WO2005102796A1 - Seat belt warning system - Google Patents

Seat belt warning system Download PDF

Info

Publication number
WO2005102796A1
WO2005102796A1 PCT/EP2005/051667 EP2005051667W WO2005102796A1 WO 2005102796 A1 WO2005102796 A1 WO 2005102796A1 EP 2005051667 W EP2005051667 W EP 2005051667W WO 2005102796 A1 WO2005102796 A1 WO 2005102796A1
Authority
WO
WIPO (PCT)
Prior art keywords
seat belt
seat
acoustic wave
surface acoustic
wave device
Prior art date
Application number
PCT/EP2005/051667
Other languages
French (fr)
Inventor
Laurent Federspiel
Pierre Orlewski
Original Assignee
Iee International Electronics & Engineering S.A.
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
Application filed by Iee International Electronics & Engineering S.A. filed Critical Iee International Electronics & Engineering S.A.
Priority to EP05733477A priority Critical patent/EP1737712B1/en
Priority to DE602005016787T priority patent/DE602005016787D1/en
Priority to US11/578,982 priority patent/US7639125B2/en
Publication of WO2005102796A1 publication Critical patent/WO2005102796A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R22/00—Safety belts or body harnesses in vehicles
    • B60R22/48—Control systems, alarms, or interlock systems, for the correct application of the belt or harness
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
    • B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
    • B60N2/002—Seats provided with an occupancy detection means mounted therein or thereon
    • B60N2/0021—Seats provided with an occupancy detection means mounted therein or thereon characterised by the type of sensor or measurement
    • B60N2/0035—Seats provided with an occupancy detection means mounted therein or thereon characterised by the type of sensor or measurement characterised by the sensor data transmission, e.g. wired connections or wireless transmitters therefor; characterised by the sensor data processing, e.g. seat sensor signal amplification or electric circuits for providing seat sensor information
    • 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
    • B60R21/015—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 the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
    • B60R21/01512—Passenger detection systems
    • 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
    • B60R21/015—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 the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
    • B60R21/01512—Passenger detection systems
    • B60R21/01516—Passenger detection systems using force or pressure 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
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/015—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 the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
    • B60R21/01512—Passenger detection systems
    • B60R21/01516—Passenger detection systems using force or pressure sensing means
    • B60R21/01526—Passenger detection systems using force or pressure sensing means using piezoelectric elements
    • 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
    • B60R21/015—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 the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
    • B60R21/01512—Passenger detection systems
    • B60R21/01544—Passenger detection systems detecting seat belt parameters, e.g. length, tension or height-adjustment
    • B60R21/01546—Passenger detection systems detecting seat belt parameters, e.g. length, tension or height-adjustment using belt buckle sensors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
    • B60N2210/00—Sensor types, e.g. for passenger detection systems or for controlling seats
    • B60N2210/40—Force or pressure sensors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
    • B60N2230/00—Communication or electronic aspects
    • B60N2230/20—Wireless data transmission
    • 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
    • B60R2021/0104—Communication circuits for data transmission
    • B60R2021/01081—Transmission medium
    • B60R2021/01088—Transmission medium wireless
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R22/00—Safety belts or body harnesses in vehicles
    • B60R22/48—Control systems, alarms, or interlock systems, for the correct application of the belt or harness
    • B60R2022/4808—Sensing means arrangements therefor
    • B60R2022/4816—Sensing means arrangements therefor for sensing locking of buckle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R22/00—Safety belts or body harnesses in vehicles
    • B60R22/48—Control systems, alarms, or interlock systems, for the correct application of the belt or harness
    • B60R2022/4808—Sensing means arrangements therefor
    • B60R2022/4858—Sensing means arrangements therefor for sensing pressure on seat

Definitions

  • the present invention relates generally to a seat belt warning system and more specifically to a seat belt reminder system comprising a seat occupancy sensor for detecting an occupancy of a vehicle seat and a seat belt sensor for detecting whether a seat belt is fastened or not.
  • a seat belt reminder system comprising a seat occupancy sensor for detecting an occupancy of a vehicle seat and a seat belt sensor for detecting whether a seat belt is fastened or not.
  • Today's automotive safety standards require automotive vehicles to be equipped with seat belt reminder systems for reminding a vehicle passenger to fasten the seat belt associated to the occupied vehicle seat. While until now, those seat belt reminder systems where mainly associated with the front seats of the vehicle, future standards will require that also rear seat be equipped with such seat belt reminder systems.
  • Seat belt warning systems typically comprise a seat occupancy sensor associated with a vehicle seat for determining the presence of an occupant on the respective seat and for generating a signal indicative of such presence, and a seat belt fastening detector for determining a seat belt usage condition and for generating a signal indicative thereof.
  • a control unit uses the signals of the seat occupancy sensor and the seat belt fastening detector in order to determine whether the actual seat occupancy would require a non-fastened seat belt to be fastened and, if this is the case, to issue a corresponding warning signal.
  • the seat occupancy sensors usually comprise pressure sensing devices integrated in the respective passenger seat for detecting a pressure induced by the presence of a passenger into the seat.
  • the pressure sensing devices as e.g. disclosed in DE-A-4237072, comprise a plurality of individual force sensors, which are connected in a suitable manner to a control unit designed for measuring a pressure depending electrical property of said individual pressure sensors.
  • These occupancy sensors have proven to be very reliable and well adapted to the detection of seat occupancy.
  • the seat belt fastening detectors typically comprises mechanical or magnetic buckle switches for detecting, whether a latch of the seat belt is inserted into the seat belt buckle.
  • One such buckle switch is e.g. disclosed in US Patent US-A-5,871 ,063.
  • seat belt fastening detectors have been proposed which generate a buckled/unbuckled signal based on the tension in the seat belt.
  • the object of the present invention is to provide an improved seat belt warning system, which is suitable for association with removable vehicle seats.
  • the present invention proposes a seat belt warning system comprising a sensing system associated to a vehicle seat for sensing a seat belt related status with respect to said vehicle seat and a control unit communicating with said sensing system for generating a warning signal depending on the seat belt related status deter- mined by said sensing system.
  • the sensing system comprises a seat occupancy detector for determining a seat occupancy status of a vehicle seat and a seat belt fastening detector for determining a seat belt usage condition.
  • said sensing system further comprises a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and in that said control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device.
  • the seat belt warning system comprises a plurality of individual sensing systems, each of said sensing systems being associated to at least one vehicle seat for sensing a seat belt related status with respect to said vehicle seat, and a single control unit com- municating with each sensing system for generating a warning signal depending on the seat belt related status determined by said sensing system.
  • At least one of said sensing systems comprises a seat occupancy detector, a seat belt fastening detector and a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna
  • said single control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device.
  • a surface acoustic wave resonator consists of a piezoelectric substrate with metallic structures (interdigital transducers) on its plain-polished surface. Due to piezoelectricity an electric signal at the interdigital transducers will stimulate a surface acoustic wave on the surface of the substrate. Vice versa a surface acoustic wave generates an electric charge distribution at the receiving interdigital transducers which is measurable as an electric signal. In case of a one port surface acoustic wave resonator only one interdigital transducer is con- nected electrically while the other interdigital transducers are reflective. If the interdigital transducer is connected to an antenna, the element is operable as a passive wirelessly interrogable system.
  • the surface acoustic wave resonator is connected to a miniaturized antenna so that the surface acoustic wave device acts as a resonator. If a radio frequency (RF) signal is sent to the surface acoustic wave device, the surface acoustic wave resonator oscillates at a given frequency and a response signal is wirelessly transmitted back to the control unit.
  • RF radio frequency
  • the present invention uses this remote operability for remotely interrogating the sensing systems associated to the different vehicle seats.
  • the surface acoustic wave device therefore is preferably connected to the seat occupancy sensor or the seat belt fastening detector in such a way, that the resonance frequency of the surface acoustic wave device is modulated depending on the output signals of these detectors.
  • the remote operability of the surface acoustic wave device enables the sensing system, which is integrated into the vehicle seat, to be remotely operated and interrogated without the need for cabling between the sensing system and the control unit.
  • a seat belt related status may be detected for all seats in a car without affecting the flexibility of a seating system with removable and/or displaceable back seats.
  • surface acoustic wave devices are totally passive sensor devices which do not require a dedicated power supply. Thus there is usually no need to provide a battery power for the surface acoustic wave device of the sensing system of the present invention to be operable. Furthermore, surface acoustic wave devices are characterized by their small size, low cost and rigged construction.
  • the seat belt fastening detector preferably comprises a seat belt buckle switch sensor.
  • This seat belt buckle switch sensor is integrated into the seat belt buckle for detecting, whether the latch of the seat belt is inserted into the seat belt buckle.
  • the seat belt buckle itself is typically mounted on the seat and not on the vehicle floor and accordingly the seat belt buckle is removable together with the seat (as is as the seat occupancy sensor). It follows that the seat belt fastening detector and the seat occupancy sensor are both permanently associated with the same seat which avoids conflicts of association between corresponding detectors of different seats.
  • the seat occupancy sensor preferably comprises a pressure sensitive switching device including a plurality of individual pressure sensors or switches arranged at different locations with respect to a seat surface. These pressure sensitive switching devices have proven to be very reliable and well adapted to the detection of seat occupancy.
  • Each of the occupancy sensor and the seat belt sensor could be equipped with an individual surface acoustic wave device and individually communicate with the central control unit.
  • the said seat occupancy sensor and said seat belt fastening detector remotely communicate so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said first surface acoustic wave device. This embodiment reduces the data volume to be transmitted between the sensing system and the control unit.
  • the remote communication between the two components of the sensing system may be achieved if said seat occupancy sensor comprises a second surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and if that seat belt fastening detector comprises an electronic unit including an RF antenna for remotely communicating with said second surface acoustic wave device and for generating said combined occupancy and seat belt signal.
  • the electronic unit of the seat belt fastening detector should be powered in this embodiment in order to emit an interrogation frequency for the second surface acoustic wave device.
  • the electronic unit may therefore be provided with a preferably rechargeable battery for providing the required electrical power.
  • the electronic unit may be connected to a piezo-powered generator associated with a seating surface of the vehicle seat.
  • Such a piezo-powered generator comprises at least one piezoelectric element, which is e.g. integrated into the vehicle seat immediately below the upper seating surface. An occupant sitting in the vehicle seat exerts a varying pressure on the piezoelectric element due to vibrations caused by the vehicle movement, so that the piezo-powered generator generates the required power for the electronic unit.
  • such a piezo-powered generator may also be used if the seat belt buckle sensor needs powering in order to detect the latch inserted into the buckle.
  • said electronic unit is electrically connected to said first surface acoustic wave device so as to activate said first surface acoustic wave device when said combined occupancy and seat belt signal indicates a seat belt warning condition. This means that the surface acoustic wave device is not activated when no warning requiring seat belt status in present. It follows that the central control unit will receive no signal from the surface acoustic wave device and as a consequence, no warning will be issued.
  • the electronic unit may e.g.
  • the electronic unit acts as a switch for establishing an electrical connection between the surface acoustic wave resonator and the antenna. In the absence of a seat belt warning condition, the electronic unit will not close the circuit between the surface acoustic wave resonator and the antenna and the surface acoustic wave device is accordingly not active. Thus the control unit does not receive a signal from the surface acoustic wave device.
  • the electronic unit will be triggered and the electrical contact between the surface acoustic wave resonator and the antenna is established.
  • the control unit thus will receive a response signal from the surface acoustic wave device and may emit a corresponding warning signal.
  • the seat occupancy sensor and said seat belt fastening are interconnected in a combined logic circuit so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said surface acoustic wave device.
  • the combined logic circuit may then be connected to the first surface acoustic wave device so as to activate said first surface acoustic wave device when said combined occupancy and seat belt signal indicates a seat belt warning condition.
  • the combined logic circuit is preferably connected in series between the surface acoustic wave resonator and the antenna of said first surface acoustic wave device.
  • a single control unit may be used for operating and interrogating several sensing systems arranged in different seats of the car.
  • the RF antenna of the control unit may be arranged in a region of the car, where communication is possible with surface acoustic wave devices as well in the front seats as in the rear seats.
  • each of the surface acoustic wave devices associated to the different seats preferably operates in a different oscillating frequency range in order to be selectively addressable.
  • a radio frequency tag may be integrated in each of the surface acoustic wave devices in order to ensure the addressability of each device.
  • each sensing system accordingly comprises at least one identifier means to be detected by said single control unit, wherein the identifier means is preferably integrated into said first surface acoustic wave device.
  • Fig.1 schematically illustrates a vehicle interior compartment with several vehicle seats equipped with an embodiment of a seat belt warning system
  • Fig.2 illustrates the operation mode of one embodiment of the seat belt warning system
  • Fig. 1 schematically illustrates interior compartment of a vehicle 10 with two front seats 12 and three rear seats 14.
  • the front seats 12 and the rear seats 14 are each equipped with a sensing system for sensing a seat belt related status associated to the respective seat.
  • Each sensing system comprises a seat occupancy detector 16 which may consist of a pressure switching element integrated into a seating surface of the respective seat.
  • Each sensing system further comprises a seat belt fastening detector 18, which may comprise a buckle switch sensor integrated into the seat belt buckle associated with the seat.
  • a central control unit 20 is mounted in a suitable location in the vehicle com- partment.
  • the central control unit is connected to a centrally located RF antenna 22 via interface 24.
  • the central RF antenna is configured for remotely communicating with the sensing systems arranged in the different seats and for obtaining said seat belt related status from said sensing systems.
  • each sensing system is preferably equipped with a surface acoustic wave device 26 (see also fig. 2) including at least one surface acoustic wave resonator 26' and an antenna 26".
  • the surface acoustic wave device 26 is e.g. integrated into the seat belt buckle for communication with the buckle switch sensor.
  • the seat occupancy sensor 16 and the seat belt fastening detector 18 may also communicate (via respective connection lines or via RF) so as to provide a combined occupancy and seat belt signal.
  • the seat occupancy sensor 16 and the seat belt fastening detector 18 are associated to the surface acoustic wave device 26 so as to alter the resonance frequency of the surface acoustic wave device 26 depending on the combined occupancy and seat belt signal.
  • the central control unit 20 periodically or permanently emits an excitation frequency RF 0 via antenna 22 located e.g. in the vehicle roof. This excitation frequency RF 0 is received by the surface acoustic wave devices 26 and causes the surface acoustic wave resonator to oscillate with a frequency RFi or RF 2 , which is depending on the combined occupancy and seat belt signal.
  • This resonant frequency is subsequently received by antenna 22 and detected by central control unit 20.
  • the combined occupancy and seat belt signal is accordingly transmitted to the control unit 20 by means of the surface acous- tic wave device 26.
  • the control unit 20 If the received frequency RF corresponds to a predetermined seat belt warning condition (e.g. seat occupied and seat belt unbuckled), the control unit 20 will subsequently issue a corresponding warning signal (audible, optical, tactile, etc.) 8see upper part of fig. 2). If however no predetermined seat belt warning condition is present (e.g. seat occupied and belt buckled or seat unoccupied) the control unit will receive a signal with a frequency RFi indicative of this condition and no alarm will be issued (lower part of fig. 2). It will be noted that each surface acoustic wave device 26 is preferably provided
  • each surface acoustic wave device will be safely identifiable and control unit 20 may correctly identify from which seat a specific signal emanates.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Transportation (AREA)
  • Automation & Control Theory (AREA)
  • Automotive Seat Belt Assembly (AREA)

Abstract

A seat belt warning system comprises a sensing system associated to a vehicle seat for sensing a seat belt related status with respect to said vehicle seat and a control unit communicating with said sensing system for generating a warning signal depending on the seat belt related status determined by said sensing system. The sensing system comprises a seat occupancy detector (16) for determining a seat occupancy status of a vehicle seat and a seat belt fastening detector (18) for determining a seat belt usage condition. According to the invention said sensing system further comprises a first surface acoustic wave device (26) including at least one surface acoustic wave resonator (26’) and an antenna (26’’) and in that said control unit (20) comprises an RF antenna (22) for remotely communicating with said surface acoustic wave device (26).

Description

Seat Belt Warning System
Introduction
The present invention relates generally to a seat belt warning system and more specifically to a seat belt reminder system comprising a seat occupancy sensor for detecting an occupancy of a vehicle seat and a seat belt sensor for detecting whether a seat belt is fastened or not. Today's automotive safety standards require automotive vehicles to be equipped with seat belt reminder systems for reminding a vehicle passenger to fasten the seat belt associated to the occupied vehicle seat. While until now, those seat belt reminder systems where mainly associated with the front seats of the vehicle, future standards will require that also rear seat be equipped with such seat belt reminder systems.
Seat belt warning systems typically comprise a seat occupancy sensor associated with a vehicle seat for determining the presence of an occupant on the respective seat and for generating a signal indicative of such presence, and a seat belt fastening detector for determining a seat belt usage condition and for generating a signal indicative thereof. A control unit then uses the signals of the seat occupancy sensor and the seat belt fastening detector in order to determine whether the actual seat occupancy would require a non-fastened seat belt to be fastened and, if this is the case, to issue a corresponding warning signal.
The seat occupancy sensors usually comprise pressure sensing devices integrated in the respective passenger seat for detecting a pressure induced by the presence of a passenger into the seat. The pressure sensing devices, as e.g. disclosed in DE-A-4237072, comprise a plurality of individual force sensors, which are connected in a suitable manner to a control unit designed for measuring a pressure depending electrical property of said individual pressure sensors. These occupancy sensors have proven to be very reliable and well adapted to the detection of seat occupancy. The seat belt fastening detectors typically comprises mechanical or magnetic buckle switches for detecting, whether a latch of the seat belt is inserted into the seat belt buckle. One such buckle switch is e.g. disclosed in US Patent US-A-5,871 ,063. As an alternative to the buckle switches, seat belt fastening detectors have been proposed which generate a buckled/unbuckled signal based on the tension in the seat belt.
One drawback of the known seat belt warning systems lies in the fact, that the seat occupancy sensor and the seat belt fastening detector have to be physically connected to the control unit by means of connection wires in order to be functional. This need for physically connecting the sensing device to the control unit however causes problems especially in modern cars equipped with a flexible seating system with removable and/or displaceable back seats.
Object of the invention
The object of the present invention is to provide an improved seat belt warning system, which is suitable for association with removable vehicle seats.
General description of the invention
In order to overcome the abovementioned problems, the present invention proposes a seat belt warning system comprising a sensing system associated to a vehicle seat for sensing a seat belt related status with respect to said vehicle seat and a control unit communicating with said sensing system for generating a warning signal depending on the seat belt related status deter- mined by said sensing system. The sensing system comprises a seat occupancy detector for determining a seat occupancy status of a vehicle seat and a seat belt fastening detector for determining a seat belt usage condition. According to the invention said sensing system further comprises a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and in that said control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device. In a preferred embodiment of the invention, the seat belt warning system comprises a plurality of individual sensing systems, each of said sensing systems being associated to at least one vehicle seat for sensing a seat belt related status with respect to said vehicle seat, and a single control unit com- municating with each sensing system for generating a warning signal depending on the seat belt related status determined by said sensing system. In this embodiment at least one of said sensing systems comprises a seat occupancy detector, a seat belt fastening detector and a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna, while said single control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device. It follows that in this embodiment, the different individual sensing systems are interfaced with one single control unit.
A surface acoustic wave resonator consists of a piezoelectric substrate with metallic structures (interdigital transducers) on its plain-polished surface. Due to piezoelectricity an electric signal at the interdigital transducers will stimulate a surface acoustic wave on the surface of the substrate. Vice versa a surface acoustic wave generates an electric charge distribution at the receiving interdigital transducers which is measurable as an electric signal. In case of a one port surface acoustic wave resonator only one interdigital transducer is con- nected electrically while the other interdigital transducers are reflective. If the interdigital transducer is connected to an antenna, the element is operable as a passive wirelessly interrogable system.
The surface acoustic wave resonator is connected to a miniaturized antenna so that the surface acoustic wave device acts as a resonator. If a radio frequency (RF) signal is sent to the surface acoustic wave device, the surface acoustic wave resonator oscillates at a given frequency and a response signal is wirelessly transmitted back to the control unit. The present invention uses this remote operability for remotely interrogating the sensing systems associated to the different vehicle seats. The surface acoustic wave device therefore is preferably connected to the seat occupancy sensor or the seat belt fastening detector in such a way, that the resonance frequency of the surface acoustic wave device is modulated depending on the output signals of these detectors. The remote operability of the surface acoustic wave device enables the sensing system, which is integrated into the vehicle seat, to be remotely operated and interrogated without the need for cabling between the sensing system and the control unit. Thus a seat belt related status may be detected for all seats in a car without affecting the flexibility of a seating system with removable and/or displaceable back seats.
It will be noted that surface acoustic wave devices are totally passive sensor devices which do not require a dedicated power supply. Thus there is usually no need to provide a battery power for the surface acoustic wave device of the sensing system of the present invention to be operable. Furthermore, surface acoustic wave devices are characterized by their small size, low cost and rigged construction.
It will further be appreciated, that the seat belt fastening detector preferably comprises a seat belt buckle switch sensor. This seat belt buckle switch sensor is integrated into the seat belt buckle for detecting, whether the latch of the seat belt is inserted into the seat belt buckle. The seat belt buckle itself is typically mounted on the seat and not on the vehicle floor and accordingly the seat belt buckle is removable together with the seat (as is as the seat occupancy sensor). It follows that the seat belt fastening detector and the seat occupancy sensor are both permanently associated with the same seat which avoids conflicts of association between corresponding detectors of different seats.
The seat occupancy sensor preferably comprises a pressure sensitive switching device including a plurality of individual pressure sensors or switches arranged at different locations with respect to a seat surface. These pressure sensitive switching devices have proven to be very reliable and well adapted to the detection of seat occupancy.
Each of the occupancy sensor and the seat belt sensor could be equipped with an individual surface acoustic wave device and individually communicate with the central control unit. In a preferred embodiment however, the said seat occupancy sensor and said seat belt fastening detector remotely communicate so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said first surface acoustic wave device. This embodiment reduces the data volume to be transmitted between the sensing system and the control unit.
The remote communication between the two components of the sensing system may be achieved if said seat occupancy sensor comprises a second surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and if that seat belt fastening detector comprises an electronic unit including an RF antenna for remotely communicating with said second surface acoustic wave device and for generating said combined occupancy and seat belt signal. It will be noted, that the electronic unit of the seat belt fastening detector should be powered in this embodiment in order to emit an interrogation frequency for the second surface acoustic wave device. The electronic unit may therefore be provided with a preferably rechargeable battery for providing the required electrical power. Alternatively the electronic unit may be connected to a piezo-powered generator associated with a seating surface of the vehicle seat. Such a piezo-powered generator comprises at least one piezoelectric element, which is e.g. integrated into the vehicle seat immediately below the upper seating surface. An occupant sitting in the vehicle seat exerts a varying pressure on the piezoelectric element due to vibrations caused by the vehicle movement, so that the piezo-powered generator generates the required power for the electronic unit.
It will be appreciated that such a piezo-powered generator may also be used if the seat belt buckle sensor needs powering in order to detect the latch inserted into the buckle. In an advantageous embodiment of the invention said electronic unit is electrically connected to said first surface acoustic wave device so as to activate said first surface acoustic wave device when said combined occupancy and seat belt signal indicates a seat belt warning condition. This means that the surface acoustic wave device is not activated when no warning requiring seat belt status in present. It follows that the central control unit will receive no signal from the surface acoustic wave device and as a consequence, no warning will be issued. The electronic unit may e.g. be connected in series between the surface acoustic wave resonator and the antenna of said first surface acoustic wave device so as to close a respective surface acoustic wave device circuit when a seat belt warning condition is present. It follows that the electronic unit acts as a switch for establishing an electrical connection between the surface acoustic wave resonator and the antenna. In the absence of a seat belt warning condition, the electronic unit will not close the circuit between the surface acoustic wave resonator and the antenna and the surface acoustic wave device is accordingly not active. Thus the control unit does not receive a signal from the surface acoustic wave device. If however a seat belt warning condition is present, the electronic unit will be triggered and the electrical contact between the surface acoustic wave resonator and the antenna is established. The control unit thus will receive a response signal from the surface acoustic wave device and may emit a corresponding warning signal. In an alternative embodiment, the seat occupancy sensor and said seat belt fastening are interconnected in a combined logic circuit so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said surface acoustic wave device. The combined logic circuit may then be connected to the first surface acoustic wave device so as to activate said first surface acoustic wave device when said combined occupancy and seat belt signal indicates a seat belt warning condition. As in the previously described embodiment, the combined logic circuit is preferably connected in series between the surface acoustic wave resonator and the antenna of said first surface acoustic wave device.
It will be noted, that a single control unit may be used for operating and interrogating several sensing systems arranged in different seats of the car. In a possible embodiment, the RF antenna of the control unit may be arranged in a region of the car, where communication is possible with surface acoustic wave devices as well in the front seats as in the rear seats. It will be appreciated that in this case each of the surface acoustic wave devices associated to the different seats preferably operates in a different oscillating frequency range in order to be selectively addressable. Alternatively or additionally a radio frequency tag may be integrated in each of the surface acoustic wave devices in order to ensure the addressability of each device. In this embodiment, each sensing system accordingly comprises at least one identifier means to be detected by said single control unit, wherein the identifier means is preferably integrated into said first surface acoustic wave device.
Detailed description with respect to the figures
The present invention will be more apparent from the following description of several not limiting embodiments with reference to the attached drawings, wherein Fig.1 : schematically illustrates a vehicle interior compartment with several vehicle seats equipped with an embodiment of a seat belt warning system; Fig.2: illustrates the operation mode of one embodiment of the seat belt warning system. Fig. 1 schematically illustrates interior compartment of a vehicle 10 with two front seats 12 and three rear seats 14. The front seats 12 and the rear seats 14 are each equipped with a sensing system for sensing a seat belt related status associated to the respective seat. Each sensing system comprises a seat occupancy detector 16 which may consist of a pressure switching element integrated into a seating surface of the respective seat. Each sensing system further comprises a seat belt fastening detector 18, which may comprise a buckle switch sensor integrated into the seat belt buckle associated with the seat.
A central control unit 20 is mounted in a suitable location in the vehicle com- partment. The central control unit is connected to a centrally located RF antenna 22 via interface 24. The central RF antenna is configured for remotely communicating with the sensing systems arranged in the different seats and for obtaining said seat belt related status from said sensing systems. In order to achieve such remote communication, each sensing system is preferably equipped with a surface acoustic wave device 26 (see also fig. 2) including at least one surface acoustic wave resonator 26' and an antenna 26". The surface acoustic wave device 26 is e.g. integrated into the seat belt buckle for communication with the buckle switch sensor. The seat occupancy sensor 16 and the seat belt fastening detector 18 may also communicate (via respective connection lines or via RF) so as to provide a combined occupancy and seat belt signal. The seat occupancy sensor 16 and the seat belt fastening detector 18 are associated to the surface acoustic wave device 26 so as to alter the resonance frequency of the surface acoustic wave device 26 depending on the combined occupancy and seat belt signal. The central control unit 20 periodically or permanently emits an excitation frequency RF0 via antenna 22 located e.g. in the vehicle roof. This excitation frequency RF0 is received by the surface acoustic wave devices 26 and causes the surface acoustic wave resonator to oscillate with a frequency RFi or RF2, which is depending on the combined occupancy and seat belt signal. This resonant frequency is subsequently received by antenna 22 and detected by central control unit 20. In this way, the combined occupancy and seat belt signal is accordingly transmitted to the control unit 20 by means of the surface acous- tic wave device 26. If the received frequency RF corresponds to a predetermined seat belt warning condition (e.g. seat occupied and seat belt unbuckled), the control unit 20 will subsequently issue a corresponding warning signal (audible, optical, tactile, etc.) 8see upper part of fig. 2). If however no predetermined seat belt warning condition is present (e.g. seat occupied and belt buckled or seat unoccupied) the control unit will receive a signal with a frequency RFi indicative of this condition and no alarm will be issued (lower part of fig. 2). It will be noted that each surface acoustic wave device 26 is preferably provided
' with an RF tag 28 enabling a safe identification of the respective surface acoustic wave device 26. As a result, the resonant frequency of each surface acoustic wave device will be safely identifiable and control unit 20 may correctly identify from which seat a specific signal emanates.
Listing of reference numerals
10 vehicle 12 front seats 14 rear seats
16 seat occupancy detector 18 seat belt fastening detector 20 central control unit 22 RF antenna 24 interface
26 surface acoustic wave device 28 RF tag

Claims

Claims
1. Seat belt warning system comprising a sensing system associated to a vehicle seat for sensing a seat belt related status with respect to said vehicle seat and a control unit communicating with said sensing system for generating a warning signal depending on the seat belt related status de- termined by said sensing system, wherein said sensing system comprises a seat occupancy detector for determining a seat occupancy status of a vehicle seat and a seat belt fastening detector for determining a seat belt usage condition, characterised in that said sensing system further comprises a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and in that said control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device.
2. Seat belt warning system comprising a plurality of individual sensing systems, each of said sensing systems being associated to at least one vehicle seat for sensing a seat belt related status with respect to said vehi- cle seat, and a single control unit communicating with each sensing system for generating a warning signal depending on the seat belt related status determined by said sensing system, wherein at least one of said sensing systems comprises a seat occupancy detector for determining a seat occupancy status of a vehicle seat and a seat belt fastening detector for deter- mining a seat belt usage condition, characterised in that said at least one sensing system further comprises a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and in that said single control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device.
3. Seat belt warning system according to any one of claims 1 or 2, wherein said seat occupancy sensor and said seat belt fastening detector remotely communicate so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said first surface acoustic wave device.
4. Seat belt warning system according to claim 3, wherein said seat occupancy sensor comprises a second surface acoustic wave device including at least one surface acoustic wave resonator and an antenna and in that seat belt fastening detector comprises an electronic unit including an RF antenna for remotely communicating with said second surface acoustic wave device and for generating said combined occupancy and seat belt signal.
5. Seat belt warning system according to claim 4, wherein said electronic unit is electrically connected to said first surface acoustic wave device so as to activate said first surface acoustic wave device when said combined occupancy and seat belt signal indicates a seat belt warning condition.
6. Seat belt warning system according to claim 5, wherein said electronic unit is connected in series between the surface acoustic wave resonator and the antenna of said first surface acoustic wave device.
7. Seat belt warning system according to any one of claims 1 or 2, wherein said seat occupancy sensor and said seat belt fastening are interconnected in a combined logic circuit so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said surface acoustic wave device.
8. Seat belt warning system according to claim 7, wherein said combined logic circuit is electrically connected to said first surface acoustic wave device so as to activate said first surface acoustic wave device when said combined occupancy and seat belt signal indicates a seat belt warning condition.
9. Seat belt warning system according to claim 8, wherein said combined logic circuit is connected in series between the surface acoustic wave resonator and the antenna of said first surface acoustic wave device.
10. Seat belt warning system according to any one of claims 1 to 5, wherein said sensing system comprises at least one identifier means to be detected by said single control unit.
11. Seat belt warning system according to claim 6, wherein said at least one identifier means is integrated into said first surface acoustic wave device.
12. Seat belt warning system according to any one of claims 1 to 11 , wherein said seat belt fastening detector comprises a seat belt buckle switch sensor.
13. Seat belt warning system according to any one of claims 1 to 12, wherein said seat occupancy sensor comprises pressure sensitive switching device comprising a plurality of individual pressure sensors or switches arranged at different locations with respect to a seat surface.
PCT/EP2005/051667 2004-04-22 2005-04-15 Seat belt warning system WO2005102796A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP05733477A EP1737712B1 (en) 2004-04-22 2005-04-15 Seat belt warning system
DE602005016787T DE602005016787D1 (en) 2004-04-22 2005-04-15 SEAT BELT WARNING SYSTEM
US11/578,982 US7639125B2 (en) 2004-04-22 2005-04-15 Seat belt warning system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP04101684.1 2004-04-22
EP04101684A EP1588908A1 (en) 2004-04-22 2004-04-22 Seat belt warning system

Publications (1)

Publication Number Publication Date
WO2005102796A1 true WO2005102796A1 (en) 2005-11-03

Family

ID=34928994

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2005/051667 WO2005102796A1 (en) 2004-04-22 2005-04-15 Seat belt warning system

Country Status (4)

Country Link
US (1) US7639125B2 (en)
EP (2) EP1588908A1 (en)
DE (1) DE602005016787D1 (en)
WO (1) WO2005102796A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1775174A1 (en) * 2005-10-12 2007-04-18 Elesys North America Inc. Occupant sensor and method for seat belt or other monitoring
FR2929213A1 (en) * 2008-03-31 2009-10-02 Innovative & Emerging Europ Ma Individual e.g. infant, transporting safety-device for automobile seat, has control system comprising algorithmic process to provide remote control for holding system and for locking and/or unlocking seat buckle assembled in same volume

Families Citing this family (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7163263B1 (en) 2002-07-25 2007-01-16 Herman Miller, Inc. Office components, seating structures, methods of using seating structures, and systems of seating structures
US20070182535A1 (en) * 2006-02-09 2007-08-09 Alps Automotive, Inc. Wireless sourceless sensor
DE102006042455A1 (en) * 2006-02-21 2007-08-23 Volkswagen Ag Seat belt buckle for motor vehicle, has guide seat belt, which is loaded mechanically by seat belt buckle and in pushing condition of guide is detected by switch
FR2902392B1 (en) 2006-06-15 2008-09-19 Peugeot Citroen Automobiles Sa SYSTEM FOR DETECTING BELT CLOSURE IN A MOTOR VEHICLE
US20080088426A1 (en) * 2006-10-13 2008-04-17 Blair Lima Baby chime
DE102007060317B4 (en) 2007-04-27 2010-09-16 Johnson Controls Gmbh Method and device for monitoring vehicle occupants
US7896391B2 (en) * 2007-08-27 2011-03-01 Lear Corporation Method and system for detecting seat position
US7813856B2 (en) * 2007-10-03 2010-10-12 Gm Global Technology Operations, Inc. Vehicular seatbelt monitoring system and process
DE102007055091A1 (en) * 2007-11-16 2009-05-20 Airbus Deutschland Gmbh Seat arrangement in an aircraft
US8005595B2 (en) * 2007-11-20 2011-08-23 Tk Holdings Inc. Occupant monitoring and restraint status system
US8217770B2 (en) * 2007-12-12 2012-07-10 Tk Holdings Inc. Seat belt system
US8090504B2 (en) * 2008-01-09 2012-01-03 International Business Machines Corporation Feedback loop system for passenger safety
US8577711B2 (en) * 2008-01-25 2013-11-05 Herman Miller, Inc. Occupancy analysis
US20100013622A1 (en) * 2008-07-18 2010-01-21 Tk Holdings Inc. Adaptive light seatbelt buckle
EP2189372B1 (en) * 2008-11-21 2012-06-13 Deutsche Telekom AG Method and system for passenger seat belt verification
JP5116815B2 (en) * 2009-10-20 2013-01-09 藤井電工株式会社 Safety belt and its usage confirmation system
DE102010010613A1 (en) * 2010-03-08 2011-09-08 Volkswagen Ag Vehicle with a safety belt system
US20130300555A1 (en) * 2012-05-09 2013-11-14 Delphi Technologies, Inc. Seat belt reminder system
US9120396B2 (en) 2013-01-11 2015-09-01 Tk Holdings Inc. Occupant classification system with seat back sensor
US9778263B2 (en) 2013-11-13 2017-10-03 General Electric Company Quantitative in situ characterization of biological samples
JP6049081B2 (en) * 2013-11-28 2016-12-21 アルプス電気株式会社 Seat belt attachment / detachment detector
KR20170005805A (en) * 2014-04-10 2017-01-16 로크리브 홀딩스 피티와이. 리미티드 Monitoring and alert system and method for latching mechanisms
CN107709087A (en) * 2015-06-05 2018-02-16 Iee国际电子工程股份公司 Suitable for the wireless vehicle seat sensor unit of removable seat
US9847009B2 (en) * 2015-09-26 2017-12-19 Toyota Motor Engineering & Manufacturing North America, Inc. Connection confirmation using acoustic data
LU93261B1 (en) 2016-10-13 2018-04-17 Iee Sa Seat Belt Status Monitoring System
US10330813B2 (en) 2017-07-11 2019-06-25 Joyson Safety Systems Acquisition Llc Occupant detection system
WO2019075403A1 (en) 2017-10-12 2019-04-18 General Electric Company Prognostic characterization of biological sample
JP7055686B2 (en) * 2018-04-09 2022-04-18 矢崎総業株式会社 Vehicle detectors and vehicle detection systems
US11318910B2 (en) 2018-05-08 2022-05-03 Freedman Seating Company Vehicle passenger sensing and reporting system
US10457208B1 (en) * 2018-05-08 2019-10-29 Freedman Seating Company Vehicle passenger sensing and reporting system
US20200094761A1 (en) * 2018-09-24 2020-03-26 Novelic D.O.O. Seat occupation, vital signs and safety belt lock sensor system for rear vehicle seats without power supply
US11465746B2 (en) * 2020-02-17 2022-10-11 Jeff Johnson Method and apparatus for detecting seatbelt compliance in commercial passenger aircraft
US11145178B1 (en) * 2020-04-21 2021-10-12 Linda Marie Jones Passenger reminder system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3874474A (en) * 1973-11-12 1975-04-01 Lectron Products Method and apparatus for detecting the utilization of a vehicle safety belt
US4885566A (en) * 1986-12-22 1989-12-05 Aisin Seiki Kabushiki Kaisha Apparatus for detecting the wearing of a seat belt assembly
US20040066287A1 (en) * 2002-10-03 2004-04-08 Breed David S. Apparatus for boosting signals from a signal-generating device
US20040069075A1 (en) * 2001-09-12 2004-04-15 Bernhard Jakoby Sensor for recognition of seat occupancy

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0061033B1 (en) * 1981-03-06 1985-10-30 Matsushita Electric Industrial Co., Ltd. Electrostatic voltage sensor
DE4237072C1 (en) 1992-11-03 1993-12-02 Daimler Benz Ag Resistive film pressure or force sensor for indicating occupation of vehicle seat - has conductive paths for providing series of meandering interdigitated local area transducer electrodes on polymer and semiconductor substrate.
US5871063A (en) * 1997-01-22 1999-02-16 Automotive Systems Laboratory, Inc. Seat belt latch sensor system
AUPQ194699A0 (en) * 1999-07-30 1999-08-26 Phoenix Ventures Pty Ltd Harness safety alarm

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3874474A (en) * 1973-11-12 1975-04-01 Lectron Products Method and apparatus for detecting the utilization of a vehicle safety belt
US4885566A (en) * 1986-12-22 1989-12-05 Aisin Seiki Kabushiki Kaisha Apparatus for detecting the wearing of a seat belt assembly
US20040069075A1 (en) * 2001-09-12 2004-04-15 Bernhard Jakoby Sensor for recognition of seat occupancy
US20040066287A1 (en) * 2002-10-03 2004-04-08 Breed David S. Apparatus for boosting signals from a signal-generating device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1775174A1 (en) * 2005-10-12 2007-04-18 Elesys North America Inc. Occupant sensor and method for seat belt or other monitoring
EP1839962A1 (en) * 2005-10-12 2007-10-03 Elesys North America Inc. Occupant sensor and method for seat belt or other monitoring
US7830246B2 (en) 2005-10-12 2010-11-09 Elesys North America, Inc. Occupant sensor and method for seat belt or other monitoring
FR2929213A1 (en) * 2008-03-31 2009-10-02 Innovative & Emerging Europ Ma Individual e.g. infant, transporting safety-device for automobile seat, has control system comprising algorithmic process to provide remote control for holding system and for locking and/or unlocking seat buckle assembled in same volume

Also Published As

Publication number Publication date
EP1588908A1 (en) 2005-10-26
DE602005016787D1 (en) 2009-11-05
US7639125B2 (en) 2009-12-29
EP1737712B1 (en) 2009-09-23
EP1737712A1 (en) 2007-01-03
US20070205884A1 (en) 2007-09-06

Similar Documents

Publication Publication Date Title
US7639125B2 (en) Seat belt warning system
US8041482B2 (en) Seat sensor system
US7762583B2 (en) Seat sensor system
US7560827B2 (en) Removable seat sensing system
US7813856B2 (en) Vehicular seatbelt monitoring system and process
US6998988B1 (en) Infant alarm system for an automobile
KR0165703B1 (en) Method and apparatus for sensing a rearward facing child seat
US7642907B2 (en) Wireless buckle-up detection using RF technology
US8902057B2 (en) Belt buckle for a motor vehicle
US20080309493A1 (en) Wireless system to detect presence of child in a baby car seat
US6868734B2 (en) Sensor for recognition of seat occupancy
US8013727B2 (en) Device for detecting vehicle seat occupancy
US20190232909A1 (en) Seat belt status monitoring system
US20060283651A1 (en) Vehicle passenger detection apparatus with wireless acquisition of passenger-related data
SE510164C2 (en) Seat belt assembly and procedure
US7536920B2 (en) Seat occupancy detector
CN101022979A (en) Seat sensor system
EP1669249A1 (en) Seat belt warning system for a vehicle
JP4171548B2 (en) Seat belt wearing detector
JP2007512175A (en) Collision sensor for automobile bumper

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

DPEN Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed from 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2005733477

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 11578982

Country of ref document: US

Ref document number: 2007205884

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Ref document number: DE

WWP Wipo information: published in national office

Ref document number: 2005733477

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 11578982

Country of ref document: US