DE102007063944B3 - Method for controlling an automatic switch-off operation and / or switch-on operation of an internal combustion engine in a motor vehicle - Google Patents

Abstract

A method for controlling an automatic shutdown and / or startup of an internal combustion engine in a motor vehicle by means of a start-stop device, by which after starting the internal combustion engine by a person and driving the motor vehicle when stopping the motor vehicle, the internal combustion engine is automatically switched off, if predetermined Shutdown conditions are met by appropriate influencing factors, and / or by which automatically switched off internal combustion engine is turned on, if predetermined startup conditions are met by corresponding factors, characterized in that for an evaluation of shutdown and / or Anschaltbedingungen an activity state of an electric parking brake is taken into account in that a turn-on condition for automatically switching on the internal combustion engine consists in that automatic switching on of the internal combustion engine is only possible is when, when detected active electric parking brake, the accelerator pedal has gone so far that the accelerator pedal position deviates from its base by more than a predetermined accelerator pedal position threshold.

Description

The invention relates to a method for controlling an automatic switch-off operation and / or an automatic switch-on operation of an internal combustion engine in a motor vehicle according to the preamble of claim 1.

In order to reduce fuel consumption and pollutant emissions, methods and systems are currently being developed and partly already in use, which automatically switch off the internal combustion engine of a motor vehicle under certain conditions or in the presence of predetermined switch-off conditions and automatically switch it on again in the presence of predetermined switch-on conditions. Such methods and systems or start-stop devices are particularly suitable for city traffic to reduce fuel consumption, since in city traffic, the vehicle often stops at traffic lights or traffic and the operation of the internal combustion engine is not required.

So is out of the DE 101 61 343 A1 an automatic stop and start control device for an internal combustion engine is known, wherein the control device performs appropriate measures for switching off the internal combustion engine when all said shutdown conditions are met. For example, the speed of the vehicle must be below a predetermined limit, with manual transmissions may be no gear engaged and in automatic transmission vehicles, the gearshift position of the transmission must be in neutral position.

Next discloses the DE 100 30 290 A1 also a method and system for automatically shutting down and restarting an internal combustion engine. In this case, an automatic shutdown is prevented when the state of charge of the battery of the vehicle is below a predetermined blocking threshold. As a further shutdown conditions are still checked whether the speed of the vehicle is below a predetermined limit, whether the transmission is idling and whether the accelerator pedal is in rest position.

• - die Motorhaube muss geschlossen sein,
• - das Geschwindigkeit des Kraftfahrzeugs ist kleiner als eine vorgegebene Geschwindigkeitsschwelle oder gleich Null,
• - das Gaspedal ist nicht betätigt,
• - das Bremselement ist betätigt,
• - mindestens die Fahrertür ist geschlossen,
• - im Falle eines Automatikgetriebes steht der Wählhebel auf einer Fahrstellung,
• - die Temperatur der Abgasanlage hat ihren Betriebswert erreicht,
• - der Verbrennungsmotor hat seine Betriebstemperatur erreicht,
• - das Getriebe bzw. das Getriebeöl hat Betriebstemperatur erreicht und die Druckversorgung und damit die Schaltbarkeit des Getriebes sowie die Vermeidung einer Überhitzung im Getriebe ist auch bei ausgeschaltetem Motor sichergestellt,
• - von der Klimasteuerung einer Klimatisiereinrichtung liegt eine Freigabe vor
• - es liegt eine Freigabe durch eine Batterie- Kontrolleinrichtung vor,
• - eine gegebenenfalls vorgesehene Verzögerungszeit vor dem Aktivieren des automatischen Abschaltvorgangs ist abgelaufen und
• - ein Ein-Aus-Schalter zum manuellen Einschalten und Ausschalten der Start-Stopp-Einrichtung ist im Einschaltzustand.

From the DE 102 11 461 C1 is a method for automatically switching off and on an internal combustion engine known in which a variety of factors in the evaluation of shutdown conditions and / or Anschaltbedingungen are taken into account. Thus, an automatic shutdown of the internal combustion engine is possible if the following shutdown conditions are met simultaneously:

• - the bonnet must be closed,
• the speed of the motor vehicle is less than a predetermined speed threshold or equal to zero,
• - the accelerator pedal is not activated,
• - the brake element is actuated,
• - at least the driver's door is closed,
• in the case of an automatic transmission, the selector lever is in a driving position,
• - the temperature of the exhaust system has reached its operating value,
• - the internal combustion engine has reached its operating temperature,
• - The transmission or the transmission oil has reached operating temperature and the pressure supply and thus the switchability of the transmission and the prevention of overheating in the transmission is ensured even when the engine is switched off,
• - From the climate control of an air conditioning device is available
• there is a release by a battery control device,
• - an optionally provided delay time before activating the automatic switch-off process has expired and
• - An on-off switch for manually switching on and off the start-stop device is in the on state.

From the DE 103 12 390 A1 is a is a method for automatically switching off and on an internal combustion engine is known, which is provided that the internal combustion engine is automatically turned off upon actuation of a parking brake of the vehicle.

In addition to these already known shutdown conditions, however, other factors must be taken into account so that such a start-stop device is accepted by the driver and no implausible states occur.

The object of the invention is therefore to provide an improved method for controlling an automatic shutdown and / or power-on of an internal combustion engine by means of a start-stop device.

This object is achieved by a method according to claim 1. Advantageous developments emerge from the dependent claims.

The basic idea of the invention is that, in addition to the known parameters influencing the control of an automatic switch-off and / or switch-on operation by means of a start-stop device, a large number of further influencing variables have to be taken into consideration so that a start-stop device for automatic shutdown offered to the customer is provided and turning on the engine finds maximum acceptance and no implausible system or vehicle conditions occur.

According to the invention, an activity state of an electric parking brake should be considered in addition to or as an alternative to the known influencing variables for an evaluation of switch-off conditions and / or switch-on conditions.

According to the invention, a start-up condition for automatically switching on the internal combustion engine is only possible if the accelerator pedal has traveled so far when the active electric parking brake is detected that the accelerator pedal position deviates from its base by more than a predetermined accelerator pedal position threshold value.

The inclusion of this influencing variable in the evaluation of a switch-off condition and / or switch-on condition is therefore important, since otherwise the function of the electric parking brake would be meaningless if the internal combustion engine were already started if the electric parking brake could still intervene.

1. a) das Vorhandensein bzw. Nichtvorhandensein eines Fahreridentifikationsgebers und/oder eines Fahrzeugschlüssels, der ggf. als Funkfahrzeugschlüssel ausgestaltet sein kann,
2. b) der Zustand, in dem sich ein im Fahrzeug vorhandenes Tankentlüftungssystem, vorzugsweise ein Aktivkohlefilter befindet,
3. c) der aktuelle Tankfüllstand eines Kraftstofftanks,
4. d) der Zustand, in dem sich ein im Fahrzeug vorhandener Dieselpartikelfilter befindet,
5. e) ein Aktivitätszustand eines Werkstatt- und/oder Werk- und/oder Service- und/oder Fertigungsmodus,
6. f) die aktuelle Umgebungstemperatur außerhalb des Fahrzeugs,
7. g) eine Auswertung einer Fahrersitzbelegungs- und ggf. einer Beifahrersitzbelegungserkennungseinrichtung, wobei die Sitzbelegungserkennungseinrichtung in Form einer Sitzbelegungsmatte und/oder eines Kamerasystems und/oder eines Gurtschloss-Auswertungssystems ausgestattet ist,
8. h) das Erkennen einer Zylindergleichstellung,
9. i) ein Aktivitätszustand eines Fahrgeschwindigkeitsregelsystems,
10. j) ein Aktivitätszustand einer sog. Autohold-Funktion bei Kraftfahrzeugen mit Automatikgetrieben, und/oder
11. k) ein Aktivitätszustand einer sog. Hillhold-Funktion.

Advantageously, in addition to this influencing variable, at least one of the following influencing variables should be considered in the evaluation of switch-off conditions and / or switch-on conditions:

1. a) the presence or absence of a driver identification transmitter and / or a vehicle key, which may possibly be designed as a radio key,
2. b) the state in which there is a tank ventilation system present in the vehicle, preferably an activated carbon filter,
3. c) the current tank level of a fuel tank,
4. d) the condition in which a diesel particulate filter is present in the vehicle,
5. e) an activity state of a workshop and / or factory and / or service and / or production mode,
6. f) the current ambient temperature outside the vehicle,
7. g) an evaluation of a driver seat occupancy and possibly a passenger seat occupancy recognition device, wherein the seat occupancy recognition device is provided in the form of a seat occupancy mat and / or a camera system and / or a buckle evaluation system,
8. h) recognizing a cylinder equalization,
9. i) an activity state of a cruise control system,
10. j) an activity state of a so-called. Autohold function in motor vehicles with automatic transmissions, and / or
11. k) an activity state of a so-called hillhold function.

Advantageously, the influencing variable described under a) is evaluated such that an automatic switching off and / or switching on of the internal combustion engine is prevented if no valid driver identification transmitter and / or vehicle key is recognized. The switch-off condition and / or switch-on condition thus consists in that an automatic switch-off and / or switch-on process can only be carried out if a valid driver identification transmitter and / or vehicle key is recognized. A valid driver identification transmitter and / or driver key is present if the driver identification transmitter is detected in such a way that switching on the internal combustion engine would be possible again. This would not be the case, for example, if the driver identification transmitter, which does not necessarily have to be at a certain point in the vehicle, would fall out of the window during the journey, for example, or would be defective and thus could not send a valid signal to the vehicle. For example, no vehicle key could be detected if the plug-in device in which the vehicle key has to be inserted at least when starting the internal combustion engine is so defective that it does not recognize the inserted vehicle key or the vehicle key is not inserted in the intended insertion device.

The inclusion of this factor in the evaluation of a shutdown condition is therefore important because although driving without a key under certain conditions may be possible, but not turning on the engine. An automatically switched off internal combustion engine would then not be able to be switched on - it would come to a so-called. This would thus lead to a considerable lack of comfort of the start-stop device in the driver.

In an advantageous embodiment of the invention, the start-stop device can also be completely disabled if after the initially recognized benign driver identification transmitter and / or driver key later no valid driver identification transmitter and / or vehicle key is detected more.

Advantageously, the influencing variable described under b) is evaluated such that an automatic shutdown of the internal combustion engine is prevented when a tank ventilation system present in the vehicle is in the saturation region. If the tank ventilation system is an activated carbon filter, an automatic shutdown and / or switching on of the internal combustion engine must be prevented if the loading of the activated carbon filter is greater than a predetermined loading limit value. The switch-off condition and / or switch-on condition therefore consists in that an automatic switch-off and / or switch-on process can only be carried out if the loading of the activated carbon filter is less than the predefined loading limit value (including hysteresis etc.).

The inclusion of this factor in the evaluation of a shutdown condition is important because otherwise it could come through the automatic shutdown of the engine to a breakthrough of the activated carbon filter and thus the activated carbon filter could be ineffective in its operation. This could unintentionally increase the escape of pollutants or odor nuisance in the passenger compartment.

Advantageously, the influencing variable described under c) is evaluated such that an automatic shutdown of the internal combustion engine is prevented if the tank level of a fuel tank or a mean or maximum or minimum value of several tank levels is less than a predetermined tank level limit. This shutdown condition is thus that an automatic shutdown can only be performed if the tank level of the fuel tank is greater than the predetermined tank level limit.

The inclusion of this factor in the evaluation of a shutdown condition is therefore important because in an automatically switched-off internal combustion engine and a very low tank level switching on the engine u. U. would not be possible. An automatically switched off internal combustion engine would then not be able to be turned on and thus lead to a significant lack of comfort in the driver. Advantageously, the tank level limit can be variable, for example. Depending on the current inclination of the motor vehicle can be specified. This is useful because at an inclination of the motor vehicle, the intake u. U. sucked into the void and a suction of fuel is no longer possible.

Advantageously, the influencing variable described under d) is evaluated such that an automatic shutdown of the internal combustion engine is prevented when a diesel particulate filter present in the vehicle is in a regeneration phase. This shutdown condition is thus that an automatic shutdown can only be performed if the diesel particulate filter is not in a regeneration phase.

The inclusion of this factor in the evaluation of a shutdown condition is important because otherwise it could come through the automatic shutdown and / or turning on the engine to damage the diesel particulate filter or the diesel particulate filter could be ineffective in its operation. This could increase the emission of pollutants.

Advantageously, the influencing variable described under e) is evaluated in such a way that an automatic switching off and / or switching on of the internal combustion engine is prevented when a workshop and / or factory and / or service and / or manufacturing mode is actively switched in the motor vehicle. This switch-off condition therefore consists in that an automatic switch-off process and / or switch-on process can only be carried out if no active workshop and / or factory and / or service and / or production mode is detected.

The inclusion of this factor in the evaluation of a shutdown condition is important because such a mode is usually active only when the motor vehicle is not fully functional. If an automatic switch-on and / or switch-off process were nevertheless to be carried out, this could lead to (further) damage to a system in the motor vehicle, jeopardize employees, plant or service personnel or prolong production times.

In an advantageous embodiment of the invention, the start-stop device can be completely deactivated when it is detected that a workshop and / or factory and / or service and / or manufacturing mode is active. As a result, plant, service and production processes can be accelerated or made safer.

Advantageously, the influencing variable described under f) is evaluated such that an automatic shutdown and / or switching on of the internal combustion engine is prevented when the ambient temperature is not within a predetermined temperature window. This switch-off condition thus consists in that an automatic switch-off process and / or switch-on process can only be carried out if the current ambient temperature outside the motor vehicle is greater than a predetermined lower temperature limit and at the same time less than a predetermined upper temperature limit.

The inclusion of this factor in the evaluation of a shutdown condition is important because otherwise it could lead to an unexpected or implausible shutdown and / or Anschaltverhalten the internal combustion engine or damage to various vehicle systems.

Advantageously, the lower temperature limit value can be identical to a temperature limit value which is already interrogated in the vehicle and, if it is undershot, a warning signal is output anyway.

Advantageously, the influencing variable described under g) is evaluated in such a way that an automatic switching off and / or switching on of the internal combustion engine is prevented if the evaluation of a driver seat occupancy recognition device and possibly a passenger seat occupancy recognition does not reveal a seat occupancy. This switch-off condition therefore consists in that an automatic switch-off process and / or switch-on process can only be carried out if the evaluation of the driver seat occupancy recognition device shows that the driver seat is occupied by one person.

A seat occupancy can be detected with different systems or combinations of systems. A seat occupancy can be detected for example by means of a seat occupancy mat and / or with a camera system. Additionally or alternatively, the condition of a buckle can be evaluated. In addition, it can also be determined whether the driver's door and / or the passenger's door is open or closed. The front passenger door can play a role, for example, if the driver can not leave the vehicle on the driver's side because of lack of space, but only via the passenger door.

The inclusion of this influence, that is the evaluation of the seat occupancy recognition device in the form of a seat occupancy mat and / or an interior camera and / or a buckle evaluation unit in the evaluation of a shutdown condition is therefore important because an automatic shutdown and / or startup without the presence of a driver could lead to a hazard - for example, when the engine is restarted when the driver has left the vehicle in the meantime.

Advantageously, the influencing variable described under h) is evaluated such that an automatic shutdown of the internal combustion engine is prevented when a cylinder equalization is detected. This switch-off condition thus consists in that an automatic switch-off process can only be carried out if there is no cylinder equalization or recognition.

The inclusion of this factor in the evaluation of a shutdown condition is important because otherwise it may happen that the shutdown is performed at the moment of the cylinder equalization adaptation. In this case, a stop occurs with significant loss of comfort and a worse starting position for the next automatic start (start comfort loss).

Advantageously, the influencing variable described under i) is evaluated in such a way that an automatic switching off and / or switching on of the internal combustion engine is prevented if at the same time a speed control system, preferably a combined distance and speed control system is active. The switch-off condition and / or switch-on condition thus consists in that an automatic switch-off and / or switch-on process can only be carried out if no active vehicle speed control is detected.

The inclusion of this factor in the evaluation of a shutdown condition is therefore important because the motor vehicle u in speed control operation. U. could reach a speed that is detected as a standstill, and the engine is then turned off accidentally. This could, for example, be the case if suddenly a steep gradient is to be negotiated at a slow regulating speed. The speed of the vehicle could then near zero in the short term due to a limited torque reserve and a regulation delay.

Advantageously, the influencing variable described under j) is evaluated in such a way that an automatic switching on of the internal combustion engine is prevented if the brake pedal is released in the case of an active so-called "auto hold function" as long as the accelerator pedal has not been stepped on. The turn-on condition is thus that an automatic turn-on in a motor vehicle with automatic transmission and active "Autohold function is performed only when the accelerator pedal has gone so far that the accelerator pedal position deviates from its basic position by more than a predetermined accelerator position threshold.

The inclusion of this variable in the evaluation of a start-up condition is important because otherwise the engine would always be started if the so-called. Autohold function could still intervene (on condition that a conventional start-up condition in motor vehicles with automatic transmissions is the release of a brake ). The autohold function could not be used in conjunction with the auto-start-stop function.

Advantageously, in a motor vehicle with an automatic transmission, a connection condition for automatically switching on the internal combustion engine in a motor vehicle is that an automatic switching on of the internal combustion engine is only possible if no auto hold function is active when releasing the brake.

According to the influencing variable described above and under j), the influencing variable described under k) is advantageously evaluated in such a way that an automatic switching on of the internal combustion engine is prevented if the gas pedal is not stepped on in the case of an active and so-called hillhold function present in the vehicle. The turn-on condition is thus that an automatic turn-on in a motor vehicle Hillhold function is performed only when the accelerator pedal is stepped down with active hillhold function that the accelerator pedal position deviates from its home position by more than a predetermined accelerator position threshold. An alternative embodiment of the turn-on condition is that an automatic turn-on in a motor vehicle with a so-called. Hillhold function can only be performed when the hillhold function is not active.

The inclusion of this influencing variable in the evaluation of an activation condition is therefore important, since otherwise the so-called hillhold function would become meaningless if the internal combustion engine were already started if the so-called hillhold function could still intervene.

By evaluating these factors mentioned in the context of shutdown conditions and / or startup conditions, the system executing the automatic shutdown and startup operations becomes much more transparent and leads to less implausible vehicle states. In addition, the interaction with other driving control systems is resolved.

Claims (6)

A method for controlling an automatic shutdown and / or startup of an internal combustion engine in a motor vehicle by means of a start-stop device, by which after starting the internal combustion engine by a person and driving the motor vehicle when stopping the motor vehicle, the internal combustion engine is automatically switched off, if predetermined Shutdown conditions are met by appropriate influencing factors, and / or by which automatically switched off internal combustion engine is turned on, if predetermined startup conditions are met by corresponding factors, characterized in that for an evaluation of shutdown and / or Anschaltbedingungen an activity state of an electric parking brake is taken into account in that a turn-on condition for automatically switching on the internal combustion engine consists in that automatic switching on of the internal combustion engine is only possible is when, when detected active electric parking brake, the accelerator pedal has gone so far that the accelerator pedal position deviates from its base by more than a predetermined accelerator pedal position threshold. Method according to Claim 1 , characterized in that for an evaluation of shutdown conditions and / or Anschaltbedingungen at least one of the following factors for an evaluation of shutdown conditions and / or Anschaltbedingungen is considered: a) the presence of a driver identification transmitter and / or a vehicle key, b) the state in c) the current tank level of a fuel tank, d) the state in which a diesel particulate filter is present in the vehicle, e) an activity state of a workshop and / or factory and / or or service and / or production mode, f) the current ambient temperature outside the vehicle, g) an evaluation of a driver seat occupancy recognition device, the seat occupancy recognition device in the form of a seat occupancy mat and / or a camera system and / or a buckle evaluation system h) the recognition of a cylinder equalization, i) an activity state of a vehicle speed control system, j) an activity state of a so-called auto hold function in motor vehicles with automatic transmissions, and / or k) an activity state of a hillhold function. Method according to Claim 2 , characterized in that a turn-on condition for automatically switching on the internal combustion engine is that an automatic starting of the internal combustion engine is only possible if the accelerator pedal is so far when detected active Autohold function that the accelerator pedal position from its base by more than a predetermined Gaspedalstellungsschwellwert deviates. Method according to Claim 2 , characterized in that a start-up condition for automatically switching on the internal combustion engine in a motor vehicle with automatic transmissions is that an automatic turning on of the internal combustion engine is only possible if when releasing the brake no auto-hold function is active. Method according to one of Claims 2 - 4 , characterized in that a further turn-on condition for automatically switching on the internal combustion engine is that an automatic turning on of the internal combustion engine is only possible if no active hillhold function is detected. Method according to one of Claims 2 - 4 , characterized in that a further turn-on condition for automatically switching on the internal combustion engine is that an automatic starting of the internal combustion engine is only possible if the accelerator pedal is so far when detected active Hillhold function that the accelerator pedal position from its base by more than one predefined accelerator pedal position threshold deviates.