Method for planning the operation of an aerial vehicle, control unit for an aerial vehicle and aerial vehicle with such a control unit

Abstract

An all-inclusive method for planning the operation of an aerial vehicle, in particular an eVTOL, which operation is divided into different operational areas each with its own individually validatable and inspectable planning methodology, including (i) pre-processing data on a computer basis on the ground before takeoff of the aerial vehicle; (ii) taking along pre-planned results of the data pre-processing in the form of a database (33, 44) on board the aerial vehicle, preferably after transferring the pre-planned results into the database (33, 44) on board the aerial vehicle; (iii) combining the pre-planned results by means of a computer-based decision logic (28) with planning steps at the flying time in accordance with a state of the aerial vehicle recorded by sensors for generating a current flight path; and (iv) controlling the aerial vehicle along the current flight path.

Claims

1. A method for planning an operation of an aerial vehicle, said operation being divided into different flight phases each having an individualized planning methodology, the flight phases including at least two of a takeoff phase, a landing phase, a final approach phase, and a corridor phase, each individualized planning methodology being individually validatable and inspectable, the method comprising: pre-processing data on a ground-located computer basis before takeoff of the aerial vehicle to generate one or more flight paths for each flight phase of the different flight phases, wherein the pre-pre-processing includes preparing available data records and preplanning of a set of flight paths for each flight phase that is as complete as possible of all flight paths relevant during operation; taking along pre-planned results of the one or more flight paths for each flight phase as a database on board the aerial vehicle; combining the pre-planned results for the different flight phases using a computer-based decision logic with planning steps at a time of flying in accordance with a state of the aerial vehicle recorded by sensors for generating a current flight path based on the one or more flight paths for the different flight phases; and controlling the aerial vehicle along the current flight path.

2. The method as claimed in claim 1, wherein planning methodologies specifically designed for a respective flight phase are used for all relevant operational states of the aerial vehicle.

3. The method as claimed in claim 1, further comprising, for a planning environment that is known before planning of a specific flight connection, initially generating and making available risk models for the planning in addition to geographical maps, surface models and other environmental data records.

4. The method as claimed in claim 1, further comprising, based on knowledge of physical flying properties of the aerial vehicle, calculating flight paths and maneuvers that are useable in a later course of planning in advance.

5. The method as claimed in claim 1, further comprising, for an incoming planning request, conducting the pre-processing on a ground-based computing system, and transferring the pre-processing of the one or more flight paths for each flight phase to the database in the aerial vehicle, wherein said database comprises a flight path database and also a maneuvers database and is used during flight to reduce planning to a decision-making problem, in which a most suitable flight path in the database is selected in each case.

6. The method as claimed in claim 5, further comprising, for events or emergency situations that the database does not cover, activating an on-line planning algorithm which, based on the maneuvers database, restores a safe flying state that is provided in the database by corresponding activation of the aerial vehicle.

7. The method as claimed in claim 1, further comprising, for planning of flight phases that are not critical to safety, conducting planning of an altitude profile of a flight path decoupled from planning in a horizontal plane utilizing different two-dimensional planning approaches on the altitude profile.

8. The method as claimed in claim 1, further comprising, for an unplanned event, providing a number of safe reaction possibilities using different planning approaches implemented in parallel for different contingency scenarios, with contingency planning being divided into a preplanning approach and an on-line planning approach.

9. The method as claimed in claim 8, wherein the contingency planning takes place such that alternate routes for less critical events are already taken into account in the preplanning and are stored with nominal flight paths in a trajectories database.

10. The method as claimed in claim 1, further comprising utilizing planning modules that cover the different flight phases across operational states.

11. The method as claimed in claim 1, further comprising taking into account emergencies that decisively impair flying safety or maneuverability of the aerial vehicle or are outside a regulatorily admissible range in a separate planning approach that is for restoring a safe operational state or, if required, ending a mission with minimal damage or injury to the aerial vehicle and persons involved.

12. The method as claimed in claim 11, further comprising performing a corresponding algorithm as an emergency planning algorithm for on-line planning, in which associated emergency maneuver calculations are carried out before takeoff and stored in the database.

13. The method as claimed in claim 12, further comprising taking into account existing restrictions of maneuverability of the aerial vehicle by excluding the emergency maneuvers concerned from a planning space.

14. The method as claimed in claim 12, further comprising coupling the emergency planning algorithm with a function for real-time perception of an environment.

15. The method as claimed in claim 1, further comprising, during the flight, classifying a flying state using a decision logic or a decision module based on at least one of physical information about the aerial vehicle or an environment, and selecting a planning methodology suitable for the flying state.

16. The method as claimed in claim 1, further comprising, as long as a suitable branching point between different trajectories along a flight path can be reached, resolving events or conflicts that are not critical to safety at a logic level, by diverting to a conflict-free trajectory by a change of trajectory at the branching point, and for a required change between pre-planned trajectories outside branching points, carrying out the change within predefined geographical zones using a real-time contingency on-line planning algorithm.

17. A control unit for an aerial vehicle, for operating and controlling the aerial vehicle, which operation is divided into different flight phases each having an individualized planning methodology, the flight phases including at least two of a takeoff phase, a landing phase, a final approach phase, and a corridor phase, said planning methodologies being individually validatable and inspectable, the control unit comprising: a computer-based data pre-processing unit that is at least one of ground-based or on board the aerial vehicle that is configured to pre-process data on a ground-located computer basis before takeoff of the aerial vehicle to generate one or more flight paths for each flight phase of the different flight phases, wherein the pre-pre-processing includes preparing available data records and preplanning of a set of flight paths for each flight phase that is as complete as possible of all flight paths relevant during operation; a database, which is taken along on board the aerial vehicle, that includes pre-planned results of the data pre-processing unit as the one or more flight paths for each flight phase are stored; a computer-based decision logic on board the aerial vehicle configured for: combining the pre-planned results of the one or more flight paths for each flight phase from the database using the decision logic; carrying out additional planning steps at a time of flying in accordance with a measured state of the aerial vehicle; and generating a current flight path based on the one or more flight paths for the different flight phases; and a controller in operative connection with the decision logic for controlling the aerial vehicle along the current flight path.

18. An aerial vehicle, comprising a control unit as claimed in claim 17.

19. The aerial vehicle according to claim 18, wherein the aerial vehicle is an eVTOL.

20. The aerial vehicle according to claim 18, wherein planning methodologies specifically designed for a respective flight phase are used for each relevant operation state of the aerial vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further properties and advantages become apparent from the following description of exemplary embodiments with reference to the drawing.

(2) FIG. 1 shows a possible configuration of the aerial vehicle according to the invention;

(3) FIG. 2 shows a concept of a mission planning architecture, such as on which a method according to the invention may be based;

(4) FIG. 3 shows a flow diagram of the mission planning process within the framework of a method according to the invention; and

(5) FIG. 4 shows the assignment of planning components depending on the time of execution within the framework of a method according to the invention.

DETAILED DESCRIPTION

(6) FIG. 1 shows an aerial vehicle 1 according to the invention in the form of a multicopter with 18 drive units (actuators). In FIG. 1, L, M and N denote the moments about the axes x, y and z (rolling axis, pitching axis and yawing axis) of the aerial vehicle 1, and F denotes the overall thrust. Reference sign 2 symbolizes the (main) flight control of the aerial vehicle 1, which preferably has at reference sign 2a a control unit (computing unit) according to the invention and required control and planning algorithms 2aa and also a database 2ab and generally is configured for carrying out the method according to the invention and its developments, in particular by using software. Additionally shown at reference sign 2b is a human pilot, which is not of any further note in the present case. Reference sign 3 denotes one of the 18 (unrestrictedly identical) drive units or actuators, in each case comprising an (electric) motor 3a and a rotor 3b. Reference sign 4 denotes by way of example a sensor unit operatively connected to the main flight control unit 2 or the control unit 2a, in order in a development of the method according to the invention to be able to take into account the available states of the aerial vehicle and environmental conditions by means of sensors. Although not shown, a multiplicity of such sensor units 4 may be provided, in particular inertial measuring units, GNSS, barometers, vibration sensors at the actuators, temperature sensors at the actuators, and the like. Reference sign 5 symbolizes a further computing unit (data pre-processing unit), which is not on board the aerial vehicle 1 but is stationed on the ground. Preferably taking place on this ground-based computing unit 5 is the preplanning further explained in detail above, the results of which are subsequently transferred to the control unit 2a of the aerial vehicle 1 and are stored there in the database 2ab. Although only one database 2ab is shown in FIG. 1, there may also be a number of databases, or the database 2ab may be divided into a number of databases, in particular the trajectories database mentioned further above and the maneuvers database likewise mentioned further above.

(7) However, the invention is not in any way restricted to the presence of a ground-based computing unit 5. It goes without saying that all of the planning operations, that is to say also the preplanning, can be carried out on board the aerial vehicle 1, as long as it has sufficient computing power. As a person skilled in the art appreciates, the planning operations may also be divided as desired between the ground-based computing unit 5 and the control unit (computing unit) 2a of the aerial vehicle 1.

(8) FIG. 2 shows on a conceptual level the division of the multi-dimensional planning space into separate planning approaches for operational states and flight phases and also the higher-level planning process, as it can be performed in the course of the method according to the invention. This is shown in the form of a conceptual mission planning architecture, in which, depending on an operational state of the aerial vehicle and a flight phase, different path planning methods are used in order to produce at any time a planning solution adequate for the situation. The mission planning architecture referred to is preferably formed by software within the control unit 2a (compare FIG. 1) (denoted in FIG. 1 as a whole by the reference sign 2aa).

(9) Shown at reference sign 20 in FIG. 2 are preprocessed and prepared aerial-vehicle and environmental data, which may for example and without restriction comprise for example a flight envelope, geo-data, risk maps or a landing site database. Reference sign 21 denotes the altitude profile planning referred to further above, while reference sign 22 stands for the maneuver calculation or maneuver machine calculation. Preferably, according to reference sign 20, the data are included in the altitude profile planning 21 and the maneuver calculation 22. In particular, the maneuvers calculated at reference sign 22 may be stored in the already mentioned maneuvers database.

(10) Reference sign 23 stands for the nominal planning, while reference sign 24 stands for the contingency planning. The former comprises at reference sign 23a a path planner with an objective function for nominal states of the aerial vehicle. The objective function is a function of the parameters of the objective in dependence on one or more input variables. In the nominal case, it is a metric that considers mission risk and energy efficiency. Also comprised at reference sign 23b is a so-called corridor planner, which implements an operating concept for the bidirectional use of a flight path identified in advance in the nominal planning. For this, travel paths separated horizontally and vertically from one another, on which aerial vehicles can fly in opposite directions at a safe distance, are generated on the basis of the original flight path. The flying altitude is adapted in accordance with existing air traffic rules. Any difference in altitude there may be is bridged by means of helix maneuvers. The contingency planning 24 comprises at reference sign 24a a first path planner (contingency planner 1) with an objective function for contingency states. Furthermore, it comprises at reference sign 24b a second path planner (contingency planner 2) with an objective function for contingency states. Reference signs 24a and 24b denote in the specific case the contingency off-line planner (24a) and the on-line planner (24b), as already explained further above. A precondition is the preplanning of a database with contingency flight paths in a tree structure. On each trajectory, paths to all available alternate landing sites are planned at constant time intervals. This call takes place as long as the still remaining time interval until landing is less than that of the planner call (new planning interval), or until another termination criterion (for example coverage) is reached. The exact planning approach for calculating the database is of secondary concern, as long as the database can be validated before departure. A planning solution must be verifiable and validatable by the competent authorities before departure. This arises from the requirements for precalculated flight paths in accordance with SC-VTOL. In the specific case, this means that the planning approach is of secondary concern as long as the planning solution before departure is in a format that can be checked for correctness and conformity with the rules either by machine or by a person.

(11) In this context, so-called wavefront algorithms can be used, by means of which navigation functions can be calculated for a number of parameters of an objective. Also implemented in particular are navigation functions, which minimize the distance traveled, energy requirement and flying time. In accordance with the approach of dividing a large planning problem into many small problems, the number of planners is however not restricted here in principle to these two and can be extended to further sub-problem-specific planners, which is likely to happen in practice.

(12) Reference sign 25 denotes an approach planner, which is specifically designed for the calculation of approach trajectories. Here, different approach directions to a vertiport (landing site) are precalculated, and may be selected according to the wind and occupancy by other aerial vehicles. Furthermore, reference sign 26 stands for a landing planner, which is specifically designed for the calculation of landing trajectories. As FIG. 2 reveals, the approach planner 25 and the landing planner 26 overlap both with the nominal planning 23 and with the contingency planning 24. This is synonymous to saying that planning modules that cover flight phases across operational states are used over operational states.

(13) Shown at reference sign 27 is an emergency planning, which comprises at reference sign 27a a path planner with an objective function for emergency states.

(14) Finally, reference sign 28 stands for the already mentioned decision logic at mission level, which in the normal case is designed to select on the basis of physical states of the aerial vehicle 1 determined by sensors (compare FIG. 1) and its environment between precalculated trajectory components from the database 2ab (compare FIG. 1) and to put together from them a flight path that is optimum currently under specific criteria.

(15) As already stated further above, in response to an incoming planning request there is initially extensive preplanning, which is transferred to the database in the aerial vehicle and can be used during the flight to reduce the planning problem to a problem of purely deciding on the flight path in the database that is most suitable in each case (decision logic 28). If events or emergency situations that the pre-planned database does not cover occur, this activates an on-line planning algorithm, which, on the basis of the likewise precalculated maneuvers database, restores a safe flying state that is provided in the database by using the maneuvers contained in the maneuvers database (in the form of corresponding control commands) to activate the aerial vehicle, or in particular its drive units, correspondingly.

(16) The algorithm used within the framework of the emergency planning 27 (path planner 27a) is preferably the same that is also used in the contingency case. However, in the contingency case the on-line planner plans within precalculated spaces and only between two pre-planned trajectories. In an emergency, less stringent constraints apply, and the on-line planner is used to calculate at the flying time an emergency landing trajectory to a landing site likewise identified at the flying time. In a possible specific case, the same function call is used in the contingency planner 24b and in the emergency planner 27a.

(17) FIG. 3 shows a macroscopic flow diagram of the mission planning process. Data records concerning the aerial vehicle and its environment are prepared and already provide a database for the planning process before a planning request for a specific mission comes in. Extensive preplanning reduces the computing effort (on board the aerial vehicle) during operational flight.

(18) Reference sign 30 stands for a planning environment, for example a city, and the associated environmental data. Reference sign 31 stands for aerial vehicle parameters or for data concerning the aerial vehicle. The environmental data 30 are collected or stored in an associated database 32, possibly after prior preparation. After corresponding calculation, the aerial vehicle parameters 31 lead to the already repeatedly mentioned maneuvers, which are likewise stored in a database 33. If a planning request 34 then takes place on the basis of corresponding takeoff and destination coordinates 35, the already repeatedly mentioned preplanning takes place at reference sign 36. Subsequently, takeoff 37 takes place, after which the precalculated maneuvers from the database 33 are then also included in the further planning. Reference sign 38 stands for the already mentioned logical selection of trajectories or an additional on-line planning, if required.

(19) Reference to these relationships has already been made in detail further above in the general part of the description.

(20) FIG. 4 illustrates the assignment of the individual planning components on the basis of their execution time within the planning process and describes here in particular the division of the path and mission planning process into on-line and off-line components.

(21) It has already been pointed out that in an extensive pre-calculating phase, on the assumption of an operating environment (for example a metropolitan region) that is largely known and subject to sufficiently slow changing processes, the nominal planning and also large parts of the contingency planning (compare FIG. 2) are already carried out before departure and transferred to an (inspectable and validatable) trajectories database. In parallel, a maneuver library specifically designed for the aerial vehicle and associated maneuver machine are generated and are likewise stored in a database (compare FIG. 3). Both databases are transferred to the aerial vehicle before departure (compare database 2ab in FIG. 1). During the flight, preferably the decision module mentioned in FIG. 2 (decision logic, logic module 28preferably a software function) decides whether there is an emergency requiring intervention of the emergency on-line planning algorithm (reference sign 27 in FIG. 2). If this is not the case, the global path planning problem can be reduced to a logic problem, which selects the most suitable trajectory from the trajectories database (reference sign 38 in FIG. 3). As long as a suitable branching point can be reached, events/conflicts that are not critical to safety are resolved as so-called contingencies, likewise at the logic level, by diverting to a conflict-free trajectory. If a change between pre-planned trajectories is required between branching points, this can be carried out within likewise predefined zones by means of a contingency on-line planner 43.

(22) In FIG. 4, the individual components are as far as possible denoted as they have already been denoted previously, in particular in FIGS. 2 and 3. In this case, in particular the landing site planner mentioned in FIG. 4 may correspond to the already mentioned landing planner 26 (FIG. 2). The already mentioned logic module 28 is also preceded at reference sign 40 by a decision module at mission level, which in turn may also be preceded by an updating of the flight envelope at reference sign 41. Depending on how the decision taken at reference sign 40 turns out, either the logic module 28 or the emergency plan 27 comes into action, wherein the results of the latter act directly on the flight controller 42, i.e. are used for activating the units concerned of the aerial vehicle. The logic module 28 is followed by a contingency on-line planner 43, which accesses the trajectories database 44 and the maneuvers database 33, if required. The logic module 28 or the contingency on-line planner 43 also act directly on the flight controller 42, wherein the logic module 28 also accesses the trajectories database 44. As already mentioned, the trajectories database 44 and the maneuvers database 33 may physically take the form of a common database (compare reference sign 2ab in FIG. 1).

(23) According to FIG. 4, the nominal planner 23 and also the contingency planner 24 according to FIG. 2, along with their subordinate planning modules, are arranged within a so-called horizontal planner 45, which preferably performs the planning of the flight path in a (horizontal) plane perpendicular to the mentioned altitude profile.