embodiments, the varying ultrasonic signal transmission characteristic may include phase of an ultrasonic signal, amplitude of an ultrasonic signal, frequency of an ultrasonic signal, and/or propagation delay of an ultrasonic signal. Consistent with embodiments of the invention, an environmental condition monitored by the sensor may be measured by measuring the difference in one or more of the ultrasonic signal transmission characteristics.

For example, in some embodiments, the sensor may be configured at a sensing location such that the diaphragm separates a pressure difference. In this exemplary embodiment, a force may act on the diaphragm due to the pressure difference across the diaphragm. In this example, the force may deflect the diaphragm in the direction of lower pressure, and the tension of the wire may increase or decrease corresponding to the direction of deflection of the diaphragm. In this example, an ultrasonic signal transmission characteristic may vary as the tension of the wire varies. In this example, an ultrasonic signal may be transmitted through the wire, and a sensed ultrasonic signal may be compared to a reference ultrasonic signal to determine the variance in the ultrasonic signal transmission characteristic. Furthermore, the pressure in the sensing location may be determined based at least in part on the determined variance between the sensed ultrasonic signal transmission characteristic and the reference ultrasonic signal transmission characteristic.

Embodiments consistent with the present invention may sense pressure and temperature of the sensing environment at the sensing location. In some embodiments, the wire may exhibit a varying resistance as a temperature associated with the pressure sensor changes. In some embodiments, a pressure sensor may include a second wire coupled to the attachment plate and configured in the interior, and the second wire may not be tensioned between the diaphragm and the attachment plate. In some embodiments, the second wire may exhibit a varying ultrasonic signal transmission characteristic as the temperature associated with the pressure sensor changes. In embodiments consistent with the present invention, an ultrasonic signal may be transmitted through the second wire, and a second ultrasonic signal sensed on the second wire may be analyzed to determine a variance of an ultrasonic signal transmission characteristic of the second wire as compared to a reference ultrasonic signal transmission characteristic.

Systems and methods consistent with various aspects of the invention may be utilized to transmit and sense ultrasonic signals. In some embodiments, an ultrasonic signal may be transmitted through the wire, and the sensed ultrasonic signal may include a reflection or echo of the transmitted ultrasonic signal. In some embodiments, an ultrasonic signal may be transmitted through the wire, and the sensed ultrasonic signal may include a portion of the transmitted ultrasonic signal. In some embodiments, an ultrasonic signal may be transmitted through the wire, and the sensed ultrasonic signal may be a modification of the transmitted ultrasonic signal. In other embodiments, a wire may have a first end and a second end, and an ultrasonic signal may be transmitted through the wire at the first end, and an ultrasonic signal may be sensed through the wire at a second end, and the sensed ultrasonic signal may be based at least in part on the transmitted ultrasonic signal. The frequency of a transmitted ultrasonic signal may vary in different embodiments, although in many embodiments, a transmitted ultrasonic signal of between about 100 KHz and about 10 MHz, or more particularly a signal of between about 1 MHz and about 5 MHz may be used.

As the sensors may be positioned to measure environmental conditions in sensing locations typically considered harsh sensing environments, materials suitable for harsh environments may be utilized in various combinations to construct sensors consistent with some embodiments of the invention. Moreover, the materials and configurations of wires consistent with embodiments of the invention may comprise similarly suitable materials. In addition, wires consistent with embodiments of the invention generally include material properties making the wires suitable for transmission of ultrasonic signals, including for example, various metals and alloys. Furthermore, while some embodiments include wires comprising a uniform construction, other embodiments may include wires advantageously comprising braided constructions, where braided constructions may provide higher tensile strengths in some embodiments. Uniformly constructed and braided wires comprising diameters between about 0.001 inches and 0.50 inches, or more particularly diameters between 0.005 inches and 0.25 inches may be used. The cross-sectional shapes of wires may vary in different embodiments, although in many embodiments, the cross-sectional shapes in many embodiments may include shapes that may be configured to transmit ultrasonic signals consistent with embodiments of the invention, including, for example substantially circular cross-sectional wires, substantially rectangular cross-sectional wires, substantially ribbon cross-sectional wires, etc.

Turning to the drawings, where like numbers denote like parts throughout the several views,FIG. 1illustrates a sensor10consistent with some embodiments of the invention. Sensor10may include a housing12having a first end14and a second end16. A diaphragm18may be coupled to the housing12proximate the first end14. An attachment plate20may be coupled to the housing12proximate the second end16. Sensor10may include a wire22coupled to attachment plate20. In embodiments consistent with the invention, the diaphragm18may be coupled to the housing12, including the diaphragm18being integral to, attached to, fastened to, welded to, soldered to, and/or brazed to the housing12.

FIG. 2illustrates a cross sectional view of sensor10consistent ofFIG. 1. Consistent with some embodiments of the invention, diaphragm18and attachment plate20may be coupled to housing12such that interior30is defined therebetween. Securing member32may be coupled to diaphragm18, as shown, and may extend from diaphragm18into interior30. As shown inFIG. 2, consistent with some embodiments of the invention, a first portion34of wire22may be coupled to the attachment plate20at a first end and to the diaphragm18utilizing the securing member32, and a second portion36of wire22may be coupled to the attachment plate20at a second end and also to the diaphragm18utilizing the securing member32, such that portions34,36may both be tensioned between attachment plate20and diaphragm18. Furthermore, the securing member32may comprise a hook, eyelet, set screw, and/or other securing member configured to couple wire22in tension between the diaphragm18and the attachment plate20.

In some embodiments, the wire22may be tensioned between the diaphragm18and attachment plate20such that the tension of wire22may vary in response to a deflection of the diaphragm. In some embodiments, at least a portion of wire22may be initially tensioned at a desired force between the diaphragm18and the attachment plate20. For example, in some embodiments, at least a portion of wire22may be initially tensioned from about 1 pound to about thirty pounds, or more particularly at least a portion of wire22may be initially tensioned from about 10 pounds to 13 pounds. In some embodiments, the initial tension applied to wire22may be determined based at least in part on properties of the materials used to form the wire22, the diaphragm18, the attachment plate20, and/or the housing12.

FIG. 3illustrates a cross-sectional a sensor and further illustrates some aspects of a sensor40consistent with some embodiments of the invention. As shown inFIG. 3, sensor40includes housing42, a diaphragm44coupled to the housing proximate a first end of housing42, and an attachment plate46coupled to the housing proximate a second end of housing42such that interior48may be defined in sensor40by housing42, diaphragm44, and attachment plate46. Moreover, wire50may be coupled in tension between diaphragm44and attachment plate46within interior48. Furthermore, force52may act upon diaphragm44, such that diaphragm44may deflect in response to force52. As such, the tensional force on wire50between diaphragm44and attachment plate46may vary in response to the deflection of diaphragm44due to force52. Transmitting circuitry54may be operatively coupled to wire50, such that transmitting circuitry54may be configured to transmit an ultrasonic signal through wire50. Receiving circuitry56may be operatively coupled to wire50, such that receiving circuitry may be configured to sense an ultrasonic signal from wire50. InFIG. 3, wire58may be configured in interior48, and wire58may not be tensioned between the diaphragm44and the attachment plate46. Wire58may be operatively coupled to transmitting circuitry54, such that transmitting circuitry may be configured to transmit an ultrasonic signal through wire58. Receiving circuitry56may be operatively coupled to wire58, such that receiving circuitry may be configured to sense an ultrasonic signal from wire58.

As discussed above, diaphragm44may deflect when acted upon by force52of sensing location60in which sensor40is configured. As such, in response to a deflection of diaphragm44caused by an environmental condition present in the sensing location60in which sensor40may be placed, the tensional force on wire50may vary. Environmental conditions including pressure, temperature, vibration, and strain may cause a force to act upon diaphragm44, thereby causing a deflection. As the tensional force on wire50varies in response to the deflection of diaphragm44, an ultrasonic signal transmission characteristic of wire50may vary based at least in part on the varying tensional force. Transmitting circuitry54may transmit an ultrasonic signal through wire50, and receiving circuitry56may sense an ultrasonic signal transmitted through wire50. As shown inFIG. 3, transmitting circuitry54and receiving circuitry56may be operatively connected to controller62, which includes processor64, memory66, and application68resident in memory66. Controller62may be configured to control transmitting circuitry54and receiving circuitry56, and/or transmitting circuitry54and receiving circuitry56may be configured as one or more interfaces of controller62.

In some embodiments consistent with the invention, an ultrasonic signal sensed using receiving circuitry56may be compared to a reference ultrasonic signal to determine a variance of one or more ultrasonic signal transmission characteristics of wire50that varied as a result of a deflection of diaphragm44. Furthermore, in some embodiments, a measurement of an environmental condition of sensing location60may be generated based at least in part on the determined ultrasonic signal transmission characteristic variance of wire50.

FIG. 3illustrates a sensor40consistent with embodiments of the invention configured to measure an environmental condition in sensing location60. In some embodiments, at least a portion of interior48may be pressurized to be above atmospheric pressure, pressurized to be about atmospheric pressure, or depressurized to be below atmospheric pressure. In these embodiments, the pressurization or depressurization of a portion of interior48may cause a pressure differential between sensing location60and interior48, such that a force may act on diaphragm44. For example, if sensor40is placed in a sensing location60having a pressure differential as compared to interior48, the pressure differential between interior48and sensing location60may cause a force52to act upon diaphragm44. For example, if the pressure of interior48were configured to be about atmospheric pressure, and the pressure of sensing location60were higher than the pressure of interior48, diaphragm44may deflect into interior48. In this example, as diaphragm44deflects into interior48due to the higher pressure environment of sensing location60, the tension of wire50may vary, and in response to the varying tension of wire50, an ultrasonic transmission characteristic of wire50may vary.

In some embodiments, controller62may be operatively coupled to wire50, and configured to transmit an ultrasonic signal through wire50, and the controller may also be configured to sense an ultrasonic signal transmitted through wire50. In some embodiments consistent with the invention, controller62may be configured to determine an ultrasonic signal transmission characteristic of wire50based at least in part on an ultrasonic signal sensed from wire50. In embodiments consistent with the invention ultrasonic signal transmission characteristics of wire50include phase of an ultrasonic signal, amplitude of an ultrasonic signal, frequency of an ultrasonic signal, and propagation delay of an ultrasonic signal. In some embodiments, controller62may be further configured to determine a deflection of diaphragm44based at least in part on a determined ultrasonic signal transmission characteristic. In some embodiments, controller62may determine an environmental condition of sensing location60based at least in part on the determined deflection of diaphragm44. In some embodiments, controller62may determine a pressure of sensing location60based at least in part on the variance of an ultrasonic signal transmission characteristic of wire50and/or the deflection of diaphragm44.

Referring toFIG. 3, controller62may transmit an ultrasonic signal through wire50, and controller62may further sense an ultrasonic signal transmitted through wire50. In some embodiments, the sensed ultrasonic signal may be based at least in part on the transmitted ultrasonic signal, but due to the environmental conditions of sensing location60acting on sensor40, the sensed ultrasonic signal may include signal characteristics that vary from the transmitted ultrasonic signal characteristics. Controller62may compare the ultrasonic signal characteristics of the transmitted ultrasonic signal and the sensed ultrasonic signal to determine a varying ultrasonic signal transmission characteristic of wire50.

As is generally known in the field, signal processing methods including filtering, demodulation, and Hilbert transform processing methods may be used to determine one or more ultrasonic signal transmission characteristics. In some embodiments, controller62may perform one or more signal processing operations on the ultrasonic signal sensed on wire50to determine one or more ultrasonic signal transmission characteristics of wire50as well as the variance of one or more ultrasonic signal transmission characteristics of wire50.

In some embodiments, an ultrasonic signal may be sensed on wire50to determine additional environmental conditions of sensing location60, including temperature, strain, and vibration. An ultrasonic signal may be sensed on wire50, and the resistance of the wire may be determined based at least in part on the sensed ultrasonic signal. In some embodiments, a temperature associated with the sensor40and/or sensing location60may be determined based at least in part on the determined resistance of wire50.

As shown inFIG. 3, in some embodiments, sensor40may include wire58positioned in interior48. As compared to wire50, wire58may be substantially proximate to and/or co-located in relation to wire50, but wire58may not be coupled in tension between diaphragm44and attachment plate46. As such, ultrasonic transmission characteristics of wire58may not vary in response to a deflection of diaphragm44. In these embodiments, an ultrasonic signal may be transmitted through wire58, and an ultrasonic signal may be sensed through wire58, and ultrasonic signal sensed through wire58may be used to determine a varying ultrasonic transmission characteristic of wire58. In some embodiments, the determined varying ultrasonic transmission characteristic may be used to determine one or more environmental conditions of sensing location60, such as temperature, vibration, and strain.

In addition, as wire50may be tensioned between diaphragm44and attachment plate46, and wire58may not be tensioned between diaphragm44and attachment plate46, the ultrasonic signal sensed on wire58may be used as a reference signal by the controller62to be compared to the ultrasonic signal sensed on wire50. In some embodiments, the variance of an ultrasonic transmission characteristic of wire50and wire58may differ only with respect to the variance attributable to the varying tension of wire58caused by the deflection of diaphragm44. As such, in these embodiments, the variance of an ultrasonic transmission characteristic attributable to the varying tension of wire50caused by the deflection of diaphragm44may be determined by comparing the ultrasonic signal sensed from wire50to the ultrasonic signal sensed from wire58. In addition, in these embodiments, an environmental condition of sensing location60may be determined based at least in part on the deflection of diaphragm44corresponding to the environmental condition. For example, if an environmental condition of sensing location60included a pressure higher than interior48, the force caused by the pressure differential may cause a deflection of diaphragm44into interior48. In response, the tensional force on wire50may vary, thereby causing the transmission path length of wire50to shorten. However, in this example, the high pressure environmental condition of sensing location60may not be the only environmental condition causing the transmission path length of wire50to change. For example, the temperature of sensing location60and/or a temperature associated with sensor40may cause thermal expansion of wire50, thereby increasing the transmission path length of wire50. In order to separate the transmission path length change of wire50due to the pressure differential from the temperature of sensing location60, the ultrasonic transmission characteristic of wire58may be compared to the sensed ultrasonic transmission characteristic of wire50. In this example, the ultrasonic transmission characteristic of wire58may vary due to other environmental conditions of sensing location60, while not varying due to the pressure differential, and the variance of the ultrasonic transmission characteristic of wire50due to the deflection of diaphragm44, and therefore the pressure differential may thereby be determined.

In some embodiments, the transmission path length change of wire50due to the deflection of diaphragm44may be determined based at least in part on the determined variance of the ultrasonic transmission characteristic of wire50due to the deflection of diaphragm44. Furthermore, the deflection of diaphragm44may be determined based at least in part on the determined transmission path length change of wire50. In some embodiments, a measurement of an environmental condition of sensing location60may be determined based at least in part on the determined deflection of diaphragm44.

In some embodiments, the temperature of sensing location60may be determined based at least in part on the variance of an ultrasonic transmission characteristic of wire58. As discussed, wire58may not be coupled in tension between diaphragm44and attachment plate46, and as such, variance of an ultrasonic transmission characteristic of wire58may correspond to a thermal expansion of wire58due to a temperature associated with the sensor and/or sensing location60. For example, the path length of wire58may vary due to thermal expansion caused by the temperature of sensor40and sensing location60. In some embodiments, transmitting circuitry54may be configured to transmit a first ultrasonic signal through wire50and a second ultrasonic signal through wire58. In some embodiments, transmitting circuitry54may be configured to transmit an ultrasonic signal through wire50and wire58. Furthermore, in some embodiments, the ultrasonic signal sensed from wire50may be analyzed to determine a force on diaphragm44, and the ultrasonic signal sensed from wire58may be analyzed to determine a temperature associated with sensor and/or sensing location60.

In some embodiments, wire50may exhibit a varying resistance as a temperature associated with the sensor40and/or sensing location60changes. As such, in some embodiments, a temperature associated with the sensor40and/or sensing location60may be determined based at least in part on the varying resistance of wire50. Furthermore, in these embodiments, a pressure of sensing location60may be determined based in part on a varying ultrasonic transmission characteristic of wire50. In some embodiments, the determined pressure of sensing location60based in part on the varying ultrasonic signal transmission characteristic of wire50may be adjusted based in part on the determined temperature associated with the sensor. In some embodiments, a temperature compensated pressure measurement of sensing location60may be determined.

In some embodiments, wire58may be operatively connected to the housing42, and wire58may exhibit a varying ultrasonic signal transmission characteristic as the temperature associated with the housing42changes. In some embodiments, an ultrasonic signal may be sensed from wire58, and a varying ultrasonic signal transmission characteristic of wire58may be determined based in part on the sensed ultrasonic signal from wire58. In some embodiments, a temperature associated with the housing42may be determined utilizing the determined varying ultrasonic signal transmission characteristic of wire58.

In some embodiments, wire58may be operatively connected to the housing42, and wire58may exhibit a varying resistance as the temperature associated with the housing42changes. In some embodiments, the resistance of wire58may be determined, and a temperature associated with the housing42may be determined utilizing the determined resistance.

Referring now toFIG. 4,FIG. 4illustrates a cross-sectional view of a sensor80consistent with some embodiments of the invention. Sensor80includes a filter plate82coupled to a wire84, where the wire may be configured to transmit ultrasonic signals. As shown inFIG. 4, sensor80may further include transmitting circuitry86and receiving circuitry88operatively connected to wire84. Consistent with some embodiments of the invention, filter plate82may comprise layers of one or more materials. Wire84may be coupled to filter plate82such that filter plate82may receive an ultrasonic signal transmitted through wire84, where the received ultrasonic signal may be of a first frequency band. In some embodiments, the filter plate82may be configured to generate a reflected ultrasonic signal of a second frequency band based in part on the received ultrasonic signal, and the reflected ultrasonic signal may be transmitted through wire84. In some embodiments, the filter plate82may be configured such that the layers of filter plate82may deflect from a neutral position in response to a force acting on the filter plate82. In some embodiments, as filter plate82deflects due to a force, the spacing between the layers, the strain on each layer, and/or the resonant frequence of the filter plate82may vary. As such, the filter plate82may filter a frequency range of the received ultrasonic signal, such that the frequency range of the reflected ultrasonic signal may be a subset of the received ultrasonic signal.

As shown, wire84may be operatively coupled with ultrasonic transmitting86and receiving circuitry88such that an ultrasonic signal may be transmitted through wire84, and the reflected ultrasonic signal may be sensed on wire84. Not shown inFIG. 4, in further embodiments a controller may be operatively coupled to the transmitting and receiving circuitry86,88such that the controller may analyze the sensed reflected ultrasonic signal. In some embodiments, the controller may be configured to analyze the sensed reflected ultrasonic signal to determine frequency bands filtered from the sensed reflected ultrasonic signal as compared to the transmitted ultrasonic signal. In some embodiments, the controller may determine a measurement of the force on filter plate88based at least in part on the determined frequency bands filtered from the sensed reflected ultrasonic signal.

In some embodiments consistent with sensor80ofFIG. 4, the filter plate82may be configured to reflect the received ultrasonic signal, and the change in frequency of the reflected ultrasonic signal may be determined. The transmitting circuitry may transmit an ultrasonic signal centered on a modulation frequency. Depending upon the spacing between the layers of filter plate82and the strain on layers of filter plate82due to a force, the resonant frequency of the filter plate82may vary, and the filter plate82may filter the received ultrasonic signal. Due to the change in resonant frequency of the filter plate82, the filter plate82may remove spectral content of a given frequency band. The reflected ultrasonic signal may include a frequency band corresponding to the frequencies not filtered by filter plate82. In some embodiments, a pressure differential may cause a force on filter plate82, and as the pressure increases, the spacing of the layers of filter plate88may change, causing the resonant frequency of the filter plate82to change, thereby filtering a varying frequency band of the received ultrasonic signal based at least in part on the pressure on filter plate82. The controller may measure the change in frequency between the transmitted ultrasonic signal and the sensed ultrasonic signal and calculate the corresponding change in spacing of the layers of the filter plate88, which may correspond to the pressure differential acting on the filter plate82.

In some embodiments, a sensor consistent with some embodiments may include a filter plate, as shown inFIG. 4and a wire coupled to the filter plate. In some embodiments, transmitting an ultrasonic signal through and sensing of an ultrasonic signal from the wire may be performed at a common end, such that a pulse/echo ultrasonic signal method may be utilized. As such, in these embodiments, the transmitting and receiving circuitry may be operatively connected to a common end of the wire, and/or the transmitting and receiving circuitry may comprise a combined transceiver circuitry. In these embodiments, an ultrasonic signal may be transmitted through the wire and reflected by the filter plate to the receiving/transceiving circuitry.

Referring now toFIG. 5,FIG. 5illustrates a sensor100consistent with some embodiments of the invention. Sensor100is positioned to measure one or more environmental conditions of sensing location102. Sensor100includes a housing104, the housing including an interior106. As shown inFIG. 5, interior106may be in fluid communication with sensing location102, such that environmental conditions of sensing location102may exert force on the surface of housing104defining interior106. Sensor100may include wire108at least partially connected to housing104. At least a portion of wire108may be coupled in tension to housing104, such that wire108may exhibit a varying ultrasonic signal transmission characteristic as a force acts on housing104. In some embodiments, wire108may be operatively coupled to transmitting circuitry110such that an ultrasonic signal may be transmitted through wire108, and wire108may be operatively coupled to receiving circuitry112such that an ultrasonic signal may be sensed from wire108. Controller114may be operatively coupled to transmitting circuitry110and receiving circuitry112, such that controller114may analyze the ultrasonic signal sensed on wire108to determine a varying ultrasonic signal transmission characteristic of wire108.

FIG. 6illustrates a cross-sectional view of a sensor120consistent with some embodiments of the invention. As shown inFIG. 6, sensor120includes a housing122having a diaphragm124coupled to housing122proximate a first end and an attachment plate126coupled to housing122proximate a second end, such that interior128may be defined by housing122, diaphragm124, and attachment plate126. As shown inFIG. 6, sensor120includes wire130coupled in tension between diaphragm124and attachment plate126. Furthermore, sensor120may include wire132, which may be coupled in tension between diaphragm124and attachment plate126. In some embodiments, wire132may be tensioned such that wire132exhibits a varying resistance as a temperature associated with sensor120changes, and the resistance of wire132may be analyzed to determine the temperature associated with sensor120.

Alternatively, wire132may be operatively connected to diaphragm124and may not be coupled in tension between attachment plate126and diaphragm124. In some embodiments, wire132may exhibit a varying ultrasonic signal transmission characteristic as the temperature associated with the diaphragm124changes. In some embodiments, an ultrasonic signal may be sensed from wire132, and the ultrasonic signal sensed from wire132may be analyzed to determine the varying ultrasonic signal transmission characteristic of wire132. In some embodiments, the varying ultrasonic signal transmission characteristic of wire132may be analyzed to determine a temperature associated with the diaphragm124. In some embodiments, wire132may exhibit a varying resistance as the temperature associated with the diaphragm124changes. In some embodiments, the resistance of wire132may be determined, and a temperature associated with the diaphragm124may be determined based at least in part on the determined resistance of wire132.

FIG. 7illustrates a cross-sectional view of a sensor140consistent with some embodiments of the invention. As shown inFIG. 7, sensor140includes a housing142, a diaphragm144coupled to the housing, and an attachment plate146coupled to the housing. Sensor140includes a wire148coupled in tension between the diaphragm144and the attachment plate146. Furthermore, sensor140includes wire150operatively connected to housing142, and configured at least partially around housing142. As shown inFIG. 7, in some embodiments, wire150may be connected to the exterior of housing142, and in other embodiments, wire150may be positioned in interior152and connected to the interior surface of housing142. In some embodiments, wire150may exhibit a varying ultrasonic signal transmission characteristic as a temperature associated with sensor140changes. In some embodiments, wire150may exhibit a varying resistance as a temperature associated with sensor140changes.

FIG. 8illustrates a cross sectional view of a sensor160having a housing162, a diaphragm164, and an attachment plate166. Sensor160includes wire168, and wire168includes reflection points170,172,174,176,178,180,182,184. A first portion of wire168may be coupled in tension between the diaphragm164and the attachment plate166, where reflection point170and reflection point172approximately define the first portion of wire168.

In some embodiments, the reflection points170,172,174,176,178,180,182,184may be configured to each reflect an ultrasonic signal transmitted through wire168, such that a reflection based at least in part on the transmitted ultrasonic signal may be reflected from the reflection points170,172,174,176,178,180,182,184back to the end of wire168from which the transmitted ultrasonic signal was introduced. As such, a reflected signal from each reflection point170,172,174,176,178,180,182,184may be sensed on the wire168, the sensed reflected signals may be analyzed, and measurements associated with the sensor160may be determined based at least in part on the sensed reflected signals.

In some embodiments, a pressure associated with sensor160may be determined. As described previously, a pressure associated with the sensor160and/or a sensing location in which the sensor160may exert a force on diaphragm164of sensor160, which may cause a deflection of diaphragm164. In response to the deflection of diaphragm164, the tension of the first portion of wire168coupled in tension between diaphragm164and attachment plate166may thereby change. An ultrasonic signal may be transmitted through wire168, reflection point170may reflect a first reflected signal, and reflection point172may reflect a second reflected signal. A controller operatively connected to wire168may sense the first reflected signal and the second reflected signal, and the controller may analyze the sensed reflected signals. As such, the tension of the first portion, the deflection of the diaphragm, the force acting on the diaphragm, and/or the pressure associated with the sensor and/or sensing location may be determined based at least in part on the analyzed sensed reflected signals.

Additional measurements such as a temperature associated with the diaphragm164, a temperature associated with the housing162, and/or a temperature associated with the first portion (i.e., the tensioned portion approximately defined by reflection points170and172) may be determined by analyzing the reflected signals from reflection points174,176,178,180,182, and184included on wire168. Where this second portion of wire168configured in interior186may be defined as the length of wire168located from approximately reflection point172to reflection point184, and the second portion of wire may not be coupled in tension. These additional measurements may be extremely valuable in not only providing measurements associated with the sensor and/or sensing location, but also compensating for additional environmental condition factors in measurements of the sensor. Additional environmental condition factors include for example, expansion of the housing162due to thermal expansion (e.g., analyzing the sensed reflected signals associated with reflection points178and180), expansion of the wire168due to thermal expansion (e.g., analyzing the sensed reflected signals associated with reflection points174and176), and/or change of stiffness/rigidity of the diaphragm164due to temperature (analyzing the sensed reflected signals associated with reflection points182and184).

As such, in some embodiments, sensor160may determine a temperature associated with the housing162. An ultrasonic signal may be transmitted through wire168, reflection point178may reflect a third reflected signal, and reflection point180may reflect a fourth reflected signal. A controller operatively connected to wire168may sense the third reflected signal and the fourth reflected signal, and the controller may analyze the sensed third and fourth reflected signals. As such, a temperature associated with the housing162, sensor160and/or the sensing location may be determined based at least in part on the analyzed sensed third and fourth reflected signals. Moreover, determining a pressure associated with the sensor160and/or a sensing location may be based at least in part on the sensed third and fourth reflected signals, such that the determined pressure measurement may include compensation for the temperature determined using the third and fourth reflected signals.

In some embodiments, sensor160may determine a temperature associated with the first portion (i.e. tensioned portion) of wire168. An ultrasonic signal may be transmitted through wire168, reflection point174may reflect a fifth reflected signal, and reflection point176may reflect a sixth reflected signal. A controller operatively connected to wire168may sense the fifth reflected signal and the sixth reflected signal, and the controller may analyze the sensed fifth and sixth reflected signals. As such, a temperature associated with the first portion of wire168, sensor160and/or the sensing location may be determined based at least in part on the analyzed sensed fifth and sixth reflected signals. Moreover, determining a pressure associated with the sensor160and/or a sensing location may be based at least in part on the sensed fifth and sixth reflected signals, such that the determined pressure measurement may include compensation for the temperature determined using the fifth and sixth reflected signals.

In some embodiments, sensor160may determine a temperature associated with the diaphragm164. An ultrasonic signal may be transmitted through wire168, reflection point182may reflect a seventh reflected signal, and reflection point184may reflect an eighth reflected signal. A controller operatively connected to wire168may sense the seventh reflected signal and the eighth reflected signal, and the controller may analyze the sensed seventh and eighth reflected signals. As such, a temperature associated with the diaphragm164, sensor160and/or the sensing location may be determined based at least in part on the analyzed seventh and eighth reflected signals. Moreover, determining a pressure associated with the sensor160and/or a sensing location may be based at least in part on the sensed seventh and eighth reflected signals, such that the determined pressure measurement may include compensation for the temperature determined using the seventh and eighth reflected signals, such that the determined pressure may include compensation for a change in stiffness/rigidity of the diaphragm164.

Referring now toFIG. 9, a cross-sectional view of a sensor190consistent with some embodiments of the invention is provided. Sensor190includes a housing192having a first end194and a second end196. As shown inFIG. 9, sensor190includes a first diaphragm198coupled to the housing192proximate the first end194and a second diaphragm200coupled to the housing192proximate the second end196such that an interior192may be defined between the housing192, the first diaphragm198, and the second diaphragm200. Sensor190further includes a wire204coupled in tension between the first diaphragm198and the second diaphragm200, such that the wire204exhibits a varying characteristic as the tension between the first diaphragm198and the second diaphragm200changes. In some embodiments, the varying characteristic includes resistance of wire204, and in some embodiments, the varying characteristic includes an ultrasonic signal transmission characteristic. As discussed above with regard to various embodiments of the invention, an ultrasonic signal may be transmitted through wire204, and an ultrasonic signal may be sensed through wire204. Moreover, sensor200may be positioned in a sensing location206, such that environmental conditions including pressure, temperature, vibration, and strain may exert force on sensor190, and particularly on the first diaphragm198and the second diaphragm200. In some embodiments, a measurement of one or more environmental conditions of a sensing location206may be determined by analyzing the ultrasonic signal sensed from wire204. Moreover, embodiments including a first diaphragm198and a second diaphragm200may be configured to compensate for one or more environmental conditions. For example, sensor190may be configured to determine a pressure of a sensing location, and the dual diaphragms of sensor190may compensate for vibration in the sensing location because each diaphragm may be exposed to the vibration.

Referring toFIG. 10, a cross sectional view of a sensor220consistent with some embodiments of the invention is provided. Sensor220includes a housing222, a diaphragm224, and an attachment plate226, such that an interior228may be defined. Sensor220may include a wire230, where at least a portion of wire230may be coupled in tension between the diaphragm224and the attachment plate226and positioned in interior228. As discussed above, one or more ultrasonic signal transmission characteristics of wire230may vary as the tension of the portion of wire230coupled in tension between the diaphragm224and the attachment plate230changes. As shown inFIG. 10, sensor220may include transmitting and receiving circuitry232(i.e. transceiving circuitry) operatively connected to wire230. Transceiving circuitry232may comprise transmitting circuitry and receiving circuitry operatively connected to a common end of wire230. In other embodiments, transceiving circuitry232may comprise transmitting and receiving circuitry commonly configured together.

In embodiments including a common transmitting and receiving end, such as the sensor shown inFIG. 10, a pulse/echo transmitting and sensing method may be utilized. In these embodiments, an ultrasonic signal may be transmitted through wire230, and an ultrasonic signal may be sensed from wire230, where the sensed ultrasonic signal may comprise an echo of the transmitted ultrasonic signal. As such, analysis of the sensed ultrasonic signal to determine a pressure measurement associated with a force acting on diaphragm224may include comparing the transmitted ultrasonic signal to the sensed echo. As the ultrasonic signal transmission characteristics of wire230may vary as the tension of the tensioned portion of wire230changes in response to the force on the diaphragm224, the transmitted ultrasonic signal may include one or more signal characteristics that differ from the sensed echo. The transmitted ultrasonic signal and the sensed echo may therefore be analyzed to determine one or more signal characteristics that vary between the transmitted ultrasonic signal and the sensed echo, and may therefore determine one or more ultrasonic signal transmission characteristics of wire230that varied in response to the change in tension of the tensioned portion of wire230.

Based at least in part on the determined variance of at least one ultrasonic signal transmission characteristic of wire230, a measurement of the pressure associated with the force acting on the diaphragm224may be determined. As such, some embodiments, a sensor utilizing a pulse/echo ultrasonic signal transmission and sensing method may determine a measurement of a pressure associated with a force acting on diaphragm224.

Referring now toFIG. 11, a cross-sectional view sensor240consistent with some embodiments of the invention is provided. Sensor240includes a housing242having a first end and a second end, a diaphragm244coupled to the housing242proximate the first end, and an attachment plate246coupled to the housing242proximate the second end, such that an interior is defined by the housing242, the diaphragm244and the attachment plate246. Sensor240includes wire248, where wire248includes a portion250coupled in tension between the diaphragm244and attachment plate246. Wire248includes a plurality of reflection points252uniformly spaced along portion250. Reflection points252include a resonant frequency such that when an ultrasonic signal comprising a frequency band including the resonant frequency may be transmitted through wire248, the reflection points252may reflect a signal comprising the resonant frequency. The resonant frequency of reflection points252varies as the tension of portion250changes. In some embodiments, an ultrasonic signal comprising a desired wavelength may be transmitted through wire248, and reflection points252are uniformly spaced along portion250at a distance comprising half the wavelength of the transmitted ultrasonic signal. In these embodiments, as the reflection points252are uniformly spaced half the wavelength of the transmitted ultrasonic signal, the reflected signal from each reflection point252will be in phase, because each reflected signal will be reflected half a wavelength apart and each reflected signal reflected from a reflection point252positioned further along the portion250will travel half a wavelength further, such that a combined reflected signal comprising the resonant frequency of the reflection points252may be sensed on wire248. In response to a change in tension, the spacing between the reflection points252may change, and as the uniform spacing changes, the resonant frequency of the reflection points252may change.

As described with regard to measuring a pressure of a sensing location, a pressure may exert a force on diaphragm244, thereby causing a deflection of diaphragm244. In response to the deflection of diaphragm244, the tension of portion250may change. In some embodiments, in response to the change in tension of portion250, the uniform spacing between the reflection points252may change, such that the resonant frequency of the reflection points252may change. As such, in these embodiments, the pressure associated with the force on diaphragm244may be measured based at least in part on the resonant frequency of the reflection points252. To determine the pressure, an ultrasonic signal may be transmitted through wire x248. The transmitted ultrasonic signal comprises a frequency band, where the frequency band includes a range of frequencies possible for the resonant frequency of the reflection points252. As diaphragm244deflects in response to the force caused by the pressure, the tension of portion250may change, and the resonant frequency of the reflection points252may vary. In these embodiments, depending on the pressure of the system, each reflection point252may reflect a reflected signal, and the combined reflected signal may be sensed. The combined reflected signal may be analyzed to determine a measurement associated with the pressure.

Reflection points252may comprise for example, cylindrical grooves in wire248, one or more materials deposited on wire248, one or more materials incorporated into wire248, such that the reflection points are configured to reflect a signal of a resonant frequency, where the resonant frequency of the reflected signal may vary with the tension on portion250.

Referring now toFIG. 12which provides a sensor260including a measuring surface262and a wire264at least a portion of which is coupled to the measuring surface262, such that one or more ultrasonic signal transmission characteristics of the coupled portion of wire264may vary as measuring surface262interacts with one or more environmental conditions. Sensor260further includes transceiving circuitry266operatively connected to wire264. As shown inFIG. 12, wire264includes a first reflection point268and a second reflection point270located on the portion of wire264coupled to measuring surface262, where the first reflection point268and the second reflection point270are configured to reflect a portion of an ultrasonic signal transmitted through wire264.

In some embodiments, transceiving circuitry266may transmit an ultrasonic signal through wire264. Based at least in part on the transmitted ultrasonic signal, first reflection point268may reflect a first reflected ultrasonic signal back to transceiving circuitry266, and based at least in part on the transmitted ultrasonic signal, second reflection point270may reflect a second reflected ultrasonic signal back to transceiving circuitry266. A controller operatively connected to transceiving circuitry266may analyze the first reflected signal and the second reflected signal to determine a variance in one or more signal characteristics between the first reflected signal and the second reflected signal, including for example, phase change, amplitude change, frequency change, and/or propagation delay. Based at least in part on the determined variance in the one or more signal characteristics between the first reflected signal and the second reflected signal, a variance in one or more ultrasonic signal transmission characteristics of the coupled portion of wire264may be determined. For example, the transmission path length of the tensioned portion of wire264may be determined by determining the phase change between the first reflected signal and the second reflected signal.

In some embodiments of sensors consistent with the sensor260ofFIG. 12, the portion of wire264coupled to measuring surface262may be coupled in tension to measuring surface262. In these embodiments, the tensional force on the portion of wire264coupled in tension to the measuring surface262may vary as a strain on measuring surface262changes. For example, if a force acted on measuring surface262, thereby causing a strain on measuring surface262, the tensional force of the coupled portion of wire264may vary. In some embodiments, the first reflected signal and the second reflected signal may be analyzed to determine the tension of the coupled portion of wire264. In some embodiments, a strain associated with measuring surface262may be determined based at least in part on the determined tension of the coupled portion of wire264. In addition, as the tensional force of the coupled portion of wire264may vary, the transmission path length of the tensioned portion of wire264may vary. In some embodiments, a strain associated with measuring surface262may be determined based at least in part on the determined transmission path length of the tensioned portion of wire264.

In some embodiments of sensors consistent with the sensor260ofFIG. 12, the portion of wire264coupled to measuring surface262may not be coupled in tension to measuring surface262. In these embodiments, an ultrasonic transmission path length of the coupled portion of wire264may vary as a temperature associated with the measuring surface262changes due to thermal expansion. In some embodiments, the first reflected signal and the second reflected signal may be analyzed to determine the transmission path length of the coupled portion of wire264. Based at least in part on the determined transmission path length of the coupled portion of wire264, a temperature associated with the measuring surface may be determined.

In some embodiments of sensors consistent with the sensor260ofFIG. 12, the portion of wire264coupled to measuring surface262may be coupled in tension, and the tensional force on the portion of wire264coupled in tension to the measuring surface262may vary as measuring surface262vibrates. In some embodiments, the first reflected signal and the second reflected signal may be analyzed to determine the tension of the coupled portion of wire264. Based at least in part on the determined tension of the coupled portion of wire264, the vibration of measuring surface262may be determined. The first reflected signal and the second reflected signal may be analyzed to determine the transmission path length of the coupled portion of wire264. In some embodiments, the vibration of measuring surface262may be determined based at least in part on the determined transmission path length of the coupled portion of wire264.

Additional embodiments consistent with the invention are contemplated. For example, referring toFIG. 12, the coupled portion of wire264may be coupled in tension along a first section and not coupled in tension along a second section, and may further include a third reflection point along the coupled portion. As such, in some embodiments, sensors configured to measure temperature, strain, and/or vibration are contemplated by including additional reflection points and coupled sections. Moreover, embodiments consistent with the invention may include additional portions coupled in tension and/or not coupled in tension including additional reflection points, such that multiple temperature, strain, and/or vibration measurements associated with one or more locations of one or more measuring surfaces may be determined using one or more wires. As such, in some embodiments, sensors consistent with embodiments of the invention may analyze reflected signals from a plurality of reflection points coupled to a plurality of measuring surfaces positioned to measure one or more environmental conditions of a sensing location.

Alternative embodiments not described in detail are contemplated. In some embodiments, ultrasonic signal transmission and sensing of one or more wires of a sensor consistent with embodiments of the invention may include pulse/echo ultrasonic signal methods. In one aspect consistent with some embodiments, a controller may transmit an ultrasonic signal through a wire, and the controller may sense the echo of the transmitted ultrasonic signal. In some embodiments, the controller may analyze the sensed echo of the transmitted ultrasonic signal to determine the variance between the transmitted ultrasonic signal and the sensed echo of the transmitted ultrasonic signal. Furthermore, in some embodiments, a sensor may include a thermocouple operatively connected to a controller, and the controller may be configured to sense a voltage of a signal generated by the thermocouple, and the controller may determine a temperature associated with the sensor based at least in part on the voltage of the signal generated by the thermocouple.

Furthermore,FIGS. 1-11illustrate embodiments comprising cylindrical housings; however the invention is not so limited. For example, sensors consistent with some embodiments of the invention may comprise triangular, quadragonal, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, or decagonal. Moreover, sensors consistent with embodiments of the invention may include housings wherein the interior may not be entirely encompassed by the housing, diaphragm, and attachment plate. For example, an attachment plate of some embodiments may not couple to a housing at all boundaries, such that an attachment plate may comprise a structure configured to couple one or more wires in tension between the diaphragm, but may not entirely enclose the interior.

FIG. 13is a flowchart300illustrating a sequence of operations consistent with embodiments of the sensors described above inFIGS. 1-9and sensing method of the invention. As shown inFIG. 13, a pressure associated with a sensing location (block302) may cause a force (block304) to act on a sensor consistent with embodiments of the invention. The force (block304) acting on a sensor may cause a deflection (block306) of a measuring surface in a sensor consistent with embodiments of the invention. In some embodiments, at least a portion of a wire may be coupled in tension to the measuring surface of the sensor, such that a deflection of the measuring surface may cause the tension of the tensioned portion to change in response to the deflection of the measuring surface (block308). The change in tension of the tensioned portion of the wire may cause one or more ultrasonic signal transmission characteristics of the wire to change, which may lead to differences between characteristics of a reference ultrasonic signal and a sensed ultrasonic signal. As such, the change in tension of the wire may cause a phase change of an ultrasonic signal as compared to a reference ultrasonic signal (block310). The change in tension of the wire may be measured by sensing ultrasonic signals from the wire and determining one or more characteristics of the sensed ultrasonic signal that varied due to the change in tension of the wire. In some embodiments, the phase change, amplitude change, frequency change, and/or propagation time of an ultrasonic signal sensed from the wire as compared to a reference ultrasonic signal may be used to determine the change in tension of the wire, change in path length of the wire, deflection of the measuring surface, force on the measuring surface, and/or pressure of the sensing location.

FIGS. 14-18illustrate sequences of operations consistent with sensing methods of the present invention and associated with the sensors consistent with the invention. Moreover, ultrasonic transmission circuitry, ultrasonic receiving circuitry, and/or controller may be configured to perform some operations included inFIGS. 14-18. Ultrasonic transmission circuitry, ultrasonic receiving circuitry, and controllers configured to perform one or more operations ofFIGS. 14-18may include special purpose microcontrollers, general purpose microcontrollers, general and special purpose computers, and other processing circuitry, and the sequences of operations may be implemented using software, firmware, or in dedicated hardware. Implementation of the sequences of operations disclosed in these figures in practically any combination of hardware, firmware and/or software, using either special purpose or general purpose electronic circuitry, would be well within the capabilities of one of ordinary skill in the art having the benefit of the instant disclosure.

FIG. 14is a flowchart320illustrating a sequence of operations consistent with embodiments of the invention. To measure a force, an ultrasonic signal may be transmitted through a wire of a sensor (block322). Consistent with the embodiments of the invention, the sensor may comprise a housing having a first end and second end, a diaphragm proximate the first end and coupled to the housing, an attachment plate coupled to the housing proximate the second end, such that an interior is defined within the housing and between the diaphragm and attachment plate, and a wire where at least a portion of the wire may be coupled in tension between the diaphragm and the attachment plate. An ultrasonic signal may be sensed from the wire (block324), and the ultrasonic signal may be analyzed (block326). One or more characteristics of the sensed ultrasonic signal may be determined (block328), and based at least in part on the determined characteristics of the sensed ultrasonic signal, the measurement of the force may be determined (block330).

In some embodiments consistent with the invention, the ultrasonic signal sensed in block324may be based at least in part on the ultrasonic signal transmitted in block322, where one or more characteristics of the sensed ultrasonic signal may vary as compared to the transmitted ultrasonic signal due to the force the sensor is configured to measure.

FIG. 15is a flowchart340illustrating a sequence of operations consistent with embodiments of the invention. To measure a force using a sensor, consistent with embodiments of the invention, an ultrasonic signal may be generated (block342), and the ultrasonic signal may be transmitted through a wire of the sensor (block344). An ultrasonic signal may be sensed from the wire (block346), and the ultrasonic transmission signal may be analyzed (block348). Based at least in part on the analysis of the sensed ultrasonic signal, the tension of the wire may be determined (block350). Based at least in part on the determined tension, the force may be determined (block352). Furthermore, a temperature associated with the sensor may be determined (block354).

FIG. 16is a flowchart360illustrating a sequence of operations consistent with embodiments of the invention. To measure a force using a sensor, consistent with embodiments of the invention, an ultrasonic signal may be transmitted through a wire of the sensor (block362), and an ultrasonic signal may be sensed from the wire (block364). The sensed ultrasonic signal may be analyzed (block366) to determine one or more characteristics of the sensed ultrasonic signal (block368). Based at least in part on the determined characteristics of the sensed ultrasonic signal, the tension of the wire may be determined (block370). Based at least in part on the determined tension, the force may be measured (block372). The resistance of the wire may be sensed (block374), and based at least in part on the sensed resistance of the wire, a temperature associated with the sensor may be determined (block376).

In some embodiments, the ultrasonic signal sensed from the wire of the sensor may be compared to a reference ultrasonic signal, and the analysis of the sensed ultrasonic signal (block366) may include comparing the sensed ultrasonic signal to the reference ultrasonic signal. In some embodiments, the reference ultrasonic signal may include the transmitted ultrasonic signal, an ultrasonic signal sensed from the wire while the sensor was positioned in an ambient environment, an ultrasonic signal sensed from the wire at a defined pressure, an ultrasonic signal sensed from the wire at a defined deflection of the measuring surface, and/or an ultrasonic signal sensed from the wire at a defined tension. In addition, in some embodiments, changes in one or more ultrasonic signal transmission characteristics of the wire may be determined by comparing the sensed ultrasonic signal to the reference ultrasonic signal. The varying ultrasonic signal transmission characteristics may include phase change, amplitude change, frequency change, frequency band change, and/or propagation time. In turn, one or more measurements associated with the wire may be determined based at least in part on the determined variance of the ultrasonic signal transmission characteristics. The measurements associated with the wire that may be determined based at least in part on the determined variance of the ultrasonic signal transmission characteristics includes the transmission path length of the wire, the tension of the wire, the strain on the wire, and/or the resistance of the wire.

Referring now toFIG. 17,FIG. 17is a flowchart380illustrating steps consistent with some embodiments of the invention. InFIG. 14, a force may be measured with a sensor, where the sensor includes a housing having a first and second end, a diaphragm coupled to the housing proximate the first end, an attachment plate coupled to the housing proximate the second end, and the housing, diaphragm and attachment plate define an interior. The sensor further includes a first wire coupled in tension between the attachment plate and the diaphragm and a second wire coupled to the attachment plate and configured in the interior. An ultrasonic signal may be transmitted through the first wire (block382), and an ultrasonic signal may be sensed from the first wire (block384). The sensed ultrasonic signal may be analyzed (block386) to determine the propagation time of the sensed ultrasonic signal from the first wire (block388). Based at least in part on the determined propagation time of the sensed ultrasonic signal from the first wire, the tension of the first wire may be determined (block390). Based at least in part on the propagation time of the sensed ultrasonic signal from the first wire and/or the determined tension of the first wire, the force may be measured (block392).

In some embodiments, an ultrasonic signal may be transmitted through the second wire (block394), and an ultrasonic signal may be sensed from the second wire (block396). The sensed ultrasonic signal from the second wire may be analyzed (block398) to determine the propagation time of the sensed ultrasonic signal from the second wire (block400). Based at least in part on the determined propagation time of the sensed ultrasonic signal from the second wire, a temperature associated with the sensor may be determined (block402). In some embodiments, the resistance of the second wire may be sensed (block404), and based at least in part on the sensed resistance, a temperature associated with the sensor may be determined (block406).

In some embodiments, an ultrasonic signal may be transmitted through the first wire and an ultrasonic signal may be transmitted through the second wire substantially in parallel (i.e. block382and block394may occur substantially in parallel). Moreover, in some embodiments, the ultrasonic signal transmitted through the first wire and the ultrasonic signal transmitted through the second wire may be a common ultrasonic signal transmitted from an ultrasonic signal transmitter operatively connected to both the first and second wires.

In some embodiments consistent with the invention, a pressure (i.e. a force over an area) may be determined based at least in part on the analysis of an ultrasonic signal transmitted through the tensioned wire. However, in some environments in which a sensor may be deployed, the pressure of the environment may not be the only environmental condition that may cause the ultrasonic signal transmission characteristics of the tensioned wire to vary. For example, a temperature associated with the sensor may cause thermal expansion of the tensioned wire, which may cause one or more ultrasonic signal transmission characteristics to vary. In some embodiments, sensors and sensing methods of the invention determine temperatures associated with the sensor such that the variance of the ultrasonic signal transmission characteristics due to the temperature may be determined, and a temperature compensated pressure measurement may be determined based at least in part on the determined temperature associated with the sensor and the sensed ultrasonic signal from the tensioned wire.

Referring toFIG. 18, which provides a flowchart420,FIG. 18illustrates a sequence of operations consistent with embodiments of the invention for measuring a force using a sensor consistent with embodiments of the invention. An ultrasonic signal sensed from the first wire is analyzed (block422), and an ultrasonic signal sensed from the second wire is analyzed (block424). The phase difference between the sensed ultrasonic signals may be determined using signal processing methods (block426). As the first wire is in tension, the path length of the first wire may vary in response to the force due to pressure on the diaphragm and thermal expansion due to a temperature associated with the sensor. The path length of the second wire, not being in tension, may vary in response to thermal expansion due to a temperature associated with the sensor. As, such, the change in path length of first wire may be offset by the change in path length of the second wire, such that the change in path length of wire one due to thermal expansion may be separated from the change in path length of wire one due to a force on the diaphragm (block428). As such, in some embodiments, a temperature compensated force measurement may be determined (block430).

FIG. 19is an exemplary diagram440illustrating the transmission path lengths of the sensor ofFIG. 3.FIG. 19illustrates the transmission path length of the first wire442at ambient environmental conditions, the transmission path length of the first wire for the relevant force measurement444, and the transmission path length of the second wire for the relevant force measurement446. As shown, the transmission path length of the first wire at ambient environmental conditions442may be longer than both the transmission path length of the transmission path length of the first wire for the relevant force measurement444and the transmission path length of the second wire for the relevant force measurement446. As discussed above, as a force acts on the diaphragm, the transmission path length of the first wire may shorten, as shown at reference444. Moreover, as discussed above, the transmission path length of the second wire may be used to determine a temperature associated with the sensor, such that the thermal expansion of the first wire, thereby increasing the transmission path length may be offset from the determined force measurement. As discussed above, and as shown inFIG. 16, the transmission path lengths of the first wire at ambient conditions442, the first wire for the relevant force measurement444, and the second wire for the relevant force measurement446may be determined by analyzing an ultrasonic signal, such as exemplary ultrasonic signal448. Reference lines450illustrate the transmission path length differences, and analysis of the sensed ultrasonic signals, such as exemplary ultrasonic signal448using known signal processing methods may determine the phase difference of the sensed ultrasonic signals, which in turn may be used to determine the transmission path length differences.

FIG. 20provides an exemplary chart470illustrating experimental data from embodiments of the invention. Chart470provides a pressure measurement474as a function of phase472, where phase472may be the phase difference between sensed ultrasonic signals of the sensors and sensing methods described above. Data line476provides collected data, and data line478provides a theoretical data line.

While the present invention has been illustrated by a description of the various embodiments and examples, and while these embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, while the attachment plates, housings, and diaphragms of some embodiments consistent with the invention have been described as individually defined components, embodiments comprising a housing, attachment plate, and/or diaphragm integrally formed as substantially uniform are contemplated. As such, in some embodiments, a sensor may comprise a housing including a diaphragm, and/or an attachment plate formed thereon.

Moreover, while attachment plates consistent with some embodiments of the invention may be configured as shown for example inFIGS. 1-3, other configurations are contemplated. As such, attachment plates consistent with some embodiments of the invention are configured to secure one or more wires in tension, and may be configured in any suitable manner for providing attachment points for such wires. Thus, an attachment plate consistent with the invention need not be a separate planar member as shown inFIGS. 1-3, but instead may have other geometries, and may be disposed integrally on a housing or other component in a sensor. Practically any component that provides a point of attachment for a wire may be used as an attachment plate in embodiments consistent with the invention.

Moreover, sensors and sensing methods consistent with the invention may be used in sensing environments that conventional sensors and sensing methods generally provide inaccurate results and/or fail completely. Embodiments consistent with the invention may be utilized in a variety of applications where the sensing locations typically are too harsh for conventional sensors and/or sensing methods. Harsh sensing environments typically include one or more extreme environmental conditions that cause inaccurate readings and/or failure of conventions sensors, extreme environmental conditions generally problematic for conventional sensors include, for example, high temperature, high pressure, high strain, high vibrations, wide variations in temperature during operation (i.e. broad temperature range), wide variations in pressure during operation (i.e. broad pressure range), etc. As such, sensors and sensing methods consistent with the invention may be utilized in such harsh sensing environments including, for example, high temperature, pressure, vibration, and/or strain locations in engines (e.g. combustion chambers of aero gas turbine engines), high temperature, pressure, vibration, and/or strain locations in industrial machinery, etc.

As sensors and sensing methods consistent with the invention may transmit ultrasonic signals through wires of substantial length, controllers and or other devices used to analyze the ultrasonic signals to determine a measurement of one or more environmental conditions of a harsh sensing location may be remote from the harsh sensing location thereby increasing the reliability of components that may be particularly sensitive to the environmental conditions of the harsh sensing location. Therefore, sensors and sensing methods consistent with the invention may be utilized in a wide variety of applications to provide improved sensors and sensing methods as compared to conventional sensors and sensing methods. In addition, sensors and sensing methods consistent with the invention may be utilized in a wide variety of applications where conventional sensing technology is unreliable, inaccurate and/or inoperable. Thus, the invention in its broader aspects is therefore not limited to the specific details and representative apparatuses shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants' general inventive concept.