Aircraft flight management system

Abstract

An aircraft flight management system comprising: a first non-critical or open-world module (MO) for generating an enhanced flight plan, the first module (MO) being configured to iteratively generate the enhanced flight plan through the following steps: initialization of pseudo-constraints; and iterative improvement of the choice of pseudo-constraints, until an improvement target is reached or no improvement is achieved compared to the last best choice of pseudo-constraints, based on at least one optimization criterion and at least one parameter representative of the aircraft's flight environment; a second critical or certified flight management module (FMS) for trajectory calculation, comprising at least one critical computer and / or at least one critical software component to calculate and output a safe trajectory, based on the enhanced flight plan provided by the first module (MO). Figure for the abstract: [Fig.1]

Description

Title of the invention: Aircraft flight management system

[0001] The present invention relates to a flight management system for an aircraft.

[0002] The invention relates to the field of on-board systems, and more particularly the optimization of the trajectory of an aircraft.

[0003] In the context of the present invention, the avionics systems are secure on-board systems meeting regulatory constraints of integrity and availability. These avionics systems are characterized by a level of criticality, linked to the level of integrity and the level of availability, imposed by the regulatory standards in force.

[0004] Integrity means the ability of a system to perform a required function correctly. Availability means the ability of a system to perform a required function under given conditions, at a given time or during a given time interval. A "non-avionics" or "open world" system means systems that are not onboard and / or that do not meet the same regulatory constraints of integrity and availability.

[0005] The criticality levels are for example defined in the RTCA DO178-C and EUROCAE ED-12C standards, by five criticality levels (from A to E) defined as follows: Level A: A defect in the system or subsystem under study can cause a catastrophic problem - Flight safety or compromised landing - Aircraft crash. Level B: A defect in the system or subsystem under study can cause a dangerous problem resulting in serious damage or even the death of some occupants. Level C: A defect in the system or subsystem under study may cause a major problem resulting in malfunction of the device's vital equipment. Level D: A defect in the system or subsystem under study may cause a minor problem with no effect on flight safety. Level E: A defect in the system or subsystem under study may cause a problem with no effect on flight safety.

[0006] These 5 levels are also called DAL levels (acronym for "Design Assurance Level" in English). The Levels are established by the functional safety studies. These studies then set the DAL level for the hardware and software in accordance with safety standards (Eurocae ED-79 and SAE ARP4754 "Certification considerations for Highly-Integrated and Complex Aicraft Systems") or aircraft manufacturer directives (ABD100, ABD200,...). The DAL level of a subsystem can be different from the system level provided that the DAL level of the system is achieved by an adequate hardware / software architecture.

[0007] The invention can be applied in the field of air transport, whether it be scheduled aviation, business aviation, aerial work, remotely piloted aircraft or autonomous aircraft.

[0008] Currently, in an onboard aircraft flight management system, or FMS for "Flight Management System" in English, one of the most complex functions is the calculation of the trajectory and predictions (fuel, performance, arrival time), from the aircraft's flight plan. This function is complex because it manages flight optimization and multiple constraints. The processing requires a large computing capacity of the processor or CPU for "Central Processing Unit" in English, and a specific real-time architecture.

[0009] Currently, the trajectory calculation and prediction function is fully implemented on certified avionics systems. The steps for calculating this function are as follows: - Development of the flight plan, - Calculation of the Trajectory, and - Guidance along the trajectory.

[0010] There are numerous patent documents relating to FMS flight management systems, some of which relate to a link between the critical avionics domain and less critical domains (i.e. less critical avionics or non-avionics also called open world).

[0011] For example, document US 10,295,349 B2 is known, which relates to an aircraft flight management system that secures data provided by the non-avionics or open world domain. This document is based on an architecture with two FMS flight management systems, one validating non-critical data from the open world, while the other continues to conduct the flight. This system requires the operation of two FMS flight management systems in parallel, which is costly in terms of resources and financially.

[0012] The traditional approach of optimizing the trajectory in critical certified avionics generates increasingly heavy costs, which are not economically viable.

[0013] Also known is document FR3019912 which relates to a system and method for determining the flight parameters and fuel consumption of at least one flight phase of an aircraft. This document relates to a solution for optimizing flight in the open world.

[0014] Also known is document US20100191458 which relates to a system and method for optimizing flight plans in the open world.

[0015] Existing solutions do not make a close link between avionics and the open world: an optimized flight plan is calculated in the open world, then the FMS calculates a trajectory following this optimized flight plan. But the optimization done in the open world does not take into account the characteristics of the FMS used.

[0016] Furthermore, regardless of the level of optimization performed on the flight plan in the open world, the degree of optimization of the trajectory is limited by the capabilities of the FMS employed.

[0017] Furthermore, optimization methods in the open world do not take into account the known flaws of FMS in terms of optimization.

[0018] An aim of the invention is to address the problems cited above, and in particular to increase the accuracy of the calculations for optimizing the flight of an aircraft in a field where operational performance requirements require increasingly complex algorithms based on more and more data, while controlling the development costs which are significant for the production of certified on-board systems.

[0019] According to one aspect of the invention, there is provided an aircraft flight management system comprising: - a first non-critical or open world module for developing an improved enriched flight plan, comprising at least one non-critical computer, and / or at least one non-critical software, for, from a reference flight plan comprising a first set of constraints, the value of at least one parameter of a second set of parameters representative of the aircraft flight environment, and at least one optimization criterion of a third set of optimization criteria, calculating and delivering as output, an improved enriched flight plan comprising the first set of constraints and at least one pseudo-constraint of a fourth set of pseudo-constraints, intended for a second critical avionics flight management module, for which the enriched flight plan is specifically optimized,

[0020] the first module being configured to develop the improved enriched flight plan iteratively by the following steps: - initialization of pseudo-constraints of the fourth set; - iterative improvement of the choice of pseudo-constraints of the fourth set until an objective of improvement of a trajectory calculated by the second critical avionics FMS flight management module is reached, or absence of improvement compared to the last best choice of pseudo-constraints, from at least one optimization criterion of the third set and at least one parameter of the second set. - the second critical or avionics flight management module certified for trajectory calculation, comprising at least one critical computer and / or at least one software critical to calculate and output a safe trajectory, from the enhanced enriched flight plan provided by the first module.

[0021] In one embodiment, the first module is configured to perform the step of initializing pseudo-constraints of the fourth set randomly, or according to a predefined process.

[0022] According to one embodiment, the first module is configured to implement the step of iterative improvement of the choice of the pseudo-constraint(s) of the fourth set by iteration of the following steps: - calculation and storage of the trajectory that the second module would calculate from a flight plan including the constraints of the reference flight plan and the current pseudo-constraints; - evaluating whether the current trajectory calculated is improved compared to the trajectories calculated in the previous iterations, based on the optimization criterion(s) of the third set, the value of at least one environmental parameter of a second set, and the improvement objective; and - if the objective is achieved, output of the iterative improvement of the flight plan enriched with the current pseudo-constraints, and otherwise modification of the current pseudo-constraints for the following iteration.

[0023] According to one embodiment, the first set of constraints comprises: - points to fly over; - a lateral trajectory to follow; - altitudes or altitude ranges to be respected; - speeds or speed ranges to be respected; and - passage times to be respected.

[0024] According to one embodiment, the second set of parameters representative of the aircraft flight environment comprises information concerning: - the weather; - air traffic; - the weight and balance of the aircraft throughout the flight; and / or - the thermal and / or electrical energy available on board the aircraft.

[0025] In one embodiment, the third set of optimization criteria comprises: - minimization of travel time; and / or - minimization of fuel consumed and flight condensation trails; and / or - minimization of a difference between a theoretical flight arrival time and a calculated arrival time (punctuality); and / or - minimization of turbulence.

[0026] According to one embodiment, the optimization criterion(s) are selectable by the pilot of the aircraft.

[0027] In one embodiment, the fourth set of pseudo-constraints comprises - points to fly over; - a lateral trajectory to follow; - altitudes or altitude ranges to be respected; - speeds or speed ranges to be respected; and - passage times to be respected.

[0028] In one embodiment, the first module is configured to perform the iterative improvement by gradient descent, or a genetic algorithm, or simulated annealing.

[0029] According to another embodiment of the invention, an aircraft is also provided with a flight management system as previously described.

[0030] The invention will be better understood by studying some embodiments described as non-limiting examples and illustrated by the appended drawings in which:

[0031] - [Fig.l] schematically illustrates a flight management system of an aircraft, according to an aspect of the invention;

[0032] - [Fig.2] schematically illustrates the operation of the system of [Fig.l], according to an aspect of the invention.

[0033] [Fig.l] schematically illustrates a flight management system, according to one aspect of the invention.

[0034] The flight management system of an aircraft comprises a first non-critical MO or open world module for developing an improved enriched flight plan. The first MO module comprises at least one non-critical computer, and / or at least one non-critical software, and calculates and outputs, from a reference flight plan comprising a first set of constraints, the value of at least one parameter of a second set of parameters representative of the environment of the flight of the aircraft, and at least one optimization criterion of a third set of optimization criteria, an improved enriched flight plan comprising the first set of constraints and at least one pseudo-constraint of a fourth set of pseudo-constraints, intended for a second critical avionics FMS flight management module, for which the enriched flight plan is specifically optimized.

[0035] The first MO module is configured to develop the improved enriched flight plan iteratively by the following steps: - initialization of pseudo-constraints of the fourth set; - iterative improvement of the choice of pseudo-constraints of the fourth set, until an improvement objective is reached, or absence of improvement of a tra jectory calculated by the second critical avionics FMS flight management module with respect to the last best choice of pseudo-constraints, from at least one optimization criterion of the third set and at least one parameter of the second set.

[0036] The flight management system of an aircraft also comprises the second critical or avionics flight management module (FMS) certified for trajectory calculation, comprising at least one critical computer and / or at least one critical software for calculating and outputting a safe trajectory, from the improved enriched flight plan provided by the first MO module.

[0037] The first MO module is configured to perform the step of initializing pseudo-constraints of the fourth set randomly, or according to a predefined process.

[0038] [Fig.2] schematically represents the operation of the flight management system of an aircraft.

[0039] The first MO module is configured to implement the step of iterative improvement of the choice of the pseudo-constraint(s) of the fourth set by iteration of the following steps: - calculation and storage of the trajectory that the second FMS module would calculate from a flight plan including the constraints of the reference flight plan and the current pseudo-constraints; - evaluating whether the current trajectory calculated is improved compared to the trajectories calculated in the previous iterations, based on the optimization criterion(s) of the third set, the value of at least one parameter of a second set, and the improvement objective; and - if the objective is achieved, output of the iterative improvement of the flight plan enriched with the current pseudo-constraints, and otherwise modification of the current pseudo-constraints for the following iteration.

[0040] The first set of constraints may include: - points to fly over; - a lateral trajectory to follow; - altitudes or altitude ranges to be respected; - speeds or speed ranges to be respected; and - passage times to be respected.

[0041] The second set of parameters representative of the aircraft flight environment may include information concerning: - the weather (current and forecast); - air traffic (in flight and at airports); - the weight and balance of the aircraft throughout the flight; and / or - the energy available on board the aircraft (thermal or electrical).

[0042] The third set of optimization criteria may include: - minimization of travel time; and / or - minimization of fuel consumed and flight condensation trails; and / or - minimization of a difference between a theoretical flight arrival time and a calculated arrival time (punctuality); and / or - minimization of turbulence.

[0043] The optimization criterion(s) may be selectable by the pilot of the aircraft.

[0044] The fourth set of pseudo-constraints may include: - points to fly over; - a lateral trajectory to follow; - altitudes or altitude ranges to be respected; - speeds or speed ranges to be respected; and - passage times to be respected.

[0045] The first MO module may be configured to perform the iterative improvement by gradient descent, or a genetic algorithm, or simulated annealing.

[0046] As a variant, the invention also proposes an aircraft equipped with a flight management system as previously described.

[0047] The present invention makes it possible to improve the efficiency of the augmented FMS, by analyzing its operation.

[0048] From the reference flight plan, the improved enriched flight plan also called optimal flight plan, the trajectory calculated by the second FMS module, the trajectory actually flown, data on flight conditions (weather, ATM communication and AOC), and feedback from the pilots, one or more experts can write a new algorithm to develop the enriched flight plan, taking into account all the data from several flights.

[0049] Data collection allows data to be sent from the aircraft to a ground computing unit (cloud or other).

[0050] The update is performed by a maintenance operator who downloads the new algorithm inside the aircraft.

[0051] The analysis may use Artificial Intelligence techniques.

[0052] The update can be carried out via a computer network between the aircraft and the ground computing unit.

[0053] The present invention has the following advantages: - Trajectory optimization: this invention maximizes the optimization capacity of the second FMS module, making the most of its qualities and avoiding its defects. - Functional augmentation: the first open world MO module can offer functions not existing in the second certified FMS module, while ensuring that it is perfectly compatible with the interfaces of the second FMS module. - Reducing the complexity of certified software: The second certified FMS module can remain relatively simple, as opposed to the first open-world MO module, which concentrates all the algorithmic optimization complexity. Reducing the complexity of certified algorithms reduces the number of requirements, lines of code and therefore tests. - Reduced hardware requirements: Reducing the CPU footprint of certified algorithms, and therefore the real-time architecture of the software, reduces the power required by certified computers, and therefore reduces costs by using older and / or lighter hardware. For non-certified calculations, a COTS computer can be used, which allows for better SWaP (Size, Weight and Power). - Adapting to future needs: Traditionally, the developments of the second FMS module have mainly focused on improving trajectory optimization and taking into account an increasing number of constraints. Moving these efforts into the open world allows for much greater agility in developments and facilitates adaptation to future needs. - Compatibility with new technologies: the first open world MO module offers the possibility of using techniques that are very difficult to certify, such as the use of Artificial Intelligence. Indeed, the final calculation of the trajectory is always carried out by the certified FMS and can be verified by the pilot. - Certified FMS Core Stability: Functional variability can be carried by the open world application. The algorithms of the second certified FMS module are not impacted by new requirements.

Claims

Demands

1. An aircraft flight management system comprising: - a first non-critical or open-world module (MO) for generating an enhanced enriched flight plan, comprising at least one non-critical computer, and / or at least one non-critical software, for calculating and delivering, from a reference flight plan comprising a first set of constraints, the value of at least one parameter from a second set of parameters representative of the aircraft's flight environment, and at least one optimization criterion from a third set of optimization criteria, an enhanced enriched flight plan comprising the first set of constraints and at least one pseudo-constraint from a fourth set of pseudo-constraints, for a second critical avionics flight management module (FMS), for which the enriched flight plan is specifically optimized,The first module (MO) is configured to develop the enhanced flight plan iteratively through the following steps: - initialization of pseudo-constraints from the fourth set; and - iterative improvement of the choice of pseudo-constraints from the fourth set, until an objective is achieved for improving a trajectory calculated by the second critical flight management avionics module (FMS), or until no improvement is achieved compared to the last best choice of pseudo-constraints, based on at least one optimization criterion from the third set and at least one parameter from the second set; - the second critical or flight management avionics module (FMS) is certified for trajectory calculation, comprising at least one critical computer and / or at least one critical software component to calculate and output a safe trajectory, based on the enhanced flight plan provided by the first module (MO).

2. System according to claim 1, wherein the first module (MO) is configured to perform the pseudo-constraint initialization step of the fourth set randomly, or according to a predefined process.

3. A system according to any one of the preceding claims, wherein the first module (MO) is configured to implement the iterative improvement step of choosing the pseudo-constraint(s) of the fourth set by iterating through the following steps: - calculation and storage of the trajectory that the second module (FMS) would calculate from a flight plan including the constraints of the reference flight plan and the current pseudo-constraints; - evaluation if the calculated current trajectory is improved compared to the trajectories calculated in previous iterations, according to the optimization criterion or criteria of the third set, the value of at least one environmental parameter of a second set, and the improvement objective; and - if the objective is achieved, output of the iterative improvement of the flight plan enriched with the current pseudo-constraints, and otherwise modification of the current pseudo-constraints for the next iteration.

4. A system according to any one of the preceding claims, wherein the first set of constraints includes: - points to be overflown; - a lateral trajectory to be followed; - altitudes or altitude ranges to be respected; - speeds or speed ranges to be respected; and - passing times to be respected.

5. A system according to any one of the preceding claims, wherein the second set of parameters representative of the aircraft's flight environment includes information concerning: - weather; - air traffic; - the mass and center of gravity of the aircraft throughout the flight; and / or - the thermal and / or electrical energy available on board the aircraft.

6. A system according to any one of the preceding claims, wherein the third set of optimization criteria includes: - minimization of travel time; and / or - minimization of fuel consumed and contrails of flight; and / or - minimization of a difference between a theoretical arrival time of the flight and a calculated arrival time; and / or - minimization of turbulence.

7. A system according to any one of the preceding claims, wherein the optimization criterion or criteria are selectable by the aircraft pilot.

8. A system according to any one of the preceding claims, wherein the fourth set of pseudo-constraints comprises: - points to be hovered over; - a lateral trajectory to follow; - altitudes or altitude ranges to respect; - speeds or speed ranges to respect; and - passage times to respect.

9. System according to any one of the preceding claims, wherein the first module (MO) is configured to perform the iterative improvement by gradient descent, or a genetic algorithm, or simulated annealing.

10. Aircraft equipped with a flight management system according to one of the preceding claims.

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