Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Nippondenso Co., Ltd.

Takao Akatsuka

Jiro Nakano

Takahide Kawamura

Takao Ishibashi

Shigekatsu Uchida

Masao Kawaguchi

Hiromichi Fujishima

Motomi Iyoda

Masachika Kamiya

Koichi Fujita

Koichi Sugiyama

Koji Iwamoto

Mamoru Takata

Satoshi Ishii

Tomokazu Sakaguchi

Nobuyuki Kobayashi

Hideo Miyagi

Masakazu Ninomiya

Toshimitsu Ito

Masaomi Nagase

Yasumichi Hotta

Michihiro Yamakawa

Manabu Mizutani

Motoshi Kondo

A structure and method for enabling a passive vehicle occupant restraint to be activated at the earliest possible timing, irrespective of a type of a collision. A floor sensor measures a deceleration G applied to the length of a vehicle and outputs the deceleration as the measurement G. An arithmetic unit carries out a predetermined arithmetic operation on the measurement G output from the floor sensor, so as to determine a function f(G). A conditional activation unit has a variation pattern of a threshold value T that varies with a variation in velocity v of a non-stationary object. The conditional activation unit reads a threshold value T corresponding to an input velocity v from the variation pattern and compares the threshold value T with the value of the function f(G). In case that the value of the function f(G) exceeds the threshold value T, an activation signal A is input to a driving circuit. A satellite sensor outputs an ON signal when a deceleration of not less than a predetermined reference value is applied to the vehicle. A threshold variation pattern selection unit changes the variation pattern of the threshold value T against the velocity v used in the conditional activation unit to another variation pattern, in response to the ON signal output from the satellite sensor.

Activation control apparatus for passive vehicle occupant restraint and method of controlling activation of passive vehicle occupant restraint

An activating apparatus of passive safety device having squibs, each for activating a passive safety device for protecting a passenger, current controllers for controlling an electric current supplied from an on-vehicle power supply to the squibs in the event of a crash and for controlling an electric current supplied from an off-vehicle power supply that is connected at the time of disposal of the passive safety devices, to the squibs, and a driver for outputting a driving signal to the current controllers to supply the electric current from the on-vehicle power supply or the off-vehicle power supply to the squibs, thereby activating the passive safety devices. The driver disables outputting of the driving signal based on the crash to the current controllers at the time of disposal of the passive safety devices.

Apparatus for activating passive safety device

A floor sensor,measures a deceleration G applied to the length of a vehicle and outputs the deceleration as the measurement G. An arithmetic unit,carries out a predetermined arithmetic operation on the measurement G output from the floor sensor,, so as to determine a function f(G). A conditional activation unit,has a variation pattern of a threshold value T that varies with a variation in velocity v of a non-stationary object. The conditional activation unit,reads a threshold value T corresponding to an input velocity v from the variation pattern and compares the threshold value T with the value of the function f(G). In case that the value of the function f(G) exceeds the threshold value T, an activation signal A is input to a driving circuit,. A satellite sensor 30 outputs an ON signal when a deceleration of not less than a predetermined reference value is applied to the vehicle. A threshold variation pattern changing unit,changes the variation pattern of the threshold value T against the velocity v used in the conditional activation unit,to another variation pattern, in response to the ON signal output from the satellite sensor,. This structure of the present invention enables a passive vehicle occupant restraint to be activated at the earliest possible timing, irrespective of a type of a collision, in which the vehicle crashes.

Display system of a theft preventing apparatus having two kinds of theft

Vehicle anti-theft system and method using switching device provided in

A diagnosing apparatus for use in a vehicle is disclosed. A microcomputer operates according to either a first mode or a second mode. The second mode being used for the diagnosis requiring a higher precision than the diagnosis according to the first mode. A first program for detecting the malfunction of a control system and a second program having a higher detection precision than the first program is stored in a memory. The operation mode of the microcomputer is selected in accordance with an extent of the malfunction. The diagnosis according to the first program and the second program are executed when the first mode and the second mode are selected, respectively. An operation status of the control system is detected by sensors the diagnosis is performed in the second mode. The diagnosis mode is forcibly returned to the first mode from the second mode when the status detected by the detecting means matches with a predetermined conditions.

Diagnosis apparatus for vehicle control system

A plurality of air-fuel ratio sensors having a temperature characteristic are disposed in an exhaust passage in an engine, with heaters respectively provided in the sensors. The heaters generate heat when energized. An electronic control unit controls the energization of each heater in accordance with the driving conditions of the engine and the temperature condition of the exhaust passage, thereby controlling the amount of generated heat of each heater. As a result, the temperature of each sensor is controlled. When driving conditions allow an interruption to the energization of the individual heaters, the electronic control unit forcibly stops the energization of all the heaters for a predetermined period of time regardless of the energizing status of each heater. Thereafter, the electronic control unit restarts the energization of the heaters one after another, compares the value of the current flowing through each heater in the energizing state with a reference value, and determines the deterioration of the performance of each heater based on the comparison result.

Failure detecting apparatus in temperature controller of air-fuel ratio

An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating the sensor element. A method is disclosed for controlling the power supplied to the heater by determining a target value therefor according to engine operational parameters, by applying a smoothing correction to the target value to produce an actual value, and by supplying power to the heater in an amount according to this actual power value. The smoothing may be done by time-smoothing, and may be done by performing the calculation repeatedly in a cycle and by setting the actual power value amount equal to a function of this target power value and of values of this actual power value amount determined in previous cycles. This function may take the form of a weighted average, and as a special case such a weighted average may use only the actual power value amount determined in the previous cycle. Accordingly it is ensured that the heater is properly operated even in the case of quick variation in the engine operational parameters, which due to system inertia will only alter the exhaust gas temperature with a certain time lag. Thus, the oxygen sensor is properly kept heated up, even in such quick engine operational state alteration conditions, and engine performance and the quality of exhaust gas emissions at such a time are ensured to be good. A system is also described for implementing this method.

Method and system for internal combustion engine oxygen sensor heating

An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating the sensor element. A method for controlling the electrical power supplied to the heater properly and quickly heats up the sensor element after engine starting from the cold condition. At the time of starting up the engine it is determined whether or not the temperature of the engine is less than a certain value. If so, the heater is provided with electrical power to the maximum practicable amount, for a certain time interval after the engine is started up. Thereby, during engine heating up operation, the temperature of the sensor element is brought up to its minimum proper operating temperature as quickly as practicable, and accordingly it is ensured that engine performance and the quality of exhaust gas emissions at the time of such engine warming up operation are good. A system is also described for implementing this method.

In an internal combustion engine wherein feedback control of the air-fuel ratio is carried out in accordance with the concentration of a specific composition in the exhaust gas, so that the air-fuel ratio is close to an aimed air-fuel ratio, the atmospheric pressure is detected, and the aimed air-fuel ratio is varied in accordance with the detected atmospheric pressure.

Method and apparatus for controlling air-fuel ration in internal

The oxygen sensor has a solid electrolytic element made of an oxygen ion-conducting metal oxide. This element is formed in a cup shape, closed at one end and opened at its other end. The outer peripheral surface of the element is exposed to exhaust gas, and the inner peripheral surface of the element is exposed to the atmosphere. A first electrode is fixed to the outer peripheral surface of the element, and a second electrode is fixed to the inner peripheral surface of the element. An electrically insulating layer is formed on the outer peripheral surface of the element except where the first electrode is disposed. A metal lead of thin film, connected to the first electrode, is formed on the insulating layer. Further, a retaining lead connected to the first electrode is formed on the metal lead. This retaining lead is formed by densely sintering a conductive material and a binding material.

Oxygen sensor

An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating the sensor element. A method is disclosed for controlling the power supplied to said heater by restricting it to be less than a predetermined value. This restriction may be done by controlling the value of a relatively steady current flowing through said heater, or alternatively may be done by supplying an intermittent voltage to said heater and by controlling the duty factor of said intermittent voltage. The power supplied to said heater may be determined by detecting the current flowing through said heater, or may be determined by detecting the voltage across said heater and the current flowing through said heater. Thereby, during engine heating up operation, the temperature of the heater element is raised as quickly as practicable, without any risk of over quick heating of the heater occurring, which might lead to damage thereto. Accordingly it is ensured that engine performance and the quality of exhaust gas emissions at the time of such engine warming up operation are good. A system is also described for implementing this method.

Electric current supply to an actuator is ON-OFF controlled in such a manner that fuel supply quantity is made to be zero on condition that an engine rotation speed reaches a rotation speed less than a predetermined one in a low rotation region and a starter switch is turned OFF, whereby overrun of an engine and reckless run of a vehicle are prevented when a rotation sensor is in an abnormal condition.

Method of controlling diesel engine

An oxygen sensor according to the present invention comprises a tumbler-shaped solid electrolytic element formed of an oxygen-ion-conductive metal oxide. A first electrode and a lead electrically connected thereto are formed on the outer peripheral surface of the element which is exposed to exhaust gas. A second electrode is fixed to the inner peripheral surface of the element which is exposed to the atmosphere. The element is held by a ring-shaped metallic holder. The holder and the first electrode are electrically insulated from each other. A conductive metallic pipe member is disposed between the element and the holder. One end of the pipe member is electrically connected to the lead by means of a conductive metal ring. A partition wall extends integrally from one end of the pipe member, defining between its inner surface and the other peripheral surface of the element a space for housing the conductive metal ring between the pipe member and the lead. A seal member is interposed between the outer peripheral surfaces of the pipe member and the partition wall and the inner peripheral surface of the holder. The seal member is formed by compacting a powdered electrial insulating material.

An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating the sensor element. A method is disclosed for controlling the air/fuel ratio of the air-fuel mixture supplied to the engine, by, when the voltage of the power supply to the heater has dropped below a first predetermined value and thereafter has remained below a second predetermined value higher than the first predetermined value for longer than a predetermined time period, controlling the air/fuel ratio according to engine operational parameters by an open loop form of control with no account being taken of the output signal of the oxygen sensor, and otherwise controlling the air/fuel ratio according to these engine operational parameters by a closed loop form of control taking into account the output signal of the oxygen sensor so as to obtain an optimum air/fuel ratio for the engine by a feedback control process. Accordingly it is ensured that the air/fuel ratio of the engine is kept appropriate, even if the voltage of the battery drops so low that it can no longer properly power the oxygen sensor heater, which causes the output signal of the oxygen sensor to be no longer reliable for indicating the amount of oxygen in the exhaust gases of the engine. A system is also described for implementing this method.

Growing community of inventors

Aichi, Japan

Takao Akatsuka