Patent Description:
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustor section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.

Detailed knowledge of gas turbine engine and other machinery operation for control or health monitoring requires sensing systems that need information from locations that are sometimes difficult to access due to moving parts, internal operating environment or machine configuration. The access limitations make wire routing bulky, expensive and vulnerable to interconnect failures. The sensor and interconnect operating environments for desired sensor locations often exceed the capability of the interconnect systems. In some cases, cable cost, volume and weight exceed the allowable limits for practical applications.

Application of electromagnetic sensor technologies to address the wiring constraints faces the challenge of providing reliable communications in a potentially unknown environment with potential interference from internal or external sources.

<CIT> discloses a control and health monitoring system comprising a control sensing device within a shielded sub-system component and a remote processing unit.

<CIT> discloses transmission of data from a radio tag to a centralised maintenance system.

Viewed from one aspect the present invention provides a system according to claim <NUM>.

The electrical interface device may be disposed within the sub-system component.

The electrical interface device may be mounted to at least one of an external surface and integrally with the sub-system component.

The device may be configured to communicate over an electromagnetic local area network.

The electromagnetic local area network may operate with a frequency from a K band to a W band.

The shielding may be configured to contain electromagnetic communication signals within the sub-system component.

The remote processing unit may be provided with a first security key and the device may be provided with a second security key.

In response to an exchange of the first security key and the second security key, the device may be configured to provide the electrical interface device data to the remote processing unit.

At least one of the first security key and the second security key may be provided with a unique tag.

The waveguide may include a waveguide transmitter interface that enables electromagnetic signal transmission within a guidance structure to a waveguide transition interface incorporating a transition window.

The subject matter which is regarded as the present disclosure is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

Various embodiments of the present disclosure are related to electromagnetic communication in a machine. <FIG> schematically illustrates a gas turbine engine <NUM> as one example of a machine as further described herein. The gas turbine engine <NUM> is depicted as a two-spool turbofan that generally incorporates a fan section <NUM>, a compressor section <NUM>, a combustor section <NUM> and a turbine section <NUM>. Alternative engines may include an augmentor section (not shown) among other systems or features. The fan section <NUM> drives air along a bypass flow path B in a bypass duct to provide a majority of the thrust, while the compressor section <NUM> drives air along a core flow path C for compression and communication into the combustor section <NUM> then expansion through the turbine section <NUM>. Although depicted as a two-spool turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with two-spool turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures or any other machine that requires sensors to operate with similar environmental challenges or constraints. Additionally, the concepts described herein may be applied to any machine or system comprised of control and / or health monitoring systems.

It should be understood that various bearing systems at various locations may alternatively or additionally be provided and the location of bearing systems <NUM> may be varied as appropriate to the application.

A combustor <NUM> is arranged in exemplary gas turbine engine <NUM> between the high pressure compressor <NUM> and the high pressure turbine <NUM>.

The geared architecture <NUM> may be an epicycle gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about <NUM>:<NUM>.

The fan section <NUM> of the engine <NUM> is designed for a particular flight condition -- typically cruise at about <NUM> Mach and about <NUM>,<NUM> feet (about <NUM>,<NUM> metres). The flight condition of <NUM> Mach and <NUM>,<NUM> ft (<NUM>,<NUM>), with the engine at its best fuel consumption - also known as "bucket cruise Thrust Specific Fuel Consumption ('TSFC')" - is the industry standard parameter of Ibm of fuel being burned divided by Ibf of thrust the engine produces at that minimum point. The "Low corrected fan tip speed" as disclosed herein according to one non-limiting embodiment is less than about <NUM> ft/second (<NUM>/s).

The exemplary gas turbine engine includes the fan <NUM> that comprises in one non-limiting embodiment less than about twenty-six (<NUM>) fan blades. In another non-limiting embodiment, the fan section <NUM> includes less than about twenty (<NUM>) fan blades. Moreover, in one disclosed embodiment the low pressure turbine <NUM> includes no more than about six (<NUM>) turbine rotors schematically indicated at <NUM>. In another non-limiting example embodiment the low pressure turbine <NUM> includes about three (<NUM>) turbine rotors. A ratio between the number of fan blades and the number of low pressure turbine rotors is between about <NUM> and about <NUM>. The example low pressure turbine <NUM> provides the driving power to rotate the fan section <NUM> and therefore the relationship between the number of turbine rotors <NUM> in the low pressure turbine <NUM> and the number of fan blades in the fan section <NUM> disclose an exemplary gas turbine engine <NUM> with increased power transfer efficiency.

The disclosed gas turbine engine <NUM> includes a control and health monitoring system <NUM> (generally referred to as system <NUM>) utilized to monitor component performance and function. In this example, a sensing / control / identification device (SCID) 68A is located within a sub-system component (SSC) <NUM>. The SCID 68A communicates with electromagnetic energy to a remote processing unit (RPU) <NUM> through a path comprised of a transmission path <NUM> and a path <NUM> within a SSC <NUM> as best seen in <FIG>. The path may also be extended along one or more shielded paths <NUM> to SCIDs 68B in separate SSCs <NUM> (<FIG>). This entire path (e.g., transmission path <NUM>, path <NUM>, and shielded paths <NUM>) comprises a shielded electromagnetic network (SEN) <NUM>. The SCIDs 68A, 68B, 68C are provided with an embedded wireless (electromagnetic) communication device to enable the SCIDS 68A, 68B, 68C to communicate with the RPU <NUM>. The RPU <NUM> may transmit signals to a network <NUM> of the SCID 68A, 68B, 68C (<FIG>) and/or receive information indicative of current operation of the component being monitored. The transmission media for any portion of the SEN <NUM> may include solid, liquid or gaseous material. In this example, a pressure internal to the SSC <NUM> is monitored and that information transmitted through the path <NUM> of the SEN <NUM> to the RPU <NUM> for use in controlling engine operation or monitoring component health. However, it should be understood that it is within the contemplation of this disclosure that the disclosed system <NUM> may be utilized to control and/or monitor any component function or characteristic of a turbomachine or aircraft component operation and/or other machines.

Prior control & diagnostic system architectures utilized in various applications include centralized system architecture in which the processing functions reside in an electronic control module. Redundancy to accommodate failures and continue system operation systems are provided with dual channels with functionality replicated in both control channels. Actuator and sensor communication is accomplished through analogue wiring for power, command, position feedback, sensor excitation and sensor signals. Cables and connections include shielding to minimize effects caused by electromagnetic interference (EMI). The use of analogue wiring and the required connections limits application and capability of such systems due to the ability to locate wires, connectors and electronics in small and harsh environments that experience extremes in temperature, pressure, and/or vibration.

Referring to <FIG>, the system <NUM> includes SEN <NUM> installed near, in, or on each of several SSCs 70A-C, as examples of the SSC <NUM> of <FIG>. Each of the SSCs 70A-C may be an engine component, actuator or any other machine part from which information and communication is performed for monitoring and/or control purposes. In this example, each of the SSCs 70A-C includes a path <NUM> of the SEN <NUM> that is the primary means of communicating with one or multiple features of the particular SSC 70A-C or remotely located SSCs <NUM>. The remotely located SSCs <NUM> may contain a single or multiple electronic circuits or sensors configured to communicate over the SEN <NUM>.

The RPU <NUM> sends and receives power and data to and from the SSCs 70A-C and may also provide a communication link between different SSCs 70A-C. The RPU <NUM> may be located on equipment near other system components or located remotely as desired to meet application requirements.

A transmission path (TP) <NUM> between the RPU <NUM> and SSCs 70A-C is used to send and receive data routed through the RPU <NUM> from a control module or other components. The transmission path (TP) <NUM> is configured as a protected communication channel as part of the SEN <NUM> between the RPU <NUM> and the SSCs 70A-C. The TP <NUM> according to the invention includes a waveguide and may further utilize electrical wire, optic fibre or any other electromagnetic communication including radio frequency / microwave electromagnetic energy, visible or non-visible light. The interface between the TP <NUM> and SSC 70A-C transmits power and signals received through the TP <NUM> to one or multiple SCIDs 68A in the example SSC 70A.

The exemplary SCIDs 68A, 68B, 68C may be radio-frequency identification (RFID) devices that include processing, memory and/or the ability to connect to conventional sensors or effectors such as solenoids or electro-hydraulic servo valves. The SSC 70A may contain radio frequency (R/F) antennas, magnetic devices or optic paths designed to be powered and/or communicate to from the TP <NUM> paths. The SSCs 70A-C may also use shielded paths <NUM> that can be configured as any type of electromagnetic communication, including, for instance, a radio frequency, microwaves, magnetic or optic waveguide transmission to the SCIDs 68B located within the remotely located SSCs <NUM>.

Shielding <NUM> within and around the SSC 70A is provided such that electromagnetic energy or light interference <NUM> with electromagnetic communication signals (wireless communication signals) <NUM> (shown schematically as arrows) within the SSC 70A are mitigated. Moreover, the shielding <NUM> provides that the signals <NUM> are less likely to propagate into the environment outside the SSC 70A and enable unauthorized access to information. Similarly, remotely located SSCs <NUM> can each include respective shielding <NUM> to limit signal propagation to shielded paths <NUM>. In some embodiments, confined electromagnetic radiation is in the range <NUM> - <NUM>. Electromagnetic radiation can be more tightly confined around specific carrier frequencies, such as <NUM> - <NUM>, <NUM>, <NUM>, or <NUM> - <NUM> as examples in the microwave spectrum. A carrier frequency can transmit electric power, as well as communicate information, to multiple SCIDs 68A, 68B, 68C using various modulation and signalling techniques.

RFID, electromagnetic or optical devices implemented as the SCIDs 68A, 68B, 68C may provide information indicative of a physical internal parameter, such as a pressure source, a pressure, a temperature, a speed, proximity, vibration, identification and/or other internal parameters used for monitoring or controlling component operation. The SCIDs 68A, 68B, 68C may also include control devices such as a solenoid, switch or other physical actuation devices. Signals communicated over the TP <NUM> may employ techniques such as checksums, hash algorithms, shielding and/or encryption to mitigate cyber security threats and interference.

The RFID, electromagnetic or optical devices implemented as the SCIDs 68A, 68B, 68C may be physically collocated with an being operatively connected to the at least one electrical interface device (EID) <NUM> while both are operatively connected to at least one of the SSCs 70A-C. Alternately, SCIDs 68C may be operatively connected to at least one of the ElDs <NUM> such that removal of the EID90 would also remove the connected SCID 68C. The at least one EID <NUM> may be disposed within at least one of the SSCs 70A-C and within the shielding <NUM>. The at least one EID <NUM> may be mounted to an external surface of or integrally with at least one of the SSCs 70A-C for easier service or removal during field operation.

The SCIDs 68A, 68B, 68C are configured to characterize single or multiple devices in the system <NUM>. More specifically, the SCIDs 68A, 68B, 68C are configured to characterize the EID <NUM> based on the EID <NUM> being provided with electrical interface device data. The SCIDs 68A, 68B, 68C may be provided with an on-board memory that is configured to locally retain or store usage data, calibration data (e.g. sensor calibration data, solenoid impedance values over temperature, use characteristics of an electro-hydraulic servo valve, etc.), EID identifying information (e.g. device serial number, device type, etc.), and EID characteristics (e.g. in-service time, total number of cycles, usage information etc.) to characterize the EID <NUM> or multiple EIDs. The SCIDs <NUM> are configured to store and associate the calibration data and/or EID characteristics with the EID identifying information.

The on-board memory is operable for storing and retrieving data, including software and/or firmware instructions. Any suitable type of memory storage device may be included, such as random-access memory (RAM) and read-only memory (ROM) Computer-readable storage devices or media may be implemented using any of a number of known memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable instructions used by the SCIDs 68A, 68B, 68C, the RPU <NUM>, and/or the system <NUM> in keeping, using, or calibrating the EID <NUM> based on the calibration data of the EID <NUM>, use characteristics of the EID <NUM>, EID identifying information, and EID characteristics.

The individual EID <NUM> that is installed into at least one of the SSCs 70A-C is assigned a unique identifier, such as the EID serial number or other EID identifying information at the time of manufacture. The unique identifier is read by the system <NUM>, the RPU <NUM>, or the SCIDs 68A, 68B, 68C. The SCIDs 68A, 68B, 68C may be populated with the calibration data, usage data, EID identifying information, and/or the EID characteristics at time of manufacture and/or during operation and is associated with the unique identifier. Updates of the calibration data and/or the EID characteristics may occur in real time during operation of the system <NUM> or during repair/overhaul of at least one of the SSCs 70A-C and a remain associated with the unique identifier. Should a replacement EID be installed into at least one of the SSCs 70A-C to replace the individual EID <NUM>, the replacement EID and it's identifier that is different from the unique identifier of the removed device. The another identifier is stored by the system <NUM>, the RPU <NUM>, or the SCIDs 68A, 68B, 68C. The SCIDs 68A, 68B, 68C may be populated with the replacement EID calibration data, replacement EID usage data, replacement EID identifying information, and/or the replacement EID characteristics and is associated with the another identifier. The calibration data, usage data, identifying information, and/or characteristics that are associated with each identifier are stored separately by the system <NUM>, the RPU <NUM>, or the SCID 68A, 68B, 68C. The calibration data, usage data, identifying information, and/or characteristics associated with the unique identifier are updated during operation of the system <NUM> or during repair/overhaul of at least one of the SSCs 70A-C when the EID <NUM> is installed. The calibration data, usage data, identifying information, and/or characteristics associated with the another identifier are updated during operation of the system <NUM> or during repair/overhaul of at least one of the SSCs 70A-C when the replacement EID is installed.

The EID <NUM> is in communication with the system <NUM> through an EID interface <NUM> that is operatively connected to the RPU <NUM>. The EID interface <NUM> may use electrical, optical, or alternate forms of energy to communicate with the externally mounted (outside of the SSC <NUM>) RPU <NUM>.

The calibration data, usage data, and/or EID characteristics that are associated with the EID identifying information that are stored in the SCIDs 68A, 68B, 68C may be communicated to the RPU <NUM> via the transmission path <NUM>. The characteristics of the EID <NUM> stored in the SCIDs 68A, 68B, 68C may be used by the system <NUM> to identify the ElDs <NUM> by serial number and reduce uncertainty of EID <NUM> operation. The storing of the characteristics of the EID <NUM> may enable the use of the sensor calibration data to reduce sensor error, the stored solenoid impedance values over temperature or use characteristics of an electro-hydraulic servo valve may reduce null bias current shift effects.

The storing and usage of the characteristics of the EID <NUM> by the SCIDs <NUM> may enable the EID <NUM> to be calibrated to provide precise operation of a wide variety of operating ranges and conditions. The storing of the EID characteristics by the SCIDs <NUM>, 68B and associating the EID characteristics with the EID <NUM> enable the tracking of the EID characteristics by the system <NUM> without relying on a disconnected database or database that is external to the system <NUM>.

The disclosed system <NUM> containing the SEN <NUM> (e.g., transmission path <NUM>, path <NUM>, and shielded paths <NUM>) provides a communication link between the RPU <NUM> and multiple SSCs 70A-C, <NUM>. The shielding <NUM>, <NUM> may be provided along the transmission path <NUM> and for each SSC 70A-C and separate SSC <NUM> such that power and communication signals are shielded from outside interference, which may be caused by environmental electromagnetic or optic interference. Moreover, the shielding <NUM>, <NUM> prevents intentional interference <NUM> with communication at each component. Intentional interference <NUM> may take the form of unauthorized data capture, data insertion, general disruption and/or any other action that degrades system communication. Environmental sources of interference <NUM> may originate from noise generated from proximate electrical systems in other components or machinery along with electrostatic fields, and/or any broadcast signals from transmitters or receivers. Additionally, pure environmental phenomena, such as cosmic radio frequency radiation, lightning or other atmospheric effects, could interfere with local electromagnetic communications. Accordingly, the individualized shielding <NUM>, <NUM> for each of the SSCs 70A-C and separate SSCs <NUM> prevent the undesired interference with communication. The shielding <NUM>, <NUM> may be applied to enclosed or semi-enclosed volumes that contain the SCIDs 68A, 68B, 68C.

It should be appreciated that while the system <NUM> is explained by way of example with regard to a gas turbine engine <NUM>, other machines and machine designs can be modified to incorporate built-in shielding for each monitored or controlled components to enable the use of a SEN. For example, the system <NUM> can be incorporated in a variety of harsh environment machines, such as an elevator system, heating, ventilation, and air conditioning (HVAC) systems, manufacturing and processing equipment, a vehicle system, an environmental control system, and the like. The disclosed system <NUM> includes the SEN <NUM> that enables consistent communication with electromagnetic devices, such as the exemplary SCIDs 68A, 68B, 68C, and removes variables encountered with electromagnetic communications such as distance between transmitters and receiving devices, physical geometry in the field of transmission, control over transmission media such as air or fluids, control over air or fluid contamination through the use of filtering or isolation and knowledge of temperature and pressure.

The system <NUM> provides for localized transmission to SCIDs 68A, 68B, 68C such that power requirements are reduced. Localized transmission occurs within a shielded volume of each SSC 70A-C, <NUM> that is designed specifically to accommodate reliable electromagnetic transmission for the application specific environment and configuration. Shielding of localized components is provided such that electromagnetic signals are contained within the shielding <NUM> for a specific instance of the SSC 70A-C. The system <NUM> therefore enables communication with one or multiple SCIDs 68A, 68B, 68C simultaneously. The exemplary RPU <NUM> enables sending and receiving of data between several different SSCs 70A-C and separate SSCs <NUM>. The RPU <NUM> may be located on the equipment near other system components or located away from the machinery for any number of reasons.

The system <NUM> provides for a reduction in cable and interconnecting systems to reduce cost and increases reliability by reducing the number of physical interconnections. Reductions in cable and connecting systems further provides for a reduction in weight while enabling additional redundancy without significantly increasing cost. Moreover, additional sensors can be added without the need for additional wiring and connections that provide for increased system accuracy and response. Finally, the embodiments enable a "plug-n-play" approach to add a new SCID, potentially without a requalification of the entire system but only the new component; thereby greatly reducing qualification costs and time.

The TP <NUM> between the RPU <NUM> and the SSCs 70A-C utilized to send and receive data from other components may take multiple forms such as electrical wire, optic fibre, radio frequency signals or energy within the visible or non-visible light spectrum. The numerous options for a communication path of the TP <NUM> enable additional design flexibility. The TP <NUM> transfers energy to the SSC 70A-C such that one or multiple SCIDs 68A, 68B, 68C can be multiplexed over one TP <NUM> to the RPU <NUM>.

SCIDs 68A, 68B, 68C may include RFID functionality with processing, memory and/or the ability to connect to conventional sensors. Radio frequency (R/F) antennas, magnetic devices or optic paths within the SSCs 70A-C may be designed to communicate with one or multiple SCIDs 68A, 68B, 68C. Moreover, R/F, magnetic or optic waveguide transmission paths i.e. <NUM>, <NUM> may be utilized to communicate with individual devices, such as the SCIDs 68A, 68B, 68C or that are locally or remotely located from the SSC 70A-C, <NUM>.

Shielding <NUM>, <NUM> within and around the SSC 70A-C, <NUM> substantially prevents electromagnetic energy or light interference with signals and also makes it less likely that signals can propagate into the surrounding environment to prevent unauthorized access to information.

According to embodiments, electromagnetic (EM) communication with the system <NUM> can be performed through multi-material and functional components including, for instance, fuel, oil, engineered dielectrics and enclosed free spaces. By forming waveguides through existing machine components and using electromagnetic communication for one or more of the TP <NUM>, path <NUM>, and/or shielded paths <NUM>, system contaminants and waveguide size for given frequencies can be reduced.

In embodiments, existing components of the gas turbine engine <NUM> of <FIG> can be used to act as waveguides filled with air, fluids or a specifically implemented dielectric to transmit EM energy for writing and reading to/from EM devices in a Faraday cage protected environment. Use of existing structure can allow waveguide channels to be built in at the time of manufacture by machining passages or additively manufacturing waveguide channels as communication paths. For example, communication paths can be built into the structure of SSCs 70A-C and <NUM> to guide EM energy through each component. The SSCs 70A-C and <NUM> may contain gas such as air at atmospheric pressure or any other level, or liquids such as oil or fuel. In any part of the system <NUM>, a dielectric may be employed to resist contamination or to reduce requirements for waveguide dimensions.

Various machine components are also used for transmission if the proper waveguide geometry is designed into the component, which can also provide functional and structural aspects of the machine. Examples, such as machine housings, fluid (including air) fill tubes, hydraulic lines, support frames and members, internal machine parts and moving parts that can be coupled or shaped into waveguide geometry may also be incorporated in embodiments. As one example, <FIG>. and <FIG> depict a plurality of compressor vane segments <NUM> of the compressor section <NUM> of <FIG> that incorporate one or more communication paths <NUM> integrally formed in/on a component of the gas turbine engine <NUM> of <FIG>. Each communication path <NUM> routes a portion of electromagnetic signals communicated from the TP <NUM> to one or more of the SCIDs <NUM> of <FIG>. Each communication path <NUM> also provides a potentially alternate route in which the electromagnetic signal can be channelled in the event of a line or linkage failure, thereby building in inherent redundancy and system level robustness.

In the example of <FIG>, the compressor vane segment <NUM> includes an arcuate outer vane platform segment <NUM> and an arcuate inner vane platform segment <NUM> radially spaced apart from each other. The arcuate outer vane platform segment <NUM> may form an outer portion and the arcuate inner vane platform segment <NUM> may form an inner portion to at least partially define an annular compressor vane flow path.

Communication path <NUM> in a vane <NUM> can be formed during a manufacturing process to directly carry electromagnetic signalling of the TP <NUM> through a component of the gas turbine engine <NUM> of <FIG> directly to a SCID <NUM> depicted in <FIG>. Communication path <NUM> can also terminate with SCIDs <NUM> to read pressures, temperatures or other parameters at the end of the TP78 or <NUM>. Waveguide usage can enable very low transmission losses such that the RPU <NUM> of <FIG> can be physically located much further away from the SCIDs 68A, 68B, 68C of <FIG> than conventional free space transmitting devices. Use of a dielectric in the waveguides can reduce the dimensional requirements for the waveguides and resist contaminants, such as moisture, particles, gases, corrosion and/or liquids that may increase transmission losses. Embodiments can use fluids in existing systems to act as a dielectric, particularly fluids with a dielectric constant that approaches or is better than free space. Thus, existing fuel or oil lines of the gas turbine engine <NUM> of <FIG> may be used as waveguides if they have appropriate dielectric properties.

Further embodiments include allowing transition of EM energy from a waveguide into a free space environment. Some of the SSCs 70A-C, <NUM> of <FIG> have multiple SCIDs 68A, 68B, 68C that reside in a protected Faraday cage (e.g., a shielded volume within shielding <NUM>, <NUM>) filled with air or other fluids. Transitioning energy from a waveguide to and from an open cavity is required to prevent unwanted signal loss. Embodiments transition EM energy from TP <NUM> into a free space environment containing either air or a fluid within shielding <NUM> of SSC 70A of <FIG> using an example waveguide <NUM> of <FIG>. The waveguide <NUM> is part of an embodiment of the TP <NUM> and optionally of the shielded path <NUM> of <FIG>. In some embodiments, EM energy transitions through multiple interfaces having different environmental characteristics, such as waveguide <NUM> of <FIG> as a further example of the shielded path <NUM> of <FIG>. Waveguides <NUM>, <NUM> can connect multiple SCIDs <NUM> and may pass through existing components, for instance, in communication path <NUM> of <FIG>, to facilitate transmission of EM power and signalling between devices. The waveguides <NUM>, <NUM> may incorporate "T"s, "Y"s, splitters or other branching types to facilitate a network topology.

EM energy may be confined to a waveguide, or alternatively can be transmitted through a combination of waveguide and free space communications in a shielded environment, e.g., within shielding <NUM>, <NUM> of <FIG>, to meet system requirements for signal attenuation and disturbances. Waveguide <NUM> of <FIG> can include a waveguide transmitter interface <NUM> that enables electromagnetic signal transmission within a waveguide medium or electromagnetic window <NUM> in a guidance structure <NUM> to a waveguide transition interface <NUM>. The waveguide transmitter interface <NUM> may be an EM energy emitter, and the waveguide transition interface <NUM> may be operable to pass the EM energy through shaping, an antenna structure, or an active structure to a confined free space within shielding <NUM>, <NUM> of <FIG>. The waveguide medium <NUM> can be a gas or liquid, such as air, oil, fuel, solid dielectric, or the like. In some embodiments, the waveguide medium <NUM> is a dielectric. The guidance structure <NUM> can be a metal tube and may be integrally formed on/within a component of the gas turbine engine <NUM> of <FIG>, such as communication path <NUM> of <FIG>. In other embodiments, the guidance structure <NUM> is an outer edge of a dielectric and need not include a metallic structure. Although depicted as a single straight path, it will be understood that the waveguide <NUM> can bend and branch to reach multiple SCIDs 68A, 68B, 68C of <FIG>. In other embodiments, the waveguide <NUM> may take the form of a planar stripline, or trace on a printed circuit board.

Transitioning EM energy from a waveguide to and from cavities using TP <NUM> and/or shielded paths <NUM> can present a challenge when SCIDs 68A, 68B, 68C of <FIG> are located in higher temperature or pressure environments, especially in environments containing fuel, oil, flammable liquids or the associate vapours. With further reference to <FIG>, the waveguide <NUM> enables transitioning of EM energy from a first environment <NUM> into a second environment <NUM> with a higher temperature and/or higher pressure capable barrier against fluids or gasses. Waveguide <NUM> of <FIG> can include a waveguide transmitter interface <NUM> that enables electromagnetic signal transmission within a guidance structure <NUM> to a waveguide transition interface <NUM>. The waveguide transmitter interface <NUM> may be an EM energy emitter in the first environment <NUM>. The waveguide transition interface <NUM> may be operable to pass the EM energy through shaping, an antenna structure, or an active structure from a first portion <NUM> of the waveguide <NUM> to a second portion <NUM> of the waveguide <NUM>. The first portion <NUM> of the waveguide <NUM> may have a first waveguide medium <NUM> that is different from a second waveguide medium <NUM> of the second portion <NUM>. A transition window <NUM> can be incorporated in the waveguide transition interface <NUM> as a dielectric or thin metal EM window operable to pass a frequency range of interest between the first portion <NUM> and the second portion <NUM> of the waveguide <NUM>. The second portion <NUM> of the waveguide <NUM> can also include a secondary waveguide transition interface <NUM> in the second environment <NUM>. The secondary waveguide transition interface <NUM> can act as a seal to prevent higher temperatures and/or pressures of the second environment <NUM> from directly contacting the first portion <NUM> of the waveguide <NUM>. The first waveguide medium <NUM> and the second waveguide medium <NUM> can be different gasses or liquids, such as air, oil, fuel, or the like and may have different nominal pressures and/or temperatures. In some embodiments, the first waveguide medium <NUM> and/or the second waveguide medium <NUM> is a dielectric. The guidance structure <NUM> can be a metal tube and may be integrally formed on/within a component of the gas turbine engine <NUM> of <FIG>, such as communication path <NUM> of <FIG>. The guidance structure may also contain more than one waveguide transition interface <NUM> with a corresponding transition window <NUM> for redundancy purposes. Although depicted as a single straight path, it will be understood that the waveguide <NUM> can bend, T, and branch to reach multiple SCIDs 68A, 68B, 68C of <FIG>.

The disclosed system <NUM> containing the SEN <NUM> (e.g., transmission path <NUM>, path <NUM>, and shielded paths <NUM>) may be a protected embedded electromagnetic architecture configured as a R/F multiplexed communication closed communication system that provides a protected communication channel between the RPU <NUM> and multiple SSCs 70A-C, <NUM>, and the SCIDs 68A, 68B, 68C.

The RPU <NUM> may be configured to communicate with ElDs <NUM> through the EID interface <NUM>. Alternately, all communication may be implemented through the SCIDs 68A, 68B, 68C. The RPU <NUM> is configured to communicate wirelessly with the SCIDs 68A, 68B, 68C through the transmission path <NUM> and/or the shielded paths <NUM>. An electromagnetic local area network is established that uses various wireless protocols such as radio frequency communication, radar based communication, microwave based communication, etc..

In at least one embodiment, the at least one SCID 68A, 68B, 68C may use architectures or chipsets that are configured to operate at a frequency within the range of <NUM> to <NUM> , the K band (<NUM> to <NUM>), or the W band (<NUM> to <NUM>). The SCIDs 68A, 68B, 68C may be confined to the <NUM> to <NUM> bandwidth. In at least one embodiment, the at least one SCID 68A, 68B, 68C may operate with a frequency from the K band to the W band. By confining the communication of the at least one SCID 68A, 68B, 68Cto the K or W energy band to a microwave channel, wide signal bandwidths may be achieved without concern of multi-system interface. Furthermore, wide signal bandwidths enable multi-node interrogation at high rates.

The protected embedded electromagnetic architecture is an enterprise R/F system that provides various levels of encryption or protocols such that the calibration data, usage data, EID identifying information, and/or the EID characteristics of the associated EID <NUM> may only be read by the SCIDs <NUM> or changed/updated by the SCIDs <NUM> through a key exchange.

<FIG> is an illustrative flowchart of a method of key exchange to enable communication between the RPU <NUM> and the SCIDs 68A, 68B, 68C. A key exchange may occur between the RPU <NUM> and the SCIDs 68A, 68B, 68C prior to the reading, changing, or updating of the calibration data, usage data, EID identifying information, and/or the EID characteristics of the associated ElDs <NUM> by the RPU <NUM>, at least one of the SCIDs <NUM>, and/or the system <NUM>.

At block <NUM>, the RPU <NUM> may be provided with a first security key. At block <NUM>, the at least one of the SCIDs 68A, 68B, 68C may be provided with a second security key. The first security key and the second security key may be a public / private key pair or a private / private key pair.

The first security key and the second security key may be encryption keys in the form of hardwired coding made at the time of RPU <NUM> or SCID 68A, 68B, 68C fabrication, physically imprinted by UV light exposure or written on features of the EID <NUM> or SCID 68A, 68B, 68C by fusing techniques, bit encoding, optical encoding with multi-bit elements, or software protocols. The software protocols may be Diffie-Hellman key exchange protocol, DSS (Digital Signature Standard) that incorporates the Digital Signature Algorithm, ElGamal, various elliptic curve techniques, various password-authenticated key agreement techniques, Paillier cryptosystem, RSA encryption algorithm (PKCS#<NUM>), Cramer-Shoup cryptosystem, YAK authenticated key agreement protocol, or the like.

At block <NUM>, a security key request may be generated by the SCID 68A, 68B, 68C, the RPU <NUM>, and/or the system <NUM>. The security key request may be generated in response to a request from at least one of the SCID 68A, 68B, 68C, the RPU <NUM>, and/or the system <NUM> to use the calibration data of the EID <NUM>, use characteristics of the EID <NUM>, use EID identifying information, or calibrate system based on the calibration data of the EID <NUM>, use characteristics of the EID <NUM>, EID identifying information, and EID characteristics. If a security key request has not been generated, the method may end. Should a security key request be generated, the method continues to block <NUM>.

At block <NUM>, the method verifies whether the first security key of the SCID 68A, 68B, 68C and the second security key is trusted. The first security key may be verified at the RPU <NUM> communication. The second security key may be verified at the SCID 68A, 68B, 68C. At least one of the first security key and the second security key may be verified by identifying a unique tag associated with at least one of the first security key and the second security key. The unique tag identifies at least one of the first security key and the second security as being provided by a trusted source. The unique tag may also include information as to whether the requesting device is a read/write or read only. If the first security key and/or the second security key is not verified, the method may end. Should the first security key and/or the second security key be verified, the method continues to block <NUM>.

At block <NUM>, the method exchanges the first security key and the second security key. At block <NUM>, electrical interface device data is exchanged between the SCID <NUM>, the RPU <NUM>, and/or the system <NUM>. For example, the SCID 68A, 68B, 68C provides or transfers the EID data or the calibration data of the EID <NUM>, use characteristics of the EID <NUM>, EID identifying information, and/or EID characteristics to the RPU <NUM> and/or the system <NUM>. At block <NUM> at least one of the RPU <NUM>, the SCID <NUM>, and/or the system <NUM> is enabled to read and/or store the calibration data of the EID <NUM>, use characteristics of the EID <NUM>, EID identifying information, and/or EID characteristics based on at least one of the first security key, the second security key, and an encrypted link.

Claim 1:
A system comprising:
a gas turbine engine (<NUM>);
a device (68A, 68B, 68C) disposed within a sub-system component (70A, 70B, 70C) of the gas turbine engine, wherein the device is configured to monitor component performance and function and optionally operates as a control and/or identification device;
a shielding (<NUM>) disposed about the sub-system component (70A, 70B, 70C);
a remote processing unit (<NUM>) positioned external to the sub-system component (70A, 70B, 70C), the remote processing unit (<NUM>) configured to be in electromagnetic communication with the device (68A, 68B, 68C);
a transmission path (<NUM>) that extends between the remote processing unit (<NUM>) and the sub-system component (70A, 70B, 70C), the transmission path (<NUM>) being a protected communication channel for the remote processing unit (<NUM>) to communicate with the device (68A, 68B, 68C) through the transmission path (<NUM>), wherein the transmission path (<NUM>) includes a waveguide (<NUM>; <NUM>); and
one or more communication paths (<NUM>) integrally formed in/on a component (<NUM>) of the gas turbine engine (<NUM>), each communication path (<NUM>) being arranged to route a portion of electromagnetic signals communicated from the transmission path (<NUM>) to the device (68A, 68B, 68C), characterised by:
an interface between the transmission path (<NUM>) and the subsystem component (70A, 70B, 70C) adapted to transmit power and signals received through the transmission path (<NUM>) to the device (68A, 68B, 68C), wherein the communication with the device (68A, 68B, 68C) through the transmission path (<NUM>) is via the interface;
an electrical interface device (<NUM>), referred to as EID, operatively connected to the sub-system component (70A, 70B, 70C), the EID (<NUM>) being operatively connected to and in communication with the device (68A, 68B, 68C), the device (68A, 68B, 68C) being configured to retain identification, calibration or other operational data associated with the EID (<NUM>) to characterise the EID (<NUM>); and
an EID interface (<NUM>) that operatively connects the remote processing unit (<NUM>) with the EID (<NUM>).