Bremsregelsystem

Abstract

Brake control system for a motor vehicle (F) with at least one electronic control unit (2) for performing a hill descent control function, with an off-road button (3) and with an HDC button (4), wherein the control unit (2) is designed to detect predefined parameters for distinguishing between a comfortable and an uncomfortable downhill descent, and to activate a first comfort-oriented hill descent control mode (M1) when a comfortable downhill descent is detected and a second sport-oriented hill descent control mode (M2) when an uncomfortable downhill descent is detected, wherein different drive and / or brake control behaviors are assigned to the two modes (M1, M2).wherein the electronic control unit (2) can detect a signal from the manually operated off-road button (3) to activate an off-road mode and wherein the HDC button (4) can be operated to activate or deactivate the hill descent control system, characterized in that when the off-road mode is activated by the off-road button (3) and when the hill descent control system is simultaneously activated by the HDC button (4), the sport-oriented hill descent control mode (M2) can be activated, and when the off-road mode is deactivated by the off-road button (3) and when the hill descent control system is simultaneously deactivated by the HDC button (4), the comfort-oriented hill descent control mode (M1) can be activated.

Description

[0001] The invention relates to a brake control system for a motor vehicle with a hill descent control system.

[0002] Hill Descent Control (HDC) systems have been a known technology for many years, particularly in all-wheel-drive vehicles. These systems maintain a constant vehicle speed, such as 8 km / h, during steep descents by automatically applying the brakes. The driver can activate the system by pressing a button in the vehicle and, if necessary, adjust the desired (low) target speed.

[0003] For example, German patent DE 10 2009 030 346 A1 discloses a combination of an adaptive cruise control (ACC) system with a hill descent control (HDC) system such that the HDC system is automatically activated based on detected parameters when the need is recognized. The system is designed to detect the need to activate the HDC system or hill descent control when the vehicle's actual speed is below a relatively low speed threshold (between 3 and 25 km / h). At such a relatively low speed, the vehicle may be descending on relatively difficult terrain (off-road), and therefore, it is proposed to activate hill descent control in this range.

[0004] The need for hill descent control can also be detected if the vehicle's target speed is lower than a second speed threshold. In addition to, or as an alternative to, hill descent control being activated based on the actual speed, it can also be activated based on the driver's target speed.

[0005] Furthermore, the need for downhill speed control can be detected when a road gradient exceeds a certain threshold, particularly 15%. The road gradient can be easily detected using longitudinal inclination sensors or indirectly via acceleration sensors in the vehicle. Activation of downhill speed control based on the road gradient can also be combined with activation based on the target speed and / or actual speed.

[0006] The invention is based on the objective of further improving a brake control system for a motor vehicle with a hill descent control system.

[0007] According to the invention, this problem is solved by the features of the independent claims, while preferred embodiments of the invention are specified in the dependent claims.

[0008] Even with parameters that can be measured and evaluated in a known manner, such as gradient and speed, or slippage and wheel contact, or information from a navigation system, it is possible to differentiate between an uncritical or rather comfortable downhill drive, e.g., on a highway, and a critical or rather uncomfortable downhill drive, e.g., off-road or on difficult terrain. This differentiation can also be made by activating or not activating an off-road button, if provided in the vehicle, or by the automatic detection of off-road terrain.

[0009] According to the invention, a distinction is made between a more comfortable and a more uncomfortable downhill descent. Upon detection of a comfortable downhill descent, a first, comfort-oriented downhill control mode is activated. Upon detection of a more uncomfortable downhill descent, a second, more sport-oriented downhill control mode is activated. Both modes are associated with different drive and / or brake control characteristics.

[0010] The drawing illustrates an embodiment of the invention. The single figure schematically shows an overview of the essential components of the invention.

[0011] The single figure shows a motor vehicle K with a drive and / or brake unit. 1 as part of the brake control system according to the invention, with at least one of the drive and / or brake unit 1 assigned electronic control unit 2, with an off-road button 3 and with an HDC button 4 The HDC button is shown. 4 It is used to activate or deactivate the downhill speed control system.

[0012] The control unit 2 In addition to other drive and / or braking functions, it serves to perform a basic downhill driving control function. According to the invention, it is designed such that it determines the actuation state of the off-road button. 3 to distinguish between a more comfortable downhill run and a more uncomfortable downhill run.

[0013] When off-road mode is activated, especially via the off-road button 3 , and with the hill descent control system activated at the same time, in particular by the HDC button 4 , the more sport-oriented downhill control mode M2 activated.

[0014] With off-road mode deactivated, especially by the off-road button 3 , and with the hill descent control system deactivated at the same time, in particular by the HDC button 4 , the more comfort-oriented downhill control mode M1 activated.

[0015] In principle, the brake control system can include both the control of the (negative) drive torque and the control of the wheel brake.

[0016] The activation and deactivation of the basic downhill driving control function can also be performed automatically depending on the evaluation of predefined parameters.

[0017] Similarly, the selection of the two downhill control modes can be made M1 or M2 This can also happen automatically depending on the evaluation of predefined parameters. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102009030346 A1

[0003]

Claims

[1] Brake control system for a motor vehicle (K) with at least one electronic control unit (2) for performing a hill descent control function, wherein the control unit (2) is designed in such a way that it detects predefined parameters for distinguishing between a more comfortable downhill descent and a more uncomfortable downhill descent and that, when a comfortable downhill descent is detected, it activates a first comfort-oriented downhill control mode (M1) and, when a more uncomfortable downhill descent is detected, it activates a second sport-oriented downhill control mode (M2). [2] Brake control system according to claim 1, characterized by , that the electronic control unit (2) can detect a signal from a manually operated off-road button (3) and that when the off-road button is pressed to activate an off-road mode, the more sport-oriented hill descent control mode (M2) can be activated. [3] Brake control system according to one of the preceding claims, characterized by , that the electronic control unit (2) can detect a signal from a manually operated off-road button (3) and that when the off-road button is pressed to deactivate an off-road mode, the more comfort-oriented hill descent control mode (M1) can be activated. [4] Electronic control unit (2) for the brake control system according to one of the preceding claims. [5] Software function module for the at least one electronic control unit (2) of the brake control system according to one of the preceding claims.

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