DE102015008239A1 - Method and device for controlling a creep torque of a vehicle - Google Patents

Abstract

The invention relates to a method for controlling or regulating a creeping torque of a vehicle. In one method, the creep torque is reduced as a function of at least one environmental information of the vehicle (1), preferably during a parking process.

Description

The invention relates to a method for controlling a creep torque of a vehicle, as well as to a vehicle having a device for controlling a creeping torque of a vehicle.

From the DE 199 49 204 A1 a motor vehicle with a coupling device is known, which has a creep torque limiting device. The creep torque limiting device reduces the clutch and the running vehicle, but not actuated brake and not actuated accelerator pedal, applied low torque between the engine and the transmission.

Such as creeping torque and with engaged gear in the stationary area technically conditioned propulsion torque allows the driver to drive slowly without pressing the accelerator pedal. The gentle propulsion makes it easier for the driver to park or roll the vehicle in heavy traffic. This creep function can be emulated by means of software functions in the vehicle. In parking situations in particular, the parking automatic installed in the vehicle, which must be activated by the driver, is not used, in particular during subsequent traffic or hectic situations. In conjunction with a creep function, it can thus happen that the vehicle slowly crawls against an obstacle and collides with it.

The object of the invention is to provide a method for controlling or regulating a creeping torque of a vehicle, in which a collision with an obstacle is avoided.

The invention results from the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

Other features, applications and advantages of the invention will become apparent from the following description, as well as the explanation of embodiments of the invention, which are illustrated in the figures. The object is achieved with a method in that the creep torque is reduced as a function of at least one environmental information of the vehicle, preferably during a parking operation. This avoids a collision with a standing or moving obstacle. In the case of a parking sensor system of the vehicle used in conjunction with the ambient function, the ambient sensor system present in the vehicle is used simultaneously for determining the obstacles in reducing the creeping torque, so that additional sensors can be dispensed with in the proposed method, which reduces the costs of the method.

Advantageously, obstacles are determined with the help of the environmental information of the vehicle in a driving path to be traversed with the creep torque. Since the direction of the vehicle is known, so can the obstacles, which are in the direction of travel of the vehicle, simply sense. This allows a distinction as to which obstacles must be considered in the reduction of the creep torque and which not.

In one embodiment, the reduction of the creep torque is determined as a function of a speed of the vehicle and a distance of the vehicle to the obstacle. This controls the creep torque to prevent collisions with obstacles. Thus, for example, unlocking on vehicles ahead in congestion situations, such as in a stop-and-go operation of the vehicle, is easily possible without colliding with them.

In one variant, the crawling torque is reduced by control technology in the event of an imminent collision of the vehicle with the obstacle, as detected by the surroundings information, so that the vehicle comes to a stop in front of the obstacle.

In one embodiment, the reduction of the creep torque is dependent on an actual distance of the vehicle to the obstacle and a desired distance of the vehicle to the detected obstacle. Since both the actual distance between the vehicle and the obstacle and a desired distance are determined by the ambient sensor system present in the vehicle, by which such a distance is to be understood, in which the vehicle still reliably stops standing without colliding with the obstacle is brought, a highly accurate adjustment of the creeping torque can be ensured.

In another embodiment, the desired distance is determined in dependence on whether the detected obstacle is moving or standing, wherein the desired distance to a moving obstacle is set greater than the desired distance to a stationary obstacle. This adjusts the creep torque to the current traffic.

In an alternative, the target distance to the obstacle is set to be greater when a gradient to be negotiated by the vehicle occurs than when driving through a plane. This ensures that, for example, to be overcome behind sustained vehicles slope due invisible starting situations of the vehicle in front the distance is set larger, in order to avoid a risk of collision.

A development of the invention relates to a vehicle having a device for controlling or regulating a creep torque of a vehicle, having an electric drive and / or an automatic clutch comprising a double clutch operation, wherein the device for controlling or regulating a creeping torque comprises a creeping torque. Limitation unit. In a vehicle in which the creep torque is controlled to avoid collision with obstacles, the device is designed as a control unit which is connected to the electric motor, wherein the control unit is connected to at least one sensor for detecting obstacles in the surroundings of the vehicle, which is guided to a distance calculation unit contained in the control unit for determining an actual distance and a desired distance of the vehicle to the obstacle detected in the environment, wherein the distance calculation unit is coupled to the creep torque limiting unit for reducing the creep torque. By means of such a vehicle, the creep torque can reliably be reduced so far in dependence on obstacles located in the environment of the vehicle and in the direction of travel of the vehicle that a collision with these obstacles is prevented. By reducing the creeping torque, the disadvantage is prevented that the creep torque is always active, which can lead to a collision with an obstacle in the driver's inattention.

In one embodiment, the creep torque limiting unit comprises a map for determining the creep torque as a function of a vehicle speed and a difference distance determined from the desired distance and the actual distance. Due to this characteristic field, it is possible to set the creep function independently of a defined scenario or of defined parking situations in such a way that a collision with an obstacle is avoided.

Advantageously, the at least one sensor for detecting the obstacle in the surroundings of the vehicle is part of a parking assistance system. By using environmental sensor systems that are present in the vehicle, the costs for the method are reduced.

Further advantages, features and details will become apparent from the following description in which - where appropriate, with reference to the drawings - at least one embodiment is described in detail. Described and / or illustrated features may form the subject of the invention itself or in any meaningful combination, optionally also independent of the claims, and in particular may also be the subject of one or more separate application / s. The same, similar and / or functionally identical parts are provided with the same reference numerals.

Show it:

1 an embodiment of the vehicle according to the invention,

2 a schematic diagram of the control unit according to 1 .

3 a representation of the dependence between creep torque and speed of the vehicle,

4 a schematic representation of the dependence of the creep torque on the distance to the obstacle and the speed of the vehicle.

In 1 is a vehicle according to the invention 1 shown, which is a control unit 3 having that with an electric motor 9 is coupled. To the control unit 3 Several environmental sensors are connected. These environmental sensors include at least one ultrasonic sensor 11 , a radar sensor 13 , a proximity sensor 15 , a tilt sensor 17 as well as a camera 19 ,

As in 2 shown, provide the ultrasonic sensor 11 , the radar sensor 13 , the proximity sensor 15 and the camera 19 Signals to one in the control unit 3 contained distance calculation unit 21 , by which a target and an actual distance of the vehicle 1 to at least one of the sensors 11 . 13 . 15 . 19 detected obstacle 23 that is in a driveway of the vehicle 1 is present, the distance calculation unit is determined 21 may be included in a parking system controller, a radar system controller, or other controllers that evaluate environmental information. However, it can alternatively also be contained in a control unit which is connected to an internal combustion engine 5 connected via a gearbox 7 connected to the electric motor.

As an output signal of the distance calculation unit 21 become the target distance 25 and the actual distance 27 , certainly. Below the target distance 25 should be considered below the distance that the vehicle 1 can cover a maximum without hitting the obstacle 23 to collide.

The distance calculation unit 21 With the aid of the sensor signals, it is possible to clearly determine whether the detected obstacle 23 is fixed or moving. When detecting stationary obstacles 23 , such as a garage wall, a fence or a tree, becomes a relatively small target distance 25 set. That is, the creeping moment is relatively close, based on the stationary obstacle 23 , in the way control technology reduces that the vehicle 1 comes to a stop in front of the obstacle. With moving obstacles 23 , such as a preceding or sustained vehicle, a larger target distance is set because the driver of the preceding vehicle has a very small target distance 25 could feel uncomfortable. This has the consequence that the creep torque is already reduced, if there is still a clear distance between the two vehicles. The actual distance 27 and target distance 25 become one in the controller 3 contained creep torque limiting unit 29 supplied in which a map for determining a creep M as a function of a distance of the vehicle 1 to the obstacle 23 and the speed v of the vehicle 1 is determined. The speed v of the vehicle 1 is from a speed sensor 31 detected, whose output signal to the control unit 3 is forwarded. The creep torque M determined from the characteristic field is output 33 of the control unit 3 the internal combustion engine 5 fed. This creep M is called the drive torque of the internal combustion engine 5 about a not shown in the transmission 7 included coupling to the electric motor 9 forwarded, which via a line 35 with the creep torque limiting unit 29 is connected, which the determined creep with the actual on the electric motor 9 adjusts adjacent creeping torque.

In 3 the dependence of the creep torque M on the vehicle speed v is shown. It can be seen that the creep torque M indirectly depends on the vehicle speed v. The larger the creep torque M, the smaller the speed v of the vehicle 1 ,

That in the creep torque limiting unit 29 stored map for the dependence of the creep torque M on the speed v of the vehicle 1 and the distance to the obstacle 23 is in 4 shown closer. It is assumed in area A that the actual distance 27 of the vehicle 1 to the obstacle 23 is greater than that of the distance calculation unit 29 calculated target distance 25 so that the vehicle 1 can continue to move with a reduced creep M. The creep torque M is determined by the creep torque limiting unit 29 control technology reduced when the target distance 25 reached at point T. This will ensure that the vehicle 1 not with the obstacle 23 collided. Is the vehicle located 1 but still in an area A to the obstacle 23 , so are due to the different distances with which the vehicle 1 the obstacle 23 approaching, constantly finding new creep M1, M2, M3, taking in the approach to the obstacle 23 the creep torque M is constantly reduced. If the creep torque M reaches zero, then it can be assumed that the target distance 25 of the vehicle 1 to the obstacle 23 was achieved and the vehicle 1 near the obstacle 23 has come to a standstill. This described reduction of the creeping torque M can be combined particularly well with a parking automatic of the vehicle, ie when the driver wants to maneuver his vehicle in a garage or drive into an underground car park with several columns and undefined parking spaces, since he does not have to make sure that himself the vehicle 1 do not crawl against obstacles.

This automatic parking allows the vehicle 1 to automatically park. In this case, the driver activates the parking operation after a suitable query of the parking area. This steering, gas and brake depending on the environmental sensors described by the 11 . 13 . 15 . 17 . 19 certain environmental information is controlled so that the vehicle 1 is maneuvered into the parking position to be determined. If the driver fails to activate the parking functions and the vehicle continues to move with a creep function that is always active, signals from the environmental sensors will be in this state 11 . 1 13 . 15 . 17 . 19 used to obstacles 23 , capture. The signals of these environmental sensors 11 . 13 . 15 . 17 . 19 are sent to the distance calculation unit 21 transmitted, which in the manner described, the actual and the desired distance of the vehicle 1 to the obstacle 23 to transfer. The creep torque limiting unit 29 reduces the creep torque even when the automatic parking system is switched off, causing a collision of the vehicle 1 with the obstacle 23 can be avoided in the track.

The influence of environmental information on the creep function can be switched off if required. This can be done in particular via a menu or by switching off the parking sensors. Likewise, a deactivation of the creeping torque can take place, whereby the driver drives the vehicle 1 continue with the accelerator pedal 37 can move in a certain direction. In this situation, the vehicle becomes 1 not independent against obstacles 23 drive.

The distance determination unit 21 can clearly determine whether the detected obstacle 23 is fixed or moving. Thus, the creep torque M is reliably set by a variable distance. When capturing standing obstacles 23 , such as a garage wall, a fence or a tree, becomes a relatively small target distance 25 set. That is, the creep M is only relatively close relative to the stationary obstacle 23 , fixed against zero, leaving the vehicle 1 comes to a standstill. With moving obstacles 23 , such as a preceding or sustained vehicle, becomes a larger target distance 25 set because the driver of the vehicle in front could feel a very small distance as unpleasant. This has the consequence that the creep M is already regulated, if there is still a clear distance between the two vehicles.

With the help of the tilt sensor 17 slope information will also be considered when reducing the creep torque M. For example, the target distance 25 be set to a persistent on a large slope vehicle due to unsafe Anfahrsituationen the preceding vehicle, relatively large to prevent a collision of the two vehicles. It is used to distinguish whether it is the detected obstacle 23 is a moving or stationary object, the video information of the camera 19 evaluated. This video information reproduces, for example, flashing brake lights of a preceding, sustained vehicle as information for an initiated braking operation. Also other video information, such as. B. Ampelrotlichter at intersections or at restricted or unrestricted level crossings, etc. can serve as an information signal for the appropriate reduction of the creep to avoid collisions with other vehicles, barriers, trains and the like.

Although the invention has been further illustrated and explained in detail by way of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of possible variations exists. It is also to be understood that exemplified embodiments are really only examples that are not to be construed in any way as limiting the scope, applicability, or configuration of the invention. Rather, the foregoing description and description of the figures enable one skilled in the art to practice the exemplary embodiments, and those of skill in the knowledge of the disclosed inventive concept may make various changes, for example as to the function or arrangement of individual elements recited in an exemplary embodiment, without Protection area defined by the claims and their legal equivalents, such as further explanations in the description.

LIST OF REFERENCE NUMBERS

1

vehicle

3

control unit

5

Internal combustion engine

7

transmission

9

electric motor

11

ultrasonic sensor

13

radar sensor

15

Proximity sensor

17

tilt sensor

19

camera

21

Distance calculating unit

23

obstacle

25

Target distance

27

Actual distance

29

Creep limit unit

31

Speed sensor

33

output

35

management

37

accelerator

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 19949204 A1 [0002]

Claims (10)

Method for controlling a creep torque of a vehicle, characterized in that the creeping torque is dependent on at least one environmental information of the vehicle ( 1 ), preferably during a parking process is reduced. Method according to claim 1, characterized in that with the aid of the environment information of the vehicle ( 1 ) Obstacles ( 23 ) are determined in a with the creep to be traversed track. A method according to claim 1 or 2, characterized in that the reduction of the creep torque in dependence on a speed of the vehicle ( 1 ) and a distance of the vehicle ( 1 ) to the obstacle ( 23 ) is determined. A method according to claim 3, characterized in that when detected by the environmental information impending collision of the vehicle ( 1 ) with the obstacle ( 23 ) the creep torque is reduced by control technology, in particular reduced to zero or switched off. Method according to at least one of the preceding claims, characterized in that the reduction of the creeping torque as a function of an actual distance ( 27 ) of the vehicle ( 1 ) to the obstacle ( 23 ) and a desired distance ( 25 ) of the vehicle ( 1 ) to the detected obstacle ( 23 ) he follows. Method according to at least one of the preceding claims, characterized in that the nominal distance ( 25 ) is determined depending on whether the detected obstacle ( 23 ) moves or stands, wherein the desired distance ( 25 ) to a moving obstacle ( 23 ) is set greater than the desired distance ( 25 ) to a standing obstacle ( 23 ). Method according to at least one of the preceding claims 1 to 5, characterized in that the nominal distance ( 25 ) of the vehicle ( 1 ) to the obstacle ( 23 ) at the time of occurrence, by the vehicle ( 1 ) is set to be overcome slope greater than when driving through a plane through the vehicle ( 1 ). Vehicle with a device for controlling a creep torque of a vehicle, with an electric drive ( 9 ) and / or an automatic coupling or clutch system comprising a clutch ( 7 ), the device ( 3 ) for controlling a creep torque a creep torque limiting unit ( 29 ), characterized in that the device is used as a control device ( 3 ) is formed, which with the electric motor ( 9 ), the control unit ( 3 ) with at least one sensor ( 11 . 13 . 15 . 17 . 19 ) for the detection of obstacles ( 23 ) in the vicinity of the vehicle ( 1 ) connected to one, in the control unit ( 3 ) distance calculation unit ( 21 ) for determining an actual distance and a desired distance ( 27 . 25 ) of the vehicle ( 1 ) to the obstacle detected in the environment ( 23 ), wherein the distance calculation unit ( 21 ) with the creep torque limiting unit ( 29 ) is coupled to reduce the creep torque. Vehicle according to claim 8, characterized in that the creep torque limiting unit ( 29 ) a map for determining the creep torque as a function of a vehicle speed and one of the desired distance ( 25 ) and the actual distance ( 27 ) determined difference distance of the obstacle ( 23 ) detected. Vehicle according to claim 8 or 9, characterized in that the at least one sensor ( 11 . 13 . 15 . 17 . 19 ) for detecting the obstacle ( 23 ) in the vicinity of the vehicle ( 1 ) Is part of a parking assistance system.

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