WO2016124834A1

WO2016124834A1 - Method for controlling the automatic stop and restart function of an internal combustion engine

Info

Publication number: WO2016124834A1
Application number: PCT/FR2016/050128
Authority: WO
Inventors: Alex MALOT; Fanny CHABARDES; Caroline DE BRAUER
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2015-02-02
Filing date: 2016-01-22
Publication date: 2016-08-11
Also published as: EP3253963A1; CN107531240A; FR3032164B1; FR3032164A1

Abstract

A method for managing an internal combustion engine (2) of a motor vehicle (1), the vehicle (1) comprising: - a brake pedal (5), and - an automatic gearbox (6) that can adopt a parking position allowing the drive wheels of the vehicle (1) to be blocked when parked, said method comprising a step of analysing the state of the engine (2), the brake pedal (5) and the gearbox (6) such that: - if the engine is off, the gearbox (6) in the parking position (P) and the brake pedal (5) pressed down, the engine (2) is restarted, and - if the engine is running, the brake pedal (5) pressed down, the gearbox (6) in the parking position and the brake pedal (5) is released, the engine (2) is stopped.

Description

METHOD FOR CONTROLLING STOP AND RESTART FUNCTION

AUTOMATIC INTERNAL COMBUSTION ENGINE

The invention relates to the field of internal combustion engines of motor vehicles and more particularly to the management of the stop and start of these engines including engines equipped with an automatic stop and restart system. , and an automatic or robotic gearbox.

To limit fuel consumption and the release of polluting particles into the atmosphere, it is known to stop the engine when the vehicle is stationary. For example, when the stopping time of a vehicle exceeds three seconds, the engine is stopped and restarted when the driver acts on one of the controls of the vehicle.

On a vehicle equipped with an automatic gearbox, when the gearbox is in a position corresponding to a reverse gear of the vehicle, the stop and restart system can be disabled since the stops are frequent and of short duration.

When the gearbox is in a position corresponding to a neutral or parking position, the automatic stop and restart system may allow and / or maintain the engine stop since the vehicle is immobilized.

Finally, when the gearbox is in a position corresponding to a rolling position, the stop and restart system may allow stopping, maintaining the stop and / or restart the engine.

The document FR 2 995 835 discloses a stop and restart management method of a motor vehicle engine, this method comprising a main step of taking into account the activated or deactivated position of the parking brake and the the action of the driver on the brake pedal. In addition, in underlying process steps, the position of the gearbox and the state of depression of the clutch pedal, if any, may be taken into account to stop or restart the engine.

If this method stops and restart the engine, it has some disadvantages. [0008] Firstly, this method is based on a series of steps taken into account of certain parameters which involves a computer having a large processing capacity. In addition, this method is long to implement and does not allow a fast response time. Thus, the driver can not enjoy optimal torque as soon as he wants to move the vehicle.

Secondly, taking into account the state of the parking brake is an obstacle to the implementation of the method. For a manual parking brake, it is common that the action of the driver is not complete, for example by inattention or manipulation too fast handle, and the parking brake is not fully loosened. This incomplete action does not prevent the movement of the vehicle but generates a signal indicating to the driver that the parking brake is not completely loosened and prematurely wears the parking brake. For an automatic parking brake requiring a torque threshold value to be exceeded in order to deactivate the parking brake, the motor can not be restarted and thus generate the torque necessary to deactivate the parking brake, deactivation of the parking brake automatic operation is necessary for restarting the engine.

In the following text, we will use the term automatic gearbox to designate both automatic and robotic gearboxes.

A first objective is to provide a method of managing the shutdown and restart of a motor vehicle internal combustion engine, which is fast and does not require large resources for its implementation.

A second objective is to provide a method for managing the shutdown and restart of an internal combustion engine of a motor vehicle, simple design and adaptation for different engines.

A third objective is to provide a method for managing the stopping and restarting of an internal combustion engine of a motor vehicle, which anticipates the will of the driver to restart to ensure optimal torque as soon as the user wishes move the vehicle. A fourth objective is to provide a motor vehicle comprising an internal combustion engine and a computer for implementing a method for managing the stopping and restarting of an internal combustion engine meeting the above objectives.

For this purpose, it is proposed, in the first place, a management method of an internal combustion engine of a motor vehicle, the vehicle comprising:

a brake pedal which can adopt a depressed position to brake the vehicle and a relaxed position having no influence on the vehicle, and

an automatic gearbox capable of adopting a driving position to allow the vehicle to move forward, a recoil position to allow the vehicle to retreat, a neutral position to separate the engine from a driving circuit of the vehicle, and a parking position for locking the drive wheels of the vehicle during a parking, this method comprising a step of analyzing the state of the engine, the brake pedal and the gearbox so that if the engine is switched off, when a driver of the vehicle places the transmission in parking position and depresses the brake pedal, then the engine is restarted.

Advantageously, if the engine is started, that the driver depresses the brake pedal, the driver positions the gearbox in parking position from the driving position, the recoil position or the neutral position and that the driver release the brake pedal, then the engine is stopped.

The only taking into account of the state parameters of the engine, the brake and the gearbox makes it possible to increase the reactivity of the computer, to promote a switch-off or a quick restart of the engine and to anticipate the will of restarting a driver of the vehicle to provide a nominal torque to the driver.

It is proposed, secondly, a computer for the implementation of the method as described above, the computer being coupled to the bodies of a motor vehicle. Advantageously, the computer comprises four inputs and two outputs.

It is proposed, third, a motor vehicle comprising an internal combustion engine, a battery, a brake pedal, an automatic gearbox and a computer capable of implementing the previously described method.

Other features and advantages of the invention will appear more clearly and in a concrete manner on reading the following description of embodiments, which is made with reference to the accompanying drawings in which:

Figure 1 is a schematic view showing the connections between a computer and different bodies of a motor vehicle;

Figure 2 is a timing chart showing the state of different members of Figure 1 according to a first use configuration; - Figure 3 is a timing chart showing the state of different members of Figure 1 according to a second use configuration.

In Figure 1 is shown, schematically, a vehicle 1 automobile comprising an internal combustion engine 2, a computer 3, a battery 4, a brake pedal 5, a gearbox 6 and a tachometer 7.

The gearbox 6 is a 6 automatic gearbox whose different positions will be described below.

The vehicle 1 is equipped with an automatic stop and restart system that stops the engine 2 when the vehicle 1 is stopped, in order to reduce fuel consumption and limit the discharge of polluting particles into the atmosphere.

The stop and restart system is controlled by the computer 3 and is activated or deactivated according to a threshold speed of the vehicle 1. For example, when the instantaneous speed of the vehicle 1 is greater than the threshold speed, the stopping and restarting system is deactivated, whereas when the instantaneous speed of the vehicle 1 is below the threshold value, the stopping and restarting system is activated. The instantaneous speed of the vehicle 1 is supplied to the computer 3 by the tachometer 7. As seen in Figure 1, the computer 3 comprises four inputs and two outputs, the four inputs being connected to the tachometer 7, the brake pedal 5, the engine 2 and the gearbox 6, the two outputs being connected to the battery 4 and the engine 2.

More specifically, the connection between the computer 3 and the brake pedal 5 is via a brake sensor F to provide a binary signal on the depression state of the brake pedal 5, namely a signal 0 if the brake pedal 5 is not depressed, and a signal 1 if the brake pedal 5 is depressed.

Similarly, the connection between the gearbox 6 and the computer 3 is via a box P sensor for providing a binary signal on the state of a position of the gearbox 6, namely a signal 0 if the gearbox 6 is in a neutral position N to dissociate the motor 2 of a drive circuit (not shown) of the vehicle 1, in a recoil position R allowing the recoil of the vehicle 1 or a position D driving allowing the vehicle 1 to move forward, and a signal 1 if the gearbox 6 is in a parking position P to block the drive wheels of the vehicle 1 during parking.

The word parking is a word of English origin which means that the vehicle 1 is in a condition in which the vehicle 1 does not move.

The link between the computer 3 and the battery 4 is a schematic modeling of a starting circuit of the engine 2. In reality, the computer 3 sends a start command to a starter (not shown for simplification purposes) 4. As soon as the start command is received by the starter, the starter draws in the battery 4 the energy necessary to provide a starting torque to the engine 2.

With the aid of information from the brake sensor F and the box sensor P, the computer 3 can execute a step of a management method of stopping and restarting the engine 2, so as to realize a stop A of the engine 2 or a restart RD of the engine 2 from the analysis of the state of the brake sensor F, the P-box sensor and the state of the engine 2. The timing diagrams of Figures 2 and 3 show the stop A and restart RD of the engine 2 generated by the computer 3 from the information of the brake sensor F and the P-box sensor.

As can be seen in phase IV of the timing diagram of FIG. 2, the engine 2 is restarted if:

the engine 2 is stopped (A = 1);

the driver presses the brake pedal 5 (F = 1), and the gearbox 6 is in the parking position (P = 1).

Thus, if the vehicle 1 is parked, with the engine 2 stopped (A = 1) and the gearbox 6 in the parking position P, the RD restart of the engine 2 is automatically activated if the driver presses on the brake pedal 5. The pressing of the brake pedal 5 is mandatory, for safety reasons, to release the lever from the position P, therefore before the RD restart of the engine 2, in order to avoid putting the vehicle 1 into motion during the RD restart. , which could cause a collision between the vehicle 1 and a wall, for example, or a pedestrian passing near the vehicle 1.

However, as seen in phase II of the timing diagram of FIG. 2, the engine 2 is stopped if:

the engine 2 is in operation;

the driver releases the brake pedal 5 (F = 0), and the driver positions the gearbox 6 is in the parking position (P = 1).

Thus, if the driver immobilizes the vehicle, engine 2 in operation and brake pedal 5 depressed, then positions the gearbox 6 on the parking position P, then the release of the brake pedal 5 causes the stop A of the engine 2.

As seen in phase I of Figure 2, if the user positions the gearbox 6 in parking position P, and that the engine 2 is in operation, it is sufficient for the driver to push and then release the brake pedal 5, or release the brake pedal 5 if the brake pedal 5 was already depressed, to allow the stopping of the engine 2.

According to these two configurations, in the parking position P, the stop A of the engine 2 is effective until the driver engages not the brake pedal 5, and the stop A of the engine 2 intervenes only if the driver releases the brake pedal 5.

The chronograms of the chronogram of FIG. 2 are chronologically described.

In phase I, the engine 2 is turned on, the driver depresses the brake pedal 5, positions the gearbox 6 on the parking position P and then releases the brake pedal 5. This results in a stop A of the engine 2.

The phases II and III respectively represent the decrease of the torque C of the engine 2 and the total absence of torque C. During the phases II and III, the gearbox 6 is maintained in the parking position P and the pedal 5 of brake is released.

Finally, phase IV shows a depression of the brake pedal 5 by the driver, which coincides with a restart RD of the engine 2 until the nominal torque C of the engine 2 is reached.

Thus, when the driver positions the gearbox 6 in a position other than the parking position P, the available torque C is the nominal torque C of the motor 2.

Thus, as seen in the timing diagram of Figure 3, and more particularly on phase III, if the driver of the vehicle 1 does not engage the brake pedal 5 (F = 0) and then positions the box 6 in the parking position P (P = 0) and that the engine 2 is stopped, the engine 2 is not restarted (RD = 0). To allow the RD restart of the engine 2, the driver will then have to press the brake pedal 5 (F = 1).

The different phases of the chronogram of FIG. 3 are chronologically described.

In phase I, the engine 2 is on, the driver releases the brake pedal 5 and the gearbox 6 is in the neutral position N. This results in a stop A of the engine 2.

In phase II, there is a decrease in the torque C of the engine 2 until complete absence of torque C.

In phase III, the driver positions the speed box 6 in parking position P without acting on the brake pedal 5. The engine 2 then remains stopped until the driver depresses the brake pedal 5 as can be seen in phase IV. It then results a restart RD of the engine 2 and an increase of the torque C until the nominal torque C.

As can be seen in the timing diagrams of Figures 2 and 3, the driver RD restart will be anticipated. In advance, it is understood that when the driver wishes to position the gearbox 6 in the rolling position D or recoil position R, the nominal torque C offered by the engine 2 will be available. Thus, the beginning of the increase phase of the torque C coincides with the detection of the depression of the brake pedal 5 and the RD restart of the vehicle 1.

It then results in a good responsiveness of the vehicle 1 to the wish of acceleration of the driver and better conditions of use of the vehicle 1 for the driver.

In addition, the stop function and automatic restart of the vehicle 1 is preserved and even improved since it can work even if the vehicle 1 is equipped with a manual parking brake and the driver does not disable it or not entirely.

Finally, it will be noted that when the engine 2 is stopped (A = 1) and the driver depresses the brake pedal 5 (F = 1), then the passage of the gearbox 6 of the position D of driving at the parking position P does not cause the engine 2 to restart (RD = 0) when the brake pedal 5 is released (F = 0).

Claims

A method of managing a motor vehicle internal combustion engine (1), the vehicle (1) comprising:

a brake pedal (5) able to adopt a depressed position to brake the vehicle (1) and a relaxed position having no influence on the vehicle (1), and

an automatic gearbox (6) capable of adopting a rolling position (D) to allow the vehicle to move (1) forward, a recoil position (R) to allow the vehicle to retreat (1), a position ( N) neutral for separating the motor (2) from a drive circuit of the vehicle (1), and a parking position (P) for locking the driving wheels of the vehicle (1) during parking, characterized in that this method comprises a step of analyzing the state of the engine (2), the brake pedal (5) and the gearbox (6) so that if the engine is off, a driver of the vehicle (1) places the gearbox (6) in parking position (P) and depresses the brake pedal (5), then the engine (2) is restarted.

2. Management method according to claim 1, characterized in that if the engine is started, that the driver depresses the brake pedal (5), the driver positions the gearbox (6) in position (P) parking from the rolling position (D), the recoil position (R) or the neutral position (N) and that the driver releases the brake pedal (5), then the engine (2) is stopped.

3. Calculator (3) for implementing the method according to claim 1 or claim 2, the computer (3) being coupled to members of an automobile vehicle (1).

4. Vehicle (1) automobile comprising an internal combustion engine (2), a battery (4), a brake pedal (5), an automatic gearbox (6) and a computer (3) according to claim 3.