WO2013175092A1

WO2013175092A1 - Automatic stop/start control system for a motor vehicle engine having an improved viability

Info

Publication number: WO2013175092A1
Application number: PCT/FR2013/050857
Authority: WO
Inventors: Fabrice Grisi; Thierry Hecketsweiler
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2012-05-22
Filing date: 2013-04-18
Publication date: 2013-11-28
Also published as: FR2990997A1; FR2990997B1; CN104603448A; EP2852757A1

Abstract

The invention relates to an automatic start and/or stop control device (10, 20, 30, 40) for a motor vehicle combustion engine, which takes into account (10) a result outputted by a detector (40) of a vehicle that precedes the vehicle provided with the control device, such as to initiate the stop and/or start of the engine depending on said result.

Description

AUTOMATIC STOP CONTROL AND STARTING SYSTEM OF A MOTOR VEHICLE MOTOR WITH IMPROVED RENTABILITY

The invention relates to the automatic control devices for stopping and / or starting a combustion engine of a motor vehicle also called "stop and start" starting devices according to the English terminology.

The "Stop and Start" is to stop the engine when its operation is not essential and restart the engine as soon as possible when the driver needs it again.

Stopping and restarting the engine represents an energy cost, corresponding to two or three seconds of fuel consumption at engine idling. All engine stops below this time therefore have a detrimental impact on the overall fuel consumption of the vehicle.

In some applications, for example for a vehicle equipped with an automated gearbox, the driver is not master of the stop of his engine by the stop and start function because the action he performs for slowing down the vehicle is synonymous with engine stop request when the speed becomes low, this is the case for example of pressing the brake pedal at a speed less than 5 Km / h.

These engine stops unwanted by the driver often result in imminent restarts, resulting in inconvenience of the driver to which is added an adverse energy balance because the engine stop lasted very shortly.

The invention aims to remedy these drawbacks.

This object is achieved according to the invention by means of an automatic control device for starting and / or stopping a combustion engine of a motor vehicle, which device takes into account at least one action of a driver of the vehicle of in such a way as to initiate the stopping and / or starting of the engine according to the presence of this action of the driver, characterized in that the device also takes into account a result delivered by a vehicle detector preceding the vehicle equipped by the command so as to initiate the stopping and / or starting of the engine according to this result.

Advantageously, the device takes into account a speed of the preceding vehicle to trigger a stop and / or start of the engine.

Advantageously, the device takes into account a speed of the preceding vehicle and inhibits a stop of the engine in the case where the preceding vehicle is in the acceleration phase. Advantageously, the device takes into account a speed of the preceding vehicle and inhibits a stop of the engine in the case where the preceding vehicle has a speed greater than the vehicle equipped with said device.

[001 1] Advantageously, the device takes into account a speed of the preceding vehicle and triggers a start of the engine in the case where the preceding vehicle passes from a stationary situation to a rolling situation.

Advantageously, the device triggers a start of the engine in the case where the preceding vehicle changes from a stationary situation to a rolling situation despite a detection of immobility of the vehicle equipped by the control device and despite detection of a action of the driver controlling the stopping of the engine of the vehicle.

Advantageously, the device takes into account a speed of the previous vehicle and it initiates a start of the engine in the case where the preceding vehicle accelerates.

Advantageously, the device takes into account a signal indicative of an action of the driver on a brake pedal of the vehicle equipped by the device as a condition for initiating a stopping of the engine.

Advantageously, the device takes into account a signal indicative of an action of the driver on a brake pedal of the vehicle equipped with the device and takes into account a signal of disappearance of the action of the driver on the brake pedal as a condition to initiate a motor start.

The invention also relates to a method for automatically controlling the starting and / or stopping of a combustion engine of a motor vehicle, comprising the steps of initiating a stop and / or starting of the engine taking into account at least one action of a driver of the vehicle so as to initiate the stopping and / or starting of the engine depending on the presence of this action of the driver, the method being characterized in that it comprises the step of also take into account a result delivered by a vehicle detector preceding the vehicle whose start and / or start of the engine is initiated so as to initiate the stopping and / or starting of the engine according to this result.

Other features, objects and advantages of the invention will appear on reading the description which follows, with reference to the appended figures in which:

FIG. 1 is a functional diagram corresponding to an automatic stop and start control device according to one embodiment of the invention;

- Figure 2 is a graph showing an evolution of different conditions affecting a stop and automatic start in this same embodiment. The stop and automatic start control device shown in Figure 1 comprises a control module 10 consisting of an onboard computer, and a series of condition detection devices to which the vehicle is subjected.

Thus, the present device comprises a sensor 20 on a brake pedal of the vehicle, a vehicle speedometer 30 and a detector 40 of presence of a vehicle preceding the vehicle equipped with the present device. This presence detector 40 of a vehicle is here a driving assistance system. This driver assistance system 40 also called collision avoidance system typically aims to automatically control a distance between the vehicle equipped by this system and the vehicle in front of it. For this purpose, the present driving assistance system delivers a certain amount of information such as a measure of the distance separating such a vehicle from the vehicle which precedes it, the time which separates these two vehicles, and the speed of the vehicle. vehicle preceding the equipped vehicle.

In the present embodiment, the information used primarily is the speed of the previous vehicle. With this information, here we will define the conditions relating to the speed of the preceding vehicle which must be respected to authorize the stopping of the engine as well as conditions relating to the speed of the preceding vehicle triggering an automatic restart of the engine by anticipation .

Indeed, it turns out that in an urban route, the speed of a vehicle is largely imposed by the vehicle ahead. The speed of the vehicle ahead is often a picture of the vehicle considered anticipated a few seconds.

By using the behavior of this vehicle, we can predict the will of the driver, and therefore limit the unwanted stops, or even restart the engine before the driver asks.

In the following, the vehicle equipped with the present stop control device and automatic start and here having a coupling of the stop control functions and automatic start and inter-vehicle distance control will be called "Vehicle STT >> and the vehicle before it will be called "Front Vehicle".

When no vehicle is present or visible in front of the vehicle STT, the conditions for stopping and restarting the engine remain unchanged here. In the case of an STT vehicle with automated gearbox, the engine is automatically stopped if the vehicle speed becomes less than 8 km / h and the driver presses the brake pedal. In the following, we will call this situation the "driver stop configuration". The engine is restarted if the vehicle speed becomes above 12 km / h or when the driver releases the brake pedal. In the following, these situations will be referred to as "driver restart configurations".

In the case where a vehicle precedes the vehicle equipped with the present device, and when the driver stopping configuration is present, the module 10 verifies the behavior of the front vehicle.

If the front vehicle decelerates and has a lower speed than the STT vehicle or if it is completely stopped, then the engine stop is allowed. This type of situation is encountered on arrival at a traffic light "red", at an intersection with a "give way" with priority vehicles on a perpendicular road, or at an intersection with a sign "stop >>. In these different cases, the engine downtime will be sufficiently long, and therefore profitable.

If the front vehicle re-accelerates or the front vehicle has a higher speed than the vehicle STT, then the module 10 prohibits the engine stop. This type of situation is encountered on arrival at a traffic light passing "green" at an intersection without priority vehicles on the perpendicular roadway or in line. In these latter cases, the engine stopping time would have been too short, and the engine stop would have embarrassed the driver.

In FIG. 2, the speed of the vehicle STT is represented by a track 100. The speed of the front vehicle is represented by a track 200. A speed threshold to authorize the stop is represented by a horizontal line 300. vertical line 400 corresponds to obtaining the driver stopping configuration. A vertical line 500 corresponds to obtaining the driver restart configuration. A vertical line 600 corresponds to a new obtaining of the driver stopping configuration. A vertical line 700 corresponds to a new obtaining of the driver restart configuration. Finally, two traces 800 and 900 represent signals which become active when the engine is stopped and inactive when the engine is in operation, these two lines 800 and 900 respectively corresponding to a control device according to the present embodiment and to a control device. control according to the prior art.

At moment 400, the speed of the vehicle STT represented by the track 100 passes below the speed threshold 300. The speed of the front vehicle, represented by the track 200, being lower and being decelerated, then the stop is allowed. The engine stopping time between points 400 and 500 is long enough to be profitable. At time 600, the speed 100 of the vehicle STT falls below the speed threshold 300. The speed 200 of the front vehicle is lower but is accelerating, so stopping is not authorised. As shown by the trace 900, without such a restart inhibition, the engine stopping time between 600 and 700 is too short to be profitable.

The module 10 is also programmed to trigger a restart from results provided by the driver assistance device 40 in the case where the vehicle is preceded by another vehicle. The speed information of the front vehicle is used here to supplement the driver restart configurations.

Indeed, if the two vehicles are stopped at a traffic light and the front vehicle starts to roll again, the module 10 anticipates restarting the engine of the vehicle STT before the driver releases the brake foot. The driver assistance device 40 emits a signal according to which the front vehicle starts rolling again or a signal formally constituting an engine restart command. The module 10 then interprets the restart information and initiates the engine restart. As a variant, the module 10 comprises a part of the driver assistance device, so that the interpretation of a restart of the front vehicle is carried out in the driver assistance device itself, a control of the driver assistance device. engine restart is then sent by the driver assistance device.

In another case, the vehicle equipped with the present system has a speed of less than eight km / h and the driver has his foot on the brake pedal, and this conductive stop configuration has triggered engine shutdown especially because that the speed of the front vehicle was low enough. In this situation, when the driver assistance device 40 indicates to the module 10 that the front vehicle is accelerating, the module 10 initiates an engine restart in anticipation that the driver will need to accelerate too.

In anticipation of the restart, the device allows the driver to no longer be bothered by a waiting time for the provision of engine torque, and the stop and start function becomes more transparent to the user.

We therefore complete the information used by the STT function, here brake support information and speed of the vehicle by information provided by a driver assistance system, and in particular by a control system of distance inter-vehicle, to better know the environment of the vehicle. Thus, a large number of undesired motor stops are suppressed, and the restart of the motor is anticipated in certain cases.

This embodiment has a significant technical interest directly visible by the driver of a vehicle STT. Indeed not only the unwanted motor stops are reduced in number, but we obtain a gain in consumption by the shorter stops are reduced and the driver's discomfort is reduced. By anticipating restarting the engine, we obtain a better transparency of the stop and start function for the driver, thanks to the fact that it eliminates a wait during departures following a motor shutdown.

These advantages will be even more noticeable on a vehicle having a stop and start device by starter, because the restart time is longer and it is difficult to restart an engine during shutdown, a situation that is particularly present when a short stop.

Claims

1. Automatic control device (10, 20, 30, 40) for starting and / or stopping a motor vehicle combustion engine, which device takes into account (10) at least one action of a driver of the vehicle (20) so as to initiate the stopping and / or starting of the motor as a function of the presence of this action of the driver, characterized in that the device also takes into account (10) a result delivered by a preceding vehicle detector (40) the vehicle equipped by the control device so as to initiate the stopping and / or starting of the engine according to this result.

2. Device according to claim 1, characterized in that it takes into account a speed (30) of the preceding vehicle to trigger a stop and / or start of the engine.

3. Device according to claim 1 or claim 2, characterized in that it takes into account a speed (200) of the preceding vehicle and inhibits stopping the engine in the case where the preceding vehicle is in the acceleration phase.

4. Device according to any one of the preceding claims, characterized in that it takes into account a speed (30, 200) of the preceding vehicle and inhibits a stopping of the engine in the case where the preceding vehicle has a speed (200) superior to the vehicle equipped with said device.

5. Device according to any one of the preceding claims, characterized in that it takes into account a speed (200) of the preceding vehicle and triggers a start of the engine in the case where the preceding vehicle passes from a stationary situation to a driving situation.

6. Device according to the preceding claim, characterized in that it triggers a start of the engine in the case where the preceding vehicle changes from a stationary situation to a rolling situation despite a detection of immobility of the vehicle equipped by the device of control (10,20,30,40) and despite detection of a driver action (40) controlling the stopping of the vehicle engine.

7. Device according to any one of the preceding claims, characterized in that it takes into account a speed of the preceding vehicle and it initiates a motor start in the case where the preceding vehicle accelerates.

8. Device according to any one of the preceding claims, characterized in that it takes into account a signal indicative of an action of the driver (20) on a brake pedal of the vehicle equipped by the device as a condition to initiate a stopping the engine.

9. Device according to any one of the preceding claims, characterized in that it takes into account a signal indicative of a driver action on a brake pedal (20) of the vehicle equipped with the device and takes into account a signal the disappearance of the action of the driver on the brake pedal (20) as a condition to initiate a starting of the engine.

10. A method for automatically starting and / or stopping a combustion engine of a motor vehicle, comprising the steps of initiating a stopping and / or starting of the engine taking into account at least one action (20) of a driver of the vehicle so as to initiate the stopping and / or starting of the engine according to the presence of this action (20) of the driver, the method being characterized in that it comprises the step of taking it also includes a result delivered by a vehicle detector (40) preceding the vehicle whose start and / or start of the engine is initiated so as to initiate the stopping and / or starting of the engine as a function of this result.