DE102005022405A1 - Method for protection of occupants of motor vehicle in event of pressure drop in tire entails bringing vehicle into safe operating state in case of falling below of minimum value and/or exceeding of pressure gradient of tire pressure - Google Patents

Abstract

The method for protection of occupants of a motor vehicle in the event of a pressure drop in at least one tire (12) entails bringing the vehicle into a safe operating state in the case of falling below of a minimum value and/or exceeding of a pressure gradient of the tire pressure. Reversible safety systems are activated in the safe operating state. In the safe operating state, windows (6,7) and/or sliding roof (11) are closed, at least one door lock (8,9) and/or luggage compartment (10) and/or fuel tank flap (21) are unlocked or locked. An independent claim is included for a device for protection of occupants of a motor vehicle in the event of a pressure drop in at least one tire.

Description

The The present invention relates to a method for protecting vehicle occupants with drop in pressure in at least one vehicle tire, wherein the Tire pressure is measured directly or indirectly

Directly Measuring systems for tire pressure monitoring capture the absolute Tire pressure with pressure sensors and send the information e.g. wireless to a receiver in the vehicle for further evaluation or display. Indirect systems such as. the TIMS (Tire Inflation Monitoring System) or the DWS (Dunlop Warning System) inform the driver about larger pressure deviations in one of the Tires. This system is based on the principle that a tire with Lower tire pressure has a lower rolling circumference than a tire rolling with correct tire pressure. The pressure difference is measurable as differential speed and is evaluated accordingly.

The Speed sensors and thus the wheel speed information stand with the systems ABS, ASR or ESP available. They are corresponding in a control unit the TIMS / DWS algorithms further processed.

One Pressure drop of about 30% leads typically to a wheel speed increase of about 0.2 ... 0.5. The Systems detect pressure losses of more than 30% (+/- 10% tolerance) in relation to normal pressure. Recognition times are 30% pressure drop at less than 3 minutes, at 50% pressure drop at less than 1 minute.

For the active Safety is the tire pressure information used to the control strategies of a ESP / ABS Systems to improve.

From the DE 10210928 a system is known, which controls a reversible belt tensioner, wherein the value of the drop in the tire pressure of at least one tire is detected continuously and when a threshold value is exceeded the triggering of the belt tensioner and airbag is controlled. The detection of the tire pressure is based here on the measurement of the absolute tire pressure by means of a pressure sensor in the tire.

Problems of the State of the art

adversely in known systems is insufficient occupant protection. The object of the invention is therefore to improve occupant protection to achieve.

Advantages of invention

This Problem is solved by a method for protecting vehicle occupants in case of drop in air pressure in at least one vehicle tire, with the tire pressure directly or is measured indirectly, which falls below a minimum value and / or exceeding a pressure gradient of tire pressure the vehicle into a safe Operating condition is brought.

Of the Tire pressure is the air pressure in the vehicle tires. In the safe Operating state can preferably reversible safety systems are activated. Of Furthermore, it is preferably provided that in the safe operating state window and / or sunroof closed. Additionally or alternatively, in the safe operating state at least one door lock and / or a Trunk and / or a fuel cap to be unlocked.

alternative can at least one door lock in the safe operating state and / or a trunk and / or a gas cap are locked.

In addition, can be provided that at least one of the seats in a safe Position is brought. The safe position is a seat adjustment, e.g. Position of the backrest, Position opposite the steering wheel, seat height and inclination etc., in the one possible low risk of injury for the occupant (s) exists. Furthermore, it can be provided that the steering wheel position is brought into a safe position. additionally the hazard warning light can be switched on.

Of Furthermore, it is possible to intervene actively in engine management on the one hand to move the driver to a tire-friendly driving style and to avoid critical driving situations, e.g. by doing the drive torque of the drive motor is limited. The desired moment The driver is thus only met up to an upper limit. Of Further can be actively intervened in the driving situation, for example by the vehicle is actively braked.

The above-mentioned problem is also solved by a device for protecting vehicle occupants at drop in pressure in at least one vehicle tire, wherein at least one of the vehicle tires is associated with a directly or indirectly measuring tire pressure sensor, which provides a signal to a control unit, wherein means for determining a pressure deviation are provided by the desired pressure and / or means for determining a pressure gradient of the tire pressure and that means when falling below a minimum value of the tire pressure and / or exceeding a pressure gradient of the tire pressure can bring the vehicle in a safe operating condition.

The Detection of tire pressure information is based on wheel speeds or wheel speeds around in case of a critical driving situation, e.g. a quick pressure loss or tire blow reversible Activate systems and / or warning devices. Core of the invention is the activation of protective mechanisms (active and passive restraint systems) and / or comfort (window / sunroof, seating position, steering wheel position) and / or Warning devices (hazard warning lights / door locking system) and / or engine management (Removal of the drive torque) and / or active braking systems (braking of the vehicle) based on wheel speeds in the event of tire inflation pressure loss at least one wheel and / or critical driving situations, which indirectly via Wheel speeds can be detected.

advantage This method is that no additional sensors for detection Tire pressure is necessary to in case of a critical driving situation like sudden Pressure loss on at least one tire corresponding protection mechanisms to activate. Another advantage is the stabilization of the vehicle for avoiding accidents by removing the drive torque (for example disengaging or active engine management) in the event of a sudden pressure loss. this includes also falls the control of active systems such as ESP, i. Construction of appropriate Control strategies for accident prevention and stabilization of the vehicle. Furthermore you can by driving comfort and warning devices, e.g. of the Hazard warning system other road users on the critical driving situation Be advised of what is possibly about vehicle-vehicle communication is feasible. The inmates are in case of pressure loss in terms of occupant position in a favorable for a possible accident Position brought and / or window and / or sunroof closed and depending on the vehicle type e.g. Türschliessanlage open or closed to throw out in the event of an accident to avoid inmates.

The Wheel speeds or the wheel speed are determined by means of suitable Sensing detected and available on the CAN bus or in a control unit. The evaluation sees the monitoring the wheel speeds, which at a lower tire pressure or rise a tire blower, since the rolling circumference of the wheel is lower is and thus the speed of the wheel is increased. The wheel speeds are related to each other. Results in a noticeable greater deviation of Wheel speeds to each other leaves on a critical driving situation and / or a Reifenfülldruckverlust shut down.

drawings

following is an embodiment of Present invention explained in more detail with reference to the accompanying drawings. there demonstrate:

1 a sketch of a motor vehicle;

2 a sketch of the procedure.

A motor vehicle 1 includes a body 2 each with a left and right front door 3 and a left and right rear door 4 and a trunk lid 5 , In 1 shown is the left side of the vehicle. The front doors 3 are each with a disc 6 equipped, for example

open by sinking in the door. Accordingly, the rear doors 4 with slices to open 7 fitted. The front doors 3 each with a front door lock 8th The rear doors can be locked with a rear door lock 9 be locked, the trunk lid 5 can with a trunk lock 10 be locked. Of course, in each case for the left and right door own door locks available, here is the sake of clarity, only the left side of the vehicle, so therefore only the left front and rear door lock described. The door locks 8th . 9 . 10 are electrically controlled, eg as part of a central locking system. The body 2 further includes a sunroof 11 , which can also be opened and closed electrically and an electrically lockable tank lid 21 , The driver's seat, not shown, and the passenger seat can be changed in seat height, seat angle, angle of the backrest with electric actuators, the seats can also be moved in the vehicle longitudinal direction. The steering wheel, also not shown, can be axially displaced with electrical actuators along its axis of rotation and tilted about a horizontal axis extending transversely to the direction of travel.

The chassis of the motor vehicle 1 includes four wheels 12 , each with a tire pressure sensor 13 are equipped. The tire pressure sensor may in a known manner directly the tire pressure via a pressure sensor disposed in the rim or in the tire, and an electrical signal to a sensor which is arranged fixed to the body, transmits executed, or alternatively as so-called indirect Tire sensor, eg about a deformation of the tread of the tire 12 can measure the tire pressure. In 1 only one tire pressure sensor on a front wheel is shown by way of example. The other wheels also have tire pressure sensors. The electrical signal from the tire pressure sensor becomes a display 14 supplied, this may be, for example, a warning light, an LCD display or the like in the field of vision of the driver. At the same time the signal becomes a control unit 15 supplied, which is the signal of the pressure sensor 13 further processed. First, the pressure difference from the actual pressure pt to the setpoint pressure ps Δp = ps-pt is calculated. In addition, a differential quotient dp / dt or a difference quotient Δp / Δt is determined. The desired pressure ps is the pressure which is predetermined for the respective tire as the desired value and can be stored, for example, in a non-volatile memory.

The difference signal Δp becomes a comparator 16 , the differential quotient dp / dt a second comparator 17 fed. In the first comparator, it is determined whether the pressure difference Δp is greater than an allowable pressure difference Δps, that is, whether the deviation of the target pressure is greater than an allowable value. In the second comparator 17 it is determined whether the pressure gradient dp / dt or Δp / Δt is greater than a maximum allowable value. If either the pressure gradient dp / dt or Δp / Δt is greater than the permissible value or the differential pressure is greater than a maximum permissible value, then a trigger control 18 activated. At the same time, the corresponding signal is made available to other control devices of the motor vehicle, for example via a CAN bus, so that these, for example, a crash evaluation unit 19 with an accident triggering control 20 For example, to control airbags or the like can be further processed.

The trigger control 18 is electric with the latches 8th . 9 . 10 , electric windows for the windows 6 . 7 and an electric locking device for the sunroof 11 connected. For the sake of simplicity, in 1 the Verbindun conditions not shown to the electric windows, these are comparable to those of the respective locks of the doors. Is the trigger control 18 activated, the closing devices 8th . 9 . 10 unlocked (or locked if cheaper for the vehicle type). The sunroof 11 is brought into a closed position. The window 6 . 7 will be closed. The driver and passenger seats as well as the steering wheel are brought into a safe position for an accident, in which the risk of injury is minimized. The hazard warning light is switched on, the engine management limits the available torque and an electrically controlled brake actively brakes the vehicle if necessary (eg at too high a speed).

• • Reversible Systeme (reversibler Gurtstraffer zur Fixierung der Insassen und/oder Gurtstraffer)
• • Aktive Systeme (eine für einen Fülldruckverlust angepasste Regelstrategie eines Fahrdynamikregelsystems (ESP) zur Stabilisierung aufgrund von heftigen Lenkreaktionen des Fahrers)
• • Motormanagement – Wegnahme des Antriebsmoments (Auskuppeln) zur Unfallvermeidung durch Fahrerreaktion auf den Reifenplatzer (Gasgeben etc.)
• • Eingriff in die Bremsaktuatorik
• • Warneinrichtung – z.B. Aktivierung der Warnblinkanlage zur Kennzeichnung des kritischen Fahrzustandes für andere Fahrzeuge und/oder Fahrzeug-Fahrzeug Kommunikation
• • Komfortsysteme – Schließen von Fenster- und/oder Schiebedach, Anpassung der Sitzposition
• • Schliesssysteme – Öffnen oder Schließen der Türschliessanlage, Kofferraum, Tankdeckel etc.
• • Airbagsteuergerät – Schwellensenkung des Crashauslöseverfah rens
• • Aktivsitze – Änderung der Sitzposition, pneumatisch oder elektrisch

In 2 is shown schematically the procedure of the method. The wheel speed sensors on all four wheels detect in step 101 the wheel speeds nR1 to nR4, where the index 1 to 4 stands for the individual wheels. The wheel speeds nRX will be in step 102 to a wheel pressure loss ptX, where X is the index for the individual wheels, converted. In step 103 it is evaluated whether one of the wheel pressures has too large a pressure difference to the setpoint pressure ps Δp = ps - pt. Parallel will be in step 104 evaluated whether the pressure gradient dp / dt or Δp / At one of the wheels is greater than a maximum allowable value. The respective values are in step 105 in relation to each other and detect a critical driving condition, which can be caused by a tire inflation pressure loss, for example. If absolutely measuring tire pressure sensors are available, they can be checked for plausibility according to step 106 be involved. Also optional signals from existing control devices such as ESP and / or airbag ECU and / or other control devices can be used for plausibility. In step 107 it is checked whether a critical driving condition exists. If this is not the case (N), then the beginning at step 101 this is the case (J) so gets in step 108 depending on the degree of Fülldruckverlustes and / or the driving situation corresponding systems driven. These include:

• • Reversible systems (reversible belt tensioner to fix the occupants and / or belt tensioners)
• Active systems (a control strategy of a vehicle dynamics control system (ESP) adapted for a filling pressure drop for stabilization due to violent steering reactions of the driver)
• • Engine management - Removal of drive torque (disengagement) to avoid accidents due to driver reaction to the puncture of the tire (accelerating, etc.)
• • Intervention in the brake actuator
• • Warning device - eg activation of the hazard warning device to indicate the critical driving condition for other vehicles and / or vehicle-vehicle communication
• • Comfort systems - closing the window and / or sunroof, adjusting the seating position
• • Locking systems - opening or closing the door locking system, boot, fuel cap etc.
• • Airbag control unit - Threshold reduction of the crash triggering method
• • Active seats - change the seating position, pneumatically or electrically

Claims (10)

Method for protecting vehicle occupants in the event of a drop in air pressure in at least one vehicle tire ( 12 ), whereby the tire pressure (pt) is measured directly or indirectly ( 13 ), characterized that falls below a minimum value (ps) and / or exceeding a pressure gradient (Δp / Δt) of the tire pressure, the vehicle is brought into a safe operating condition. Method according to claim 1, characterized in that that in the safe operating condition reversible safety systems to be activated. Method according to one of the preceding claims, characterized in that in the safe operating state windows ( 6 . 7 ) and / or sunroof ( 11 ) getting closed. Method according to one of the preceding claims, characterized in that in the safe operating state at least one door lock ( 8th . 9 ) and / or a trunk ( 10 ) and / or a fuel cap ( 21 ) are unlocked. Method according to one of the preceding claims, characterized in that in the safe operating state at least one door lock ( 8th . 9 ) and / or the trunk ( 10 ) and / or the fuel cap ( 21 ) are locked. Method according to one of the preceding claims, characterized characterized in that at least one of the seats in a safe Position is brought. Method according to one of the preceding claims, characterized characterized in that the steering wheel is brought into a safe position becomes. Method according to one of the preceding claims, characterized characterized in that the hazard warning light is turned on. Method according to one of the preceding claims, characterized characterized in that the drive torque of the drive motor limited is and / or the vehicle is actively braked. Device for protecting vehicle occupants in case of drop in air pressure in at least one vehicle tire ( 12 ), wherein at least one of the vehicle tires ( 12 ) a directly or indirectly measuring tire pressure sensor ( 13 ), which sends a signal to a control unit ( 15 ), characterized in that means ( 16 ) for determining a pressure deviation from the target pressure and / or means ( 17 ) are present for determining a pressure gradient of the tire pressure and that means ( 8th . 9 . 10 . 165 . 17 . 18 . 19 . 20 . 21 ) If the tire pressure falls below a minimum value (ps) and / or if a pressure gradient (Δp / Δt) of the tire pressure is exceeded, the vehicle can be brought into a safe operating state.