This disclosure relates generally to a system and method for data retransmission through radio-frequency (RF) opaque barriers.
It is difficult to transmit RF information into or out of many types of metal or carbon fiber enclosures (or partial enclosures), such as a fuel tank (e.g., a complete enclosure) or an aircraft wheel well (e.g., a partial enclosure), because such the metal or carbon fiber wall forming such enclosure may act as a Faraday cage to block the transmission of RF signals into or out of that enclosure. In many cases, however, it is necessary to place an information source such as a sensor within such an enclosure, e.g., a sensor for measuring the amount of fuel remaining within a fuel tank. Although wires may be provided through an aperture in the metal or carbon fiber wall forming the enclosure, such apertures may provide a pathway for contamination or leakage and long runs may be needed for the wiring for each sensor. Furthermore, many common methods of transmitting data in low power and low data rate applications make use of the 2.4 to 2.4835 GHz frequency band (e.g., signals using the ZigBee protocol according to IEEE Standard 802.15.4). Signals transmitted in this frequency band have a wavelength of nearly five inches, which means that any metal or carbon fiber wall having openings which are only less than five inches in diameter will be RF opaque and prevent such type of signals from passing through such enclosure.
In addition, given the nature of such enclosures, which may be a fully-encased enclosure like a fuel tank or a partially-encased enclosure like an aircraft wheel well, power may be available on only one side of such enclosure. In the case of a fuel tank, for example, power wiring may be available or desired only on the outside the fuel tank. In the case of an aircraft wheel well, power wiring may be available or desired only within the wheel well. Since, as discussed above, it is preferable that no aperture be used through the metal or carbon fiber wall forming such an enclosure, power would thus be available only for a transmitter on one side of the wall but not a re-transmitter on the other side of the wall (or vice versa).
Accordingly, there is a need for a system and method of data transmission and/or retransmission which overcomes the problems recited above.
In a first aspect, a system for transmitting a first information signal through a radio-frequency opaque barrier is disclosed. The system includes a transmitter positioned on a first side of and in close proximity to the radio-frequency opaque barrier. The transmitter includes a vibration generator that converts an electrical signal received on an input to a corresponding vibration signal. The transmitter also includes a controller that is coupled to the input of the vibration generator and which receives a first information signal, modulates the first information signal with a first carrier signal to produce a modulated first information signal, and forwards the modulated first information signal to the input of the vibration generator. The system also include a re-transmitter positioned on a second side of and in close proximity to the radio-frequency opaque barrier. The second side of the radio-frequency opaque barrier is opposite the first side thereof. The re-transmitter includes an accelerometer that detects vibration signals and produces an electrical signal on an output corresponding to the detected vibration signals. The re-transmitter also includes a controller that is coupled to the output of the accelerometer and which receives the electrical signal from the output of the accelerometer and demodulates the first information signal included within the electrical signal received from the output of the accelerometer.
In a second aspect, a method for transmitting a first information signal through a radio-frequency opaque barrier is disclosed. A first information signal is modulated with a first carrier signal to produce a modulated first information signal in a first device positioned on a first side of and in close proximity to the radio-frequency opaque barrier. The modulated first information signal is converted to a corresponding first vibration signal in the first device. The first vibration signal is detected in a second device positioned on a second side of and in close proximity to the radio-frequency opaque barrier to produce a detected first vibration signal. The second side of the radio-frequency opaque barrier is opposite the first side thereof. The detected first vibration signal is converted to a first electrical signal in the second device. Finally, the first information signal included within the first electrical signal is demodulated in the second device.
In a third aspect, a system for transmitting energy through a radio-frequency opaque barrier is disclosed. The system includes a first device positioned on a first side of and in close proximity to the radio-frequency opaque barrier. The first device includes a vibration generator that converts an electrical signal received on an input to a corresponding vibration signal. The first device also includes a controller that is coupled to the input of the vibration generator and which forwards a predetermined signal to the input of the vibration generator. The system also include a second device positioned on a second side of and in close proximity to the radio-frequency opaque barrier. The second side of the radio-frequency opaque barrier is opposite the first side thereof The second device includes a vibration energy harvester device that generates an electrical signal on an output corresponding to detected vibration signals. The second device also includes an energy storage device coupled to the output of the vibration energy harvester device which is charged by the electrical signal received from the output of the vibration energy harvester device and supplies electrical power for the second device.
In a fourth aspect, a method for transmitting energy through a radio-frequency opaque barrier is disclosed. A predetermined electrical signal is converted to a corresponding vibration signal in a first device positioned on a first side of and in close proximity to the radio-frequency opaque barrier. The vibration signal is detected in a second device to produce a detected vibration signal and the detected vibration signal is converted to a corresponding electrical signal. The second device is positioned on a second side of and in close proximity to the radio-frequency opaque barrier. The second side of the radio-frequency opaque barrier is opposite the first side thereof. An energy storage device in the second device is charged using the corresponding electrical signal converted from the detected vibration signal.
The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings.
The following detailed description, given by way of example and not intended to limit the present disclosure solely thereto, will best be understood in conjunction with the accompanying drawings in which:
Each figure shown in this disclosure shows a variation of an aspect of the embodiments presented, and only differences will be discussed in detail.
In the present disclosure, like reference numbers refer to like elements throughout the drawings, which illustrate various exemplary embodiments of the present disclosure.
Referring now to
Re-transmitter 120 is coupled to (and powered by) a power source 130 which is available outside of enclosure 105 but, due to the nature of enclosure 105 but which cannot be coupled into enclosure 105. Re-transmitter 120 includes a controller 123 that is coupled to a vibration generator 121 and to an accelerometer 122. Controller 123 is configured to generate a carrier signal that is supplied to vibration generator 121. Vibration generator 121 generates a vibratory signal 140 based on the carrier signal received from controller 123 which vibratory signal 140 is applied to the adjacent wall of enclosure 105. In a further embodiment where information signals are to be transmitted to transmitter 112 and/or information source 110, controller 123 may modulate such information signals with the carrier signal and provide the modulated signal to vibration generator 121. In this latter case, the vibratory signal 140 applied to the wall of enclosure 105 is based on the modulated signal. Accelerometer 122 is configured to detect a separate vibratory signal 141 (discussed below) and to convert such vibratory signal 141 into an electrical signal that is provided to controller 123. Controller 123, in turn, is configured to receive the converted electrical signal, to demodulate information signals included therein from the base carrier signal, and to forward the demodulated information signals to a higher level control system for further processing or usage. As one of ordinary skill in the art will readily recognize, re-transmitter 120 may forward the demodulated information signals wirelessly, via antenna 124, or alternatively via a wired interface (not shown in
Transmitter 112 includes a controller 115 that is coupled to a vibration generator 114 and to an accelerometer 113. Transmitter 112 also includes a vibration energy harvester device 117 that is coupled to an energy storage device 116 (e.g., a battery or a capacitor) and is configured to detect vibratory signal 140 (generated on an opposite side of the wall forming enclosure 105 by re-transmitter 120) and to convert such vibratory signal 141 into an electrical signal that is used to charge the energy storage device 116. Vibration energy harvester device 117 may convert vibrations to electrical energy using one or more of the following technologies: piezoelectric, electromagnetic, electrostatic (capacitive), and magnetostrictive. Energy storage device 116 is configured to provide all the power necessary to operate transmitter 112 and may also be used to power information source 110 in some cases. Accelerometer 113 is only necessary in the further embodiment where information signals are transmitted from re-transmitter 120 to transmitter 112. Accelerometer 113 is configured to detect vibratory signal 140 and to convert such vibratory signal 140 into an electrical signal that is provided to controller 115. Controller 115, in the further embodiment, is configured to monitor the converted vibratory signal, to demodulate any information signals included therein from the base carrier signal, and, in some cases, to forward such demodulated information signals to information source 110. The demodulated information signals may consist of configuration information for transmitter 112 and/or configuration information for information source 110. Controller 115 is also configured to receive an information signals from information source 110, to modulate such information signals with a carrier signal, and to forward the modulated information signals to vibration generator 114. In the event that transmitter 112 receives analog signals from information source 110, controller 115 is also configured to convert such analog signals to digital form as well. Vibration generator 114 converts the modulated information signals from an electrical signal to the vibratory signal 141 that is processed and forwarded by re-transmitter 120 on the opposite side of the wall forming enclosure 105.
Referring now to
Referring now to
Transmitter 312 is mounted inside of enclosure 305 and is coupled to (and powered by) a power source 330 which is available inside of enclosure 305. However, due to the nature of enclosure 305, power source 330 cannot be coupled to the point available immediately outside of enclosure 305 where re-transmitter 320 is mounted outside of the wall forming enclosure 305. Transmitter 312 includes a controller 315 that is coupled to a vibration generator 314 and may also be coupled to an accelerometer 322 in a further embodiment which allows information signals to be transferred from re-transmitter 320 to transmitter 312. In this further embodiment, accelerometer 313 is configured to detect a vibratory signal 340 (discussed below) and to convert such signal 340 into an electrical signal. Controller 315 receives the converted vibratory signal and demodulates the information signals included therein from a base carrier signal, and, if necessary, to forward such demodulated information signals to information source 310. The demodulated information signals may consist of configuration information for transmitter 312 and/or for information source 310. Controller 315 also receives information signals from information source 310, modulates such information signals with a carrier signal, and forwards the modulated information signals to vibration generator 314. In the event that transmitter 312 receives the information signals from information source 310 in analog form, controller 315 also to converts such analog signals to digital form as well. Vibration generator 314 converts the modulated information signals from an electrical signal to vibratory signal 341 that is applied to the inner wall of enclosure 305.
Re-transmitter 320 includes a controller 323 which is coupled to an accelerometer 322 and, in the further embodiment discussed above, to a vibration generator 321. Re-transmitter 320 also includes a vibration energy harvester device 326 which is coupled to an energy storage device 325 and is configured to detect the vibratory signal 341 (discussed above) and to convert such vibratory signal 341 into an electrical signal that is used to charge energy storage device 325. Vibration energy harvester device 117 may convert vibrations to electrical energy using one or more of the following technologies: piezoelectric, electromagnetic, electrostatic (capacitive), and magnetostrictive. Energy storage device 325 provides all the power necessary to operate re-transmitter 320. Accelerometer 322 is configured to detect vibratory signal 341 and to convert such vibratory signal 341 to an electrical signal that is provided to controller 323. Controller 323 is configured to receive the electrical signal output by accelerometer 322 and demodulate the information signals included within that signal from the base carrier signal, and to forward the demodulated information signals to a higher level control system for further processing or usage. As with system 100 in
Referring now to
In the systems shown in
Although the present disclosure has been particularly shown and described with reference to the preferred embodiments and various aspects thereof, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the disclosure. It is intended that the appended claims be interpreted as including the embodiments described herein, the alternatives mentioned above, and all equivalents thereto.