A method of communication between embedded systems, produced by a computer program and an associated embedded system.
Patent Information
- Application Number
- FR2023003877
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-04-18
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2043-04-18
Smart Images
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Abstract
Description
Title of the invention: Method for communication between embedded systems, computer program product and associated embedded system
[0001] The present invention relates to a method of communication between a plurality of embedded systems.
[0002] The present invention also relates to an associated computer program product and an associated embedded system.
[0003] More particularly, the present invention relates to communication between embedded systems that are integrated into one or more different platforms, such as aircraft.
[0004] The platform or platforms generally include sensors configured to generate data, such as, for example, data enabling the determination of the positions and velocities of elements detected in airspace. Each onboard system is capable of processing this data.
[0005] To obtain data corresponding to a current situation, it is necessary to exchange data repeatedly between embedded systems. For this purpose, a communication network is generally configured to establish communication links between embedded systems within the same platform, and / or between several distinct platforms.
[0006] Such communication networks are subject to certain constraints. For example, these networks have a limited throughput during communication over a heavily used avionics bus. As another example, the maximum available throughput is variable, particularly in the case of a wireless connection. Other constraints of such communication networks include, for example, temporary interference or a limitation on the amount of data exchanged to ensure the confidentiality of data exchanges.
[0007] Consequently, in some cases, the amount of data exchanged between embedded systems is limited by constraints. This particularly reduces the quality of service of embedded systems, as the systems may, in some cases, only have access to a portion of the data that meets the current requirements.
[0008] One object of the invention is thus to obtain a method of communication between a plurality of embedded systems taking into account constraints of communication between embedded systems, while allowing to obtain a high quality of service.
[0009] To this end, the invention relates to a method of communication between a plurality of embedded systems, each embedded system comprising a memory capable of storing a set of elements each comprising at least one value, each embedded system comprising a communication device configured to exchange data with at least one other embedded system of the plurality of embedded systems,
[0010] the communication process comprising a phase of generating a message by one of the embedded systems, called the transmitting system, at least one element of the set of elements, called the proprietary element, being modifiable only by the transmitting system;
[0011] the memory of the transmitting system storing, for the or each owning element, an internal state comprising an internal instant and an internal value corresponding to the value of the owning element stored by the memory of the transmitting system at the internal instant,
[0012] said memory of the transmitting system further storing, for the proprietary element or elements and for each embedded system other than the transmitting system, referred to as the receiving system, an external state comprising an external instant and an external value corresponding to the value of the proprietary element stored by the memory of the respective receiving system at the external instant,
[0013] the generation phase comprising at least:
[0014] - an extrapolation step comprising an extrapolation of the internal value and the external value of the respective owning element, to obtain extrapolated values;
[0015] - a step of developing, based on extrapolated values, a parameter of classification for the owner(s) and respectively for each receiving system.
[0016] The communication method further includes a step of transmission, by the transmitting system, of the message comprising at least a part of the proprietary element(s) chosen according to each classification parameter.
[0017] According to other advantageous aspects of the invention, the communication method comprises one or more of the following features, taken individually or in all technically possible combinations:
[0018] - the extrapolation step includes, for the proprietary element(s), the extrapolation of the internal value by a predetermined extrapolation function, to obtain a first extrapolated value of the extrapolated values, and the extrapolation step further includes the extrapolation of each external value by said predetermined extrapolation function, to obtain a second extrapolated value of the extrapolated values,
[0019] each ranking parameter being developed based on the first ex- value trapola and the second respective extrapolated value;
[0020] - the memory of the transmitting system stores, for the owner or each owner element, at least one derivative parameter characterizing a time evolution of the value of the respective owning element, an argument of said predetermined extrapolation function being the derivative parameter, preferably an additional argument of said predetermined extrapolation function being a current instant;
[0021] - the development step further includes determining, for the or each proprietary element, of a deviation parameter based on a difference between the first extrapolated value and the second extrapolated value,
[0022] each ranking parameter being developed according to the respective deviation parameter;
[0023] - the development step further includes determining, for the or each proprietary element, of a criticality parameter according to an importance criterion defining the importance of the proprietary element, the importance criterion being chosen from a set of predetermined criteria, and / or according to an operational state of the emitting system from among a plurality of predetermined operational states,
[0024] each classification parameter being developed according to the respective criticality parameter;
[0025] - the value of each element in the element set depends on data in originating from at least one sensor connected to one of the embedded systems;
[0026] - the communication method includes a synchronization phase comprising the transmission step, the synchronization phase further including a step of updating, by the receiving system, a received state of at least one element among the owner element(s) according to the message, the received state including at least one received value, which is the value of the owner element as stored by the memory of the receiving system;
[0027] - the synchronization phase further includes a reception step, by the sending system, of an acknowledgment of receipt as a result of updating the received state according to the message;
[0028] - during the transmission stage, the message and a transmission time are memorized by the transmitting system,
[0029] the communication method further comprising a monitoring step, implemented by the transmitting system, during which:
[0030] if an initial waiting period since the time of transmission is exceeded without receipt of an acknowledgment, the sending system re-sends said message, and / or
[0031] if a second waiting period since the moment of transmission is exceeded in the absence of receipt of the acknowledgment, the transmitting system emits an alarm.
[0032] The invention also relates to a computer program product comprising software instructions which, when implemented by computer equipment, implement the communication process as described above.
[0033] The invention also relates to an embedded system comprising a memory capable of storing a set of elements, each comprising at least one value, the embedded system further comprising a communication device configured to exchange data with at least one other embedded system, referred to as the receiver system, the embedded system being configured to generate a message, at least one element of the set of elements, referred to as the proprietary element, being modifiable only by the embedded system, the memory of the embedded system being configured to store, for the proprietary element(s), an internal state comprising an internal time and an internal value corresponding to the value of the proprietary element stored by the memory of the embedded system at the internal time, said memory of the embedded system being configured to store further, for the proprietary element(s) and for the receiver system(s),an external state comprising an external instant and an external value corresponding to the value of the proprietary element stored in the memory of the respective receiving system at the external instant, the embedded system being configured for: ,
[0034] - extrapolate the internal and external values of the owning element respective, to obtain extrapolated values;
[0035] - to develop, based on the extrapolated values, a ranking parameter for the or each proprietary element and respectively for each receiving system;
[0036] - transmit the message including at least part of the pro- element(s) owner(s) chosen according to each ranking parameter.
[0037] These features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings, in which:
[0038] - [Fig. 1] [Fig. 1] is a schematic view of an assembly comprising several plates each form comprising an embedded system according to the invention;
[0039] - [Fig.2] [Fig.2] is a flowchart of a communication process implemented work by one of the embedded systems or by the embedded systems according to [Fig.1]
[0040] - [Fig.3] [Fig.3] is an example of a part of a system memory embedded, called the transmitting system, among the plurality of embedded systems in [Fig.1], and part of a memory of an embedded system, called the receiving system, other than the transmitting system.
[0041] With reference to [Fig. 1], an assembly 1 comprises at least one platform 2, preferably several platforms 2, each comprising at least one sensor 3 and at less one embedded system 4. For example, set 1 includes at least three platforms 2.
[0042] Each platform 2 is, for example, an aircraft, such as an airplane, a drone, a helicopter, or a blimp. Alternatively, each platform 2 is a satellite, a ship, a submarine, or a land vehicle such as a road or rail vehicle.
[0043] In the example of [Fig.1], each platform 2 comprises a single embedded system 4.
[0044] According to another example, each platform 2 includes several of the embedded systems 4. In particular, each embedded system 4 is embedded in the same platform 2, for example in the same aircraft.
[0045] The term "embedded" and, in particular, "embedded system" means that each embedded system 4 is implemented on board the platform 2. In particular, each embedded system 4 complies with the certification rules of the platform 2. For example, each embedded system 4 has an energy consumption constrained by a maximum consumption dependent on a predefined energy availability within the platform 2. As an example, each embedded system 4 has predefined data processing times, for example, defined by the implementation requirements of the platform 2. Preferably, each embedded system 4 is configured to implement real-time processing.
[0046] Each sensor 3 is a sensor configured to measure data relating to the situation of the platform 2, its environment, or other platforms. For example, each sensor 3 is a sensor chosen from the following list: a location sensor, a pressure sensor, a temperature sensor, an image sensor, such as a radar or lidar image sensor, an audio sensor, a satellite data sensor, a sensor of surrounding platforms, such as a sensor of a Traffic Alert and Collision Avoidance System (TCAS), and a meteorological sensor, such as a sensor including a weather radar.
[0047] Each embedded system 4 is at least partially in the form of an independent computer or is, for example, integrated into a flight management system (or FMS) of the aircraft 2, into an electronic flight bag (or EFB), into an onboard navigation aid computer and / or into any other existing embedded system.
[0048] Each embedded system 4 includes a memory 6, a communication device 8, an acquisition module 10, a processing module 12 and an output module 14.
[0049] According to one example, memory 6 forms a replica of a database. In this In this case, preferably, the database is shared by the 4 embedded systems, in the form of replicas. Thus, for example, the database consists of a plurality of copies or replicas, which are respectively integrated into the 4 embedded systems.
[0050] The database is notably devoid of a centralized database. In particular, the database replicas have an equal hierarchical level with respect to each other. By "equal hierarchical level," it is understood that information in any replica does not take precedence over information in other replicas.
[0051] Each replica includes in particular a copy of the database. Each replica is in particular accessible independently of the other.
[0052] According to another example, memory 6 is a stored array, a list and / or forms a random access memory. In this case, preferably, memory 6 does not form a database.
[0053] Each communication device 8 is configured to implement a data link with each other embedded system 4 of the plurality of embedded systems in order to exchange messages. In particular, each communication device 8 is configured to exchange data, including messages, with the other embedded systems 4.
[0054] The data link is, for example, a wireless link.
[0055] According to an unrepresented variant, the data link is a wired link, such as one or more avionics buses. In this case, preferably, several of the embedded systems 4 are embedded in the same platform 2.
[0056] The acquisition module 10, the processing module 12, and the output module 14 of each embedded system 4 are at least partially in the form of software executable by a processor and stored in the memory of the corresponding computer. The processor is, for example, a microprocessor, in particular of the PowerPC type. In particular, the processor is capable of executing each of the following software components: an acquisition program, a processing program, and an output program.
[0057] Alternatively or in addition, each of the modules 10, 12, 14 is at least partially in the form of a physical device, such as for example a programmable logic circuit, 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 each of the acquisition module 10, the processing module 12 and the output module 14 of each embedded system 4 is implemented in the form of one or more software programs, i.e. in the form of a computer program, also called a computer program product, it is further capable of being stored on a Computer-readable media, not shown, is a medium capable of storing electronic instructions and being connected to a computer system bus. Examples of computer-readable media include optical discs, magneto-optical discs, ROMs, RAM, any type of non-volatile memory (e.g., EPROM, EEPROM, FLASH, NVRAM), magnetic cards, and optical cards. A computer program containing software instructions is then stored on this readable medium.
[0059] The embedded systems 4 are configured, in particular, to be executed in parallel, for example simultaneously. For example, each embedded system 4 is configured to perform processing, in particular by modules 10, 12 and 14, and access its memory 6 independently of the other embedded systems 4.
[0060] Each memory 6 comprises a plurality of elements, each containing at least one value. In particular, each memory 6 comprises the same number and types of elements. For example, when each memory 6 forms a replica of a database, this database comprises the elements. Notably, the state of these elements is shared between the embedded systems.
[0061] Each element preferably includes data from one of the sensors 3. For example, each element includes data from location data, pressure data, temperature data, image data, such as radar or lidar images, audio data, satellite data, data from surrounding platforms, such as data from a TCAS traffic alert and collision avoidance system, and meteorological data, such as data from a weather radar.
[0062] According to one example, the data for each element include one or more radar track(s), one or more position(s), a quantity of fuel, a flying object designation status such as "friendly" or "other", and / or a threat classification status such as "designated", "dangerous" or "uninteresting"
[0063] In particular, the value of each element depends on data from one of the sensors 3, in particular connected to one of the embedded systems 4. For example, the value of each element includes data from one of the sensors 3, or includes processed data obtained by processing data from one of the sensors 3.
[0064] At least one of the elements, preferably several of the elements, is / are modifiable only by one of the embedded systems 4. Such an element is called a "proprietary element" of this embedded system 4 in the remainder of this document.
[0065] In particular, the value of each proprietary element can only be modified by one of the embedded systems 4, in particular according to the data of the sensor 3 of this embedded system 4.
[0066] By "modifiable", it is understood in particular in this description to mean the generation, modification and / or deletion of the value of the element, in particular as a function of data from the sensor 3 of this embedded system 4.
[0067] One of the embedded systems 4 is then specifically authorized to modify each element it owns, namely the owner element, based on a data source associated with the owner element, for example, based on data from the sensor 3 of the platform 2 in which the embedded system 4 is implemented. The embedded systems 4 other than the specifically authorized system are preferably only authorized to update, or refresh, the value of this owner element in their memories 6 based on a message from the specifically authorized embedded system 4.
[0068] A communication method 100 between the embedded systems 4 is now described with reference to Figures 2 and 3.
[0069] The communication method 100 is preferably implemented by embedded systems 4.
[0070] With reference to [Fig. 3], examples of the memory 6 of several of the embedded systems 4 are illustrated. For example, the memory 6 are replicas of a database shared between the embedded systems 4.
[0071] One of the embedded systems 4 is referred to as transmitter system A in this description and is also illustrated in [Fig. 3]. Transmitter system A owns at least one element of the shared database, preferably several elements. These elements are the proprietary elements. One of the proprietary elements of transmitter system A is element El illustrated in [Fig. 3]. In the remainder of this description, the method is described for element El. Those skilled in the art understand that the method applies analogously to the other proprietary elements of transmitter system A, and in particular to a plurality of proprietary elements of transmitter system A.
[0072] The embedded system(s) 4 other than the transmitting system A is / are referred to as the receiving system(s) in this description. The receiving systems are illustrated in [Fig. 3] by the reference numerals PI, P2, P3. In particular, in the example in [Fig. 3], set 1 comprises three receiving systems PI, P2, P3. According to other examples, set 1 comprises N receiving systems, where N is equal to at least 1, for example, equal to 1, 2, 4, or greater than 4.
[0073] The transmitter system A and each receiver system PI, P2, P3 preferably includes the characteristics of the embedded system 4.
[0074] With reference to [Fig. 3], for example during the initialization of the communication process 100, the memory 6 of the transmitting system stores, for the proprietary element El, an internal state S_A comprising an internal instant T_A and an internal value VA_A corresponding to the value of the proprietary element El stored by memory 6 of the sending system at the internal time T_A.
[0075] The memory 6 of the transmitting system A further stores, for the proprietary element El and for each receiving system PI, P2, P3, an external state S_P1, S_P2, S_P3 comprising an external time T_P1 and an external value VA_P1 corresponding to the value of the proprietary element stored by the memory 6 of the respective receiving system PI, P2, P3 at the external time T_P1. For example, the external state S_P1 includes the external value VA_P1 and the external time T_P1.
[0076] Each internal value VA_A and each external value VA_P1 includes the value of the element El, for the given time T_A, T_P1 and for the corresponding system A, PI, P2, P3.
[0077] Each internal instant T_A and each external instant T_P1 defines in particular a temporal instant, including for example a date and a time. According to another example, the temporal instant is defined by a duration of time elapsed since a reference instant.
[0078] According to one example, the transmitting system A further stores, for the owner element El, at least one derivative parameter VAD_A, VAD_P1 characterizing a time evolution of the value of the respective owner element. For example, the internal state S_A includes the derivative parameter VAD_A, and the external state S_P1 includes the derivative parameter VAD_P1, corresponding in particular to the derivative parameter of the element El as stored by memory 6 of the receiving system PI.
[0079] Each derivative parameter is, for example, a derivative of order M, where M is an integer equal to 1, 2, 3 or greater than 3.
[0080] For example, when the value of the owner element is a geographical position of an aircraft, in particular according to a radar track, the derivative parameter VAD_A, VAD_P1 is a speed of the aircraft, or an acceleration of the aircraft.
[0081] According to another example, when the value of the owner element is a classification of an aircraft in a category among predetermined categories, the derivative parameter VAD_A, VAD_P1 is a fixed value, such as 1, corresponding in particular to an indication that the aircraft remains in the same category.
[0082] Preferably, each receiving system PI, P2, P3 stores in its memory 6 a received state S_P1_R for each owner element, such as the element El in the example of [Fig.3].
[0083] The received state S_P1_R consists in particular of data received by the receiving system PI during a previous synchronization between the transmitting system A and the receiving system PL
[0084] The received state S_P1_R preferably includes the same type of data as the state external S_P1. For example, the received state S_P1_R includes a received value VA_P1_R, corresponding in particular to the external value VA_P1, a received time T_P1_R, corresponding in particular to the external time T_P1, and a received derivative parameter VAD_P1_R corresponding in particular to the derivative parameter VAD_P1. In particular, the received value VA_P1_R is the value of the proprietary element El as stored by memory 6 of the receiving system PI.
[0085] Preferably, especially during the initialization of the process, the received state S_P1_R and the external state S_P1 are identical for a given element among the owner element(s).
[0086] The communication method 100 includes a generation phase 102 and a synchronization phase 104.
[0087] The generation phase 102 is preferably implemented at least partially, preferably entirely, by the emitting system A.
[0088] The generation phase 102 includes the generation of a message in particular intended for at least one of the receiver systems PI, P2, P3 for the communication of one of the proprietary elements, such as the element EL. In particular, the receiver system PI, P2, P3 does not own the element EL. In particular, the receiver system PI, P2, P3 is only authorized to update the element El, namely the received state S_P1_R, in its memory 6 according to the message.
[0089] The generation phase 102 includes a detection step 110, an extrapolation step 112, an elaboration step 114, a classification step 116 and a selection step 118.
[0090] During the detection step 110, the transmitting system A detects a sending slot.
[0091] By "sending slot", it is understood in particular as a period of time during which the data link implemented by the communication devices 8 has a capacity for the transmission of the message between the sending system A and at least one of the receiving systems PI, P2, P3.
[0092] The sending slot is detected cyclically, for example at regular and / or predetermined intervals. In other words, for example, the sending slot is defined at regular intervals.
[0093] According to another example, the transmitting system A detects the sending slot based on the available data rate between the transmitting system A and the corresponding receiving system PI, P2, P3, at a given time. For example, when the available data rate is greater than a threshold, the transmitting system A detects the sending slot.
[0094] By "available throughput", it is understood in particular as the capacity of the data link established by the communication devices 8 to transmit a given quantity of digital data per unit of time, at a given instant.
[0095] During the extrapolation step 112, the emitting system A, and in particular the processing module 12 of the emitting system A, extrapolates the internal value VA_A and the external value VA_P1 of the proprietary element El, to obtain extrapolated values.
[0096] For example, the emitting system A extrapolates the internal and external values VA_A, VA_P1 using a predetermined extrapolation function. For example, the emitting system A applies the predetermined extrapolation function to the internal value VA_A to obtain a first extrapolated value, and applies the same predetermined extrapolation function to the external value VA_P1 to obtain a second extrapolated value. The first and second extrapolated values are, in particular, extrapolated to a current time.
[0097] Preferably, the transmitting system A extrapolates the external values VA_P1 for each receiving system PI, P2, P3, and for each proprietary element, by the predetermined extrapolation function.
[0098] When the internal state S_A and the external state S_P1 include the derivative parameter VAD_A, VAD_P1, an argument of the predetermined extrapolation function is preferably the derivative parameter VAD_A, VAD_P1. Another argument is, in particular, a current time. The predetermined function thus uses the derivative parameter VAD_A, VAD_P1 and / or the current time to obtain the corresponding extrapolated value.
[0099] The predetermined extrapolation function defines, for example, a linear extrapolation. For example, the predetermined extrapolation function is defined as follows:
[0100] EA7r(E,T) = Ev + Ev*(T-Er),
[0101] where:
[0102] Extr(E, T) is the extrapolated value of an element E, such as the extrapolated value of the internal value VA_A or the external value VA_P1;
[0103] Ey is the value of the element E, such as the internal value VA_A or the external value VA_P1;
[0104] Ey is the derivative parameter of the element E, such that the derivative parameter VAD_A, VAD_P1;
[0105] T is the current time, and
[0106] Er is a memorization instant of the value Ey in the corresponding memory 6, such as the internal instant T_A or the external instant T_P1.
[0107] According to other examples, the predetermined extrapolation function extrapolates the internal and external values VA_A, VA_P1 by one or more Kalman filters, by at least one Lagrange polynomial, and / or by an algorithm implementing machine learning. According to one example, the predetermined extrapolation function- completed takes into account a history of internal and external values VA_A, VA_P1.
[0108] During the elaboration step 114, the sending system A, and in particular the processing module 12 of the sending system A, elaborates a classification parameter for the proprietary element El and respectively for each receiving system PI, P2, P3, according to the extrapolated values obtained during the extrapolation step 112, in particular according to the first extrapolated value and the second extrapolated value.
[0109] According to one example, the ranking parameter is developed based on a criticality parameter. In particular, development step 114 further includes determining, for element El, the criticality parameter according to an importance criterion defining the importance of the proprietary element El, in particular for one or more of the embedded systems 4.
[0110] The importance criterion is for example chosen from a set of predetermined criteria, corresponding for example to a measure of a danger to one of the on-board systems 4. For example, the importance criterion includes a distance of a flying object, whose position corresponds to the element El, relative to the on-board system 4 and / or includes a speed of approach or departure of the object.
[0111] According to another example or as an optional complement, the importance criterion depends on an operational state of the emitting system among a plurality of predetermined operational states, such as for example a firing phase, or a threat identification phase.
[0112] In particular, the criticality parameter is a relative parameter, defining a relative importance of the element El with respect to the other elements of the set of elements according to the importance criterion.
[0113] The ranking parameter is further elaborated, for example, based on a deviation parameter. For example, elaboration step 114 includes determining the deviation parameter for element El based on a deviation or difference between the first extrapolated value and the second extrapolated value.
[0114] For example, the deviation parameter is determined by a deviation function.
[0115] The slack function defines, for example, a normalized linear difference between the first extrapolated value and the second extrapolated value. For example, the slack function is defined as follows:
[0116] A Ç P t\ ab.^ExtriS_A, T)-Extr(.ST)}, ma^Extr(s_^ T) Ext^P, T)')
[0117] where:
[0118] EcExtr is the deviation parameter depending on the states S_A and S_P and the current time T;
[0119] Extr is the extrapolated value of the state S_A or S_P of the element El, in particular the extrapolated value of the internal value VA_A or the external value VA_P1;
[0120] abs defines an absolute value;
[0121] max dé defines a maximum value.
[0122] According to another example, the slack function is defined as follows, with the predefined variables: [°123] EcExdS A, S
[0124] According to another example, the slack function is defined as follows, with the predefined variables:
[0125] EcExtr(S_A, S_P, T) = ïogJabs(Extr(S_A, T)-Extr(S_P, T) ))•
[0126] The gap function is chosen for example according to a type of data included in the element El.
[0127] According to one example, the emitting system A implements a ranking function to obtain the ranking parameter based on the extrapolated values. The ranking function is, for example, defined as follows:
[0128] Class(S_A, S_P, T) = Crit(S_A, T^EcExt^S _A, S_P, T),
[0129] where:
[0130] Class is the classification parameter dependent on the element El with the states S_A and S_P and the current time T, where S_P is one of the states S_P1, S_P2, S_P3;
[0131] Crit is the criticality parameter depending on the state S_A and the current time T, where S_P is one of the states S_P1, S_P2, S_P3;
[0132] EcExtr is the deviation parameter depending on the states S_A and S_P and the current time T.
[0133] According to one variant, the ranking parameter depends only on one of the extrapolated values, the criticality parameter and the deviation parameter.
[0134] During the sorting step 116, the issuing system A sorts each owner element, such as element El, according to the sorting parameter. In particular, the issuing system A determines a list comprising the owner elements sorted according to the value of the sorting parameter, with the highest value of the sorting parameter at the top of the list.
[0135] During selection step 118, the sending system A selects the proprietary element(s) with the highest value of the ranking parameter for transmission to the receiving systems P1, P2, and P3. The number of proprietary elements selected depends in particular on the available bandwidth during the detected sending window. For example, the sending system A selects the proprietary elements in the order of the list determined during ranking step 116, until a maximum message size is reached, depending in particular on the available bandwidth during the detected sending window.
[0136] The sending system A generates the message comprising the selected proprietary element(s), in particular the internal state S_A of each selected proprietary element. Preferably, the sending system A further defines the receiving system(s) PI, P2, P3 and a message identifier, and integrates into the message an indication of this or these receiving system(s) PI, P2, P3 and the identifier.
[0137] The synchronization phase 104 includes a transmission step 120, a refresh step 121, a response step 122, a reception step 124, a replacement step 126 and a monitoring step 128.
[0138] During transmission step 120, the transmitting system A transmits the message comprising at least a portion of the owner(s) selected according to each classification parameter. In particular, the transmitting system A transmits the message comprising the internal state S_A of each selected owner(s), and optionally the identifier and the receiving system PI, P2, P3 forming the message recipient. Specifically, the transmitting system A transmits the message via the data link formed by the communication devices 8, such as a wireless link or a wired link, such as one or more avionics buses.
[0139] According to one example, the transmitting system A stores, during the transmission step 120, the message and a time of transmission, in particular with regard to use during the replacement 126 and / or monitoring 128 steps.
[0140] During update step 121, the receiving system PI, P2, P3 updates the received state S_P1_R of the owner element El according to the message. The received state S_P1_R includes at least the received value VA_P1_R.
[0141] In particular, during the update step 121, the receiving system PI, P2, P3 receives the message and replaces the received state S_P1_R stored in its memory 6 with the internal state S_A contained in the message for the element concerned. For example, with reference to [Fig. 3], the receiving system PI replaces the received state S_P1_R of the element El with the state S_A. This allows, in particular, the memory 6 of the receiving system PI to be updated with the state S_A.
[0142] During response step 122, the receiving system PI, P2, P3 issues an acknowledgment as a result of updating the received state S_P1_R, in particular via the data link.
[0143] During the reception step 124, the transmitting system A receives the acknowledgment from the receiving system PI, P2, P3. This informs the transmitting system A in particular of the update of the received state S_P1_R in the memory 6 of the receiving system PI, P2, P3.
[0144] During the replacement step 126, the transmitting system A replaces the external state S_P1, S_P2, S_P3 stored in the memory 6 of the transmitting system A according to the message transmitted during the transmission step 120. For example, when the transmitting system During the transmission step 120, A memorizes the sending of the internal state S_A by the message, the sending system A replaces the external state concerned S_P1, S_P2, S_P3 with the internal state S_A as sent by the message.
[0145] During an example, the replacement step 126, the sending system A deletes the memorization of the transmitted message, in particular as a result of the replacement.
[0146] During the monitoring step 128, the transmitting system A monitors waiting periods since the message was sent, in particular to check whether the receiving system PI, P2, P3 updates its memory 6 according to the message.
[0147] For example, if a first waiting period since the moment of transmission, memorized during the transmission step 120, is exceeded in the absence of a receipt of the acknowledgment, the sending system transmits the message again.
[0148] The first waiting period is, for example, predetermined, notably to detect a loss of the message or a loss of the acknowledgment. The first waiting period depends, for example, on the transmission time of the message and / or the acknowledgment.
[0149] For example, if a second waiting period since the time of transmission is exceeded in the absence of receipt of the acknowledgment, the transmitting system A emits an alarm.
[0150] The second waiting period is for example predetermined so as to detect an interruption of communication between the transmitting system A and the receiving system PI, P2, P3.
[0151] Preferably, the first waiting period is of a different duration compared to the second waiting period.
[0152] Preferably, the monitoring step 128 is repeated cyclically.
[0153] With reference to [Fig. 2], the steps implemented by the transmitting system A are shown on the left, and the steps implemented by the receiving system PI are shown on the right. For example, the transmitting system A implements all the steps of the generation phase 102, as well as the transmission step 120, and optionally the reception step 124, the replacement step 126, and / or the monitoring step 128. The receiving system PI preferably implements the update step 121 and the response step 122.
[0154] The communication method 100 is preferably implemented by consecutive iterations, each iteration being defined by the respective sending slot.
[0155] According to one example, the communication method 100 further includes a modification step, not shown, of the internal state S_A of the proprietary element(s), in particular based on the data from the sensor(s) 3 of the transmitting system A. Preferably, the modification step is implemented periodically, for example, each time new data is generated by the sensor(s). 3. In particular, the modification step is implemented independently of a sending slot detection for sending the message. Specifically, the modification step is implemented at a higher repetition frequency than the generation phase.
[0156] According to one example, the communication method 100 includes the temporary or permanent deactivation of the response step 122 and the reception step 124. In particular, the sending and receiving of the acknowledgment is deactivated in this case. This makes it possible, for example, to increase the bandwidth available for transmitting the message(s).
[0157] It is understood that the communication process 100 has a large number of advantages.
[0158] In particular, the communication method 100 makes it possible to obtain a high quality of service, because among all the proprietary elements, the method transmits the message with the proprietary elements that bring the greatest added value to the embedded systems 4, expressed in particular in the form of the ranking parameter. For example, when the extrapolated values indicate a large difference from the internal or external value of an element, this proprietary element is likely to present a greater added value than other elements in certain cases.For example, when the proprietary element relates to the position of a flying object to be tracked, and an extrapolated position is very different from the position according to the internal or external value, this indicates that the flying object has a high speed, and in certain situations an update of the memory 6 of the PI, P2, P3 receiver system with this element is of great interest, i.e. a great added value, for the PI, P2, P3 receiver system.
[0159] According to examples, the ranking parameter depends on the gap parameter and / or the criticality parameter for each proprietary element, which makes it possible to characterize very precisely the added value brought by each element to the embedded systems 4, for example according to a type of element.
[0160] By transmitting a message containing at least some of the proprietary elements selected according to each classification parameter, the process takes into account the added value in the form of the classification parameter. Also, because the message includes, for example, only some of the proprietary elements, and because this part is chosen according to the classification parameters, the process can adapt to the available bandwidth.
[0161] According to one example of the process, and by way of illustration, selecting the proprietary elements that have the highest value of the ranking parameter makes it possible to "fill" the available throughput with these elements. As a result, a maximum number of proprietary elements are transmitted, and these elements present at total maximum added value for embedded systems 4. Thus, the overall knowledge for all embedded systems 4 is maximized.
[0162] When the memories 6 form replicas of a database, for example in the event of a loss or malfunction of a platform 2 or an embedded system 4, the communication method 100 ensures the continued operation of the other platforms 2 or embedded systems 4 thanks to the shared database, with each embedded system 4 comprising a replica of this database. In particular, the method and the embedded systems 4 with the replicas exhibit high resilience in the event of a loss or malfunction of one of the platforms 2.
Claims
Claims
1. Communication method (100) between a plurality of embedded systems (4), each embedded system (4) comprising a memory (6) capable of storing a set of elements each comprising at least one value, each embedded system (4) comprising a communication device (8) configured to exchange data with at least one other embedded system of the plurality of embedded systems (4), the communication method (100) comprising a generation phase (102) of a message by one of the embedded systems (4), called the sending system, at least one element of the set of elements, called the proprietary element (El), being modifiable only by the sending system;the memory (6) of the transmitter system storing, for the or each proprietary element (El), an internal state (S_A) comprising an internal instant (T_A) and an internal value (VA_A) corresponding to the value of the proprietary element (El) stored by the memory (6) of the transmitter system at the internal instant (T_A), said memory (6) of the transmitter system further storing, for the or each proprietary element (El) and for each embedded system (4) other than the transmitter system, called the receiver system, an external state (S_P1, S_P2, S_P3) comprising an external instant (T_P1) and an external value (VA_P1) corresponding to the value of the proprietary element (El) stored by the memory (6) of the respective receiver system at the external instant (T_P1), the generation phase (102) comprising at least:; - an extrapolation step (112) comprising an extrapolation of the internal value (VA_A) and the external value (VA_P1) of the respective proprietary element (El), to obtain extrapolated values; - a step of developing (114), as a function of the extrapolated values, a classification parameter for the or each proprietary element (El) and respectively for each receiving system; the communication method (100) further comprising a step of transmission (120), by the transmitting system, of the message comprising at least part of the proprietary element(s) (El) chosen as a function of each classification parameter.
2. A communication method (100) according to claim 1, wherein the extrapolation step (112) comprises, for the or each pro- owner (El), extrapolating the internal value (VA_A) by a predetermined extrapolation function, to obtain a first extrapolated value of the extrapolated values, and the extrapolation step (112) further comprises extrapolating each external value (VA_P1) by said predetermined extrapolation function, to obtain a second extrapolated value of the extrapolated values, each ranking parameter being developed as a function of the first extrapolated value and the respective second extrapolated value.
3. Communication method (100) according to claim 2, wherein the memory (6) of the transmitting system stores, for the or each proprietary element (El), at least one derivative parameter (VAD_A, VAD_P1) characterizing a temporal evolution of the value of the respective proprietary element (El), an argument of said predetermined extrapolation function being the derivative parameter (VAD_A, VAD_P1), preferably an additional argument of said predetermined extrapolation function being a current instant.
4. A communication method (100) according to claim 2 or 3, wherein the developing step (114) further comprises determining, for the or each proprietary element (El), a deviation parameter as a function of a deviation between the first extrapolated value and the second extrapolated value, each classification parameter being developed as a function of the respective deviation parameter.
5. Communication method (100) according to any one of the preceding claims, in which the developing step (114) further comprises determining, for the or each proprietary element (El), a criticality parameter according to an importance criterion defining an importance of the proprietary element (El), the importance criterion being chosen from a set of predetermined criteria, and / or as a function of an operational state of the transmitting system from among a plurality of predetermined operational states, each classification parameter being developed as a function of the respective criticality parameter.
6. Communication method (100) according to any one of the preceding claims, wherein the value of each element of the set of elements depends on data from at least one sensor (3) connected to one of the on-board systems (4).
7. A communication method (100) according to any one of the claims- preceding indications, comprising a synchronization phase (104) comprising the transmission step (120), the synchronization phase (104) further comprising a step of updating (121), by the receiving system, a received state (S_P1_R) of at least one element among the owner element(s) (El) as a function of the message, the received state (S_P1_R) comprising at least one received value (VA_P1_R), which is the value of the owner element (El) as stored by the memory (6) of the receiving system.
8. Communication method (100) according to claim 7, wherein the synchronization phase (104) further comprises a step of receiving (124), by the transmitting system, an acknowledgment of receipt following the updating of the received state (S_P1_R) according to the message.
9. Communication method (100) according to any one of claims 1 to 7, wherein, during the transmission step (120), the message and a transmission time are stored by the transmitting system, the communication method (100) further comprising a monitoring step (128), implemented by the transmitting system, during which: if a first waiting period from the transmission time is exceeded in the absence of reception of an acknowledgment of receipt, the transmitting system transmits said message again, and / or if a second waiting period from the transmission time is exceeded in the absence of reception of the acknowledgment of receipt, the transmitting system emits an alarm.
10. Computer program product comprising software instructions which, when implemented by computer equipment, implement a communication method according to any one of the preceding claims.
11. Embedded system (4) comprising a memory (6) capable of storing a set of elements each comprising at least one value, the embedded system (4) further comprising a communication device (8) configured to exchange data with at least one other embedded system, called the receiving system, the embedded system (4) being configured to generate a message, at least one element of the set of elements, called the proprietary element (El), being modifiable only by the embedded system (4), the memory (6) of the embedded system (4) being configured to store, for the or each proprietary element (El), an internal state (S_A) comprising an internal instant (T_A) and an internal value (VA_A) corresponding to the value of the proprietary element (El) stored by the memory (6) of the embedded system (4) at the internal instant (T_A), said memory (6) of the embedded system (4) being configured to further store, for the or each proprietary element (El) and for the or each receiving system, an external state (S_P1, S_P2, S_P3) comprising an external instant (T_P1) and an external value (VA_P1) corresponding to the value of the proprietary element (El) stored by the memory (6) of the respective receiving system at the external instant (T_P1), the embedded system (4) being configured to: - extrapolate the internal value (VA_A) and the external value (VA_P1) of the respective proprietary element (El), to obtain extrapolated values; - develop, based on the extrapolated values, a classification parameter for the or each proprietary element (EI) and respectively for each receiving system; - send the message including at least part of the proprietary element(s) (El) chosen according to each classification parameter.