EP2191127A2

EP2191127A2 - Method and device for controlling an engine stop/restart system to be mounted on an automobile

Info

Publication number: EP2191127A2
Application number: EP08827922A
Authority: EP
Inventors: Daniel Benchetrite; Benoît SOUCAZE-GUILLOUS; Ertugrul Taspinar; Magali Laurence; Paul Eric Chupin; Frédéric DEVANNE; Brice Lecole; Benoît GAREIL
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2007-08-23
Filing date: 2008-07-28
Publication date: 2010-06-02
Also published as: WO2009024706A3; BRPI0814499A2; CN101784789A; CN101784789B; WO2009024706A2; FR2920192B1; FR2920192A1; US20110232597A1

Abstract

The invention relates to a method and a device (5) for controlling an engine stop/restart system (1) to be mounted on an automobile, wherein said device (5) includes a control module (6) including means for obtaining at least one parameter (Tbat, Ubat, Ibat) representative of the state of an energy storage unit (8), means for determining an information on the energetic state of the energy storage unit (8) from said at least one obtained parameter (Tbat, Ubat, Ibat), and means for controlling the engine stop/restart system (1) based on the determined energetic state information. The energetic state information is set at a predetermined value when the method controls a stop authorisation of the engine stop/restart system (1).

Description

Method and device for controlling an engine stop / restart system suitable for equipping a motor vehicle

The present invention relates to a method and a device for controlling a motor stop / restart system fitted to a motor vehicle. In the engine stop / restart systems, there may be problems of availability of the stop and restart functions of the engine, these functions being impacted by the state of the battery.

In a vehicle having an engine stop / restart system, it would be desirable to have a system for managing the electrical power in the vehicle.

In a conventional system for managing electrical power in a vehicle, a battery and a rotating electrical machine power electrical consumers.

The rotating electrical machine, capable of operating as an alternator, is also intended to recharge the battery via a regulating device.

Typically, when the vehicle's engine is running, the alternator powers the electrical consumers and charges the battery. When the alternator does not deliver power, the battery provides all the electrical energy that the vehicle needs. With the increase in the number of on-vehicle electrical consumers, it is necessary to perform an intelligent management of the state of the battery in particular to always start the engine. The implementation of this vehicle management requires knowing the energy status of the battery.

It is not easy to know exactly the energy state of the battery. Factors affecting the performance of the battery are for example the state of charge ("SOC"), the capacity, the level of concentration of the electrolyte, the charging conditions, the temperature , the internal resistance. In addition, some parameters depend on the conditions of use.

Patent FR 2853081 discloses a device for determining an instantaneous state of charge (SOC) of an energy storage battery for a motor vehicle, applied in a battery manager and able to control corrective actions. The device is designed to control the shutdown of electrical functions such as a car radio, an air conditioning device or a parking assistance device. The device comprises a calculation circuit of an extended Kalman filter receiving input information concerning an initial state of charge of the battery, a voltage measured across the battery and a temperature thereof. This information makes it possible, thanks to the extended Kalman filter, to determine the instantaneous state of charge of the battery during the operation of the vehicle. The determination device described in patent FR 2853081 is not suitable for a motor stop / restart system. In addition, this device results in a complex implementation of an extended Kalman filter. In addition, this type of device according to the patent FR 2853081 is applicable only for a given battery, hence the need to modify the determination device, and more particularly the Kalman filter, for each battery model. There is therefore a need to know the battery power state reliably, simply, and standard at least for a battery technology, to allow to manage the use of the battery under intelligent and optimal conditions, and also to strengthen the performance of engine stop / restart systems, particularly in terms of respect for the environment. The invention aims to meet the aforementioned needs.

According to a first aspect, the invention relates to a control method of an engine stop / recovery system fitted to a motor vehicle. The control method comprises steps of:

to obtain at least one parameter representative of a state of an energy storage unit,

determining energy state information of the energy storage unit from said at least one parameter obtained, and

- control the engine stop / restart system according to the determined energy status information. According to the invention, the energy state information is initialized to a predetermined value when the method controls an authorization to stop the engine stop / restart system. The command to authorize the stopping of the engine stop / restart system is characteristic of a sufficient energy state of the energy storage unit.

The initialization of said energy state at this instant makes it possible to define a reference energy state from which the management of the battery is carried out.

Starting from this reference energy state, the battery can thus be managed simply and reliably by defining in particular fixed thresholds of energy states, these thresholds being associated in particular with controls of the engine stop / restart system.

Thanks to the invention, the engine stop / restart system is used optimally depending on the energy state of the energy storage unit. Thus, the risks, for example of non-recovery of the engine after a stop, are eliminated. The operational safety of the vehicle is thus improved. In addition, the implementation of the method is simple and standard to a set of different energy storage units.

According to different embodiments of the method, the parameter comprises at least one of the following parameters:

a temperature representative of a thermal state of the energy storage unit,

a voltage representative of an electrical state of the energy storage unit,

a current representative of an electrical state of the storage unit energy.

According to a particular embodiment of the method, the step of determining the energy state information comprises sub-steps of:

determining a state of charge as a function of the voltage and temperature of the energy storage unit, and

comparing the determined state of charge with a predetermined state of charge threshold value.

The state of charge can be determined according to a type of energy storage unit. By type is meant a set of energy storage units having similar technologies, eg lead acid battery, and different characteristics. These characteristics can be for example the voltage, the current, the capacity of the energy storage unit.

According to another particular embodiment of the method, the step of determining the energy state information comprises sub-steps of: determining a current threshold value as a function of the temperature of the storage unit of energy, and

comparing the current of the energy storage unit with the determined current threshold value.

determining an energy balance according to the current of the energy storage unit, and

- compare the energy balance determined with a threshold value of predetermined energy balance.

According to yet another particular embodiment of the method, the step of determining the energy state information comprises a substep of comparing the voltage of the energy storage unit with a predetermined voltage threshold value.

According to a first embodiment of the invention, the step of controlling the engine stop / restart system comprises a substep of authorizing a stopping of the engine.

According to a characteristic of this first embodiment of the invention, the sub-step of authorizing an engine stop is performed when the state of charge of the energy storage unit is greater than or equal to the value of predetermined state of charge threshold.

According to another characteristic of this first embodiment of the invention, the sub-step of authorizing a stopping of the motor is carried out when the current of the energy storage unit is less than or equal to the threshold value of determined current. This characteristic is advantageous in the case where the energy storage unit is in a so-called charge state.

According to a particular characteristic of this first embodiment of the invention, the sub-step of authorizing an engine stop is performed when the energy balance of the energy storage unit is greater than or equal to the threshold value. predetermined energy balance.

In this case, the energy balance is initialized to a predetermined value, for example zero. According to yet another characteristic of this first embodiment of the invention, the sub-step of authorizing an engine stop is performed when:

the energy balance of the energy storage unit is greater than or equal to the predetermined energy balance threshold value, and the energy storage unit current is less than or equal to the threshold value of the energy storage unit. determined current.

If necessary, the energy balance is initialized to a predetermined value, for example zero.

This characteristic is interesting in the case where the energy storage unit is in a state called charge.

According to a second embodiment of the invention, the step of controlling the engine stop / restart system comprises a substep of prohibiting a stopping of the engine.

According to one characteristic of this second embodiment of the invention, the sub-step of prohibiting an engine stop is performed when the energy balance of the energy storage unit is less than or equal to the threshold value of predetermined energy balance.

According to a particular characteristic of this second embodiment of the invention, the sub-step of prohibiting the motor stop can be performed when the voltage of the energy storage unit is less than or equal to a threshold value. predetermined voltage. This feature is interesting in the case where the energy storage unit is in a state of no load.

According to a third embodiment of the invention, the step of controlling the engine stop / restart system has a substep of requesting a restart of the engine. In the case where the energy storage unit is not charging, this third embodiment makes it possible to ensure the restart of the vehicle following a stop having caused a degradation of the energy state of the vehicle. energy storage unit.

According to a characteristic of this third embodiment of the invention, the sub-step of requesting a restart of the motor is performed when the voltage of the energy storage unit is less than or equal to a predetermined voltage threshold value. . According to another characteristic of this third embodiment of the invention, the substep of requesting a restart of the motor is performed when the energy balance of the energy storage unit is less than or equal to the threshold value of predetermined energy balance.

According to a fourth embodiment of the invention, the step of controlling the engine stop / restart system comprises a substep of canceling a request to restart the engine.

According to a feature of this fourth embodiment of the invention, the substep of canceling a request to restart the engine is performed when the energy balance of the energy storage unit is greater than or equal to the value of predetermined energy balance threshold.

According to another characteristic of this fourth embodiment of the invention, the substep of canceling an engine restart request is made when the current of the energy storage unit is less than or equal to the current threshold value determined.

According to one particular characteristic of the invention, the step of determining the energy state information of the energy storage unit is preceded by a step of comparing the temperature of the energy storage unit with a predetermined temperature threshold value.

The step of determining the energy status information of the energy storage unit can be performed when the temperature of the energy storage unit is greater than or equal to the predetermined temperature threshold value.

In addition, when the temperature of the energy storage unit is lower than the predetermined temperature threshold value, the control module can control the engine stop / restart system so as to prohibit stopping the engine.

According to a particular characteristic of the invention, the step of determining the energy state information of the energy storage unit is preceded by steps of:

determining a reference voltage as a function of the temperature of the energy storage unit, and

comparing the voltage of the energy storage unit with the determined reference voltage. The step of determining the energy status information of the energy storage unit can be performed when the voltage of the energy storage unit is substantially equal to the determined reference voltage.

In addition, when the voltage of the energy storage unit is not substantially equal to the determined reference voltage, the control module can control the engine stop / restart system so as to prohibit stopping the engine.

According to a second aspect, the invention relates to a device for controlling an engine stop / restart system adapted to equip a motor vehicle, comprising a control module, said control module comprising:

means for obtaining at least one parameter representative of a state of an energy storage unit,

means for determining energy state information of the energy storage unit from said at least one parameter obtained, and

means for controlling the engine stop / restart system according to the determined energy state information.

According to one characteristic of the invention, the control module is located at least partially in a control unit and intended to control the engine stop / restart system.

According to another characteristic of the invention, the means for obtaining at least one parameter representative of a state of a energy storage unit comprises sensors designed to obtain at least one of the following parameters: a temperature of the energy storage unit,

a voltage of the energy storage unit,

a current of the energy storage unit.

The sensors can be placed on the energy storage unit. If desired, the control module can be placed in the sensors. According to a third aspect, the invention relates to an engine stop / restart system comprising a rotating electrical machine, a reversible digital analog converter and control means of the control device. The rotating electric machine can be an altemo-starter.

According to a last aspect, the invention relates to a motor vehicle comprising a motor stop / restart system.

Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the figures which it comprises, among which:

FIG. 1 shows an overall view of a motor stop / restart system 1 comprising a control module 6 of a control device 5 according to the invention,

FIG. 2 relates to a first stop authorization authorization processing sub-module, of the control module 6 of FIG. 1, activated during a parking phase and during a first start phase, according to a particular embodiment of the method. ,

FIG. 3 relates to a first stop authorization authorization processing sub-module, of the control module 6 of FIG. 1, activated during a first start phase, according to another particular embodiment of the method,

FIG. 4 relates to a motor stop inhibit processing sub-module, of the control module 6 of FIG. 1, activated during a phase of normal operation, according to a particular embodiment of the method,

FIGS. 5 and 6 relate to an engine stop authorization processing sub-module, of the control module 6 of FIG. 1, activated during a normal operating phase, according to two particular embodiments of the method,

FIGS. 7 and 8 relate to a motor restart request processing sub-module, of the control module 6 of FIG. 1, activated during a normal operating phase, according to two particular embodiments of the method, and FIGS. and 10 relate to a cancellation processing sub-module request motor restart, the control module 6 of Figure 1, activated during a normal operating phase, according to two particular embodiments of the method.

FIG. 1 shows an engine stop / restart system 1 comprising a multi-phase reversible rotary electric machine 2, a reversible digital analog converter 3, a control unit 4, and a control device 5.

The reversible rotary polyphase electrical machine 2 is formed, in this example, by a motor vehicle starter. The alternator-starter 2 is capable, in addition to being rotated by a heat engine 9 to produce electrical energy (alternator mode), to transmit a torque to the engine 9 for a start (starter mode). Alternatively, the alternator-starter can be used in a regenerative braking type architecture, in order to convert a portion of the mechanical energy from braking into electrical energy.

In another variant, the engine stop / restart system may comprise a conventional alternator associated with a starting device, instead of the altemo-starter.

Altemo-starter 2, converter 3 and an energy storage unit 8 are connected in series.

The energy storage unit 8 may comprise a conventional battery pack, for example of the lead-acid battery type. This battery 8 makes it possible, in addition to supplying the alternator-starter during a starting phase (motor mode), to supply electrical energy to electrical consumers of the vehicle, for example headlamps, a car radio, an air conditioning device. wipers. The converter 3 allows bidirectional transfers of electrical energy between the alternator-starter 2 and the battery 8, these transfers being in particular controlled by the control unit 4 connected to the converter.

The control unit 4 of the engine stop / restart system 1 can be built around a microprocessor. In the starter mode (or motor mode), the microprocessor 4 controls the converter 3 to take a DC voltage from the battery 8 to supply the starter-starter 2. In the alternator mode (or generator mode), in normal operation or in regenerative braking, the microprocessor 4 controls the converter 3 to take AC voltages from the alternator-starter 2 to, on the one hand, charge the battery 8, and on the other hand, power the electrical consumers of the vehicle.

The microprocessor 4 is also connected to a motor control unit 10 capable of managing the heat engine 9.

When the alternator-starter 2 does not deliver current, especially during a stopping phase of the engine stop / restart system 1, the battery 8 must alone meet the electrical needs of the vehicle.

In this case, the risks of a high and rapid discharge of the battery 8 are increased.

According to the invention, the control device 5 of the engine stop / restart system 1 comprises a control module 6 and sensors 7. The control module can be implanted at least partially in the microprocessor.

Alternatively, the control module may be implanted in a means for receiving the sensors, said means being able to be disposed near the battery. We will now describe in greater detail, with reference to FIGS. 2 to 1 1, the operation of the control module 6 according to the invention. More specifically, it is described in detail the control method of the invention implemented in this control module 6. FIG. 2 relates to a ST1 first stop engine authorization processing sub-module of the control module 6. This submodule ST1 is activated during parking and first start phases, and processes steps S100 to S1 of the method control to authorize a first stop (FSA = I) of the heat engine 14.

The parking stage occurs when there appears to be a stop of the engine 9 and a power failure of the vehicle (a key is removed) for a long enough time, for example 2 hours.

This duration allows the battery 4 to stabilize its energy state, both thermally and electrically.

In the particular embodiment of the method illustrated in FIG. 2, the control module 6 obtains at step S100 a current delivered by the battery 8, called Ibat in the remainder of the description.

The current Ibat comes from the sensors 7. It is for example measured using a shunt.

The current Ibat is then transmitted to a step S101.

Step S101 performs a comparison calculation between the current Ibat obtained in step S100 and a predetermined current threshold value, called Ic.

These steps S100 and S101 allow, during the parking phase, to control the amount of electrical energy supplied by the battery 8 to the electrical consumers.

If the comparison calculation performed in step S101 results in a current Ibat less than or equal to Ic, the control module 6 obtains at steps S102 and S103, respectively the temperature of the battery 8 and a voltage across the battery 8, respectively called Tbat and Ubat in the following description. The temperature Tbat obtained in step S102 and the voltage Ubat obtained in step S103 come from the sensors 7. The temperature Tbat corresponds to the internal temperature of the battery 8.

The sensors 7 include a temperature sensor for measuring the ambient temperature of the battery 8, and a means for calculating the internal temperature Tbat for extrapolating said internal temperature Tbat from the ambient temperature. Alternatively, it is possible to measure the internal temperature of the battery 8 directly by means of a temperature sensor positioned for example under the battery 8.

These temperature probes can for example be of the type "NTC" ("Negative Temperature Coefficient", in English), or of the type with negative coefficient resistance.

The temperature Tbat and the voltage Ubat are then transmitted to a step S104 for determining an energy state information of the battery 8.

Step S104 comprises a substep S1041 for determining a state of charge of battery 8 as a function of temperature Tbat and voltage Ubat. This state of charge is called SOC in the following description.

In the example considered, the state of charge SOC is read in a look-up table stored in the control module 6 from the temperature Tbat and the voltage Ubat, this look-up table containing a plurality of state of charge values associated with different temperatures Tbat and Ubat predetermined voltages. These state of charge values are calculated during preliminary tests.

The determined state of charge SOC is then stored at a substep S1042 in the control module 6.

The next step, if the parking phase continues, is a step S109 corresponding to a sleep mode. This standby mode corresponds to the repetition of steps S100 to S104 during the parking phase.

Indeed, when the parking phase is detected, the steps S100 to S104 are started, then said steps are repeated, for example 3 times, with a predetermined time interval, for example 30 minutes. Then, it is possible to repeat these steps again, for example 3 times, with a predetermined time interval, for example 24 hours.

Whenever a state of charge SOC is determined in substep S1041, it is stored in substep S1042 in control module 6.

If the comparison calculation performed in step S101 results in a current Ibat greater than Ic, then step S109 corresponding to the standby mode described above follows step S101.

If the first start phase appears, the control module 6 obtains in a step S105 the temperature Tbat, in the same manner as before, and transmits Tbat to a step S106. Step S106 performs a comparison calculation between this temperature Tbat and a predetermined temperature threshold value, called Tth. The threshold value Tth is for example of the order of -5 ° C.

If the comparison calculation results in a temperature Tbat lower than Tth, the control module 6 terminates the authorization processing sub-module first stop motor ST1 at a step S1 10.

If the comparison calculation results in a temperature Tbat greater than or equal to Tth, the control module 6 checks in a step S107 if a charge state SOC determined beforehand during a parking phase has been stored, in substeps S1041 and S1042 .

If no state of charge has been memorized, the control module 6 disables the authorization subprocessing module ST1 in step S110.

If a state of charge SOC has been memorized, the control module 6 continues the determination of the energy state information of the battery 8 by performing a comparison calculation with a substep S1043. This comparison calculation is performed between the state of charge SOC determined and stored in substeps S1041 and S1042, and a predetermined state of charge threshold value, called SOCth, for example of the order of 80%. If the comparison calculation results in a charging state SOC greater than or equal to SOCth, the control module 6 controls, at a step S108, the engine stop / restart system 1 via the microprocessor 4 to authorize a stop of the engine 14 (FSA = I). Step S108 has substep S1081.

Thus, the control module 6 authorizes the sub-step S1081 a stop (FSA = I) of the heat engine 14.

If the comparison calculation results in a SOC state of charge lower than SOCth, the control module 6 terminates the first stop engine authorization processing sub-module ST1 in step S1 10.

It should be noted that steps S105 and S106 can be executed in the different embodiments of the method according to the invention detailed below.

FIG. 3 relates to another embodiment of a ST2 first stopping authorization processing sub-module of the control module 6. This submodule ST2 is activated during the first start phase and deals with the steps S1 12 to S1 19 of the control method to authorize a first stop

(FSA = I) of the engine 14.

The control module 6 obtains at step S1 12 the temperature Tbat and transmits Tbat at a step S1 13.

Step S1 13 determines a reference voltage, called Uref, as a function of the temperature Tbat determined in step S1 12.

In the example considered, the reference voltage Uref is read in a look-up table stored in the control module 6 from the temperature Tbat, this look-up table containing a plurality of values associated with different predetermined temperatures Tbat.

The control module 6 also obtains in a step S114 the voltage U bat. Then, a step S1 performs a comparison calculation between the voltage Ubat and the reference voltage Uref determined.

If the comparison calculation results in a Ubat voltage different from Uref, the control module 6 deactivates the ST2 first stop authorization processing sub-module at a step S1 19.

If the comparison calculation results in a voltage Ubat substantially equal to Uref, the control module 6 obtains in a step S116 the current Ibat and transmits it to a next step S1 17 for determining the energy status information of the battery 8. Step S1 17 comprises substeps S1 171 and S1 172.

The substep S1 171 determines a current threshold value, called Ith, as a function of the temperature Tbat.

The threshold value Ith is read in a look-up table stored in the control module 6 from the temperature Tbat, this look-up table containing a plurality of values associated with different predetermined temperatures Tbat.

The current Ith is then transmitted to the substep S1 172 which performs a comparison calculation between the current Ibat and the threshold value Ith determined.

If the comparison calculation results in a current Ibat greater than Ith, the control module 6 terminates the authorization processing sub-module first stop motor ST2 in step S1 19.

If the comparison calculation results in a current Ibat less than or equal to Ith, the control module 6 controls, at a step S1 18, the stop / restart system motor 1 via the microprocessor 4 to allow a first stop (FSA = I) of the engine 14.

Step S1 18 comprises a substep S1 181.

The control module 6 authorizes in the substep S1 181 a stop (FSA = I) of the heat engine 14.

It should be noted that the steps S1 12 to S1 can be executed in the various embodiments of the method according to the invention detailed below, provided that the control module 6 includes an authorization processing sub-module. ST2 motor stop (FSA = I and / or SA = 1). Figure 4 relates to an engine stop ban processing sub-module

ST3 of the control module 6. This submodule ST3 is activated during a normal operating phase, following an authorization of a shutdown (FSA = I or SA = 1) of the heat engine 14, and deals with the steps S120 to S123 of the control process occurring during this phase, to prohibit a stop (SA = O) of the engine 14.

In a particular embodiment of the method, the control module 6 obtains at a step S120 the current Ibat and transmits it to a step S121 for determining the energy status information of the battery 8.

Step S121 includes substeps S121 1 and S1212. The substep S121 1 determines an energy balance of the battery 8, called

CB in the following description, according to the current Ibat.

The energy balance is determined by a sum of a quantity of incoming energy and a quantity of outgoing energy. These amounts of energy correspond to an integration of the current Ibat. In addition, a coefficient, called coefficient of efficiency, can be assigned to at least a quantity of energy.

The energy balance and its evolution over time are precisely determined thanks to the dynamical obtaining of the Ibat current. It should be noted that the energy balance CB is initialized by the control module 6 when a stop authorization (SA = 1) is controlled by this control module 6.

The control module 6 then performs a comparison calculation with the substep S1212 between the determined energy balance CB and a predetermined energy balance threshold value CBth2.

If the comparison calculation results in a CB energy balance higher than CBth2, the control module 6 deactivates the stopping inhibit processing sub-module ST3 at a step S123.

If the comparison calculation results in an energy balance CB less than or equal to CBth2, the control module 6 controls, in a step S122, the engine stop / restart system 1 via the microprocessor 4 to prohibit a stop (SA = O ) of the heat engine 14.

Step S122 includes substep S1221.

The control module 6 prohibits the sub-step S1221 a stop (SA = O) of the heat engine 14.

FIG. 5 relates to an ST4 engine stop enable processing sub-module of the control module 6. This submodule ST4 is activated during a normal operating phase, following a prohibition of an engine stop. (SA = O), and processes steps S124 to S129 of the control method occurring during this phase, to allow a shutdown (SA = 1) of the heat engine 14.

In a particular embodiment of the method, the control module 6 obtains at a step S124 the temperature Tbat and transmits it to a step S125 for determining the energy status information of the battery 8. The step S125 comprises substeps S1251 and S1252. The substep S1251 determines a current threshold value Ith, as a function of the temperature Tbat, the current Ith being read in the same manner as above. In addition, the control module 6 obtains the current Ibat at a step S126 and transmits it to the substep S1252.

The substep S1252 performs a comparison calculation between the current Ibat and the threshold value Ith determined.

In addition, the current Ibat obtained in step S126 is transmitted to a step S127 for determining the energy state information of the battery 8, this step S127 comprising substeps S1271 and S1272.

The substep S1271 determines the energy balance CB of the battery 8 as a function of the current Ibat obtained.

Sub-step S1272 performs a comparison calculation between the determined energy balance CB and a predetermined energy balance threshold value CBth3.

This threshold value CBth3 may be greater than the threshold value CBth2. If the comparison computation of the sub-step 1252 results in a current Ibat greater than Ith, the control module 6 terminates the stop processing authorization sub-module ST4 at a step S129.

If the comparison calculation of sub-step 1272 results in a CB energy balance lower than CBth3, the control module 6 deactivates the ST4 engine stop enable processing sub-module in step S129.

If the comparison calculations carried out in substeps S1272 and S1252 respectively result in an energy balance CB greater than or equal to CBth3 and in a current Ibat less than or equal to Ith, then the control module 6 controls, in a step S128, the motor stop / restart system 1 via the microprocessor 4 to allow a stop (SA = 1) of the heat engine 14. The step S128 comprises a substep S1281.

The control module 6 authorizes the sub-step S1281 a stop (SA = 1) of the heat engine 14. The energy balance CB is then initialized to a zero value.

In another particular embodiment of an ST5 engine stop enable processing sub-module of the control module 6, illustrated in FIG. 6, said sub-module ST5 is activated during a normal operating phase, as a result of a prohibition of an engine stop (SA = O). Said submodule ST5 processes steps S132 to S135 of the control method occurring during this phase, to allow a shutdown (SA = 1) of the heat engine 14.

In the example considered, the control module 6 obtains the current Ibat at a step S132 and transmits it to a step S133 for determining the information energy status of the battery 8.

Step S133 comprises substeps S1331 and S1332. The substep S1331 determines the energy balance CB of the battery 8 and transmits it to the substep S1332. The control module 6 then performs a comparison calculation with the sub-step S1212 between the determined energy balance CB and a predetermined energy balance threshold value CBth4.

This threshold value CBth4 can be positive or zero.

If the comparison calculation results in a CB energy balance lower than CBth4, the control module 6 deactivates the stopping authorization processing sub-module ST5 at a step S135.

If the comparison calculation results in an energy balance CB greater than or equal to CBth4, the control module 6 controls at a step S134 the engine stop / restart system 1 via the microprocessor 4 to allow a stop (SA = 1) of the heat engine 14.

Step S134 includes substep S1341.

The control module 6 authorizes the sub-step S1341 a stop (SA = 1) of the heat engine 14.

The energy balance CB is then initialized to a zero value. FIG. 7 relates to a request processing submodule ST6 of the control module 6. This submodule ST6 is activated during a normal operating phase, when the heat engine 14 is stopped, and deals with steps S138 to S141 of the control process occurring during this phase, to request a restart (RR = 1) of the heat engine 14.

In a particular embodiment of the method, the control module 6 obtains at a step S138 the voltage Ubat and transmits it to a step S139 for determining the energy state information of the battery 8. The step S139 comprises a substep S1391.

Sub-step S1391 performs a comparison calculation between the obtained voltage Ubat and a predetermined voltage threshold value, called Uth. For example the voltage Uth can be between 11, 5V and 12V for a 14V lead-acid battery.

If the comparison calculation results in a voltage Ubat greater than Uth, the control module 6 terminates the request processing submodule ST6 engine recovery request in a step S141.

If the comparison calculation results in a Ubat voltage less than or equal to Uth, the control module 6 controls, in a step 140, the engine stop / restart system 1 via the microprocessor 4 to request a restart (RR = 1) of the engine 14.

Step S140 includes a substep S1401.

The control module 6 authorizes in the substep S1401 a restart (RR = 1) of the heat engine 14.

In another particular embodiment of an ST7 engine restart request processing sub-module of the control module 6, illustrated in FIG. 8, said submodule ST7 is activated during a normal operating phase, when the heat engine 14 is stopped, and processes steps S144 to S147 of the control process occurring during this phase, to request a restart (RR = 1) of the engine 14.

In the example considered, the control module 6 obtains the current Ibat at a step S144 and transmits it to a step S145 for determining the energy status information of the battery 8.

Step S145 includes substeps S1451 and S1452. The substep S1451 determines the energy balance CB of the battery 8 and transmits it to the substep S1452. The control module 6 then performs a comparison calculation with the substep S1452 between the determined energy balance CB and a predetermined energy balance threshold value CBthi.

This threshold value CBthi may be lower than the threshold value CBth2. If the comparison calculation results in a CB energy balance higher than CBthi, the control module 6 deactivates the ST7 request restart processing sub-module at a step S147.

If the comparison calculation results in an energy balance CB less than or equal to CBthi, the control module 6 controls at a step S146 the engine stop / restart system 1 via the microprocessor 4 to request a restart (RR = 1) of the heat engine 14.

Step S146 includes a substep S1461.

The control module 6 authorizes in the substep S1461 a restart (RR = 1) of the heat engine 14. FIG. 9 relates to a canceling request processing sub-module ST8 of the control module 6. This submodule ST8 is activated during a normal operating phase, following a request for a restart of the engine. (RR = 1), and deals with steps S150 to S154 of the control process occurring during this phase, to cancel this restart request (RR = O) of the heat engine 14.

In a particular embodiment of the method, the control module 6 obtains at a step S150 the temperature Tbat and transmits it to a step S151 for determining the energy state information of the battery 8. The step S151 comprises substeps S151 1 and S1512.

The substep S151 1 determines a current threshold value Ith, as a function of the temperature Tbat, the current Ith being read in the same manner as above.

In addition, the control module 6 obtains at a step S152 the current Ibat and transmits it to the substep S1512.

The substep S1512 performs a comparison calculation between the current Ibat and the threshold value Ith determined.

If the comparison calculation results in a current Ibat greater than Ith, the control module 6 terminates the cancellation processing sub-module request restart motor ST8 at a step S154.

If the comparison calculation results in a current Ibat less than or equal to Ith, the control module 6 controls, in a step S153, the stop / restart system motor 1 via the microprocessor 4 to cancel a restart request (RR = 0) of the heat engine 14.

Step S153 includes substep S1531.

The control module 6 cancels in the substep S1531 a restart (RR = 0) of the heat engine 14.

In another particular embodiment of a cancellation request processing sub-module request ST9 engine restart of the control module 6, illustrated in FIG. 10, said submodule ST9 is activated during a normal operating phase, at the following a request for a restart of the engine (RR = 1). Said submodule ST9 deals with steps S157 to S160 of the control method occurring during this phase, to cancel the restart request (RR = O) of the heat engine 14.

In the example considered, the control module 6 obtains at a step S157 the current Ibat and transmits it to a step S158 for determining the energy status information of the battery 8.

Step S158 includes substeps S1581 and S1582. The substep S1581 determines the energy balance CB of the battery 8 and transmits it to the substep S1582.

The control module 6 then performs a comparison calculation with the substep S1582 between the determined energy balance CB and a predetermined energy balance threshold value CBth5.

This CBth5 threshold value can be positive or zero. If the comparison calculation results in a CB energy balance lower than CBth5, the control module 6 deactivates the cancel request processing submodule ST9 engine restart at a step S160.

If the comparison calculation results in a CB energy balance greater than or equal to CBth5, the control module 6 controls, in a step S159, the engine stop / restart system 1 via the microprocessor 4 to cancel a restart request (RR = O) of the heat engine 14. The step S159 comprises a substep S1591.

The control module 6 cancels in the substep S1591 a restart (RR = 0) of the engine 14.

Claims

claims

1. A method for controlling a motor stop / restart system (1) fitted to a motor vehicle, the method comprising steps of: - obtaining at least one parameter (Tbat, Ubat, Ibat) representative of a state of an energy storage unit (8),

- determining an energy status information of the energy storage unit (8) from said at least one parameter obtained (Tbat, Ubat, Ibat), and - controlling the engine stop / restart system (1) according to the determined energy state information, characterized in that the energy state information is initialized to a predetermined value when the method controls an authorization to stop the engine stop / restart system (1).

2. Method according to claim 1, characterized in that said parameter comprises at least one of the following parameters:

a temperature (Tbat) of the energy storage unit (8),

a voltage (Ubat) of the energy storage unit (8), a current (Ibat) of the energy storage unit (8).

3. Method according to claim 2, characterized in that the step of determining the energy state information comprises sub-steps of: determining a state of charge (SOC) as a function of the voltage (Ubat) and the temperature (Tbat) of the energy storage unit (8), and

comparing the determined state of charge (SOC) with a predetermined state of charge threshold value (SOCth).

4. Method according to one of claims 2 or 3, characterized in that the step of determining the energy state information comprises sub-steps of:

determining a current threshold value (Ith) as a function of the temperature (Tbat) of the energy storage unit (8), and - comparing the current (Ibat) of the energy storage unit ( 8) to the determined current threshold value (Ith).

5. Method according to any one of claims 2 to 4, characterized in that the step of determining the energy state information comprises sub-steps of:

determining an energy balance (CB) as a function of the current (Ibat) of the energy storage unit (8), and

comparing the determined energy balance (CB) with a predetermined energy balance threshold value (CBtM, CBth2, CBth3, CBth4, CBth5).

6. Method according to claim 2 or 3, characterized in that the step of determining the energy state information comprises a sub-step of comparing the voltage (Ubat) of the energy storage unit (8) to a predetermined voltage threshold value (Uth).

7. Method according to any one of claims 1 to 5, characterized in that the step of controlling the engine stop / restart system (1) comprises a substep of allowing a stopping of the engine.

8. Method according to claims 7 and 3, characterized in that the sub-step of authorizing a motor stop is performed when the state of charge (SOC) is greater than or equal to the threshold value of state of charge (SOCth) predetermined.

9. Method according to claims 7 and 4, characterized in that the sub-step of allowing a stopping of the motor is performed when the current (Ibat) of the energy storage unit (8) is less than or equal to the current threshold value (Ith) determined.

10. Process according to claims 7 and 5, characterized in that the sub-step of authorizing an engine stop is performed when the energy balance (CB) is greater than or equal to the predetermined energy balance threshold value (CBth4). .

The process according to claims 7, 5 and 4, characterized in that the sub step of authorizing an engine stop is performed when:

the energy balance (CB) is greater than or equal to the predetermined energy balance threshold value (CBth3), and

the current (Ibat) of the energy storage unit (8) is less than or equal to the determined current threshold value (Ith).

12. Method according to any one of claims 1 to 1 1, characterized in that the step of controlling the engine stop / restart system comprises a substep of prohibiting a stopping of the engine.

13. The method according to claims 12 and 5, characterized in that the sub-step of prohibiting stopping of the engine is performed when the energy balance (CB) is less than or equal to the predetermined energy balance threshold value (CBth2). .

14. A method according to any preceding claim except claim 4, characterized in that the step of controlling the engine stop / restart system comprises a substep of requesting a restart of the engine.

15. Method according to claims 14 and 6, characterized in that the substep of requesting a restart of the motor is performed when the voltage (Ubat) of the energy storage unit (8) is less than or equal to one predetermined voltage threshold value (Uth).

16. The method of claims 14 and 5, characterized in that the substep of requesting a restart of the motor is performed when the energy balance (CB) is less than or equal to the predetermined energy balance threshold value (CBthi).

17. A method according to any one of the preceding claims, except claim 6, characterized in that the step of controlling the engine stop / restart system comprises a substep of canceling a request to restart the engine.

18. The method according to claims 17 and 5, characterized in that the substep of canceling a request to restart the engine is performed when the energy balance (CB) is greater than or equal to the predetermined energy balance threshold value ( CBth5).

19. The method according to claims 17 and 4, characterized in that the substep of canceling a request to restart the engine is performed when the current (Ibat) of the energy storage unit (8) is lower or equal to the determined current threshold value (Ith).

20. Process according to any one of the preceding claims, characterized in that the step of determining the energy status information of the energy storage unit is preceded by a step of comparing the temperature (Tbat) of the energy storage unit (8) with a predetermined temperature threshold value (Tth).

21. Method according to any one of the preceding claims, except claim 6, characterized in that the step of determining the energy state information is preceded by steps of:

determining a reference voltage (Uref) as a function of the temperature (Tbat) of the energy storage unit (8), and

comparing the voltage (Ubat) of the energy storage unit (8) with the determined reference voltage (Uref).

22. A control device (5) for a motor stop / restart system (1) adapted to equip a motor vehicle, comprising a control module (6), said control module (6) comprising:

means for obtaining at least one parameter (Tbat, Ubat, Ibat) representative of a state of an energy storage unit (8),

means for determining energy state information of the energy storage unit (8) from said at least one parameter obtained (Tbat, Ubat, Ibat), and

means for controlling the engine stop / restart system (1) as a function of the determined energy state information.

23. Device (5) according to the preceding claim, said control module (6) is located at least partially in a control unit (4) and for controlling the engine stop / restart system (1).

24. Device (5) according to claims 22 or 23, characterized in that the means for obtaining at least one parameter (Tbat, Ubat, Ibat) representative of a state of a energy storage unit comprises sensors ( 7) provided to obtain at least one of the following parameters:

a temperature (Tbat) of the energy storage unit (8), a voltage (Ubat) of the energy storage unit (8),

a current (Ibat) of the energy storage unit (8).

Motor stop / restart system (1) comprising a rotary electric machine (2), a reversible analog-digital converter (3) and control means of the control device (5) according to any one of claims 22 to 22. 24.

26. Stop / restart system engine (1) according to claim 25, characterized in that the rotating electrical machine (2) is an altemo-starter.

Motor vehicle comprising an engine stop / restart system (1) according to claim 25 or 26.