WO2009092481A1

WO2009092481A1 - Method and device for automatically switching on and off an internal combustion engine

Info

Publication number: WO2009092481A1
Application number: PCT/EP2008/066322
Authority: WO
Inventors: Joerg Zeller; Florian Kloss
Original assignee: Robert Bosch Gmbh
Priority date: 2008-01-25
Filing date: 2008-11-27
Publication date: 2009-07-30
Also published as: DE102008006028A1

Abstract

The invention relates to a method and device for automatically starting or switching off an internal combustion engine of a motor vehicle, wherein at least the following steps are performed: detecting (S1) environmental data, evaluating (S2) the environmental data for identifying a particular traffic situation, changing (S4) the operating mode of the internal combustion engine by starting or switching off when the particular traffic situation is identified (S3). Optical information or light signals from the vehicle surroundings are detected by a sensor as environmental data. The sensor for detecting environmental data is part of a parking aid sensor or a camera system.

Description

description

title

Method and device for automatically switching on and off an internal combustion engine

Technical area

The invention relates to a method and a device for automatically switching on and off an internal combustion engine, in particular an internal combustion engine of a motor vehicle. The invention can be adapted in all conventional motor vehicles as a comfort function.

State of the art

Against the background of rising energy and fuel costs as well as increasing environmental awareness of broad consumer groups, efforts to reduce fuel consumption and pollutant emissions from motor vehicles are an essential part of development work in the field of automotive technologies. In addition to the continuous improvement of the efficiency and the efficiency of the internal combustion engines used, efforts are made to limit their running time during the operation of the relevant motor vehicle to the absolutely necessary level. This can be done by combining them with other drive concepts, as is the case with hybrid vehicles. However, even without the possibility of switching to alternative drive types, the running time of the internal combustion engine can be shortened if it is switched off in phases in which no drive of the motor vehicle is required, if permissible. There are known devices that automate such shutdown and thus make largely independent of the driver's request. These devices, which are to be subsumed under an automatic start-stop system, evaluate different control elements of the motor vehicle whose position and / or operating state allow conclusions to be drawn about the operating state of the motor vehicle and the possible existence of a traffic situation that may make it advisable to switch off the internal combustion engine. If such a traffic situation is assumed, there is an automatic shutdown of the engine.

It is known to evaluate the position of the shift lever and clutch pedal to initiate an automatic shutdown of the engine. If the driver puts the gearshift lever in the neutral position and takes his foot off the clutch, the engine electronics switch off the engine. When the clutch pedal is actuated again, the engine is started without further intervention by the driver, and the vehicle is ready to engage the gear for starting.

It is known to evaluate the position of the brake pedal in motor vehicles with automatic transmission at standstill of the vehicle and otherwise proceed analogously to realize an automatic shutdown of the engine.

A disadvantage of such systems, however, is that the mere evaluation of in-vehicle conditions, such as those derived by the position of the monitored controls, a clear identification of traffic situations that would justify a shutdown of the engine can not be done with sufficient certainty. Not in every case, in which a motor vehicle comes to a standstill, a shutdown of the engine is useful when no gear is engaged and the corresponding switching operation is not yet initiated. The frequency of such conditions depends to a great extent on the driving habits of the respective driver. In order to prevent too frequent and / or too short interim shutdown of the engine, such automatic shutdown usually work with a predetermined delay of the order of a few seconds. It is therefore assumed that after stand a traffic situation without need for drive over a certain minimum period, this situation with sufficient likelihood will continue to make the then already delayed automatic shutdown of the engine still appear appropriate.

The statistical nature of such steering decisions is a weakness of such systems. With authorized shutdown of the engine, this takes place relatively late, which reduces the desired savings effect. In the case of misinterpretations of the traffic situations, despite the envisaged delay, a very fast start-up can be achieved with a relatively high degree of probability, which may even lead to additional start-up and emission increases, which would in any case be counterproductive.

Disclosure of the invention

An idea of the invention aims to identify the shutdown of internal combustion engines justifying operating situations by evaluating environmental information and to realize an automated activation or deactivation. In the case of motor vehicles, such environmental information often provides a secure means of identifying different traffic situations.

A method is provided for automatically starting or shutting down an internal combustion engine of a motor vehicle, comprising at least the following steps:

a collection of environmental data,

an evaluation of the environment data for identifying a specific traffic situation, and an automatically initiated change of the operating state of the internal combustion engine by starting or stopping when the specific traffic situation is identified. The change of the operating state of the engine in the context of the invention is always appropriate or there is a certain When the vehicle is running and the vehicle is stationary, a long-term standstill of the vehicle is to be expected or when the vehicle is stationary with the engine switched off, an early start is to be expected.

A minimum configuration suitable for carrying out the method according to the invention consists in a device integrated in a motor vehicle for automatically starting or shutting down the internal combustion engine of this motor vehicle, comprising at least one sensor for acquiring environmental data, at least one data processing unit for evaluating the acquired environmental data and identifying the existing traffic situation and at least a control unit that is designed to make a change of the operating state of the internal combustion engine by starting or stopping when a traffic situation is identified in which this change is expedient.

The acquisition of the environmental data can be cyclic, continuous or event-driven. As environment data for use within the method according to the invention, in principle automatically detectable data are suitable, which allow an assignment to certain traffic situations and can be used for their identification. The identification of the traffic situation can advantageously be done in combination with other identification methods in order to achieve a particularly high identification security.

Advantageous effects

The essential advantage of the procedure according to the invention is that in many cases no delay is required to increase the statistical security in order to identify the traffic situation in question. The decision about the change of the operating state of the internal combustion engine can generally be made immediately after the evaluation of the environmental data indicating the traffic situation in question. As a result, unnecessary engine runtime is saved compared to conventional start-stop systems, which reduces the fuel consumption and pollutant emissions of such a vehicle equipped.

It has proved to be advantageous if distance data are recorded as environmental data. These may relate to distances to fixed obstacles in the vehicle environment or distances to other vehicles.

Such distance data are often available as output data of a parking aid sensor system integrated in motor vehicles. From such distance data can be derived in an advantageous manner, whether the stoppage of a motor vehicle as a result of approaching an obstacle or preceding vehicle takes place or just a vehicle-specific required holding situation, for example, a short-term existing Vorfahrtssituation arose.

It has proven to be similarly advantageous if optical information about the vehicle environment is detected as ambient data. In a particularly advantageous manner, light signals can be detected as such ambient data. This can be done by camera systems integrated in motor vehicles and / or corresponding optical sensors, which are preferably designed for color recognition. The identification of a traffic light located in the vicinity of the relevant motor vehicle, the display status and preferably the switching times allows in many cases a largely error-free identification of the existing traffic situation and a sufficiently accurate prediction arising subsequent situations that a change of the operating state of the internal combustion engine, for example in the form of its shutdown before a red light until the next start of the motor vehicle, the maximum achievable savings effect, since it can be made virtually instantaneous.

A further advantage of the invention is that the sensors required for acquiring the environmental data are already integrated in many vehicles for realizing other functions. This applies in particular to different Stand sensors for parking aids, in vehicles for high demands but also for various camera systems, which are also partly provided to facilitate parking and / or the realization of other Konnfortfunktionen, such as so-called ACC systems (automatic cruise control) are used. Since the engine control and associated with the startup or shutdown of the engine almost exclusively takes place via electronic circuits, in most cases providing a designed for the realization of the method according to the invention software to retrofit a vehicle for the use of the functionality shown with respect the automated connection or disconnection of the engine.

Brief description of the drawings

In one embodiment, the invention will be explained below. Show it:

1 shows an excerpt from a generalized program flow chart of the method according to the invention;

2 shows an exemplary program flowchart of the invention

process; and

Fig. 3 is a schematic representation of the components of a device for carrying out the method.

Embodiments of the invention

1 shows an excerpt from a generalized program flowchart of the method according to the invention, which illustrates the steps required to execute the method. In a first step S1, the detection of environmental data from the environment of the motor vehicle takes place. This environmental data is evaluated electronically in step S2 in such a way that the traffic situation associated with this environmental data is identified as precisely as possible. The identification of the traffic situation in a step S3 can either confirm a traffic situation that matches the existing operating state of the internal combustion engine or indicate a changed traffic situation in which a change of the operating state of the internal combustion engine is expedient. If the latter traffic situation is identified, an automatic change of the operating state of the internal combustion engine takes place by starting or stopping in a next step S4. This minimum sequence of program steps can be supplemented and / or superimposed by further measures for changing the operating state of the internal combustion engine, for example safety-related and / or manually effected shut-off processes.

2 shows an exemplary program flowchart of the method according to the invention. Shown is an automated shutdown. According to this embodiment, there is a constant query of the front sensors of a parking aid sensor. This query corresponds to the detection of environmental data from the environment of the motor vehicle in the sense of the present invention. After appropriate evaluation, the output signals of the sensors either provide the information that there is no obstacle within such an observable area, or provide data about the distance between the obstacle and the motor vehicle in the presence of an obstacle in the area in question (step S5). The evaluation of the distance data thus obtained also makes it possible to track the evolution of this distance. If the distance is shortened to a typical distance for consecutive vehicles and the vehicle is then at a standstill, this indicates with a higher probability the existence of a traffic situation in which the shutdown of the engine may be useful than that in the mere identification of the vehicle standstill the case would be. Typical situations of this course are the driving up and stopping at the end of the jam, the stopping behind vehicles, which are at a traffic light or the parking of the vehicle behind an obstacle. In all these cases, it is to be assumed that a minimum residence time, which requires the shutdown of the engine for reasons of economy. An advantageous embodiment of the method is therefore that the engine is automatically switched off when the distance to an obstacle does not change, the value this distance is below a threshold value S and the vehicle is at a standstill (steps S5, S6 and S7).

In order to largely rule out that the obstacle being controlled is a preceding vehicle that stops even for a moment, as may be the case when crossing intersections, for example, in addition to the distance data an integrated camera system captures optical information about the vehicle environment. This includes pattern and color recognition algorithms that capture light signals and optical switching in color-resolved fashion.

If, for example, a traffic light is detected in connection with the approach to an obstacle or a vehicle ahead and the subsequently occurred vehicle standstill, which blocks the flow of traffic, a minimum residence time must be assumed, which is already conditioned by the prescribed switching cycle of the traffic light. It should also be assumed that the vehicle in front will not park in this position as this is likely to be inadmissible in most cases. Similarly, for example, an identified hazard warning system is to be interpreted which, in connection with the corresponding approach and a vehicle standstill following this approach, will in many cases indicate the achievement of a jam end or a dangerous situation requiring a stop and also a minimum dwell time in the sense of the one shown Procedure expected. In general, it can be assumed that it is advantageous if the engine is switched off, if a minimum residence time of the vehicle can be derived from optical information and the vehicle is at a standstill. The two procedures for identifying the traffic situation can also be used individually or alternatively.

In a stop position in the immediate vicinity of a traffic light, the next identifiable switching operation of the traffic light can be used to cause an automatic start of the engine. In a holding position at a greater distance to a halt causing traffic lights, it may be advantageous if the Automatic starting of the engine takes place when, after the vehicle has stopped, a further increase in the distance to the vehicle ahead is detected. Both the detected switching operation of the traffic light and the beginning of a change in distance are evaluated as indicia of the presence of a traffic situation in which a change of the operating state of the internal combustion engine by starting is appropriate. In this way, a sufficient lead time when starting the engine can be realized, which allows a familiar start immediately after engaging the gear.

Fig. 3 shows a schematic representation of the components of an apparatus for performing the method according to the invention. The device comprises distance sensors 2 of a parking aid sensor system and a camera system 5 for detecting the vehicle surroundings. Both forms sensors for acquiring environmental data in the sense of the invention. The output signals of the distance sensors 2 and of the camera system 5 are fed to a data processing unit 3 for evaluation of the acquired environmental data. The data processing unit 3 includes pattern and color recognition algorithms which can detect, for example, color signals in a color-resolved manner for light signals and optical switching processes. With the aid of the evaluated data, the most accurate possible identification of the existing traffic situation takes place, wherein misinterpretations due to the combination of distance and optical information can be largely excluded. The evaluation of the data also includes an examination of the expediency of a change of the operating state of the internal combustion engine 1 by starting or stopping in the respectively identified traffic situation.

Furthermore, a control unit 4 is included, which is designed to make a change of the operating state of the internal combustion engine 1 by starting or stopping. The control unit 4 can be created as part of an engine control unit. In addition, the control unit 4 ensures that a change of the operating state of the engine only takes place if operating elements relevant to the vehicle operation are in an operating position which is permissible for the upcoming change. For example, this can not be done automatically when a gear is engaged without the clutch has entered. The control unit 4 is also designed so that at any time a manual shutdown or starting the engine is possible or the function of the automated shutdown and / or starting can be switched off completely or partially.

To carry out the method according to the invention, it is irrelevant whether the components shown are designed as separate hardware components or are merely adapted to the illustrated functionality by a program-technical modification of existing assemblies.

Claims

claims

A method for automatically starting or shutting down an internal combustion engine of a motor vehicle, comprising at least the following steps: detecting environmental data (S1),

Evaluating (S2) the environmental data for identifying a specific traffic situation,

- Change (S4) of the operating state of the internal combustion engine by starting or stopping when the specific traffic situation is identified (S3).

2. The method according to claim 1, characterized in that distance data are detected as environmental data.

3. The method according to claim 1 or 2, characterized in that as environmental data optical information from the vehicle environment are detected.

4. The method according to any one of claims 1 to 3, characterized in that as ambient data light signals are detected.

5. The method according to any one of claims 1 to 4, characterized in that the engine is switched off when the distance to an obstacle does not change, the value of this distance is below a threshold value (S) and the vehicle is at a standstill.

6. The method according to any one of claims 1 to 5, characterized in that the engine is switched off (S8), if a minimum residence time of the motor vehicle can be derived from optical information and the vehicle is at a standstill.

7. The method according to any one of claims 1 to 4, characterized in that the engine is started when the vehicle is at a standstill and the distance to an obstacle begins to change and / or the possibility of further travel of the motor vehicle can be derived from optical information.

8. A device for automatically starting or shutting down an internal combustion engine (1) of a motor vehicle, comprising at least one sensor (2) for acquiring environmental data, at least one data processing unit (3) for evaluating the acquired environmental data in order to identify a specific existing traffic situation, and at least one control unit (4) which is designed to make a change of the operating state of the internal combustion engine by starting or stopping when the specific traffic situation is identified.

9. The device according to claim 8, characterized in that the at least one sensor (2) for detecting environmental data is part of a park assist sensor system.

10. Apparatus according to claim 8 or 9, characterized in that at least one sensor for detecting environmental data is part of a camera system (5) for detecting the vehicle environment.

A computer program which, when executed on a data processing unit, performs the method of any one of claims 1 to 7.