Energy management method for an auxiliary power outlet in a stationary motor vehicle

Abstract

The method is implemented in a vehicle in which the vehicle on-board electrical system comprises a low-voltage electrical store and an auxiliary outlet (PA) connected thereto. The method comprises, with the vehicle being stationary, dynamically determining an authorized usage duration (DAmax_PA) of the store for supplying power to a consumer connected to the auxiliary outlet, the authorized usage duration being determined on the basis of at least one detected life situation of the vehicle that affects an energy state of the electrical system, and a decision to authorize or not authorize (E12V_PA, DM_eVCU) a power supply from the electrical system to the consumer connected to the auxiliary outlet that is made on the basis of the authorized usage duration.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: METHOD FOR ENERGY MANAGEMENT OF AN ACCESSORY POWER SOCKET IN A STATIONARY MOTOR VEHICLE

[0003] The present invention claims priority from French application No. 2201893 filed on 04.03.2022, the content of which (text, drawings and claims) is incorporated herein by reference.

[0004] The invention generally relates 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 energy management of an accessory power outlet in a stationary motor vehicle. The invention is applicable in particular to an electric vehicle, but not exclusively.

[0005] Motor vehicles include in their passenger compartment one or more accessory power outlets connected to their low-voltage on-board electrical network, typically 12 V, into which it is possible to connect an accessory, such as a smartphone, for charging. The accessory power outlet, also referred to hereinafter as an "accessory outlet", is usually an ISO4166 type outlet, called a "cigarette lighter outlet", or a "USB" type (for "Universal Serial Bus" in English).

[0006] When the vehicle is stationary, with the on-board electrical network generator in an inactive state, the user is generally given the option of using the accessory socket, for example, to power their smartphone or another electrical consumer compatible with a 12 V power supply. In a conventional thermal vehicle, it is the 12 V electrical storage unit of the on-board electrical network which supplies electrical energy to the accessory connected to the socket and which, when the vehicle is stationary, will undergo a significant discharge in the event of prolonged use of this socket. In an electric vehicle, the same will apply if it is stationary and not connected to a terminal for recharging its high-voltage electrical storage unit.Otherwise, when the vehicle is connected to a charging station, the vehicle's DC-DC electric converter, as an electric generator for the on-board electrical network, will generally be active and will then provide electrical energy for the accessory connected to the socket and for additional charging of the 12 V electric storage device if necessary.

[0007] The 12 V electrical storage device of the on-board electrical network is a critical element of the vehicle, as it is generally the one that provides the electrical energy necessary for the vehicle's power-up and starting sequence, by powering all of its computers. It is therefore important to prevent excessive discharge of the 12 V electrical storage device by prolonged use of the accessory socket when the vehicle is stationary, even when information relating to the storage device, such as its state of charge, known as "SOC", for "State Of Charge" in English, its temperature or other information, is inaccessible. Indeed, failing to do so could result in a vehicle starting failure, due to the inability of the 12 V electrical storage device to provide the electrical energy necessary for the vehicle's starting sequence.

[0008] It is therefore desirable to propose a method for energy management of 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 when starting the vehicle.

[0009] The invention relates to a method for energy management of an accessory electrical power socket in a vehicle, the accessory electrical power socket being connected to an on-board vehicle electrical network comprising a low-voltage electrical storage device, the method comprising, when the vehicle is stationary, a dynamic determination of an authorized duration of use of the electrical storage device to power a consumer device connected to the accessory electrical power socket, the authorized duration of use being determined as a function of at least one detected life situation of the vehicle which affects an energy state of the low-voltage on-board electrical network, and a decision whether or not to authorize a power supply by the on-board vehicle electrical network of the consumer device connected to the accessory electrical power socket which is taken as a function of the authorized duration of use.

[0010] According to a particular characteristic, the method comprises, when the vehicle is stationary, a comparison between a state of charge of the electrical storage device and a calibrated state of charge threshold, and the decision to authorize or not a power supply by the vehicle's on-board electrical network of the consumer device connected to the accessory electrical power supply socket is also taken according to the result of the aforementioned comparison.

[0011] According to another particular characteristic, the state of charge threshold is calibrated according to a temperature of the electric storage device.

[0012] According to yet another particular characteristic, the method comprises 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 authorize or not a supply by the vehicle's on-board electrical network of the consumer device connected to the accessory electrical power socket is also taken as a function of the result of the aforementioned detection.

[0013] According to yet another particular characteristic, the method comprises a detection of a first life situation which is a phase of activation of the voltage converter for at least a first calibrated duration when the vehicle stops.

[0014] According to yet another particular characteristic, the method comprises a detection of a second life situation which is a phase of the vehicle started for at least a second calibrated duration before stopping the vehicle.

[0015] According to yet another particular characteristic, the method comprises a detection of a third life situation which is an electrical consumption through the accessory power supply socket outside the first and second life situations, and a periodic decrement of the authorized usage time during the detected third life situation.

[0016] According to yet another particular characteristic, the method comprises an initialization of the authorized duration of use to a maximum value when the first life situation is detected and / or the second life situation is detected.

[0017] The invention also relates to a computer which comprises 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.

[0018] Other advantages and characteristics of the present invention will appear more clearly on reading the detailed description below of a particular embodiment of the invention, with reference to the appended drawings, in which:

[0019] [Fig. 1] Fig. 1 is a block diagram showing different functions of a treatment process carried out for implementing the method according to the present invention.

[0020] [Fig.2] Fig.2 is a flowchart of a first function executed by the processing process implementing the method according to the present invention.

[0021] [Fig. 3 Fig. 3 is a flowchart of a second function executed by the processing process implementing the method according to the present invention.

[0022] [Fig .4] Fig .4 is a flowchart of a third function performed by the processing process implementing the method according to the present invention.

[0023] [Fig.5] Fig.5 is a flowchart of a fourth function performed by the processing process implementing the method according to the present invention.

[0024] 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.

[0025] With particular reference to Fig. 1, the method according to the invention is implemented in the vehicle by means of an embedded software module ESW. In this exemplary embodiment, the embedded software module ESW is installed in a supervisor computer ECU_12V of the on-board electrical network of the vehicle, more precisely in a memory MEM of this computer. For the implementation of the method of the invention, the supervisor computer ECU_12V is brought to cooperate, under the supervision of the software module ESW, with the main computer eVCU of the vehicle and possibly with other computers of the vehicle 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 supervisor computer ECU_12V, such as for example the aforementioned main computer eVCU or a computer (not shown) of a battery management system, called "BMS" for "Battery Management System" in English. The ESW software module authorizes the implementation of the method according to the invention by the execution of program code instructions by a processor (not shown) of the supervisor computer ECU_12V, in which the ESW module is hosted in this exemplary embodiment.

[0026] The ECU_12V supervisor calculator also hosts different strategies for supervising the vehicle's on-board electrical network, which are implemented by one or more SUP12V on-board software modules, hereinafter referred to as the "SUP12V supervisor module".

[0027] As shown schematically in Fig. 1, in this exemplary embodiment, 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.

[0028] In the vehicle, the power supply to the PA accessory sockets is established via a switch SW which is controlled in opening / closing by a C_PA command whose state is determined by the main eVCU computer. When the main eVCU computer 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 PA accessory sockets which are then able to fulfill their function of supplying power to the connected accessories. When the vehicle is stationary and a need for electrical power via a PA accessory socket is detected, if the necessary conditions are met, the process of the ESW software module wakes up the main eVCU computer to cause the power switch SW to close, by switching the C_PA command to the active state, and to supply electrical power to the PA accessory sockets.The waking up and / or keeping the eVCU main computer in the active state is controlled by the ESW software module process via a DM_eVCU request for activating the eVCU main computer which is established in accordance with the method of the invention. In this exemplary embodiment, the DM_eVCU main computer activation request is transmitted to the eVCU computer via the SUP12V supervisor module and the BCD data communication network.

[0029] As shown in Fig. 1, the SUP12V supervisor module receives status information SOC_B, TEMP_B, relating to the low-voltage electrical storage device STK12V from the vehicle's on-board electrical network and transmits this information to the ESW module to be used by its processing process detailed below. The SOC_B information is representative of an evaluated state of charge of the STK12V electrical storage device and the TEMP_B information is representative of the measured temperature of the STK12V electrical storage device. The SOC_B and TEMP_B information is transmitted to the SUP12V supervisor module typically by a BMS device (not shown) for battery management, via a data communication link, for example, of the "LIN" type for "Local Interconnect Network" in English.

[0030] In general, the processing process carried out by the software module SW and implementing the method of the invention notably carries out the actions briefly described below. Firstly, when the power supply functions via the PA accessory sockets of the vehicle are requested by the user, for example, to recharge his smartphone via a USB type PA socket of the vehicle, the process keeps the main computer eVCU of the vehicle active and informs the user of the fact that this eVCU computer is kept awake. Keeping the main computer eVCU active and the resulting power supply to the PA accessory sockets are managed by the process via the aforementioned DM_eVCU main computer activation request.To define the state of the DM_eVCU main computer activation request, the process dynamically calculates an authorized usage time of the electrical power supply functions via the PA accessory sockets, in order to control the discharge of the STK12V electrical storage device when the vehicle is stationary.

[0031] When calculating the permitted duration of use of the electrical power supply functions via the PA accessory sockets, the process takes into account the possibility of using the electrical energy supplied by the public electricity network via a charging station to which the vehicle is connected, so as to increase the availability for the user of these electrical power supply functions via the PA accessory sockets.

[0032] During a life phase where the vehicle is stationary, the process evaluates an energy state of the system ensuring the supply of low voltage electrical energy (12 V) to the vehicle, by integrating the possible energy supply through a charging station, to define the state of the activation request of the main computer DM_eVCU and to allow or not a discharge of the electrical storage STK12V for the electrical supply functions via the accessory sockets PA.

[0033] As visible in Fig. 1, the processing process of the ESW software module essentially comprises four functions F1 to F4 for implementing the method according to the invention. The functions F1 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.

[0034] With reference to Figs. 1 and 2, the function F1 is responsible for establishing the activation request for the main computer DM_eVCU according to the vehicle's life situation. The function F1 receives as input information BA_PA representing a power supply requirement on an accessory socket PA and information E12V_PA representing the energy state of the system ensuring the supply of low voltage electrical energy (12 V). The function F1 delivers as output the activation request for the main computer DM_eVCU. The power supply requirement information BA_PA is typically provided by the supervisor module SUP12V hosted by the supervisor computer ECU-12V which manages the on-board electrical network, but it may also come from a vehicle computer other than the supervisor computer ECU_12V through the BCD data communication network.The power supply requirement information BA_PA is active, BA_PA = "OK", when a power supply requirement has been detected following the connection by the user of an electrical consumer to a PA accessory socket and is inactive, BA_PA = "NOK", otherwise. The energy status information E12V_PA is active, E12V_PA = "OK", when the low voltage electrical energy supply system is in a nominal state and is inactive, E12V_PA = "NOK", when the low voltage electrical energy supply system is in a degraded state. When the energy status information E12V_PA is in the active state, E12V_PA = "OK", the discharge of the STK12V electrical storage device can be authorized by the process for a power supply of an electrical consumer through the PA accessory sockets. The energy status information E12V_PA is produced by the function F4 which will be described below with particular reference to the flowchart in Fig.5.

[0035] As visible in the flowchart of Fig. 2, functional blocks B1 to B4 cooperate to establish the activation request of the main computer DM_eVCU according to the information BA_PA and E12V_PA. Function 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". Function block B2 activates an output Y when the energy state information E12V_PA indicates a nominal energy state, E12V_PA = "OK", and activates an output N otherwise, when the energy state information E12V_PA indicates a degraded energy state, E12V_PA = "NOK". The logic function B3 of type “AND” delivers the request to activate the main computer DM_eVCU in the active state, DM_eVCU = “OK”, when the two outputs “Y” of the functional blocks B1 and B2 are active.The logic function B4 of type “OR” delivers the request to activate the main computer DM_eVCU in the inactive state, DM_eVCU = “NOK”, when at least one of the two outputs “N” of the functional blocks B1 and B2 is active.

[0036] With reference to Figs. 1 and 3, the function F2 is responsible in the process of confirming an electrical consumption on an accessory socket PA, which is likely to cause a discharge of the electrical storage device STK12V. For this, the function F2 outputs an electrical consumption information CONS12V which is in the active state, CONS12V = "OK", when an electrical consumption is effective and in the inactive state, CONS12V = "NOK", otherwise. The electrical consumption information CONS12V is established from the main computer activation request DM_eVCU which informs in the active state, DM_eVCU = "OK", that the main computer eVCU is kept awake and therefore that an electrical energy consumption is in progress on an accessory socket PA.

[0037] As visible in Fig.1, the CONS12V power consumption information is provided as input to the F3 function described later in the description.

[0038] As visible in the flowchart of Fig. 3, a functional block B5 receives as input the request for activation of the main computer DM_eVCU and delivers as output the power consumption information CONS12V. The functional block B5 activates an output Y which validates the power consumption information CONS12V = “OK” when the request for activation of the main computer DM_eVCU is active, DM_eVCU = “OK”. The functional block B5 activates an output N which validates the power consumption information CONS12V = “NOK” when the request for activation of the main computer DM_eVCU is inactive, DM_eVCU = “NOK”.

[0039] With particular reference now to Figs. 1 and 4, the function F3 is responsible for dynamically assigning and updating an authorized usage time DAmax_PA of the STK12V electrical storage device to supply, when the vehicle is stationary, a consumer device connected to a PA accessory socket. The function F3 makes it possible in particular to energetically secure the STK12V electrical storage device against excessive discharges, even when it is not possible to know the charge state of the storage device. Indeed, as will become clear from the description below of the function F4, once the authorized usage time DAmax_PA has elapsed, the energy status information E12V_PA switches to its degraded state, E12V_PA = "NOK", thus prohibiting the waking up of the main computer eVC11 and therefore the use of the PA accessory sockets.

[0040] The function F3 receives as input a voltage converter status information DCDC_ST which indicates the active or inactive state of the vehicle voltage converter, a vehicle start / stop information DR_CY which indicates whether or not the vehicle is in a started vehicle phase and the aforementioned electrical consumption information CONS12V and provides as output the authorized usage time DAmax_PA. The voltage converter status information DCDC_ST and the vehicle start / stop information DR_CY are typically provided by the supervisor module SUP12V or can come from a vehicle ECU other than the supervisor ECU ECÙ_12V, through the BCD data communication network.

[0041] As visible in the flowchart of Fig.4, the function F3 essentially comprises three sub-functions BK0, BK1 and BK2.

[0042] The BK0 subfunction is a counter that provides the current value of the authorized usage time DAmax_PA.

[0043] The BK0 counter can be initialized to a maximum duration value DMAX (DAmax_PA = DMAX), for example equal to 30 minutes (mn). The BK1 subfunction is responsible for managing the initialization of the duration DAmax_PA = DMAX in the BK0 counter.

[0044] With the vehicle stationary, when the power supply to a consumer via an accessory socket PA is provided by the STK12V electrical storage device, the DAmax_PA duration in the BK0 counter is decremented periodically, until it eventually reaches a zero value, DAmax_PA = "0", which will end the use of the STK12V electrical storage device for this power supply. Thus, for example, the DAmax_PA duration can be decremented by one (1), DAmax_PA = DAmax_PA - 1, every DD seconds, with DD = 1 s. This decrement of the DAmax_PA duration in the BK0 counter is managed by the BK2 subfunction.

[0045] Subfunctions BK1 and BK2 are now described above.

[0046] As visible 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 at the duration DAmax_PA = DMAX.

[0047] The BK10 function module essentially comprises the function blocks B6 to B12. This BK10 function module detects life situations in which the STK12V electrical storage device has potentially been charged following a vehicle-start phase or has been charged following activation of the vehicle's voltage converter. The function blocks B6 to B8 detect the life situation in which the vehicle changes from a vehicle-start phase to a vehicle-stop phase and the vehicle's voltage converter is inactive due to the vehicle not being connected to a charging station. The 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 an output Y when the transition from DR_CY = "OK" to DR_CY = "NOK" is detected and, otherwise, activates an output N for a waiting loop. Function block B7 processes the voltage converter state information DCDC_ST to detect inactivity, DCDC_ST = "NOK", of the voltage converter. Function block B7 activates an output Y when the condition DCDC_ST = "NOK" is satisfied and, otherwise, activates an output N for a waiting loop. The outputs Y of function blocks B6 and B7 are provided as input to logic gate B8 of type "AND". When the two outputs Y of function blocks B6 and B7 are active, logic gate B8 of type "AND" delivers, through logic gate B12 of type "OR", a first condition validation output DC1 in an active state which is applied to a first input of logic gate B16 of type "AND".

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

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

[0050] The BK11 functional module is used to confirm sufficient charging time of the STK12V electric storage device following a vehicle start phase or a phase of activation of the vehicle's voltage converter by connection to a charging station.

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

[0052] Function block B13 detects the first aforementioned life situation. Function block B13 processes the vehicle start / stop information DR CY to detect a started vehicle phase, DR CY = "OK", having at least a calibrated duration DminR12V equal to, for example, 5 min. 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 waiting loop. Function block B14 detects the second aforementioned life situation. 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 waiting 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 in the active state 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 a counter initialization command INIT in the active state which sets the authorized usage duration DAmax_PA to DMAX, DAmax_PA = DMAX.

[0054] As can be seen in Fig. 4, the sub-function BK2 essentially comprises four functional blocks B18 to B21 which cooperate to establish a counter decrement command DEC. The command DEC is supplied to the counter BK0 for the decrement of the authorized usage time DAmax_PA. In the management carried out by the sub-function BK2, the authorized usage time DAmax_P is decremented when an electrical consumption is effective while the vehicle voltage converter is not active and the vehicle is stopped, in other words, when the electrical supply via an accessory socket PA, vehicle stopped, is provided by the electrical storage device STK12V.

[0055] Function block B18 processes the vehicle start / stop information DR_CY to detect a stop phase, DR_CY = "NOK", of the vehicle. Function block B18 activates an output Y when the condition DR_CY = "NOK" is satisfied and, otherwise, activates an output N for a waiting loop. Function block B19 processes the voltage converter status information DCDC_ST to detect an inactivity phase, DCDC_ST = "NOK", of the vehicle voltage converter. Function block B19 activates an output Y when the condition DCDC_ST = "NOK" is satisfied and, otherwise, activates an output N for a waiting loop. Function block B20 processes the power consumption information CONS12V to detect power consumption via an accessory socket PA. Function block B20 activates an output Y when the condition CONS12V = "OK" is satisfied and, otherwise, activates an output N for a waiting loop.The Y outputs of function blocks B18, B19 and B20 are provided as input to the “AND” logic gate B21. When the three Y outputs of function blocks B18, B19 and B20 are active, the “AND” logic gate B21 delivers a counter decrement command DEC in the active state which causes a reduction by decrement of the authorized usage time DAmax_PA in the counter BK0.

[0056] Referring now more particularly to Figs. 1 and 5, the function F4 is responsible for establishing and delivering the aforementioned energy status information E12V_PA, for exploitation thereof by the function F1. To establish the energy status information E12V_PA, the function F4 exploits the aforementioned voltage converter status information DCDC_ST, as well as status information of the electrical storage device STK12V, namely, the aforementioned state of charge information SOC_B and temperature information TEMP_B, and the authorized usage time DAmax_PA determined by the function F3.

[0057] As visible in the flowchart of Fig.5, functional blocks B22 to B27 cooperate to produce the energy status 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 energy to the on-board electrical network. In this life situation, the risk of discharging the 12V storage device by using the PA accessory sockets is limited and the process sets the energy status information E12V_PA to its nominal state, E12V_PA = "OK".

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

[0060] When the voltage converter is inactive, DCDC_ST = “NOK”, the functional 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 voltage converter is inactive, DCDC_ST = "NOK", the STK12V electrical storage device is then the only source of electrical energy available for the PA accessory socket power supply functions. In this life situation, to determine the state, nominal or degraded, to be assigned to the E12V_PA energy status information, the process integrates into its processing the authorized usage time DAmax_PA and the status information SOC_B, TEMP_B, by means of the functional blocks B23 to B27.

[0062] Function block B23 compares the state of charge SOC_B of the STK12V electrical 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 storage device. Typically, a map (not shown), previously established using experimental data, is used to calibrate the state of charge threshold SOCmin_PA according to 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 higher than 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 device has not reached a critical threshold for starting the vehicle and that the vehicle would be able to supply electrical consumption via the PA accessory sockets. In the opposite case where the state of charge SOC_B becomes equal to or lower than the calibrated state of charge threshold SOCmin_PA, function block B23 activates an output N which indicates to the process that the charge present in the STK12V electrical storage device must be kept for a future start of the vehicle. The process then decides that the STK12V electrical storage device is no longer able to supply electrical consumption via the PA accessory sockets and stops using it.

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

[0065] When the vehicle voltage converter is inactive, DCDC_ST = "NOK", and the conditions SOC_B > SOCmin_PA and DAmax_PA > 0 are satisfied, the N output of the functional block B22 applied to the first input of the "AND" type logic gate B26 and the Y outputs of the functional blocks B23 and B24 applied to the second and third inputs of the "AND" type logic gate B26 are all three active. The "AND" type logic gate B26 then validates the energy status information E12V_PA to its nominal state, E12V_PA = "OK", through a second input of the "OR" type 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 the “OR” type is active and the logic gate B27 of the “OR” type then validates the energy state information E12V_PA in 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 excessive discharge of the low-voltage electrical storage device.

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

Claims

DEMANDS 1. A method for managing the energy of an accessory power outlet (PA) in a vehicle, said accessory power outlet (PA) being connected to a vehicle's on-board electrical system comprising a low-voltage electrical energy storage unit (STK12), said method comprising, when said vehicle is stationary, a comparison (B23) between a state of charge (SOC_B) of said electrical energy storage unit (STK12V) and a calibrated state of charge threshold (SOCmin_PA), a dynamic determination of a duration (DAmax_PA, DMAX) of permissible use of said electrical energy storage unit (STK12) to power a consumer device connected to said accessory power outlet (PA), said duration of permissible use (DAmax_PA, DMAX) being determined based on at least one detected operating condition (DR CY, DCDC_ST, CONS12V) of said vehicle that affects an energy state of said low-voltage on-board electrical system, and a decision to permit or not (E12V_PA,DM_eVCU) a power supply via said vehicle's 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).

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 or 2, characterized in that it comprises a detection (B22), when said vehicle is stationary, of an activation of a voltage converter supplying energy to said vehicle on-board electrical network, and in that said decision to authorize or not (E12V_PA, DM_eVCU) a supply by said vehicle on-board electrical network of said consumer device connected to said accessory power supply socket (PA) is also taken according to the result of said detection.

4. Method according to claim 1 or 2 and claim 3, characterized in that it comprises 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 stopped.

5. Method according to any one of claims 1 to 4, characterized in that it comprises 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, DminRI 2V) before the stopping of said vehicle.

6. Method according to claims 4 and 5, characterized in that it comprises a detection of a third said life situation which is an electrical consumption (B5, CONS12) through said accessory power supply socket (PA) outside of said first and second life situations, and a periodic decrement (DEC) of said authorized usage time (DAmax_PA) during said detected third life situation.

7. Method according to claims 4 and 5 or claim 6, characterized in that it comprises an initialization (IN IT) 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. Computer (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 7. Vehicle characterized in that it comprises a computer (ECU_12V) according to claim 8.

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