EP2901007A1

EP2901007A1 - Method and device for managing the stopping and restarting of a motor vehicle engine and motor vehicle engine including such a device

Info

Publication number: EP2901007A1
Application number: EP13779294.1A
Authority: EP
Inventors: Arnaud BOULICOT
Original assignee: Renault SAS
Current assignee: Renault SAS
Priority date: 2012-09-27
Filing date: 2013-09-25
Publication date: 2015-08-05
Also published as: CN104837703A; FR2995835A1; FR2995835B1; WO2014049264A1

Abstract

The invention relates to a method for managing the stopping (200) and restarting (203) of a motor vehicle engine, including, when a gearbox selector of said vehicle is in a neutral state (205) and the brake pedal is in a released state: receiving a value of a first parameter indicating the state of a brake pedal of the vehicle, and a value of a second parameter indicating the state of a parking brake of said motor vehicle, and, if the value of the first parameter corresponds to a released state of the brake pedal, generating (203) a signal for controlling the motor vehicle engine, having a value corresponding to a restart if the value of the second parameter corresponds to a released state of the parking brake (207, N), generating (200) a control signal of the engine, having a value corresponding to a stop if the value of the second parameter corresponds to an applied state of the parking brake (207, 0), and sending the resulting generated signal to the engine in order to control the stopping (200) and restarting (203) of said engine.

Description

METHOD AND DEVICE FOR STOPPING AND RESTARTING AN ENGINE

OF A MOTOR VEHICLE AND A MOTOR VEHICLE COMPRISING SUCH

DEVICE

The invention relates to stopping and restarting management of a motor vehicle engine, in particular a motor vehicle equipped with an automatic stop and start system, and a automatic transmission.

It is known to control a motor vehicle engine so that when the speed of the vehicle passes below a threshold, for example 6 kilometers / hour, the clutch is open, transmission to neutral and the engine goes into a state Eve. If the brake pedal is released later, the engine will restart. Such an automatic stopping and restarting system can save fuel because, when the stopping of the vehicle exceeds a given time, for example 3 seconds, it is advantageous, in terms of fuel consumption, to stop the fuel. engine.

Also known are the automatic transmission systems, for example automatic gearboxes or BVA, in which the driver chooses an operating position.

For an operating position corresponding to a reverse gear, the Stop and Start system can be deactivated because the stopping of the vehicle, when the latter is operating in reverse, generally have relatively short durations.

For a parking garage or parking position, the Stop and Start system can maintain the engine stop because the vehicle is in fact immobilized.

On the other hand, for a driving position or Drive, the Stop and Start strategy is activated and manages the motor stops and restarts dynamically.

Finally, for a Neutral position, it is known to let the Stop and Start strategy activated, engine stopped. Thus, when the user releases the brake pedal, the vehicle restarts.

It is also known to keep the engine stopped by the Stop and Start strategy when the transmission system is in a neutral engaged state. Thus, although the driver releases the brake pedal, the vehicle is kept at a standstill. This strategy can be tricky in that, if the vehicle moves because of the slope on the ground (especially in case of false flat), the driver will probably have to apply the brake pedal and consume the reserves of the braking assistance.

There is therefore a need for an engine management strategy, especially when the transmission system is in a neutral state, which would reconcile fuel economy and braking assistance.

There is provided a stop and restart management method of a motor vehicle engine, comprising, when a gear selector of this vehicle is in a neutral state, for example when the gear selector is on the position "N":

receiving a value of a first parameter indicative of the state of a brake pedal of this motor vehicle, and a value of a second parameter indicative of the state of a parking brake of this motor vehicle,

if the value of the first parameter corresponds to a released state of the brake pedal, generating an engine control signal according to the value of the second parameter received, and

- Send the signal thus generated to the engine to control the shutdown and restart of this engine.

Thus, if the gearbox selector is in neutral and the brake pedal is released, the parking brake state is taken into account to decide whether to restart / stop, or whether to maintain it stopped / running. of the motor.

By "arrested" also means "on standby".

For example, a motor control signal of this motor vehicle having a value corresponding to a restart / maintenance on is generated if the value of the second parameter corresponds to a released state of the parking brake and a control signal of the motor having a value corresponding to a stop / hold stopped if the value of the second parameter corresponds to a tight state of the parking brake.

If the driver has in fact placed the transmission in neutral and engaged the parking brake, for example a parking brake or an assisted parking brake, then it is considered that the vehicle must remain in place, and the engine is in standby. On the other hand, if the driver selected the Neutral position without tightening the parking brake, then it is considered that the driver will not oppose a possible restart: if the foot of the brake pedal is raised, the engine leaves the standby state.

In other words, the information provided by the state of the parking brake is used to better interpret the driver's will and adapt the strategy for restarting the engine. This can help to avoid restarting when the driver obviously wants to stay at a standstill, and thus save fuel.

This can further prevent a stopping or stopping when the driver has simply selected the Neutral position of the transmission, without applying the parking brake. It is thus possible to limit the drifting situations of the vehicle, likely to lead to a solicitation of the brake pedal consuming braking assistance.

Advantageously and without limitation, the vehicle may be equipped with an automatic stop and restart system. This system may for example comprise a reversible alternator.

For example, the method may comprise an authorization step of the automatic stop and restart system, if the second parameter has a value corresponding to a loose parking brake. In this case, it may be the automatic stop and restart strategy that controls the starting, for example if the first parameter corresponds to a relaxed state of the brake pedal.

In another example, the generation of the control signal is part of an automatic stop and restart strategy, furthermore providing that in the driving mode, the engine is put into a standby state when the speed falls below a threshold and restart the engine if the brake pedal is released.

In a non-limiting embodiment, the method described above is executed only if the speed of the vehicle is below a threshold, for example 6 km / h.

Advantageously and without limitation, the vehicle transmission system may be automatic. It can for example be an automatic gearbox or BVA, a robotic gearbox or BVR, or other. The process described above can thus to better interpret the driver's will when the driver is in neutral.

The invention can find a particularly interesting application in the context of vehicles equipped with robotized gearboxes, in which the driver has only three lever positions: driving, neutral, or reverse. Thus in such systems devoid of vehicle parking position (Parking), taking into account the information provided by the parking brake can better interpret the will of the driver, especially since the neutral position may be requested more frequently than in the case of a vehicle equipped with an automatic gearbox.

The method described above may be implemented by digital signal processing means, for example a processor, a microcontroller or the like.

There is further provided a computer program product comprising instructions for performing the method steps described above. This computer program product can be read on hard disk, downloaded or other type of computer support.

It is further proposed a management device for stopping and restarting a motor vehicle engine, comprising:

means for receiving a value of a first parameter indicative of the state of a brake pedal of this motor vehicle, and a value of a second parameter indicative of the state of a parking brake of this motor vehicle,

processing means arranged for, when a transmission selector of this vehicle is in a neutral state and the value of the first parameter corresponds to a released state of the brake pedal, generating a control signal of the engine of this motor vehicle according to the value of the second parameter, and

transmission means for sending the signal generated by the processing means to the motor to control the stopping and restarting of this engine.

This device can include or be integrated in a processor, for example a microcontroller, a microprocessor or other. The reception means may for example comprise an input port, an input pin or the like. The processing means may for example comprise a CPU core (of the English "Central Processing Unit"). Finally, the transmission means may for example comprise an output pin, an output port or the like.

It is further provided a motor vehicle comprising a management system as described above. This motor vehicle may advantageously include an automatic stop and start system or Stop and Start, and / or an automatic transmission system.

The invention will be better understood with reference to the figures, which illustrate non-limiting embodiments.

Figure 1 shows an example of a vehicle according to one embodiment of the invention.

Fig. 2 is a flowchart of an exemplary method according to one embodiment of the invention.

With reference to FIG. 1, a motor vehicle 1 is equipped with a motor 1 1 and an automatic stop and restart system. This system can be integrated in the processor 10 described below.

Depending on the type of transmission used in the vehicle equipped with a Stop & Start system, the driver may end up having to make an effort to keep the engine of his vehicle in automatic shutdown and save fuel in the period of time. immobilization.

For a vehicle equipped with a manual transmission system, it is sufficient for the driver to put his gear lever in neutral and release his clutch pedal so that the automatic engine stop is achieved or maintained.

For a vehicle equipped with an automatic gearbox, with a position P (for 'Parking') to block the transmission and immobilize the vehicle, no special effort on the part of the driver is necessary. It is sufficient for the driver to engage the P position when the engine is in automatic stop.

When the automatic transmission is not equipped with a P position or the driver does not use this position of the transmission, as is the case when the vehicle is equipped with a robotic gearbox, in the prior art, the driver must maintain a pressure on the brake pedal, otherwise the engine restarts, thus exiting the state of the automatic stop by the system Stop and Start. It is known to impose a maintenance of the automatic engine stop when the selector is in neutral and the brake pedal is released. However, when the vehicle is on a non-horizontal plane, that is to say for example if there is a slight slope, there may be a drift of the vehicle, and the driver will have to decide to keep the vehicle immobilized , while braking assistance is limited here.

To return to Figure 1, the vehicle 1 is equipped with a management device 10 of the engine 1 1, for example a microcontroller. The management device 10 receives BPedal signals from a position sensor of the not shown brake pedal, for example an acquisition module 12 in communication with this sensor.

The management device 10 also receives ParkingB signals from a module 13 in communication with a sensor capable of measuring a state of the parking brake.

The parking brake may for example include a handbrake, or FPM for Manual Parking Brake, or even a Parking Brake Assisted or FPA. In the case of an assisted parking brake, an electronic control unit or ECU can control the parking brake. The module 13 can then include this electronic control unit.

Finally, the management device 10 receives Selector signals from a management module of the automatic transmission system 14. These Selector signals can thus indicate the position of the selector of the automatic gearbox, for example reverse gear or R, neutral or N, driving or D, or manual or M.

When the vehicle 1 is at low speeds or at zero speed while being in neutral, the management device makes it possible to manage the automatic transition to a state of engine standby, according to the signals from the modules 12, 13, 14. , the management device 10 makes it possible to control the eventual restart of the motor 1 1, again as a function of the signals coming from the modules 12, 13, 14.

The flowchart of FIG. 2 corresponds to an exemplary method executed by the management device 10. When the gearbox selector is in a neutral state and the brake pedal is released, rather than making a final choice of operation of the Stop and Start system, the management device 10 takes into account the ParkingB signals from a sensor status of the parking brake, to adapt the operation of the Stop and Start system.

When the vehicle is stationary with the automatic transmission selector in neutral, the foot on the brake pedal, the parking brake being released, and the engine in automatic stop, and that the driver releases the brake pedal, then the engine is restarted by the Stop and Start system, in order to provide braking assistance, as it is then assumed that the driving resumes.

On the other hand, when the vehicle is stationary, with the automatic transmission selector in neutral, the driver's foot being on the brake, the parking brake being applied, the engine in automatic stop, and that the driver releases the pedal brake, then the engine remains in automatic engine stop and the vehicle remains immobilized. This can save fuel and limit the emission of gaseous pollutants, without endangering the passengers of the vehicle.

With reference to FIG. 2, when the vehicle is in an automatic engine stop state, as represented by step 200, the management device 10 tests during a step 201 whether the selector is in the driving position (D ), or in manual clutch position (M). This step can be performed based on the Selector values received from the module 14 during a not shown reception step. For example, during this step 201, the value of the variable Selector can be compared to two predetermined values, corresponding to the positions D and M, respectively. The test is positive in case of equality with one of these predetermined values.

If it turns out that the selector of the gearbox is in a driving state or in a manual clutch state, then during a step 202 a value of a first parameter corresponding to a state of the brake pedal, for example a value of the parameter BPedal from the module 12 (and received during a step not shown), to a predetermined value, for example 1, to estimate whether the brake pedal is in a supported state or not. If it turns out that the driver is pressing the brake pedal, then the vehicle is kept in a stopped state.

Step 200 is followed by an unrepresented step of transmitting a control signal to the engine to keep the engine in a sleep state.

Conversely, if it turns out that the brake pedal is in a relaxed state, then the engine can restart. The management device 10 generates a restart control signal for the motor 1 1. This is represented by the step 203. This step 203 is followed by a step (not shown) of transmission of a control signal towards the motor in order to to restart the engine.

To return to the test 201, if it turns out that the selector is neither in position D nor in position M, then one compares during a test 204 the value of the variable Selector from the module 14 to a value corresponding to position P.

If it turns out that the selector is in the parking position, then the engine stop is maintained.

In the opposite case, during a test 205, the value of the variable Selector received from the module 14 is compared to a value corresponding to the neutral.

If it turns out that this test 205 is negative, it is tested if the selector is at a position corresponding to the reverse (R), during a test 208. If this test is positive, then we disable the Stop & Start and the engine is restarted to allow recovery of driving in reverse. If the test is negative, then the engine stop is maintained, and a malfunction alert is triggered.

In the case where the test 205 is positive, that is to say if the vehicle is in neutral, then we compare during a step 206 the value of the variable BPedal, from the module 12, to a value corresponding to a position of support of the brake pedal, for example 1 or other.

If it turns out that the brake pedal is pressed, then the vehicle engine remains stopped.

On the other hand, if the brake pedal is released, then during a step 207 a value of a ParkingB variable (received during a step not shown) is compared to a predetermined value, corresponding to a brake application. parking. If the test 207 shows that the parking brake is tight, then the engine of the vehicle is stopped, even though the vehicle is in neutral, and the brake pedal is released.

In a way, we use the state of the brake pedal to interpret the will of the driver.

Conversely, if the test 207 is negative, that is to say that the parking brake is released, then the strategy of stopping and automatic restart is reactivated during the step 203, and the vehicle can restart .

The flowchart of FIG. 2 has been described as relating to a method for exiting the automatic shutdown state. A similar flow chart may be provided for the eventual entry into the state of automatic shutdown of the engine, except that the initial step 200 would then be a step corresponding to a maintenance control of the engine turned on, and that:

if the selector is in position M or D, it is the support on the brake pedal which determines the control of the motor (stop or maintenance in the lit state),

if the selector is in position P, then it commands an automatic shutdown of the motor,

if the selector is in position R, the engine is kept on (no automatic stop in reverse), and if the selector is in position N, then the engine control depends on both the state of the pedal of the engine. brake and the condition of the parking brake. Specifically, if the brake pedal is pressed, it commands an automatic shutdown of the engine, regardless of the position of the parking brake; If this is not the case, the engine is stopped automatically if the parking brake is applied and the ignition is switched on if the parking brake is released.

The method claimed below thus covers both the automatic standby of the engine and the output of this standby state.

Claims

A method for stopping and restarting a motor vehicle engine, comprising, when a gear selector of this vehicle is in a neutral state:

receiving a value of a first parameter (BPedal) indicative of the state of a brake pedal of the motor vehicle, and a value of a second parameter (ParkingB) indicative of the state of a parking brake of said vehicle automotive,

if the value of the first parameter corresponds to a released state of the brake pedal, generating (206, 207, 200, 203) a control signal of the engine of the motor vehicle according to the value of the second parameter, and

send the signal thus generated to the engine to control the shutdown and restart of this engine.

2. The method of claim 1, wherein receives a value of a third parameter representative of the state of a robotized or automatic gearbox.

3. Method according to one of claims 1 to 2, wherein the second parameter (ParkingB) is indicative of the state of a parking brake assisted motor vehicle (1) or the state of a brake to hand of the motor vehicle (1).

4. Method according to one of claims 1 to 3, comprising, when the selector is in the neutral state and the value of the first parameter corresponds to a relaxed state of the brake pedal:

generating (203) a control signal of the engine of the motor vehicle having a value corresponding to a restart or a maintenance on if the value of the second parameter corresponds to a released state of the parking brake, and

generating (200) a motor control signal having a value corresponding to a stopped or stopped hold if the value of the second parameter corresponds to a tight state of the parking brake.

5. Method according to one of claims 1 to 4, comprising, when the selector gearbox is in a driving state and the vehicle speed is below a threshold:

generating (202, 200, 203) the motor control signal as a function of the value of the first parameter (BPedal).

6. Device for stopping and restarting management (10) of a motor vehicle engine (1 1), comprising:

means for receiving a value of a first parameter (BPedal) indicative of the state of a brake pedal of this motor vehicle, and a value of a second parameter (ParkingB) indicative of the state of a parking brake of this motor vehicle,

processing means arranged for, when a transmission selector of this vehicle is in a neutral state and the value of the first parameter corresponds to a released state of the brake pedal, generating a control signal of the vehicle engine according to the value of the second parameter, and

transmission means for sending the signal generated by the processing means to the motor to control the stopping and restarting of said motor.

7. Motor vehicle (1) comprising a management device (10) according to claim 6.

8. Motor vehicle (1) according to claim 7, wherein the gearbox is automatic.

9. Motor vehicle (1) according to claim 8, wherein the transmission system comprises a robotized gearbox.

10. Motor vehicle (1) according to one of claims 7 to 9, further comprising an automatic stop and restart system operating at least when the gear selector is in a driving state.