DE102015003557A1 - Method for adjusting the distance of a vehicle - Google Patents

Abstract

The invention relates to a method for controlling the distance (16) of a drive train and a drive train coupled to the drive train and decoupled from the drive train having vehicle, in which at least the longitudinal dynamics of the vehicle is automatically influenced by a computing device, wherein if by means of a sensor device (26). the vehicle is determined that the vehicle is approaching a preceding vehicle, by means of the computing device at least one simulation is performed, based on which for normal operation, in which the drive unit is coupled to the drive train, and for a sailing operation, in which the drive unit from Powertrain is decoupled, each a time at which the speed of the vehicle of the speed of the vehicle ahead is expected to comply, and one at the time between the vehicles expected herrs be determined distance, wherein the vehicle is automatically operated by means of the computing device depending on the respective determined distance in sail mode or normal operation.

Description

The invention relates to a method for controlling the distance of a vehicle according to the preamble of patent claim 1.

Such methods for controlling the distance of a vehicle are already well known from the general state of the art. In this case, the vehicle comprises a driver assistance system, which is usually designed as a distance control. Such a cruise control is a cruise control system, which includes the distance to a preceding vehicle in the regulation of the speed. This means that in the method for distance control, at least the longitudinal dynamics of the vehicle is automatically influenced by means of a computing device. The computing device of the vehicle is usually referred to as a control unit and thus serves for distance control. By influencing the longitudinal dynamics is to be understood that by means of the computing device, the acceleration and deceleration or a driving and braking torque of the vehicle influenced, in particular adjusted and, for example, regulated, for example, to avoid in the context of distance control, that the distance between the Vehicle and the preceding vehicle further falls below a predetermined threshold.

In this case, the vehicle comprises a drive train and a drive unit which can be coupled to the drive train and can be decoupled from the drive train and which is designed to drive the vehicle. The drive unit is, for example, an internal combustion engine which can be coupled to the drive train, for example by means of a clutch. If the clutch is closed, then the drive unit is coupled to the drive train, so that the vehicle or the wheels of the vehicle can be driven by the drive unit or delayed by means of the drive unit, for example in the context of engine braking. If the clutch is open, the drive unit is disconnected from the drive train, so that the wheels of the vehicle can not be driven by means of the drive unit.

From the DE 10 2009 040 682 A1 a method for speed control of a vehicle is known in which a plurality of alternative strategies, so-called control variants, a suitable strategy is selected, which is to be based on the cruise control. The selection of the strategy to be used is dependent on route parameters, which include, for example, slope data. Furthermore, the selection of the strategy to be used is based on vehicle parameters, wherein the suitability of the speed control strategy is checked based on a simulation of the course of the speed.

Furthermore, the DE 10 2008 038 078 A1 a method for predictive speed control of a vehicle is known in which the speed control can take place according to several strategies. A first of the strategies involves rolling the vehicle with the powertrain closed. This means that, for example, a gear is engaged and the drive unit is in overrun mode. A second of the strategies involves rolling out the vehicle with the powertrain open. Here, no gear is engaged, so that the drive unit is idling. The strategy to be used is determined as a function of a forward-looking route profile.

In the conventional method for distance control, the drive unit is usually always coupled to the drive train, so that the longitudinal dynamics of the vehicle can be influenced by means of the computing device on the drive unit and the drive train.

Object of the present invention is therefore to develop a method of the type mentioned in such a way that the energy consumption of the vehicle during the activated distance control can be kept particularly low.

This object is achieved by a method having the features of claim 1. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

In order to develop a method specified in the preamble of claim 1 type such that the energy consumption, in particular the fuel consumption of the vehicle during the distance control can be kept particularly low, it is inventively provided that, if determined by means of a sensor device of the vehicle, that When the vehicle approaches a further vehicle in front, at least one simulation is carried out by means of the computing device. Based on the simulation for a normal operation, in which the drive unit is coupled to the drive train, and for a sailing operation, in which the drive unit is decoupled from the drive train, each time a time at which the speed of the vehicle of the speed of the vehicle ahead is likely to correspond , and one at a time between each Vehicles expected ruling distance determined. Furthermore, the vehicle is automatically operated by means of the computing device as a function of the respective determined distance in sailing or normal operation.

The normal operation and the sailing operation are respective strategies or operating strategies according to which the vehicle can be operated. In normal operation, the drive unit is coupled to the drive train, so that the longitudinal dynamics of the vehicle can be influenced by means of the drive unit via the drive train. In normal operation, for example, a clutch is closed, so that the drive unit is coupled via the clutch to the drive train. In normal operation, therefore, the vehicle can be driven by means of the drive unit, in particular accelerated, or, for example, in the context of engine braking, that is, for example, in overrun operation of the drive unit, delayed or decelerated. In sailing operation, the drive unit is disconnected from the drive train, so that the longitudinal dynamics of the vehicle can not be influenced by the drive unit in sail operation. In normal operation, the drive unit is coupled to drivable or driven wheels of the vehicle, wherein the drive unit is decoupled from the wheels in the sailing mode. Furthermore, it is preferably provided that the drive unit, which is designed, for example, as an internal combustion engine, is deactivated in the sail mode in order to keep the fuel consumption of the drive unit as a whole particularly low.

In cases or situations in which the vehicle is approaching a preceding and especially slower further vehicle when the distance control is activated or activated, it is to be decided in the context of the method according to the invention whether and, if appropriate, which of the two aforementioned strategies is to be used. The influencing of the longitudinal dynamics of the vehicle caused by the computing device is also referred to as longitudinal regulation, since accelerations and decelerations in the vehicle longitudinal direction are automatically effected by the computing device or because the speed of the vehicle is adjusted, in particular regulated, at least in the vehicle longitudinal direction.

In the context of the method, it is thus decided in accordance with which of the strategies the vehicle is operated, while the longitudinal control is performed by the computing device. For this purpose, a simulation is carried out for both strategies, for example, in order to predict for the respective strategy a point in time, that is to say to predict, when the vehicle is likely to have adjusted its speed to the speed of the preceding vehicle. Furthermore, the respective distance is determined on the basis of the respective simulation, which is expected to arise between the two vehicles at this time. If, for example, the distance determined for one of the two strategies satisfies a predetermined boundary condition or a specifiable criterion or a predefinable condition, it is decided that the respective strategy belonging to the distance satisfying the condition should be used.

The boundary condition is met, for example, when the predicted distance corresponds to a predetermined desired distance, possibly plus or minus a predetermined tolerance range. In particular, it can be provided that the respective distance is defined as a metric distance or as a time limit, ie time interval.

Background of the invention is that distance controller or adaptive cruise control as an output variable continuously affect the acceleration and deceleration or the driving and braking torque of the vehicle. The drive train should remain closed so that the distance controller remains in the pass. By this is meant that the drive unit is coupled to the drive train. Conventionally, a condition to open the drive train, that is to uncouple the drive unit from the drive train, not so easy to find, since there is always a small error, which makes a caused by the computing intervention in the longitudinal dynamics of the vehicle required. As a result, there is almost always an obstacle to sailing in controlled operation, that is to say when the distance control is activated.

By means of the method according to the invention, however, it is now possible to sail when the distance control is activated, so that the energy consumption, in particular the fuel consumption, of the vehicle, which is designed, for example, as a motor vehicle, in particular as a passenger car, can be kept particularly low.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or alone in the single figure are not only in the respectively indicated combination but also in others Combinations or alone, without departing from the scope of the invention.

The drawing shows in the only Fig. A block diagram illustrating a method for the distance control of a vehicle.

The single FIGURE shows a block diagram illustrating a method for the distance control of a vehicle, which is designed as a motor vehicle, especially passenger cars. The vehicle comprises a drive train and a drive unit, for example in the form of an internal combustion engine, wherein the drive unit can be coupled to the drive train and decoupled from the drive train. For this purpose, for example, a starting element is provided in particular in the form of a coupling, wherein the drive unit can be coupled by means of the coupling with the drive train. If the clutch is closed, then the drive unit is coupled to the drive train, and the vehicle can be driven by means of the drive unit, that is, in particular accelerated, or delayed, for example, in the context of engine braking. If the clutch is open, the drive unit is decoupled from the drive train, and the vehicle, in particular wheels of the vehicle, are not drivable by the drive unit.

From the Fig. Is an operating element in the form of an accelerator pedal 10 recognizable of the vehicle, the accelerator pedal 10 Also referred to as accelerator. The driver of the vehicle can use the accelerator pedal 10 over his foot 12 actuate. The driver moves with his foot 12 the accelerator pedal 10 from its rest position in one of them different operating position, so the driver requests a drive torque from the internal combustion engine, wherein the vehicle is driven by the drive torque when the clutch is closed. The accelerator pedal 10 is thus an operating element for influencing the longitudinal dynamics of the vehicle. The vehicle further comprises an operating element 14 , by means of which the driver with the 16 can activate and deactivate designated distance control. Within the scope of the distance control, that is to say when the distance control is activated, at least the longitudinal dynamics of the vehicle are automatically influenced by means of a computing device of the vehicle. Activates the driver via the control element 14 the distance control 16 so is the distance control 16 activated only as long as the driver the accelerator pedal 10 not activated. The vehicle further comprises, for example, a notification system, which is designed as the haptic accelerator pedal accelerator pedal 10 includes.

Further, the vehicle is operable in a normal operation and in a sail operation. In normal operation, the drive unit is coupled to the drive train. In sailing operation, the drive unit is decoupled from the drive train and thus from the wheels of the vehicle. Preferably, it is further provided that the drive unit is deactivated in sail mode.

The driver drives himself and unregulated, that is, the driver presses the accelerator pedal 10 and is the automatic distance control 16 disabled, so one with 18 designated manual drive control is activated, the driver is by means of the hint system on the haptic accelerator pedal 10 Haptic informs that the driver sensibly from the accelerator pedal 10 go, that is the accelerator pedal 10 let go, thereby rolling out the vehicle. As a result, energy or fuel can be saved.

It is also possible, the hint system or the haptic accelerator pedal 10 to use to make the driver, for a certain time completely from the gas or accelerator pedal 10 to go, so with activated distance control 16 the drive unit disconnected, that is disengaged and the vehicle can be operated in sail mode, while the distance control 16 is activated. In other words, one can use the operating principle of the notification system, the distance control 16 or to take the distance controller from the control loop, that is, the so-called loop.

For example, the driver switches over the control element 14 the distance control 16 and thus changes from the manual drive train control 18 with corresponding functions and parameters 20 in a controlled mode by the longitudinal dynamics of the vehicle is automatically influenced by the computing device. This mode is the distance control 16 ,

The distance control 16 includes a distance controller 22 , Will now be by means of a sensor device 26 If the vehicle determines that the vehicle is approaching a vehicle in front, then by means of the computing device at least one simulation is made 24 carried out. This means that the simulation 24 for example, parallel to the classic distance controller 22 is calculated by the computing device.

Based on the simulation 24 For example, for normal operation and for sailing operation, a time point at which the speed of the vehicle is expected to correspond to the speed of the preceding vehicle ahead is determined, and in each case a prevailing distance between the vehicles at the time. Furthermore, the vehicle by means of Computing device depending on the respective determined distance automatically operated in sail mode or normal operation. If the vehicle is in normal operation with distance control activated 16 operated, so the vehicle with a closed drive train, that is roll out coupled with the drive train drive unit. On the other hand, if the vehicle is operated in sail mode, the vehicle can roll out with the drive train open, that is to say with the drive unit uncoupled from the drive train. Normal operation and sailing operation are thus borderline cases or strategies from which a strategy is selected. If it is determined by means of the simulation that the strategy "coasting with open drive train" can be selected, the drive unit is decoupled from the drive train and deactivated, for example, so that the fuel consumption of the vehicle can be kept particularly low while simultaneously performing the distance control 16 ,

In a fixed cycle, the then valid start values become the simulation 24 started when a relevant moving object as the preceding vehicle by means of the sensor device 26 is recognized. Here, a prognosis is made of when and where the vehicle will reach the speed of the preceding object and how far the preceding object will move. This data can be used to decide whether roll-out is the right operating strategy and whether it is rolled out with the powertrain open or closed. Accordingly, the torque request or the like is fixed to the value zero and on with 28 designated, determined coasting mode is started. The simulation 24 is thus a pre-simulation or pre-simulation in which, in addition to the data of the moving objects, information about the preceding gradient and curve profile can optionally also be used. In other words, it is conceivable by means of the simulation 24 determine the distance and the time as a function of data which characterize a preceding section of the route, which the vehicle will be driven on in the future. These data, which are also referred to as route data, characterize, for example, inclines, slopes and / or curves of the route section.

The simulation 24 will continue to be cycled. This can lead to a switchover from the disengaged state, that is, from the sailing operation, to the engaged state, that is, to normal operation, when the pre-simulation comes to a different result in the course of the real situation. This can be triggered, for example, if the preceding vehicle further reduces its speed in the course of coasting. Likewise, there may be a switch from engaged to disengaged when the preceding vehicle becomes faster.

• – die Geschwindigkeit des vorausfahrenden weiteren Fahrzeugs wird erreicht oder um einen definierten Wert unterschritten;
• – der Zeitabstand im eingekuppelten Zustand zum vorausfahrenden Fahrzeug unterschreitet eine definierte Schwelle;
• – das vorausfahrende Fahrzeug wird nicht mehr von der Sensoreinrichtung 26 erfasst;
• – der Fahrer gibt Gas, das heißt betätigt das Fahrpedal 10, so dass die Abstandsregelung 16 passiv geschaltet beziehungsweise deaktiviert wird;
• – der Fahrer schaltet durch Bremsen oder über das Bedienelement 14 die Abstandsregelung 16 ab.

The coasting mode 28 will be terminated as soon as one of the following criteria is met:

• - The speed of the preceding vehicle is reached or exceeded by a defined value;
• - The time interval in the engaged state to the vehicle in front falls below a defined threshold;
• - The vehicle ahead is no longer from the sensor device 26 detected;
• - The driver accelerates, that is, presses the accelerator pedal 10 so the distance control 16 is switched passive or deactivated;
• - The driver switches by braking or via the operating element 14 the distance control 16 from.

With the completion of the Ausrollsituation is the classic distance control 16 activated.

In the simulation 24 Thus, it is a forward-looking simulation, by means of which a forward-looking roles in distance-controlled driving is feasible. By predictive simulation and the activation of the sail operation in relevant situations, the distance-controlled ride can be optimized in terms of energy consumption.

Both with regulated travel, that is with activated distance control 16 , as well as uncontrolled driving, that is, with the distance control disabled 16 , can the driver by means of the haptic accelerator pedal 10 be notified that the driver should go from the gas to the coasting mode 28 to enable or allow a roll out. Since the same Ausrollhinweis both in the regulated drive and in the unregulated drive goes to the driver, there is another advantage, because the vehicle behaves the same in the regulated as unregulated ride. Overall, it is thus possible to realize a forward-looking roles in distance-controlled driving, thereby keeping the energy and fuel consumption of the vehicle particularly low.

The sensor device 26 is a so-called environmental sensor system, which comprises at least one environmental sensor, preferably a plurality of environmental sensors. By means of the sensor device 26 Thus, it is possible to detect at least a part of the environment of the vehicle and thus to detect objects in the vicinity of the vehicle.

LIST OF REFERENCE NUMBERS

10

accelerator

12

foot

14

operating element

16

distance control

18

manual drive train control

20

Functions and parameters

22

Adaptive Cruise Control

24

simulation

26

sensor device

28

Ausrollmodus

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 102009040682 A1 [0004]
• DE 102008038078 A1 [0005]

Claims (5)

Method for distance control ( 16 ) of a drive train and a drive train coupled to the drive train and decoupled from the drive train having vehicle in which at least the longitudinal dynamics of the vehicle by means of a computing device is automatically affected, characterized in that if by means of a sensor device ( 26 ) of the vehicle is determined that the vehicle is approaching a preceding vehicle, by means of the computing device at least one simulation is performed, based on which for normal operation, in which the drive unit is coupled to the drive train, and for a sail operation, in which the drive unit is decoupled from the drive train, in each case a time at which the speed of the vehicle presumably corresponds to the speed of the vehicle in front, and in each case a prevailing prevailing distance between the vehicles is determined, the vehicle being operated by the computer in dependence on the respective vehicle determined distance is automatically operated in sail mode or normal operation. A method according to claim 1, characterized in that the distance is determined as a distance, in particular metric distance, or as a time interval. A method according to claim 1 or 2, characterized in that when at least one of the distances satisfies a predetermined condition, the vehicle is operated in belonging to the condition-fulfilling distance belonging operation. A method according to claim 3, characterized in that the at least one distance satisfies the condition when the at least one distance corresponds to a predetermined desired distance or lies in a predefinable value range. Method according to one of the preceding claims, characterized in that by means of the computing device is switched from sailing operation to normal operation, when - the speed of the vehicle corresponds to the speed of the vehicle ahead or the speed of the vehicle, the speed of the preceding vehicle further by a predetermined value below; and / or - the distance, in particular time interval, of the vehicle to the further vehicle in normal operation falls below a predefinable threshold value; and / or - the further vehicle by means of the sensor device ( 26 ) is no longer recorded; and / or - the driver has at least one operating element ( 10 ) operated to influence the longitudinal dynamics of the vehicle; and / or - the driver deactivates the automatic influencing of the longitudinal dynamics to be effected by the computing device.

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