DE102017001205A1 - Method for operating a driver assistance system of a vehicle - Google Patents

Abstract

The invention relates to a method for operating a driver assistance system (1) of a vehicle, in which - a driver of the vehicle is supported while holding the vehicle on a lane, - a lane and an actual position (PIst) of the vehicle relative to the lane by means of a vehicle-own sensor (3) is detected and / or determined, - a position difference (ePos) between the actual position (PIst) of the vehicle and a predetermined desired position (PSoll) of the vehicle is determined and - an actual steering angle (δIst) of the vehicle detected and a steering angle difference (e steering) from the actual steering angle (δIst) and a predetermined target steering angle (δSoll) is determined. According to the invention, it is provided that - the steering angle difference (e steering) is smoothed by means of a filter (1.2.2) designed as a low-pass filter, - an amount (| e'-steering |) of the smoothed steering angle difference (e'-steering) is formed, - a deflection is detected if the amount (| e'-handle |) exceeds a predetermined limit value (G), - if an oversteer is detected, the steering angle difference (e-steering) is multiplied by a predetermined correction factor (x), - a product of the steering-angle difference (e-steering ) and the correction factor (x) resulting corrected steering angle difference (eLenk_korr) is subtracted from the position difference (ePos) and - depending on the difference between position difference (ePos) and corrected steering angle difference (eLenk_korr) an integral part of a controller (1.2) of the driver assistance system (1 ) is determined.

Description

The invention relates to a method for operating a driver assistance system of a vehicle according to the preamble of claim 1.

Methods for operating driver assistance systems are known from the prior art. For example, are off WO 2009/129890 A1 a method and apparatus for determining a corrective steering torque of a lane departure warning known. The lane departure warning system generates a controller torque, wherein the corrective steering torque of the lane departure warning system is formed by the difference between the controller steering torque and the amount of driver steering torque generated by the driver.

Furthermore, it is off DE 10 2005 033 866 A1 a steering system with auxiliary power assistance for motor vehicles, which comprises a steering actuator with which a support torque can be exerted on the steering of the vehicle. Furthermore, the steering system comprises a lane recognition system for determining information relating to the lane course, a reference model which calculates a reference steering angle as a function of the data obtained from the lane recognition system, and a transmission link which determines the assistance torque which is transmitted from the steering actuator to the steering in dependence on the driving state becomes. The transmission member is designed such that the zero position of the steering characteristic is equal to the reference steering angle and shifts in dependence on the lane course with the reference steering angle.

The invention is based on the object to provide a comparison with the prior art improved method for operating a driver assistance system.

The object is achieved with the features specified in claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims. In a method of operating a driver assistance system of a vehicle, a driver of the vehicle is assisted in keeping the vehicle on a lane. In this case, a lane and an actual position of the vehicle relative to the lane by means of an in-vehicle sensor, z. B. a camera system, lidar and / or radar sensors, etc., detected and / or determined. Furthermore, a position difference between the actual position of the vehicle and a predetermined desired position of the vehicle is determined, wherein an actual steering angle of the vehicle detected and a steering angle difference of the actual steering angle and a predetermined target steering angle is determined.

According to the invention, it is provided that the steering angle difference is smoothed by means of a filter designed as a low-pass filter, wherein an amount of the smoothed steering angle difference is formed, wherein a deflection is detected when the amount exceeds a predetermined limit, wherein when detecting an oversteer steering angle difference with a predetermined correction factor is multiplied, wherein a resulting from the product of the steering angle difference and the correction factor corrected steering angle difference is subtracted from the position difference and wherein an integral part of a controller of the driver assistance system is determined depending on the difference between position difference and corrected steering angle difference.

By means of the method, the desired position of the vehicle is influenced such that the desired steering angle is approximated to the current actual steering angle, at least for a certain period of time. This has the consequence that the vehicle is guided steadily and quietly in a subsequent return to the determined by the driver assistance system, optimal target position. Furthermore, the driver assistance system by means of the method can take into account actions of the driver which support the driver assistance system. This is the case, for example, with the influence of crosswinds, which can be detected earlier by the driver than by the driver assistance system. The driver and the driver assistance system thus support each other here.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

1 schematically a driver assistance system of a vehicle and

2 schematically a circuit diagram of a preprocessing stage for influencing a behavior of a controller of the driver assistance system.

Corresponding parts are provided in all figures with the same reference numerals.

1 schematically shows a block diagram with a driver assistance system 1 a non-illustrated vehicle and a steering device 2 of the vehicle.

The driver assistance system 1 includes a lane departure warning system 1.1 with a regulator 1.2 which a driver of the vehicle while lane keeping by means of a steering device 2 additionally introduced steering angle and / or an additionally introduced steering torque supported.

Input variables of the lane departure warning system 1.1 are recorded data of a vehicle's own sensors 3 , comprising z. As a camera system with at least one camera, Lidarsensoren and / or radar sensors, and other sensors 4 which detect, for example, a vehicle speed, a vehicle acceleration, etc. Using the data of the camera 3 a lane and an actual position of the vehicle relative to the lane are determined. The regulator 1.2 Thus, an actual position P _{actual of} the vehicle and a desired position P _set determined on the basis of various data are made available as an input variable.

Another input for the controller 1.2 is an actual steering angle δ _Ist , which is detected for example by means of a steering angle sensor, not shown. In particular, on a steering element, for. As a steering wheel, a generated by the driver, manual steering angle δ and detected as the actual steering angle δ _is the lane departure warning 1.1 transmitted. Furthermore, an optional steering torque M to the lane departure warning 1.1 be transmitted.

In addition, the controller can 1.2 vehicle-specific parameters and environmental parameters are supplied, which is a behavior of the controller 1.2 influence. For example, a mass and a length of the vehicle, a roadway moisture, etc. are detected and the controller 1.2 provided as an input.

As already mentioned, the lane departure warning system supports 1.1 the driver of the vehicle while tracking by means of a steering device 2 additionally introduced steering angle. For this purpose, the actual steering angle δ _Ist to one by means of the lane departure warning 1.1 predetermined target steering angle δ _setpoint (see 2 ) customized. When driving on a roadway, it is possible for the driver to temporarily get one from the driver assistance system 1 determined, want to leave optimal tracking. This may for example be the case in a construction site area where the driver decides to drive further to the left than the driver assistance system 1 Determined desired position P _{Desired by} the vehicle. The corresponding steering movement of the driver is also referred to as Überlenken. Here, however, is problematic that the driver assistance system 1 due to an integral part and thus an integrating behavior of the regulator 1.2 increasingly regulates and controls against the driver's steering movement. If the driver interrupts the steering movement after a certain time, the actual steering angle δ _{Ist would} immediately be adapted to the target steering angle δ _Soll and the vehicle could snap back and start to oscillate.

To solve the problem, a method for operating the driver assistance system 1 proposed, by means of which a deflection is detected and consequently the driver assistance system 1 can be influenced.

2 shows a circuit diagram of a preprocessing stage for influencing a behavior of the controller 1.2 , by means of which the method for operating the driver assistance system 1 is carried out.

The preprocessing stage shown has a first summing unit 1.2.1 on, which is the actual steering angle δ _Ist and the target steering angle δ _set to be supplied. In order to detect a deflection, is in the first summation unit 1.2.1 First, a steering angle difference e _steering from the target steering angle δ _target and the actual steering angle δ _Ist determined. The required values are determined by the Lane Keeping Assist 1.1 made available.

The steering angle difference e _steering is by means of a filter designed as a low-pass filter 1.2.2 smoothed. Subsequently, by means of an amount function 1.2.3 an amount | e ' _steering | the smoothed steering angle difference e ' _steering formed. The amount | e ' _steering | becomes a comparison unit 1.2.4 which checks whether the amount | e ' _steering | exceeds a predetermined limit value G. Exceeds the amount | e ' _steering | the predetermined limit value G, is determined by means of an evaluation unit 1.2.5 detected a Überlenken. Optionally, the evaluation unit 1.2.5 additionally the steering torque M from the steering device 2 to provide. Here, an oversteering is detected when the magnitude | e _'steering | exceeds the predetermined limit G and when the steering torque M has a certain value. The steering torque M is to do so by means of a conjunctive operator 1.2.6 the amount | e ' _steering | added and the evaluation unit 1.2.5 made available.

If a deflection is detected, the target position P _{desired of} the vehicle differs from the actual position P _actual in a lane due to a driver intervention. Usually, an integral part of the regulator 1.2 due to a position difference e _Pos between the desired position P _{target of} the vehicle and the actual position P _is the target steering angle δ _set steadily increase to approximate the actual position P _{actual of} the vehicle again to the desired position P _Soll . To counteract this, however, for reasons already mentioned, the steering angle difference e _{steering is} in a multiplying unit 1.2.7 multiplied by a correction factor x and a resulting corrected steering angle _difference e _{Lenk_korr} a second summing unit 1.2.8 fed. The second summing unit 1.2.8 Furthermore, the position difference e _{Pos is} supplied, which previously in a third summation 1.2.9 was determined.

In the second summation unit 1.2.8 the corrected steering angle _difference e _{Lenk_korr is subtracted} from the position _difference e _Pos and the result of an integrating unit 01/02/10 , which is an I-part of the regulator 1.2 represents, which is the integral part of the regulator 1.2 determined on the basis of the transmitted result.

The described steps of the pre-processing stage, in particular the mathematical operations, may vary in order. For example, the desired steering angle δ _setpoint and the actual steering angle δ _actual can also be multiplied by the correction factor x and then the steering angle difference e _steering can be formed.

By means of the control loop, the desired position P _{desired of} the vehicle is thus influenced in such a way that the target steering angle δ _target approaches the actual steering angle δ _actual for this period. This has the consequence that in a subsequent return of the vehicle to the predetermined optimum target position P _target, the vehicle is guided steadily and quietly.

LIST OF REFERENCE NUMBERS

1

Driver assistance system

1.1

Lane Departure

1.2

regulator

1.2.1

first summation unit

1.2.2

filter

1.2.3

absolute value function

1.2.4

comparing unit

1.2.5

evaluation

1.2.6

Konjunktionsoperator

1.2.7

Multierpliziereinheit

1.2.8

second summation unit

1.2.9

third summation unit

01/02/10

integrating

2

steering device

3

sensors

4

additional sensors

G

limit

M

steering torque

P _is

Actual position

P _target

Nominal position

e _steering

Steering angle difference

e ' _steering

smoothed steering angle difference

| e ' _steering |

Amount of the smoothed steering angle difference

e _{Lenk_korr}

corrected steering angle difference

e _Pos

position difference

x

correction factor

δ _target

Target steering angle

δ _is

Actual steering angle

δ

steering angle

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

• WO 2009/129890 A1 [0002]
• DE 102005033866 A1 [0003]

Claims (2)

Method for operating a driver assistance system ( 1 ) of a vehicle in which - a driver of the vehicle is assisted in keeping the vehicle on a lane, - a lane and an actual position (P _actual ) of the vehicle relative to the lane by means of an in-vehicle sensor system ( 3 ) is detected and / or determined, - a position difference (e _Pos ) between the actual position (P _actual ) of the vehicle and a predetermined desired position (P _setpoint ) of the vehicle is determined and - an actual steering angle (δ _actual ) of the vehicle detected and a steering angle difference (e _steering ) from the actual steering angle (δ _actual ) and a predetermined target steering angle (δ _Soll ) is determined, characterized in that - the steering angle difference (e _steering ) by means of a low-pass filter ( 1.2.2 ) an amount (| e ' _steering |) of the smoothed steering angle difference (e' _steering ) is formed, - a deflection is detected when the amount (| e ' _steering |) exceeds a predetermined limit value (G), upon detection of an oversteer, the steering angle difference (e _steering ) is multiplied by a predetermined correction factor (x), - a corrected steering angle _difference (e _{Lenk_korr} ) resulting from the product of the steering angle difference (e _steering ) and the correction factor (x) from the position _difference (e _Pos ) is subtracted and - depending on the difference of position difference (e _Pos ) and corrected steering angle difference (e _{Lenk_korr} ) an integrating portion of a controller ( 1.2 ) of the driver assistance system ( 1 ) is determined. A method according to claim 1, characterized in that in addition a manually generated by the driver steering torque (M) is detected, wherein a steering is detected when the amount (| e ' _steering |) of the smoothed steering angle difference (e' _steering ) the predetermined limit ( G) and when the detected steering torque (M) has a certain value.

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