Method for stabilizing a vehicle in the event of tire pressure loss

Abstract

Method for stabilizing a vehicle in the event of tire pressure loss by means of a driving stability-related system, characterized in that the driving stability-related system can at least be deactivated manually and is automatically activated in the manually deactivated state when tire pressure loss is detected or when the tire pressure is below a predetermined threshold.

Description

[0001] The invention relates to a method and to a driving stability-related system, each for stabilizing a vehicle in the event of tire pressure loss.

[0002] Such a method is known, for example, from DE 102 30 967 A1. Here, a driving stability-related system takes the current tire pressure into account during special cornering control.

[0003] The object of the invention is to provide a simplified method for stabilizing a vehicle in the event of tire pressure loss.

[0004] This object is achieved according to the invention by the respective subject matter of the independent patent claims. Advantageous further developments are the subject matter of the dependent patent claims.

[0005] In a method for stabilizing a vehicle in the event of tire pressure loss, a driving stability-related system that can be manually activated and / or deactivated is automatically activated in the manually deactivated state when tire pressure loss is detected or when the tire pressure is below a predetermined threshold.

[0006] Preferably, the driving stability-related system remains deactivated if it has been manually deactivated again after automatic activation.

[0007] A driving stability-related system can be an electronically controlled longitudinal, lateral, and / or vertical dynamic control system. Such systems are known, for example, as ESP (Electronic Stability Program) or DSC (Dynamic Stability Control). These systems optimize driving stability, including traction. They detect unstable driving conditions such as understeer or oversteer, and help stabilize the vehicle by influencing engine power and / or by braking individual or multiple wheels. Systems such as DTC (Dynamic Traction Control), DBC (Dynamic Brake Control), AFS (Active Front Steering), DXC (X-Drive, all-wheel drive control system), Dynamic Drive (roll stabilization), or air suspension can also be considered driving stability-related systems, such as those found in today's BMW vehicles.For example, stabilizing braking interventions, drive interventions, steering interventions and shock absorber adjustment interventions or ride height changes are carried out.

[0008] Some of these systems can be manually turned on and off using a switch or button. A switch can be either a standard electrical hardware switch (or button) or a software switch (or button), such as those found in today's computer-assisted function selection programs with a control display, e.g., known as i-Drive or MMI (e.g., DSC or DTC software switches in the control display of a BMW i-Drive system).

[0009] The invention therefore prohibits or ignores manual deactivation of at least one of these driving stability-related systems if a critical condition - in particular a loss of tire pressure - is detected.

[0010] An embodiment of the invention is explained in more detail with reference to the drawing.

[0011] The single figure shows an electronic control unit 1, which is used, for example, to implement a DSC and / or DTC function. In addition to other input signals not shown here, the control unit 1 receives the signal from a tire pressure monitoring system 3 and a DTC button 2 in the form of an electrical hardware switch (or button), which is typically located in the cockpit of a vehicle.

[0012] The tire pressure monitoring system 3 monitors the tire pressure in the four mounted tires of a motor vehicle (not shown here) while driving. The tire pressure monitoring system 3 reports, for example, via a display if the pressure in one tire has dropped significantly compared to another, thus detecting a tire pressure loss. If the tire pressure monitoring system 3 detects a tire pressure loss in this or another way, the control unit 1 receives this information.

[0013] The DSC function in control unit 1 is always activated and prevents the drive wheels from spinning when starting off and accelerating. The DSC function also detects unstable driving conditions such as the rear of the vehicle skidding or the vehicle sliding over its front wheels. In these cases, the DSC function helps keep the vehicle on course by reducing engine power and / or applying the brakes to individual wheels. The DSC function is automatically activated every time the engine is started, but can be manually deactivated and reactivated using the DTC button 2.

[0014] A single, brief press of the DTC button 2 manually deactivates the DSC function, switching to the DTC function or leaving only this DTC function active. DTC (Dynamic Traction Control) is a variant of DSC optimized for propulsion under special road conditions, e.g., unplowed snowy roads. The DTC function ensures maximum propulsion, but with limited driving stability. The DTC function is automatically deactivated preferably at increased vehicle speeds (approx. > 70 km / h), or the increased DTC control thresholds are reset to the lower DSC control thresholds to maintain stability. This can occur suddenly above a certain speed threshold or continuously above the speed.

[0015] If a loss of tire pressure is now detected according to the invention, the tire pressure monitoring system 3 reports this to the control unit 1. The control unit 1 then automatically reactivates the (complete) DSC function when the DSC function is manually deactivated, ie when switching to the DTC function.

[0016] Deactivation of a system can therefore also be understood as a restriction of the system or a switching to another functional mode of the system, as in the case just described.

[0017] In addition, both the DTC and DSC functions can be deactivated, for example, by pressing and holding the DTC button 2. Even then, the control unit 1 automatically activates at least the DTC function, but preferably also the (complete) DSC function, if both functions were previously deactivated manually.

[0018] If one of the functions is then manually deactivated again because the driver intentionally wishes to do so, in a further development according to the invention it remains deactivated at least for the current ignition cycle, even if a loss of tire pressure has been detected.

[0019] The forced activation of DSC and / or DTC can be communicated to the driver via suitable displays (e.g. lamps, symbols, text messages) in the instrument cluster and / or in the Control Display.

[0020] In addition, in the event of a loss of tire pressure - in order to prevent the vehicle from tilting and thus not unnecessarily impairing longitudinal and lateral stability - the body can also be raised at the affected wheel via the air suspension.

Claims

[1] Method for stabilising a vehicle in the event of tyre pressure loss, by means of a driving stability-related system, characterized by that the driving stability-related system can at least be deactivated manually and, in the manually deactivated state, is automatically activated if tire pressure loss is detected or if the tire pressure is below a predetermined threshold. [2] Method according to claim 1, characterized by that the driving stability-related system remains deactivated for at least one current ignition cycle if it has been manually deactivated again after automatic activation. [3] Method according to claim 1 or 2, characterized bythat manually deactivating the driving stability-related system deactivates a dynamic stability control (DSC), whereby the driving stability-related system is switched to a functional mode in which it only provides a dynamic traction control (DTC). [4] Method according to one of the preceding claims, characterized by that a vehicle body is raised by means of an air suspension at a wheel of the vehicle which is subject to a loss of tyre pressure or has a tyre pressure below the specified threshold. [5] Driving stability-related system which is designed to carry out the method according to one of the preceding claims and is an electronically controlled longitudinal and / or transverse and / or vertical dynamics control system.

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