CN1105954C - Route planning, terrain evading and fly environment warming system for general-purpose aviation - Google Patents
Route planning, terrain evading and fly environment warming system for general-purpose aviation Download PDFInfo
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Abstract
The present invention provides an environment alertness system used for route planning, terrain avoidance and ballooning of general aviation. A set of terrain nodes with the height exceeding the smallest flying height are positioned and aggregated. Calculation methods developed by the present invention such as collision examination, a mountain area boundary and region growing technique, etc. are fundamental operation on the basis of a terrain model. Dynamic routing selection is carried out by a visibility figure method, which is matched to reduce requirements to immediate calculation. In the method, space of search, etc. is reduced by establishing a partial visibility figure of the terrain and eliminating terrain fine details which does not influence flight path selection, which is irrelevant to the navigation space. A serial of CFIT alarm functions using terrain information as reference can effectively apply the existing airborne terrain information source by multiplex and variable analyticity characteristic of an octant-tree terrain model.
Description
Down the unexpected storms of barrier is relevant with flying into being reduced in control in the broadest sense in the present invention, in particular, and with the topographic(al) data processing and the algorithm of the unexpected landform vigilance of barrier and warning system are relevant with flying under control.
Under control with flying into barrier (Controlled Flight into Terrain CFIT) warns employed data to be provided by flight management computer, GPS (GPS) receiver and other airborne equipment.The CFIT of known technology warning is the flight path of the curve-cooperation outside forecast three-dimensional of the proximal most position that receives according to aircraft and speed data.Then relatively, and the assessment of the potential threat that bumps of calculating aircraft and landform with the internally shape high-level diagram of the flight path of this prediction and adjacent domain.The system of the above-mentioned type can watch forward 120 seconds approximately.Here it is so-called " accessible time " with respect to the warning of " how long colliding in addition ", and just " terrain-avoidance " is with respect to " landform vigilance ".
The airline of the U.S. is devoted to reduce the CFIT unexpected storms can date back to nineteen forty-seven.The radio altimeter data is used near warning system (GPWS) in the standard ground of known technology, if the landform headroom deficiency of aircraft promptly can provide audible warning sound.If fly into precipitous landform, promptly can warn the situation of delay, because the GPWS of standard is the landform that rises by the radio altimeter detecting of overlooking.
Allied Signal company provides the GPWS-EGPWS of " reinforcement " type, and SextantAvionique company " the collision on the ground avoidance system " that provide (GCAS) can draw landform around the flight path on cockpit display, and early warning is provided.These two kinds of systems set up around the dimensional topography data, and implement real forward sight predictive ability according to the climbing performance of aircraft.Its technology is divided into three parts; The appearance of GPS and other high precision navigational system provides accurate localization and upgrades with very short time; The use higher speed reaches the computing technique than large memories; And accurate, complicated global topographic(al) data storehouse, comprise global digital terrain height data bank (DTED).Fig. 1 shows the GPWX system skeleton diagram of DASSAULT ELECTRONIQUE GCAS.
In EGPWS and GCAS, the topographic(al) data storehouse is the core of system.The forward sight algorithm compares with the following projected position of this data bank and aircraft, and gives a warning according to this.Use DTED can make system show near the landform that aircraft is.During the flight, can show the mountain peak and the landform of aircraft below among the DTED, so that the pilot to be provided the vigilance to the flight environment.A lot of forward sight warnings are such as flight profile, mission profile that conflicts with landform or flight path early warning in advance.In the mountain area during emergency descent, or the change flight path to be when avoiding poor weather, and the forward sight warning helps more to prevent that any situation from causing CFIT.
But, the topographic(al) data storehouse has occupied the storage space of huge amount.If take advantage of in 10000 kilometers the zone at 10000 kilometers and to draw the landform high-level diagram, just needs 10 with the spacing of every hectometer
10Individual net point.Clearly, owing to want consecutive access 10
10The calculating of individual net point is very huge, therefore needs to reduce or compress these information.In addition, utilize landform can also do a lot of navigation features, such as the flight program that can do the best, or according to instant flight environment emergency change path, when the complexity of algorithm increased, these all were limited by the quantity of DAQ and the cost of calculating.No longer via further processing or by the real material of the landform of other form, such as feature or vector representation, DTED also can't give the geometric relationship between the data element.
Purpose of the present invention promptly is path planning, terrain-avoidance and the flight environment vigilance system that is provided for General Aviation at the deficiencies in the prior art.
In a lot of application facet, particularly flight management, the necessary whole DTED data bank of access is with the destination of decision or change flight.In this description and the warning of landform vigilance, and the problem relevant with navigation safety, be to carry out in the landform navigation space of coding.The coding of the net point archives of digital terrain height data (DTED) is four fens trees of formula (quad-tree) representation of deriving according to the representation space data structure.Each element in the DTED archives all is encoded into the Morton numbered sequence about its position in the net point archives, the height data of division (scaled elevation data) and to contain equivalent (equal altitudes) scope be its characteristics.Under this kind data structure, DTED can be configured to the integer of ascending chain on a group.Each integer is represented a node, and the planimetric position in the node, the height of division and the scope interleaved code of containing become one group of bit position to constitute an integer.The ordered series of numbers of coding is defined by octa-tree (Oct-tree) model of landform.Navigation feature not only for the height data with reference to the landform octa-tree, also carry out thereon simultaneously and handle and computing, so far navigation space is transformed into its coding integer ordered series of numbers from the DTED array.
On based on the navigation space of landform octa-tree, can carry out several navigation features.Below represent a kind of preferred embodiment with flying height definition dynamic risk district band.In preferred embodiment, make minimum flying height top one group of Terrain Elevation node the position and assemble these positions.The algorithm such as collision detection, border, mountain area and region growth technique that the present invention developed is the fundamental operation on these relief blocks.In another kind of preferred embodiment, adopt visibility chart method (visibilitygraph approach) to do dynamic route and select, to reduce needs to instant calculating.The part visibility chart that the method mat is set up landform to be dwindling search space, and gets rid of and do not influence the topographic details of selecting flight path, and the size of the size of landform and navigation space has nothing to do.
In case can determine the physical features in aircraft flight path and landform zone at an easy rate, several CFIT warning functions that are used for aircraft navigation also become and are easy to carry out.In addition, its meaning contains the data bank that in order to carry out geometrical calculation access has the Terrain Elevation data.Via the characteristic of the multiple and variable resolution degree that utilizes the octa-tree relief block, use topographic(al) data can implement at an easy rate as a series of CFIT warning functions of reference.Its function comprises that warning, barrier prompting, landform shield, landform fluoroscopic image, passive ranging, instant routing and path planning are approached in ground, meteorological demonstration covers folded and destination covers folded.
The paths planning method of known technology is to use predefined barrier model.In addition, the quantity of the data of acquisition DTED and the cost of calculating all are negative factors.In the present invention, during carrying out flight planning, the explosive area band dynamically changes.In addition, use one deck octa-tree landform, make on the line arithmetic capability more as abundant.
From the following detailed description and conjunction with figs., can understand objects and advantages of the present invention.
Fig. 1 shows system's skeleton diagram of the GPWS of known technology.
The bit interleaved code of Fig. 2 display position sign indicating number and 2-D, 3-D projection.
Fig. 3 shows the example of the navigation space of dangerous node.
Fig. 4 shows explosive area band possible in the relevant heading.
Fig. 5 is presented at (the explosive area band is with reference to figure 3) between band expansion area, explosive area, uses the dichotomy search decision boundary node of dangerous node ordered series of numbers.
Fig. 6 is presented in conjunction with boundary types and destination position.
Fig. 7 shows explosive area band expansion and derives destination.
Fig. 8 shows the explosive area band with respect to different starting points and point of destination.
Fig. 9 display visibility figure and its tree structure.
Figure 10 shows the embodiment example of instant flight path planning.
Figure 11 shows the example of the embodiment of obstacle avoidance.
Figure 12 shows the example of the embodiment that produces the landform fluoroscopic image.
Preferred embodiment describes in detail
1, relief block
In the field of image processing, mat is pulled over array, and ground is inferior to be divided into many four minutes quadrants, and tree can be represented 2 dimensional region (2 in four minutes
n* 2
nThe form of binary bit array).If this four fens quadrants are to be mixed by 1s or 0s, it can be further time be divided into many four minutes quadrants, till this process repeats to four fens quadrant always and only constitutes (being called as leaf node) by 1s or 0s.In fact, the big zone of 1s (or 0s) is to be represented by the node of single four minutes quadrants or tree structure.Similarly, three-dimensional object can represent 2 by octa-tree
n* 2
n* 2
nArray can inferior be divided into eight fens quadrants (octant).If the element in eight fens quadrants is all identical, this octa-tree finishes; Otherwise further produce eight fens quadrants of 8 following one decks again, with eight fens quadrants of detailed representation more.
In preferred embodiment of the present invention, adopt the octa-tree structure of another kind of form.Add the 4th parameter S, to represent the size of leaf node.By its three-dimensional coordinate and the information of size, the zone, ground on the face of land can be represented with the position code of a 3-D.With the peak dot on the face of land (I, J, the K) method of the position code of mapping to a node, (I, J K) become 16 carry value to constitute with S bit interleaved code by element.Therefore, on each position, the S bit before the K bit, the K bit before J bit gas and the J bit before the I bit.(I, J, K) with the S interleaved code after, position code be set of number (0,1,2,3,4,5,6,7,8, C) one of them.The size of node information of number of times representative that numeral " 8 " or " C " occurs in the position code through merging.
In the example of Fig. 2, the 4th of node
N-1The combination of individual bit (being the combination of the 1st bit of each numeral) equals the binary representation method of I value.Be respectively the (4
N-1+ 1) individual bit repeats this kind and is combined into J, and the (4
N-1+ 2) individual bit becomes K, and the (4
N-1+ 3) individual bit constitutes the value S of size, wherein n (n=1,2 ...) be the resolution parameter.Though 4 components of node (be I, J, K, fully independent between S), they are with a monodrome representative.Coding and decoding processing all can be used n ary operation execution by turn under the design that this bit interlocks.
Employed addressing design is the Morton numbered sequence in the landform octa-tree, and it also is to utilize aforesaid bit interleaved code to constitute.To the I of 3-D position code, the J bit is carried out the position code that the modulo-4 computing can obtain 2-D, wherein the K bit is designated as 0, and the reservation of S bit does not change.In Fig. 2, node＜00001473 〉
16Projection on the IJ plane is＜00001033 〉
16To node＜0000148C〉through merging
16, the projection sign indicating number is＜00001088 〉
16
2, the modelling of navigation space
Generally speaking, present path planning method is to be made of two stages.In the phase one, produce the search space that constitutes by all possible paths, they all avoid the obstacle between starting point and point of destination.In case produce search space, subordinate phase is to seek a path of satisfying the specific limited condition.On the typical case, it is static that these methods are based on navigation space (obstacle, landform and threat), and is the hypothesis of knowing fully in advance.
The flight path plan calculus method of a lot of known technologies is the knowledge of utilizing " cost " in path in the navigation space, obtains optimal path through some the objective function minimization that makes definition path " cost ".These algorithms are deriving of " shortest route problem ".Common strategy is that the pre-service search space is to reduce the cost of instant calculating.Pretreated method can be divided into two classes, and the one, organize search space figure according to Terrain Elevation, another kind is that precalculated value at cost is embedded among the figure of search space.Flight path plan calculus method described in the invention is according to the restriction that flying height, flying distance is reached the time of destination in addition.Though aircraft has been clear the navigation space during the task, barrier can change along with the restrictive condition of operation, therefore wants to realize immediately between must in office.
Flight path plan calculus method described in the present invention is to carry out on the quadrant structure in eight minutes in the landform of representing navigation space, and does not use any other data formats to represent terrain feature (linearity or polygon feature).Because the shape of obstacle is along with highly dynamically changing, therefore representing obstacle with the polygon of static state and be not suitable for instant dynamic flight path planning.The landform octa-tree is organized into linear ordered series of numbers, and wherein each element is represented a leaf node of tree structure.Each node is with a single integer representation, and the equivalent element set of expression net point archives.Use octa-tree to simplify the operation of acquisition barrier from the topographic(al) data storehouse.
The octa-tree relief block comprises the information of 2-dimension (2-D) and 3-dimension (3-D).Direct one to one projection between corresponding node in the four Fen Shu spaces that but tree-shaped Methods for Coding allows 2-D and the 3-D octa-tree space.This allows to calculate the flight path of 3-D in four Fen Shu spaces, significantly simplified evaluation work.Work such as use the 2-D representation also to simplify to change between the route segment of position such as abutment points, decision point-to-point transmission and how much coordinates and node address.
3. core path plan calculus method
3.1 the acquisition of barrier
3.1.1 realize barrier
In the landform octa-tree, dividing the node of height value more than flying height is so-called " dangerous node ", and it is just dangerous that this meaning aircraft enters the landform zone that is occupied by these nodes.Dangerous node ordered series of numbers is the subclass of four fens trees, the node of expression navigation space.But, dangerous node ordered series of numbers does not provide any clear and definite physical features information (for example connectivity or boundary condition) in the navigation space.In Fig. 3, show in the hazardous location to comprise 26 nodes be organized into a collating sequence, but whether node 1 or node 26 belong to identical join domain and uncertain.In addition, even if dangerous node is arrived whole navigation space by " distribution ", also have only a few dangerous node can make the flight path of appointment be on the brink of dangerous situation.For example, in Fig. 4, the hazardous location of 5 connections is arranged, but for the path that will arrive purpose 1, possible barrier is only limited to regional A to C.
The dangerous node relevant with present direction is called obstacle nodes, and is organized into one group of position code, and it represents the scope that the explosive area band is contained in the aircraft navigation space.The step of tissue disorder's thing is as follows:
(1) from the landform octa-tree, captures dangerous node ordered series of numbers according to the height threshold value.With suitable vertical division factor K landform is organized into district's band or aspect, for example district's band of 20 meters.Inspect each node of octa-tree, see if there is K value (being embedded in the position code) and surpass threshold value.The K value is less than disregarding that the threshold value person omits.Resulting ordered series of numbers comprises that all have the node of potential danger in the navigation space.
(2) use " producing and test " strategy, mat obtains barrier node ordered series of numbers to the collision detection (or detecting point of crossing) of direct-path between the starting point (S) that is positioned at appointment and point of destination (G).Direct-path is the straight line between a S and G, the octa-tree node of decision on the straight line between a S and G.Each point on the line from the S point, contrasts the inspection of dangerous leaf node ordered series of numbers.If the point on the line and any dangerous node matching, then the search space leaf node is deposited in the ordered series of numbers, for subsequent expansion explosive area band.Sometimes, the point on the direct-path has that to surpass more than one component crossing with identical barrier node.
(3) increase the explosive area band that connects, to make regional summit as destination.Explosive area band extension process comprises seeks the barrier leaf node that is adjacent to the leaf node that will be expanded.The fundamental purpose of this extension process is for obtaining one group of destination corresponding to the explosive area band in navigation space; Then use these destinations as possible flight path, depart from avoiding and collide with landform.
3.1.2 the expansion of explosive area band
The position code of 4 main directions of calculating its adjacency is with expansion barrier leaf node.This computing is to carry out with pulling over, arrives boundary node always, and boundary node is without any the node of adjacent node in dangerous leaf node ordered series of numbers.The size of adjacent node is with at present the size of node of " expanding " may be different, and wherein 2
dTake advantage of 2
dSize of node be 2
d, and the level of node is defined as d.For etc. the adjacent node of size search dangerous node ordered series of numbers.If the adjacent node of size such as in ordered series of numbers, find, then repeat this action and search bigger adjacent node, and repeat up to finding adjacent node, or tree structure arrives the level in abutting connection with root.
If, promptly show the adjacent nodes that perhaps exist some sizes less, or this node is a boundary node through not finding adjacent node yet after this processing.If this node does not come across in the node ordered series of numbers, it may be contained in the node that the upper strata merged.Node with the projection sign indicating number that uses in the last relatively loop of two fens searching procedures is contained the node of being inquired about, or the node of being inquired about is contained.Whether but mat is found this feature, have four fens quadrants of the identical adjacent node of any size to exist with decision.Be used at last the relatively position code of loop if the adjacent node of the node in the test is contained, just need further search, otherwise present expanding node be the border.For example, the extension process of the node 21 among Fig. 3 runs into the border in " south ", in north and east asynthesis thing node, and need further handle one deck down in " west ", as shown in Figure 5.
Use corresponds respectively to the boundary types coding of 1,2,4 and 8 pairs of barriers of interpolation sign indicating number of northern side, east side, west side, southern side.Zero shows that this node is on the border without any a side.The position that shows explosive area band and possible destination as Fig. 6.For example, the node with boundary code 13 is the summit node.It has two destinations at NW and SW to the angular direction.Destination is to be represented in the position code to the northwest corner of the adjacent node of angular direction by it.And before it is appended to the destination ordered series of numbers, need also to check whether this destination is arranged in explosive area band ordered series of numbers and has been a member of destination ordered series of numbers.
Also have two kinds of sizes that method can be used for dwindling expanding node, or use the node of thick resolution layer approximate.When needs are in detail implemented first method during information.Its method is time present expanding node of branch, and expands each four fens quadrant of one deck down respectively.In this situation, present expanding node is handled as boundary node, and its boundary types is updated.This handles and is carried out with pulling over, up to the discovery adjacent node, or handles boundary node always.Second method is to utilize the series of strata characteristic of landform octa-tree.Be to reduce the quantity (and the size of therefore dwindling visibility chart) on summit, but not the size of node of expansion at present will wait the position code of the adjacent node of size to be appointed as boundary node, and the end extension process.That is approximate processing is that " amputation " is than the present low node of expansion resolution level.The boundary code of the node of having expanded at present upgrades as stated above.
3.1.3 destination location
Whenever adjacent node is positioned, it is presented at present direction and need further expands, otherwise this node has run into a boundary node.After all 4 main directions are all inspected, promptly obtain the boundary types of barrier node.From this boundary types, can determine directly whether this node is the barrier node.Extension process is carried out from adjacent node with pulling over, and uses barrier node ordered series of numbers with reference to the node of having expanded, to avoid repeating to inspect identical obstacle nodes.Fig. 7 shows the expansion of explosive area band.During extension process, whether the boundary types that obtains boundary node is the summit of explosive area band with decision.If it is the summit node, then produce a destination, shown in Fig. 7 b at " to the angular direction " adjacent risk district band.
After all members to the SEED ordered series of numbers apply extension process, just obtain along the direct explosive area band on the flight path between starting point and point of destination, it is relevant with the general direction of flight path.Fig. 8 a-d shows the flight district with dangerous node, and the barrier corresponding region on the internodal different direct-paths of starting point and point of destination.The information of gesture positively of explosive area band is to capture from specific landform octa-tree, and is converted into one group of destination.Then use these destinations to construct visibility chart in the navigation space, with the decision optimal path.
3.2 the conversion of navigation space
Visibility chart is constructed according to resulting one group of destination during obtaining the stage.This group destination has implied the geometry information of explosive area band in the navigation space.Algorithm is to consider that all points are to (W
From, W
To) constitute W wherein
FromAnd W
ToBe starting point, terminal point or the middle destination of explosive area band.Determine W
FromAnd W
ToWhether be the end points of aerial flight route segment, check W
FromAnd W
ToStraight line with respect to " collision " of explosive area band.Do not take place to interlock W and if only if connect the line segment of point-to-point transmission
FromAnd W
ToBetween node connected by the link in the visibility chart.
The principle of collision detection be used to check that the collision of the direct-path between the starting point point of destination is identical.As long as detect collision, the right test of destination promptly comes to an end and ends, otherwise test will continue to arrive W
ToTesting all possible destination to after making up, resulting result is a visibility chart, and its destination is the node of figure, and the route segment that destination constituted is the arc of circle.Have several paths in Fig. 9, they are made of the many straight lines that connect the point of starting point and purpose by the destination sequence.
Method used in employed visibility chart method and the most path planning problems is identical, and wherein the visibility chart in barrier space is constructed by polygon barrier ordered series of numbers.But, following consideration is at the flight path plan calculus method according to the landform octa-tree:
Gathering is along the obstacle nodes of the desirable direct-path between starting point and point of destination, and near those possible barriers that are limited to the direct-path (or direction) at present obtain the explosive area band.The method meaning contains incoherent dangerous knot removal in the navigation space, and therefore the quantity of destination is minimized.Because destination is only represented the subclass of the barrier of hazardous location, this processing provides the part visibility chart of whole navigation space.The example of Fig. 8 a-d display part structure and its visibility chart.
Will check altogether that during collision detection W (W-1)/2 destination is right, wherein W is the quantity that comprises the destination of starting point S and point of destination G.The time complexity that makes up visibility chart is proportional to W (W-2)/2.For any navigation space, can be easy to see the quantity of the quantity of destination W less than summit n.In addition, comprise the size of visibility chart of W destination less than the size of the visibility chart on n summit.Clearly, mat dwindles the speed that the size of visibility chart can significantly be promoted search.
3.3 flight path search
Describe in prosthomere, visibility chart is to represent with the form of the ordered series of numbers of flight path section, and path planning problem has converted the problem of searching the visibility chart between start node and destination node to.For example, Fig. 9 shows the visibility chart of the route segment of representing navigation space, and 7 nodes are arranged in the drawings, comprises beginning and point of destination.It is reconstructed into tree structure in order to its structure to be described, surpassing once appears in tree in destination node G and other node therein.
There is few techniques can be used for path among the search figure comprising such as depth-first, breadth-first and heuristic search.Heuristic search method is described in the preferred embodiment, add all restrictive conditions and make the number of connection of incorporating in the path planning algorithm minimum.During the search, the route segment process is selected, that is as far as possible away from present position, expectation is as far as possible near impact point, with the minimum method expectation acquisition data that is connected of the shortest method and search, assessment increases the influence of destination, and using that group destination of decision can be expanded in routine.
Seek the search that real optimal path need have no to omit.But, perhaps optimal path is not to be that space-time is desired with demand, because the performance in acquisition path is reduced.For nodes a large amount of in the visibility chart, the calculated load of method that covers nothing left is very surprising, can adopt more efficient heuristic search method, and it is according to the algorithm derived from Dijkstra, also is the A* method of knowing.
4. instant dynamic environment is used
As expected, the flight path of aircraft needs instant the modification with the coupling flying condition, and the barrier in the environment can change, will be according to present barrier space, for the change access topographic(al) data storehouse of flight program each time to rebuild visibility chart, plan that new flight path must finish in the several seconds so that accomplish instant navigation, this time interval comprises that flight path planning calculates, and framework path search space.
On the typical case, in instant navigational environment, new flight path need be finished in the several seconds of request.In fact, acquisition destination and Search Visibility figure institute's time spent are than the time much less of planning processing entire path.The strategy that will suggestion path planning algorithm be applied to instant dynamic environment is algorithm to be applied to have the starting point that produces at random and the specific landform gained of point of destination according to the observation, and measures each institute's time spent stage.These measurements comprise the time that produces destination, the time of framework visibility chart, and the time of finding the path in the different resolutions of landform octa-tree." adjustment " specifies the instant dynamically flight path plan calculus method of landform then to use the result of these calculated off-line times to be used for.
Change the resolution of navigation space, use four fens trees of pyramid structure to represent navigation space and dangerous node.Obtain pyramid structure K layer method and be on 2 * 2 window of K+1 layer, applying max function.But, in each layer of the top of pyramid structure, may make the path crested, therefore, in this layer, may can not find the path because of " merging " that tree-shaped node is only got the maximum elevation value.In instant application, preferably avoid setting up the big bottleneck that visibility chart caused at the high-res layer.On the other hand, avoid thick resolution layer also very important, it is easy to hide active path.The method of decision appropriate location reason resolution layer at first obtains destination at predefined resolution layer, estimates the size of visibility chart, and then whether decision has the layer that need switch to other to do path planning.
For example, Figure 10 is presented in the instant simulation that continuously changes point of destination during the aerial mission, and starting point is (255,101), and point of destination is (96,251).Predetermined air speed is 400 meter/second, and the layer of flying height and operation is set the interaction with the user for.During the flight, give the new new point of destination (241,242) of flight path planning; Algorithm is (204,148) according to the new starting point of restrictive condition prediction of 5-second.In identical layer, find the path, and flying height as shown in figure 10.Also can use different datum lines, divide factor, time restriction and flying height.
The source archives of DTED are height data of 1/5000th engineer's scales that provide of TaiWan, China State Central Univ. space and remote measurement research centre, are called digital terrain model data (DTM).The DTM archives are that the height value by each point of crossing of horizontal grid of 40 meters is constituted, and its value is to comprise level line on the SPOTLandmass map of 256K height value to make the mathematics interpolation and get from 20.48 square kilometres DTM square.Raw file can be greatly to 2
16* 2
16Individual net point, but be limited to 2 among the embodiment
9* 2
9Individual net point is with the processing of networking coding.
As previously mentioned, the path planning algorithm can be carried out by thick resolution layer in pyramid structure, to meet instant restrictive condition.But, the Terrain Elevation data is to change continuously, and landform octa-tree representation is relevant with landform, and therefore, barrier position and the connectivity relevant with specifying flying height are unpredictable.In general, the actual job layer that path planning is handled is by minimum flying height decision, its inevitable quantity that also determines destination, flying height is low will to produce a large amount of dangerous node and obstacle nodes, therefore, can be lower than predefined boundary value with the quantity that keeps destination for certain specific operating environment adopts thicker work layer.Owing to the performance of computing system is looked closely in instant application, the speed of aircraft is decided, instant restrictive condition, the time and the predefined processing layer that allow to plan can change.
5. terrain-avoidance and flight environment vigilance
5.1 dynamic barrier and weather condition are avoided
The present invention not only provides warning according to landform all around, and can give the landform information along flight path the place ahead, and it is to obtain from the path planning function.In case new path plans on line and finishes, promptly can be at an easy rate and the warning function coupling of GPWS and GCAS.The dangerous coverage area of other type also can one group of position code be represented such as barrier, mountain peak, weather conditions (thunderstorm, the wind that come across in the spatial domain are cut or any meteorological condition), covers and folds on landform altitude figure, and press preceding method and carry out.Figure 11 shows the example of embodiment.
5.2 landform altitude figure and terrain masking for landform vigilance
The generation of landform altitude figure, and explosive area band, mountain peak, the calculating of the sight line terrain masking of the barrier relevant with selected flying height and heading can identical position code be represented.Use the node parameter in the access algorithm acquisition relief block.I, J, the height of K parameter given plane position and node is assigned to each altitudinal belt from the different colour codings of the table of comparisons; S represents to constitute the zone that this node of this shaded areas is contained.The subclass of node derives from the zone that collision detection and searching have the equivalent node, represents explosive area band, mountain peak, and barrier.
5.3 the fluoroscopic image of relief block
A kind of method that produces the fluoroscopic image of relief block is provided, comprises from relief block acquisition and access data supplying to produce image.Use the parameter of node in the access algorithm acquisition relief block.I, J, the K parameter is given the height of planimetric position and node, is assigned to each altitudinal belt from the different colour codings of the table of comparisons; S represents to constitute the zone that the node of this landform fluoroscopic image is contained.Directly use relief block as input data, do not need the original DTED archives of access.Figure 12 shows the example of fluoroscopic image embodiment.
6. conclusion
The planing method of known technology is to use predefined barrier model.But, the term of execution of flight planning,, be with barrier region also to change whenever flying height changes.In addition, in the DTED of known technology method, the data quantity of acquisition and the cost of calculating all are negative factors, the complexity of algorithm increases in the standard of the being everlasting DTED system, best flight planning or urgent change path, all restriction that may be subjected to the DAQ amount and assess the cost in instant flight environment.
In the present invention, provide a kind of GFIT warning algorithm according to the octa-tree landform, it is with various resolution direct representation landform in various degree.Mat amputation of octa-tree structure or approximate unwanted data, can be at the level of thick resolution with enough degree of accuracy with relief blockization, allow to carry out efficiently the landform reference work.In this preferred embodiment, mat uses the feature of octa-tree relief block, the function that landform vigilance and warning system are relevant, and beguine is carried out more efficient according to the known method of DTED.In addition, compare with the flight preplanning system of known technology, preferred embodiment manifests the ability of instant flight path planning.
For the long-range in flight environment whole world path planning, no matter be or in instant flight environment, the decomposition texture of octa-tree hierarchy type is avoided the topographic details of path planning excess in the stage in planning in advance.Mat utilizes the heuristic characteristic of octa-tree relief block, and the path planning algorithm can be in any one deck operation of octa-tree landform.In addition, path planning method mat is set up the size of the part visibility chart of navigation space with the reduction search space, does not influence the selection in path and the details of avoidance landform.Octa-tree landform described in the invention and visibility chart method have been fit to instant requirement of calculating.
For warning relevant function and obstacle avoidance, for example can use and plan identical design with flight path with CFIG.Use octa-tree landform or additional one deck octa-tree landform and replace DTED, can implement to predict the comparison between flight path and topographic(al) data storehouse at an easy rate, use the possible collision of detecting and warn, or obtain new path for avoidance.In addition, can more efficient method carry out landform vigilance and demonstration.
Though more than described the representative embodiment of the present invention, this description is not to limit the scope of the invention, it can be implemented by various forms of embodiment.For example, the road path planning algorithm of flying immediately can be embedded in the flight management computer (FMC) as air traffic control.On the other hand, when in the mountain area or in the metropolitan area that buildings or man-made obstructions are arranged,, give in the application of aircraft forward sight ability, particularly General Aviation from instant flight path planning and flight path and topographic profile that the topographic(al) data storehouse of encoding obtains.Therefore, this ability can extend at an easy rate that barrier, ground are made and obstacle avoidance near warning with flying under control.In addition, landform vigilance and demonstration also can be coupled to passenger cabin news of flight demonstration (CDTI) becomes one of its characteristic.
Viewpoint from the topographic(al) data storehouse, with limited cost, relief block can use separately, or with the parallel use of the known technology of DTED data bank, even replace present DTED data bank, in military field, such as mission planning, terrain-avoidance, landform follow, terrain match, radar and threaten that sight line is covered, intervisibility covers etc. and all can implement.Application aspect non-aviation, such as sea bed represent, sonar is contained, the estimation of GSM base station covering scope etc., also can be suitable for.
Though the present invention is with reference to preferred embodiment demonstration and description, and illustrates in the mode of accompanying drawing, can not be considered as limitation ot it.Be familiar with the personage of technology in this respect, can imagine the various equivalent modifications that, delete and replace, and any special embodiment, can not depart from scope of the present invention.
Claims (23)
1, a kind of instant flight path is selected and the method for path planning for General Aviation is carried out, and it is characterized in that comprising the steps:
Use digital terrain height data (DTED) to produce relief block, this relief block comprises a group node, each this node comprises 4 parameter I, J, K, S, each height peak dot I with the DTED archives, J, the K mapping obtains 4 parameter I to the 3-D position code of corresponding octa-tree, J, K, S, parameter I, the 2-D coordinate of J definition planimetric position, add height K, I, J, the 3-D coordinate of K definition space position, introduce the division factor of height, it is divided into many bands with Terrain Elevation, the height that the parameter K representative is divided, in this octa-tree, the node that comes across division height values such as having in the identical four minutes quadrants of corresponding four minutes trees is merged, it can be non-linear dividing the factor, or since a baseline to replace the mean sea level height, parameter S is the covering scope of node, and increase it to be used for representing size of node, these 4 parameter I, J, K, S is with the integer of their representation node of bit position interleaved code formation;
Use this landform model that navigation space is provided;
Access and acquisition relief block are to produce the landform high-level diagram;
On navigation space, give starting point and point of destination, with the ground trace of the direct flight path of decision on the landform high-level diagram;
According to ground trace and flying height hazard recognition district band;
Use this explosive area band to make one group for the destination of avoiding;
Make up the visibility chart of navigation space, it is one group of collisionless route segment;
Mat flight path search algorithm connects starting point and point of destination; And
Obtain the topographic profile of flight path from relief block.
2, method according to claim 1 is characterized in that: this relief block is the octa-tree landform.
3, method according to claim 1 is characterized in that: this relief block is the four fens trees and the derivative type of octa-tree structure.
4, method according to claim 1 is characterized in that: each node is with an integer representation.
5, method according to claim 4 is characterized in that: each Terrain Elevation data has the node of its unique correspondence.
6, method according to claim 1 is characterized in that: this navigation space of definition is the zone that is used for disposing possible flight path;
This navigation space is in conjunction with octa-tree and four fens trees, to be provided at 3-D and the 2-D operation on the Terrain Elevation data; And
The deletion of K bit in the 3-D position code can be obtained the 2-D position code.
7, method according to claim 5 is characterized in that: the step that is able to this landform high-level diagram is as follows:
Use this relief block of access algorithm access;
Node of access is promptly represented the zone that this node of access is contained;
Use the acquisition algorithm to capture the parameter of the node of this relief block, I wherein, J, the K parameter is given the planimetric position and height of node, different colour codings from the table of comparisons are assigned to each altitudinal belt, and S represents to constitute the scope that the node of this landform high-level diagram is contained.
8, method according to claim 1 is characterized in that:
Ground trace is the straight line line segment, and its form is the ordered series of numbers of node;
The explosive area band is the ordered series of numbers of node, derives from the node that its height conflicts with flying height in the collision detection;
Each collisionless route segment is the straight line line segment, and its form is the ordered series of numbers of node;
Destination is shown in the position code of 2-D; And
Visibility chart be carry out each bar destination to the collision detection of line segment form to determine one group of collisionless path line segment framework.
9, method according to claim 1 is characterized in that: because the geometric areas feature of this explosive area band in the navigation space is used the path search algorithm according to visibility chart.
10, a kind of method of carrying out instant dynamic collision detection is characterized in that comprising the steps:
Use digital terrain height data (DTED) to produce relief block, this relief block comprises a group node, each this node comprises 4 parameter I, J, K, S, each height peak dot I with the DTED archives, J, the K mapping obtains 4 parameter I to the 3-D position code of corresponding octa-tree, J, K, S, parameter I, the 2-D coordinate of J definition planimetric position, add height K, I, J, the 3-D coordinate of K definition space position, introduce the division factor of height, it is divided into many bands with Terrain Elevation, the height that the parameter K representative is divided, in this octa-tree, the node that comes across division height values such as having in the identical four minutes quadrants of corresponding four minutes trees is merged, it can be non-linear dividing the factor, or since a baseline to replace the mean sea level height, parameter S is the covering scope of node, and increase it to be used for representing size of node, these 4 parameter I, J, K, S is with the integer of their representation node of bit position interleaved code formation;
Use this landform model that navigation space is provided;
Access and acquisition relief block are to produce the landform high-level diagram;
Ordered series of numbers according to the node on the flying height navigation by recognition space;
Give the ground trace of flight path line segment, it is the ordered series of numbers of the node on the landform high-level diagram; And
Mat is searched along the node ordered series of numbers of each node contrast explosive area band of path line segment, with decision and the afoul flight path line segment of explosive area band.
11, method according to claim 10 is characterized in that: performed collision detection is to check to come across identical node in two kinds of node ordered series of numbers.
12, a kind of method of carrying out instant dynamically weather conditions avoidance is characterized in that comprising:
Use digital terrain height data (DTED) to produce relief block, this relief block comprises a group node, each this node comprises 4 parameter I, J, K, S, each height peak dot I with the DTED archives, J, the K mapping obtains 4 parameter I to the 3-D position code of corresponding octa-tree, J, K, S, parameter I, the 2-D coordinate of J definition planimetric position, add height K, I, J, the 3-D coordinate of K definition space position, introduce the division factor of height, it is divided into many bands with Terrain Elevation, the height that the parameter K representative is divided, in this octa-tree, coming across the node that the division height value such as has in the identical four minutes quadrants of four fens trees of correspondence is merged, it can be non-linear dividing the factor, or since a baseline to replace the mean sea level height, parameter S is the covering scope of node, and increase it to be used for representing size of node, these 4 parameter I, J, K, S is with the integer of their representation node of bit position interleaved code formation;
Use this landform model that navigation space is provided;
Access and acquisition relief block are to produce the landform high-level diagram;
Give starting point and impact point to determine the ground trace of direct flight path on the landform high-level diagram in navigation space;
According to ground trace and flying height hazard recognition district band;
Give the weather conditions coverage area, it is to represent with the ordered series of numbers of node;
The node ordered series of numbers of weather coverage area is added to the node ordered series of numbers of explosive area band;
Use this new explosive area band to dispose one group of destination for avoiding;
Making up the visibility chart of new navigation space, wherein is one group of collisionless path line segment;
Link starting point and impact point with the flight path search algorithm; And
Obtain the topographic profile of flight path from relief block.
13, method according to claim 12 is characterized in that:
The weather conditions coverage area is one group of position code, is covered in this landform high-level diagram; And
Weather conditions can be thunderstorms, wind is cut or anyly come across aerial climate condition.
14, a kind of method of carrying out instant dynamic barrier avoidance is characterized in that comprising:
Use digital terrain height data (DTED) to produce relief block, this relief block comprises a group node, each this node comprises 4 parameter I, J, K, S, each height peak dot I with the DTED archives, J, the K mapping obtains 4 parameter I to the 3-D position code of corresponding octa-tree, J, K, S, parameter I, the 2-D coordinate of J definition planimetric position, add height K, I, J, the 3-D coordinate of K definition space position, introduce the division factor of height, it is divided into many bands with Terrain Elevation, the height that the parameter K representative is divided, in this octa-tree, the node that comes across division height values such as having in the identical four minutes quadrants of corresponding four minutes trees is merged, it can be non-linear dividing the factor, or since a baseline to replace the mean sea level height, parameter S is the covering scope of node, and increase it to be used for representing size of node, these 4 parameter I, J, K, S is with the integer of their representation node of bit position interleaved code formation;
Use this landform model that navigation space is provided;
Access and acquisition relief block are to produce the landform high-level diagram;
Give starting point and impact point to determine the ground trace of direct flight path on the landform high-level diagram in navigation space;
According to ground trace and flying height hazard recognition district band;
Give the zone that barrier is contained, it is to represent with the ordered series of numbers of node;
Barrier coverage area node ordered series of numbers is added to explosive area band node ordered series of numbers;
Use this new explosive area band to dispose one group for the destination of avoiding;
Making up the visibility chart of new navigation space, wherein is one group of collisionless path line segment;
Link starting point and impact point with the flight path search algorithm; And
Obtain the topographic profile of flight path from relief block.
15, method according to claim 14 is characterized in that: the barrier coverage area is one group of position code, is covered in this landform high-level diagram; And
Barrier can be landform, mountain peak and any man-made obstructions.
16, a kind of method of carrying out instant terrain masking for landform vigilance is characterized in that comprising:
Use digital terrain height data (DTED) to produce relief block, this relief block comprises a group node, each this node comprises 4 parameter I, J, K, S, each height peak dot I with the DTED archives, J, the K mapping obtains 4 parameter I to the 3-D position code of corresponding octa-tree, J, K, S, parameter I, the 2-D coordinate of J definition planimetric position, add height K, I, J, the 3-D coordinate of K definition space position, introduce the division factor of height, it is divided into many bands with Terrain Elevation, the height that the parameter K representative is divided, in this octa-tree, the node that comes across division height values such as having in the identical four minutes quadrants of corresponding four minutes trees is merged, it can be non-linear dividing the factor, or since a baseline to replace the mean sea level height, parameter S is the covering scope of node, and increase it to be used for representing size of node, these 4 parameter I, J, K, S is with the integer of their representation node of bit position interleaved code formation;
Use this landform model that navigation space is provided;
Access and acquisition relief block are to produce the landform high-level diagram;
According to the ground trace of flight path and flying height hazard recognition district band, mountain peak, and barrier coverage area;
Calculate the terrain masking of sight line; And
According to the parameter I of hazardous location, J, K, S are that terrain masking and vigilance are specified colour coding.
17, method according to claim 16 is characterized in that: each node all is to represent with integer.
18, method according to claim 16 is characterized in that: this calculating sight line terrain masking is to use the sight line terrain masking of identical position code representation calculating about selected flying height and heading;
Explosive area band, mountain peak and barrier are to represent with the subclass of the node of relief block, and are to obtain from collision detection and the zone of seeking the equivalent node; And
I, J, the K parameter is given the planimetric position and the height of node, is assigned to each altitudinal belt from the different colour codings of the table of comparisons; The S representative constitutes the covering scope of this node of this shaded areas.
19, method according to claim 17 is characterized in that: each Terrain Elevation data has the node of its unique correspondence.
20, a kind of method that produces the fluoroscopic image of relief block is characterized in that comprising:
Use digital terrain height data (DTED) to produce relief block, this relief block comprises a group node, each this node comprises 4 parameter I, J, K, S, each height peak dot I with the DTED archives, J, the K mapping obtains 4 parameter I to the 3-D position code of corresponding octa-tree, J, K, S, parameter I, the 2-D coordinate of J definition planimetric position, add height K, I, J, the 3-D coordinate of K definition space position, introduce the division factor of height, it is divided into many bands with Terrain Elevation, the height that the parameter K representative is divided, in this octa-tree, the node that comes across division height values such as having in the identical four minutes quadrants of corresponding four minutes trees is merged, it can be non-linear dividing the factor, or since a baseline to replace the mean sea level height, parameter S is the covering scope of node, and increase it to be used for representing size of node, these 4 parameter I, J, K, S is with the integer of their representation node of bit position interleaved code formation;
Use this landform model that navigation space is provided; And
From relief block access and acquisition parameter I, J, K, S is to produce fluoroscopic image.
21, method according to claim 20 is characterized in that each node is with an integer representation.
22, method according to claim 21 is characterized in that the node that each Terrain Elevation data has its unique correspondence.
23, method according to claim 20, it is characterized in that: this access and acquisition parameter I, J, K, S comprises: directly use relief block as input data, do not need the original DTED archives of access, I wherein, J, the K parameter is given the height of planimetric position and node, different colour codings from the table of comparisons are assigned to each altitudinal belt, the scope that the node of the fluoroscopic image of this landform of S representative formation is contained.
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| CN 99110076 CN1105954C (en) | 1999-07-02 | 1999-07-02 | Route planning, terrain evading and fly environment warming system for general-purpose aviation |
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| CN 99110076 CN1105954C (en) | 1999-07-02 | 1999-07-02 | Route planning, terrain evading and fly environment warming system for general-purpose aviation |
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| CN1105954C true CN1105954C (en) | 2003-04-16 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102288196A (en) * | 2010-05-14 | 2011-12-21 | 株式会社电装 | Navigation unit |
| TWI634402B (en) * | 2015-10-06 | 2018-09-01 | 經緯航太科技股份有限公司 | Airline planning system of unmanned airplane and method thereof |
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| CN105786019A (en) * | 2016-04-27 | 2016-07-20 | 广州极飞电子科技有限公司 | Aerial carrier flight control method and aerial carrier flight control system |
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- 1999-07-02 CN CN 99110076 patent/CN1105954C/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102288196A (en) * | 2010-05-14 | 2011-12-21 | 株式会社电装 | Navigation unit |
| CN102288196B (en) * | 2010-05-14 | 2013-11-06 | 株式会社电装 | Navigation unit |
| TWI634402B (en) * | 2015-10-06 | 2018-09-01 | 經緯航太科技股份有限公司 | Airline planning system of unmanned airplane and method thereof |
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