DE102009032552A1 - A method of displaying overflown terrain on a display device aboard an aircraft - Google Patents

Abstract

The invention relates to a method for displaying the overflown terrain on a display device on board an aircraft, wherein
- For the terrain points shown, the current probabilities for a collision of the aircraft with these terrain points are calculated and
- The terrain points shown are colored depending on the associated collision probability.

Description

The The invention relates to a method for displaying the overflown Terrain on a suitable display device Board of an aircraft, z. B. on the integrated display of a electronic flight instrument system (EFIS = Electronic Flight Instrument system).

BACKGROUND OF THE INVENTION

at Flights over hilly or mountainous terrain and relatively unknown terrain, coupled with a low altitude above Reason, such. B. in approach or operational mission missions a military transport plane or helicopters and small aircraft with relatively low, absolute summit heights, It can lead to unwanted, threatening approaches of the aircraft come to the site - especially in restricted Visibility.

electronic Flight instrument systems (EFIS) of modern aircraft are equipped with a so-called "Moving Map" for intuitive, timely Visualization of the current geo-referenced position as well the current flight direction of the aircraft over the overflown Terrain equipped.

• a) Darstellung der absoluten, geographischen Höhen – analog der Farbgebung einer topographischen Karte.
• b) Darstellung der Geländehöhe in Relation zur momentanen Flughöhe des Luftfahrzeugs (dynamisch veränderlich) oder in Relation zur absoluten Gipfelhöhe des Luftfahrzeugs (statisch unveränderlich). Diese Form der Darstellung ist unter dem Begriff der höhenkodierten Farbgebung des Geländes bekannt.

The known forms of visualization of the terrain on a "moving map" are currently limited to the following two basic approaches:

• a) Representation of the absolute, geographical heights - analogous to the coloring of a topographical map.
• b) Representation of the terrain altitude in relation to the current altitude of the aircraft (dynamically variable) or in relation to the absolute altitude of the aircraft (static immutable). This form of representation is known by the concept of height-coded color of the terrain.

Of the Advantage of the form of representation b) compared to that of a) justified in the fact that by the height-coded Coloring the site an additional warning functionality is implemented. The threat to the aircraft classified areas of the terrain can in this form of Representation z. B. in reddish or orange shades be specially highlighted to generate a visual warning.

However, the disadvantage of the form of representation b) is due to the relative simplicity of this warning functionality. This leads to a possibly poor differentiation with respect to the actual threat to the terrain for the aircraft. An illustrative example of this is in 1 shown. Those terrain areas with the most striking coloring 101 - (usually, this will be a bright red or orange) - following the underlying logic of the ad, by definition, the biggest threat to the aircraft 102 According to the indicated flight path sector 103 the plane is flying in 1 but not at all on these most critical terrain areas 101 at least not right now. The real threat is in 1 obviously from the comparatively low mountain ridges of the ever-narrowing valley basin, into which the aircraft 102 straight into it, not from the higher peaks 101 at the horizon.

Yet the disadvantage of the simple, height-coded is clearer Coloring, if classified as critical areas of the terrain with her red or orange warning behind the aircraft lie - in areas thus, of which the aircraft currently removed or not approaching.

Of the The invention is therefore based on the object, a color terrain representation to generate the actual threat of the Terrain for the aircraft can be displayed.

These Task is solved by the method according to claim 1. Advantageous embodiments of the invention and a device which implements and displays this method are Subject of further claims.

SUMMARY OF THE INVENTION

A well-known form of presentation for the visualization of the terrain on a "moving map" is the so-called height-coded Color of the terrain. In this form of presentation is the terrain height in relation to the current altitude of the aircraft (dynamically changeable) or in relation to the absolute height of the aircraft (static immutable) Highlighted in color. This implements the height-coded Coloring the terrain a simple warning functionality, which warns against all higher terrain surveys - independent of flight direction, attitude, speed, distance and more relevant characteristics. This simple warning functionality is extended according to the invention so that the actual Threat to the terrain for the aircraft Display is brought.

This will determine the real threat to the terrain of the aircraft by calculating the likelihood that the aircraft will collide with that terrain point for each point of the terrain represented. The The terrain profile shown is colored or highlighted in color as a function of this collision probability (the term "color" in this context also includes gradations or color gradients of gray tones). The calculated collision probability is transformed into a corresponding warning color spectrum (eg from green or blue for little or no collision probability to red or orange for the highest danger level).

• – Parameterklasse 1: geometrische Geländeparameter – hierzu zählen:
• – der relative Ortsunterschied des Luftfahrzeugs zu Geländeerhebungen nach Distanz und Höhe
• – weitere Parameter zur ortsabhängigen Beschreibung des Geländes in Relation zum Luftfahrzeug
• – Parameterklasse 2: physikalisch/flugdynamische Kenngrößen des Luftfahrzeugs – hierzu zählen:
• – die momentanen Werte für Fluggeschwindigkeit, Beschleunigung, Drehraten
• – die Fluglage (Rollwinkel, Nickwinkel, Gierwinkel)
• – die absolute Gipfelhöhe des Luftfahrzeugs
• – Flugleistungsdaten des Luftfahrzeugs (wie z. B. maximales Steig- und Sinkvermögen)
• – weitere Parameter, die die Flugdynamik des Luftfahrzeugs beeinflussen (z. B. die Konfiguration von Landeklappen und Fahrwerk etc.).

The collision probability is calculated as a function of two classes of parameters:

• - Parameter class 1: geometric terrain parameters - these include:
• - The relative difference in the location of the aircraft to terrain surveys by distance and altitude
• - Further parameters for the location-dependent description of the terrain in relation to the aircraft
• - Parameter class 2: physical / flight dynamic characteristics of the aircraft - these include:
• - the current values for airspeed, acceleration, yaw rates
• The attitude (roll angle, pitch angle, yaw angle)
• - the absolute maximum height of the aircraft
• - Flight performance data of the aircraft (such as maximum climbing and sinking capacity)
• - other parameters that affect the flight dynamics of the aircraft (eg the configuration of flaps and landing gear etc.).

About that In addition, other influencing factors, z. B. from meteorology (wind direction and strength) and Values from an air path prediction (eg from a ground Collision Avoidance System (GCAS)) for the calculation of Collision probability are taken into account.

By Consideration of all these parameters results in a much more differentiated and more precise Image of the real, actual threat to the terrain for the aircraft. This image of the actual Threat is - in the sense of the invention - as interpreted the current threat potential of the terrain. This threat potential can, for. B. in the EFIS representation of a "Moving Map ", to be displayed - d. H. it will analogous to a weather radar implemented a kind of "threat radar", that is capable of real the threat of the terrain visualize for the aircraft. Thus, the well-known "Moving Map "into an intelligent" Moving Threat Map "transferred.

Of the Advantage of the invention is that targeted only those Terrain areas with the critical warning colors (eg red or orange) representing the aircraft actually pose a correspondingly serious threat and that, on the other hand, those terrain areas of which no immediate threat, never in bright warning colors to shine. Thus, the pilot in the assessment of current situation better supported or relieved and this can help the flight safety - in particular on critical missions or landing approaches - too increase.

The inventive representation is not on the classic 2-dimensional map display (plane projection) of a "Moving Map "limited. She may as well be on one spatial or perspective representation of the terrain transmitted on a so-called "Synthetic Vision Display" become. In the corresponding 3-dimensional terrain representation of the "Synthetic Vision Display" will then too the actual threat to the site for that Aircraft based on the corresponding distribution of the warning color spectrum be intuitively readable.

BRIEF DESCRIPTION OF THE FIGURES

The The invention will be described in more detail below with reference to figures explained.

• – 101: höchste Geländeerhebungen
• – 102: momentane Position des Luftfahrzeugs
• – 103: auf Basis der momentanen Fluglage vorausberechneter Flugpfad des Luftfahrzeugs

1 shows the so-called "Tactical Terrain Awareness Display" of the Airbus A400M. Symbolize here:

• - 101 : highest terrain elevations
• - 102 : current position of the aircraft
• - 103 : on the basis of the current attitude precalculated flight path of the aircraft

• – 201: höchste Geländeerhebungen
• – 202–104: stufenweise niedrigere Geländeerhebungen
• – 205: momentaner Steuerkurs
• – 206: momentane Position des Luftfahrzeugs

2 shows a schematic representation of a "moving map" with height-coded color of the terrain according to the prior art.

• - 201 : highest terrain elevations
• - 202 - 104 : gradually lower terrain elevations
• - 205 : current heading
• - 206 : current position of the aircraft

• – 301: auf Basis der momentanen Fluglage vorausberechneter Flugpfad des Luftfahrzeugs

3 shows one too 2 analogue representation with a flight path prediction and height-coded color scheme of the terrain

• - 301 : on the basis of the current attitude precalculated flight path of the aircraft

• – 401: hohe Geländeformation in relativ großer Entfernung
• – 402: mittelhohe Geländeformation in mittlerer Entfernung
• – 403: niedrige Geländeformation in relativ geringer Entfernung
• – 404: Flugrichtungsvektor des anfliegenden Luftfahrzeugs

4 shows an example of an approach scenario to different high and different distant terrain formations:

• - 401 : high terrain formation at a relatively long distance
• - 402 : mid-high terrain formation in the middle distance
• - 403 : low terrain formation at a relatively short distance
• - 404 : Flying direction vector of approaching aircraft

• – 501: Ort des Luftfahrzeugs und seine momentane Bewegungsrichtung v →
• – 502: Elevation des Geländes am Ort r → ₁
• – 503: Elevation des Geländes am Ort r → ₂

5 schematically shows individual terrain points with different high threat potential for an approaching aircraft:

• - 501 : Location of the aircraft and its current direction of motion v →
• - 502 : Elevation of the terrain at location r → ₁
• - 503 : Elevation of the terrain at location r → ₂

• – 601: Geländebereich mit dem größten Bedrohungspotential für das Lfz.
• – 602–604: stufenweise geringeres Bedrohungspotential für das Lfz.

6 shows a first example of a terrain representation according to the invention:

• - 601 : Terrain area with the greatest threat potential for the Lfz.
• - 602 - 604 : gradual lower threat potential for the Lfz.

• – 701: Geländebereich mit dem größten Bedrohungspotential für das Lfz.
• – 702–703: stufenweise geringeres Bedrohungspotential für das Lfz.

7 shows a second example of a terrain representation according to the invention:

• - 701 : Terrain area with the greatest threat potential for the Lfz.
• - 702 - 703 : gradual lower threat potential for the Lfz.

DESCRIPTION OF THE INVENTION IN DETAIL

In 2 is a schematic representation of a "Moving Map" with height-coded coloring according to the prior art shown. Following the simple logic of the height-coded color scheme, in this form of presentation, the highest terrain elevations 201 especially stressed. This is independent of the direction of flight, attitude, speed, distance and other relevant characteristics of the aircraft. In 2 can be seen that the displayed current heading 205 the aircraft is not directly on the highest terrain surveys 201 supplies. Whether the aircraft can safely follow this heading, or perhaps not the lower terrain surveys 202 . 203 respectively. 204 At the end of the valley, in which the aircraft flies into, already lead to a critical flight situation, remains in the form of representation of 2 in principle unanswered.

The disadvantage of the warning function of a pure height - coded "Moving Map" coloring is in 3 even clearer. The scenery of 3 is with the of 2 identical. Due to the flight path prediction 301 It can be seen that the aircraft does not fly tangentially straight ahead, but is currently in a left turn. The aircraft is therefore removed from the highest terrain surveys in the upper part of the display. However, this does not affect the warning color representation of the height-coded coloring of the "moving map", according to the state of the art - a possible risk of collision by the ridges of the left valley flank to which the aircraft is moving remains unconsidered.

The real threat to the terrain for an aircraft does not necessarily derive from the highest terrain elevations. It is easy to find situations in which even relatively low terrain structures in close proximity to the aircraft are much more critical than larger surveys that are farther away (cf. 4 ), This circumstance can be explained by the respective necessary acceleration, which - starting from the momentary state - has to act in a vertical direction on the aircraft in order to be able to fly over the terrain survey. 5 illustrates this relationship: For the overflight of the place r → ₁ , a larger vertical acceleration a _z = c _{1 is} necessary, as for overflight of the place r → ₂ , although r → _{2 has} a greater elevation than r → ₁ . The fact that c ₁ > c ₂ is, can be seen trivially from the curvature of the respective overflight trajectory.

To describe the actual threat of the aircraft, the concept of threat potential f _T mentioned above is introduced. This is understood here as the sum of all available information which unambiguously assigns a collision probability P _{C of} the aircraft with this terrain point to each location (φ _LAT , λ _LON , h _ALT ) in the terrain.

Δh:

rel. Höhendifferenz zw. dem Lfz. und dem Ort (φ_LAT, λ_LON, h_ALT)

Δd:

euklidische Distanz zw. dem Lfz. und dem Ort (φ_LAT, λ_LON, h_ALT)

v → AV:

Geschwindigkeitsvektor des Lfz.

a → _AV:

Beschleunigungsvektor des Lfz.

(Ψ, ϑ, φ)_AV:

Flugrichtung und -lage des Lfz.

The threat potential f _T can be understood as a functional mapping of the space I of the geometric terrain parameters as well as the physical / flight dynamic aircraft characteristics to the right open unit interval [0, 1) ε R: f _T : I → [0, 1), f _T (Δh, Δd, v → _AV , a → _AV , ψ _AV , θ _AV , φ _AV , ...) = P _C (φ _LAT , λ _LON , h _OLD ) (1) With

.delta.h:

rel. Height difference betwee the Lfz. And the place (φ _LAT , λ _LON , h _ALT )

.DELTA.d:

Euclidean distance between the vehicle and the place (φ _LAT , λ _LON , h _ALT )

v → AV:

Speed vector of the lfz.

a → _AV :

Acceleration vector of the Lfz.

(Ψ, θ, φ) _AV :

Flight direction and position of the Lfz.

• • absolute Gipfelhöhe des Luftfahrzeugs
• • Flugleistungsdaten des Luftfahrzeugs (wie Steig- und Sinkvermögen etc.)
• • weitere Parameter, welche die Flugdynamik des Luftfahrzeugs beeinflussen (z. B. die Konfiguration von Landeklappen und Fahrwerk etc.).
• • meteorologische Daten (wie Windrichtung und -stärke)
• • Kenngrößen einer Flugpfadprädiktion
• • flugdynamische Optimierungen wie z. B. die Ausnutzung eines momentanen Geschwindigkeitsüberschusses des Luftfahrzeugs bei der Berechnung einer anteiligen Umwandlung von kinetischer Energie in eine Flughöhenreserve (potentielle Energie).

The threat potential f _T describes the influence of geometric as well as physical / flight-dynamic boundary conditions between aircraft and terrain in the determination of a collision probability. of the terrain point (φ _LAT , λ _LON , h _ALT ). Here, in definition (1) -according to a concrete realization for the calculation of the threat potential f _T -the consideration of further parameters and characteristics is easy possible, such. B .:

• • absolute peak height of the aircraft
• • flight performance data of the aircraft (such as climbing and sinking capacity, etc.)
• • other parameters that influence the flight dynamics of the aircraft (eg the configuration of flaps and landing gear, etc.).
• • meteorological data (such as wind direction and strength)
• • Characteristics of a flight path prediction
• • flight dynamics optimization such. For example, taking advantage of a momentary overspeed of the aircraft in calculating a proportionate conversion of kinetic energy into a flight reserve (potential energy).

From definition (1), there is obtained at each instant t actual probability P _C for the collision of the aircraft with any location (φ _LAT , λ _LON , h _ALT ) of the overflown terrain.

A mathematically constructed threat potential in this manner is directly proportional to the effects and consequences of approaching the aircraft to a given terrain structure. The greater the threat potential f _T , the greater are the resulting consequences for the aircraft - at the end of which there is a potential collision with the terrain.

In the example scenario of 5 the location r → _{1 has} a greater collision probability P _C for the aircraft than the location r → ₂ , ie P _C (r → ₁ )> P _C (r → ₂ ).

The threat potential f _T from Definition (1) can be calculated on the basis of its mathematical construction over any digital elevation model of the overflown terrain.

• • US 5 555 175 A
• • DE 197 09 097 A1
• • US 2007/0055418 A1
• • EP 1 369 665 A2 .

Depending on the parameters and parameters available in a certain aircraft type, numerical methods which can be used to calculate a threat potential f _T according to definition (1) are known to the person skilled in the art. This applies in particular to the following publications:

• • US 5 555 175 A
• • DE 197 09 097 A1
• • US 2007/0055418 A1
• • EP 1 369 665 A2 ,

A combination of the above-mentioned methods is also conceivable for a concrete calculation of the threat potential f _T according to definition (1).

In accordance with the present invention, the warning functionality of a "moving map" representation is aligned with the actual threat to the aircraft from the terrain. The actual threat posed by the threat potential f _{T is} mathematically unambiguously described. By f _T it is possible to assign a criticality to each location (φ _LAT , λ _LON , h _ALT ) of the illustrated terrain, which indicates the instantaneous probability P _C for the aircraft to collide with precisely that location. Through this property of f _T it is possible in the map presentation of the "Moving Map" to create a situational awareness of specific threats to the pilot. This fact differentiates the present invention substantially from known so-called. "Ground collision avoidance systems", which usually only calculate a single alternate trajectory for the aircraft - which almost always ends with the acoustic warning command: "pull up". However, if the pilot according to the invention has a situation-dependent awareness of the actual threat to each point of the surrounding terrain, it is z. For example, it is possible to avoid dangerous pull-up situations by making predictive changes to the course.

In practical terms - in the extreme case never attainable according to definition (1) - a collision can only occur with those terrain points for which a collision probability of P _C = 1 results. All other areas of the terrain necessarily have a lower collision probability of P _C <1. Due to the current position and attitude of the aircraft, there are always larger terrain areas for which it is physically impossible to collide with the aircraft (P _C = 0). The latter is especially true for terrain areas which z. B. far behind the aircraft, in the opposite direction of flight, are.

According to the invention, the instantaneous collision probability P _C calculated for each location (φ _LAT , λ _LON , h _ALT ) of the terrain is transformed into a warning color spectrum by means of f _T. Subsequently, the corresponding terrain representation of the "moving map" is colored with the color distribution resulting from P _C. In this case, the warning color spectrum W _c is constructed such that each collision probability P _{C is} uniquely assigned a corresponding warning color c ε W _c : f _c : [0, 1) → W _c ; P _C (φ _LAT , λ _LON , h _ALT ) ↦ f _c (P _C (φ _LAT , λ _LON , h _ALT )) = c (2)

The color distribution over all terrain points (φ _LAT , λ _LON , h _ALT ) of the "Moving Map" resulting from Definition (2) thus corresponds to the actual instantaneous threat to this terrain for the aircraft at time t. The color distribution is a clear image of the threat potential f _T.

The concrete choice of a suitable warning color spectrum W _c for visualizing the actual threat to the terrain for the aircraft depends, on the one hand, on the HW properties of the "moving map" used and, on the other hand, on the requirements for the man-machine interface (HMI) used. It is advantageous - analogous to the previously used color representations - those terrain areas of which currently the biggest threat emanates to color with corresponding red or orange shades. It would also be permissible in this case for a common warning color c ε W _c to be assigned to a plurality of approximately equal collision probabilities, ie that the warning color spectrum used can not necessarily be continuous, but also discrete. Analogously, this applies to a discrete calculation of P _C as a function of the spatial resolution of the underlying digital terrain model (terrain elevation database). It should be noted that the specific choice of the used warning color spectrum W _c and a continuous or discrete calculation of the location-dependent collision probabilities P _C for the basic concept of the invention are irrelevant, but merely represent various advantageous embodiments.

In 6 an example of the terrain representation according to the invention in map form is shown schematically. It is the same situation as in 2 , Those terrain areas that presently have the greatest collision probability for the aircraft are colored (typically in shades of red or orange) in corresponding warning colors 601 (relatively high probability) or 602 and 603 (for gradually slightly lower collision probabilities). These are, in the case of 6 , the ridges at the end of the basin on which the aircraft is currently flying. By contrast, the much higher terrain elevations in the upper area of the map (cf. 2 ) are colored with a color of lower criticality because they presently represent a much smaller threat to the aircraft due to their distance.

6 makes it clear that the attention of the pilot is directed to the currently critical terrain areas by the representation of the invention. In particular, it is not distracted by the display / marking of terrain areas which, although having a greater absolute height, are of subordinate importance for the current flight situation.

Another example of the map display according to the invention shows 7 , It is the same situation as in 3 , With the most critical warning color 701 only the highest crests of the ridge on the left edge of the basin on which the aircraft turns are dyed. With gradual less critical color coding 702 . 703 a large part of the left basin edge is colored according to the prediction of the flight path. This color scheme according to the invention is intended to warn the pilot of the actually threatening terrain areas depending on the situation.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 5555175A [0035]
• - DE 19709097 A1 [0035]
• US 2007/0055418 A1 [0035]
• - EP 1369665 A2 [0035]

Claims (7)

A method for displaying the overflown terrain on a display device on board an aircraft, characterized in that - for the terrain points shown each time the current probabilities for a collision of the aircraft are calculated with these terrain points, and - colorized the terrain points shown in dependence on the associated collision probability become. Method according to claim 1, characterized in that that the collision probability on the basis of geometric Terrain parameters as well as physical / flight dynamic characteristics of the Aircraft. Method according to claim 2, characterized in that that for the calculation of the collision probability additionally takes into account the current meteorological conditions become. Method according to claim 2 or 3, characterized that for the calculation of the collision probability In addition, the characteristics of an air path prediction be taken into account. Method according to one of the preceding claims, characterized in that the terrain representation in Card form takes place. Method according to one of the preceding claims, characterized in that the terrain representation in a spatial-perspective representation takes place. Device for terrain display, on the method according to any one of the preceding claims is implemented.

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