METHOD FOR ENERGY MANAGEMENT OF AN ACCESSORY POWER OUTLET IN A STATIONARY MOTOR VEHICLE

Abstract

The method is implemented in a vehicle in which the vehicle's electrical system includes a low-voltage electrical storage unit and an accessory socket (AS) connected to it. With the vehicle stationary, the method comprises dynamically determining the permissible operating time (DAmax_PA) of the storage unit to supply a load connected to the accessory socket. This permissible operating time is determined based on at least one detected vehicle operating condition that affects the energy state of the electrical system. A decision is then made, based on the permissible operating time, to allow (E12V_PA, DM_eVCU) power to the load connected to the accessory socket from the electrical system. Fig. 1

Description

Title of the invention: METHOD FOR ENERGY MANAGEMENT OF AN ACCESSORY POWER OUTLET IN A STATIONARY MOTOR VEHICLE

[0001] The invention relates generally to the field of energy management of an on-board electrical network in a motor vehicle. More particularly, the invention relates to a method for managing the energy of an accessory power outlet in a stationary motor vehicle. The invention is applicable particularly, but not exclusively, to an electric vehicle.

[0002] Motor vehicles include in their passenger compartment one or more accessory power outlets connected to their low-voltage, typically 12 V, on-board electrical system, to which an accessory, such as a smartphone, can be connected for charging. The accessory power outlet, also referred to hereafter as the "accessory outlet," is usually an ISO4166 type outlet, known as a "cigarette lighter" outlet, or a "USB" type outlet (for "Universal Serial Bus").

[0003] When the vehicle is stationary, with the vehicle's electrical system generator inactive, the user is generally able to use the accessory socket, for example, to power their smartphone or another electrical device compatible with a 12V power supply. In a conventional internal combustion engine vehicle, the vehicle's 12V electrical storage system supplies power to the accessory plugged into the socket, and when the vehicle is stationary, this storage system will undergo a significant discharge if the socket is used for an extended period. The same will be true in an electric vehicle if it is stationary and not connected to a charging station to recharge its high-voltage electrical storage system.Otherwise, when the vehicle is connected to a charging station, the vehicle's DC-DC converter, acting as the electrical generator for the on-board electrical system, will generally be active and will then supply electrical power for the accessory connected to the socket and for a supplementary charge to the 12V electrical storage unit if necessary.

[0004] The 12V electrical storage unit of the vehicle's electrical system is a critical component, as it generally provides the electrical energy required for the vehicle's power-up and starting sequence, supplying power to all of its control units. It is therefore important to prevent excessive discharge of the 12V electrical storage unit by avoiding prolonged use of the accessory socket when the vehicle is stationary, even when information Information related to the energy storage system, such as its state of charge (SOC), temperature, and other parameters, is inaccessible. Indeed, without this information, the vehicle could fail to start, as the 12V energy storage system would be unable to supply the necessary electrical energy for the vehicle's starting sequence.

[0005] It is therefore desirable to propose an energy management method for an accessory socket in a stationary motor vehicle, designed to regulate the availability of the electrical supply function provided by the socket so as to maintain a sufficient state of charge of the electrical storage of the vehicle's on-board electrical network and thus avoid a failure to start the vehicle.

[0006] The invention relates to a method for managing the energy of an accessory power outlet in a vehicle, the accessory power outlet being connected to a vehicle on-board electrical network comprising a low-voltage electrical storage unit, the method comprising, when the vehicle is stationary, a dynamic determination of an authorized usage time of the electrical storage unit to power a consumer device connected to the accessory power outlet, the authorized usage time being determined according to at least one detected vehicle life situation which affects an energy state of the low-voltage on-board electrical network, and a decision to allow or not a power supply from the vehicle on-board electrical network of the consumer device connected to the accessory power outlet which is taken according to the authorized usage time.

[0007] According to a particular feature, the method includes, when the vehicle is stationary, a comparison between a state of charge of the electrical storage unit and a calibrated state of charge threshold, and the decision to allow or not a supply by the vehicle's on-board electrical network of the consumer device connected to the accessory power supply socket is also taken according to the result of the aforementioned comparison.

[0008] According to another particular feature, the state of charge threshold is calibrated according to a temperature of the electrical storage.

[0009] According to yet another particular feature, the method includes a detection, when said vehicle is stationary, of an activation of a voltage converter supplying energy to the vehicle's on-board electrical network, and the decision to allow or not a supply by the vehicle's on-board electrical network of the consumer device connected to the accessory power supply socket is also taken according to the result of the aforementioned detection.

[0010] According to yet another particular feature, the process includes the detection of a first life situation which is an activation phase of the voltage converter for at least an initial calibrated duration when the vehicle is stopped.

[0011] According to yet another particular feature, the method includes a detection of a second life situation which is a vehicle phase started for at least a second calibrated duration before the vehicle stopped.

[0012] According to yet another particular feature, the method includes a detection of a third life situation which is an electrical consumption through the accessory power supply socket outside of the first and second life situations, and a periodic decrement of the authorized usage time during the detected third life situation.

[0013] According to yet another particular feature, the method includes an initialization of the authorized usage time to a maximum value when the first life situation is detected and / or the second life situation is detected.

[0014] The invention also relates to a computer comprising a memory storing program instructions for implementing the method as briefly described above. The invention also relates to a vehicle comprising a computer as indicated above.

[0015] Other advantages and features of the present invention will become more apparent upon reading the detailed description below of a particular embodiment of the invention, with reference to the accompanying drawings, in which:

[0016] [Fig-1] The [Fig.1] is a block diagram showing different functions of a treatment process carried out for the implementation of the process according to the present invention.

[0017] [Fig.2] Fig.2 is a logic diagram of a first function executed by the treatment process implementing the method according to the present invention.

[0018] [Fig. 3 Fig. 3 is a logic diagram of a second function executed by the treatment process implementing the method according to the present invention.

[0019] [Fig.4] Fig.4 is a logic diagram of a third function executed by the treatment process implementing the method according to the present invention.

[0020] [Fig.5] Fig.5 is a logic diagram of a fourth function executed by the treatment process implementing the method according to the present invention.

[0021] With reference to Figs. 1 to 5, a particular embodiment of the method according to the invention is now described below in the context of an application to an electric vehicle.

[0022] With particular reference to Fig. 1, the method according to the invention is implemented in the vehicle by means of an ESW embedded software module. In this embodiment, the ESW embedded software module is implemented in an ECU_12V supervisory computer of the vehicle's on-board electrical network, more specifically in a MEM memory of this computer. For the implementation of the invention, the ECU_12V supervisor computer is required to cooperate, under the supervision of the ESW software module, with the vehicle's main eVCU and possibly with other vehicle computers via a BCD data communication network, typically of the "CAN" type. In other embodiments, the ESW software module may be hosted in a vehicle computer separate from the ECU_12V supervisor computer, such as, for example, the aforementioned main eVCU or a computer (not shown) of a battery management system, known as a "BMS" for "Battery Management System".

[0023] The ESW software module enables the implementation of the method according to the invention by the execution of program code instructions by a processor (not shown) of the supervisor ECU_12V computer, in which the ESW module is hosted in this example embodiment.

[0024] The ECU_12V supervisory computer also hosts various vehicle on-board electrical network supervision strategies, which are implemented by one or more SUP12V embedded software modules, referred to hereinafter as "SUP12V supervisory module".

[0025] As shown schematically in [Fig.1], in this embodiment example, the ESW software module is in direct communication with the SUP12V supervisor module via a software interface (not shown) and in indirect communication with the eVCU main computer via the SUP12V supervisor module and the BCD data communication network.

[0026] In the vehicle, the power supply to the accessory sockets PA is established via a switch SW, which is controlled to open / close by a command C_PA. The state of this command is determined by the main control unit eVCU. When the main control unit eVCU is activated, the C_PA command is itself in an active state, which closes the switch SW. The closed switch SW supplies electrical power to the accessory sockets PA, which are then able to perform their function of powering the connected accessories. When the vehicle is stationary and a need for electrical power through an accessory socket PA is detected, if the necessary conditions are met, the ESW software module process wakes up the main control unit eVCU to cause the power switch SW to close, by switching the C_PA command to an active state, and thus supply power to the accessory sockets PA.The waking up and / or maintaining the eVCU in an active state is controlled by the ESW software module process via a DM_eVCU activation request for the eVCU, which is established according to the method of the invention. In this embodiment, the request... The activation of the main control unit DM_eVCU is transmitted to the eVCU control unit via the SUP12V supervisor module and the BCD data communication network.

[0027] As shown in [Fig. 1], the SUP12V supervisor module receives SOC_B and TEMP_B status information relating to the STK12V low-voltage electrical storage device from the vehicle's electrical system and transmits this information to the ESW module for use in its processing, detailed below. SOC_B information represents the evaluated state of charge of the STK12V electrical storage device, and TEMP_B information represents the measured temperature of the STK12V electrical storage device. SOC_B and TEMP_B information are typically transmitted to the SUP12V supervisor module by a battery management system (BMS) (not shown) via a data communication link, for example, a Local Interconnect Network (LIN) type.

[0028] In general, the processing carried out by the SW software module and implementing the method of the invention performs in particular the actions briefly described below.

[0029] First, when the vehicle's PA accessory power supply functions are requested by the user, for example, to charge their smartphone via a vehicle USB PA port, the process keeps the vehicle's eVCU main control unit active and reports that the eVCU remains awake. The eVCU's continued activity and the resulting power supply to the PA accessory sockets are managed by the process through the aforementioned DM_eVCU main control unit activation request. To define the state of the DM_eVCU main control unit activation request, the process dynamically calculates an authorized usage time for the PA accessory power supply functions, in order to control the discharge of the STK12V electrical storage unit when the vehicle is stationary.

[0030] For the calculation of the authorized usage time of the power supply functions via the PA accessory sockets, the process takes into account the possibility of using the electrical energy supplied by the public electrical network via a charging station to which the vehicle is connected, so as to increase the availability for the user of these power supply functions via the PA accessory sockets.

[0031] During a life phase where the vehicle is stationary, the process evaluates an energy state of the system ensuring the supply of low voltage (12 V) electrical energy to the vehicle, integrating the possible energy input through a charging station, to define the state of the activation request of the main computer DM_eVCU and allow or not a discharge of the STK12V electrical storage for the electrical supply functions via the PA accessory sockets.

[0032] As can be seen in [Fig. 1], the processing of the ESW software module essentially comprises four functions Fl to F4 for implementing the method according to the invention. The functions Fl to F4 are described in detail below with reference to Figs. 1 to 5. In the flowcharts of Figs. 2 to 5, a satisfied condition, an active command, true information, or a nominal state is represented by an "OK" state, while an unsatisfied condition, an inactive command, false information, or a degraded state is represented by a "NOK" state.

[0033] With reference to Figs. 1 and 2, the Fl function is responsible for establishing the activation request for the main control unit DM_eVCU according to the vehicle's operating status. The Fl function receives as input a BA_PA signal representing a power requirement on an accessory connector PA and an E12V_PA signal representing the energy status of the system providing low-voltage (12 V) electrical power. The Fl function outputs the activation request for the main control unit DM_eVCU. The BA_PA power requirement signal is typically provided by the SUP12V supervisor module hosted by the ECU-12V supervisor control unit, which manages the vehicle's electrical network, but it can also originate from a vehicle control unit other than the ECU_12V supervisor control unit via the BCD data communication network.The power demand information BA_PA is active, BA_PA = "OK", when a power demand has been detected following the connection of an electrical load by the user to an accessory outlet PA, and is inactive, BA_PA = "NOK", otherwise. The energy status information E12V_PA is active, E12V_PA = "OK", when the low-voltage power supply system is in a nominal state, and is inactive, E12V_PA = "NOK", when the low-voltage power supply system is in a degraded state. When the energy status information E12V_PA is active, E12V_PA = "OK", the discharge of the STK12V energy storage device can be authorized by the process for powering an electrical load through the accessory outlets PA. The energy status information E12V_PA is generated by the function F4, which will be described below with particular reference to the flowchart in [Fig. 5]. .

[0034] As shown in the flowchart of [Fig. 2], functional blocks B1 to B4 cooperate to establish the activation request for the main control unit DM_eVCU based on the information BA_PA and E12V_PA. Functional block B1 activates an output Y when the power requirement information BA_PA is in the active state, BA_PA = "OK", and activates an output N otherwise, when the power requirement information BA_PA is in the inactive state, BA_PA = "NOK". Functional block B2 activates an output Y when the energy status information E12V_PA indicates a nominal energy state, E12V_PA = "OK", and activates an output N in Otherwise, when the energy status information E12V_PA indicates a degraded energy state, E12V_PA = "NOK". The AND logic function B3 delivers the activation request for the main control unit DM_eVCU in the active state, DM_eVCU = "OK", when both "Y" outputs of function blocks B1 and B2 are active. The OR logic function B4 delivers the activation request for the main control unit DM_eVCU in the inactive state, DM_eVCU = "NOK", when at least one of the two "N" outputs of function blocks B1 and B2 is active.

[0035] With reference to Figs. 1 and 3, function F2 is responsible for confirming power consumption on an accessory socket PA, which is likely to cause discharge of the STK12V power storage device. To this end, function F2 outputs a power consumption signal CONS 12V, which is active, CONS12V = "OK", when power consumption is actual, and inactive, CONS 12V = "NOK", otherwise. The power consumption signal CONS 12V is established from the activation request of the main control unit DM_eVCU, which indicates, in active state, DM_eVCU = "OK", that the main control unit eVCU is kept awake and therefore that power consumption is in progress on an accessory socket PA.

[0036] As seen in [Fig.1], the electrical consumption information CONS12V is provided as input to the function F3 described below in the description.

[0037] As shown in the flowchart of [Fig. 3], a function block B5 receives as input the main control unit activation request DM_eVCU and outputs the power consumption information CONS 12V. Function block B5 activates an output Y which validates the power consumption information CONS 12V = "OK" when the main control unit activation request DM_eVCU is active, DM_eVCU = "OK". Function block B5 activates an output N which validates the power consumption information CONS 12V = "NOK" when the main control unit activation request DM_eVCU is inactive, DM_eVCU = "NOK".

[0038] With reference now more specifically to Figs. 1 and 4, function F3 is responsible for dynamically assigning and updating an authorized usage time DAmax_PA for the STK12V electrical storage unit to power a consumer device connected to an accessory socket PA when the vehicle is stationary. Function F3 specifically ensures the energy protection of the STK12V electrical storage unit against excessive discharges, even when it is not possible to know the storage unit's state of charge. Indeed, as will become clear from the description of function F4 below, once the authorized usage time DAmax_PA has expired, the energy status information E12V_PA switches to its degraded state, E12V_PA = "NOK", thus preventing the main control unit eVCU from waking up and therefore the use of the accessory sockets PA.

[0039] Function F3 receives as input DCDC_ST voltage converter status information indicating the active or inactive state of the vehicle's voltage converter, DR_CY vehicle start / stop information indicating whether the vehicle is in a started phase, and the aforementioned CONS 12V power consumption information, and outputs the maximum permissible operating time DAmax_PA. The DCDC_ST voltage converter status information and the DR_CY vehicle start / stop information are typically provided by the SUP12V supervisor module or may originate from a vehicle control unit other than the ECU_12V supervisor module, via the BCD data communication network.

[0040] As can be seen in the flowchart of [Fig.4], the function F3 essentially comprises three sub-functions BK0, BK1 and BK2.

[0041] The sub-function BK0 is a counter that provides the current value of the allowed usage time DAmax_PA.

[0042] The counter BK0 can be initialized to a maximum duration value DMAX (DAmax_PA = DMAX), for example, 30 minutes (min). The sub-function BK1 is responsible for managing the initialization of the duration DAmax_PA = DMAX in the counter BK0.

[0043] With the vehicle stationary, when the power supply to a consumer via an accessory socket PA is provided by the STK12V power storage device, the duration DAmax_PA in the BK0 counter is periodically decremented until it eventually reaches a value of zero, DAmax_PA = "0", which will terminate the use of the STK12V power storage device for this power supply. Thus, for example, the duration DAmax_PA can be decremented by one (1), DAmax_PA = DAmax_PA - 1, every DD seconds, with DD = 1 s. This decrement of the duration DAmax_PA in the BK0 counter is managed by the BK2 sub-function.

[0044] The sub-functions BK1 and BK2 are now described above.

[0045] As seen in [Fig.4], the sub-function BK1 essentially comprises two functional modules BK10 and BK11 which cooperate with a logic function B16 of type "AND" to manage the initialization of the counter BK0 to the duration DAmax_PA = DMAX.

[0046] The BK10 functional module essentially comprises the functional blocks B6 to B12. This BK10 functional module detects life situations in which the STK12V electrical storage unit has potentially been charged following a vehicle start phase or has been charged following an activation of the vehicle's voltage converter.

[0047] Functional blocks B6 to B8 detect the life situation in which the vehicle transitions from a started vehicle phase to a stationary vehicle phase and the The vehicle's voltage converter is inactive because the vehicle is not connected to a charging station. Function block B6 processes the vehicle start / stop information DR_CY to detect the transition from the vehicle started state, DR_CY = "OK", to the vehicle stopped state, DR_CY = "NOK". Function block B6 activates a Y output when the transition from DR_CY = "OK" to DR_CY = "NOK" is detected and, otherwise, activates an N output for a wait loop. Function block B7 processes the voltage converter status information DCDC_ST to detect the voltage converter's inactivity, DCDC_ST = "NOK". Function block B7 activates a Y output when the condition DCDC_ST = "NOK" is met and, otherwise, activates an N output for a wait loop. The Y outputs of function blocks B6 and B7 are provided as inputs to the AND logic gate B8.When both Y outputs of functional blocks B6 and B7 are active, the AND type logic gate B8 delivers, through the OR type logic gate B12, a first condition validation output DC1 to an active state which is applied to a first input of the AND type logic gate B16.

[0048] Functional blocks B9 to B11 detect the life situation in which the vehicle is stopped and the vehicle's voltage converter goes from an active state to an inactive state, which means that a recharge of the STK12V electrical storage has taken place.

[0049] Function block B9 processes the vehicle start / stop information DR_CY to detect a stopped state, DR_CY = "NOK", of the vehicle. Function block B9 activates an output Y when the condition DR_CY = "NOK" is met and, otherwise, activates an output N for a wait loop. Function block B10 processes the voltage converter status information DCDC_ST to detect a transition of the voltage converter from an active state, DCDC_ST = "OK", to an inactive state, DCDC_ST = "NOK". Function block B10 activates an output Y when the transition from DCDC_ST = "OK" to DCDC_ST = "NOK" is detected and, otherwise, activates an output N for a wait loop. The outputs Y of function blocks B9 and B10 are provided as input to the AND logic gate B11.When both Y outputs of function blocks B9 and B10 are active, the AND logic gate B11 delivers, through the OR logic gate B12, the first condition validation output DC1 in the active state, which is applied to the first input of the AND logic gate B16 as described above.

[0050] The BK11 functional module has the function of confirming a sufficient charging time of the STK12V electrical storage unit following a vehicle start phase or an activation phase of the vehicle's voltage converter by connection to a charging station.

[0051] The BK11 functional module essentially comprises the functional blocks B13 to B15. This BK11 functional module is responsible for detecting two life situations, namely, a first situation in which a vehicle started phase, with a subsequent recharging of the STK12V electrical storage, has occurred for a determined duration and a second situation in which the activation of the vehicle's voltage converter, with a subsequent recharging of the STK12V electrical storage, has occurred for a determined duration.

[0052] Function block B13 detects the first life situation mentioned above. Function block B13 processes the vehicle start / stop information DR_CY to detect a vehicle start phase, DR_CY = "OK", having at least a calibrated duration DminR12V equal to, for example, 5 minutes. Function block B13 activates an output Y when the condition DR_CY = "OK" for at least the duration DminR12V is satisfied and, otherwise, activates an output N for a wait loop. Function block B14 detects the second life situation mentioned above. Function block B14 processes the voltage converter status information DCDC_ST to detect a voltage converter activation phase, DCDC_ST = "OK", having at least the calibrated duration DminR12V. Function block B14 activates an output Y when the condition DCDC_ST = "OK" for at least the duration DminR12V is satisfied and, otherwise, activates an output N for a wait loop.The Y outputs of function blocks B13 and B14 are provided as input to the OR logic gate B15. The OR logic gate B15 provides a second condition validation output DC2 which is applied to a second input of the AND logic gate B16. The second condition validation output DC2 is active when at least one of the Y outputs of function blocks B13 and B14 is active.

[0053] When the first and second condition validation outputs DC1 and DC2, delivered respectively by the functional modules BK10 and BK11, are active, the logic gate B16 of type "AND" provides as output an INIT counter initialization command to the active state which sets the authorized usage time DAmax_PA to DMAX, DAmax_PA = DMAX.

[0054] As shown in [Fig. 4], the BK2 sub-function essentially comprises four functional blocks B18 to B21 which cooperate to establish a counter decrement command DEC. The DEC command is provided to the BKO counter for decrementing the authorized usage time DAmax_PA. In the management performed by the BK2 sub-function, the authorized usage time DAmax_P is decremented when electrical consumption occurs while the vehicle's voltage converter is not active and the vehicle is stationary. In other words, when the power supply via an accessory PA socket, vehicle stationary, is provided by the STK12V electrical storage unit.

[0055] Function block B18 processes the vehicle start / stop information DR_CY to detect a stopped phase, DR_CY = "NOK", of the vehicle. Function block B18 activates an output Y when the condition DR_CY = "NOK" is met and, otherwise, activates an output N for a standby loop. Function block B19 processes the voltage converter status information DCDC_ST to detect an idle phase, DCDC_ST = "NOK", of the vehicle's voltage converter. Function block B19 activates an output Y when the condition DCDC_ST = "NOK" is met and, otherwise, activates an output N for a standby loop. Function block B20 processes the power consumption information CONS 12V to detect power consumption via an accessory socket PA. Function block B20 activates a Y output when the condition CONS 12V = "OK" is met and, otherwise, activates an N output for a wait loop.The Y outputs of function blocks B18, B19, and B20 are provided as input to the AND logic gate B21. When all three Y outputs of function blocks B18, B19, and B20 are active, the AND logic gate B21 delivers an active counter decrement command DEC, which causes a decrementing reduction of the allowed usage time DAmax_PA in the counter B KO.

[0056] With reference now more particularly to Figs. 1 and 5, the function F4 is responsible for establishing and delivering the aforementioned energy state information E12V_PA, for use by the function FL. To establish the energy state information E12V_PA, the function F4 uses the aforementioned DCDC_ST voltage converter state information, as well as the state information of the STK12V electrical storage, namely, the aforementioned SOC_B charge state information and TEMP_B temperature information, and the authorized usage time DAmax_PA determined by the function F3.

[0057] As can be seen in the flowchart of [Fig.5], functional blocks B22 to B27 cooperate to produce the energy state information E12V_PA.

[0058] When the vehicle's voltage converter is active, which is the case when the vehicle is stationary and connected to a charging station, the converter is able to supply electrical power to the vehicle's electrical network. In this operating condition, the risk of discharging the 12V storage unit through the use of the PA accessory sockets is limited, and the process fixes the energy status information E12V_PA to its nominal state, E12V_PA = "OK".

[0059] Function block B22 is used to detect the active status of the vehicle's voltage converter from the DCDC_ST voltage converter status information. Function block B22 activates a Y output when the information DCDC_ST = "OK" indicates that the converter is active. The activated output Y of the function block B22 is provided to a first input of a logic function B25 of type "OR" which validates the energy state information E12V_PA to its nominal state, E12V_PA = "OK".

[0060] When the voltage converter is inactive, DCDC_ST = "NOK", the function block B22 activates an output N which is supplied to a first input of a logic gate B26 of type "AND".

[0061] When the vehicle's voltage converter is inactive, DCDC_ST = "NOK", the STK12V electrical storage unit is the only available source of electrical energy for the accessory socket power supply functions. In this operating condition, to determine the nominal or degraded state to be assigned to the energy status information E12V_PA, the process integrates the permitted usage time DAmax_PA and the status information SOC_B, TEMP_B into its processing by means of function blocks B23 to B27.

[0062] Function block B23 compares the state of charge SOC_B of the STK12V electrical energy storage device to a state of charge threshold SOCmin_PA. The state of charge threshold SOCmin_PA is calibrated according to the temperature TEMP_B of the STK12V electrical energy storage device. Typically, a map (not shown), established beforehand using experimental data, is used to calibrate the state of charge threshold SOCmin_PA as a function of the temperature TEMP_B. Thus, for example, when the temperature TEMP_B is 20°C, the state of charge threshold SOCmin_PA could be equal to 65% of SOC_B, whereas when the temperature TEMP_B is -20°C, the state of charge threshold SOCmin_PA could be equal to 80% of SOC_B.

[0063] Function block B23 activates an output Y when the state of charge SOC_B is above the calibrated state of charge threshold SOCmin_PA. This active output Y of block 23 indicates to the process that the residual charge in the STK12V electrical storage unit has not reached a critical threshold for starting the vehicle and that the vehicle would be able to supply power via the accessory sockets PA. Conversely, if the state of charge SOC_B becomes equal to or below the calibrated state of charge threshold SOCmin_PA, function block B23 activates an output N, which indicates to the process that the charge in the STK12V electrical storage unit must be retained for a future vehicle start. The process then decides that the STK12V electrical storage unit is no longer able to supply power via the accessory sockets PA and stops using it.

[0064] Function block B24 checks the available allowed usage time DAmax_PA. As long as the DAmax_PA duration has not expired, DAmax_PA > 0, function block B24 activates a Y output which indicates to the process that the STK12V electrical storage device could still be used to power a electrical consumption via the PA accessory sockets. Otherwise, if the DAmax_PA time has elapsed, DAmax_PA = 0, the B24 function block activates an N output which indicates to the process that the STK12V electrical storage unit is no longer able to supply electrical consumption via the PA accessory sockets.

[0065] When the vehicle's voltage converter is inactive, DCDC_ST = "NOK", and the conditions SOC_B > SOCmin_PA and DAmax_PA > 0 are met, the N output of function block B22 applied to the first input of the AND logic gate B26, and the Y outputs of function blocks B23 and B24 applied to the second and third inputs of the AND logic gate B26, are all active. The AND logic gate B26 then validates the energy state information E12V_PA to its nominal state, E12V_PA = "OK", through a second input of the OR logic gate B25.

[0066] When at least one of the conditions SOC_B > SOCmin_PA and DAmax_PA > 0 is not satisfied, at least one of the outputs N of the functional blocks B23 and B24 applied to first and second inputs of the logic gate B27 of type "OR" is active and the logic gate B27 of type "OR" then validates the energy state information E12V_PA to its degraded state, E12V_PA = "NOK".

[0067] In general, the present invention allows better control of the energy management of the low voltage on-board electrical network in a vehicle and, in particular, in an electric vehicle, so as to avoid a starting failure due to an excessive discharge of the low voltage electrical storage.

[0068] The invention is not limited to the particular embodiment described herein by way of example. A person skilled in the art may, depending on the applications of the invention, make various modifications and variations falling within the scope of protection of the invention.

Claims

1. Demands Method for managing the energy consumption of an accessory power outlet (PA) in a vehicle, said accessory power outlet (PA) being connected to an on-board vehicle electrical system comprising a low-voltage electrical storage unit (STK12), said method comprising, when said vehicle is stationary, - a comparison (B23) between a state of charge (SOC_B) of said electrical storage (STK12V) and a calibrated state of charge threshold (SOCmin_PA), - a dynamic determination of a duration (DAmax_PA, DMAX) of authorized use of said electrical storage (STK12) to power a consumer device connected to said accessory power supply socket (PA), said authorized duration of use (DAmax_PA, DMAX) being determined according to at least one detected operating situation (DR_CY, DCDC_ST, CONS 12V) of said vehicle which affects an energy state of said low-voltage on-board electrical network, - a decision to authorize or not (E12V_PA, DM_eVCU) a power supply by said vehicle on-board electrical network of said consumer device connected to said accessory power supply socket (PA) which is taken according to the result of said comparison and said authorized usage time (DAmax_PA, DMAX), - a detection (B22), when said vehicle is stationary, of an activation of a voltage converter supplying power to said vehicle's on-board electrical network, and said decision to authorize or not (E12V_PA, DM_eVCU) a power supply by said vehicle's on-board electrical network to said consumer device connected to said accessory power supply socket (PA) being also taken according to the result of said detection, - a detection of a first said life situation which is an activation phase (DCDC_ST, B10) of said voltage converter for at least a first calibrated duration (B14, DminR12V) when said vehicle is stationary, - a detection of a second said life situation which is a vehicle started phase (DR_CY, B6) for at least a second calibrated duration (B13, DminR12V) before the said vehicle stopped, - a detection of a third said life situation which is an electrical consumption (B5, CONS 12) through said accessory power supply socket (PA) outside of said first and second life situations, and a periodic decrement (DEC) of said authorized use time (DAmax_PA) during said third detected life situation.

2. Method according to claim 1, characterized in that said state of charge threshold (SOCmin_PA) is calibrated as a function of a measured temperature (TEMP_B) of said electrical storage (STK12V).

3. Method according to claim 1, characterized in that it includes an initialization (INIT) of said authorized service time to a maximum value (DMAX) when said first life situation is detected and / or said second life situation is detected.

4. Calculator (ECU_12V) characterized in that it comprises a memory (MEM) storing program instructions (ESW) for the implementation of the method according to any one of claims 1 to 3.

5. Vehicle characterized in that it comprises a computer (ECU_12V) according to claim 4.

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