Methods for controlling a steering system and steering system

Abstract

Method for controlling an externally assisted steering system (1) of a vehicle, wherein the vehicle has a navigation device (3) with which first technical data about a current road section (4) are determined, wherein steering assistance by the steering system (1) is dynamically adapted to the road section (4) by determining second technical data about the current road condition of the road section (4) by at least one detection means (2) of the vehicle, and the adaptation of the steering assistance is carried out taking into account both the determined first and the second technical data, characterized in that at least one steering assistance model is prestored and dynamically determined on the basis of the evaluation of the determined first and second technical data, wherein a steering assistance force is assigned to each steering assistance model as a setpoint.where the steering assistance force, pre-stored as a target value, is adjusted based on the evaluation.

Description

[0001] The invention relates to a method for controlling an externally assisted steering system for a vehicle according to the preamble of claim 1 or an externally assisted steering system suitable for carrying out this method according to the preamble of claim 2.

[0002] DE 100 07 357 A1 describes a device for controlling the chassis of a motor vehicle. The device comprises a chassis control unit, which has corresponding actuators for controlling the chassis and vehicle dynamics, and an information processing unit that provides information about the condition of a specific section of road to be traversed. Before traversing the road section, the chassis control unit receives this information from the information processing unit and performs a pre-setting of the chassis or parts thereof, the information processing unit being a navigation system. With this design, for example, the chassis or wheel suspension of the motor vehicle can be pre-set for the curve before driving through it.

[0003] German patent application DE 10 2007 007 442 A1 discloses a method for influencing an additional torque acting on a steering wheel. This additional torque varies depending on the determined coefficient of friction of a road surface. A curve radius of the road is determined using a navigation system in order to modify the additional torque based on the coefficient of friction to improve driving safety. The additional torque reduces the steering angle and steering wheel angle values ​​when the vehicle is in or approaching a lateral dynamic limit.

[0004] Furthermore, a vehicle of this type is shown in DE 10 2010 003 867 A1.

[0005] The invention is based on the objective of optimizing the steering assistance of an externally assisted vehicle steering system so that the steering behavior of the vehicle can be dynamically adapted to the current driving situation.

[0006] This problem is solved according to the invention by a method with the features of claim 1 or a steering system with the features of claim 2.

[0007] According to the invention, a method for controlling a power-assisted steering system of a vehicle is provided, wherein the vehicle has a navigation device with which first technical data about a current road segment are determined. Steering assistance of the vehicle's steering system is dynamically adapted to the road segment by determining second technical data about the current road condition of the road segment, in particular road surface irregularities, by means of at least one detection device of the vehicle, and by adapting the steering assistance taking into account both the determined first and second technical data. Steering assistance includes, for example, steering assistance force and return behavior, etc.By dynamically adjusting the steering assistance to both the vehicle's position and the current road surface condition of the section of road being driven over, steering comfort is increased when driving the vehicle.

[0008] For a particularly comfortable steering system setup for the driver, it is advantageous to adapt the steering system by pre-storing and dynamically determining at least one steering assistance model. A steering assistance model can, for example, belong to a charisma mode. A charisma mode allows the driver to better adapt the vehicle to their driving style, such as comfort or sportiness. The steering assistance force of the steering system is adjusted by pre-storing at least one steering assistance model and dynamically determining it based on the evaluation of the determined first and second technical data, with each steering assistance model assigned a target steering assistance force. The determination of a steering assistance model depends on the evaluation of the determined first and second technical data.The power steering force, pre-stored as a target value, is adjusted based on the evaluation of the first and second technical data points. This power steering model thus provides the driver with an adaptive driving profile that is tailored to both their driving style and the current road conditions.

[0009] Furthermore, a power-assisted steering system for a vehicle is described, whereby data can be communicated between the vehicle's navigation system and the steering system. The navigation system can determine initial technical data about a road segment, in particular its road alignment and driving environment. The steering system comprises a sensor for determining secondary technical data about the current road condition, especially road surface irregularities, whereby the sensor is functionally integrated either into the steering system or into a control unit that communicates with it. The steering assistance of the steering system can be adapted to the road segment based on a joint evaluation of the determined primary and secondary technical data.

[0010] According to the invention, at least one steering assistance model for adapting the steering system is pre-stored on a storage medium of the steering system and dynamically determined based on the evaluation of the determined first and second technical data, wherein each steering assistance model is assigned a steering assistance force as a target value for the steering assistance of the vehicle. In addition, the steering assistance force of the steering assistance model can also be adjusted based on the evaluation result.

[0011] The invention is described below in the context of an exemplary embodiment based on the Fig. 1 explained in more detail.

[0012] An externally assisted steering system is used to steer vehicles. When steering using an electromechanical steering system, an assisting force is generated by an electric motor as an auxiliary force in the steering system. A schematic representation of the invention shows an electromechanical steering system 1 of a vehicle, in which it interacts with a navigation device 3 of the vehicle.

[0013] Using the navigation device 3, initial technical data about the current position of a road section 4 to be traveled on is determined, in particular about its road course, such as in the case of many tight curves or a largely straight stretch, and the surrounding conditions. Furthermore, secondary technical data about the current road condition of this road section 4 are determined using a detection device 2. This secondary technical data can include road surface irregularities, the type of road surface, the road condition (e.g., wet, snowy, dry), and the roadbed, e.g., a well-maintained road with asphalt or cobblestones. This secondary data can be determined, for example, by observing and recording the road directly in front of the vehicle using a video camera. Alternatively or additionally, the road condition can also be determined through real-time feedback from the road surface via the vehicle's suspension.Particularly when anticipating the road surface, it is possible to adjust the steering system 1 in advance in order to automatically adapt to the road surface of the road section 4 to be crossed.

[0014] Through a joint evaluation of the determined first and second technical data, namely a current evaluation of the position information and the current road surface condition of a road section 4 to be traveled, steering assistance is dynamically adapted to both the road profile and road surface irregularities. This improves the steering feel and / or increases driver comfort. The adaptation of the steering system 1 can also be further enhanced by determining a steering assistance model based on the evaluation result, with at least one steering assistance model being stored on a memory device 5 of the steering system 1. Each steering assistance model is assigned a steering assistance force as a target value for the steering system 1. Based on the evaluation, the steering assistance force can also be modified accordingly so that the steering assistance model is dynamically adapted to the current road surface condition.

[0015] For example, if navigation device 3 generates a message indicating that the road is cobblestone, steering system 1 can react by selecting a steering assistance model with less steering force, thus providing the driver with less feedback from the road and therefore greater driving comfort. If navigation device 3 sends a message indicating, for example, that the driver must navigate a road with many tight curves, steering system 1 reacts by selecting a corresponding steering assistance model with greater steering assistance. The driver can then navigate the curves comfortably and with a pleasant tactile experience.

Claims

[1] Method for controlling a power-assisted steering system (1) of a vehicle, wherein the vehicle has a navigation device (3) with which first technical data about a current road section (4) are determined, wherein a steering assistance by the steering system (1) is dynamically adapted to the road section (4) by determining second technical data about the current road condition of the road section (4) by at least one detection means (2) of the vehicle, and the adaptation of the steering assistance is carried out taking into account both the determined first and the second technical data, characterized bythat at least one steering assistance model is pre-stored and dynamically determined on the basis of the evaluation of the determined first and second technical data, wherein each steering assistance model is assigned a steering assistance force as a target value, wherein the steering assistance force pre-stored as a target value is set on the basis of the evaluation. [2] Power-assisted steering system (1) of a vehicle, wherein data can be communicated between a navigation device (3) of the vehicle and the steering system (1), wherein the navigation device (3) can determine first technical data about a current road section (4), wherein the steering system (1) comprises at least one detection means (2) for determining second technical data about the current road condition, and that a steering assistance by the steering system (1) can be dynamically adapted to the road section (4) by determining second technical data about the current road condition of the road section (4) by the detection means (2), and the adaptation of the steering assistance takes place taking into account both the determined first and the second technical data, characterized byin that the steering system (1) has a storage means (5) for storing at least one steering assistance model which is provided for adapting the steering assistance, wherein each steering assistance model is assigned a steering assistance force as a target value, wherein the steering assistance force pre-stored as a target value can be adjusted on the basis of the evaluation.

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