Locks – Hasp – Key lock
Reexamination Certificate
2000-08-17
2002-01-01
Cuchlinski, Jr., William A. (Department: 3661)
Locks
Hasp
Key lock
C244S075100, C244S190000
Reexamination Certificate
active
06334344
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a process for producing trajectories for an airborne vehicle.
It applies in particular, although not exclusively, to civil or military aviation and to airborne vehicles flown or alternatively guided from the ground.
In general, correct execution of the mission of an airborne vehicle relies on the defining of a flight plan which is produced during mission preparation. This flight plan comprises, among other things, a nominal trajectory to be followed during the mission, defined in a five-dimensional space: latitude, longitude, altitude, flight time and fuel reserves. However, unforeseen events may occur during execution of the mission, making the nominal trajectory envisaged during mission preparation unsuitable, or even obsolete. These events may, for example, consist in a breakdown of a vital part of the airborne vehicle, new weather conditions, a change in objective, or the emergence of a danger area crossed during that part of the nominal trajectory that remains to be covered. It is therefore necessary, during flight, to alter that part of the intended nominal trajectory that remains to be covered, with a view to jeopardizing the mission objectives as little as possible.
The nominal trajectory chosen during mission preparation is defined by a series of compulsory waypoints to pass through according to altitudes, headings, schedules, with minimum fuel reserves and, possibly, by positions and extended areas of danger that are to be avoided.
A modification, during flight, of a part of the nominal trajectory assigned during mission preparation that has yet to be covered, in order to take account of an event which was not taken into consideration during mission preparation is a difficult task because it has to be finalized quickly even though there are a great many obvious options for reconfiguring the nominal trajectory, among which it is difficult to discern, quickly, the one which best satisfies the numerous constraints encountered, whether these be associated with the airborne vehicle flight conditions, its maneuverability, its fuel-dependent range or the objectives of the mission, this difficulty being all the greater as these constraints often translate into contradictory requirements such as safety, economy, effectiveness, for example.
Attempts have therefore been made at easing the task of an aircraft pilot when the need to modify the nominal trajectory arises during flight, by providing him with the assistance of an automatic device which proposes to him a reconfigured trajectory that can be used by an automatic pilot system and by a cartographic display, and which is optimized from the point of view of satisfying the instantaneous constraints imposed by the flight conditions of the airborne vehicle, its maneuverability, its fuel-dependent range, the objectives of the mission and the relative importance attributed to these at that particular time.
The various processes for recalculating trajectories can be executed by an on-board computer which may or may not be assisted by an operator, allowing the pilot of an airborne vehicle in the course of performing a mission to be proposed a reconfiguration of his nominal trajectory by an automatic pilot system and by a cartographic display and minimizing the impact that an unforeseen event has on the safety and effectiveness of his mission.
Some of these processes call on cost optimization methods. These determine, as a function of the spatio-temporal position and of the maneuverability of the airborne vehicle, all of the detour paths that satisfy the new constraints imposed by the unforeseen event and which allow the nominal trajectory to be regained as quickly as possible keeping to the schedule and fuel-dependent range envisaged at the time of mission preparation and then proceed to select, of all the possible detour paths, the one which presents the minimum cost, that is to say the one which is optimum in terms of mission safety, economy and effectiveness. The cost of a trajectory is evaluated on the basis of its routing over a cost area superposed on the region overflown during the mission. The cost area is defined using a grid of points with a uniform mesh size, the actual size of which depends on the desired accuracy, each point in the grid being allocated a preference score devised according to the mission constraints in terms of effectiveness and safety. The cost of a trajectory corresponds to the inverse of the sum of the preference scores allocated to each point encountered on the cost area. These processes require an on-board computer with high processing power and a great deal of memory to implement them because they involve updating the cost area in real time to take account of the advent of an unforeseen event, followed by the detailed calculation, still in real time, of a number of possible detour paths and a calculation of their respective costs.
Other processes, calling upon levels of representation of a mission in greater or lesser detail, attempt to study a great many alternative solutions with a view to assigning them an effectiveness or risk criterion. However, in order to be able to provide an answer in real time, these processes require a great deal of processing power which is incompatible with the power of the computers which currently are fitted on board airborne vehicles. Furthermore, they require the intervention of the pilot, who has to divert his attention from the current mission to examine all the proposed solutions, of which there may be a great many, in order to select one of them. In this context, the pilot does not have control over the time when he has to make his choice, because the solutions put forward very soon become obsolete because of the speed with which the airborne vehicle is moving. What this means is that these processes are ineffective when the pilot needs to give his full attention to flying or the use of other systems (for example weapons or communications systems).
The use of artificial intelligence techniques and more specifically of a system employing a knowledge base and rules, and known by the name of expert system, has also been proposed for determining the reconfigured trajectory to be proposed to the pilot as being the one that is the result of the best compromise between the various requirements of the moment. However, an expert system requires the compiling of a knowledge base and of rules which is difficult to develop for determining a three-dimensional trajectory which also involves time, speed and other parameters, and evaluating its effectiveness at meeting the objectives of the mission as a function of a great many other criteria.
In order to solve this problem, European Patent Application EP 0 617 349 has proposed the use of multiexpert techniques which allow a number of expert systems with knowledge bases and rules each specialized in a given area to collaborate with each other. The process for determining the new trajectory comprises:
analyzing the context and interpreting the event that justifies the reconfiguring of the trajectory in order to determine the actions to be carried out,
breaking said actions down into alternatives each consisting of a sequence of elemental actions that can be performed by at least one of the specialist modules,
selecting each alternative in turn, using a certain strategy,
processing the alternatives selected which, for each alternative, consists in using the specialist expert modules to produce a trajectory using the elemental actions that make up the selected alternative, and evaluating the benefit of the trajectory obtained against at least one criterion, and
selecting at least one trajectory which has the best evaluation and presenting it as a solution associated with its evaluation.
This process is still fairly unwieldy to employ because it involves determining a collection of trajectory reconfiguring solutions and choosing the best one from among these.
The present invention proposes a process for reconfiguring a trajectory in real time wh
Bonhoure Fabienne
Inglese Fabien
Cuchlinski Jr. William A.
Hernandez Olga
Thomson-CSF Sextant
LandOfFree
Method for real time reconfiguration of trajectories for an... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for real time reconfiguration of trajectories for an..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for real time reconfiguration of trajectories for an... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2849022