METHOD FOR DETECTING THE IMMOBILIZATION OF A RECHARGEABLE MOTOR VEHICLE PRIOR TO A CRITICAL DEEP DISCHARGE OF A TRACTION BATTERY OF SAID VEHICLE

Abstract

The invention relates to a method for detecting the immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle, comprising a step of recording a charging stop date DCfin(n); a step of recording a charging start date DCinit(n+1) when a charging device is inserted into the charging base; a step of calculating a first time interval IntD between the charging stop date DCfin(n) and the charging start date DCinit(n+1) using the following mathematical formula: IntD = DCinit(n+1) – DCfin(n), the first time interval IntD being stored in said intelligent control unit; or a step of recording a current date Dactu at which the battery is in critical deep discharge, a second time interval IntDactu being calculated using the following mathematical formula: IntDactu = Dactu – DCfin(n). Figure 1

Description

Title of the invention: DETECTION METHOD OF AN IMMOBILIZATION OF A RECHARGEABLE MOTOR VEHICLE PRIOR TO A CRITICAL DEEP DISCHARGE OF A TRACTION BATTERY OF SAID VEHICLE

[0001] The invention relates to the recharging of batteries in rechargeable motor vehicles.

[0002] Prior art patent application FR3020614 is known, describing a method for monitoring a vehicle's electric battery to prevent or remedy vehicle immobilization in the event of a starting failure. The objective is to assist mechanics in making decisions regarding battery problems and to inform the driver. The method consists of periodically measuring the battery's state of charge and comparing the various measured values ​​to a predetermined threshold value. The number of measured values ​​below this predetermined threshold value is counted. This information allows a decision to be made as to whether or not the battery needs to be replaced. Furthermore, a device is described. The device includes means for measuring the battery's state of charge at regular intervals and means for comparing these values. However, a drawback remains.Indeed, the need to replace a battery can be caused by a defective module or cell, improper battery installation, or poor battery maintenance. Therefore, responsibility may lie with the battery module and / or cell supplier, the vehicle manufacturer, or the vehicle user, respectively. However, the method described in patent application FR3020614, and the associated device, are not capable of determining the origin of battery malfunctions.

[0003] The objective of the present invention is to remedy these drawbacks and to determine whether the anomaly was caused by a prolonged immobilization of the vehicle during which the battery of said vehicle was not recharged.

[0004] To achieve this objective, the invention proposes a method for detecting the immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle, the vehicle comprising a charging base configured to accommodate a means for recharging said battery, the battery having an actual state of charge, the actual state of charge being the amount of available energy stored in said battery, the critical deep discharge being characterized by a zero actual state of charge, the battery comprising a battery management system configured to measure the actual state of charge of said battery and to detect said charging means in said charging base, the vehicle comprising a powertrain including a supervisor configured to communicate with the battery management system, said vehicle comprising an intelligent service box configured to centralize the electronic information of said vehicle, notable in that said method comprises the following steps: - a step of recording a DCfin(n) charging stop date, the charging stop date being the last date on which the battery charging ends; - a step of recording a DCinit(n+l) charging start date when a charging means is plugged into the charging base; - a step of calculating a first time interval IntD between the date of stopping the charge DCfin(n) and the date of starting the charge Dcinit(n+1) by the following mathematical formula: IntD = Dcinit(n+1) - DCfin(n), the first time interval IntD being stored in said intelligent servicing box, the immobilization of the vehicle being detected when the first time interval IntD is greater than a predetermined threshold value or a step of recording a current date Dactu at which the battery is in critical deep discharge, a second time interval IntDactu being calculated by the following mathematical formula: IntDactu = Dactu -DCfin(n), the immobilization of said vehicle being detected when the second time interval IntDactu is greater than the predetermined threshold value.

[0005] Thanks to the invention, the operator controlling the vehicle following the entry of the battery into critical deep discharge is able to know whether the vehicle has been immobilized for a prolonged period of time or not.

[0006] Advantageously, said method includes a step of generating a fault code by the battery management system when the first time interval IntD or the second time interval IntDactu is greater than the predetermined threshold value.

[0007] Thus, the operator knows if the vehicle has been immobilized for a long period of time without having to note the precise date of the last battery recharge.

[0008] Advantageously, said predetermined threshold value is greater than 20 days.

[0009] Advantageously, during said generation step, the number of fault codes generated is counted and recorded by said battery management system.

[0010] This makes it possible to know if the vehicle, although it did not immediately enter critical deep discharge, has undergone several immobilizations.

[0011] Preferably, the steps of said process are carried out by the battery management system, by the powertrain supervisor or by the intelligent service box.

[0012] The invention also relates to a computer program comprising instructions which, when the program is executed by a computer, lead the latter to implement the steps of the method for detecting an immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle previously described.

[0013] Furthermore, the invention relates to a rechargeable motor vehicle configured to implement the method of detecting an immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle previously described.

[0014] The invention will be further detailed by the description of a non-limiting embodiment, and on the basis of the attached figure illustrating the invention, in which [Fig.1] schematically illustrates, in the form of a logic diagram, a method for monitoring the periods of electrical recharging of a traction battery of a rechargeable motor vehicle.

[0015] A method for detecting the immobilization of a rechargeable motor vehicle prior to a critical deep discharge of its traction battery is schematically illustrated in Figure 1 in the form of a flowchart. For example, the vehicle may be electric or hybrid. The vehicle may also include a fuel cell. The battery comprises a plurality of modules containing cells. Furthermore, the vehicle includes a charging base configured to accommodate a charging device for recharging the battery. The battery displays a state of charge and an actual state of charge. The displayed state of charge is the battery's charge level, which is communicated to the driver to estimate the vehicle's range and, if necessary, to schedule an electrical recharge of the vehicle's battery.The battery includes a battery management system configured to detect when the charging device is inserted into the charging port and to measure the battery's actual state of charge. For example, the displayed state of charge may appear on the vehicle's instrument panel. The actual state of charge is the actual amount of energy the battery is capable of delivering. After a full charge, the displayed state of charge is 100%. However, the actual state of charge is less than 100%. For example, for a new vehicle, the actual state of charge is 97%, while for a vehicle with 200,000 km on the odometer, the actual state of charge is 88%. When the battery is discharged, the displayed state of charge is 0%, while the actual state of charge is 1%. When the actual state of charge reaches 0%, it means the battery is in a critically deep discharge.In most cases of critical deep discharge, it is impossible to recharge the battery. Therefore, it is necessary to replace it. The vehicle's battery. Critical deep discharge can be caused by a defect in the battery cells or cell modules, improper battery installation in the vehicle, or prolonged vehicle inactivity. In fact, the battery's actual state of charge gradually decreases even when the vehicle is stationary. Thus, it is possible for the vehicle's actual state of charge to reach 0% without the vehicle having been used for an extended period. Replacing the vehicle's battery is expensive; therefore, it is necessary to determine the cause of the critical deep discharge in order to assign responsibility to the battery cell or module supplier, the vehicle manufacturer, or the vehicle owner, respectively.The vehicle includes a powertrain comprising a supervisor configured to communicate with the battery management system, also known as the BMS (Battery Management System). In addition, the vehicle includes a smart junction box configured to centralize the vehicle's electronic information.

[0016] During a step that records a DCfin(n) charging stop date, the date on which battery charging ends is recorded. This is therefore the date of the last battery charging completion. Only the last DCfin(n) charging stop date is recorded. Optionally, all DCfin(n) charging stop dates are recorded to create a history. During a step that records a DCinit(n+1) charging start date, the date on which the vehicle owner attempts to charge the vehicle battery by plugging the charging device into the vehicle's charging port is recorded. The charging device is, for example, an electric charging cable gun configured to be connected to a wall outlet or an electric charging station.During a calculation step, an initial time interval IntD between the charging stop date DCfin(n) and the charging start date Dcinit(n+1) is calculated using the following mathematical formula: IntD = Dcinit(n+1) - DCfin(n). This initial time interval IntD is stored in the intelligent control unit. Vehicle immobilization is detected when this initial time interval IntD exceeds a predetermined threshold value. Therefore, when the vehicle owner brings the vehicle to a garage for inspection, an operator can determine the date of the last charging attempt, i.e., the charging start date DCinit(n+1), as well as the initial time interval IntD that elapsed between the last charging attempt (DCfin(n)) and the charging attempt (DCinit(n+1)).From this information, it is possible to determine if the battery has entered a critical deep discharge due to prolonged immobilization, and therefore to an absence. of battery charging for an excessive period of time. Or, during a step of recording a current date Dactu, the current date Dactu corresponds to the date on which the actual state of charge measured by the battery management system is zero, i.e., the date on which the battery is in critical deep discharge. A second time interval is calculated using the following mathematical formula: IntDactu = Dactu - DCfin(n). Vehicle immobilization is detected when the second time interval IntDactu is greater than the predetermined threshold value. When the battery is in critical deep discharge, the battery management system may no longer be able to detect the charging device plugged into the charging socket.In this case, the operator still has access to the time interval between the last charge, i.e., between the charge completion date DCfin(n), and the current date Dactu at which the operator is monitoring the vehicle. In other words, the operator has access to the second time interval IntDactu. From this information, the operator can deduce whether the battery has entered a critical deep discharge due to prolonged vehicle immobilization or not. All the steps of the process are preferably carried out by the battery management system. However, the steps can also be carried out by the powertrain supervisor or the intelligent service box. Furthermore, the procedure may include an optional step where the battery management system generates a fault code when either the first IntD time interval or the second IntDactu time interval exceeds a predetermined threshold value. This predetermined threshold value varies depending on the battery type, as some batteries are less prone to entering critical deep discharge than others. Preferably, the predetermined threshold value is greater than 20 days. The fault code is logged so that the operator monitoring the vehicle can determine if the vehicle has been immobilized for a period exceeding the predetermined threshold value without having to check the dates. This also provides additional evidence should the garage wish to hold the vehicle owner liable.Furthermore, it is possible to count and record the number of fault codes generated throughout the battery's lifespan. All fault codes are recorded by the battery management system. Thus, when the battery is installed in the vehicle, the battery management system displays 0 fault codes. Each time a fault code is generated during the generation process, the fault code count is incremented by 1. This allows the operator to check if the vehicle owner is leaving the vehicle parked too frequently, which reduces the battery's lifespan. Additionally, when the battery is replaced, the fault code count is reset to 0 in the battery management system.

[0017] Furthermore, the invention relates to a computer program configured to implement the aforementioned method for monitoring the battery's electrical recharging periods. The invention also relates to a rechargeable motor vehicle configured to implement the aforementioned method.

Claims

1. Demands Method for detecting the immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle, the vehicle comprising a charging base configured to accommodate a means of charging said battery, the battery having an actual state of charge, the actual state of charge being the amount of available energy stored in said battery, the critical deep discharge being characterized by a zero actual state of charge, the battery comprising a battery management system configured to measure the actual state of charge of said battery and to detect said charging means in said charging base, the vehicle comprising a powertrain comprising a supervisor configured to communicate with the battery management system, said vehicle comprising an intelligent service box configured to centralize the electronic information of said vehicle,characterized in that said process comprises the following steps: - a step of recording a DCfin(n) charge stop date, the charge stop date being the last date on which the battery charging ends; - a step of recording a start date of the DCinit(n+l) charge when a reloading means is plugged into the reloading base; - a step of calculating a first time interval IntD between the date of stopping the charge DCfin(n) and the date of starting the charge DCinit(n+l) by the following mathematical formula: IntD = DCinit(n+l) - DCfin(n), the first time interval IntD being stored in said intelligent servicing box, the immobilization of the vehicle being detected when the first time interval IntD is greater than a predetermined threshold value or a step of recording a current date Dactu at which the battery is in critical deep discharge, a second time interval IntDactu being calculated by the following mathematical formula: IntDactu = Dactu - DCfin(n), the immobilization of said vehicle being detected when the second time interval IntDactu is greater than the predetermined threshold value.

2. A method according to claim 1 characterized in that said method comprises a step of generating a fault code by the battery management system when the first time interval IntD or the second time interval IntDactu is greater than the predetermined threshold value.

3. A method according to claim 1 or 2 characterized in that said predetermined threshold value is greater than 20 days.

4. A method according to claim 2 or 3 characterized in that, during said generation step, the number of fault codes generated is counted and recorded by said battery management system.

5. A method according to any one of claims 1 to 4 characterized in that the steps of said method are carried out by the battery management system, by the powertrain supervisor or by the intelligent service box.

6. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to implement the steps of the method for detecting an immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle according to any one of claims 1 to 5.

7. Rechargeable motor vehicle configured to implement the method of detecting an immobilization of a rechargeable motor vehicle prior to a critical deep discharge of a traction battery of said vehicle according to any one of claims 1 to 5.

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