System and method for managing the electrical powering of at least one piece of equipment during the automatic restarting of an internal combustion engine of a vehicle

Abstract

A system and method for management of electrical powering of at least one piece of electrical equipment by a power supply battery of a motor vehicle including an internal combustion engine. The motor vehicle includes a system for automatically stopping and restarting the internal combustion engine. The system and method: determine a charge status of the power supply battery; compare the charge status of the power supply battery with a predefined threshold value; and control cutting off of the power supply to the at least one piece of electrical equipment during an automatic restarting of the internal combustion engine if the charge status of the power supply battery is lower than the predefined threshold value.

Claims

1. A system for managing an electrical power supply of at least one item of electrical equipment by an electrical power supply battery of a combustion-engine motor vehicle, the motor vehicle including a system for automatically stopping and restarting the combustion engine, the management system comprising: an electrical load-shedding supervision module configured to compare a state of charge of the power supply battery with a predefined threshold value and to command, during an automatic stopping condition of the motor vehicle whereby the combustion engine has been automatically stopped, cutting-off of the electrical power supply for the at least one item of electrical equipment immediately prior to and during an automatic restarting of the combustion engine responsive to the comparing the state of charge of the power supply battery with the predetermined threshold value indicating that the state of charge of the electrical power supply battery is less than the predefined threshold value.

2. The management system as claimed in claim 1, wherein the electrical load-shedding supervision module is configured to determine the state of charge of the power supply battery from environmental parameters and from measurements of a battery voltage and current.

3. The management system as claimed in claim 1, further comprising one or more links to directly connect the electrical load-shedding supervision module to the at least one item of electrical equipment to cut off its electrical power supply.

4. The management system as claimed in claim 3, wherein the electrical load-shedding supervision module is connected by a link to load-shed, via an inter-system load-shedding request indication, the at least, one item of electrical equipment.

5. The management system as claimed in claim 1, further comprising a module connected to the electrical load-shedding supervision module by a link to load-shed, via an inter-system load-shedding request indication, the electrical power supplies of the at least one item of electrical equipment.

6. A method for managing an electrical power supply of at least one item of electrical equipment by an electrical power supply battery of a combustion-engine motor vehicle, the motor vehicle including a system for automatically stopping and restarting the combustion engine, the method comprising: determining a state of charge of the electrical power supply battery; during an automatic stopping condition of the motor vehicle whereby the combustion engine has been automatically stopped, comparing the state of charge of the power supply battery with a predefined threshold value; and cutting off the electrical power supply of the at least one item of electrical equipment immediately prior to and during an automatic restarting of the combustion engine responsive to said comparing indicating that the state of charge of the electrical power supply battery is less than the predefined threshold value.

7. The method as claimed in claim 6, wherein said comparing is preceded by detecting reception of an instruction signal indicating that a restarting of the combustion engine is required.

8. The method as claimed in claim 7, wherein the instruction signal is sent by an automatic restarting management module of the system for automatically stopping and restarting the combustion engine.

9. The method as claimed in claim 6, wherein said comparing precedes an order for restarting the combustion engine.

10. The method as claimed in claim 9, wherein said cutting off is followed by validating a restarting order.

Description

(1) The invention and the various advantages which it provides will be better understood in view of the following description, given with reference to the appended figures, in which:

(2) FIG. 1, already described, schematically illustrates a known system for managing the power supply of electrical equipment during a restarting of the combustion engine of a motor vehicle;

(3) FIG. 2, already described, represents the steps of the management method generally implemented with the system of FIG. 1;

(4) FIG. 3 schematically illustrates a system for managing the power supply of electrical equipment during a restarting in accordance with a first embodiment of the invention;

(5) FIG. 4 describes the steps that can be implemented by the system of FIG. 3, according to a first management method in accordance with the invention;

(6) FIG. 5 describes the steps that can be implemented by the system of FIG. 3, according to a second management method in accordance with the invention;

(7) FIG. 6 schematically illustrates a system for managing the power supply of electrical equipment during a restarting in accordance with a second embodiment of the invention;

(8) FIG. 7 is a variant of the management system of FIG. 6.

(9) In the whole of the description, items common to the various figures bear the same references.

(10) In FIG. 3, there is presented a configuration of a system equipping a motor vehicle, similar to that already described with reference to FIG. 1, with a system 1 for managing the electrical power supply of a plurality of items of comfort equipment 3.sub.1, 3.sub.2, . . . , 3.sub.N via the vehicle battery (not represented) and a module 2 managing the restarting of the combustion engine (not represented) of the vehicle. Unlike in FIG. 1 however, the management system according to the invention includes here a load-shedding supervision module 5 connected, on the one hand, to the automatic restarting module. 2, and, on the other hand, to the system 1 for managing the electrical power supply of the equipment 3.sub.1, 3.sub.2, . . . , 3.sub.N. The connections used between the various modules and the equipment are conventional wire links 4 or local network links (CAN, LIN, MOST, etc.) and electrical power supply links 6.

(11) The load-shedding supervision module 5 is able to assess, from environmental parameters P.sub.ENV such as temperature and ageing and from voltage and current measurements M.sub.BAT carried out on the battery, the state of charge SOC of the battery. As a variant, the module 5 could receive a determination of the state of charge SOC by another item of equipment, for example a battery management module. In all cases, the load-shedding supervision module 5 will use this state of charge to decide whether it is appropriate to cut off the electrical power supply to one or more of said items of comfort equipment 3.sub.1, 3.sub.2, . . . , 3.sub.N when an automatic stopping of the combustion engine has been performed, and whether it is appropriate to restart this engine.

(12) An example of operation of the system according to the invention is explained with reference to FIG. 4. In this figure, there is presented the initial step S.sub.0 corresponding to the vehicle in the “stopped engine” situation, all the electrical comfort equipment 3.sub.1, 3.sub.2, . . . , 3.sub.N nevertheless still being powered by the vehicle battery. During step S.sub.3, the load-shedding supervision module 5 determines the state of charge SOC of the battery from environmental parameters P.sub.ENV and from battery measurements M.sub.BAT which it receives. The module 5 additionally verifies, at step S.sub.1, whether it receives from the automatic restarting management module 2 an instruction signal S.sub.C indicating that a restarting of the combustion engine is required. From the moment this instruction signal S.sub.C is received, the module 5 then compares the state of charge SOC determined at step S.sub.3 with a predefined threshold value V.sub.T (step S.sub.4). The threshold value V.sub.T is adjusted beforehand, for example at the factory, according to the electrical comfort equipment equipping the motor vehicle, or according to a subset of such comfort equipment, in such a way as to indicate the minimum state of charge that the battery must have in order to provide for an automatic restarting while leaving the electrical comfort equipment powered. Thus, in use, the cutting-off of the electrical power supply to the comfort equipment (or to the electronic computers driving this electrical equipment) is commanded by the load-shedding supervision module 5 only if the state of charge SOC is less than the threshold value V.sub.T (step S.sub.5). In the other cases, the restarting is performed while keeping the comfort equipment powered.

(13) In some cases, depending on the motor vehicles, the automatic restarting management module 2, the load-shedding supervision module 5 and the electrical management system 1 can be quite far apart from one another. The result of this is that the data exchange times via the links 4 can be quite significant, with the risk that the cutoff order is not received early enough. FIG. 5 illustrates another way of using the management system according to the invention, enabling this problem to be overcome. In this case, the load-shedding supervision module 5 does not wait to receive an instruction signal indicating that a restarting order is required. In a different way, it determines the state of charge (step S.sub.3) and compares this state of charge (step S.sub.4) with the threshold value V.sub.T, then orders the cutoff of at least one item of electrical equipment (step S.sub.5 if the state of charge is less than the threshold value V.sub.T. The supervision module 5 then sends to the automatic restarting management module 2 a validation signal indicating that a restarting can be performed (step S.sub.6). By thus anticipating the restarting instruction, it is ensured that all the conditions are met for enabling an automatic restarting of the engine, even if the state of charge of the battery is not high enough to also allow the comfort equipment to be supported.

(14) In the case of the architecture of FIG. 3, the cutoff orders are sent by the load-shedding supervision module 5 to the electrical power supply management system 1. Other architectures can nevertheless be envisaged, without departing from the scope of the present invention. Thus, as illustrated in FIG. 6, the load-shedding supervision module 5 is directly connected to the various items of electrical comfort equipment 3.sub.N+1, 3.sub.N+2, . . . , 3.sub.N+M. FIG. 7 illustrates, for its part, another variant in which the load-shedding supervision module 5 is connected: on the one hand, to N items of electrical comfort equipment 3.sub.1, 3.sub.2, . . . , 3.sub.N via an electrical power supply management system 1 for this equipment, and on the other hand, directly to M other items of electrical comfort equipment 3.sub.N+1 to 3.sub.N+M.

(15) It is moreover noted that, in the invention, it is not necessary to be concerned with knowing whether or not the items of electrical comfort equipment have been activated by the vehicle occupants before an automatic restarting order.