| Patent application number | Description | Published |
|---|
| 20080196489 | DIAGNOSTIC METHOD AND CONTROL APPARATUS FOR GAS SENSOR - A gas sensor diagnostic method (or apparatus) is arranged to periodically obtain sensor output values of a gas sensor such as an oxygen sensor for an internal combustion engine, and to determine local extreme values from the sensor output values obtained during a period of interruption of fuel supply to the engine. Moreover, the local extreme values are compared with a first predetermined threshold level. When the number of the local extreme values reaches a predetermined first number, a diagnosis is performed to determine whether the gas sensor is in an improper condition or not, in accordance with results of the comparison of the local extreme values with the first threshold level. | 08-21-2008 |
| 20080196490 | DIAGNOSTIC METHOD AND APPARATUS FOR GAS SENSOR - A gas sensor diagnostic method includes the steps of counting the reversal number of times that a target air-fuel ratio for an air-fuel mixture to be supplied to an internal combustion engine reverses from a rich side to a lean side or from the lean side to the rich side through a specific air-fuel ratio defined as a boundary of the rich and lean sides; obtaining a detection signal of a gas sensor at constant time intervals during a diagnosis period between a timing when the count for the reversal number is started and a timing when the reversal number reaches a predetermined number; calculating a moderated signal by applying a moderation calculation using a predetermined moderation coefficient to the obtained detection signal; calculating a deviation between the obtained detection signal and the calculated moderated signal; and determining whether the gas sensor is in an abnormal state or not on the basis of the deviation. | 08-21-2008 |
| 20080196702 | DIAGNOSTIC METHOD AND CONTROL APPARATUS FOR GAS SENSOR - A gas sensor diagnostic method includes: a fuel supply detecting step of detecting an interruption of a fuel supply to the internal combustion engine, and a restart of the fuel supply after the interruption of the fuel supply; a response time period accumulating step of determining a response time period by accumulating a first time period that the sensor output value reaches from a first threshold value to a second threshold value after the detection of the interruption of the fuel supply, and a second time period that the sensor output value reaches from a third threshold value to a fourth threshold value after the detection of the restart of the fuel supply after the interruption of the fuel supply; and an abnormal state diagnosing section of determining an abnormal state of the gas sensor when the response time period is greater than a predetermined time period. | 08-21-2008 |
| 20090084172 | Diagnostic method and apparatus for gas sensor - A gas sensor diagnostic method includes the steps of counting the reversal number of times that a target air-fuel ratio for an air-fuel mixture to be supplied to an internal combustion engine reverses from a rich side to a lean side or from the lean side to the rich side through a specific air-fuel ratio defined as a boundary of the rich and lean sides; obtaining a detection signal of gas sensor at constant time intervals during a diagnosis period between a timing when the count for the reversal number is started and a timing when the reversal number reaches a predetermined number; calculating a first moderated signal by applying a first moderation calculation to the detection signal, and a second moderated signal by applying a second moderation calculation to the detection signal; calculating a deviation between the first and second moderated signals; and determining whether the gas sensor is in the abnormal state on the basis of the deviation obtained during the diagnosis period. | 04-02-2009 |
| 20110132775 | SENSOR CONTROL DEVICE AND SENSOR CONTROL METHOD - [Objective] An object is to provide a sensor control apparatus and a sensor-control-apparatus control method which can reduce variation in startup time among a plurality of times of execution of detection processing, in consideration of variation in output characteristic among a plurality of gas sensors. | 06-09-2011 |
| 20110147211 | SENSOR CONTROL APPARATUS - A sensor control apparatus includes: a gas sensor including an oxygen concentration detection cell having a first solid electrolyte body, a reference electrode and a detection electrode, and a heater; an electric current supply unit that supplies electric current to the oxygen concentration detecting cell; an activation determination unit; and a heater control unit that controls electric current supply to the heater by setting a first target temperature equal to or higher than an activation determination temperature as a target temperature when the activation determination unit determines that the temperature of the gas sensor is equal to or higher than the activation determination temperature, the sensor control apparatus further includes: an automatic stop detection unit and a first temperature switching unit that controls electric current supplied to the heater such that the target temperature of the heater is switched to a second target temperature being different from a temperature at which blackening is generated in the first solid electrolyte body when an automatic stop detection unit detects the automatic stop of the engine. | 06-23-2011 |
| 20110166816 | SENSOR CONTROL APPARATUS - An oxygen sensor control apparatus ( | 07-07-2011 |
| 20110214988 | GAS SENSOR ELEMENT, GAS SENSOR AND CONTROL SYSTEM OF GAS SENSOR - In order to compensate for variation in output of sensor elements | 09-08-2011 |
