Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Nippondenso Soken, Inc.

Mitsuhiko Masegi

Akira Kondo

Masao Sakurai

Motoharu Naitou

Toshiaki Ota

Shinichi Kiribayashi

Masahito Mutoh

Motomi Iyoda

Muneaki Matsumoto

Shigeyuki Akita

Minoru Nishida

Koji Numata

Yukiyasu Ueno

Keiji Ito

Koichi Fujita

Nobuo Mayumi

Makoto Aso

Makoto Watanabe

In an activating device for a passenger protection system in a vehicle, erroneous activating operation caused by improper operation of a microcomputer or electrical noise is prevented even though electronic switches are used to operate a squib. A microcomputer has output ports connected to first through third driving circuits controlling first through third electronic switching devices connected in series with a squib for deploying a passenger protection device. A timer circuit is connected to the first switching device by way of a prohibiting circuit provided as a hardware unit independent of the microcomputer.

Activating device for vehicle passenger protection system

A collision-determining device arranged to prevent a passenger protection mechanism from erroneously operating by determining the polar relationship between an acceleration signal indicative of vehicle acceleration and a pseudo signal used to determine whether a vehicle collision has occurred. A G sensor generates the pseudo signal having a polarity opposite from that of a deceleration signal based on a control signal from a microcomputer. An A-D converter receives the pseudo signal via a signal processing circuit and generates a pseudo voltage. The microcomputer determines whether a collision has occurred based on whether the pseudo voltage has been generated and based on the polarity thereof.

Collision-determining circuit for vehicle airbag system with device malfunction monitoring feature

A triggering device for a safety apparatus includes a first detecting section and a second detecting section. The first detection section includes at least one first sensor located in a right-hand portion of a vehicle for detecting a deceleration acting on the vehicle in at least one of a longitudinal direction and a lateral direction of the vehicle. The second detecting section includes at least one second sensor located in a left-hand portion of the vehicle for detecting a deceleration acting on the vehicle in at least one of the longitudinal direction and the lateral direction of the vehicle. A controlling section is operative for triggering the safety apparatus in response to at least two out of detection values related to the longitudinal direction and detection values related to the lateral direction which are generated by the first and second sensors.

Triggering device for safety apparatus

A triggering device for a safety apparatus includes first and second deceleration detecting sensors located within first and second doors of a vehicle respectively or located at positions near the first and second doors respectively. Each of the first and second deceleration detecting sensors is operative for detecting a deceleration. A first signal processing section includes first and second signal processors for processing a detection signal of the first deceleration detecting sensor, and for implementing signal processing with two different processing levels respectively. A second signal processing section includes third and fourth signal processors for processing a detection signal of the second deceleration detecting sensor, and for implementing signal processing with two different processing levels respectively. A first safety device located at the first door is operative for protecting an occupant in the vehicle. A second safety device located at the second door is operative for protecting an occupant in the vehicle. First and second trigger components are operative for triggering the first and second safety devices respectively. One of the first and second trigger components is controlled to trigger one of the first and second safety devices on the basis of results of the signal processing by the first signal processor and the fourth signal processor. The other of the first and second trigger components is controlled to trigger the other of the first and second safety devices on the basis of results of the signal processing by the second signal processor and the third signal processor.

An occupant protection system for an automotive vehicle is provided which includes a pair of squibs for activating a pair of occupant protection units such as an airbag unit and a pretensioner for a seat belt, a backup capacitor, and a switching circuit. The switching circuit serves to allow the electric power stored in the backup capacitor to be supplied to at least one of the occupant protection units upon occurrence of a collision of the vehicle with another object when a sufficient power is not supplied from the power source to the squibs or when a line connected to the power source is broken by the collision of the vehicle.

Occupant protection system for automotive vehicle

A monitor current to a squib as an air bag actuating element conducts in one and the opposite directions alternately. Each produced voltage value is differentially amplified with a positive reference voltage and a difference between the amplified voltages are calculated. Thus, an offset voltage of an operational amplifier used for the differential amplification is cancelled, and the difference between the two detected voltages becomes a voltage value which will be produced by a monitor current twice as large in current level. Thus, the squib is diagnosed accurately.

Failure diagnostic apparatus and method for a resistor element

A passenger protection system for a motor vehicle having a supplementary power supply for operating the protection system has a relatively small capacity. This enables the system to be made more compact and lighter. The vehicle includes a battery disposed in parallel with two diodes via a key switch. Output form one diode charges a back-up condenser. Discharge energy from the back-up condenser is provided to the airbag circuit via a switch. The output of the other diode is also provided to the airbag circuit. The switch is controlled by a detection circuit that judges whether energy is supplied from the back-up condenser to the airbag circuit. An ignition device is set so that the airbag may be operated via a switch which is turned on with deceleration so that the power is provided responsive to a collision determination.

Vehicular passenger protection system

A circuit for controlling the actuation of a vehicle air bag system includes a two terminal electrically actuated ignition element connectable to a drive voltage line through a first transistor and to a circuit ground through another transistor. The voltage source includes the vehicle battery and a capacitor that is charged by the vehicle battery and which supplies operating power in the event the vehicle battery is removed from the circuit, for example, as a consequence of a collision. The transistors are normally biased to a non-conducting state sufficient to isolate the ignition element from the drive voltage source and circuit ground. Vehicle acceleration is sensed by an acceleration sensor which, in the event of a collision, biases both transistors into conduction to effectively connect the two terminals of the ignition element to the drive voltage line and to ground to actuate the vehicle air bag. During normal operation, a bias circuit controls one of the transistors to provide a minute current flow that is used to sense fault conditions and illuminate an alarm lamp. During a collision, the acceleration sensing circuit re-configures the bias circuit to drive both transistors into conduction. A low-voltage circuit senses the drive voltage and controls the bias to the one transistor to inhibit the minute current flow to conserve power during low-voltage conditions.

Releasing circuit for actuating vehicular safety device

Air bags are located at different positions within a vehicle. Squibs serve to fire and activate the air bags respectively. An acceleration detecting device is provided in common to the squibs for detecting an acceleration of the vehicle upon a collision of the vehicle and executing a switching operation in response to the detected vehicle acceleration. Constant-current circuits supplied with an electric power from a vehicle battery feed constant electric currents for a firing operation to the squibs respectively in response to the switching operation of the acceleration detecting device. An energy storage device serves to feed a backup electric power to the constant-current circuits when the supply of the electric power from the vehicle battery is cut off. Each of the constant-current circuits includes a first transistor for feeding an electric current to the related squib, a first resistor for detecting a level of the electric current fed to the squib, a second transistor conducting an electric current with a level which depends on the electric current level detected by the first resistor, and a second resistor for generating a voltage which depends on the electric current conducted by the second transistor and for controlling the first transistor in response to the generated voltage.

Vehicle air bag apparatus

A vehicle operator protection system includes an actuating device, a battery for supplying the actuating device with electric power, and a backup capacitor charged by the battery and supplying power to the actuating device when the battery becomes inoperable. It further includes a switch for cutting off the power supply from the battery and a determining circuit for detecting a discharging condition of the backup capacitor after it has been cut off from the power supply with the switch to determine the existence of an abnormality in the backup capacitor and the actuating device. Through the detection of the discharging condition of the backup capacitor, determination of the existence of an abnormality, based on the intended function of the backup capacitor, can be achieved.

Apparatus and method for determining the existence of an abnormality in

A releasing circuit for actuating a vehicular safety device includes a sensor arranged to provide an acceleration signal responsive to accelerations of the vehicle and an evaluating circuit for setting a predetermined condition for activating a release element of the safety device and responsive to the acceleration signal for effecting the activation of the release element when the predetermined condition has been satisfied by the acceleration signal. A checking circuit for the releasing circuit includes a check signal generator for producing therefrom a check signal at a predetermined level which does not satisfy the predetermined condition and for applying the check signal to a circuit between the sensor and evaluating circuit, a comparator responsive to the check signal for determining as to whether or not there is a defect or malfunction in the circuit between the second and evaluating circuit, and a second comparator responsive to an output signal of the evaluating circuit for ascertaining as to whether or not the release element has been properly activated in response to the acceleration signal under control of the evaluating circuit.

An acceleration sensor detects an acceleration of a vehicle which is caused by a collision of the vehicle. A safety device protects an occupant in the vehicle from the collision of the vehicle. A trigger device triggers the safety device. The trigger device is activated in response to an output signal from the acceleration sensor. An operation of the trigger device is detected and a detection signal representative thereof is generated. A first judgment device judges whether or not the trigger device is activated on the basis of the detection signal. When the trigger device is judged to be activated, a second judgment device judges whether the activation of the trigger device is caused by a correct cause or a false cause on the basis of the output signal from the acceleration sensor. The judgment by the second judgment device is allowed only once and subsequent judgments by the second judgment device are inhibited. A result of the judgment by the second judgment device is recorded.

Apparatus for recording an operating condition of a vehicle safety device

In an apparatus for controlling a headlight of a vehicle, a light from a preceding or oncoming vehicle can be detected without being disturbed by a light reflected on guardrails and the like, or light from a traffic signal, street lights and the like, and the illumination area of the headlight can be suitably adjusted without unnecessary switching of an illumination mode of the headlight. This control is carried out by receiving a light impinging on the front end of the vehicle by a light receiving member divided into a plurality of regions, by carrying out a comparison and discrimination between the light detection signals from the plurality of regions, and based on a result thereof, by selecting an appropriate illumination mode of the headlight.

Apparatus for controlling a headlight of a vehicle

An antitheft system comprises a prohibition device for prohibiting the alarming operation upon receipt of a disarmed memory signal. When an arming signal is inputted, an alarm is generated on the receipt of a theft detection signal generated by handling or operation of vehicle equipment or accessories. When a disarming signal is received, on the other hand, it is sotred and held as the disarmed memory signal in power-supply disconnected state.

Car theft alarm system

A head lamps control system for use on a vehicle for turning on and off the head lamps of the vehicle according to the brightness of the outside of the vehicle, in which a flip flop circuit is set upon closing of an ignition switch and in this set condition it receives power from a DC power source of the vehicle via a fuse to make on-off control for the head lamps in accordance with a signal provided from a photosensor which detects the outside brightness. To the above fuse is connected a load other than this system, and in the event the above fuse opens due to some trouble of such load, power can be fed to this system from a power supply path via the ignition switch, to prevent the head lamps from suddenly going off.

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Aichi, Japan

Mitsuhiko Masegi