DE102012217899A1 - Method for automatic switching off and starting of engine in motor vehicle, involves detecting foot motion and foot position of rider by foot space monitoring unit, when shutdown and starting of engine in response to signal is affected - Google Patents

Abstract

The method involves switching off the drive motor at a speed (v) when the accelerator pedal (GP) is dissolved or dissolved. The drive motor is automatically restarted and switched-off, when the accelerator pedal is activated based on the positive drive torque. The foot motion and foot position of the rider is detected by a foot space monitoring unit, when automatic shutdown and starting of the engine in response to the signal of leg room monitoring unit is affected.

Description

The invention relates to a method for automatically switching off and starting an engine in a vehicle according to the preamble of patent claim 1.

Currently, internal combustion engines are usually switched off manually by means of an ignition key by the driver. An exception is a method which is described in the DE 100 23 331 A1 is presented. In this case, the brake pedal position or the brake pedal pressure is evaluated instead of the ignition key. The shutdown of the internal combustion engine is initiated when the brake pedal is more strongly actuated in its already actuated position after reaching the standstill of the motor vehicle. To continue driving the brake pedal is released and pressed the accelerator pedal, after which a start of the internal combustion engine is initiated. A disadvantage of such methods that alone the motor vehicle driver is responsible for switching off the internal combustion engine. Analyzes of today's driving behavior show that despite increased environmental awareness and increased fuel prices, a manual shutdown of the engine, z. B. at traffic lights, rarely independently.

In order to reduce fuel consumption and pollutant emissions, methods and systems are currently being developed and partly already in use, which automatically shut down the engine of a motor vehicle under certain conditions or in the presence of predetermined shutdown conditions at vehicle standstill and automatically turn on again in the presence of predetermined Anschaltbedingungen. 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.

Such a method is, for example, from the DE 10 2008 061 790 A1 known. In this case, the internal combustion engine is automatically switched off when the vehicle is decelerated to a standstill and held by operating the brake pedal at a standstill. Further, an automatic starting of the internal combustion engine when releasing the brake pedal can be prevented here, when the brake pedal is stepped amplified when the internal combustion engine is switched off. A re-start then takes place only when the accelerator pedal is actuated or when a timely operation of the accelerator pedal is detected by means of a footwell monitoring unit.

In order to be able to save even more fuel, systems are already known which activate a so-called sailing mode when the vehicle and the accelerator pedal are released, in which the engine is released from the drive train and thus the kinetic energy of the vehicle is used to roll as far as possible without the drag torque of the engine braking the vehicle. Such a method is, for example, from the DE 10 2008 029 453 A1 known. In addition, in the still unpublished DE 10 2011 082 893 A1 discloses that in sailing operation, the engine is completely turned off and is restarted only at a subsequent pulling phase. Thus, even more fuel economy can be achieved.

The object of the invention is therefore to provide a method in which on the one hand fuel can be saved by automatically switching off and off the engine while the vehicle is moving, but at the same time also ensures that the engine in situations where drive power is required, this also in operation is.

This object is achieved by a method according to claim 1. Advantageous developments are the subject matters of the dependent claims.

In the method according to the invention for automatically shutting off and starting an engine (which can be configured, for example, as an internal combustion engine) in a motor vehicle, an automatic shut-off process is already initiated at speeds greater than zero by means of a start-stop device when the accelerator pedal is released is and all other (system-side) shutdown conditions such. B. sufficient outside temperature and sufficient state of charge of the vehicle battery are present. In addition, as a minimum requirement for allowing an automatic shutdown of the prime mover, the non-actuation of the brake pedal can be specified, since to apply sufficient braking force, an electric brake booster is required in order to ensure a sufficient delay can.

Furthermore, the automatically switched-off prime mover will automatically start at the latest when the accelerator pedal is actuated in such a way that a positive drive torque is requested. Similarly, a restart can be initiated when a brake pedal operation is detected.

The basic idea of the invention is now to recognize and to take into account corresponding actions of the driver that influence the automatic switch-off or restart of the drive machine at an early stage. For this purpose, the invention provides that by means of a Footwell monitoring unit foot movement and / or foot position of the driver is detected, and that the automatic shutdown and / or starting the engine is influenced in response to a signal of Fußraumüberwachungseinheit. Thus, it can already be detected much earlier, whether the driver wants a speedy acceleration (by pressing the accelerator pedal) or deceleration (by pressing the brake pedal) or not. The footwell monitoring unit may be any system which detects a foot movement and / or foot position in the foot area of the driver. In the simplest way, it may be a proximity sensor in the region of the accelerator pedal and / or brake pedal, which emits a corresponding signal when the driver's foot enters or leaves the area of the accelerator pedal or brake pedal. Furthermore, infrared-based systems or camera systems are conceivable, by means of which not only the position of the driver's foot, but also the direction of movement and / or the speed with which the foot moves and / or the acceleration of the driver's foot can be determined.

Advantageously, the shutdown of the engine is influenced in response to the signal of the footwell monitoring unit such that a shutdown of the prime mover when releasing the accelerator pedal is prevented when a timely brake pedal operation is detected or suspected by the footwell monitoring unit. This makes sense, since due to the detection of a timely actuation of the brake pedal it can be assumed that a stronger deceleration of the vehicle is desired and thus the prime mover would have to be restarted within a very short time. Since only a very short shutdown of the prime mover for energy efficiency reasons does not make sense, it is better to prevent the automatic shutdown.

A timely brake pedal actuation can advantageously be detected or suspected by means of the footwell monitoring unit if a foot movement in the direction of the brake pedal is detected when the accelerator pedal is released. In addition, also the speed and / or acceleration of the foot can be determined and incorporated into the detection or suspicion of a timely brake pedal operation. If, for example, by means of the footwell sensor system when releasing the accelerator pedal a (fast) movement of the foot in the direction of the brake pedal is detected, it can be inferred that the driver wants to actuate the brake pedal in order to initiate a deceleration. However, if by means of the footwell sensor system when releasing the accelerator pedal it is recognized that the driver slowly takes the foot off the gas pedal and either holds it over the accelerator pedal or slowly moves it to the right, it can be assumed that the driver will drive as energy-efficiently as possible by exploiting the kinetic energy or want to sail and thus an automatic shutdown of the prime mover makes sense and should be allowed.

In addition to monitoring the foot movement and / or foot position, it also makes sense to monitor other parameters or operating conditions of the vehicle and to decide depending on whether an automatic shutdown of the prime mover makes sense. For example. For example, an automatic shutdown of the engine when the vehicle is moving can only be permitted if the speed of the vehicle is greater than a predetermined limit speed. This limit speed can turn fixed, or depending on other parameters, such. B. the currently traveled road type variable. An influence of the driver on the speed limit is also conceivable. For example. 25 km / h on local roads, 80 km / h on rural roads or 160 km / h on motorways can be specified as limit speeds. This is useful because z. B. yes after the type of road the sailing mode with the prime mover switched off can be used for a sufficiently long time only when certain speed thresholds are exceeded, so that a fuel saving can be achieved at all. Further, it is also conceivable to specify an upper limit speed, but an automatic shutdown of the prime mover is no longer allowed.

Advantageously, vehicle environment information can also be determined by means of an environmental monitoring system, which are then taken into account in the decision regarding the initiation of an automatic shutdown and / or states of the prime mover, ie the automatic shutdown and / or starting of the prime mover can depending on the information of the environment monitoring system to be influenced. By taking into account environmental information, it can be better estimated whether, for example, an automatic shutdown of the prime mover at the current time makes sense or not. In particular, the automatic shutdown and / or switching on of the engine can be influenced by the determined environment information such that a shutdown of the prime mover when releasing or with accelerator pedal is prevented when a timely acceleration of the vehicle is determined or suspected based on the information of the environmental monitoring system. If, for example, detected by means of the environmental monitoring system that the driver moves to a traffic light, which has just switched to red and due to the distance to the traffic lights a braking intervention seems necessary to come to a stop in front of the traffic light, it makes sense, the automatic Switching off the Drive machine to prevent, even if all other shutdown conditions are met. Likewise, the environment information can be taken into account such that a shutdown of the drive machine is allowed if no timely acceleration of the vehicle is determined or suspected based on the information of the environment monitoring system. This would be the case, for example, if it is detected that the road in front of the vehicle is free, and no speed limits have been determined or a reduction in speed due to traffic signs or driving instructions or other road users appears necessary.

Under certain operating conditions, the case may arise that, for example, an automatic shutdown of the drive machine would be permitted on the basis of the determined environment information, but a timely braking intervention is detected or suspected by means of the footwell monitoring unit. This conflict can advantageously be resolved by prioritizing the signal of the footwell monitoring unit or the measure derived therefrom (eg prevent shutdown, allow shutdown, enable required) than the information of the surroundings monitoring system or the measure derived therefrom. In particular, a prioritization of the data of the footwell monitoring system or the measure derived therefrom is useful if, due to the signal of the footwell monitoring unit, an automatic shutdown of the prime mover should be prevented. Alternatively, the conflict may be solved in the case of differently requested measures due to the two monitoring systems, that in terms of Abschaltstrategie in the presence of a so-called. Abschaltverhinderers the prime mover is never turned off and with respect to the Einschaltstrategie in the presence of a so-called Einschaltaufforderers the prime mover is always started automatically.

The evaluation of the data of the footwell monitoring unit can be done not only to influence the automatic shutdown of the prime mover, but also to influence the restart of the prime mover. In this case, in an advantageous embodiment of the invention, the automatic starting of the drive machine depending on the signal of Fußraumüberwachungseinheit be influenced such that the automatic start of the drive machine already takes place when detected by the footwell monitoring unit timely accelerator pedal operation or brake pedal operation or suspected. Thus, the drive torque can be provided much earlier.

In the drawing, an embodiment of the invention is shown. The single FIGURE shows a simplified flowchart for the inventive method.

The procedure begins in step 10 in which it is queried whether all required driver-side and system-side conditions (eg sufficient state of charge of the battery) which are necessary for an automatic shutdown of the internal combustion engine at speeds greater than zero (that is, while the vehicle is traveling) are met. In particular, it is queried whether the current speed v of the vehicle is greater than a predetermined limit speed vG of z. B. 25 km / h and whether the gas pedal GP is released.

If this is the case, the next step is 20 by evaluating the detected by an environment monitoring system UÜS signals s determined whether there is a traffic situation or environment information has been determined that prevent an automatic shutdown of the internal combustion engine (MSA stop). If so, the prime mover remains operational due to the determined shutdown inhibitor and the process is complete.

However, if an automatic stop is always permitted by appropriate evaluation of the signals s of the environmental monitoring system UUS, in the next step 30 the signals s of a Fußraumüberwachungssytems FRÜ arranged in the footwell of the driver evaluated to see whether on the basis of the determined foot movement of the driver a timely actuation of the brake pedal BP is to be expected. This can be done, for example, by evaluating the direction of movement of the foot during or after the release of the accelerator pedal.

If a timely brake pedal actuation is detected, an automatic stop (MSA stop) is prevented in analogy to above by setting a so-called. Abschaltverhinderers, so no automatic shutdown of the engine initiated. The procedure then ends.

However, if no timely brake pedal operation is detected, it goes to step 40 passed over and initiated an automatic stop (MSA stop) of the internal combustion engine. Then it becomes step 50 passed, in which it waits until a so-called Einschaltaufforderer is detected. A Einschaltaufforderer is, for example, then recognized or set when the accelerator pedal GP is pressed or even when an accelerator operation based on the data of the footwell monitoring system is suspected. Once a power-on requestor is detected, the next step is 60 the internal combustion engine started again (MSA start).

By the method proposed here can be ensured in a simple manner that the drive machine is automatically stopped when the vehicle is running only if it is to be assumed that this is desired by the driver and that the initiated automatic stop the prime mover for energy efficiency reasons makes sense. Furthermore, it can be ensured that the drive power is available again early after a stop phase of the drive machine.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10023331 A1 [0002]
• DE 102008061790 A1 [0004]
• DE 102008029453 A1 [0005]
• DE 102011082893 A1 [0005]

Claims (7)

Method for automatically switching off and starting a prime mover in a motor vehicle, in particular in a motor vehicle with automatic transmission, by means of a start-stop device which automatically shuts off the prime mover at speeds (v) greater than zero when the accelerator pedal (GP) is released or released is, and which automatically starts the engine off automatically at the latest when the accelerator pedal (GP) is actuated in such a way that a positive drive torque is requested, characterized in that by means of a footwell monitoring unit (FRÜ) foot movement and / or foot position of the driver can be detected, and the automatic shutdown and / or starting of the drive machine in response to a signal of the footwell monitoring unit (s (FRÜ)) is influenced. A method according to claim 1, characterized in that the shutdown of the drive machine in response to the signal of Fußraumüberwachungseinheit (s (FRÜ)) is influenced such that a shutdown of the engine when releasing the accelerator pedal (GP) or when the accelerator pedal (GP) is prevented if a timely brake pedal actuation is detected or suspected by means of the footwell monitoring unit (FRÜ). A method according to claim 2, characterized in that a timely brake pedal operation is detected or suspected when a foot movement in the direction of the brake pedal is detected when releasing the accelerator pedal (GP). Method according to one of the preceding claims, characterized in that the engine at speeds (v) greater than zero and releasing the accelerator pedal (GP) or accelerator pedal (GP) is only automatically switched off when the speed (v) greater than a predetermined limit speed (vG) is. Method according to one of the preceding claims, characterized in that by means of an environment monitoring system (UÜS) vehicle environment information can be determined and the automatic shutdown and / or starting of the engine depending on the information of the environment monitoring system (s (UÜS)) is influenced, in particular such a shutdown of the engine when releasing the accelerator pedal (GP) or with accelerator pedal (GP) is prevented when a timely acceleration of the vehicle based on the information of the environment monitoring system (s (UÜS)) is determined or suspected and / or that switching off the Engine is approved if no timely acceleration of the vehicle based on the information of the environmental monitoring system (s (UÜS)) is detected or suspected. Method according to one of the preceding claims, characterized in that the signal of the footwell monitoring unit (s (FRÜ)) or the influence derived therefrom for automatically switching off or starting the engine is prioritized higher than the information of the environment monitoring system (s (UÜS)), in particular when an automatic shutdown of the prime mover is prevented due to the signal of the footwell monitoring unit (s (FRÜ)). Method according to one of the preceding claims, characterized in that the automatic starting of the drive machine in response to the signal of Fußraumüberwachungseinheit (s (FRÜ)) is influenced such that the automatic start of the drive machine already takes place when using the footwell monitoring unit (FRÜ) a timely accelerator operation is detected or suspected.

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