System and method for obtaining diagnostic data from a motor vehicle

Abstract

The invention proposes a method for transmitting diagnostic data from a vehicle between a user terminal and a removable communication module connected to an ODB2 type diagnostic port.The method comprises the steps: emission (102) of presence beacons by the removable communication module, also called a "dongle"; reception (104) of a presence beacon; sending (110) of a pairing request by the user terminal; said pairing request comprising identification data; reception (112) of the pairing request by the module; recording (114) of the terminal identifier in the removable communication module; prohibition (116) of recording of identification data of a foreign user terminal in the removable communication module, so that said user terminal (32) then constitutes an exclusive user terminal associated with the removable communication module; and transmission (120) of diagnostic data by the removable communication module to the exclusive user terminal. Figure to be published with the abstract: Figure 2.

Description

Title of the invention: System and method for obtaining diagnostic data from a motor vehicle

[0001] The invention relates to monitoring data of a motor vehicle. More specifically, the invention relates to the recovery of diagnostic data of a motor vehicle. The subject of the invention is a method for transmitting diagnostic data of a motor vehicle. The invention also provides a system for transmitting diagnostic data of a motor vehicle. The invention also provides a removable communication module for transmitting diagnostic data of a motor vehicle.

[0002] During its operation, a vehicle generates various operating data. Operating data includes specific events and operating parameters. Operating parameters include engine temperature, exhaust line clogging rate, fuel injection pressures, driving hours, energy consumption and many other physical quantities and measurements. Operating data is used to evaluate the operating conditions of a vehicle, and predict the probability of a possible breakdown or maintenance requirement at a given time horizon. Thus, collecting operating data is useful for maintaining the reliability of the vehicle's components.

[0003] Operating data is commonly measured by on-board sensors and processors. It is collected by a control network, designated by the acronym CAN, which corresponds to the English expression "Controller Area Network". Some are then stored on board in a memory integral with the vehicle. The operating data is then collected via a monitoring module which is connected to the vehicle. The latter has a connection socket, or port, such as a connector designated by the acronym ODB, which corresponds to the English expression "On-Board Diagnostic". A second-generation device, ODB2, is commonly deployed in current vehicles. The OBD2 on-board diagnostic device offers a diagnostic solution for engine failures.

[0004] Document KR20040066966A discloses a method and system for managing vehicle operation information by remote monitoring via Bluetooth® to reduce the costs required for managing vehicle operation information using wireless LAN communication based on a Bluetooth® type communication protocol. A Bluetooth® dongle includes a flash memory, a Bluetooth® module, a connector, a processor (central processing unit) and two backup capacitors; and is connected to an OBD (On-Board Diagnosis) system integrated in a vehicle via a connector. The memory stores faults not obtained via all kinds of sensors integrated into the OBD system. In the event that a vehicle is within a service area of ​​a hotspot with an access point, the Bluetooth® module allows the vehicle to perform wireless LAN communication via Bluetooth® via an antenna.

[0005] Document US2007296559A1 discloses a system and method for controlling a portable communication device in a vehicle. The portable communication device is controlled by a protection or workload management module. To control the cellular phone, at least one transmitter is coupled to the diagnostic connector (e.g., an OBD-II connector) in the vehicle, which is coupled directly to the connector forming a receiver via a device commonly referred to as a "dongle." The transmitter receives instructions from the workload manager module and transmits them to the cellular phone, preferably via a short-range wireless protocol such as Bluetooth®. In order for the cellular phone to properly interpret and act on these commands, an application program (e.g., a Java applet) is preferably downloaded to the phone by any suitable means.With the application program in place in the phone, commands from the workload management module or other control module in the vehicle can now be implemented on the cell phone, providing a safety and convenience advantage to the vehicle user.

[0006] In particular, document US2007296559A1 describes a vehicle comprising an on-board diagnostic port. A removable communication module with a “dongle” type housing is connected to the on-board port and communicates via Bluetooth® with a mobile phone. The on-board port communicates with vehicle sensors, and with a satellite geopositioning system.

[0007] However, each data transmission step exposes the vehicle user to communication leaks. The operating data contains data considered confidential, the dissemination of which the user wishes to control. Indeed, the removable communication module is likely to send information received and used by another communication terminal.

[0008] In addition, there is a risk that the transmitted operating data may not be correctly collected. Data may partially reach the reference terminal, or arrive in the form of a damaged file. As a result, maintenance operations are carried out on biased or partial operating data. Thus, the safety of the vehicle is not maintained at a satisfactory level. Likewise, engine settings information may be based on erroneous data.

[0009] The invention aims to address at least one of the problems or drawbacks encountered in the prior art. In particular, the invention aims to improve the security of exchanges via a removable communication module. The invention also aims to optimize the security, speed, and quality of transmission of diagnostic data from a motor vehicle.

[0010] According to a first aspect, a method for transmitting diagnostic data of a motor vehicle between a user terminal and a removable communication module connected to a diagnostic port of the motor vehicle; remarkable in that the transmission method comprises the following steps: transmission of presence beacons by the removable communication module; reception of one of the presence beacons by the user terminal; sending of a pairing request by the user terminal; said pairing request comprising identification data of said user terminal; reception of the pairing request by the removable communication module; at least partial recording of the identification data in the removable communication module;then prohibiting the recording of identification data of a foreign user terminal in the removable communication module, so that said user terminal then constitutes an exclusive user terminal associated with the removable communication module; transmitting diagnostic data by the removable communication module to the exclusive user terminal. ;

[0011] The invention allows the selection of an exclusive user terminal and then prohibits the recording of another user terminal. The removable communication module ignores or limits its interactions with any other user terminal. Thus, the removable communication module begins transmission only when it is certain of the presence of the previously selected exclusive user terminal.

[0012] Preferably, following the registration step, the method includes a step of stopping the emission of presence tags.

[0013] Preferably, in the recording step, said identification data are recorded in a non-volatile memory of the removable communication module.

[0014] Preferably, the removable communication module comprises a recorded unlocking key; in the step of sending a pairing request by the user terminal; said pairing request comprises a transmitted unlocking key; and the method further comprises a step of comparing the transmitted unlocking key with the recorded unlocking key; then provided that the transmitted unlocking key corresponds to the recorded unlocking key, the method carries out the recording step.

[0015] Preferably, following the reception step; the method further comprises a step of defining a time variable key in the user terminal identification data.

[0016] Preferably, at the transmission step, the diagnostic data are encrypted according to said time-variable key.

[0017] Preferably, in the definition step, the time-variable key is calculated as a function of a time data item; and in the recording step, the time-variable key is recorded in the removable communication module.

[0018] Preferably, the identification data comprises a terminal identifier of the user terminal; in the definition step the time variable key is calculated as a function of the module identifier and the terminal identifier of the user terminal.

[0019] Preferably, from the data transmission step, the method comprises a step of iterative measurement of signal power by the removable communication module; then a step of comparing the signal power with a disconnection criterion; then a step of disconnecting the removable communication module from the exclusive user terminal when the signal power reaches the disconnection criterion.

[0020] Preferably, in the step of receiving the pairing request, the method comprises a step of initial measurement of a reference power of the pairing request by the removable communication module; the disconnection criterion is a function of the reference power.

[0021] Preferably, the disconnection criterion is at most 30% of the reference power, more preferably at most 50% of the reference power.

[0022] Preferably, the method further comprises: a step of receiving a subsequent terminal identifier of a subsequent user terminal; a step of comparing the subsequent terminal identifier with an exclusive terminal identifier of the exclusive user terminal; the method repeating the step of transmitting diagnostic data by the removable communication module provided that the subsequent terminal identifier corresponds to the exclusive terminal identifier.

[0023] Preferably, when the subsequent terminal identifier differs from the exclusive terminal identifier, the method comprises a step of erasing identification data by the removable communication module.

[0024] Preferably, in the step of sending a pairing request, the signal power of the pairing request is constant for a duration threshold, and / or the signal power of the pairing request is greater than or equal to a second power threshold.

[0025] Preferably, before the step of transmitting the presence beacons, the method comprises the following steps: starting a data transmission application on the user terminal; searching for a removable communication module by the user terminal; identification of a removable communication module by the user terminal.

[0026] Preferably, the disconnection step is a request blocking step.

[0027] Preferably, the diagnostic data comprises event data, and in particular data from the live data display, i.e. operating parameters and values.

[0028] Preferably, when the issued unlocking key differs from the recorded unlocking key, the method comprises blocking transmissions by the user terminal and the removable communication module.

[0029] Preferably, the time data is time data defining the time variable key or a date of receipt of the at least one presence beacon.

[0030] Preferably, the communication protocol is a short-distance communication protocol.

[0031] Preferably, the method comprises a step of inserting the removable communication module into a communication port of the motor vehicle.

[0032] Preferably, at the transmission step, the presence beacons comprise an encrypted removable communication module identifier.

[0033] Preferably, the step of defining a time-variable key is carried out after the recording step; and / or the time-variable key is defined by the removable communication module.

[0034] Preferably, following the transmission step, the method comprises a step of receiving the diagnostic data by the user terminal, then optionally a step of confirming receipt of said diagnostic data.

[0035] Preferably, the terminal identifier is a unique terminal identifier.

[0036] Preferably, the disconnection criterion is a signal strength criterion.

[0037] Preferably, in the recording step, the terminal identifier is recorded in a flash memory of the removable communication module.

[0038] Preferably, at the transmission step, the user terminal is in the motor vehicle.

[0039] Preferably, at the transmission stage, the motor vehicle is moving.

[0040] Preferably, at the transmission step, the diagnostic data are encrypted.

[0041] Preferably, after the disconnection step and / or before the diagnostic data transmission step, the method comprises the steps of: • detecting a subsequent user terminal; • communication of a subsequent user identifier; • comparison of the subsequent user ID to the terminal ID uti exclusive reader; • pairing of the removable communication module and the exclusive user terminal if the subsequent user identifier matches the exclusive user terminal identifier.

[0042] Preferably, the method further comprises a step of decrypting the vehicle diagnostic data by the user terminal.

[0043] Preferably, the step of sending the pairing request and the transmission step comprise the use of a communication protocol with a range of at most 10 meters, preferably at most 5 meters.

[0044] Preferably, in the transmission step, the pairing power level is greater than or equal to a second power level threshold.

[0045] Preferably, after the transmission step, the method comprises a step of erasing transmitted diagnostic data.

[0046] Preferably, in the step of sending the pairing request, the user terminal is at a first distance from the removable communication module, and in the transmission step, the user terminal is at a second distance from the removable communication module; the second distance being at most five times greater than the first distance.

[0047] Preferably, the method comprises a step of acquiring monitoring data from the motor vehicle, then a step of converting the acquisition data into diagnostic data.

[0048] According to another aspect, the invention proposes a method for transmitting diagnostic data of a motor vehicle between a user terminal and a removable communication module connected to a diagnostic port of the motor vehicle; the removable communication module having a recorded unlocking key and the user terminal comprising a terminal identifier; remarkable in that the transmission method comprises the following steps: transmission of presence beacons by the removable communication module; reception of one of the presence beacons by the user terminal; sending of a pairing request by the user terminal; said pairing request comprising a transmitted unlocking key and the terminal identifier of said user terminal; reception of the pairing request by the removable communication module; comparison of the transmitted unlocking key with the recorded unlocking key;then, provided that the issued unlocking key matches the registered unlocking key, registering the terminal identifier in the removable communication module; and transmitting diagnostic data by the removable communication module to the user terminal.

[0049] According to another aspect, the invention provides a system for transmitting operating data of a motor vehicle; the transmission system comprising a user terminal, and a removable communication module intended to be connected to a diagnostic port of the motor vehicle; the removable communication module storing a registered unlocking key and the user terminal comprising a terminal identifier; remarkable in that the transmission system is adapted for: • emit presence beacons with the removable communication module; • receive one of the presence beacons by the user terminal; • send a pairing request by the user terminal; said pairing request comprising an issued unlocking key and the terminal identifier of said user terminal; • receive the pairing request via the removable communication module; • compare the issued unlocking key with the registered unlocking key; then, provided that the issued unlocking key matches the registered unlocking key: • record the terminal identifier in the removable communication module; and • transmit diagnostic data via the removable communication module to the user terminal.

[0050] Preferably, the user terminal is an exclusive user terminal.

[0051] According to another aspect, the invention proposes a computer program comprising instructions which, when the program is executed by a computer, cause the latter to implement a method for transmitting diagnostic data of a motor vehicle between an exclusive user terminal and a removable communication module connected to a diagnostic port of the motor vehicle; the removable communication module having a module identifier; remarkable in that the transmission method comprises the following steps: emission of presence beacons by the removable communication module; reception of a pairing request by the removable communication module; said pairing request comprising identification data of said exclusive user terminal; at least partial recording of the identification data of the exclusive user terminal in the removable communication module;and prohibition of recording identification data of a foreign user terminal in the removable communication module; transmission of diagnostic data by the removable communication module to the exclusive user terminal.

[0052] According to another aspect, the invention proposes a removable communication module for a system for transmitting operating data from a motor vehicle to an exclusive user terminal comprising identification data, said removable communication module being intended to be connected to an on-board diagnostic port. of a motor vehicle; characterized in that said removable communication module is configured to: emit presence beacons; receive a pairing request from an exclusive user terminal; said pairing request comprising identification data of said exclusive user terminal; prohibit recording of identification data of a foreign user terminal in the removable communication module; record at least partially the identification data; and transmit diagnostic data to the exclusive user terminal.

[0053] According to another aspect, the invention proposes a motor vehicle comprising a removable communication module and / or a transmission system remarkable in that the communication module is in accordance with the invention and / or the transmission system is in accordance with the invention.

[0054] Preferably, the vehicle comprises first diagnostic data and second diagnostic data; the second data comprising positioning data and / or time data; in the transmission step only the first diagnostic data being transmitted.

[0055] Thus, the invention protects confidential data since the sensitive data does not pass through the communication module.

[0056] The invention will be well understood and other aspects and advantages will appear clearly on reading the description which follows, given with reference to the figures appended and listed below.

[0057] [Fig.l] is a side view of a motor vehicle with a transmission system according to the invention.

[0058] [Fig.2] is a diagram of a transmission method according to the invention.

[0059] [Fig.3] is a diagram of a communication protocol according to the invention.

[0060] In the following description, the term "comprise" is synonymous with "include" and is not limiting in that it allows the presence of other elements in the motor vehicle, the transmission system or other steps in the method to which it relates. It is understood that the term "comprise" includes the terms "consist of".

[0061] Diagnostic data means data comprising codes relating to anomalies or specific events detected during the operation of the motor vehicle. The diagnostic data comprises codes corresponding to measurements exhibiting a variation relative to a reference threshold.

[0062] In the present description, the ranges of values ​​include the limits which delimit them.

[0063] Throughout the description, the different figures use the same reference signs to designate identical or similar entities.

[0064] [Fig.l] represents a motor vehicle 10 according to the invention. The vehicle at car 10 comprises energy storage means 12 and at least one motor 14 adapted to drive said motor vehicle 10.

[0065] The motor vehicle 10 comprises at least one sensor 16, preferably a plurality of sensors 16. The sensors 16 make it possible to measure physical quantities, such as operating data of the motor vehicle 10. The sensors 16 are adapted to measure temperatures of the energy storage means 12 and of the engine 14, a charge level of the energy storage means 12, a pressure of the engine 14. The sensors can measure temperature and / or pressure data of a heat exchanger system (not shown), a steering system, a suspension system, a braking system. This list is not exhaustive.

[0066] Generally, at least one or each sensor 16 is configured to provide physical data of a mobile and / or actuatable entity of the motor vehicle 10.

[0067] The operating data may include time data, such as operating times. It may include data on one or more operating states of safety devices. For example, it may include diagnostic data on the operating state of an airbag system (not shown), commonly referred to as an "airbag".

[0068] The motor vehicle 10 further comprises a local communication network (not shown). The local communication network can at least connect the sensors 16.

[0069] The motor vehicle 10 comprises an on-board computer 20 with an on-board memory and a calculator. The memory of the on-board computer 20 is capable of storing the operating data of the motor vehicle 10 as they are sent by the sensors 16. The calculator can perform calculations on the operating data and generate diagnostic data by performing logical tests on the measured operating data. The diagnostic data is recorded on the on-board memory.

[0070] The motor vehicle 10 also comprises a port, forming a connection socket. The port may be an external port. It may be a peripheral. The port is an on-board diagnostic port 22. The on-board diagnostic port 22 is connected to the on-board computer 20; directly or via the local communication network. Thus, the on-board diagnostic port 22 provides access to the operating data stored in the on-board memory.

[0071] The motor vehicle 10 is equipped with a transmission system 24. The transmission system 24 is capable of transmitting data from the motor vehicle; for example, diagnostic data from the motor vehicle 10. The transmission system 24 may include the on-board diagnostic port 22.

[0072] The transmission system 24 has a removable communication module 30. The removable communication module 30 comprises a housing housing an external memory and an external processor (not shown). The removable communication module 30 is connected to the on-board diagnostic port 22.

[0073] The on-board diagnostic port 22 and / or the removable communication module 30 are configured to send requests to the on-board memory in order to obtain diagnostic data. The transmission system 24 accommodates a user terminal 32. The user terminal 32 may be of the touch tablet type, or of the cellular telephone type; also called a “smartphone”. The user terminal 32 may be a smart portable device. It may be a portable computer; in particular in that it includes its own power supply. The user terminal 32 includes a visual interface, an interface for manual data entry by a user, a terminal memory, and a terminal processor (not shown). The terminal processor and the terminal memory may form a computer, for example a terminal computer.

[0074] The terminal processor may include one or more programmable electronic microprocessors or microcontrollers. In addition, the terminal processor may include a central processing unit (CPU), dedicated memory (in addition to or as the terminal memory), and an input / output (I / O) interface through which the terminal processor may receive a plurality of input signals. Such an I / O interface is also configured to generate a plurality of output signals including, but not limited to, those used to control and / or provide diagnostic data to the on-board diagnostic port 22 or other systems of the motor vehicle 10.

[0075] The terminal memory is provided for storing data and instructions or code (i.e., computer software comprising code instructions) readable and / or writable by the terminal processor. The terminal memory may include various forms of non-volatile (i.e., non-transitory) memory. The non-volatile memory includes flash or read-only memory (ROM), any type of programmable read-only memory (e.g., PROM, EPROM, EEPROM). The terminal memory optionally includes volatile memory, including random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), and synchronous dynamic random access memory (SDRAM). According to the invention, the terminal memory may be internal to the terminal processor, or alternatively form a separate component.

[0076] The user terminal 32 communicates with the removable communication module according to a short-range wireless communication protocol; for example of the Bluetooth® type. The Bluetooth® protocol is a telecommunications protocol for the short-distance bidirectional exchange of data using radio waves. The Bluetooth® protocol uses a frequency band between 2400 MHz and 2483.5 MHz. Several communication channels are defined in this frequency band. In the context of the invention, the choice of the Bluetooth® protocol limits interference due to the narrowness of its frequency band. Furthermore, its power level limits its range in order to limit the potential receivers formed by one or more user terminals. The metal structure of the motor vehicle tends to limit the range outside the passenger compartment. Thus, the invention secures data transmission in that it reduces the number of potential recipients.

[0077] Generally, the communication protocol is a short-distance communication protocol, preferably with a range of at most 20 meters, more preferably at most 10 meters; possibly at most 5 meters.

[0078] [Fig.2] shows a diagram of a method for transmitting operating data of a motor vehicle according to the invention. The motor vehicle may correspond to that shown in relation to [Fig.l].

[0079] The transmission method comprises the following steps, notably executed in the following order: • insertion 100 of the removable communication module into a communication port of the vehicle; • emission 102 of presence beacons by the removable communication module, said removable communication module comprising a recorded unlocking key; • reception 104 of one of the presence beacons by the user terminal; • initial measurement 106 of a reference power of the pairing request by the removable communication module; • definition 108 of a time variable key which is calculated based on time data in the identification data of the user terminal; • sending 110 of a pairing request by the user terminal; said pairing request comprising the identification data and an unlocking key sent by said user terminal, and therefore its time variable key; • reception 112 of the pairing request by the removable communication module; • comparison 113 of the issued unlocking key with the registered unlocking key; then provided that the issued unlocking key corresponds to the registered unlocking key, • recording 114 of identification data in the removable communication module, and in particular of the time variable key; • prohibition 116 of recording identification data of a foreign user terminal in the removable communication module, so that said user terminal then constitutes an exclusive user terminal associated with the removable communication module; • stop 118 of the emission of presence beacons; • transmission 120 of diagnostic data by the removable communication module to the exclusive user terminal; • reception 122 of diagnostic data by the exclusive user terminal; • iterative measurement 124 of signal power by the removable communication module; then • comparison 126 of the measured signal power with respect to a disconnection criterion; then • disconnection 128 of the removable communication module to the exclusive user terminal when the signal strength reaches the disconnection criterion; • receipt 130 of a subsequent terminal identifier from a subsequent user terminal; • comparison 132 of the subsequent terminal identifier with the identification data; • pairing 134 of the removable communication module and the subsequent user terminal if the subsequent terminal identifier corresponds to the identification data, and resumption or start of the transmission step 120 of diagnostic data by the removable communication module provided that the subsequent terminal identifier corresponds to the identification data; • decryption 136 of vehicle diagnostic data by the user terminal.

[0080] The user terminal is said to be an exclusive user terminal in the sense that it is the only one that can pair with the communication module. It is the first user terminal to successfully pair with the removable communication module. Its identification data is exclusive identification data. It includes its terminal identifier which is a unique identifier, specific to each terminal.

[0081] Generally, the steps of the transmission method use a short-distance communication protocol, for example a Bluetooth® protocol. The short-distance communication protocol is understood as a protocol whose range is at most 20 meters, preferably at most 10 meters. Beyond these distances, the power of the received signal involves losses of information, for example of at least 10%.

[0082] At the insertion step 100, the communication module is powered. It is powered following the vehicle being switched on. In particular, its external processor and its communication means are powered. The communication means comprise an antenna capable of operating in transmission and reception.

[0083] In the transmission step 102, the presence beacons are encrypted; and in the reception step 104 of one of the presence beacons, the user terminal decodes said presence beacon. The presence beacons comprise a signature, or module identifier, making it possible to identify the removable communication module. The signature makes it possible to detect that the removable communication module is part of the transmission system. This detection is carried out through the application installed on the user terminal. The presence beacons are transmitted at regular intervals, for a predetermined duration from the switching on or the insertion step 100.

[0084] In the transmission step 102, the presence beacons comprise an encrypted removable communication module identifier. This identifier is decrypted by the application executed by the user terminal. This prevents a terminal not equipped with the dedicated application from being able to identify or recognize the removable communication module. Confidentiality is thus prioritized.

[0085] Before the step 102 of transmitting the presence beacons, the transmission method may comprise the following steps (not shown), and carried out by the user terminal: starting a data transmission application on the user terminal; searching for a removable communication module by the user terminal; identifying the removable communication module by the user terminal. The step of identifying the removable communication module is triggered by the reception of one of the presence beacons. Generally speaking, the step of starting the application may be a step of sending a declaration of ready-to-pair state. The reception of the presence beacons allows a change of state of the removable communication module; which goes from a standby state to a reactivation state.

[0086] Before the step 102 of transmitting the presence beacons, the method comprises a step of acquiring monitoring data from the motor vehicle, then a step of converting the monitoring data into diagnostic data. The step of acquiring monitoring data may be a step of reading the monitoring data. The acquisition step makes it possible to obtain continuously or at regular intervals physical quantities specific to the operation of the motor vehicle. Then, during the conversion step, these physical quantities are compared to tolerance thresholds in order to identify possible anomalies, and therefore to carry out a real-time diagnosis of the vehicle. These anomalies are advantageously translated by predefined designations; which are in turn encrypted. They form data of diagnostics. More generally, diagnostic data can include event-related data. Communicating diagnostic data indirectly reduces the weight of messages sent while optimizing diagnostic accuracy and communication time. Decoding time is also reduced.

[0087] The initial measurement step 106 is carried out from, or after, the step 112 of receiving the pairing request. The disconnection criterion is a function of the reference power. The disconnection criterion; and therefore of communication cut-off; is at most 30% of the reference power, preferably at most 50% of the reference power. The disconnection criterion is also understood as a power criterion. This power level requires proximity to the user terminal, and in particular a presence in the passenger compartment. This limits the number of terminals likely to enter into communication with the removable communication module.

[0088] In the step 108 of defining the time-variable key, this is defined by the user terminal which then becomes exclusive. The time-variable key comprises an AES key; corresponding to the acronym for the English expression “Advanced Encryption Standard”. The time-variable key is integrated into the identification data of the exclusive user terminal. The AES key is advantageously an AES 256 key, which optimizes security and calculations. According to one option, in the transmission step 120, the diagnostic data are encrypted according to said time-variable key.

[0089] In the definition step 108, the time-variable key is calculated based on a time data item that comes from the internal clock of the exclusive user terminal. The time data item may correspond to the date of definition of the time-variable key, or the date of reception of the at least one presence beacon. In this alternative, the date is the date of the step 106 of reception of the beacon which allows the procedure to continue. By date, we mean a point in time defined to the nearest minute, preferably to the nearest second, more preferably to the nearest tenth of a second. The time data item is applied to a time function, for example an elliptic function, providing a time code.

[0090] The identification data specific to the exclusive user terminal includes its exclusive terminal identifier. They form a recorded unlocking key. In the definition step 108 the time-variable key is calculated based on the module identifier and the terminal identifier of the exclusive user terminal. The time-variable key is calculated by multiplying the identifiers with the time code. Other operations are possible to further increase security.

[0091] The invention therefore combines temporal data which selects a point on a curve following a temporal law, codes it according to a mathematical function, then combines with the terminal identifier and the module identifier. Thus, there is uniqueness of the data allowing pairing since they are based on the identities of the paired entities, of a temporal data encoded by a security function. Thus, security is reinforced.

[0092] In the step 110 of sending a pairing request, the power of the signal of the pairing request is constant for a duration threshold, and / or the power of the signal of the pairing request is greater than or equal to a second power threshold. This aspect adds security because it avoids accidental connections.

[0093] The pairing request may comprise a query message with a request to initiate pairing between the user terminal and the removable communication module; and further comprises the unlocking code of the transmission system.

[0094] In the step 110 of sending the pairing request, the user terminal is at a first distance from the removable communication module, and in the transmission step, the user terminal is at a second distance from the removable communication module; the second distance being at most five times greater than the first distance.

[0095] The step 112 of receiving the pairing request, or the step 114 of recording the identification data, may comprise a sub-step of confirming the pairing, for example with sending a confirmation message from the removable communication module to the exclusive user terminal.

[0096] The comparison step 113 of the unlocking key issued with the recorded unlocking key is carried out by the removable communication module. This aspect increases security since a single device centralizes the key steps. In addition, this optional intermediate step adds a level of security since it requires a first verification code to be able to continue the rest of the method. If, at the end of the comparison, the unlocking key issued differs from the recorded unlocking key, the method continues the execution of the step of sending (102) a presence beacon by the removable communication module.

[0097] At the terminal identifier recording step 114, the terminal identifier is recorded on the non-volatile memory of the removable communication module. The terminal identifier is recorded in the flash memory of the removable communication module. Thus, this terminal identifier remains even in case of power-off of the removable communication module.

[0098] At the prohibition step 116, the removable communication module blocks the consideration of a foreign user terminal. The option to consider a new user terminal is removed. The data specific to the latter is not retained after reception. The removable communication module closes the sensitivity of recording all other identification data.

[0099] Generally, the prohibition step may be a step of erasing data of a foreign user terminal.

[0100] In the transmission step 120, the diagnostic data is encrypted according to said time-variable key, which is recorded on both sides of the transmission system. This key is then used to encode and decode the exchanged information.

[0101] Following the data transmission step 120, when the subsequent terminal identifier differs from the identification data specific to the exclusive user terminal, at the end of the comparison step 132; the terminal present is a user terminal foreign to the system. According to one option, the method then executes a step 138 of erasing the terminal identifier considered foreign by the removable communication module. The method therefore performs a locking of the possibility of pairing with a user terminal.

[0102] In the transmission step 120, the exclusive user terminal is in the motor vehicle. Thus, the user terminal is able to receive this data when the motor vehicle is moving. It can receive and decode it. Ultimately, the user is able to interpret the diagnostic data, and only he is capable of doing so since he has the compatible identification data. He is the only one likely to enter into communication with the communication module. Security is reinforced.

[0103] In the transmission step 120, the pairing power level is greater than or equal to a second predefined power level threshold. If the pairing power level is less than a second threshold, it is considered that the exclusive user terminal is not close enough to the communication module; and that a security criterion is no longer met. From then on, the method returns to the step 102 of transmitting presence beacons.

[0104] In the iterative signal power measurement step 124, the removable communication module can measure signal powers of requests for transmission of diagnostic data and / or signal powers of confirmation of receipt of diagnostic data. According to an alternative of the invention, the iterative signal power measurement step is carried out by the user terminal; for example on the frames of the sending of diagnostic data.

[0105] Following the step 138 of erasing the terminal identifier by the removable communication module when the subsequent terminal identifier differs from the identification data; the method restarts its execution at the step 102 of transmitting the presence beacons.

[0106] In the signal power comparison step 126, as long as the signal power does not reach the disconnection criterion, the method continues the step of 120 transmission of diagnostic data.

[0107] [Fig. 3] shows a diagram of a protocol for transmitting diagnostic data of a motor vehicle according to the invention. The motor vehicle may correspond to that presented in relation to [Fig. 1]. The transmission protocol may be integrated into the transmission method presented in relation to [Fig. 2].

[0108] Horizontal arrows between the two dotted rails indicate signals sent between the removable communication module 30 and the user terminal 32. The direction of the arrowhead indicates the direction of travel of the signal. A possible foreign user terminal 34 is shown. Its architecture is similar to that of the user terminal 32; however, their identifiers differ.

[0109] The transmission protocol includes the following steps: • emission 102 of presence beacons at regular intervals; for example when the vehicle is switched on, in particular for a predefined period; • reception 104 of one of the presence beacons; • definition 108 of a time variable key; • sending 110 of a pairing request; said pairing request comprising a sent unlocking key and identification data of the terminal identifier; • reception 112 of the pairing request; • comparison 113 of the issued unlocking key with the registered unlocking key; then, provided that the issued unlocking key matches the registered unlocking key: • recording 114 of the terminal identifier in the removable communication module; • prohibition 116 of recording identification data of a foreign user terminal so that said user terminal 32 then constitutes an exclusive user terminal associated with the removable communication module 30; and • transmission 120 of diagnostic data to the exclusive user terminal; • confirmation 140 of receipt of diagnostic data; • disconnection 128 of the exclusive user terminal 32; • sending 142 of a pairing request by a foreign user terminal 34 with its identifier; • deletion 138 of the identifier of the foreign user terminal 34.

[0110] During the step 102 of transmitting presence beacons, the removable communication module 30 is in a state ready to pair for a first pairing; also called exclusive pairing since it makes it possible to define the exclusive user terminal with which it will have the capacity to pair.

[0111] It is noted that the sending of the presence beacons is interrupted with or following the recording step 114. The sending of the presence beacons can resume from the disconnection step 128; for example by modifying the presence beacons.

[0112] After the disconnection step 128, the exclusive removable communication module 30 again transmits presence beacons. This new sending can start as soon as the removable communication module 30 is powered, or after a predefined duration after the disconnection step 128. In the presence beacon transmission step 102, said presence beacons can be first presence beacons; for example with an availability message for defining an exclusive pairing. After the disconnection step 128, the presence beacons are optionally second presence beacons, without an availability message for defining an exclusive pairing.

[0113] According to an option of the invention, at the registration step 114 the removable communication module 30 sends a pairing confirmation, signifying to the user terminal 32 that they are paired. Thus, the user terminal 32 becomes the exclusive user terminal. They form a closed communication network.

[0114] After disconnection, the exclusive user terminal 32 and the removable communication module 30 are able to pair again; and therefore to communicate again, for example after the erasure step 138 and / or after the disconnection step 128. In this context, one or the other sends presence messages or pairing requests. When the exclusive user terminal 32 communicates its terminal identifier, the pairing is effective. The same coding characteristics described above are applied.

[0115] Only the exclusive user terminal automatically connects to the removable communication module 30 and automatically retrieves the diagnostic data therefrom by means of a diagnostic data request. This request includes the identification data of the exclusive user terminal which allows the removable communication module to recognize it. In this way, the invention optimizes the security and speed of retrieval of the diagnostic data.

[0116] In the case where the possible foreign user terminal 34 issues a connection request, this request is ignored since it occurs after the registration prohibition step 116. This foreign user terminal 34 may have started the same data transmission application as the exclusive user terminal. During such a request, the foreign user terminal 34 communicates its subsequent terminal identifier. Since the removable communication module 30 receives this foreign user terminal identifier, it compares it to the identification data of the exclusive user terminal. To the extent that these identifiers differ, the removable communication module 30 prohibits pairing. Indeed, even if the user terminal foreigner uses the same time function as the user terminal, their own identifiers differ. In addition, the foreign pairing request date will also differ.

[0117] Then, the removable communication module 30 deletes the foreign terminal identifier from its internal memory after the comparison which has proven negative. Therefore, even if the foreign user terminal 34 uses the application compatible with the removable communication module 30, the latter does not establish the pairing, nor the transmission of the data. Thus, security is preserved. In parallel, it deletes the corresponding data to preserve its memory.

Claims

Claims

1. Method for transmitting diagnostic data of a motor vehicle (10) between a user terminal (32) and a removable communication module (30) connected to a diagnostic port of the motor vehicle (10); characterized in that the transmission method comprises the following steps: • transmission (102) of presence beacons by the removable communication module (30); • reception (104) of one of the presence beacons by the user terminal (32); • sending (110) of a pairing request by the user terminal (32); said pairing request comprising identification data of said user terminal (32); • reception (112) of the pairing request by the removable communication module (30); • recording (114) at least partially of the identification data in the removable communication module (30);then • prohibition (116) of recording identification data of a foreign user terminal in the removable communication module (30), so that said user terminal (32) then constitutes an exclusive user terminal associated with the removable communication module (30); • transmission (120) of diagnostic data by the removable communication module (30) to the exclusive user terminal (32).;

2. Method according to claim 1, characterized in that following the recording step (114), the method comprises a step of stopping (118) the emission of presence beacons; preferably in the recording step (114), said identification data are recorded in a non-volatile memory of the removable communication module (30).

3. Method according to one of claims 1 to 2, characterized in that the removable communication module (30) comprises a recorded unlocking key; in the step of sending (110) a request pairing by the user terminal (32); said pairing request comprises an issued unlocking key; and the method further comprises a step of comparing (113) the issued unlocking key with the recorded unlocking key; then provided that the issued unlocking key corresponds to the recorded unlocking key, the method performs the recording step (114).

4. Method according to one of claims 1 to 3, characterized in that following the reception step (104); the method further comprises a step of defining (108) a time-variable key in the user terminal identification data (32), preferably at the transmission step (120), the diagnostic data being encrypted according to said time-variable key.

5. Method according to claim 4, characterized in that at the defining step (108) the time-variable key is calculated as a function of a time data; and at the recording step (114), the time-variable key is recorded in the removable communication module.

6. Method according to one of claims 4 to 5, characterized in that the identification data comprises a terminal identifier of the user terminal (32); in the definition step (108) the time variable key is calculated as a function of the module identifier and the terminal identifier of the user terminal (32).

7. Method according to one of claims 1 to 6, characterized in that from the step of transmitting (120) data, the method comprises a step of iterative measurement (124) of signal power by the removable communication module (30); then a step of comparing (126) the signal power with respect to a disconnection criterion; then a step of disconnecting (128) the removable communication module (30) from the exclusive user terminal (32) when the signal power reaches the disconnection criterion.

8. Method according to claim 7, characterized in that in the step of receiving (112) the pairing request, the method comprises an initial measurement step (106) of a reference power of the pairing request by the removable communication module (30); the disconnection criterion is a function of the reference power.

9. Method according to claim 8, characterized in that the disconnection criterion is at most 30% of the reference power, preferably at most 50% of the reference power.

10. Method according to one of claims 1 to 9, characterized in that the method further comprises: a step of receiving (130) a subsequent terminal identifier of a subsequent user terminal; a step of comparing (132) the subsequent terminal identifier with an exclusive terminal identifier of the exclusive user terminal; the method repeating the step of transmitting (120) diagnostic data by the removable communication module (30) provided that the subsequent terminal identifier corresponds to the exclusive terminal identifier.

11. Method according to claim 10, characterized in that when the subsequent terminal identifier differs from the exclusive terminal identifier, the method comprises a step of erasing (138) identification data by the removable communication module (30).

12. Method according to one of claims 1 to 11, characterized in that in the step of sending (110) a pairing request, the signal power of the pairing request is constant for a duration threshold, and / or the signal power of the pairing request is greater than or equal to a second power threshold.

13. Method according to one of claims 1 to 12, characterized in that before the step of transmitting (102) the presence beacons, the method comprises the following steps: • starting a data transmission application on the user terminal (32); • searching for a removable communication module (30) by the user terminal (32); • identifying a removable communication module (30) by the user terminal (32).

14. Computer program comprising instructions which, when the program is executed by a computer, cause the latter to implement a method for transmitting diagnostic data of a motor vehicle (10) between a user terminal (32) and a removable communication module (30) connected to a diagnostic port of the motor vehicle (10); the removable communication module (30) having a module identifier; characterized in that the transmission method comprises the following steps: • transmission (102) of presence beacons by the removable communication module (30); • reception (112) of a pairing request by the module removable communication (30); said pairing request comprising identification data of said user terminal (32); • recording (114) at least partially the identification data of the user terminal (32) in the removable communication module (30); and • prohibition (116) of recording identification data of a foreign user terminal in the removable communication module (30), so that said user terminal (32) then constitutes an exclusive user terminal associated with the removable communication module (30); • transmission (120) of diagnostic data by the removable communication module to the exclusive user terminal (32).

15. Removable communication module (30) of a system for transmitting operating data from a motor vehicle (10) to a user terminal (32) comprising identification data, said removable communication module (30) being intended to be connected to an on-board diagnostic port of a motor vehicle (10); characterized in that said removable communication module (30) is configured to: • emit presence beacons; • receive a pairing request from a user terminal (32); said pairing request comprising identification data of said user terminal (32); • prohibit recording of identification data of a foreign user terminal in the removable communication module (30), so that said user terminal (32) then constitutes an exclusive user terminal associated with the removable communication module (30); • record at least partially the identification data; and • transmit diagnostic data to the exclusive user terminal (32).

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