Abstract:
Systems and methods for collision avoidance are disclosed. In one embodiment, a method includes providing a proximity warning system operatively coupled to the aircraft and adapted to monitor a scanning area proximate a selected portion of the aircraft. The scanning area is monitored using the proximity warning system. A ground-based device within the scanning area is detected using the proximity warning system, and a distance between the ground-based device and the selected portion on the aircraft is determined using the proximity warning system. If the distance between the ground-based device and the selected portion does not exceed a selected minimum distance, then a warning signal is provided. In alternate embodiments, the proximity warning system provides a second warning signal distinguishable from the warning signal.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to collision avoidance systems, and more specifically, to systems and methods for collision avoidance between aircraft and ground-based service equipment.  
       BACKGROUND OF THE INVENTION  
       [0002]     Passenger aircraft generally require the performance of a variety of different tasks following the termination of a specific flight. Typically, the aircraft must be refueled, cargo must be unloaded, the cabin of the aircraft must be cleaned, the lavatory wastewater must be removed, and the galley must be re-provisioned, among other tasks. Consequently, during the performance of various ground service operations, a plurality of service vehicles may be maneuvering and/or positioned about the aircraft. A risk therefore exists that a service vehicle may inadvertently collide with a portion of the aircraft while moving about the aircraft. Such a collision may result in significant damage to the aircraft, requiring a costly and time-consuming repair before the aircraft is returned to service.  
         [0003]     Since non-metallic composite components are increasingly replacing conventional metallic structures on passenger aircraft in order to reduce weight, the likelihood that significant damage may result from a ground service vehicle collision has accordingly increased. Moreover, selected portions of the aircraft are particularly susceptible to damage while the aircraft is positioned on the ground. For example, landing gear doors, cargo loading doors and passenger access doors are generally maintained in an open position during ground operations, and may be relatively easily damaged by even a minor collision. Even in cases where damage to the aircraft is less significant, relatively expensive flight delays are often incurred since a mandated inspection of the damaged area must be performed to determine if the damage is within allowable limits.  
         [0004]     One conventional method of reducing the possibility of undesirable collisions is to increase the minimum clearance criteria around the aircraft for vehicle maneuver. For example,  FIG. 1  is a top elevational view of an aircraft  100  being serviced by ground support vehicles in accordance with the prior art. The aircraft  100  includes a fuselage  102  having left and right forward doors  104 ,  106  positioned ahead of the wings  108 , and a left rear door  110  positioned aft of the wings  108 . In operation, a passenger loading bridge  114  passes an engine  112  positioned on the left wing  108  by a critical clearance  116  as it approaches the left forward door  104  to load and unload passengers. Similarly, a first galley truck  118  passes an engine  112  positioned on the right wing  108  by the critical clearance  116  as it approaches the right forward door  106 , and a second galley truck  120  passes a trailing edge flap of the left wing  108  by the critical clearance  116  as it approaches the left rear door  110 .  
         [0005]     A conventional minimum clearance  116  between the wing  108  of an aircraft  100  and a galley truck  120  maneuvering behind it to dock at the left rear door  110  of the aircraft  100  is presently 3 feet. Due to the increased costs associated with the repair of composite wing structures, however, a conventional approach to reducing the possibility of collision is to increase this minimum clearance, for example, to 5 feet. Unfortunately, merely increasing the minimum clearance criteria around the aircraft may lead to additional difficulties and expense, and may render some equipment and facilities unusable. For example, door  110  may become out of reach by the second galley truck  120  approaching it from behind the wing trailing edge. Accordingly, improved systems and methods for reducing the possibility of collision between a ground service vehicle and an aircraft without increasing the minimum clearance criteria would be beneficial.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention is directed to systems and methods for collision avoidance between aircraft and ground-based service equipment. Embodiments of apparatus and methods in accordance with the present invention may advantageously reduce the possibility of collision between a ground service vehicle and an aircraft without increasing the minimum clearance criteria, thereby reducing costs associated with repairs and enabling the use of conventional ground-based servicing equipment and facilities. Thus, embodiments of the present invention allow a door, such as galley door  110  shown in  FIG. 1 , to be serviceable without moving the door aft.  
         [0007]     In one embodiment, a method of reducing a likelihood of a collision between an aircraft and a ground-based device includes providing a proximity warning system operatively coupled to the aircraft and adapted to monitor a scanning area proximate a selected portion of the aircraft. The method further includes monitoring the scanning area using the proximity warning system, and moving the ground-based device into the scanning area. The ground-based device is detected within the scanning area using the proximity warning system, and a distance between the ground-based device and the selected portion on the aircraft is determined using the proximity warning system. If the distance between the ground-based device and the selected portion falls below a selected minimum distance, then a warning signal is provided. In alternate embodiments, the proximity warning systems includes a laser scanning system, a laser radar system, a laser-based imaging system, a laser radar system, an infrared global positioning system, and a laser-based point tracking system 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings:  
         [0009]      FIG. 1  is a top elevational view of an aircraft being serviced by ground support vehicles in accordance with the prior art;  
         [0010]      FIG. 2  is a schematic view of a collision avoidance system in accordance with an embodiment of the invention; and  
         [0011]      FIG. 3  is a top elevational view of an aircraft equipped with a plurality of collision avoidance systems in accordance with another embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     The present invention relates to systems and methods for collision avoidance between aircraft and ground-based service equipment. Many specific details of certain embodiments of the invention are set forth in the following description and in  FIGS. 2-3  to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the present invention may have additional embodiments, or that the present invention may be practiced without several of the details described in the following description.  
         [0013]     Generally, embodiments of systems and methods in accordance with the present invention may accurately measure the clearance between a moving service vehicle or other ground-based equipment and an aircraft stationed on the ground, and may assist an operator of the ground-based equipment with maintaining a minimum clearance and avoiding a collision with the aircraft. In one particular embodiment, when the critical clearance (e.g. 3 feet) is reached, a system in accordance with the invention will warn the operator that the minimum clearance has been reached.  
         [0014]      FIG. 2  is a schematic view of a collision avoidance system  200  in accordance with an embodiment of the invention. In this embodiment, the collision avoidance system  200  includes a laser scanner  202  having a controller  204  operatively coupled to a laser rangefinder  206  and to a warning indicator  208 . A scanning assembly  210  is adapted to receive a laser beam  212  emitted by the laser rangefinder  206 , and to transmit, reflect, or refract the laser beam  212  over a scanning area  214 . In one particular embodiment, the scanning assembly  210  includes a rotating polygonal refractive lens.  
         [0015]      FIG. 3  is a top elevational view of an aircraft  300  equipped with a plurality of collision avoidance systems  200 . In this embodiment, the scanners  202  are located at the origin of each scanning area  214 , and the warning indicators  208  (e.g. flashing lights) are located near the doors of the aircraft  300  to warn the drivers of approaching vehicles if their vehicle gets too close to a respective portion of the aircraft  300 . With the exception of the collision avoidance systems  200 , the aircraft  300  includes components and subsystems generally known in the pertinent art, and in the interest of brevity, will not be described in detail. As shown in  FIG. 3 , the aircraft  300  generally includes one or more propulsion units  302  that are coupled to wing assemblies  304 , or alternately, to a fuselage  306  or even other portions of the aircraft  300 . A tail assembly  308  is coupled to the fuselage  306 , and a flight control system  312  is operatively coupled to the propulsion units  302 , the wings  304 , and the tail assembly  308 . Additionally, the aircraft  300  includes a host of other systems and subsystems generally required for the proper operation of the aircraft  300 .  
         [0016]     Although the collision avoidance systems  200  are depicted in the embodiment shown in  FIG. 3  as being coupled to the fuselage  306 , in alternate embodiments, the systems  200  may be positioned at any desired location on the aircraft  300 . For example, in alternate embodiments, the collision avoidance systems  200  may be positioned on the wings  304 , the propulsion units  302 , the tail assembly  308 , or any other suitable portion of the aircraft  300 .  
         [0017]     The aircraft  300  shown in  FIG. 3  is generally representative of a commercial passenger aircraft, such as the 7E7 aircraft commercially-available from The Boeing Company of Chicago, Ill. In alternate embodiments, however, collision avoidance systems  200  in accordance with the present invention may be incorporated onto a wide variety of aircraft types, including military aircraft, cargo aircraft, rotary aircraft, and any other desired flight vehicles. Examples of such flight vehicles may include those aircraft described, for example, in Jane&#39;s All The World&#39;s Aircraft, available from Jane&#39;s Information Group, Ltd. of Coulsdon, Surrey, UK.  
         [0018]     With reference to  FIGS. 2 and 3 , in operation, the controller  204  of each of the laser scanners  200  transmits a first control signal to the laser rangefinder  206  to initiate the laser beam  212 . The laser beam  212  is directed by the scanning assembly  210  over the scanning area  214 . When an object  216  (e.g. a galley truck, a luggage mover, a fuel truck, a passenger loading bridge, etc.) enters the scanning area  214 , reflected light  218  is reflected from the object  216  back to the laser rangefinder  206 . The laser rangefinder  206  then determines the distance from a suitable reference point (e.g. the laser scanner  202 ) to the object  216  and transmits corresponding range indication signals to the controller  204 . Alternately, the laser rangefinder  206  may simply transmit the range indication signals to the controller  204 , and the controller  204  may determine the corresponding distance. After the distance from the reference point to the object  216  is determined, the controller may transmit a corresponding warning control signal to the warning indicator  208 . The warning indicator  208  may then provide a visual warning, an audible warning, or both, to indicate the position of the object  216  within the scanning area  214  or relative to the reference point.  
         [0019]     For example, in one embodiment, the warning indicator  208  provides a flashing light that begins when the object  216  is determined to be at a first selected distance (e.g. 3 feet) from the reference point, and provides a constant light when the object  216  reaches a second selected distance (e.g. 2 feet) from the reference point. In various embodiments, the reference point may be a location on one of the propulsion units  302 , on the trailing edge of the wing  304 , or any other desired portion of the aircraft  300 . Thus, when the warning indicator  208  is flashing, the operator of a ground-based service vehicle or other apparatus operating in proximity to the aircraft  300  will be alerted to the fact that they are operating within the first selected distance from the specified portion of the aircraft  300 , and may take extra precautions to avoid a collision.  
         [0020]     More specifically, the operator of the passenger loading bridge  114  ( FIG. 1 ) approaching the left forward door  104  may be alerted by the flashing warning indicator  108  that they have reached the critical clearance  116  between the passenger loading bridge  114  and the left propulsion unit  302 . Similarly, the operator of the first and second galley trucks  118 ,  120  ( FIG. 1 ) approaching the right forward door  106  and the left rear door  110 , respectively, may be alerted by the flashing warning indicator  208  that they have reached the critical clearance  116  between the first and second galley trucks  118 ,  120  and the right propulsion unit  302  and the trailing edge of the left wing  304 , respectively. When the warning indicators  108  show a constant illuminated (or audio) signal, the operators of the various ground-based vehicles may know that they are operating within a second selected distance, and may take appropriate action, such as stopping, making corrective maneuvers, seeking assistance from other ground personnel, or any other suitable action.  
         [0021]     It will be appreciated that the laser scanner  202  ( FIG. 2 ) may be any suitable type of laser scanner, including, for example, those systems commercially-available from Mensi, Inc. of Alpharetta, Ga. In alternate embodiments, however, the laser scanner  202  may be replaced with an alternate type of distance-determining device. For example, in alternate embodiments, the laser scanner  202  may be replaced with a laser radar system of the type generally disclosed, for example, in U.S. Pat. No. 5,202,742 issued to Frank et al., U.S. Pat. No. 5,266,955 issued to Izumi et al., and U.S. Pat. No. 5,724,124 issued to Kai, which patents are incorporated herein by reference. Alternately, a laser-based imaging system may be used, such as the Cyrax laser imaging system, commercially-available from Cyra Technologies, Inc. of San Ramon, Calif. In a further embodiment, a laser radar system may be used, including, for example, the LR200 laser radar system, commercially-available from Leica Geosystems, Inc. of Heerbrugg, Switzerland. In other embodiments, the distance-measuring device may be an infrared global positioning system (IRGPS), including those systems generally disclosed, for example, in U.S. Pat. No. 5,589,835 issued to Gildea et al., U.S. Pat. No. 6,452,668 B1, issued to Pratt, and U.S. Pat. Nos. 6,501,543 B2, 6,535,282 B2, 6,618,133 B2, and 6,630,993 B1 issued to Hedges et al., which patents are incorporated herein by reference. Such IRGPS systems are commercially-available from, for example, ARC Second, Inc. of Dulles, Va. Alternately, the distance-measuring device may be a laser-based point tracking system of the type commercially-available from Automated Precision, Inc. of Rockville, Md., or any other suitable type of distance-measuring device.  
         [0022]     Embodiments of systems and methods in accordance with the present invention may provide significant advantages over the prior art. For example, because the possibility of collisions between aircraft and ground-based vehicles is reduced, the costs associated with repairs, delayed flights, and dissatisfied customers is reduced. Furthermore, these desired results may be achieved without increasing the minimum clearance criteria around the aircraft, thereby allowing the use of conventional ground-based equipment and facilities.  
         [0023]     While preferred and alternate embodiments of the invention have 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 these preferred and alternate embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.