Abstract:
Embodiments are directed to a method comprising: providing, by a coil embedded in a structure of a rotor hub composed of a paramagnetic material, power to at least one sensor, and receiving, by the coil, data from the at least one sensor. Embodiments are directed to a system comprising: a coil embedded in a structure of a rotor hub composed of a paramagnetic material, and a plurality of sensors communicatively coupled to the coil and configured to receive power from the coil.

Description:
BACKGROUND 
       [0001]    The rotor of a rotating wing aircraft is the main load bearing structure and consequently faces different kinds of stresses during a flight profile. Sensors may be added to a rotor hub for purposes of health monitoring, with a view towards condition-based maintenance (CBM). 
         [0002]    Sensors on the rotor hub need power in order to: (1) sense the data, and (2) communicate sensed data to a processing unit where it is collated and processed into information needed for CBM or diagnostics, prognostics, and health management (DPHM). Providing power is a challenge due to at least two factors: (1) use of batteries as a power source being impractical due to the finite life of the battery and a lack of serviceable access to replace worn batteries, and (2) using of wiring harnesses being unreliable due to stresses and environmental conditions. Similarly, communications with sensors on the hub is challenging for at least two reasons: (1) wiring harnesses (or a lack thereof) for traditional wired communications, and (2) E-field interference from electro-magnetic (EM) sources on the aircraft and intentional jammers for traditional wireless communications. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    Embodiments are directed to a method comprising: providing, by a coil embedded in a structure of a rotor hub composed of a paramagnetic material, power to at least one sensor, and receiving, by the coil, data from the at least one sensor. 
         [0004]    Embodiments are directed to a system comprising: a coil embedded in a structure of a rotor hub composed of a paramagnetic material, and a plurality of sensors communicatively coupled to the coil and configured to receive power from the coil. 
         [0005]    Additional embodiments are described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0007]      FIG. 1  is a diagram of a rotorcraft; 
           [0008]      FIG. 2  is a diagram of system for transferring power and data; 
           [0009]      FIG. 3  is a diagram of a system demonstrating placement of one or more loops for transferring power and data; 
           [0010]      FIG. 4  is a diagram illustrating a transfer of data; and 
           [0011]      FIG. 5  is a flow chart of an exemplary method. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. In this respect, a coupling between entities may refer to either a direct or an indirect connection. 
         [0013]    Exemplary embodiments of apparatuses, systems, and methods are described for enabling wireless power and data transfer capability to sensors embedded in a hub of a rotating wing aircraft. The aircraft may operate in harsh environments for extended periods of time without the need for battery replacement over the lifetime of one or more products. In some embodiments, a rotor head or hub may be fabricated out of one or more materials, such as titanium. The titanium may serve or function as a paramagnetic material, much like an air gap in connection with wireless transmissions. In this respect, communication (e.g., a power transfer) might not be subjected to multipath conditions. 
         [0014]    In some embodiments, variations in bulk manufacturing techniques may be identified in connection with center frequencies of coils. A ‘Q-factor’ may be derived and utilized to optimize a frequency division multiplexing (EDM) technique, thereby maximizing performance or efficiency of data transfer. 
         [0015]      FIG. 1  illustrates a system  1  in accordance with one or more embodiments. The system  1  includes a plurality of sensors  12  in the rotor blades  10  and the rotor shaft  18 . The sensors  12  may include wireless transmitters to transmit data wirelessly to an antenna  14  and receiver  13 . The sensors  12  may include, for example, strain gauges, magnetic Hall Effect sensors, temperature sensors, pressure sensors, magnetorestrictive sensors, accelerometers, and rate gyros. The sensors  12  may monitor the rotor blades  10  and shaft  18  to sense the loads and motion of the blades  10  and shaft  18 , and the effect of perturbations in the aircraft state on the blades  10  and shaft  18 . Perturbations in aircraft state may result in changes in the loads and motion of the blades  10  and shaft  18  including changes in blade flap, blade pitch, blade lead lag, main rotor shaft bending, main rotor shaft torque, and pitch rod loads, for example. 
         [0016]    In exemplary embodiments, the wireless signals output from the sensors  12  are low-power wireless signals to prevent interference with control systems of the helicopter or to prevent detection of the helicopter from external sensors, such as ground-based receivers or receivers of other aircraft. 
         [0017]    The receiver  13  transmits the sensed rotor data to an analysis unit  15 , which includes a processor  16  to process the sensed data to replace and correct lost and erroneous data to accurately determine the loads and motion of the rotor blades  10 . The analysis unit  15  may further include memory  17 , supporting logic, and other circuitry necessary to analyze the sensor data and store and transmit the analyzed data. Examples of memory and supporting logic include hard disks, flash memory, volatile and non-volatile memory, field programmable gate arrays, multiplexers, and other memory and logic circuitry. According to some embodiments, the analysis unit  15  is located within the body  11  of the helicopter. According to some embodiments, the analysis unit  15  is external to the helicopter. For example, the wireless receiver  13  may include a wireless transmitter, and the wireless transmitter may transmit the sensor data to an external analysis unit. 
         [0018]    The system  1  is illustrative. In some embodiments, alternative forms or types of aircraft configuration may be used without departing from the scope and spirit of this disclosure. 
         [0019]    Referring to  FIG. 2 , a system  200  for transferring power and/or data in accordance with one or more embodiments is shown. In some embodiments, the system  200  may be associated with one or more of the components or devices shown and described above in connection with the system  1  of  FIG. 1 . For example, the system  200  may be associated with one or more of the sensors  12 , the antenna  14 , the receiver  13 , and the analysis unit  15 . 
         [0020]    The power and data transfer base  202  may represent the origin of power or data in the system  200 . Power and data may be conveyed from the base  202  to a device or structure that includes an inductor coil  204  and a capacitance plate  206 . The power and data may be transmitted to a second structure or device that includes an inductor coil  208  and a capacitance plate  210 . The transmission may occur over an air gap  212  that may provide a path for magnetic lines of flux. In this regard the transmission between the first and second structure may be analogous to a magnetic coupling between primary and secondary coils associated with a transformer, wherein a typical laminated iron core has been replaced by the air gap  212 . The power and data may be conveyed from the second structure to a remote power and data sensor  214 , wherein the power and data may be consumed or processed. 
         [0021]    In some embodiments, technology used for data transfer between sensors used in, e.g., health monitoring may adhere to one or more techniques. For example, any commercial or proprietary protocol (e.g., wired protocol), such as RS-232, I 2 C, and Ethernet may be used. In some embodiments, any commercial E-field wireless protocol, such as IEEE 802.15.4, IEEE 802.11x, etc., may be used. 
         [0022]    Referring to  FIG. 3 , a system  300  used for power and data transfer on a hub is shown. The system  300  may include a primary coil, denoted as a gateway loop  302  in  FIG. 3 . The gateway loop  302  may be embedded in the main structure of a rotor hub and may include processing circuitry. The primary coil/gateway loop  302  may provide power to one or more sensors (e.g., passive sensors) or actuators, denoted as sensor loop  304  in  FIG. 3 . The primary coil  302  may receive data transmitted by the sensors  304 . Data that has been successfully demodulated can be transferred to an avionics bay using one or more techniques. The system  300  may be used to transfer power over distances of up to, e.g., 2 meters. 
         [0023]    The physical layer in H-field communications may incorporate aspects of pulse width modulation (PWM). PWM may work well for low data rates and single wireless links. The typical 3 dB bandwidth for H-field communications may be on the order of 4 KHz. For applications in rotating wing aircraft, this bandwidth may be inadequate due to a large number of sensors (e.g., one-hundred discrete sensor units) that may be used. In this respect, frequency division multiplexing (FDM) techniques may be used in a narrow channel, and may be scaled to accommodate a large number of sensors. 
         [0024]    Bulk manufacturing and installation variation techniques may be used to accommodate the large number of sensors. These variations may be captured after installation has occurred and classifications may be adopted to identify a specific center frequency shift of the Q-factor of each individual coil. This may be detected as the designed 3 dB bandwidth is known. Once the individual center frequencies have been quantified, a FDM scheme or algorithm may be used along with PWM to achieve a high data bandwidth.  FIG. 4  represents an example, wherein four frequencies, denoted as f 0 , f 1 , f 2 , and f 3 , are shown as being associated with pairs of data, center frequency (in Hertz), and pulse width (in milliseconds) as follows, respectively: 
         [0025]    f 0 : (00, 2000, 1) 
         [0026]    f 1 : (01, 2000, 2) 
         [0027]    f 2 : (10, 2100, 1) 
         [0028]    f 3 : (11, 2100, 2). 
         [0029]    The values used in connection with  FIG. 4  are illustrative. In some embodiments, different values may be used or present. 
         [0030]    Turning to  FIG. 5 , a flow chart of an exemplary method  500  is shown. The method  500  may execute in connection with one or more components, devices, or systems, such as those described herein. The method  500  may be used to enable wireless power and data transfer capability to sensors embedded in the hub of a rotating wing aircraft. 
         [0031]    In block  502 , one or more sensors (e.g., wireless sensors) or coils may be placed or embedded in a paramagnetic material, such as titanium. As an example, a primary coil may be embedded in a main structure of a rotor hub with processing circuitry. The primary coil may provide power to passive sensors and actuators and may serve as a receiver for data transmitted by sensors. 
         [0032]    As part of block  502 , the sensors or coils may be placed within a common structure. In some embodiments, a coil may be placed in a first structure and sensors may be placed in one or more additional structures; a small air gap may be present between the first structure and the additional structure(s). 
         [0033]    In block  504 , the structure(s) may be coated or sealed following the inclusion of the sensors or coils. In some embodiments, the structure(s) may be built around the sensors or coils using additive manufacturing techniques. 
         [0034]    In block  505 , power may be provided by a coil to the sensors. 
         [0035]    In block  506 , a center frequency shift of the Q-factor for each individual coil may be identified. 
         [0036]    In block  508 , a FDM technique in combination with a PWM technique may be used to obtain a high data bandwidth for data transfer. 
         [0037]    In block  510 , a request for an access credential may be received. If the credential is correct or validated/authenticated, one or more methodological acts, such as those described herein or above, may be enabled. Block  510  may optionally be used in some embodiments to provide for secure access or function with respect to one or more resources. 
         [0038]    The method  500  is illustrative. In some embodiments, one or more of the blocks or operations (or a portion thereof) may be optional. In some embodiments, one or more additional blocks or operations not shown may be included. In some embodiments, the blocks or operations may execute in an order or sequence that is different from what is shown. 
         [0039]    Embodiments of the disclosure may be used to provide for scalable capability without a need for upgrading an installed wiring harness. A new sensor may be added with a small power/data transfer coil. 
         [0040]    Embodiments of the disclosure may provide for a secure network. For example, a magnetic field or H-field may decay at a rate of 60 dB/decade, as compared to 20 dB/decade for an electric field or E-field. As such, use of the H-field for communications may provide protection against jamming or eavesdropping. 
         [0041]    As described herein, in some embodiments various functions or acts may take place at a given location and/or in connection with the operation of one or more apparatuses, systems, or devices. For example, in some embodiments, a portion of a given function or act may be performed at a first device or location, and the remainder of the function or act may be performed at one or more additional devices or locations. 
         [0042]    Embodiments may be implemented using one or more technologies. In some embodiments, an apparatus or system may include one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus or system to perform one or more methodological acts as described herein. Various mechanical components known to those of skill in the art may be used in some embodiments. 
         [0043]    Embodiments may be implemented as one or more apparatuses, systems, and/or methods. In some embodiments, instructions may be stored on one or more computer-readable media, such as a transitory and/or non-transitory computer-readable medium. The instructions, when executed, may cause an entity (e.g., an apparatus or system) to perform one or more methodological acts as described herein. 
         [0044]    Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional.