Method for evaluating the reliability of a monitoring system for a battery cooling system of a motor vehicle.

Abstract

Method for evaluating the reliability of a monitoring system for a battery cooling system of a motor vehicle. Method for evaluating the reliability of a monitoring system for a battery cooling system from data collected from a set of vehicles, each vehicle comprising: - a battery equipped with a cooling system, - a monitoring system for the cooling system, and - a means of communication with a centralized server.The process includes: - detection, by a vehicle in the group, of an initial fault diagnosis, then - from a time of initial determination of an initial fault diagnosis, an iteration on determining an initial reliability indicator of the monitoring system calculated by each vehicle in the first group, and - a third step of collecting, by the centralized server, the current value of the first reliability indicator for each vehicle in the first group. Figure for the abstract: 1.

Description

Title of the invention: Method for evaluating the reliability of a monitoring system for a cooling system of a battery of a motor vehicle.

[0001] The invention relates to a method for evaluating the reliability of a monitoring system of a cooling system of a battery of a motor vehicle.

[0002] Regulations will soon require monitoring of the traction battery in motor vehicles. In the event of a failure of the battery cooling system, vehicle users must be warned, for example by activating a dashboard warning light.

[0003] A battery cooling system monitoring system must take into account multiple driving situations that may influence the evolution of the observed parameters to determine a failure of the battery cooling system. In addition, the monitoring system must take into account variability of the measurement sensors from one vehicle to another, and variability of operation of the components involved in battery management (water pump, battery, compressor, etc.).

[0004] The development and adjustment of such a monitoring system is complex because two types of situations must be avoided: - false positive detection, i.e. sending an alert to the vehicle user while the battery cooling system is operating normally, - false negative detection, i.e. the absence of an alert to the vehicle user when the battery cooling system is faulty.

[0005] However, the occurrence of false positives can generate very strong dissatisfaction among vehicle users.

[0006] The aim of the invention is to provide a method for evaluating the reliability of a monitoring system of a battery cooling system, which overcomes the above drawbacks and improves the methods for evaluating the reliability of a monitoring system known from the prior art. In particular, the invention makes it possible to provide a method which is simple and reliable and which minimizes the number of false detections of a failure of a battery cooling system.

[0007] To this end, the invention relates to a method for evaluating the reliability of a monitoring system of a cooling system of a battery of a motor vehicle from data collected from a first set of vehicles, each vehicle of the first set comprising - a battery equipped with a cooling system, - a battery cooling system monitoring system, and - a means of communication (40) with a centralized server (50). In addition, the method for evaluating the reliability of a monitoring system for a cooling system of a battery of a motor vehicle comprises: - a first step of detection, by at least one vehicle of the set, of a first fault diagnosis, then - from a time of first determination of a first fault diagnosis, an iteration on a second step of determination of a first indicator of reliability of the monitoring system calculated by each at least one vehicle of the first set, and - a third stage of collection, by the centralized server, of the current value of the first reliability indicator of each at least one vehicle of the first set.

[0008] In one embodiment, the first detection step comprises: - a sub-step of determining a current state of the cooling system by the monitoring system of the at least one vehicle as being normal or abnormal, - followed by an iteration on the first step as long as the current state of the cooling system is determined to be normal.

[0009] In one embodiment, the second step comprises a sub-step of updating, by the at least one vehicle, a first reliability indicator of the monitoring system, the first reliability indicator being a quotient between, - on the one hand, a total number of detections by the monitoring system of the at least one vehicle, of a current state of the cooling system as being abnormal, measured between the time of first determination and an iteration time, and - on the other hand, a number of determinations of a current state of the cooling system of the at least one vehicle as being active, measured between the time of first determination and the time of iteration.

[0010] In one embodiment, the first step further comprises a calculation of the following data: - a total number of missions of at least one vehicle, - a total number of missions of at least one vehicle including a start-up of the battery cooling system, - a total number of determinations of a current cooling system state as normal.

[0011] In one embodiment, the second step further comprises a calculation of the following data: - a total number of missions of at least one vehicle, - a total number of missions of at least one vehicle including a battery cooling system route, - a total number of determinations of a current cooling system state as normal, - optionally, a quotient between i. on the one hand, a total number of detections by the monitoring system of a current state of the cooling system as being normal, measured between the time of first determination and the time of iteration, and ii. on the other hand, a number of determinations of a current state of the cooling system as being active, measured between the instant of first determination and the instant of iteration.

[0012] In one embodiment, the collection step comprises a transmission by the centralized server of a request intended for at least one vehicle selected from among the vehicles of the first set, and a reception by the centralized server of a response from each selected vehicle, said response containing a current value of a first reliability indicator of the monitoring system of the selected vehicle.

[0013] In one embodiment, said response further contains: - a total number of missions of the selected vehicle, - a total number of missions of the selected vehicle including a start-up of the battery cooling system, - a total number of determinations of a current state of the cooling system as normal, and - a quotient between i. on the one hand, a total number of detections by the monitoring system of a current state of the cooling system as being normal, measured between the time of first determination and the time of iteration, and ii. on the other hand, a number of determinations of a current state of the cooling system as being active, measured between the instant of first determination and the instant of iteration.

[0014] In one embodiment, the method comprises, following the collection step, a step of evaluating the reliability of the supervision system of each at least one selected vehicle comprising: - a sub-step of verifying the relevance of the first reliability indicator transmitted by the at least one selected vehicle, then, - if the first reliability indicator is considered irrelevant, an assessment of the reliability of the supervision system as being indeterminate, - if the first reliability indicator is considered relevant, an assessment of the reliability of the supervision system as being sufficient when the first indicator is equal to 1 with an accuracy of 0.1%, or even 0.01%, or even 0.001%, - otherwise an assessment of the reliability of the supervision system as being insufficient.

[0015] In one embodiment, the sub-step of verifying the relevance of the first reliability indicator comprises: - a determination of the first reliability indicator of a selected vehicle as irrelevant if the total number of missions of the selected vehicle is zero, or if the total number of missions of the selected vehicle including a cooling system start-up is zero, or if the number of detections, by the monitoring system, of a current state of the cooling system as being abnormal is zero, - otherwise a determination of the first reliability indicator as being relevant.

[0016] The invention further relates to a motor vehicle which comprises the hardware and software means for implementing the steps of the evaluation method according to the invention.

[0017] The invention also relates to a device for evaluating the reliability of a monitoring system for a cooling system of a battery of a motor vehicle, the motor vehicle being equipped with a battery, a battery cooling system, a monitoring system for the battery cooling system, and a means of communication with a centralized server, the device comprising hardware and / or software elements implementing the method for evaluating the reliability of a monitoring system for a cooling system of a battery of a motor vehicle, in particular hardware and / or software elements designed to implement the method according to the invention, and / or the device comprising means for implementing the method according to the invention.

[0018] The invention also relates to a computer program product comprising program code instructions recorded on a computer-readable medium for implementing the steps of the method according to the invention when said program operates on a computer or computer program product downloadable from a communication network and / or recorded on a data medium readable by a computer and / or executable by a computer, the method comprising instructions which, when the program is executed by the computer, lead the latter to implement the method according to the invention.

[0019] The invention also relates to a computer-readable data recording medium on which is recorded a computer program comprising program code instructions for implementing the method according to the invention or a computer-readable recording medium comprising instructions which, when executed by a computer, cause the latter to implement the method according to the invention.

[0020] The invention also relates to a signal of a data medium, carrying the computer program product according to the invention.

[0021] The attached drawing represents, by way of example, an embodiment of an evaluation device according to the invention and an embodiment of an evaluation method according to the invention.

[0022] [Fig.l] illustrates a high-level architecture of an evaluation device according to the invention.

[0023] [Fig.2] is a flowchart of a mode of execution of an evaluation method according to the invention.

[0024] An example of an embodiment of a device 70 for evaluating the reliability of a monitoring system of a cooling system of a battery of a motor vehicle is described below with reference to FIGS. 1 and 2.

[0025] [Fig.l] illustrates an overall architecture of a device 70 for evaluating the reliability of a monitoring system of a battery cooling system according to the invention. The device 70 comprises a centralized evaluation system 50 communicating with a local supervision system 60 on board each of the vehicles 101, 102, 103 of a first set 100 of vehicles.

[0026] In the remainder of the document, - the centralized evaluation system 50 may be named “system 50” or “centralized system 50”, or “centralized server 50” and - the local supervision system 60 may be called “system 60” or “local system 60”.

[0027] The first set 100 of vehicles may also be referred to as “fleet 100” in the remainder of the document.

[0028] Each of the motor vehicles 101, 102, 103 may be a motor vehicle of any type, including a passenger vehicle, a utility vehicle, a truck, or a public transport vehicle such as a bus or a shuttle.

[0029] Each vehicle of the fleet 100 comprises a traction battery 10 equipped with a cooling system 20 and a monitoring system 30 of the cooling system 20.

[0030] The battery 10 comprises a set 11 of battery cells, and at least one temperature sensor 12 of a battery cell of the set 11.

[0031] Each vehicle of the fleet 100 is further equipped with a means of communication 40 with the centralized server 50.

[0032] Each vehicle of the fleet 100 further comprises a local evaluation device 60 of the reliability of the monitoring system 30 of the cooling system 20.

[0033] In the remainder of the document, the term “mission” designates a period of use of the vehicle between the start of a mission and the end of a mission, the start and the end of a mission which can be materialized by the use of a key or any other means of locking and unlocking the vehicle. Alternatively, the start and end of the mission could be materialized by a starting point and an arrival point of a route entered in a vehicle navigation system. Alternatively, by "mission", we can designate a phase of driving of the motor vehicle.

[0034] During certain missions, in particular during missions in urban areas, the cooling system 20 of the battery 10 is rarely activated. Alternatively, when a mission of the vehicle includes, for example, a journey in the mountains, then the cooling system 20 is likely to be activated to cool the battery 10. The activation of the cooling system 20 further depends on a driving style of the driver of the vehicle. The number N_Tot_M_refroid counts the total number of missions, since the vehicle was put into circulation, during which battery cooling was carried out.

[0035] When the cooling system 20 is activated, its operation is supervised by a monitoring system 30 fitted to the vehicle. In one embodiment, the monitoring system 30 may use different measurements to detect an abnormal state of the cooling system 20.

[0036] The fluid used for cooling the battery 10 may be glycolated water, refrigerant fluid or air. A sensor 21 is advantageously adapted to the cooling fluid used to detect an abnormal state of the cooling system. In a case where it is a refrigerant fluid system, to detect an abnormal state of the cooling system 20, the supervision system can monitor a pressure measurement of the cooling fluid which could be the reflection of the temperature of the fluid near the heat exchange zone with the battery.

[0037] Alternatively, the sensor 21 may be a temperature sensor monitoring the temperature of the cooling plate which allows heat exchange between the battery cells and the cooling fluid.

[0038] Advantageously, the verification processes implemented by the monitoring system 30 of each vehicle 101, 102, 103 are configurable, in particular as a function of adjustable tolerance thresholds. Thus, by calibrating tolerance thresholds of the monitoring system 30 of each vehicle 101, 102, 103, it is possible to reduce the number of false positives, i.e. the number of times where the monitoring system 30 wrongly detects a failure of the cooling system 20.

[0039] The local evaluation device 60 of the reliability of the monitoring system 30 of each vehicle 101, 102, 103 of the fleet 100 comprises a memory 61 making it possible to record data calculated by the evaluation device 60. The data recorded in the memory 61 can advantageously comprise: - a total number of missions N_Tot_M carried out by the motor vehicle since it was put into circulation, - a total number of missions N_Tot_M_refroid during which battery cooling was carried out, - a total number of determinations N_refroid_OK_total of a current state of the cooling system as being normal, - a quotient Q_NOK between, on the one hand, a number of detections N_refroid_NOK by the monitoring system of a current state of the cooling system as being abnormal, measured between the instant of first determination TO and the instant of iteration T_iter, and on the other hand, a number of determinations N_refroid_actif of a current state of the cooling system as being active, measured between the instant TO of first determination and the instant of iteration T_iter, and - optionally, a quotient Q_OK between on the one hand, a number of detections N_refroid_OK by the monitoring system, of a current state of the cooling system as being normal, measured between the instant of first determination TO and the instant of iteration T_iter, and on the other hand, a number of determination N_ refroid_actif of a current state of the cooling system as being active, measured between the instant TO of first determination and the instant of iteration T_iter.

[0040] In the remainder of the document, instant TO is a time of first determination of a current state of the cooling system 20 as being abnormal. In other words, if for a given vehicle of the fleet 100 no anomaly is detected, the time T0 relating to this given vehicle remains undetermined. Otherwise, the given vehicle determines an instant T0 corresponding to an instant of first detection, by the monitoring system 30, of an anomaly in the operation of the cooling system 20. The instant T0 is then an initial instant from which indicators relating to the operation of the cooling system 20 and the monitoring system 30 are counted.

[0041] In one embodiment, at each iteration time T_iter of the local evaluation system 60, the following indicators are updated as a function of the behavior of the cooling system 20 and the monitoring system 30: - the number of detections N_refroid_NOK by the monitoring system of a current state of the cooling system 20 as being abnormal between the instant T0 and the instant T_iter, - the number of determinations N_refroid_actif of a current state of the cooling system 20 as being active, measured between the instant T0 of first determination and the instant of iteration T_iter, - a quotient Q_NOK between the number of detections N_refroid_NOK and the number of determinations N_refroid_actif previously calculated,

[0042] In addition, at each iteration time T_iter of the local evaluation system 60, the following indicators are updated according to the behavior of the cooling system 20 and the monitoring system 30: - the number of N_refroid_OK detections by the monitoring system of a current state of the cooling system as being normal, measured between time T0 and time T_iter, and - a quotient Q_OK between the number of detections N_refroid_OK and the number of determinations N_refroid_actif previously calculated.

[0043] Advantageously, the quotients Q_NOK and Q_OK make it possible to measure the reliability of the operation of the monitoring system 30 of a given vehicle of the fleet 100.

[0044] Several situations are possible for each given vehicle in the fleet 100.

[0045] According to a first situation, the quotients Q_OK and Q_NOK may be undefined. This is the case when no start-up of the vehicle's cooling system has taken place since it was put into service.

[0046] According to a second situation, the instant T0 may be indefinite, which means that no anomaly has been detected by the monitoring system 30 since the vehicle was put into circulation and therefore that the number of false positives is zero. The number of false negatives is then indeterminate.

[0047] According to a third situation, the number N_refroid_NOK can be equal to the number N_refroid_actif, which means that from the instant T0, the cooling system 20 has always been detected as faulty by the monitoring system 30. The reliability indicator Q_NOK is then equal to 1. The third situation suggests a permanent failure of the cooling system 20 which would have been detected at the instant T0, and normal operation of the monitoring system 30.

[0048] According to a fourth situation, the number N_refroid_NOK can be strictly less than the number N_refroid_actif, which means that from the instant T0, the operation of the cooling system 20 has been detected as sometimes abnormal (or faulty) and sometimes normal by the monitoring system 30. The fourth situation evokes a failure of the monitoring system 30, the operation of the cooling system 20 being of an indeterminate nature.

[0049] The role of the centralized supervision system 50 is to collect and interpret data recorded by the local evaluation system 60 of each of the vehicles in the fleet 100.

[0050] In one embodiment, the centralized supervision system 50 is capable of evaluating the reliability of the local supervision system 30 installed in each of the vehicles of the fleet 100. For this, the centralized supervision system 50 is able to interrogate each vehicle in the fleet to collect operating indicators of the supervision system, in particular the quotient Q_NOK. In an alternative embodiment, the operating indicators of the supervision system can be transmitted automatically to the centralized supervision system 50. Such an automatic transmission can for example be carried out periodically; alternatively, an automatic transmission can be carried out upon modification of the quotient Q_NOK.

[0051] A mode of execution of a method for evaluating the reliability of a monitoring system of a cooling system of a battery of a motor vehicle is described below with reference to [Fig.2].

[0052] In a first detection step E10, at least one vehicle of the set 100 detects a first fault diagnosis.

[0053] The first step E10 comprises a sub-step of determining a current state CUR_S of the cooling system 20 by the monitoring system 30 of the at least one vehicle 101, 102, 103 as being normal or abnormal.

[0054] As long as the monitoring system 30 determines a current state CUR_S of the cooling system 20 as being normal, we loop back to step E10.

[0055] The first step E10 further comprises an update of the following data: - a total number of missions N_Tot_M of the at least one vehicle, - a total number of missions N_Tot_M_refroid of the at least one vehicle including a start-up of the battery cooling system, - a total number of determinations N_refroid_OK_total of a current state of the cooling system as normal.

[0056] If, at a time T0, the monitoring system 30 determines for the first time a current state CUR_S of the cooling system as being abnormal, then a second step E20 of monitoring the cooling system is continued from a first fault diagnosis, and step E20 is iterated.

[0057] The first iteration of step E20 is carried out upon detection of a first abnormal state of the cooling system 20 by the monitoring system 30. After the first iteration, other iterations of step E20 are carried out to update a set of data described below.

[0058] Step E20 notably comprises a sub-step E21 of updating a first reliability indicator Q_NOK of the monitoring system 30.

[0059] The reliability indicator Q_NOK is a quotient between, - on the one hand, a number of detections N_refroid_NOK, by the monitoring system 30 of a current state of the cooling system 20 as being abnormal, measured between the instant of first determination T0 and the instant of iteration T_iter, and, - on the other hand, a number of determinations N_refroid_actif of a current state of the cooling system as being active, measured between the instant T0 of first determination and the instant of iteration T_iter.

[0060] Step E20 further comprises a calculation of the following data: - a total number of missions N_Tot_M of at least one vehicle, - a total number of missions N_Tot_M_refroid of at least one vehicle including a start-up of the battery cooling system, - a total number of determinations N_refroid_OK_total of a current state of the cooling system as being normal, - a quotient Q_OK between on the one hand, a total number of detections N_refroid_OK by the monitoring system, of a current state of the cooling system as being normal, measured between the instant of first determination T0 and the instant of iteration T_iter, and on the other hand, a number of determinations of a current state of the cooling system as being active, measured between the instant T0 of first determination and the instant of iteration T_iter.

[0061] In parallel with the execution of steps E10 then E20 in each vehicle of the fleet 100, the method comprises a step E30 of collection, by the centralized server 50, of a current value Cur_Q_NOK of the first reliability indicator of the monitoring system calculated by each at least one vehicle of the first set 100.

[0062] In one embodiment, the collection step E30 comprises a transmission by the centralized server of a request intended for at least one selected vehicle 101, 102, 103 from among the vehicles of the first set 100, and a reception by the centralized server 50 of a response from each at least one selected vehicle 101, 102, 103, said response containing a current value Cur_Q_NOK of a first reliability indicator of the monitoring system of the selected vehicle.

[0063] In one embodiment, said response further contains a current value of the following parameters: - a total number of missions N_Tot_M of the selected vehicle, - a total number of missions N_Tot_M_refroid of the selected vehicle including a start-up of the battery cooling system, - a total number of determinations N_refroid_OK_total of a current state of the cooling system as being normal, and - a quotient Q_NOK between, on the one hand, a total number of detections N_refroid_OK by the monitoring system, of a current state of the cooling system as being normal, measured between the instant of first determination T0 and the iteration instant T_iter, and, on the other hand, a number of determinations of a current state of the cooling system as being active, measured between the instant T0 of first determination and the moment of iteration.

[0064] Following the collection step E30, we continue with an evaluation step E40 of the reliability of the supervision system of each at least one selected vehicle comprising: - a sub-step of verifying the relevance of the first reliability indicator transmitted by the at least one selected vehicle, then, - if the reliability indicator is considered irrelevant, an assessment of the reliability of the supervision system as indeterminate, - if the reliability indicator is considered relevant, an assessment of the reliability of the supervision system as being sufficient when the first indicator is equal to 1 with an accuracy of 0.1%, or even 0.01%, or even 0.001%, - otherwise an assessment of the reliability of the supervision system as being insufficient.

[0065] More generally, the precision chosen for the reliability indicator corresponds to a margin of acceptability of false negatives, or false positives. The reliability indicator can take a non-zero value close to 0; this would indicate that the system has detected a few isolated occurrences of a failure of the cooling system among a high number of detections of proper operation of the cooling system. Alternatively, the reliability indicator can take a value very close to 1; this would indicate that the system has detected a few isolated occurrences of proper operation of the cooling system among a high number of detections of a failure of the cooling system.

[0066] In one embodiment, it can be considered for example that below one erroneous detection in a thousand, the robustness of the detection is considered satisfactory.

[0067] The situation in which the reliability indicator is very close to 1 corresponds to a situation where the number N_refroid_NOK is substantially equal to the number N_refroid_actif, which means that from time T0, the cooling system 20 has always been detected as faulty by the monitoring system 30. This situation suggests a permanent failure of the cooling system 20 which would have been detected at time T0, and normal operation of the monitoring system 30.

[0068] According to a fourth situation, the number N_refroid_NOK can be strictly less than the number N_refroid_actif, which means that from the instant T0, the operation of the cooling system 20 has been detected as sometimes faulty and sometimes normal by the monitoring system 30. The fourth situation evokes a failure of the monitoring system 30, the operation of the cooling system 20 being of an indeterminate nature.

[0069] In one embodiment, the sub-step of verifying the relevance of the reliability indicator comprises: - a determination of the reliability indicator of a selected vehicle as irrelevant if the total number of missions of the selected vehicle is zero, or if the total number of missions of the selected vehicle including a start-up of the cooling system is zero, - otherwise a determination of the reliability indicator as being relevant.

[0070] In other words, the reliability indicator of a vehicle monitoring system may be considered relevant only after the vehicle has performed a mission including a start-up of a battery cooling system.

[0071] In one embodiment, the method may comprise, following step E40, a step E50 of interpreting all of the reliability indicators collected.

[0072] Step E50 advantageously comprises methods for statistical processing of the collected reliability indicators. In particular, the fleet 100 comprises a number of vehicles sufficiently high to provide statistically significant results, and thus allow an interpretation of the collected reliability indicators.

[0073] For example, in one embodiment, step E50 may comprise a parameterization of thresholds of the monitoring systems 30 of the vehicles in the fleet, the parameterization of said thresholds having the objective of making the detection of abnormal behavior of the battery cooling system more reliable.

[0074] For example, the settings can relate to: - a detection duration allowing a decision to be made on the ineffectiveness of the cooling, that is to say, in other words, a duration, T_detection, at the end of which we can reliably know whether the cooling is working or not, - a difference between a first cooling fluid temperature stored at the start of the cooling phase, and a second cooling fluid temperature, the second temperature being chosen as a reference to conclude whether the cooling is effective or not, - a difference between the temperature of the cooling fluid and the temperature of the battery cells, after a cooling time at least equal to T_detection, allowing the conclusion to be drawn on the efficiency of the battery cooling; note that the cooling time is adjustable.

[0075] Finally, the method according to the invention makes it possible to reinforce the reliability of monitoring a battery cooling system by using information from a fleet of vehicles.

Claims

Claims

1. Method for evaluating the reliability of a monitoring system (30) of a cooling system (20) of a battery (10) of a motor vehicle from data collected from a first set (100) of vehicles, each vehicle (101, 102, 103) of the first set (100) comprising - a battery (10) equipped with a cooling system (20), - a monitoring system (30) of the cooling system (20) of the battery (10), and - a means of communication (40) with a centralized server (50), characterized in that it comprises: - a first step (E10) of detection, by at least one vehicle of the set (100), of a first fault diagnosis, then - from a time (T0) of first determination of a first fault diagnosis,an iteration on a second step (E20) of determining a first reliability indicator (Cur_Q_NOK) of the monitoring system (30) calculated by each at least one vehicle of the first set (100), and - a third step (E30) of collecting, by the centralized server (50), the current value (Cur_Q_NOK) of the first reliability indicator of each at least one vehicle of the first set (100).,

2. Evaluation method according to the preceding claim, characterized in that the first detection step (E10) comprises: - a sub-step of determining a current state (CUR_S) of the cooling system (20) by the monitoring system (30) of the at least one vehicle (101, 102, 103) as being normal or abnormal, - followed by an iteration on the first step (E10) as long as the current state (CUR_S) of the cooling system (20) is

3.

4.

5. determined to be normal. Evaluation method according to the preceding claim, characterized in that the second step (E20) comprises a sub-step (E21) of setting updated, by the at least one vehicle, of a first reliability indicator of the monitoring system, the first reliability indicator being a quotient (Q_NOK) between, on the one hand, a total number of detections (N_refroid_NOK) by the monitoring system (30) of the at least one vehicle, of a current state of the cooling system as being abnormal, measured between the instant of first determination (T0) and an instant of iteration (T_iter), and on the other hand, a number of determinations (N_refroid_actif) of a current state of the cooling system (30) of the at least one vehicle as being active, measured between the instant (T0) of first determination and the instant of iteration (T_iter). Evaluation method according to the preceding claim, characterized in that the first step (E10) further includes a calculation of the following data: a total number of missions (N_Tot_M) of at least one vehicle, a total number of missions (N_Tot_M_refroid) of the at least one vehicle including a start-up of the cooling system (20) of the battery (10), a total number of determinations (N_cooling_OK_total) of a current state of the cooling system (20) as being normal. Evaluation method according to the preceding claim, characterized in that the second step (E20) further includes a calculation of the following data: a total number of missions (N_Tot_M) of at least one vehicle, a total number of missions (N_Tot_M_refroid) of the at least one vehicle including a start-up of the re- cooling (20) of the battery (10), - a total number of determinations (N_refroid_OK_total) of a current state of the cooling system (20) as being normal, - optionally, a quotient (Q_OK) between i. on the one hand, a total number of detections (N_refroid_OK) by the monitoring system (30), of a current state of the cooling system (20) as being normal, measured between the time of first determination (T0) and the time of iteration (T_iter), and ii. on the other hand, a number of determinations of a current state of the cooling system (20) as being active, measured between the instant (T0) of first determination and the instant of iteration (T_iter).

6. Evaluation method according to one of the preceding claims, characterized in that the collection step (E30) comprises a transmission by the centralized server (50) of a request intended for at least one selected vehicle (101, 102, 103) from among the vehicles of the first set (100), and a reception by the centralized server (50) of a response from each selected vehicle, said response containing a current value of a first reliability indicator of the monitoring system of the selected vehicle.

7. Evaluation method according to claims 5 and 6, characterized in that said response further contains: - a total number of missions (N_Tot_M) of the selected vehicle, - a total number of missions (N_Tot_M_refroid) of the selected vehicle including a start-up of the battery cooling system, - a total number of determinations (N_refroid_OK_total) of a current state of the cooling system as normal, and - a quotient between i. on the one hand, a total number of detections (N_refroid_OK) by the monitoring system, on the other current state of the cooling system as normal, measured between the time of first determination (T0) and the time of iteration (T_iter), and ii. on the other hand, a number of determinations of a current state of the cooling system as active, measured between the time (T0) of first determination and the time of iteration.

8. Evaluation method according to the preceding claim, characterized in that it comprises, following the collection step (E30), a step of evaluation (E40) of a reliability of the supervision system of each at least one selected vehicle comprising: - a sub-step of verification of a relevance of the first reliability indicator (Q_NOK) transmitted by the at least one selected vehicle, then, - if the first reliability indicator (Q_NOK) is considered as irrelevant, an evaluation of the reliability of the supervision system as being indeterminate, - if the first reliability indicator (Q_NOK) is considered as relevant, an evaluation of the reliability of the supervision system as being sufficient when the first indicator is equal to 1 with an accuracy of 0.1%, or even 0.01%, or even 0.001%, - otherwise an evaluation of the reliability of the supervision system as being insufficient.

9. Evaluation method according to the preceding claim, characterized in that the sub-step of verifying a relevance of the first reliability indicator comprises: - a determination of the first reliability indicator (Q_NOK) of a selected vehicle as not relevant if the total number of missions of the selected vehicle (N_Tot_M) is zero, or if the total number of missions of the selected vehicle comprising a start-up of the cooling system (N_Tot_M_refroid) is zero, or if the number of detections, by the monitoring system (30), of a current state of the cooling system (20) as being abnormal is zero, - otherwise a determination of the first reliability indicator as being relevant.

10. Motor vehicle (101, 102, 103) characterized in that it comprises the hardware means (10, 11, 12, 20, 21, 30, 31, 40, 60, 61) and software for implementing the steps of the evaluation method according to one of the preceding claims.

11. Device (60) for evaluating the reliability of a monitoring system (30) of a cooling system (20) of a battery (10) of a motor vehicle (101, 102, 103), the motor vehicle (101, 102, 103) being equipped with a battery (10), a cooling system (20) of the battery (10), a monitoring system (30) of the cooling system of the battery, and a means of communication (40) with a centralized server (50), the device comprising hardware and / or software elements (11, 12, 21, 31, 60, 61) implementing the method according to one of claims 1 to 9.

12. A computer program product comprising program code instructions recorded on a computer-readable medium for implementing the steps of the method according to any one of claims 1 to 9 when said program is running on a computer.

13. A computer-readable data storage medium on which is recorded a computer program comprising program code instructions for implementing the method according to one of claims 1 to 9.