Patent Application
20100201544
The field of the invention is that of flight management systems for aircraft including a system for detecting or preventing collisions with other craft situated in the immediate environment of said aircraft and also comprising a collimated display device that can present symbols to assist in piloting or navigation. These display devices are also known by the term “Head-Up Display” or else “HUD”.
Current civilian aircraft are provided with traffic alert and collision avoidance systems, better known by their acronym “T-CAS”, which stands for “Traffic alert and Collision Avoidance System”. This system is intended to significantly reduce collisions between aircraft. It is mandatory on all craft exceeding a certain weight or transporting a certain number of passengers.
The “T-CAS” systems comprise at least one transponder, means of processing received data and at least one display means. An aircraft transponder is an onboard system which transmits a message concerning the aircraft when it receives an interrogation message. The message generally comprises a code identifying the craft together with more or less detailed information on the position of the craft. In aircraft that are provided with display screens, the “TCAS” function is incorporated in the screen dedicated to navigation, also called Navigation Display or “ND”.
The second region RTA represented by long broken lines represents a region within which another aircraft B can represent a risk of collision. The extreme limit LTA of this region is 3.3 nautical miles in front of the aircraft A, which represents an average flight time of 40 seconds for a jetliner. It has a height HTA of 2400 feet. If an airplane appears within this region and represents a potential danger of collision, a traffic notification is emitted by the device that is called “Traffic Advisory” or else “TA”. Said “TA” informs the pilot that another airplane is located nearby but does not suggest any avoidance manoeuvre. This other craft is called an “intruder”.
The third region RRA represented by solid lines represents a region situated in the immediate environment of the aircraft A. The extreme limit LRA of this region is 2.1 nautical miles from the aircraft A, which represents an average flight time of 25 seconds. It has a height HRA of 1700 feet. In this case, if an airplane appears within this region, the situation is aggravated and the collision appears imminent, an audio message and a visual alert are produced by the device, called “Resolution Advisory” or else “RA”, indicating the aircraft concerned and signaling the action to be carried out by the pilot, namely either to maintain the current trajectory, or to climb, or to descend or else to monitor the vertical speed. This system is designed so that the “TCAS” of the other airplane recommends another manoeuvre. Very often, the “TCAS” indicates to the first airplane that it should climb and to the second airplane that it should descend, which considerably increases the separation between the two craft. When the alert is finished, the system announces the end of the conflict.
When the aircraft has a head-up display, the latter conventionally displays information concerning piloting or navigation. In a head-up display, such information is collimated to infinity and projected by superimposition on the external landscape. An example of this type of figuration is represented in figure 2. The pilot therefore simultaneously sees a projected system of symbols and the “real world” situated outside. In this figure and the subsequent figures, the external rectangle represents the limits of the display field of the display. There is conventionally, on the right of
These days, in civilian aeronautics, there is no head-up display system of symbols to assist in locating another airplane. In the case of “TCAS” alert, the airplane originating the alert is presented on the “ND” screen either by an amber circle for a “TA” (Traffic Advisory) alert, or by a red square for an “RA” (Resolution Advisory) alert. Around this symbol there is displayed, in the same color, the relative altitude of the threatening airplane in relation to the aircraft and the “trend arrow” to the right of the symbol. The “trend arrow” indicates whether the threatening aircraft is climbing, descending or flying level.
The aim of the inventive device is to assist the pilot in locating in the real world the position of a threatening airplane originating a current “TCAS” alarm and to provide the pilot with information on this threat. Such information is essentially the trend, the relative altitude and the relative distance of the threatening craft or “intruder”. For this, a symbol is displayed in the “HUD” that is representative of the “intruder”. This symbol has different representations depending on whether the threatening airplane is within the field of the “HUD”, whether the threatening aircraft is within the field of view of the pilot but outside the field of the “HUD” and, lastly, whether the airplane is outside the field of view of the pilot.
There is also a system called “ASAS”, an acronym which stands for “Airborn Separation Assurance System”, that can be used to guide a succession of craft in landing, take-off or cruising phases, notably for transatlantic crossings where air traffic is very dense. This system makes it possible to significantly reduce the safety distances separating two successive craft while, obviously, retaining the same level of safety. The approach or take-off procedures are thus notably facilitated. The invention can usefully be extended to the case of “ASAS” manoeuvres in order to assist the pilot in displaying the airplane that he is following in the context of such a manoeuvre and monitor its separation distance. In this case, a specific “ASAS” symbol is displayed in the “HUD”.
The inventive system offers numerous benefits. By displaying a system of symbols specific to the “intruder”, the pilot is assisted to locate an airplane originating a “TCAS” alert, and do so in the real world, and, on the other hand, the pilot is provided with certain information on this threat while the changing situation is monitored by direct vision. These days, no assistance is provided to the pilot for locating this type of threat in a system of symbols conforming with the real world and the trend, distance and relative altitude information concerning the threatening airplane is available only on the “ND” screen. This specific system of symbols enables the pilot to acquire an awareness of the situation more rapidly and in more detail than with the current systems, and to monitor by direct vision how the situation originating the “TCAS” alert changes. Time is a critical factor for avoiding a collision in as much as the pilot has only a few tens of seconds to react.
More specifically, the subject of the invention is an air traffic detection system for a first aircraft, said system having detection capabilities in a region situated about said first aircraft, said system comprising at least one head-up display device, said device comprising means of generating, collimating and superimposing symbols on the external landscape intended to assist in the piloting of said first aircraft in the horizontal and vertical planes, characterized in that, when a second aircraft is detected by the air traffic detection system, the display device displays a system of symbols representative of the location of said second aircraft.
Advantageously, in a first application, the system is an anti-collision system of the “TCAS” type, the second craft is situated in a first region where the collision between the first and the second aircraft is possible, the extreme limit of this first region corresponds to a flight time of 40 seconds for the first aircraft and this region has a maximum height of 2400 feet. In this case, there are three possible cases:
Advantageously, in a second application, the system is a system for guiding a succession of aircraft, the first and the second aircraft forming part of this succession. In this case, there are also three possible cases:
The invention will be better understood, and other benefits will become apparent, from reading the following description, given as a nonlimiting example, and from the appended figures in which:
As has been stated, the air traffic detection system according to the invention comprises a head-up display device arranged so that, when a second aircraft is detected by the air traffic detection system, the display device displays a specific system of symbols representative of the location of said second aircraft. The system can be either an anti-collision detection system of “TCAS” type, or a system of “ASAS” type. In both types of systems, there are three distinct cases according to the relative position of the airplane originating the alert in relation to the aircraft which lead to three different symbols. These cases are detailed hereinbelow in the case of a “TCAS” type system and then in the case of an “ASAS” type system.
In the case of a “TCAS” type application, if the threatening aircraft is situated in the field of the “HUD” as illustrated in
In the second case, the threatening airplane is situated outside the field of the “HUD”, but remains within the field of view of the pilot as illustrated in
In the third case illustrated in
Obviously, when the relative position of the two airplanes changes, it is possible to switch from one case to the other during the same alarm. The corresponding symbols can then follow one another.
Similar arrangements are found in the case of “ASAS” manoeuvres, in the case where the carrier receives the instruction from air traffic control to follow another airplane at a fixed distance. A priori, the three symbols described above can be used by replacing the square with a circle in the first two configurations and the tag “RA” with “AS” in the third case, when the aircraft is outside the field of view of the pilot. Because of the nature of the “ASAS” manoeuvre, this third case is improbable, and usually it will the first two cases that apply. As an example,
Here again, these symbols enable the pilot to facilitate the visual acquisition of the airplane to be followed and the implementation of the manoeuvre, for example by placing the speed vector of the carrier on the displayed “ASAS” symbol and monitor the maintaining of his distance throughout the time of the manoeuvre.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07 06466 | Sep 2007 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2008/062139 | 9/12/2008 | WO | 00 | 3/10/2010 |
