METHOD FOR DIAGNOSING AN ELECTRIFIED VEHICLE AUXILIARY BATTERY AND DIAGNOSTIC SYSTEM

Abstract

The present invention relates to a method for identifying the cause of failure in a diagnostic test of a service battery (12) in a DC voltage network of a first electrified vehicle (100) implemented by a diagnostic system (1) comprising the transmission of electrical parameters (D1, D2, D3) to a first diagnostic analysis device (200), the monitoring of a number of successive diagnostic test failures, the identification of the cause of the successive failures from said transmitted electrical parameters (D1, D2, D3), the generation of an alert including information on the cause of the failures detected by the first diagnostic analysis device (200), and the transmission of said alert to a second device (300) for monitoring fault handling of the service battery for a set comprising the first and second electrified vehicles. Figure 1.

Description

Title of the invention: METHOD FOR DIAGNOSING AN ELECTRIFIED VEHICLE AUXILIARY BATTERY AND DIAGNOSTIC SYSTEM

[0001] The field of the invention relates to a method for identifying a cause of a diagnostic failure of a service battery of an electrified vehicle.

[0002] Electrified vehicles, both hybrid and fully electric, can start even when the auxiliary battery (12 volts) is in a degraded state. A degraded state is defined as a state where the battery struggles to maintain a sufficient voltage level in the vehicle's electrical system under significant electrical loads. Generally, for internal combustion engine vehicles, this battery degradation can be detected as soon as the internal combustion engine starts.

[0003] Furthermore, electric vehicles include safety-critical electrical equipment that must be powered at all times while driving. This safety-critical or priority equipment includes, for example, an electric braking system, an electric power steering system, or a vehicle stability control system. In particular, during emergency braking or evasive maneuvers, the auxiliary battery plays a crucial role, as it must guarantee minimum voltage levels to this equipment in the event of a failure of the electrical power source, generally the DC-DC converter. Therefore, for safety reasons, it is necessary to test the auxiliary battery when starting the vehicle to verify with certainty its ability to meet safety requirements.

[0004] Prior art is known French patent application FR-A1-3122260 describing a method for diagnosing the operating status of an electrical energy storage device in a motor vehicle, designed to prevent incorrect diagnoses made by a remote tester. Prior art is also known French patent application WO-A1-2023 / 021247 describing a device for supervising tests of a vehicle's auxiliary battery configured to stress the battery by means of one or more successive current draws in order to evaluate electrical parameters, such as its internal resistance and minimum voltage. The supervising device is judiciously configured to prevent situations where the test result is false by ensuring the operability of a device isolating it from the electrical network.Furthermore, provisions are made for estimating the reliability of a test based on the reliability level of the measured values ​​of the electrical parameters.

[0005] Despite these test reliability checks, when an alert is triggered, it has been observed that repair services do not always correctly identify the cause of the electrical failure. This results in the replacement of the auxiliary battery or the DC-DC voltage converter when these components are not actually the source of the electrical failure.

[0006] There is therefore a need to address the aforementioned problems. One objective of the invention is to strengthen and improve the detection of electrical faults in electrified vehicles. Another objective is to improve the operation and control of safety-critical electrical systems. A further objective is to improve diagnostics and the operation of after-sales services for electrified vehicles.

[0007] More specifically, the invention relates to a method for identifying a cause of failure of a diagnostic test of a service battery of a DC voltage network of a first electrified vehicle implemented by a diagnostic system comprising the following steps:

[0008] - the execution of the auxiliary battery diagnostic test performed by a sub monitoring of the first vehicle, including the determination of a state parameter representative of a diagnostic test failure based on the electrical behavior of the auxiliary battery during the test,

[0009] - the collection of electrical parameters during each diagnosis,

[0010] the process further comprising the following steps:

[0011] - the transmission of said electrical parameters to a first analysis device diagnostic

[0012] - monitoring a number of successive failures of the diagnostic test performed by the first vehicle implemented by the first diagnostic analysis equipment,

[0013] - the identification of a cause of successive failures by the first equipment diagnostic analysis based on the aforementioned transmitted electrical parameters,

[0014] - the generation of an alert including information on the cause of the failures detected by the first diagnostic analysis equipment and the transmission of said alert to a second auxiliary battery fault handling supervision equipment for a set including the first and second electrified vehicles.

[0015] The method according to the invention may include the following additional features, alone or in combination:

[0016] - Preferably, the identification step is executed when the number of failures of successive diagnoses exceed a failure threshold, for example six successive failures.

[0017] - The auxiliary battery diagnostic test includes a first sub-step diagnostic consisting of activating consumer equipment powered by said a DC voltage network by the supervisor of the first vehicle so as to generate a current demand, a second diagnostic sub-step consisting of driving the test during which the voltage converter supplying said DC voltage network is driven according to an adapted voltage profile allowing the generation of a current demand to the auxiliary battery to power the consuming equipment, and a third diagnostic sub-step consisting of determining the state of the diagnostic test failure parameter based on the electrical behavior of the auxiliary battery during the current demand, and in which said parameters transmitted during the transmission step include at least some of the first diagnostic test parameters including at least some information delivered by the supervisor,the second parameters of the electrical response of the auxiliary battery and a parameter representing the number of successive failures of the diagnostic test.

[0018] - The step of transmitting said electrical parameters to the first equipment diagnostic analysis is implemented by means of wireless radio frequency communication through a wide area communication network to a remote server hosting said first equipment.

[0019] - Identifying the cause of failures involves a first sub-step of detection consisting of monitoring a parameter representative of the voltage conversion state of the voltage converter during the execution of the diagnostic and reporting a converter failure based on the result of the first detection sub-step.

[0020] - - Identifying the cause of failures involves a second sub-step of detection consisting of monitoring a parameter representative of the state of the activation request of the consumer equipment during the execution of the diagnostic and reporting a failure of the supervisor of the first vehicle based on the result of the second sub-step of detection.

[0021] - Identifying the cause of the failures involves a third sub-step of detection consisting of monitoring a parameter representative of the activation state of the consumer equipment during the execution of the diagnostic and reporting a failure of the consumer equipment based on the result of the third detection sub-step.

[0022] - Identifying the cause of the failures involves a fourth sub-step of detection consisting of monitoring a parameter representative of the status of the voltage converter activation request driven by the supervisor of the first vehicle during the execution of the diagnostic and reporting a failure of the supervisor based on the result of the fourth detection sub-step.

[0023] - Identifying the cause of the failures involves a fifth sub-step of detection consisting of monitoring a parameter representative of the state of the request control of the voltage converter generated by a converter computer to generate the voltage profile setpoint during diagnostic execution and to signal a converter computer failure based on the result of the fifth detection substep and in which the identification of the cause of failures includes a sixth detection substep consisting of monitoring the voltage profile setpoint during diagnostic execution and the resulting converter voltage from the setpoint and signaling a converter failure based on the result of the sixth detection substep.

[0024] - Identifying the cause of the failures involves a seventh sub-step of detection consisting of monitoring a parameter representative of the current profile of the auxiliary battery and updating the parameters of the auxiliary battery during the execution of the diagnostic and reporting a failure of the auxiliary battery control unit based on the result of the seventh detection sub-step.

[0025] The invention further provides for a diagnostic system comprising a first electrified vehicle, a first remote diagnostic analysis equipment and a second auxiliary battery fault handling supervision equipment for an assembly comprising the first and second electrified vehicles, wherein the diagnostic system is configured for the implementation of the method according to any one of the preceding embodiments.

[0026] The diagnostic method and system according to the invention improves the identification of the causes of diagnostic failures in the auxiliary battery of a group of vehicles. The invention also improves the analysis of diagnostic data and the troubleshooting of faults.

[0027] Other features and advantages of the present invention will become more apparent upon reading the following detailed description, which includes embodiments of the invention given by way of non-limiting examples and illustrated by the accompanying drawings, in which:

[0028] [Fig-1] schematically represents a diagnostic system configured for the installation implementation of the diagnostic process according to the invention;

[0029] [Fig.2] is a functional diagram of the diagnostic process according to the invention.

[0030] Figure 1 represents an embodiment of a diagnostic system 1 configured for implementing the method according to the invention aimed at improving the identification of the causes of failure in diagnosing a service battery of an electrified vehicle and the troubleshooting of faults related to this diagnosis. In this embodiment, the system 1 comprises a first vehicle 100, a first diagnostic device 200, and a second device 300 for monitoring and troubleshooting faults in the service battery of vehicle 100 and a set of second vehicles.

[0031] More specifically, the vehicle 100 includes a supervisory computer 11, designated also by the term supervisor or electronic control unit, a service battery 12 coupled or controlled by a control computer 13 specific to the battery 12, a first analysis unit 14 of data D2 of the battery 12 delivered by the control computer 13, a second unit 15 of determining failure or success of diagnostic tests of the battery 12, a third unit 16 of counting the number of successive failures of the diagnostic test of the battery 12, a fourth unit 17 of transmitting a set of collected data including first DI data delivered by the supervisor 11 of the vehicle 100, second D2 data delivered by the computer 13 relating to the electrical parameters of the service battery 12 and the electrical response of the service battery during a diagnostic and third D3 data relating to the monitoring of failures and successes of the diagnostic tests.It should be noted that the term unit can be interpreted as a specific computer or a specific software function, and where one computer (e.g., supervisory computer 11) or several computers can implement one or more of said units.

[0032] More specifically, the auxiliary battery 12 is an energy storage unit intended to power a DC voltage network of the first vehicle 100. The auxiliary battery is a 12-volt type. The first vehicle 100 also includes a DC / DC voltage network (not shown in [Fig. 1]) operating at 12 volts intended to power the electrical systems of the first vehicle 100, in particular the computers of the on-board electrical systems. Among these on-board electrical systems are non-priority systems (e.g., heating systems) and priority or safety systems whose voltage levels must be secured and guaranteed at all times during operation, particularly during the activation of safety braking and avoidance maneuvers. Priority systems include, in particular, an electric braking system and a trajectory control system.Furthermore, the first vehicle 100 includes a DC-DC converter (not shown in [Fig. 1]) responsible for converting a voltage supplied by a main energy storage system (not shown in [Fig. 1]) of the first vehicle 100, at a voltage level higher than that of the auxiliary battery 12. The main energy storage system is designed to power an electric drive unit of the first vehicle 100, at a voltage ranging from 48 volts to several hundred volts, for example, of the 350 / 450 volt or 800 / 900 volt type. The main energy storage system includes, for example, lithium-ion electrochemical cells.

[0033] Furthermore, priority electrical systems must remain powered even in the event of a failure of the DC-DC voltage converter supplying the DC voltage network. To this end, the auxiliary battery 12 must be regularly checked to guarantee this function and support minimum voltage levels for each priority system in the event of a safety maneuver.

[0034] Consequently, the vehicle's monitoring computer 11 implements a diagnostic function for the auxiliary battery 12, which operates periodically, for example, at least each time the vehicle is started. This diagnostic function consists of performing an electrical stress test on the DC voltage network in order to simulate the peak current demands that may be placed on the auxiliary battery in the event of a failure of the voltage converter or the main energy storage system during so-called safety maneuvers.

[0035] More specifically, in this preferred, but not limiting, embodiment, the principle of the diagnostic test consists of activating an electrical power consumer supplied by the vehicle's electrical system, for example, a heating system comprising heating elements, and driving a voltage profile at the voltage converter specifically designed so that the voltage converter's contribution is zero at a given instant in order to test the battery's ability to respond, on its own, to a current demand. The diagnostic sequence will be described in more detail later in the description of the diagnostic method.

[0036] System 1 further comprises the first diagnostic analysis unit 200, whose main function, implemented by a functional unit 21, is to identify the causes of diagnostic failures and to generate an alert, implemented by a functional unit 22, containing information to inform the second fault-handling unit 300 of a set of second vehicles. In this preferred example, the first unit 200 is a remote server system hosting the fault-cause identification function 21. The first unit 200 comprises a microprocessor system and memory enabling the execution of the identification and alert generation function and is adapted for implementing a program for identifying the causes of diagnostic failures.The first device 200 is connected via wireless radio frequency communication to the first vehicle 100 and to all subsequent vehicles through a wide area communication network between one or more remote servers hosting said first device. The wireless communication network is, for example, a 4G or 5G cellular network. The first device 200 is therefore suitable for collecting information from several cooperative vehicles. This information includes electrical parameters, at least some initial parameters provided by the vehicle supervisor, parameters provided by the auxiliary battery control unit, and parameters related to the number of successive diagnostic failures for each vehicle.

[0037] The data collection and transmission unit 17 of the vehicle 100 includes communication means adapted for transmitting data with the equipment 200. The vehicle includes a telematics unit designed for this purpose, equipped with individual connection and identification means for use with a wireless communication network. Typically, the telematics unit can be equipped, for example, with a physical or software identification card (such as a SIM for "Subscriber Identification Module" or an eSIM for "Embedded Subscriber Identification Module") for its connection to a wide area data network.

[0038] The implementation of the fault identification function is based on the electrical parameters D1, D2, and D3, initially determined in raw format, i.e., as electrical signals, analog data, or digital data, and then communicated by the supervisor 11, the computer 13, and the vehicle unit 16 of the vehicle 100 to the data collection and transmission unit 17. These parameters D1, D2, and D3 are processed by the unit 17 and transmitted as data suitable for transmission to the first diagnostic analysis equipment 200 via wireless radio frequency communication, for example, using 4G or 5G communication.

[0039] The Dl parameters include information representative of the diagnostic test, including information on the control of the voltage profile, the voltage converter, and the voltage network. More specifically, these Dl parameters include information from a control request RQ_SQ_test of the DCDC voltage converter for the purposes of the service battery test, a control command CMD_CTP of the consumer equipment used for the test to increase the current drawn by the DCDC voltage network, for example, heating resistors, the voltage setpoint CS_DCDC sent to the DCDC voltage converter, the voltage measurement U_DCDC across the terminals of the DCDC voltage converter on the 12-volt DC voltage network side, the current measurement I_DCDC produced by the DCDC voltage converter to supply the DC voltage network (12 volts), and the general state ST_DCDC of the DCDC voltage converter.

[0040] The D2 parameters of the auxiliary battery's electrical response include, in particular, the auxiliary battery current I_bat 12, which by convention is measured as negative during discharge of the auxiliary battery into the DC network. The D2 parameters that allow for the determination of a diagnostic failure include representative information of the minimum voltage value Ubat_min across the auxiliary battery terminals (expressed in volts), the internal resistance value Rint_bat (expressed in ohms), and representative information of the status of this data ST_Rint, allowing for an assessment of the reliability level of the preceding information provided during the diagnostic test so as to to determine if they can be used to characterize the state of the auxiliary battery.

[0041] The D3 parameters include at least one piece of information representing a failure and the number of successive failures CPT_Dg_Failure of the diagnostic test.

[0042] Units 14, 15, and 16 are used to perform diagnostics and count the number of successive diagnostic test failures. More specifically, unit 14 analyzes the D2 parameters received from the control unit 13 of the auxiliary battery 12. These parameters are transmitted via an onboard wired communication bus, for example, a CAN (Controller Area Network) type bus. Unit 14 provides unit 15 with D2 data including information representing the internal resistance Rint_bat and the minimum voltage Ubat_min of the auxiliary battery during a diagnostic test.

[0043] More specifically, unit 14, at each current draw during the diagnostic test, must update the internal resistance Rint_bat and minimum voltage Ubat_min information. Furthermore, unit 14 receives the ST_Rint reliability information associated with this data from the computer 13 in order to estimate a reliability level for this data.

[0044] Unit 15 is configured to determine whether the diagnostic test was executed, or whether its execution failed to update the internal resistance information Rint_bat, the minimum voltage Ubat_min, and the associated reliability information ST_Rint. If the diagnostic test was not executed or if the D2 information was not updated following a test, then this unit detects that the diagnostic test failed. Unit 15 outputs a Dg_Fail signal indicating the detection of a failure.

[0045] Furthermore, unit 16 is configured to count the number of successive failures of a diagnostic test on the auxiliary battery, based on the Dg_Failure signal, over a period encompassing several driving cycles, i.e., several vehicle start and stop cycles. This function implements a counter that increments a variable with each detected failure. This function thus makes it possible to detect and identify a persistent fault in the auxiliary battery. Unit 16 delivers a CPT_Dg_Failure signal to unit 17, thereby informing equipment 200 to identify the causes of the failures using all the DI and D2 data that were also collected during the execution of a diagnostic test. Unit 17 is configured to transmit information D3 representing the total number of failures during vehicle use and / or the number of successive diagnostic test failures.

[0046] Furthermore, the first diagnostic analysis equipment 200 includes an identification unit 21 for determining the cause of diagnostic failures from the data received D1, D2, and D3 from the first vehicle and the second vehicles. The identification unit implements an identification function for each collaborative vehicle and delivers information representative of the cause of diagnostic failures in a service battery. A unit 22 is responsible for generating an alert identifying the possible cause and transmitting it to the second equipment 300 for monitoring fault handling of the service battery of a set of electrified second vehicles.

[0047] The second piece of equipment may be a server or a server system providing a fault monitoring service for a repair shop network or a vehicle after-sales service network. The second piece of equipment is connected via data communication to the first piece of equipment, typically through an internet-type computer network or a proprietary network, which may be wireless or wired radio frequency. This second piece of equipment 300 enables after-sales services to be informed of the causes of failure affecting the first vehicle specifically or the causes affecting a group of second vehicles, in order to improve fault handling.

[0048] In [Fig. 2], the method for identifying a cause of diagnostic failure according to the invention is represented in the form of a functional block diagram. This method is implemented by a diagnostic system as described in [Fig. 1].

[0049] In a first step E1, the method involves performing a diagnostic check of the auxiliary battery by an electric motor vehicle. This diagnostic check is triggered periodically, for example, at each start-up or each driving cycle of a vehicle. In this preferred example, the vehicle's monitoring computer detects the start-up and verifies that the vehicle's DC-DC voltage converter, which connects a high-voltage network supplied by the main storage system to a low-voltage network to which the auxiliary battery is connected, is active and capable of performing the voltage conversion.

[0050] Next, according to the diagnostic procedure, a first substep, controlled by the supervisory computer, consists of activating a consumer device powered by the DC (12-volt) network by the vehicle supervisor so as to generate a current demand, for example, a request generating an additional current requirement of approximately 40 amps, for example, compared to the consumption prior to the activation of the consumer device. This consumer device is, for example, an electric resistance heating system.

[0051] During the first step E1, the method further comprises a second diagnostic substep consisting of conducting a test during which the voltage converter is driven according to a suitable voltage profile, generating a current demand on the auxiliary battery to power the consuming equipment. In response to this profile, the DC-DC converter's control unit converts it into a voltage setpoint that varies between a first high value (for example, 13.1 volts) allowing a 12-volt DC power supply to the network. The current is supplied solely by the converter (the contribution from the service battery is then zero), and a second, lower value (for example, 10.6 volts) aims to reduce the DC-DC converter's contribution to the 12-volt DC power supply to 0 amps (the 12-volt service battery's contribution to the DC power supply is then total). Thus, during the execution of the voltage profile, the current supplied by the service battery varies dynamically between 0 amps and the total current demanded by the power supply.

[0052] During the first step El, the method further comprises a third diagnostic substep consisting of determining the values ​​of the electrical parameters of the internal resistance Rint_bat and the measured minimum voltage Ubat_min reached at the time of each current demand. This third substep is implemented by the analysis unit 14. During this third substep, the method further comprises determining the capacity of the auxiliary battery to meet each current demand and the state of the failure parameter Dg_echec of the diagnostic test as a function of the electrical behavior of the auxiliary battery during the current demand, in particular based on the state of the reliability signal and the updating of the minimum voltage and internal resistance values.

[0053] More specifically, the analysis unit determines three cases. In the first case, the reliability information determines that the internal resistance Rint_bat and minimum voltage Ubat_min data are unreliable, triggering a failure detection. In the second case, the reliability information determines that the data is reliable. The internal resistance Rint_bat and minimum voltage Ubat_min parameters are then updated. In the third case, the reliability information determines that the data is reliable; however, it is detected that the internal resistance Rint_bat and minimum voltage Ubat_min parameters remain fixed during the current draw of the auxiliary battery. This situation consequently triggers a diagnostic test failure detection.

[0054] Next, the method includes a step E2 of collecting the electrical parameters D1, D2, and D3 during each diagnostic test. The collection is carried out via the on-board communication bus for data processing, enabling its transmission to the first diagnostic analysis unit 200. The collection is implemented, for example, by a vehicle computer designed to centralize data and information.

[0055] Next, the method includes a step E3 of transmitting said electrical parameters D1, D2 and D3 to the first diagnostic analysis device 200. In this preferred embodiment, the first device 200 is hosted on a remote server in order to centralize the data from several vehicles in order to implement comprehensive monitoring and troubleshooting of faults across all of the car manufacturer's vehicles. E3 transmission is therefore implemented via wireless radio frequency communication through a wide area network, such as 4G or 5G, or via satellite communication, to the remote server hosting the first 200 equipment. In most cases, this E3 transmission occurs during normal vehicle use, for example at the driver's home, at startup, or while the vehicle is charging.

[0056] However, the possibility is not excluded that the diagnostic analysis function 21 and the function for generating an alert 22 including information on the cause of failures may be hosted on an on-board computer of a vehicle.

[0057] Next, according to the invention, the method includes a monitoring step E4 of the number of successive failures of the diagnostic test performed by the first vehicle. This step E4 is implemented by the first diagnostic analysis equipment 200. More specifically, monitoring E4 consists of comparing the number of successive failures to a predetermined failure threshold, for example, six consecutive failures. As soon as the threshold is exceeded, an alert is first generated in a control unit of the first vehicle, for example, via a warning light, so that the driver can have their vehicle checked. The 12-volt DC power supply system is an essential and safety-critical function; therefore, it is necessary to alert the fault monitoring and troubleshooting teams, and first and foremost, the owner of the vehicle concerned.

[0058] Furthermore, in the case of the invention, the method provides that if the number of failures is detected to be greater than this failure threshold, the method includes a step E5 of identifying a cause of the successive failures by the first diagnostic analysis equipment 200 based on said transmitted electrical parameters D1, D2 and D3. This makes it possible to ensure a comprehensive analysis of all vehicles in an automated manner in order to prevent a systematic risk on a large scale.

[0059] This identification step E5 includes several failure cases detectable specifically by the detection substeps described in more detail below, allowing for a more thorough diagnosis and identification of the vehicle system likely to have caused the repeated failures. At least seven failure cases are included.

[0060] During E5 identification, a first detection substep consists of monitoring the ST_DCDC parameter, among the Dl parameters, which represents the voltage conversion state of the voltage converter during diagnostic execution. If it is detected that the voltage converter is not in voltage conversion operation, then the first substep signals a converter failure by means of a signal or data containing information identifying the converter. tension as the cause of the failure specifically, for example via a specific alert code.

[0061] During E5 identification, a second detection substep consists of monitoring a parameter of the CMD_CTP request, among the D1 parameters, representative of the activation request status of the consumer equipment during diagnostic execution. If it is detected that the CMD_CTP request was not issued by the supervisory control unit of the first vehicle, then the second substep involves reporting a failure of the vehicle supervisory control unit by means of a signal or data containing information identifying the supervisory control unit as the cause of the failure specifically, for example via a specific warning code.

[0062] During E5 identification, a third detection substep consists of monitoring a parameter, from among the data D1 or D2, representative of the activation state of the consumer equipment during diagnostic execution, for example, an activation state parameter of the consumer equipment, the value of the network currents I_DCDC or the service battery current I_bat. If it is detected that the consumer equipment is not activated, the third substep includes reporting a failure of the consumer equipment by means of a signal or data including information identifying the consumer equipment as the cause of the failure specifically, for example via a specific alert code.

[0063] During E5 identification, a fourth detection substep consists of monitoring a parameter, among the Dl data, representative of the status of the RQ_SQ_test voltage converter activation request driven by the supervisor of the first vehicle during diagnostic execution. If it is detected that the supervisor control unit is not issuing the request, the fourth substep includes reporting a supervisor failure by means of a signal or data containing information identifying the supervisor control unit as the cause of the failure specifically, for example via a specific warning code.

[0064] During E5 identification, a fifth detection substep consists of monitoring the RQ_SQ_test parameter, which represents the status of the voltage converter control request generated by a converter computer to generate the CS_DCDC voltage profile setpoint during diagnostic execution, and whether this computer generates the resulting voltage profile setpoint. If it is detected that the request is issued but the CS_DCDC setpoint is not driven, then this fifth substep signals a failure of the converter computer by means of a signal or data containing information identifying the converter computer as the specific cause of the failure, for example, via a specific warning code.

[0065] During E5 identification, a sixth detection substep involves monitoring the setpoint of the voltage profile CS_DCDC during diagnostic execution and the resulting converter voltage U_DCDC. If it is detected that the converter is not driving the voltage U_DCDC, then the sixth substep includes reporting a converter failure by means of a signal or data containing information that specifically identifies the converter as the cause of the failure, for example, via a specific alert code.

[0066] Finally, during E5 identification, a seventh detection substep consists of monitoring the representative parameter of the auxiliary battery current profile, I_bat, and updating the auxiliary battery parameters during diagnostic execution. If it is detected that the characteristic electrical parameters of the battery are not being updated, the seventh substep includes reporting a failure of the auxiliary battery control unit by means of a signal or data containing information identifying the auxiliary battery control unit as the specific cause of the failure, for example, via a specific warning code.

[0067] Finally, the invention includes a step E6 for generating an alert from the signals and data generated during the identification step E6, including information on the cause of the failures. The alert is transmitted from the first device 200 to the second device 300, which monitors fault handling of the auxiliary battery for a set of electrified secondary vehicles. This information sharing allows for centralized diagnostics by a service whose purpose is to improve the management of electrical system developments and repairs. In particular, this avoids the need to replace the battery if another piece of equipment fails during the diagnostic process. This alert explicitly indicates the cause of the failure, for example, via a code or the relevant information.

[0068] In one embodiment of the method, it is envisaged that the step of identifying the cause of a failure can be performed before the failure threshold is reached. The causes of failures can be recorded in the memory of the first piece of equipment 200 in order to maintain a history of the causes of failures.

[0069] The invention provides for one or more computers equipped with memories for storing programs containing instructions which, when executed, lead them to implement the method for identifying the causes of failure of a diagnostic test of an auxiliary battery according to the invention. The computers and programs are distributed within the diagnostic system among the vehicle systems, platforms, and remote servers according to the desired hardware architecture. The computers and memories are equipped with integrated circuits and can be of FPGA type (“Field Programmable Gate Array”, DSP (“Digital Signal Processor”), ASIC (“Application Specified Integrated Circuit”) for example.

[0070] The invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different variant embodiments of the invention by combining, for example, the different features above taken alone or in combination, without departing from the scope of the invention.

Claims

Claims

1. Method for identifying a cause of failure of a diagnostic test of a service battery (12) of a direct voltage network of a first electrified vehicle (100) implemented by a diagnostic system (1) comprising the following steps: - the execution (El) of the diagnostic test of the service battery (12) carried out by a supervisor (11) of the first vehicle (100) comprising the determination of a state parameter representative of a failure (Dg_Failure) of the diagnostic test as a function of the electrical behavior of the service battery (12) during the test, - the collection (E2) of electrical parameters (Dl, D2, D3) during each diagnosis, the method being characterized in that it comprises the following steps: - the transmission (E3) of said electrical parameters (D1, D2, D3) to a first diagnostic analysis equipment (200), - monitoring (E4) a number of successive failures of the diagnostic test performed by the first vehicle (100) implemented by the first diagnostic analysis equipment (200), - the identification (E5) of a cause of the successive failures by the first diagnostic analysis equipment (200) from said transmitted electrical parameters (D1, D2, D3), - the generation (E6) of an alert comprising information on the cause of the failures detected by the first diagnostic analysis equipment (200) and the transmission (E6) of said alert to a second equipment (300) for supervising the processing of faults in the service battery for an assembly comprising the first and second electrified vehicles.

2. The method of claim 1 wherein the diagnostic test of the service battery (12) comprises: - a first diagnostic sub-step consisting of activating consumer equipment supplied by said direct voltage network by the supervisor (11) of the first vehicle (100) so as to generate a current demand, - a second diagnostic sub-step consisting of controlling the test during which the voltage converter supplying said direct voltage network is controlled according to a suitable voltage profile allowing the generation of a current demand to the service battery (12) to power the consumer equipment, - and a third diagnostic sub-step consisting of determining the state of the failure parameter (Dg_echec) of the diagnostic test as a function of the electrical behavior of the service battery (12) during the current demand, and in which said parameters (Dl, D2, D3) transmitted during the transmission step (E3) comprise at least first parameters (Dl) of the diagnostic test including at least information delivered by the supervisor (11), second parameters (D2) of the electrical response of the service battery (12) and a parameter (D3) representative of the number of successive failures (CPT_Dg_Echec) of the diagnostic test.

3. Method according to claim 2, in which the step of transmitting (E3) said electrical parameters (D1, D2, D3) to the first diagnostic analysis equipment (200) is implemented by wireless radiofrequency communication means through a wide area communication network to a remote server hosting said first equipment.

4. A method according to claim 2 or 3, wherein the identification (E5) of the cause of the failures comprises a first detection sub-step consisting of monitoring a parameter representative of the voltage conversion state of the voltage converter during the execution of the diagnosis and signaling a failure of the converter depending on the result of the first detection sub-step.

5. Method according to any one of claims 2 to 4, in which the identification (E5) of the cause of the failures comprises a second detection sub-step consisting of monitoring a parameter representative of the state of the activation request of the consumer equipment during the execution of the diagnosis and signaling a failure of the supervisor (11) of the first vehicle (100) according to the result of the second detection sub-step.

6. Method according to any one of claims 2 to 5, in which the identification (E5) of the cause of the failures comprises a third detection sub-step consisting of monitoring a parameter representative of the activation state of the consumer equipment during the execution of the diagnosis and signaling a failure of the consumer equipment according to the result of the third detection sub-step.

7. Method according to any one of claims 2 to 6, in which the identification (E5) of the cause of the failures comprises a fourth detection sub-step consisting of monitoring a parameter representative of the state of the activation request of the voltage converter controlled by the supervisor (11) of the first vehicle (100) during the execution of the diagnosis and signaling a failure of the supervisor (11) according to the result of the fourth detection sub-step.

8. Method according to any one of claims 2 to 7, in which the identification (E5) of the cause of the failures comprises a fifth detection sub-step consisting of monitoring a parameter representative of the state of the voltage converter control request generated by a converter computer to generate the voltage profile setpoint during the execution of the diagnosis and to signal a failure of the converter computer according to the result of the fifth detection sub-step and in which the identification of the cause of the failures comprises a sixth detection sub-step consisting of monitoring the voltage profile setpoint during the execution of the diagnosis and the converter voltage resulting from the setpoint and to signal a converter failure according to the result of the sixth detection sub-step.

9. Method according to any one of claims 1 to 8, in which the identification (E5) of the cause of the failures comprises a seventh detection sub-step consisting of monitoring a parameter representative of the current profile of the service battery (12) and updating the parameters of the service battery during the execution of the diagnosis and signaling a failure of the calculator of the service battery according to the result of the seventh detection sub-step.

10. Diagnostic system (1) comprising a first electrified vehicle (100), a first remote diagnostic analysis equipment (200) and a second equipment for supervising the processing of faults (300) of the service battery for an assembly comprising the first (100) and second electrified vehicles, characterized in that the diagnostic system (1) is configured for implementing the method according to any one of claims 1 to 9.

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