WO2002098715A1 - Detecteur destine a un systeme de securite - Google Patents

Detecteur destine a un systeme de securite Download PDF

Info

Publication number
WO2002098715A1
WO2002098715A1 PCT/SE2002/001030 SE0201030W WO02098715A1 WO 2002098715 A1 WO2002098715 A1 WO 2002098715A1 SE 0201030 W SE0201030 W SE 0201030W WO 02098715 A1 WO02098715 A1 WO 02098715A1
Authority
WO
WIPO (PCT)
Prior art keywords
speed
bumper
detector according
vehicle
fender
Prior art date
Application number
PCT/SE2002/001030
Other languages
English (en)
Inventor
Rikard Fredriksson
Yngve Haland
Original Assignee
Autoliv Development Ab
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB0113525.0A external-priority patent/GB0113525D0/en
Application filed by Autoliv Development Ab filed Critical Autoliv Development Ab
Publication of WO2002098715A1 publication Critical patent/WO2002098715A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/013—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over
    • B60R21/0132—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/013—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over
    • B60R21/0132—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value
    • B60R21/0133—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value by integrating the amplitude of the input signal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/013—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over
    • B60R21/0134—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over responsive to imminent contact with an obstacle, e.g. using radar systems
    • B60R2021/01345—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over responsive to imminent contact with an obstacle, e.g. using radar systems using mechanical sensing means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/34—Protecting non-occupants of a vehicle, e.g. pedestrians

Definitions

  • THE PRESENT INVENTION relates to a detector for a safety arrangement in a motor vehicle and more particularly relates to a detector for a safety arrangement of the type which is deployed in response to an impact between the front part of the vehicle, typically a bumper or fender, and an object in the path of the vehicle, such as a pedestrian.
  • a problem with devices of this type is that the sensors presently utilised are not capable of distinguishing between an impact with a pedestrian and an impact with a fixed object such as a pole or post, or even an impact with another vehicle.
  • the present invention seeks to provide an improved detector for a safety arrangement.
  • a detector for a safety arrangement in a motor vehicle and adapted to detect an impact between the bumper or fender of the vehicle and another object, the detector comprising a sensor to determine a parameter related to the speed of at least part of the bumper or fender, and a signal generator to generate a triggering signal for the safety device if the parameter related to speed is below a first predetermined value.
  • the speed of at least part of the bumper or fender may be measured relative to the chassis of the vehicle.
  • the parameter related to speed may be simply speed, or may be some derivative of speed such as an increase in speed, or even relative increase, or decrease, in speed.
  • the bumper or fender is provided at least one said sensor in the form of an accelerometer to provide a signal representative of the acceleration of the bumper or fender.
  • two said accelerometers are provided, and averaging means are provided to determine the mean acceleration as measured by the two accelerometers from which the parameter related to speed is derived
  • the parameter related to speed of the bumper is calculated as an integral of the signal from the accelerometer or averaging means.
  • the parameter related to speed which is compared with the first predetermined value is the maximum speed that is measured during a predetermined period of time following the sensing of an impact.
  • the parameter related to speed which is compared with the first predetermined value is the speed that is measured at the end of a predetermined period of time following the sensing of an impact.
  • the said predetermined period of time is approximately 30 ms.
  • the triggering signal is generated when the parameter related to speed value is below the first predetermined value, but above a second predetermined value.
  • the first predetermined value is dependent upon the instantaneous measured speed of the vehicle, there being means to determine the speed of the vehicle, and to calculate the first predetermined value from the determined vehicle speed.
  • the predetermined speed value is 20 km/h.
  • the bumper or fender is provided with a contact strip sensitive to impact with an object to generate a contact signal to initiate operation of the signal generator.
  • the contact strip is responsive to the width of the part of an impacting object contacting the contact strip, and the detector is such that if the width of the object exceeds a predetermined threshold, generation of the triggering signal is inhibited.
  • the detector incorporates a calculator to determine the parameter related to speed by calculating the integral of the acceleration of the bumper or fender relative to the acceleration of the vehicle.
  • the bumper has a said sensor in the form of an accelerometer and the vehicle has an accelerometer, the outputs of the accelerometers being subtracted and integrated.
  • the bumper has a said sensor in the form of an accelerometer and a memory to store the instantaneous acceleration which is fixed in the event of an impact, the outputs of the accelerometer and the memory being subtracted and integrated.
  • the parameter related to speed is derived from a sensor responsive to the relative speed between the bumper or fender and the chassis of the vehicle.
  • FIGURE 1 is a partially sectional and partially diagrammatic illustration of a detector for a safety arrangement incorporating the invention.
  • FIGURE 2 is a block diagram provided for purposes of explanation.
  • a detector arrangement is shown on a motor vehicle.
  • Part of the chassis 1 of the vehicle is shown, with the chassis supporting a front beam 2 which extends transversely across the front of the vehicle and forms part of the bumper or fender 3.
  • the beam 2 supports an inner core 4 of the bumper formed of a foamed resilient material, and an outer bumper covering 5.
  • Mounted between the outer covering 5 and the foam core is a contact strip 6 which is adapted to sense contact between the exterior of the bumper or fender 3 and, for example, a pedestrian 7, and to provide a contact signal.
  • the contact strip 6 is adapted to distinguish and measure the width x of an objection, such as the pedestrian 7, which comes into contact with the bumper or fender, and in this embodiment is adapted to generate a specific signal if an object which has a width less than a predetermined width impacts with the bumper or fender 3.
  • the contact strip 6 may thus be divided into discrete zones, each providing a contact signal when in contact with an object, the number of zones providing a signal at one instant giving an approximate indication as to the width of the object.
  • the resistance of the contact path established when an object impacts with the bumper may be related to the width of the object.
  • accelerometers 8, 9 Associated with the beam 2 of the bumper or fender 3 are two sensors in the form of accelerometers 8, 9, which are located respectively to the left of, and to the right of, the central axis of the vehicle.
  • the accelerometers are adapted and configured to sense the acceleration of the bumper or fender, and may, in alternative embodiments, be located to the front of the bumper or fender, thus being located between the contact strip 6 and the foam core 4. In some embodiments of the invention, only one accelerometer or more than two accelerometers may be provided.
  • the accelerometers 8 and 9 each provide a respective output signal, with the respective output signals being forwarded to an averaging circuit 10, wliich determines the average or mean acceleration of the bumper or fender as sensed by the accelerometers.
  • the averaged acceleration signal from the averaging circuit 10 is forwarded to a subtraction circuit 11 which also receives an input from a further accelerometer 12, with the further accelerometer 12 being mounted on the chassis of the vehicle.
  • the output of the subtraction circuit 11, is therefore, a signal which is representative of the acceleration of the bumper or fender 3 relative to the vehicle.
  • the subtraction circuit 11 and the associated accelerometer 12 may be omitted so that a signal is passed which is a measure of the absolute acceleration of the bumper or fender 4 as measured by the accelerometer.
  • the accelerometers associated with the bumper or fender 3 provide an output to a memory which stores the instantaneous value. In the event of an impact with the bumper or fender this value is stored and is subtracted from the subsequent signals from the accelerometers, which provides a signal related to the acceleration of the bumper or fender relative to the initial acceleration of the vehicle.
  • a sensor senses the acceleration of the bumper relative to the main part of the vehicle.
  • the measured acceleration signal is passed to an integration circuit 13 which integrates the acceleration signal with respect to time, thus producing a speed or velocity signal v.
  • the speed or velocity signal v is passed to a discriminator 14.
  • the discriminator 14 in the described embodiment of the invention is adapted to determine the maximum change of speed or velocity v max appearing during a predetermined period of time wliich, in the described embodiment is 30 ms.
  • the discriminator may be adapted to determine speed at a predetermined instant following the initial sensing of an object such as the object 7 by the contact strip 6. This period of time may again be 30 ms.
  • the output of the discriminator 14 is passed to a control circuit 15, the functioning of which will be described in greater detail with reference to Figure 2, but it should be understood at this stage that the contact signal from the contact strip 6 is also passed to the control circuit 15.
  • the control circuit 15 is also connected to receive a signal from a speedometer 16 which indicates the instantaneous speed of the vehicle.
  • the control circuit 15 acts as a signal generator and the output signal of the control circuit 15 is passed to a triggering unit 17 which is adapted to trigger the deployment of a safety device of the general type discussed above, such as a safety device adapted to lift the bonnet or hood of the vehicle.
  • the control circuit 15 is configured to control the triggering unit 17 by utilising predetermined logic.
  • the logic process commences when an object, such as the object 7 is sensed to be in contact with the contact strip 6, as shown at box 20 in Figure 2.
  • the first step in the logic process is to determine the speed or velocity v s as measured by the speedometer 16, and to deteirnine, as shown at box 21, if the instantaneous speed v s is in excess of a predetermined threshold, such as a threshold of 20 km/h. If the speed is less than the threshold, then a positive decision is taken that the triggering unit 17 will not fire, as shown at box 22. At speeds of less than 20km/h the risk of injury to a pedestrian is r nimal, and there is no real advantage in deploying the safety device. Thus, regardless of anything else, if the speed is less than the threshold speed, at the instant of impact with a pedestrian, the triggering unit 17 will not fire to deploy the safety device.
  • a predetermined threshold such as a threshold of 20 km/h.
  • a predetermined reference velocity vi is determined, which is dependent upon the measured speed or velocity speed v s measured at box 23 by the speedometer, and the reference velocity Vi is to be used at a subsequent step in the logic process.
  • the signal from the averaging circuit 10 which averages the outputs of the accelerometer is integrated and discriminated, as described above, and the output v max of the discriminator circuit 14 is used at a subsequent step in the logic process.
  • the width x of the contact strip contacted is compared with a threshold x ⁇ . If the threshold X] is exceeded, then a decision is taken as shown at box 26 not to fire the triggering unit 17, and thus the safety device will not deployed. Thus, if the impact is with a very wide object, such as another vehicle, which has a width greater than the typical width of a pedestrian, then deployment of the safety device is inhibited. However, if the sensed width of the contacted area of the contact strip is less than the threshold xi, then the logic process continues towards the making of a final decision to fire the triggering unit 17 to deploy the safety device.
  • the discriminated value of speed or velocity v max obtained from the discriminator circuit 14 is analysed, and if that discriminated velocity value v raax is greater than a first predetermined fixed reference value v 0 , and less than the reference value ⁇ determined at box 24 in the logic process, then a decision is made to fire the triggering unit 17 to deploy the safety device, as shown at box 28. However, if the discriminated speed or velocity value v max does not meet this criterion, then a decision is taken as shown at box 29 to inhibit firing of the triggering unit 17 and thus the safety device is not deployed. This helps to prevent inappropriate deployment of the safety device in the event of an impact with an object which is more rigid than a pedestrian, such as a bollard, or an object which is not as rigid as a pedestrian, such as a bush.
  • the first predetermined reference value v 0 us selected to be below the value of v max anticipated to arise in all accidents involving frontal impact with a pedestrian at speeds in excess of a selected threshold, such as 20 km/h.
  • v 0 may be selected to be 0.1 m/s.
  • a predetermined reference velocity vi is determined as shown at 24.
  • An appropriate algorithm or formula may be used, or there may be a "look up table”.
  • the reference velocity vi at any specific vehicle speed v s is selected to be between the highest v max that could be anticipated for an accident with a pedestrian and the lowest v max that could be anticipated for an accident involving a fixed object such as a pole, tree or bollard.
  • “comprises” means “includes or consists of and “comprising” means "including or consisting of.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Air Bags (AREA)

Abstract

L'invention concerne un détecteur destiné à un système de sécurité dans un véhicule à moteur conçu afin de détecter un impact entre le pare-chocs (4) du véhicule, et un objet (7) tel qu'un piéton. Le système de détection comprend un capteur, tel que deux accéléromètres (8, 9) qui captent l'accélération du pare-chocs. Le calculateur (10, 11, 12, 13, 14) analyse l'accélération captée afin de déterminer si cette accélération est inférieure à une valeur prédéfinie. Un générateur de signal (15) génère un signal afin de déclencher le dispositif de sécurité si l'accélération est inférieure à la première valeur prédéfinie.
PCT/SE2002/001030 2001-06-02 2002-05-30 Detecteur destine a un systeme de securite WO2002098715A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GBGB0113525.0A GB0113525D0 (en) 2001-06-02 2001-06-02 Improvemnts in or relating to a detector for a safety arrangement
GB0113525.0 2001-06-02
GB0119814A GB2376118B (en) 2001-06-02 2001-08-14 Improvements in or relating to a detector for a safety arrangement
GB0119814.2 2001-08-14

Publications (1)

Publication Number Publication Date
WO2002098715A1 true WO2002098715A1 (fr) 2002-12-12

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ID=26246147

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE2002/001030 WO2002098715A1 (fr) 2001-06-02 2002-05-30 Detecteur destine a un systeme de securite

Country Status (1)

Country Link
WO (1) WO2002098715A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004054850A1 (fr) * 2002-12-17 2004-07-01 Trw Occupant Safety Systems S.P.A. Procede de controle d'ensemble actionneur de capot de vehicule visant a proteger les passants en cas d'impact sur le pare-chocs avant du vehicule
WO2004058545A1 (fr) * 2002-12-31 2004-07-15 Autoliv Development Ab Detecteur d'impact
FR2852565A1 (fr) * 2003-03-19 2004-09-24 Denso Corp Systeme de protection des pietons monte sur vehicule
EP1710598A1 (fr) * 2005-04-07 2006-10-11 Delphi Technologies, Inc. Appareil de détection de la collision d'un véhicule avec un piéton
DE102006035833A1 (de) * 2006-08-01 2007-11-29 Siemens Restraint Systems Gmbh Fußgängerschutzvorrichtung für ein Kraftfahrzeug

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0914992A1 (fr) * 1997-11-05 1999-05-12 Nissan Motor Co., Ltd. Dispositif pour calculer une vitesse et système pour soulever le capot
EP0937612A2 (fr) * 1998-02-24 1999-08-25 Kabushiki Kaisha Toyota Chuo Kenkyusho Appareillage de discrimination d'une collision pour véhicule ayant des éléments de détection dans le pare-chocs avant
DE10045698A1 (de) * 1999-09-16 2001-05-17 Honda Motor Co Ltd Fahrzeughauben-Betriebssystem

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0914992A1 (fr) * 1997-11-05 1999-05-12 Nissan Motor Co., Ltd. Dispositif pour calculer une vitesse et système pour soulever le capot
EP0937612A2 (fr) * 1998-02-24 1999-08-25 Kabushiki Kaisha Toyota Chuo Kenkyusho Appareillage de discrimination d'une collision pour véhicule ayant des éléments de détection dans le pare-chocs avant
DE10045698A1 (de) * 1999-09-16 2001-05-17 Honda Motor Co Ltd Fahrzeughauben-Betriebssystem

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004054850A1 (fr) * 2002-12-17 2004-07-01 Trw Occupant Safety Systems S.P.A. Procede de controle d'ensemble actionneur de capot de vehicule visant a proteger les passants en cas d'impact sur le pare-chocs avant du vehicule
WO2004058545A1 (fr) * 2002-12-31 2004-07-15 Autoliv Development Ab Detecteur d'impact
FR2852565A1 (fr) * 2003-03-19 2004-09-24 Denso Corp Systeme de protection des pietons monte sur vehicule
EP1710598A1 (fr) * 2005-04-07 2006-10-11 Delphi Technologies, Inc. Appareil de détection de la collision d'un véhicule avec un piéton
DE102006035833A1 (de) * 2006-08-01 2007-11-29 Siemens Restraint Systems Gmbh Fußgängerschutzvorrichtung für ein Kraftfahrzeug

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