DE102007043025A1 - Airport operating method, involves outputting control signals corresponding to passages such that tractor is coupled to aircraft and/or moved from surface to another surface for conveying actual condition of airport to optimal condition - Google Patents

Abstract

The method involves detecting an actual condition of an airport, and representing the actual condition in a Petri-net. Accessibility-graphs are computed from the Petri-net based on the actual condition, and the graphs are checked with respect to critical conditions. A series of passages is determined, and control signals corresponding to the passages are output such that an aircraft tractor (12.2) is coupled to an aircraft (38.1) and/or moved from a moving surface to another moving surface for conveying the actual condition of the airport to calculated optimal condition of the aircraft. An independent claim is also included for an airport comprising two aircraft tractors.

Description

The Invention relates to a method for operating an airport, the at least two aircraft tugs, endpoints in the form of at least one Aircraft stand area and at least one aircraft tug stand area for the aircraft towers, movement areas in Form of a runway that has a first end and a second end, at least a runway between the aircraft floor space and the Runway and at least one feeder route for the aircraft towers, crossing points between movement surfaces and a guide to Controlling the aircraft tug includes. According to one second aspect, the invention relates to such an airport.

A generic airport and a method for operating an airport are from the WO 2003/078250 A1 known. It describes a method for autonomously transporting an aircraft on the ground between a runway and a parking position in which the aircraft is transported without its own aircraft propulsion. For this purpose, the aircraft is picked up on the main landing gear by an aircraft tractor, which is pulled by cables running under the runway.

A similar system is from the US 5 078 340 known, which relates to a method for transporting aircraft on the ground in the range of parking positions. An advantage of such systems is that a transport of aircraft with ground vehicles significantly less fuel needed than an independent roles of the aircraft. A disadvantage of the known systems is that they are inflexible. Thus, the aircraft tractors can only be moved along such slopes in which cables are present. Another disadvantage is the complex maintenance. If there is a fault in the cable system, there is also a risk that the entire airport will be shut down. A further disadvantage is that no safety analyzes and no optimal strategies for the use of aircraft tractors are known for such a novel ground traffic transport system.

• (a) Modellieren des Flughafens als Petri-Netz, wobei (i) die Endpunkte und die Kreuzungspunkte als Plätze, (ii) die Bewegungsflächen, die Flugzeugschlepper und Flugzeuge als Marken und (iii) Bewegungen der Flugzeugschlepper als Übergänge der zugeordneten Marke von einem Platz zu einem anderen Platz modelliert werden,
• (b) Erfassen eines aktuellen Zustands des Flughafens,
• (c) Darstellen des aktuellen Zustands im Petri-Netz,
• (d) Errechnen eines Erreichbarkeitsgraphen aus dem Petri-Netz ausgehend von dem aktuellen Zustand,
• (e) Überprüfen der Erreichbarkeitsgraphen auf kritische Zustände
• (f) gegebenenfalls Sperren von Übergängen, die zu dem kritischen Zustand führen,
• (g) aus den verbleibenden, erlaubten Übergängen Ermitteln einer Folge von Übergängen in einen optimalen zukünftigen Zustand,
• (h) Ausgeben von der Folge von Übergängen entsprechenden Steuersignalen, so dass mindestens einer der Flugzeugschlepper an ein Flugzeug ankoppelt und/oder sich von einer Bewegungsfläche zu einer anderen Bewegungsfläche bewegt, so dass sich der momentane Zustand des Flughafens in den optimalen zukünftigen Zustand ändert und
• (i) kontinuierliches Wiederholen der Schritte (b) bis (h).

The invention is based on the object to overcome disadvantages in the prior art. The invention solves the problem by a method for operating a generic airport with the steps:

• (a) modeling the airport as a Petri net, where (i) the endpoints and crossing points as places, (ii) the movement areas, the aircraft tugs and aircraft as brands, and (iii) aircraft tugs movements as transitions of the assigned mark from a place be modeled to another place,
• (b) detecting a current status of the airport,
• (c) representing the current state in the Petri net,
• (d) calculating an accessibility graph from the Petri net based on the current state,
• (e) checking the reachability graph for critical conditions
• (f) optionally blocking transitions leading to the critical condition,
• (g) determining, from the remaining allowed transitions, a sequence of transitions into an optimal future state,
• (h) outputting control signals corresponding to the sequence of transitions so that at least one of the aircraft tractors attaches to an aircraft and / or moves from one movement surface to another movement surface such that the current state of the airport changes to the optimal future state and
• (i) continuously repeating steps (b) through (h).

According to one second aspect, the invention solves the problem by a generic airport, wherein the guide is set up to carry out an inventive Process.

Advantageous The invention is offset by drastic fuel savings the roles are self-propelled achievable. This is advantageous inventive system also very flexible, so that, for example, delays caught by aircraft can be.

Especially It is advantageous that the safety of the process or the airport is mathematically detectable. It is therefore sufficient for the In air traffic common, high security requirements. Advantageous In addition, the system is easily reconfigurable. For example the number of aircraft to be towed per unit time varies, so more or less aircraft tugs can be used become. Another advantage is that the system is in the frame a test operation can be operated teilautonom, the Issued control signals to an operator of the aircraft tractor which will be an additional plausibility check perform the movement to be performed by the aircraft tractor can. Another advantage is that accidents due to pilot error or pilot errors are largely excluded. The system is simplified also the work of the pilots.

In the present description under the current state of the airport the Totality of all brands understood. The detection of the current state can be done for example via sensors or people. For example, sensors may be present in the movement surfaces, which detect whether an aircraft or an aircraft tractor is located on the respective movement surface. Such sensors may be radar or radio sensors, for example.

Under the representation of the current state in the Petri net becomes particular understood that the totality of all brands of aircraft tractors assigned to the squares on which the marks aircraft tugs are currently located. Under the calculation of the accessibility graph from the Petri net, starting from the current state, the corresponding process is in accordance with the Petri net theory understood. In particular, for all possible transitions due to the transitions reachable states of Airport calculated, the reachability graph a depth of n has. This means that n successive transitions be considered according to the current state. The depth n depends significantly on the available standing computing power for implementing the inventive Procedure used computer system available. The bigger the depth n, the more advantageous the process. Very cheap it is when the depth n is greater than fifty and for example, less than one hundred.

Under checking the reachability graph critical states is to be understood in particular that The states encoded in the reachability graph are then checked whether for such a condition the safety of the Operation of the airport is at risk or if he is at a deadlock leads. Such a deadlock results, for example then when two aircraft tugs are in opposite directions move and in the course of the same movement area would have to use. A critical state is thus in particular such a state of the airport, the valid aviation safety rules would contradict or involve vehicles such as aircraft and aircraft tugs would block each other.

Under the locking of transitions leading to the critical State lead, in particular, to understand that prevents is that in the further process, a control signal is generated, due to which aircraft tugs would move so that a critical condition occurs. To determine the optimally future To stands, for example, a, in principle arbitrary, evaluation function which assigns a value to each transition. Such Evaluation function is, for example, the cost of the transition or the roll time.

In In a preferred embodiment, the airport is called colored Petri net modeled as this descriptive means a compact presentation and hierarchical structuring and automatic analysis.

According to one preferred embodiment, the detection of the current State automatically performed, in particular by the Aircraft towers transmit absolute or relative coordinates by radio to transmit a central office. For example, it is possible that the aircraft tractors via a triangulation bearing too fixed at the airport stations arranged their relative position determine to these channels. Alternatively or additively determine the Aircraft tugs their absolute coordinates through a satellite Navigation system.

Prefers the sequence of transitions has a depth of 50 or more transitions, so a sufficient To enable projection into the future. This is however depending on the airport topology. The bigger the depth is, the greater the probability that the determined optimal future state also After a long time in retrospect as an optimal choice it turns. The lower the depth, the less Computing power is needed.

In a preferred embodiment comprises determining of the optimal future state, the steps of calculating a rating number that represents a cost and / or a time requirement coded for the transition, for all transitions, summing up all rating numbers for all transitions, which lead to a state of highest depth, so a condition score is obtained and a select a state of minimum state score as optimal future Status. An advantage of this is that the method so with a high certainty only a little from a cost point of view deviates from optimal method.

Around on the one hand react quickly enough to changes to be able to and on the other hand with a comparatively small Computing power to get along, the steps (b) to (h) are preferred depending on the event and / or at a time interval of repeated for several minutes.

The Aircraft tractors can be particularly effective and flexible be used when the control signals transmitted by radio to the aircraft tractors become. To prevent interference and sabotage attempts, the control signals are preferably coded.

To wait for a plane A preferred embodiment of the method includes the steps of detecting a landing time of an aircraft approaching the runway and blocking transitions that result in a condition in which no aircraft tug for towing the aircraft away from the runway at landing time is available.

In a preferred embodiment comprises an inventive Airport at least two aircraft tractors, each with a chassis, a motor and a coupling device for coupling the aircraft tractor to a landing gear of an aircraft, wherein the coupling device via a quick-mounting device is attached to the chassis and a main landing gear adapter for connecting to a main landing gear of the aircraft and a nose gear adapter for connecting to a Nose gear of the aircraft includes. Alternatively, the tug be composed of separate, self-propelled modules over Couplings are coupled together. The aircraft tug is so preferably modular, so that he for each Purpose, for example, to a mass of the towed aircraft can be coordinated. It is also possible the aircraft tug on different geometries of main or nose gear and their Orientation relative to each other.

Around also to be able to adjust the engine power is preferred provided that one or more self-propelled motor modules with its chassis between the buggy module and the main landing gear module be coupled. For increased automation is the Aircraft tractor also preferably self-propelled.

Around be able to record the condition of the airport at any time, include individual, but especially all movement surfaces Advantageously, sensors for detecting aircraft tugs.

in the The invention is based on exemplary embodiments explained in more detail. It shows

1 a schematic view of an airport according to the invention,

2 a graphic representation of a Petri-net representation of a part of the airport after 1

3 an accessibility graph for the Petri net according to 2 .

4 a schematic representation of an interaction between the guidance of the airport and its other components and

5 a schematic representation of an aircraft tractor according to the invention of an airport according to the invention.

1 shows an airport 10 with aircraft tugs 12.1 . 12.2 , ..., aircraft stands 14.1 . 14.2 , an aircraft tug stand 16 (hatched), a first runway 18 (shown in dotted lines), which is a first end 20 and a second end 22 owns and a second runway 24 (shown in dotted lines), which is a first end 26 and a second end 28 has.

The airport 10 also includes a first runway 30.1 (Runways are shown dotted like pistes) and a second runway 30.2 that the second runway 24 each at their first end 26 or second end 28 with the plane stand 14 connect. A third runway 30.3 leads from the aircraft stand area 14 also to the first end 26 the second runway 24 and a runway 30.4 also connects the second end 28 with the plane stand 14 facing an apron 32 is arranged. A fifth runway 30.5 leads from the first end 26 the second runway 24 to the first end 20 , the first runway 18 and a sixth runway 30.6 connects the second end 22 the first runway 18 with the second end 28 the second runway 24 , The airport 10 is from a virtual tower 34 controlled from.

At the airport 10 are the aircraft tugs 12.1 . 12.2 , ... track-guided and it is a roadway system 36 for the aircraft tractors 12 provided by the route network for aircraft 38.1 . 38.2 , ... is disconnected. In the present specification, reference numerals without counting suffix indicate the corresponding object each as such.

The aircraft tractors can be realized in different ways. Examples are rail-bound aircraft tractors with diesel, gas or electric motors. It is also possible, the aircraft tractors 12 carry out with magnetic levitation with long stator or provide virtual tracking using satellite navigation, video image processing and radio bearing. Through the aircraft tugs 12 are the ground movements of the aircraft 38 before and after landing, largely automatic, comparable to rail transport, with control and optimal resource allocation as described below.

2 shows a model of the airport 10 in the form of a state machine in the form of a Petri net 40 , In the Petri net 40 Places are drawn as ellipses, with endpoints and intersections points of movement surfaces are modeled as places. Places thus represent, for example, the aircraft stand areas 14.1 . 14.2 in 1 , where in 2 just 14.1 Shown is the aircraft tractor stand areas 16.1 and 16.2 , where in 2 just 16.1 is shown and crossing points 70.1 like the one between piste 24.1 and runway 30.4 ,

Transitions, represented as rectangles in Petri nets, represent the transitions between squares. In the airport topology they map the movement areas (slopes, runways, ...). The directed edges, as connecting lines between squares and transitions, indicate the possible directions of movement of the aircraft and aircraft tugs via the movement areas (transitions) from crossing point / platform (square) to crossing point / platform (square). Aircraft and aircraft tugs are represented as brands. For example, the mark means 72.1 / 38.1 that the aircraft tug 72.1 by plane 38.1 is connected and both form a composite. For the period of transport of the aircraft by the aircraft tug, the transport resource becomes aircraft tugs in the Petri net 40 occupied by the aircraft. The process dynamics are represented in Petri nets by switching the transitions and the associated brand flow. By switching the transitions, a moving surface in the form of the second runway 30.2 the brand flows 72.1 / 38.1 to 70.2 ie the plane 38.1 is from the aircraft tractor 72.1 from crossing point 70.1 towards intersection point 70.2 towed. This is the taxiway 30.4 used.

Important is the resource limitation inherent in the Petri net and the formally derived analysis of the accessibility of all possible system states. Another important feature is the possibility of hierarchical structuring of Petri nets for complex systems over subnets. In 2 only the highest hierarchy is shown. Different process levels are displayed on correspondingly different network hierarchy levels. In the example, the transition "apron" represents 32 a subnet that describes the processes on the apron at a terminal building.

• 1. Festlegung eines Netzwerkes von Wegstrecken und Kreuzungspunkten zur Beschreibung der Bodenverkehrsflüsse auf den Flughafen. (a) Die Bewegung (Schleppen) über ein Wegstück wird als Prozess im Petri-Netz durch das Schalten einer Transition beschrieben. (b) Das Erreichen eines Kreuzungspunktes als Prozesszustand wird durch die Belegung eines Platzes mit einer Marke beschrieben.
• 2. Festlegen von Regeln zur Benutzung der Wegstrecken durch Flugzeuge, dies umfasst Nutzungsstrategien (z. B. Nutzung in eine Richtung oder in beide Richtungen) und Ressourcenbeschränkungen (z. B. Nutzungsobergrenzen). (a) Wegstücke werden als Ressourcen verstanden und durch Marken ihre Auslastung im Petri-Netz repräsentiert. Art und Umfang der verfügbaren Markierungen beschreiben die Nutzungsart der Wegstücke. (b) Frei verfügbare Wegstücke befinden sich in einem Ressourcenspeicher und stehen den Verkehrsobjekten zur Nutzung zur Verfügung. Ressourcenspeicher werden im Petri-Netz als Plätze realisiert.
• 3. Erfassung möglicher Flugzeuge und deren für den Transport relevanten Eigenschaften (z. B. Gewichtsklasse). (a) Flugzeuge sind die dynamischen Objekte im Flughafenbodenverkehrsprozess und werden durch Marken repräsentiert. (b) Durch Färbung (Attributierung) der Marken erfolgt die Zuweisung von Eigenschaften, wie z. B. die Gewichtsklasse eines Flugzeugs

In the following, the steps for the construction of a Petri net for modeling the airport and its operational control are described in detail. In a first step, an analysis of the description of the ground handling system is made. In a second step, the formulation of the description object follows on the basis of a system-theoretical representation. In a third step, the description item is formalized using colored Petri nets. In detail, the following steps are processed:

• 1. Definition of a network of routes and intersections describing the ground traffic flows to the airport. (a) Movement (towing) over a span is described as a process in the Petri net by switching a transition. (b) Achieving a crossing point as a process state is described by occupying a place with a mark.
• 2. Establish rules for the use of the routes by aircraft, including usage strategies (eg unidirectional or bi-directional use) and resource constraints (eg usage limits). (a) Distances are understood as resources and brands represent their utilization in the Petri net. The nature and extent of the available markings describe the usage of the way pieces. (b) Freeways are located in a resource repository and are available for use by the traffic objects. Resource storages are realized in the Petri net as places.
• 3. Recording of possible aircraft and their relevant properties for transport (eg weight class). (a) Aircraft are the dynamic objects in the airport ground handling process and are represented by brands. (b) By staining (attribution) of the marks, the assignment of properties, such as. B. the weight class of an aircraft

Derivation of the requirements for automated airport transportation:

• 4. Introduction of aircraft tugs and defining the requirements for them (a) Aircraft tug are transport resources in the system and are represented as brands. (B) By coloring the marks, the assignment of properties, such as B. Weight class of transportable aircraft. (C) The use of different aircraft tugs for the towing process of different aircraft weight classes can by using different tractor performance classes or realized by coupling together several standardized motor modules become.
• 5. Identification of suitable aircraft tractors, Determining quantity and capacity. (a) Aircraft tug parking are resource stores (storage for aircraft tractors) and are represented as a place in the Petri net.
• 6. identification of necessary support processes, such. B. a connection of aircraft and aircraft tractor. (a) The coupling process of aircraft with aircraft tractors is a process and is described by the switching of a transition. The result is the merger of two brands into one product. (b) The provision of aircraft tugs (trip to the coupling point) as a process is also described by switching a transition.

A crucial aspect for the operators of the ground transportation system, which increasingly take on supervisory control as automation progresses, is the timely identification of critical system conditions. This is done by continuous calculation of the so-called reachability graph. Accessibility graphs, which can be generated automatically from the Petri net, discrete event-discreetly all variants in the course of traffic, which can occur in the Petri net in a given aircraft-aircraft tug scenario. In the 3 For example, for a two-aircraft scenario, different aircraft tug configurations are shown.

One Reachability graph forms all of them based on the current time possible alternatives in the traffic flow. It can optimal traversal paths identified, selected and implemented or critical paths are identified and excluded early become.

The Possibility of a periodically recurring accessibility analysis Allows input of changing process data in the expiring scenario.

For At any time, for example, the state of the airport can be in Form of a graph or in the form of an equivalent Matrix formulated. Out of this current state can become usually a variety of other states arise, for example by placing an aircraft and / or an aircraft tug from one position be moved to another position. All possible, states that emerge in a reachability graph shown. The procedure for creating a reachability graph Standard literature can be taken from a Petri net.

3 shows such a reachability graph 42 , wherein the initial state of in 2 shown current state is. The accessibility graph 42 discovers event-discrete all variants in the traffic flow, which can occur in the Petri net and was created with the computer program CPN Tools, which represents standard software. As can be seen, the reachability graph points 42 a depth n of nine. This means that, starting from the original state, nine transitions to a subsequent state are calculated, if possible. The set of end nodes (four in the present case, corresponding to depth n = 12) represents the possible transports.

All in the reachability graph of 42 States represented as (rounded) square symbols are checked to see if they represent a critical state. That is, they are checked to see if they encode a state of the airport that conflicts, for example, with applicable safety regulations. If so, the transition leading to the invalid state is disabled. From the possible future states in depth n = 12, which in 3 to the far right, becomes the optimal future state 74 selected. For this the roll times are evaluated. This means that in each case the time is calculated that is necessary to bring the state into the respective final state. The final state that is most quickly reached, or for which the taxiing time of the towed aircraft is minimized, is selected as the optimal future state.

By introducing boundary conditions and constraints, such as positioning and route assignment of the aircraft tractors, in the Petri net, the reachability graph extent is constrained to optimal transport. Locking transitions to critical states ensures that the airport is always safe States can assume. After the optimal future state is determined, the transitions leading to the optimally future state are extracted from the reachability graph. Subsequently, by radio via a radio system 44 ( 1 ) encoded control signals to the aircraft tractors 12 Sent so that they move so that the airport 10 comes in the optimal future state.

The airport 10 also includes sensors 46.1 . 46.2 , ..., those in the runways 30.1 . 30.2 , ... and the other traffic areas are embedded, and which record whether an aircraft tractor 12 or an airplane 38 or both are located on the respective movement area or on the respective end point.

4 shows a schematic overview of the method described above. The current state of the airport 10 corresponds to a current state in a Petri net 40 , Based on this Petri net 40 becomes an accessibility graph 42 calculated and critical states, such as the state 48 , are locked, as by a cross 50 is indicated.

It remains in the in 4 In the simplified example shown, two possible future states Z1 and Z2 are selected, under which the optimal future state is selected. In a subsequent step, control signals 52 sent out the airport 10 bring in the assumed optimal state Z2. After expiration of a given time becomes another reachability graph 40 ' which is based on the state Z2 and can lead to the future states Z3, Z4 and Z5, wherein Z5 is rejected as an invalid state, the transition from Z3 is locked in the state Z5.

The supervision system state of the airport, that is, the approaching, landing and takeoff aircraft and the aircraft tug takes place by means of a ground traffic monitoring system with data fusion (ASMGCS, Advanced Surface Movement Guidance and Control System), whose information is the basis for the Petri net control panel supplies. Critical situations, such as runway incursions, are avoided because all traffic flows in the hands of the monitoring center in the form of a virtual Towers are lying. This makes pilot mistakes impossible, like for example, an unallowable roll on an unreleased Piste due to ignorance of local conditions or faulty communication.

The planes 38 After landing, the first taxiway entrance to the runway will be occupied by an aircraft tug 12 taken over, so that already here the engines of the aircraft can be switched off and the responsibility passes from the pilot to a taxi driver in the virtual tower as a supervisor of the automatic transmission. The aircraft towers remotely controlled by the virtual tower via the Petri net 12 transport the aircraft 38 track guided by suitable guidance systems. The transport of the aircraft 38 From a gate to the runway for the start is quite analogous with the same system, so that here too, the turbines are started just before the start to warm up.

5 shows an aircraft tractor 12 according to a preferred embodiment, a chassis 54 , a motor 56 in the form of a diesel engine and a coupling device 58 for coupling the aircraft tractor 12 to a not schematically drawn aircraft 38 includes. The coupling device 58 in turn includes a main landing gear adapter 60 consisting of two sub-elements for the respective wheelsets of the aircraft 38 consists. The coupling device 58 also includes a nose gear adapter 62 , which is a nose landing gear of the aircraft 38 can record.

At least one self-propelled engine module 56 on the chassis 54 is coupled via couplings between main landing gear module and nose landing gear module, with the number of engine modules or engine performance class depending on the weight category of the aircraft to be towed. Via a schematically drawn radio unit 64 can the aircraft tug 12 Receive and transmit radio signals. The radio unit 64 is in connection with an electrical control 66 using position sensors 68.1 . 68.2 is electrically connected and which is adapted to the aircraft tractor 12 lead tracked at the airport.

10

Airport

12

aircraft tractor

14

Aircraft stand area

16

Aircraft tractor-footprint

18

first piste

20

first The End

22

second The End

24

second piste

26

first The End

28

second The End

30

runway

32

advance

34

virtual Tower

36

track system

38

plane

40

Petri net

42

reachability graph

44

radio system

46

sensor

48

critical Status

50

cross

52

control signal

54

chassis

56

engine

58

coupling device

60

Main gear adapter

62

Bugfahrwerksadapter

64

radio unit

66

electrical control

68

position sensor

70

crossing points

74

optimal Status

n

depth

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

• WO 2003/078250 A1 [0002]
• - US 5078340 [0003]

Claims (14)

Method for operating an airport ( 10 ), the - at least two aircraft tractors ( 12 ), - endpoints, in the form of at least one aircraft footprint ( 14 ) and at least one aircraft tug stand ( 16 ) for the aircraft tractors ( 12 ), - movement areas, in the form of a slope ( 18 ; 24 ), the first ( 20 ; 26 ) and a second end ( 22 ; 28 ), at least one runway ( 30 ) between the aircraft footprint ( 14 ) and the slopes ( 18 ; 24 ) and at least one feeder route for the aircraft tractors ( 12 ), and - intersecting points between movement surfaces, comprising the steps of: (a) modeling the airport ( 10 ) as a Petri net ( 40 ), where (i) the end points and the crossing points as places, (ii) the movement areas as transitions, (iii) the occupation of the movement areas and the aircraft tugs as brands and (iv) movements of the aircraft tugs as transitions of the assigned brands of a place to another place are modeled, (b) detecting a current state of the airport ( 10 ), (c) representing the current state in the Petri net ( 40 ), (d) calculating an accessibility graph ( 42 ) from the Petri net ( 40 ) starting from the current state, (e) checking the reachability graphs ( 42 ) to critical states ( 48 ) (f) if necessary, blocking of transitions leading to the critical state ( 48 g) from the remaining, allowed transitions determining a sequence of transitions into an optimal future state, (h) outputting control signals corresponding to the sequence of transitions ( 52 ), so that at least one of the aircraft tractors ( 12 ) to an aircraft ( 38 ) and / or moves from one movement surface to another movement surface, so that the current state of the airport ( 10 ) is transferred to the calculated (simulated) optimal state of the airport, and (i) continuously repeating steps (b) through (h). Method according to claim 1, characterized in that the airport ( 10 ) as a colored Petri net ( 40 ) is modeled. Method according to one of claims 1 or 2, characterized in that the detection of the current state is carried out automatically, in particular by the aircraft tractors ( 12 ) transmit absolute or relative coordinates by radio to a central office. Method according to one of claims 1 to 3, characterized in that the sequence of transitions a depth (s) of four, five, six, seven or more comprises successive transitions, in particular of more than fifty transitions. Method according to one of claims 1 to 4, characterized in that determining the optimum future State includes the following steps. - For all transitions calculating a rating number, which encodes a cost for the transition, - Sum up all rating numbers for all transitions, which lead to a state of highest depth, so that a condition score is obtained, and - Choose a state of minimum state score as optimal future state. Method according to one of claims 1 to 5, characterized in that the steps (b) to (h) in a time interval from 0.1 min to 10 min to be repeated. Method according to one of claims 1 to 6, characterized in that control signals ( 52 ) by radio to the aircraft tractors ( 12 ). Method according to one of claims 1 to 7, characterized by the steps: - Detecting a landing time of an aircraft ( 38 ) in the approach to the slopes ( 18 ; 24 ) and - blocking of transitions that lead to a state in which no aircraft tugboat (at the time of landing) 12 ) for towing the aircraft ( 38 ) from the slopes ( 18 ; 24 ) is available. Airport which (a) has at least two aircraft tractors ( 12 ), (b) endpoints in the form of at least one aircraft footprint ( 14 ) and at least one aircraft tug stand ( 16 ) for the aircraft tractors ( 12 ) (c) Movement areas, in the form of slopes ( 18 ; 24 ), which is a first end ( 20 ; 26 ) and a second end ( 22 ; 28 ), at least one runway ( 30 ) between the aircraft footprint ( 14 ) and the slopes ( 18 ; 24 ) and at least one feeder line ( 36 ) for the aircraft tractors ( 12 ), and (d) crossing points between movement surfaces and (e) a control device for controlling the aircraft towers ( 12 ), characterized in that the guide device is set up for carrying out a method according to one of the preceding claims. Airport ( 10 ) according to claim 9, characterized in that at least two aircraft tractors ( 12 ) each (a) a chassis ( 54 ), (b) a motor ( 56 ) and (c) a coupling device ( 58 ) for coupling the aircraft tractor ( 12 ) to a landing gear of an aircraft ( 38 ) connected to the chassis via a quick-release device ( 54 ) and (i) a main landing gear adapter ( 60 ) for connection to a main landing gear of the aircraft ( 38 ) and (ii) a nose landing gear adapter ( 62 ) for connecting to a nose gear of the aircraft. Airport ( 10 ) according to one of claims 9 or 10, characterized in that the engine ( 56 ) via a quick mounting device to the chassis ( 54 ) is attached. Airport ( 10 ) according to one of claims 9 to 11, characterized in that the aircraft tractors ( 12 ) are self-propelled. Airport ( 10 ) according to one of claims 9 to 12, characterized in that the aircraft tractors ( 12 ) are self-propelled. Airport ( 10 ) according to one of claims 9 to 13, characterized in that movement surfaces sensors ( 46 ) for detecting aircraft tugs ( 12 ).