AIRCRAFT POSITION INDICATION SYSTEM FOR AIRCRAFT PASSENGERS

Abstract: A system for indicating to aircraft passengers the approximate location of the aircraft. The system includes the aircraft navigation equipment (10), adapted to generate navigation signals indicative of the aircraft's position. A computer (20) receives the navigation signals and is adapted to correlate the aircraft position to a particular sector of a map (60) of the ground area to be overflown during the flight. The computer (20) generate a display signal indicative of the particular map sector. One or more visual display units (40) are mounted in the aircraft passenger compartment and are coupled to the computer. The display unit (40) provides a visual identification of the map sector then being overflown. Passengers may be provided with maps and map overlays which divide the map into predetermined sectors. By correlating the visual information to the map, the passenger may determine the approximate location of the aircraft, and hence identify visible landmarks, follow the aircraft's movement and so on. The computer may also control an audio message unit (50), coupled to the aircraft audio system (55) and adapted to issue predetermined audio messages in dependence upon the particular map sector being overflown.

Description: AIRCRAFT POSITION INDICATION SYSTEM FOR AIRCRAFT PASSENGERS 1. FIELD OF THE INVENTION The field of the present invention is apparatus for indicating the position of an aircraft, and more particu¬ larly, apparatus for indicating to aircraft passengers the approximate position of the aircraft. 2. BACKGROUND OF THE INVENTION Passengers on commercial aviation flights are often interested in following the aircraft's relative position during the flight in order to determine the identity of landmarks on the ground which are visible during the flight", or for various other reasons, such as simply to follow the aircraft's flight, to estimate the remaining length of flight time, and so on. At the present time, the ordinary way the passenger may be apprised of the identities of the landmarks or the aircraft's position relative to ground is from one of the aircraft flight crew, who either recognizes the landmark or, knowing the aircraft's position from navigation equipment, correlates the position to maps of the land being overflown. The aircraft position is, of course, available from data from the navigation equipment on commercial aircraft. Such information is typically only infrequently relayed by the flight crew to the passengers, inasmuch as the crew's attention is understandably directed to their primary flight duties. There is, therefore, a perceived need to furnish aircraft passengers with aircraft position data regularly lE OMP during the flight, and without continuus involvement from the aircraft crew during the flight. It is a principle object of the present invention to fulfill this need. .Another object of the present invention is to provide a controllable system for providing passengers with position data so that only those passengers desiring to have the capability to determine the approximate location of the aircraft may take advantage of the system. Further objects of the present invention are to provide a system for indicating the approximate location of an aircraft which is reliable, simple to operate, and readily adaptable to different types of aircraft and naviga¬ tion equipment. SUMMARY OF THE INVENTION These and other objects are achieved by the invention described herein. The invention comprises a system for indicating the approximate position of an aircraft relative to a map of the area being overflown. The system includes navigation equipment adapted to generate navigation signals indicative of the aircraft's position, which may comprise latitude, longitude, ground speed and aircraft heading. The navigation signals are coupled to a system computer which has been programmed with map sector data corresponding to maps of the ground area to be overflown during the particu- lar flight. The computer is programmed to correlate the particular navigation signals with the corresponding map sector, and generate a display signal indicative of the particular map sector. The display signal is coupled to a visual display for displaying the map sector identification to the passengers. The passengers may be provided with a map and a transparent grid overlay. The overlay is divided into a plurality of numbered sectors, and is placed over the appropriate map. The passenger correlates the sector identification to the corresponding grid overlay sector to determine the approximate aircraft position. Referring now to Figure 1, a block diagram of the position indication system of the preferred embodiment is disclosed. Block 10 represents the aircraft navigation equipment which is adapted to generate position signals for coupling to computer 20 via line 15. One function of computer 10 is to convert the position signals into a display signal indicative of the map sector position of the aircraft relative to map 50. The computer 10 is provided with initialization means 30 to provide the computer means 10 with data indicative of the aircraft's general flight plan, i.e., its start and destination points, as well as its expected flight path, via line 32. The initialization means 30 may also provide the computer 20 with data indicative of the particular reference map 50. The display signal generated by the computer means 20 is provided to display 40 via line 24. Display 40 is adapted to provide a visual indication to one or more of the aircraft passengers, correlating the aircraft's present position to map means 50. In the preferred embodiment, tKe land area depicted by map 50 is divided into a plurality of predetermined sectors identifiable by unique sector numbers, and the display signal comprises a numerical signal repre¬ senting the particular map sector over which the aircraft is presently flying. Computer 20 is also coupled to audio message unit 50, which is adapted to generate prerecorded audio messages in dependence upon control signals from computer 20 via line 26. Unit 50 is in turn coupled to the aircraft's audio system or network 55 for playback to the passengers. The aircraft navigation equipment represented by block 10 comprises substantially the same equipment already in existence on the aircraft. The specific type of navigation equipment, of course, depends upon the particular aircraft. It is anticipated that the types of navigation equipment fall generally into two types or classes, those systems A further aspect of the present invention is the provision of an audio or visual message playback means having a plurality of predetermined audio or visual messages corresponding to particular ones of the map sectors. Under computer control, the message unit may generate a predeter¬ mined audio or visual message to the passengers, which may, for example, be an information message describing the landmarks in the map sector over which the aircraft is currently passing. Other features and improvements are illustrated. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram illustrating the elements of the preferred embodiment of the present invention. Figure 2 is a flow chart illustrating a computer program for programming the computer of the preferred embodiment. Figure 3 is an illustration of a typical transparent grid overlay with individual sector numbers. Figure 4 is an illustration of a typical map and grid overlay such as may be used in connection with the preferred embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention comprises a novel aircraft position location system for aircraft passengers. The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiment will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications. Thus, the present invention is not intended to be limited to the embodiment shown, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. OMPI which provide position data comprising the latitude and longitude of the aircraft position, and those types of navigation systems which may be generally referred to as "VOR/DME" systems, which employ the VOR omnidirectional radio beacons which are dispersed throughout the United States, each tuned to a predetermined frequency. The first class of equipment is presently found on the larger commercial aircraft, such as, for example, the Boeing 747 aircraft, the MacDonnell Douglas DC-10 and the Lockheed L-1011 aircraft. Such aircraft have advanced inertial navigation systems or the "OMEGA" guidance system, which provide the flight crew with up-to-date latitude and longi¬ tude position data, indicating the current position of the aircraft. The second class of navigation equipment is the VOR/DME system equipment, which is typically used by commer¬ cial aircraft which are designed to make intra-continental flights and, therefore, are able to utilize the omni¬ directional beacons which are disposed around the United States. These types of navigational systems and equipment are well known to those skilled in the art and need not be described in detail here. In general, it is understood that these navigational systems provide information allowing the flight crew to determine the aircraft position relative to a particular radio beacon. By distinguishing each radio beacon and knowing the exact position of the beacon and the aircraft position relative thereto, the aircraft's position may be calculated. Further information about aircraft navigation, naviga- tion equipment and systems is contained in the Advisory Circular No. 90-45A, "Approval of Area Navigation Systems for Use in the U.S. National Airspace System," issued by the Federal Aviation Administration of the Department of Trans¬ portation. Since the first class of navigation equipment is understood to indicate the latitude and longitude of the aircraft's present position, this information is available from equipment 10 and may be readily provided to computer 20. The signals generated by the second common class of equipment, the VOR/DME equipment, are understood to generate signals indicative of the aircraft's position relative to a particular VOR beacon. These signals may be provided to the computer 20, together with a signal indicative of the identity of the beacon. The latitude and longitude of each VOR beacon in the United States, for example, may be stored in the computer memory. From this information and the relative position data, the aircraft position may be cal¬ culated or approximated. The aircraft's speed and .heading may also be provided to computer 20, and the approximate position may be calculated by dead reckoning, i.e., making calculations of time, speed, directions and distance to predict the movement of the aircraft. The precise details by which the aircraft position data is generated and provided to the computer, per se, performs no part of the present invention. It will be readily appreciated by those skilled in the art that many ways of generating the information and tapping the existing aircraft equipment may be utilized. Still referring to Figure 1, the required capability of computer 20 will depend to some extent upon the types of position data which are provided by equipment 10. Thus, for example, the inertial navigation type equipment is under¬ stood to provide latitude and longitude data indicating the aircraft position, whereas the VOR/DME equipment is under¬ stood to provide relative position data and, hence, requires intermediate computational steps, correlating the aircraft's position relative to a VOR radio beacon, determining the latitude and longitude of the radio beacon and then perform- ing a calculation to arrive at the latitude and longitude of OMPI the aircraft. Thus, it is expected that the computer means 10 required for inertial navigation equipment will not have the same memory or computational requirements as required for the VOR/DME equipment. In the preferred embodiment, there is an initializa¬ tion procedure whereby the computer means 10 is programmed in accordance with the expected itinerary of the aircraft. As will be described in more detail hereinbelow, the overall function of the computer is to correlate the position data received on line 15 into display signals which are indica¬ tive of the particular map sector over which the aircraft is flying. The computer will typically be programmed with the particular flight information, as well as the particular map sector information. It is well within the skill of the computer programmer to determine appropriate programs for computing the output signals, as will be described in somewhat greater detail hereinbelow. Referring now to Figure 2, a flow chart is illustrated which indicates the steps of an exemplary program for controlling the operation of computer 10. At step 100, trip data is input, indicative of the trip start point, destina¬ tion and anticipated flight path. For scheduled commercial flights, such information is useful to minimize the burden on the computer, since with this flight information for that area expected to overflown, a defined part of the conti¬ nental United States, for example. At step 105, data respecting the characteristics of the particular map 60 is input to computer 20. This map data may comprise, for example, information defining the sectors into which map 60 is divided. One simple way of defining the sector is by latitude and longitude. For example, lines indicating integral degrees of latitude and longitude define a grid which may be superposed over map 60, with the map sectors each defined by two longitude and two latitude lines. It is then a relatively simple computational step to correlate the current latitude and longitude position of the aircraft to the corresponding sector of map 60 in which the aircraft position is located. To increase the resolution of the system, the number of lines defining the grid may be increased, for example, by defining the grid in steps of one-half degree positions of longitude or latitude. Means for loading the data in steps 100 and 105 are well known to those skilled in the art and could comprise, for example, a cassette tape or floppy disk drive, or a keyboard for allowing a member of the flight crew to input data. These steps could be eliminated if the capacity of computer 10 is sufficient to store all information necessary to correlate aircraft position to the map sectors for a sufficiently large area encompassing the expected flight paths for the aircraft, for example, the continental United States or North America. At step 110, the computer initializes the display 40 to indicate a display signal for the trip start point, which is continuously displayed until the flight commences. After it is determined that the flight has commenced, for example, as a result of a manual data input from the flight crew, then at step 120, the computer 10 commences the input of position data from the aircraft navigation equip- ment. At step 125, the aircraft's position is determined based upon the position data received in step 120. At step 130, the aircraft position is correlated to the map 60 to determine the appropriate map sector member. At step 135, the display is updated to display the sector number result¬ ing from the correlation. At steps 140 and 145, the computer determines the appropriate audio message corresponding to that map sector and causes that message to be output over the aircraft's audio system or network. For example, some newer aircraft are equipped with multi-channel audio systems, which each passenger may access via headphones and a channel selector. One channel of such a network may be assigned to the present system. The audio message unit 50 may be coupled to the network 55 and comprise a plurality of pre-recorded messages, preferably one message for each map sector over which the aircraft will be flying. For example, the message could relate some of the interesting facts regarding the pertinent landmarks or town, such as the population, principal industry, date of incorporation, interesting people who lived there or were born there, etc. As the aircraft passes from one sector to the next, a trigger signal may be provided by the computer, activating the message unit to playback the message for that sector. The message may be repeated continuously until the next sector is reached. At step 150, the computer waits a predetermined time interval, which will typically be dependent upon the size of the map sectors and the aircraft speed. At step 155, tKe routine performs a decision to determine whether the trip is over. This may be the result of a manual data input, or may be an automatic result triggered by coincidence of the aircraft's position with the predetermined destination point. If the trip is not over, the routine loops back to step 120. If the aircraft has reached its destination, the display 40 is updated to show the appropriate sector identi¬ fication for the trip destination and the routine exits. The particular type of display device used to fulfill the function of display 40 is a matter of design choice. In its simplest form the display will be a digital display. Several of the units will be preferably dispersed throughout the aircraft cabin so as to be readily visible to the aircraft passengers. Passengers desiring to utilize the system of the present invention will be issued a map or maps 60, covering OMΠ the area over which the aircraft will be flying during the trip. The map itself need not have the grid printed there¬ on; preferably a transparent overlay will be provided having the grid imprinted thereon. Figure 3 depicts an illustration of a rectangular portion of an overlay such as may be used in the preferred embodiment. The overlay is divided into individually numbered sectors 51...68. Alternatively, of course, a coordinate system may be employed whereby the appropriate map sector is defined by a pair of rectangular coordinates (X,Y) . Referring now to Figure 4 the overlay partially depicted in Figure 3 is placed over the map 60 provided to the passenger, so that the passenger may locate the particu- lar map sector indicated in display 40. For long trips, the map means 60 may comprise a book of maps. The desired degree of resolution of the system will depend to some extent upon the expected flight altitude. With a nominal six mile flight altitude, and with t_Ke assumption that landmarks disposed with the area subtended by a 45° angle from a vertical line extending through the aircraft will be visible to passengers, then a minimum area having a diameter of twelve miles around the vertical line will be visible to passengers. Under these assumptions, rectilinear sectors should have at least twenty-four miles between their boundaries. With good visibility, distant landmarks over 100 miles away may well be visible, allowing use of a sector whose boundaries are at least 200 miles apart. The size of the map sectors is then a matter of design choice. A further advantage of the disclosed system is that it is particularly adapted to control which passengers may utilize the system. The information displayed by display units 40 does not inform the viewer of the location of the aircraft unless the viewer has access to a map and grid overlay. Thus, the system is easily adaptable to produce revenue, for example, by sale of the maps to passengers prior to or during the flight. Similarly, the audio message feature of the system enhances the entertainment value of the audio network headphones which are typically rented to certain passengers. There has been described herein a preferred embodiment of the present invention. Various modifications to the preferred embodiment will be readily apparent to those skilled in the art. For example, a further modification to the system could include a visual message unit, such that a visual message correlated to one or more map sectors could be displayed to the passengers. For example, the movie projector or t.v. system of the commercial aircraft could be adapted to the purpose and operated under control of the computer. The predetermined audio messages could be gen¬ erated by voice synthesis rather than via a recording system. Thus, the scope of the invention should be measured by the claims and the foregoing description. * " ' OMPI

Claims: What is claimed is: 1. System for indicating aircraft position relative to a ground map comprising: aircraft navigation means adapted to generate signals indicative of the aircraft's position; computer means coupled to said navigation means and adapted to generate a display correlation signal indicative of the aircraft's position in relation to a predetermined map of the ground being overflown by the aircraft; and 2. The system of Claim 1 wherein said display means comprises a display adapted to display an indicator for indicating a sector of such map means over which the air¬ craft is flying. 3. The system of Claim 1 wherein said map means includes a grid means for separating areas of the map into predetermined sectors, and said display correlation signal indicates the grid identification of the sector over which the aircraft is flying. 4. The system of Claim 3 wherein said sector on said map has a predetermined sector identifier associated there¬ with and said computer means is adapted to generate said display correlation signal indicative of the sector identi- fier associated with the map sector over which the aircraft is flying. 5. The system of Claim 4 further comprising audio message means for generating predetermined audio messages. 6. The system of Claim 5 wherein said message means is coupled to said computer means, and wherein the particu¬ lar audio message generated is dependent upon the aircraft location. 7. In an aircraft having navigation equipment adapted to generate position signals indicative of the aircraft's position, the improvement comprising the combina¬ tion of: map means of ground area over which the aircraft will be flying; correlating means coupled to such navigation equipment, adapted to correlate such position signals to an area of said map means and generate display correlation signals; and visual display means adapted to provide a visual indication to one or more aircraft passengers of said display correlation signal. 8. The improvement of Claim 7 wherein said map means includes means for separating the indicated ground area into a plurality of map sectors, and said display correlation signal is indicative of one of said predetermined sectors. 9. The improvement of Claim 8 wherein each of said map sectors has a predetermined number associated therewith, and said correlating means and said display means are adapted so that said visual indication comprises one of said predetermined map numbers. 10. The improvement of Claim 8 wherein said correlat¬ ing means comprises computer means including program means, and said computer means is programmed with data indicative of said map sectors. 11. The improvement of Claim 8 wherein said aircraft further has an audio system for audio communication with the aircraft passengers, and said improvement further comprises an audio message unit coupled to said correlating means and said audio system, and said audio message unit is adapted to generate one or more predetermined audio messages for communication to passengers in dependence upon signals from said correlating means. 12. The improvement of Claim 11 wherein said message unit is adapted to generate a predetermined audio message of one or more of said map sectors. 13. The improvement of Claim 12 wherein said prede¬ termined audio message includes information respecting characteristics of one or more landmarks within said sector.

Inventors: THORWALDSON WALDEMAR S, THORWALDSON, WALDEMAR, S.
Applicants: THORWALDSON WALDEMAR S, THORWALDSON, WALDEMAR, S.
Application year: 1984
Main classification: G08G1
IPC codes: B64D47, G01C21