Abstract:
Systems and methods for embedding a warning signal in a sensor pulse. When a taxi anticollision system of a host aircraft senses a threat headed for the aircraft, a warning signal is embedded in a sensor pulse to warn the offending vehicle that it is in the field of view of the host aircraft&#39;s sensor and is moving on a trajectory that is threatening collision with the host aircraft. Alternately, the radar issues a dedicated pulse for reading and alerting the receiving device.

Description:
PRIORITY CLAIM 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/653,297, filed May 30, 2012, the contents of which are hereby incorporated by reference. This application also claims the benefit of U.S. Provisional Application Ser. No. 61/706,632, filed Sep. 27, 2012, the contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Current methods of receiving a timely warning of impending collision between parked or taxiing aircraft vehicles and a host ground vehicle are costly. These solutions may fail to provide effective warning to the other vehicles. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention provides systems and methods for embedding a warning signal in a sensor pulse. When a taxi anticollision system of a host aircraft senses a threat headed for the aircraft, a warning signal is embedded in a sensor pulse to warn the offending vehicle that it is in the field of view of the host aircraft&#39;s sensor and is moving on a trajectory that is threatening collision with the host aircraft. Alternately, the radar issues a dedicated pulse for reading and alerting the receiving device. 
         [0004]    In one aspect of the invention, the vehicle includes a receiver that, when it receives the coded warning, alerts the driver that caution must be observed. 
         [0005]    In another aspect of the invention, vehicles outside the field of the host aircraft&#39;s sensor do not receive a warning or act on a received warning. The warning is a “broadcast” made to only those receivers in the beam of the sensor (i.e., in the radio transmission field). Other receivers may hear the signal due to multipath reflections, etc.—but a threshold set at the vehicles&#39; receivers will eliminate most of those types of false warning. 
         [0006]    In still another aspect of the invention, the host aircraft&#39;s sensor performs beamshaping to further narrow the field-of-view, thereby reducing the number of detectable vehicles. 
         [0007]    In yet another aspect of the invention, the aircraft&#39;s sensor reads an RFID device embedded in a receiver on the target vehicle and correlates the location of the detected RFID receiver with the exact location returned by the radar (if the radar is so capable). Thus, a warning is issued to only that correlated receiver without sending an alarm to other receivers or operators in the sensor field. 
         [0008]    In still yet another aspect of the invention, the host aircraft system performs beamshaping to narrow the field of the transmitted pulse warning to reduce the number of vehicles that receive the warning. This is different from narrowing for detection. The radar could have a wide field of view for finding threats, but when sending an alert, narrows the alert beam separately from beamforming related to detection. 
         [0009]    In a still further aspect of the invention, the host aircraft system reads an RFID device embedded in the receiver of the target and sends a warning only to that device by using a unique address for that device, thus reducing the number of false alarms or irrelevant alarms sent to the operators of the receivers (drivers and equipment operators). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings: 
           [0011]      FIG. 1  is a block diagram of exemplary systems configured in accordance with an embodiment of the present invention; and 
           [0012]      FIG. 2  is side view of exemplary vehicles equipped with the system shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    As shown in  FIG. 1 , a first vehicle  20  (e.g., taxiing aircraft, ground-based support vehicle, etc.) includes an antenna  24 , a radar processor  30 , a receiver  32 , a transmitter  34 , a radio frequency identification (RFID) tag detection component  38 , and a target detection component  36 . 
         [0014]    The radar components (the radar processor  30 , the receiver  32 , and the transmitter  34 ) generate and emit a radar pulse via the antenna  24 . Based on radar pulse return, the processor  30  detects and determines the coordinates of any obstacles, such as nearby service vehicles. The emitted radar pulse may include a RFID read pulse. The emitted signal reads a passive (unpowered) RFID device  44  that is part of a receiver and alerting device  40  located in/on a second vehicle/device  48 , such as an aircraft, ground personnel, or ground equipment. 
         [0015]    Return signals received at the antenna  24 , the receiver  32 , and the processor  30  are sent to the target detection component  36 . RFID read information included in the received signals is sent to the RFID tag detection component  38 . The components  36 ,  38  may be separate hardware processors, partitioned functions within the processor  30 , or an integrated processing function. The target detection component  36  determines the track of the device  48  and, based on the determined track, determines whether the vehicle/device  48  is on a collision course with the vehicle  20  (i.e., the vehicle  20  is moving or the detected object is moving, or both). Then the processor  30  and/or the tag detection component  38  checks for a correlated RFID tag associated with the second vehicle/device  48  that is on a collision course. If an RFID tag is present, the processor  30  generates an alarm and attaches information associated with the vehicle/device  48  and/or the receiver and alerting device  40  included in the RFID tag to the alarm. The generated alarm is then transmitted. 
         [0016]    The receiving and alerting device  40  includes a receiver antenna  54 , a receiver  56 , a processor  60 , an output device  62 , and a passive RFID antenna  52  connected to the RFID device  44 . The RFID antenna  52  and the RFID device  44  may be included in a single integrated package. The RFID device  44  and the RFID antenna  52  provide identity information of the device  40  and or the device  48  when the vehicle  20  issues the read pulse. 
         [0017]    RFID devices are configured to be passive. For example, the RFID device alters the reflected pulse from a passively received radar or radio pulse signal. Range for reading an RFID device is determined by the beampattern of the transmitter/receiver of the querying device. 
         [0018]    One of ordinary skill in RFID design will be to balance the power of the radar pulse transmissions with the size of the passive antenna on the RFID device without undue experimentation to insure there is enough “target corss section” to capture and return the ID signal. 
         [0019]    In one embodiment, when the receiver  56  is off, the processor  60  shorts the RFID device  44 , thereby removing the ability to be read. When the receiver  32  and the processor  30  do not receive RFID information (RFID number (ID)) in response to a read pulse, the processor  30  determines that it cannot send a receiver-specific warning to the device  40 . When the receiver  56  is on, the RFID device  44  communicates its RFID number to the processor  60 . The processor  60  keeps the RFID device  44  active as a result of the receiver&#39;s  56  being on. The antenna  54  and the radar pulse receiver  56  receive incoming warnings with identification information (ID) and send them to the processor  60 . The processor  60  correlates the ID in the received warning with the RFID ID of the RFID device  44  to determine if the warning is for the device  40 . If the warning is meant for the device  40 , the processor  60  generates an alarm signal that is sent to the output device  62 . In response to receiving the alarm signal, the output device  62  produces an audio, a visual, and/or a haptic alarm. The type of output device alarm is based on a user&#39;s selection. 
         [0020]    The RFID receiving and alerting device  40  may be:
       carried in a shirt pocket;   clipped, mounted, or bonded to the vehicle (e.g., aircraft or ground support vehicle dashboard or windshield); and/or   implemented in an electronic flight bag or comparable device (e.g., cell phones, tablet computer (Ipad)).       
 
         [0024]    Alerts may be one or more of the following:
       haptic (vibration or other touch sense);   audio (alarms, voice warning); and/or   visual (flashing light, strobe, rotating light, etc.).       
 
         [0028]      FIG. 2  shows a taxiing aircraft  100  that includes the components included in the vehicle  20  shown in  FIG. 1 . In one embodiment, the aircraft  100  includes a radar transceiver at the wingtip(s) that generates a read pulse. The generated read pulse is received at any proximate other vehicles, such as a service vehicle  110  that includes the receiving and alerting device  40 . In response to receiving the read pulse, the receiving and alerting device  40  in the service vehicle  110  includes RFID information in a return signal generated as a result of receiving the read pulse. If the system within the aircraft  100  determines that the service vehicle  110  poses a collision threat, a warning signal that includes the RFID information for the service vehicle  110  is generated and transmitted. When the service vehicle  110  receives the warning signal, it determines that the warning signal is for the service vehicle  110 , based on the RFID information, and outputs an alert to the operator of the service vehicle  110  as a result. 
         [0029]    In one embodiment, the present invention is integrated into a radar-based anticollision system (ACS) designed to protect an entire aircraft, or various components, such as wingtips or engines. The hosting ACS may be a comprehensive protection system or may be directed at only partial coverage, such as wingtips or engine nacelles. 
         [0030]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.