METHOD FOR OPERATING A MOTOR VEHICLE

Abstract

A method for operating a motor vehicle which is equipped with a driving dynamics control system by which individual wheels of the motor vehicle can be braked in a targeted manner. In order to prevent the occurrence of undesirable noises during maneuvering of the motor vehicle, during a maneuvering operation, in which two front wheels are turned with a large wheel lock, wherein friction occurs at the front wheels because of ground contact, one of the wheels is influenced in a targeted manner in order to pull or to force the motor vehicle onto a smaller turning circle during the maneuvering.

Claims

1. A method for operating a motor vehicle which is equipped with a driving dynamics control system by which individual wheels of the motor vehicle are configured to be braked in a targeted manner, the method comprising: influencing one of the individual wheels in a targeted manner in order to pull or to force the motor vehicle onto a smaller turning circle during a maneuvering operation in which two front wheels of the vehicle are turned with a large wheel lock causing friction at the front wheels because of ground contact.

2. The method as claimed in claim 1, wherein a rear wheel of the vehicle on an inside of a bend along a path travelled by the vehicle is braked in a targeted manner during the maneuvering process in order to reduce skewing of the front wheel on an outside of the bend.

3. The method as claimed in claim 1, wherein a rear wheel on an inside of a bend along a path travelled by the vehicle is driven in a targeted manner with a lower driving torque during the maneuvering operation in order to reduce skewing of a front wheel of the vehicle on an outside of the bend.

4. The method as claimed in claim 1, wherein a rear wheel on an outside of a bend along a path travelled by the vehicle is driven in a targeted manner with a greater driving torque during the maneuvering operation in order to reduce skewing of a front wheel of the vehicle on an outside of the bend.

5. The method as claimed in claim 1, wherein the front wheel of the vehicle on an outside of a bend along a path travelled by the vehicle is pulled onto the smaller turning circle.

6. The method as claimed in claim 1, wherein the front wheel of the vehicle on an inside of a bend along a path travelled by the vehicle is pulled onto the smaller turning circle.

7. A driving dynamics control system for operating a motor vehicle equipped with a driving dynamics control system by which individual wheels of the motor vehicle are configured to be braked in a targeted manner, the driving dynamics control system being configured to influence one of the individual wheels in a targeted manner in order to pull or to force the motor vehicle onto a smaller turning circle during a maneuvering operation in which two front wheels of the vehicle are turned with a large wheel lock causing friction at the front wheels because of ground contact.

8. A computer program product having a program code for operating the driving dynamics control system as claimed in claim 7.

9. A control unit for controlling the driving dynamics control system with the computer program product as claimed in claim 8.

10. A motor vehicle having a driving dynamics control system as claimed in claim 7.

11. A motor vehicle having a control unit as claimed in claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further advantages, features and details of the invention emerge from the description below in which various exemplary embodiments are described in detail with reference to the drawing, in which:

[0018] FIG. 1 shows a simplified illustration of a motor vehicle with a chassis which comprises two front wheel and two rear wheels, during a maneuvering operation, and

[0019] FIG. 2 shows a similar illustration as in FIG. 1, wherein one of the wheels is influenced or manipulated in a targeted manner during the maneuvering operation in order to pull or to force the motor vehicle onto a smaller turning circle during the maneuvering.

DETAILED DESCRIPTION OF THE INVENTION

[0020] A motor vehicle 1 with a chassis 3 is illustrated in highly simplified form in FIGS. 1 and 2. The chassis 3 comprises two steerable front wheels 11, 12 and two non-steerable rear wheels 13, 14.

[0021] The front wheels 11, 12 of the motor vehicle 1 are turned to a large extent, in particular to a maximum extent, to the right for the purpose of maneuvering, in particular for entering or leaving a parking space, in FIGS. 1 and 2. In the top view illustrated, the front wheels 11, 12 are pivoted to the right relative to a vehicle longitudinal axis.

[0022] In FIG. 1, the front wheel 11 on the inside of the bend describes a curved path 15. The front wheel 12 on the outside of the bend describes a forced curved path 16. A theoretical curved path 17 of the front wheel 12 on the outside of the bend is indicated between the curved paths 15 and 16.

[0023] The motor vehicle 1 is preferably a sports car which has only a limited construction space in the region of the front axles for the wheel lock during steering. The construction space limitation is caused firstly by large tire widths. Furthermore, the construction space is limited by the wheel lock in a specification of the turning circle. Furthermore, the construction space is limited by a rectilinear design of longitudinal members of the vehicle body.

[0024] A constriction caused by the construction space limitation can be kept within limits, for example, by means of relatively low Ackermann portions. This gives rise, for example during parking, in particular under certain weather conditions, to undesirable tire noises, even to tire hopping.

[0025] In the tests, investigations and measurements carried out within the scope of the present invention, it has been shown that the front wheel 12 on the outside of the bend slips to a greater extent than the front wheel 11 on the inside of the bend. Steps in the curved path 15 are intended to illustrate a stick-slip effect which, within the context of the present invention, is considered to be a cause of the undesirable noises during parking. The stick-slip effect means that the front wheel 12 on the outside of the bend intermittently slips during maneuvering, in particular parking, while the front wheel 11 on the inside of the bend does not show this effect.

[0026] It is indicated in FIG. 2, by means of a rectangle 20, that the motor vehicle 1 is equipped with a driving dynamics control system 20. By means of the driving dynamics control system 20, the driving dynamics of the motor vehicle 1 in extreme situations can be influenced with a targeted braking of individual wheels. It has been discovered within the context of the present invention that, with the driving dynamics control system 20, during parking or maneuvering of the motor vehicle 1, the phenomenon previously referred to as parking judder can also be influenced.

[0027] If the rear wheel 13 on the inside of the bend is braked by the driving dynamics control system 20, the motor vehicle 1 is pulled onto a smaller turning circle and the skewing and hence the parking judder of the front wheel 12 on the outside of the bend are reduced. The precise parameters of the targeted braking interventions are stored, for example, in a control unit (likewise only indicated by a rectangle 25) in the motor vehicle 1. Alternatively or additionally, a driving torque of at least one individual wheel can be influenced or manipulated in a targeted manner.

[0028] It is indicated in FIG. 2 by a curved path 21 that the front wheel 11 on the inside of the bend is pulled onto a smaller turning circle if the rear wheel 13 on the inside of the curve is braked. It is indicated by means of a curved path 22 that the front wheel 12 on the outside of the bend is likewise particularly advantageously pulled onto a smaller path which is freer of skewing when the rear wheel 13 on the inside of the bend is braked.