Aircraft-mounted data recorder, aircraft, recording method and associated computer program

Abstract

Aircraft-mounted data recorder, aircraft, recording method, and associated computer program. The present invention relates to a data recorder (12) (D) suitable for installation on board an aircraft (10), the recorder (12) comprising: an acquisition module configured to acquire a set of recording parameter(s), a detection module configured to detect at least one event of interest related to the aircraft (10), via at least one model of the aircraft, a recording module configured to record data (D) received by the recorder into a storage memory according to the set of recording parameter(s), the recording module being connected to the acquisition module and the detection module, the detection module being configured to modify the set of recording parameter(s) according to the at least one detected event of interest. Figure for the abstract: Figure 1

Description

Title of the invention: Aircraft-mounted data recorder, aircraft, recording method and associated computer program

[0001] The present invention relates to a data recorder suitable for being carried on board an aircraft.

[0002] The invention also relates to an aircraft comprising such a recorder.

[0003] The invention also relates to a method for recording data put into work by such a recorder.

[0004] The invention also relates to a computer program comprising software instructions which, when executed by a computer, implement such a recording method.

[0005] The invention then relates to the field of systems embedded on board aircraft, and particularly to electronic data recording devices intended to be embedded on board aircraft, especially commercial aviation.

[0006] As is known per se, an aircraft is equipped with a plurality of onboard systems, enabling the capture of raw data, for example anemometric data, from outside or inside the aircraft. This data then needs to be analyzed, processed and recorded, in order to be reused, in particular by airlines to carry out, for example, aircraft maintenance or safety operations.

[0007] Currently, there are two ways to record this raw data. One known solution is to use a data recorder on board the aircraft. Data recorders, such as Quick Access Recorders (QARs) or Flight Operations and Maintenance Exchange (FOMAX) recorders, record the raw data according to recording configurations that characterize how the raw data is recorded. Generally, the recording configurations are fixed, using configuration files that predetermine the parameters of the data to be recorded. More recently, US patent 10,580,230 B2 describes a recorder whose configuration can vary depending on the phase of flight.

[0008] A second solution for recording raw data is to use ground / aircraft connectivity, in particular for communicating an aircraft maintenance need, via ACARS (Aircraft Communication Addressing and Reporting System).

[0009] However, such recorders are not suitable for detecting certain malfunctions, particularly those not mentioned in the recorder's configuration file. These recorders are not capable of recording high-frequency data. Furthermore, the configuration of these recorders is not customizable, meaning that airlines cannot tailor the recording to their needs, for example, by modifying the recording parameters based on the aircraft's tail number or according to their own maintenance procedures. In addition, ground-to-air connectivity recording has the disadvantage of being very expensive.

[0010] The aim of the invention is therefore to provide a data recorder, intended to be carried on board an aircraft, allowing for more efficient recording of data from the systems on board the aircraft, while limiting the consumption of computer resources.

[0011] To this end, the invention relates to a data recorder, suitable for being carried on board an aircraft, the recorder comprising:

[0012] - an acquisition module configured to acquire a set of parameter(s) registration,

[0013] - a detection module configured to detect at least one event of interest relating to the aircraft, via at least one model of the aircraft,

[0014] - a recording module configured to record data received by the recorder, in a storage memory and according to the set of recording parameter(s), the recording module being connected to the acquisition module and the detection module,

[0015] the detection module being further configured to modify the set of recording parameter(s) according to at least one event of interest detected.

[0016] With the data recorder according to the invention, thanks to the detection module which modifies the set of recording parameters if an event of interest is detected, data recording is dynamic, meaning that the way in which data is recorded varies over time, depending on the type of event(s) occurring on board the aircraft or in its vicinity. Furthermore, since recording is driven by event detection, only relevant data is recorded, which is more efficient and notably limits the consumption of computing resources.

[0017] An event of interest is understood to mean a malfunction of the aircraft, or any event relating to the performance, maintenance, or safety of at least one piece of equipment on board the aircraft. For example, abnormal engine heating or a suspicious propeller vibration pattern are two events of interest.

[0018] According to other advantageous aspects of the invention, the recorder comprises one or more of the following features, taken individually or in all technically possible combinations:

[0019] - the set of recording parameter(s) includes at least one parameter chosen from the group including: an identifier of a received data frame, a data recording frequency, and a data retention period in storage memory;

[0020] - the acquisition module is configured to acquire a plurality of sets of recording parameter(s), and the recording module is configured to record the data received by the recorder, in storage memory and according to said plurality of sets of recording parameter(s), for recording data relating to several detected events of interest;

[0021] - each event of interest is chosen from among an aircraft malfunction and an event relating to at least one piece of equipment on board the aircraft; the event relating to at least one piece of equipment on board being chosen from the group comprising: an event relating to the performance of at least one piece of equipment on board, an event relating to the safety of at least one piece of equipment on board and an event relating to the maintenance of at least one piece of equipment on board;

[0022] - a model of the aircraft is a model of at least one piece of equipment on board of the aircraft;

[0023] - a model of at least one embedded device is configured to characterize the evolution over time of at least one input and / or output parameter of at least one on-board equipment;

[0024] said model being preferably included in the detection module;

[0025] said model being preferably calculated by a machine learning algorithm included in the detection module;

[0026] - the detection module is configured to detect a respective event of interest relating to a corresponding on-board equipment, when input and / or output data of said on-board equipment obtained via the model of said on-board equipment show a discrepancy with the input and / or output data received for said on-board equipment;

[0027] - The processing module is configured to generate an event report relating to at least one on-board equipment if an event of interest relating to at least one on-board equipment is detected, said event report including the input and / or output data of said on-board equipment obtained via the model of said on-board equipment and the input and / or output data received for said on-board equipment.

[0028] The invention also relates to an aircraft comprising a recorder as defined above.

[0029] The invention also relates to a data recording method, implemented by a recorder suitable for being carried on board an aircraft and comprising at least the following steps:

[0030] - acquisition of a set of recording parameter(s);

[0031] - detection of at least one event of interest relating to the aircraft, via at least one aircraft model;

[0032] - recording of data received by the recorder, in a memory of storage and according to the set of recording parameters,

[0033] the set of recording parameter(s) being modified according to at least one event of interest detected during the detection step.

[0034] The invention also relates to a computer program comprising software instructions which, when executed by a computer, implement a recording method as defined above.

[0035] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0036] [Fig-1] [Fig.1] is a schematic view of an aircraft comprising a recorder according to the invention, the recorder being connected to an external system operated by an airline;

[0037] [Fig.2] [Fig.2] is a schematic view of the data from the aircraft's on-board equipment;

[0038] [Fig.3] [Fig.3] is a schematic view of the operation of the recorder according to the invention;

[0039] [Fig.4] [Fig.4] is a flowchart of a data recording method according to the invention, the method being implemented by the recorder of [Fig.1].

[0040] In [Fig.1], an aircraft 10 includes a recorder 12 connected to on-board equipment 14 of the aircraft 10, via data buses 15, the on-board equipment 14 being visible in [Fig.2].

[0041] The aircraft 10 is preferably an airplane, in particular a commercial airplane, such as a long-haul aircraft. The aircraft 10 is capable of carrying passengers, not shown, in particular several dozen passengers, or even several hundred passengers. Alternatively, the aircraft 10 is a helicopter, or even a remotely piloted drone.

[0042] The recorder 12 is also connected via an edge-to-ground connection 16 to an external system 18. The edge-to-ground connection 16 is, for example, achieved by a Satcom (Satellite Communication) satellite connection, or a Air-to-ground connection (ATG), or gate connectivity.

[0043] The onboard equipment 14 includes critical aircraft systems 10, such as avionics systems 21, engines 22, and utility systems 23, as seen in [Fig. 2]. The onboard equipment 14 also includes cargo systems 24 and cabin systems 25. The onboard equipment 14 typically consists of assemblies of sensors, actuators, digital or electronic devices, and software, implementing a particular function of the aircraft 10.

[0044] Avionics systems 21 include, for example:

[0045] - one or more automatic navigation and guidance systems, such as a system inertial navigation or INS (from the English Inertial Navigation System), a satellite positioning system or GNSS (from the English Global Navigation Satellite System), for example GPS (from the English Global Positioning System), Galileo, BeiDou, a flight management system or FMS (from the English Flight Management System), an inertial reference system or 1RS (from the English Inertial Reference System), an instrument landing system or ILS (from the English Instrument Landing System);

[0046] - one or more ground, traffic and weather radar monitoring systems, such as a enhanced ground proximity warning system or EGPWS (from the English Enhanced Ground Proximity Warning System), an air collision avoidance system or TCAS (from the English Traffic Collision Avoidance System), a weather radar or WX Radar (from the English Weather Radar), an automatic dependent surveillance-broadcast system or ADS-B (from the English Automatic Dependent Surveillance-Broadcast), a terrain awareness and warning system or TAWS (from the English Terrain Awareness and Warning System);

[0047] -one or more communication systems, such as a VHF (Very High Frequency Communication System) communication system, a digital messaging system or ACARS (Aircraft Communications Addressing and Reporting System), a high frequency or HF (High Frequency Communication System) communication system, a satellite communication system or SATCOM (Satellite Communication System), a data communication system between the air traffic controller and the pilot, also called CPDLC (Controller Pilot Data Link Communications); and

[0048] - one or more dashboard systems, such as an instrument system electronic flight instrument systems (EFIS) comprising a primary flight display (PFD) and a navigation display or ND (Navigation Display), engine indication and crew alerting system or EICAS (Engine Indication and Crew Alerting System), a multi-function display showing various information such as navigation, radar, or weather, also called MFD (Multi-Function Display), and a flight control panel allowing the pilot to enter autopilot parameters, such as altitude and speed, also called FCP (Flight Control Panel).

[0049] Utility systems 23 include, for example, a braking system and an aircraft air conditioning system.

[0050] The data buses 15 connect the recorder 12 to the various on-board equipment 14. The data buses 15, or avionics buses, implement a transmission of data D, called input and / or output data, from the on-board equipment 15, to the recorder 12.

[0051] The recorder 12 is configured to retrieve, for example, data from the engines and the APU (Auxiliary Power Unit).

[0052] The external system 18 is operated by an airline 20. The external system 18 is typically adapted to implement various functions 19, particularly those within the purview of the airline 20, such as, for example, a maintenance function, an operations control center (OCC) function, a safety management system (SMS) function, or a fatigue risk management system (FRMS) function.

[0053] The recorder 12 is for example also connected to an entertainment system 26, or IFE (In-Flight Entertainment), and to Wi-Fi access points, such as a cockpit Wi-Fi access point 27, a cabin Wi-Fi access point 28 and a cargo Wi-Fi access point 29, via a central connection 30, in order to collect data D emitted by equipment contained in the aircraft 10, such as for example the mobile phones and tablets of the passengers or crew on board.

[0054] The recorder 12 comprises an acquisition module 32, a detection module 34, and a recording module 36, connected to the acquisition module 32 and the detection module 34, as shown in [Fig. 3]. Optionally, the recorder 12 includes a processing module 38.

[0055] In the example of [Fig.3], the recorder 12 includes an information processing unit 40 formed for example of a memory 42 and a processor 44 associated with the memory 42. The recorder 12 also includes a storage memory 46.

[0056] In the example of [Fig. 3], the acquisition module 32, the detection module 34, and the recording module 36, as well as, optionally, the module The processing functions 38 are each implemented as a software program, or a software component, executable by the processor 44. The memory 42 is then capable of storing acquisition software, detection software, and recording software, as well as, optionally, processing software. The processor 44 is then capable of executing each of these programs: acquisition software, detection software, and recording software, as well as, optionally, processing software.

[0057] In an alternative not shown, the acquisition module 32, the detection module 34 and the recording module 36, as well as the optional processing module 38, are each implemented in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array), or in the form of a dedicated integrated circuit, such as an ASIC (Application Specified Integrated Circuit).

[0058] When the recorder 12 is implemented in the form of one or more software programs, i.e., in the form of a computer program, it is also capable of being recorded on a computer-readable medium (not shown). A computer-readable medium is, for example, a medium capable of storing electronic instructions and being connected to a bus of a computer system. For example, a readable medium is an optical disc, a magneto-optical disc, a ROM, a RAM, any type of non-volatile memory (e.g., FLASH or NVRAM), or a magnetic card. A computer program comprising software instructions is then stored on the readable medium.

[0059] The acquisition module 32 is configured to acquire at least one set 33 of recording parameter(s), typically through communication - via ground / aircraft connectivity 16 - with an external platform, such as the external system 18. The external platform is, for example, operated by the airline's maintenance function 20.

[0060] The set 33 of recording parameter(s) includes, for example, at least one identifier of a data frame from the data bus 15, a data recording frequency and a data retention time in the storage memory 46.

[0061] The detection module 34 is configured to detect at least one event of interest relating to the aircraft 10, via at least one model of the aircraft.

[0062] The aircraft model is a dataset characterizing the evolution over time of at least one input and / or output parameter of at least one of the aircraft's onboard equipment 14 10. For example, a data table listing the temperature of the engines 22, recorded every 5 minutes by a temperature sensor integrated into the engines 22, during the first hour of one of the flights aircraft 10's anterior model, is a temperature model of aircraft 10's engines 22.

[0063] An event of interest is a malfunction of the aircraft 10 or an event relating to the safety, maintenance or performance of at least one of the on-board equipment 14 of the aircraft 10. For example, abnormal heating of the engines 22, or cabin depressurization detected by a pressure sensor integrated into the cabin systems 25, are events of interest relating respectively to the engines 22 and the cabin systems 25.

[0064] The detection module 34 includes a plurality of models of the aircraft 10, relating to all the on-board equipment 14 of the aircraft 10. Models of the aircraft 10 are included in the detection module 34 prior to the flight of the aircraft 10. Optionally, one or more new models of the aircraft 10 are also included in the detection module 34 during the flight of the aircraft 10 by the airline 20, via the ground / aircraft connectivity 16. As a further optional feature, one or more models of the aircraft 10 included in the detection module 34 are updated or deleted by the airline 20, via the ground / aircraft connectivity 16.

[0065] The detection module 34 further includes a machine learning algorithm, configured to learn the normal operation of all the on-board equipment 14 of the aircraft 10. The normal operation of the aircraft 10 is established on the basis of recordings made during previous flights of the aircraft 10. This machine learning algorithm thus makes it possible to supplement the knowledge of the detection module 34 provided by the models of the aircraft 10, and thus makes it possible to detect events of interest that would be undetectable by the models included in the detection module 34 alone. Indeed, if, for example, the data emitted by one of the on-board equipment 14 shows that the corresponding on-board equipment 14 is outside its normal operating range, while no fault has been detected, the detection model 34 will detect an event of interest, for example of the suspicious equipment type.

[0066] The detection module 34 is further configured to perform a modification M of the set 33 of recording parameters if an event of interest relating to the aircraft 10 is detected. Indeed, if, for example, an event of interest relating to one of the on-board devices 14 is detected, the modification M consists, for example, of recording all the data from said on-board device 14, at the highest possible recording frequency.

[0067] The recording module 36 is configured to record, in the storage memory 46 and according to the set 33 of recording parameters, the data D from the on-board equipment 14 via the data buses 15.

[0068] For example, if the detection module 34 detects abnormal heating of the motors 22, the detection module 34 modifies the set 33 of recording parameter(s) included in the recording module 36.

[0069] The recording module 36 then records the temperature data of the motors 22, included in the frame, with identifier entered in the modified set 33 of recording parameters, of the data bus 15, at the frequency entered in the modified set 33 of recording parameter(s), in the storage memory 46 for the duration entered in the modified set 33 of recording parameter(s).

[0070] The processing module 38 is configured to generate an event report R if an event of interest relating to the aircraft 10 is detected. The processing module 38 is further configured to communicate the event report R, via the ground / aircraft connectivity 16, to the competent function 19 implemented by the external system 18.

[0071] The event report R includes the input and / or output data of at least one onboard equipment 14 considered by the event of interest, and the input and / or output data of at least one model relating to the at least one onboard equipment considered by the event of interest. Optionally, the event report R also includes a specific recipient of the report and an associated level of urgency. For example, if the detection module 34 detects abnormal heating of the motors 22, the processing module 38 generates the event report R including the temperature of the motors 22 recorded by the recording module 36, and the temperature of the motors 22 described by one of the models included in the detection module 34.As an optional supplement, the event report R also indicates that the airline's maintenance function 20 must be informed of this event of interest, and that the level of urgency related to the intervention is critical, if the difference between the recorded temperature and the temperature described by the model is very significant.

[0072] The operation of the recorder 12 will now be explained, in particular with the help of [Fig.4] representing a flowchart of the data recording process D according to the invention, the process being implemented by the recorder 12.

[0073] Prior to this, a plurality of models of the aircraft 10, relating to all the on-board equipment 14 of the aircraft 10, have been included in the detection module 34, for example by the external system 18. These models typically include functions or modeling laws enabling the modeling of the expected output values ​​as a function of the recorded input values, for all the on-board equipment 14 of the aircraft 10.

[0074] During an acquisition step 100, the recorder 12 acquires, via its acquisition module 32, the set 33 of recording parameter(s) coming from, by For example, from the external system 18, via the ground / ship connectivity 16. This set 33 of recording parameter(s) takes, for example, the form of a configuration file, comprising at least one identifier for a data bus frame 15, a data recording frequency for each frame, and a data recording duration for each frame. The acquisition module 32 then communicates this set 33 of recording parameter(s) to the recording module 36, for data recording according to said set 33.

[0075] The detection module 34 of the recorder 12 performs a detection step 110, after the acquisition step 100 or more generally repeated regularly in parallel with the other steps. During the detection step 110, the detection module 34 detects an event of interest relating to the aircraft 10 when at least one input and / or output data point of at least one of the onboard equipment 14 differs from the same input and / or output data point of at least one model of that same onboard equipment, and when said difference is greater than a predefined threshold. This at least one model is at least one of the models included in the detection module 34. Alternatively, this at least one model is one of the models of the aircraft 10, developed by the machine learning algorithm included in the detection module 34.Following the detection of an event of interest, the detection module 34 then modifies the set 33 of recording parameter(s) included in the recording module 36. For example, if the detection module 34 detects a discrepancy between the model data relating to the speed of aircraft 10 and the data recorded in the storage memory 48, the detection module 34 detects an event of interest relating to the speed sensors of aircraft 10, and modifies the set 33 of recording parameter(s) included in the recording module 36. The detection module 34 requests, for example, more frequent recording of the speed data in order to clarify the discrepancy between the actual data and the model data, and requests a longer recording of the speed data in order to verify whether this discrepancy between the actual speed and the expected speed is temporary or permanent.Advantageously, the detection module 34 also requires a temperature recording of the speed sensors, in order to verify, among other things, whether the probes are functional.

[0076] The recording module 36 then records in the storage memory 46, during recording step 120, the data D according to the set 33 of recording parameter(s) modified by the detection module 34 during step 110, said data D including in particular the input and / or output data of at least one on-board device considered by the event of interest. The detection module 34 thus repeats detection step 110 again, if it detects a new event of interest thanks to this new recorded data in storage memory 46. For example, during acquisition step 100, the external system 18 communicates to the acquisition module 32 a set 33 of recording parameters including: the identifier of the data bus frame 14 connected to the aircraft speed sensor 10, a recording frequency of the aircraft speed of 10 Hz, and a retention time of five seconds in storage memory 48. The recording module 36 then reads, during recording step 120, the data contained on the data bus frame 15, with corresponding identifier, 10 times during each second, records each set of data read in storage memory 48, and deletes each set of data from storage memory 48 five seconds after its recording in storage memory 48.

[0077] The processing module 38 then generates, during a processing step 130, the event report R for each event of interest detected by the detection module 34. The event report R includes the model data contained in the detection module 34 that enabled the detection of the event of interest during step 110, and the data recorded by the recording module 36 in the storage memory 46 during step 120. Optionally, the event report R also includes a recipient of the report R, which is, for example, one of the functions 19 of the airline 20 implemented by the external system 18, as well as an urgency level associated with the event of interest. Once generated by the processing module 38, the event report R is sent to the external system 18 via the ground / aircraft connectivity 16.

[0078] Thus, the operation of the recorder 12, such that the set 33 of recording parameter(s) is dynamically modified by the detection module 34, and in particular when an event of interest is detected, allows first of all a recording of the data D exclusively carried out on board the aircraft 10. Since the hardware and computer resources are limited, said operation makes it possible to concentrate the recording of the data D, and therefore of the computer resources (memory space and recording frequency) on the relevant data enabling the detection of an event of interest, and to minimize the computer resources allocated to the recording of non-essential data.

[0079] Furthermore, the detection module 34 allows for the detection of events of interest customized according to the type of aircraft 10 (the models being included by the airline operators 20, they are therefore customizable according to the types of on-board equipment 14, and the habits and procedures specific to the airline 20). The detection module 34 also allows for the detection of events of interest that were previously undetectable with current data recording devices, thanks in particular to the customization of the models according to the aircraft type included in the detection module 34 and the machine learning algorithm included in the detection module 34, which dynamically models the operation of aircraft 10.

[0080] Furthermore, the detection module 34 and the recording module 36 of the recorder 12 are at least partially remotely controllable, via the ground / aircraft connectivity 16, by the external system 18, and in particular by the operators of the airline 20. Advantageously, the set 33 of recording parameter(s) is also remotely modifiable by the external system 18. The generation of event reports R by the processing module 38 also makes it possible to inform, remotely and in real time, the external system 18 of any event of interest that has occurred on board the aircraft 10. Consequently, the recorder 12 according to the invention does not require any operational intervention (which reduces operational costs) on the aircraft 10, when the aircraft 10 is on the ground, by the airline 20, for example to unload data from the storage memory 46, or to modify the set 33 of recording parameter(s).

Claims

Demands

1. Data recorder (12) (D), suitable for being carried on board an aircraft (10), the recorder (12) comprising: - an acquisition module (32) configured to acquire a set (33) of recording parameter(s), - a detection module (34) configured to detect at least one event of interest relating to the aircraft (10), via at least one model of the aircraft, - a recording module (36) configured to record data (D) received by the recorder, in a storage memory (46) and according to the set (33) of recording parameter(s), the recording module (36) being connected to the acquisition module (32) and to the detection module (34), characterized in that the detection module (34) is configured to modify the set (33) of recording parameter(s) according to the at least one event of interest detected.

2. Recorder (12) according to claim 1, wherein the set (33) of recording parameter(s) comprises at least one parameter selected from the group comprising: an identifier of a received data frame, a data recording frequency, and a data retention time in the storage memory (46).

3. Recorder (12) according to claim 1 or 2, wherein the acquisition module (32) is further configured to acquire a plurality of sets (33) of recording parameter(s), and the recording module (36) is configured to record the data (D) received by the recorder, in the storage memory (46) and according to said plurality of sets (33) of recording parameter(s), for the recording of data relating to several detected events of interest.

4. A recorder (12) according to any one of the preceding claims, wherein each event of interest is selected from an aircraft malfunction (10) and an event relating to at least one piece of equipment on board the aircraft (10); the event relating to the at least one piece of equipment on board being chosen from the group comprising: an event relating to the performance of at least one on-board equipment, an event relating to the safety of at least one on-board equipment and an event relating to the maintenance of at least one on-board equipment.

5. Recorder (12) according to any one of the preceding claims, wherein a model of the aircraft is a model of at least one piece of equipment on board the aircraft.

6. Recorder (12) according to claim 5, wherein the model of at least one on-board equipment is configured to characterize the evolution over time of at least one input and / or output parameter of at least one on-board equipment; said model preferably being included in the detection module (34); said model preferably being calculated by a machine learning algorithm included in the detection module (34).

7. Recorder (12) according to claim 6, wherein the detection module (34) is configured to detect a respective event of interest relating to a corresponding on-board equipment, when input and / or output data of said on-board equipment obtained via the model of said on-board equipment differ from the input and / or output data received for said on-board equipment.

8. Recorder (12) according to claim 7, wherein the recorder (12) further comprises a processing module (38) configured to process an event report (R) relating to at least one on-board equipment if an event of interest relating to at least one on-board equipment is detected, said event report including the input and / or output data of said on-board equipment obtained via the model of said on-board equipment and the input and / or output data received for said on-board equipment.

9. Aircraft (10) comprising a data recorder (12), characterized in that the recorder (12) is according to any one of the preceding claims.

10. A data recording method, implemented by a recorder (12) suitable for installation on board an aircraft and comprising at least the following steps:

11. - acquisition (100) of a set (33) of recording parameter(s); - detection (110) of at least one event of interest relating to the aircraft (10), via at least one model of the aircraft; - recording (120) of the data received by the recorder (12), in a storage memory (46) and according to the set (33) of recording parameter(s), characterized in that, during the detection step (110), the set (33) of recording parameter(s) is modified according to at least one event of interest detected. Computer program comprising software instructions which, when executed by a computer, implement a method according to the preceding claim.