Abstract: A NOx sensor control device is connected to a NOx sensor mounted in an internal combustion engine. The NOx sensor has a detection cell configured to detect a NOx concentration and having a solid electrolyte body and a pair of electrodes provided on a surface of the solid electrolyte body and a heater heating the detection cell. The NOx sensor control device has a heater control unit. The heater control unit is configured to, at a time when an operation of the internal combustion engine stops, perform a recovery control of the NOx sensor which is an electric current control of the heater for removing SOx adsorbed to the NOx sensor.

Abstract: A NOx sensor control device is connected to a NOx sensor mounted in an internal combustion engine. The NOx sensor has a detection cell configured to detect a NOx concentration and having a solid electrolyte body and a pair of electrodes provided on a surface of the solid electrolyte body and a heater heating the detection cell. The NOx sensor control device has a heater control unit. The heater control unit is configured to, at a time when an operation of the internal combustion engine stops, perform a recovery control of the NOx sensor which is an electric current control of the heater for removing SOx adsorbed to the NOx sensor.

Abstract: An NOx detection apparatus computes a first NOx concentration NOxpo on the basis of a second pumping current Ip2, and sets correction coefficients a, b (concentration variation correction information) on the basis of the first NOx concentration NOxpo. Therefore, the NOx detection apparatus can set the correction coefficients a, b in accordance with the concentration of NOx actually contained in a to-be-measured gas. Since the NOx detection apparatus uses Equation 3, determined by the correction coefficients a, b, for correction of the first NOx concentration NOxpo, the NOx detection apparatus can correct the first NOx concentration NOxpo in accordance with the state of change of the NOx concentration even when the magnitude of an output variation caused by a pressure change changes depending on the NOx concentration.

Abstract: An NOx detection apparatus does not always perform correction processing, but it determines whether to perform the correction processing on the basis of the result of a determination of whether a first Nox concentration is higher than a predetermined specific concentration. The first NOx concentration NOxpo calculated from a second pumping current Ip2 which changes with the actual NOx concentration. Therefore, the NOx detection apparatus can determine whether to correct the first NOx concentration NOxpo in accordance with the actual NOx concentration. Accordingly, the NOx detection apparatus can suppress a decrease in gas detection accuracy even in the case where the gas detection value based on the sensor output involves an error in a specific concentration range (concentration range of 90 ppm or higher).

Abstract: A sensor control apparatus is disclosed, including a preliminary control for supplying a constant current to a second oxygen pump cell of a gas sensor for a constant period of time so as to control to a constant level the amount of oxygen pumped out from a second measurement chamber (S40 to S50). At the beginning of drive control (S55 to S80), oxygen is pumped back into the second measurement chamber. During the pumping back operation, an NOX concentration correspondence value has a large time course change and is not stable. The NOX concentration correspondence value is corrected using correction data common among gas sensors, wherein the timing for applying the correction data is adjusted by making use of an application time determined in accordance with individual differences of each gas sensor.

Abstract: In a sensor control device, it is determined whether a gas sensor is activated. A concentration control is performed at an elapse timing which elapses by a first constant time from an activation timing at which the gas sensor is determined to be activated. A preliminary control is performed in at least a partial period between the elapse timing and a start timing at which a drive control is started.

Abstract: [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. [Means for Solution] In a sensor control apparatus, before drive control (S55 to S80) is started, preliminary control is executed so as to supply a constant current to a second oxygen pump cell over a constant time, to thereby control to a constant level the amount of oxygen pumped from a second measurement chamber to the outside of the second measurement chamber (S40 to 50). The preliminary control is executed under control conditions of the sensor control apparatus which are determined for each gas sensor and are associated with the amount of oxygen pumped from the second measurement chamber to the outside thereof.

Abstract: An NOx detection apparatus computes a first NOx concentration NOxpo on the basis of a second pumping current Ip2, and sets correction coefficients a, b (concentration variation correction information) on the basis of the first NOx concentration NOxpo. Therefore, the NOx detection apparatus can set the correction coefficients a, b in accordance with the concentration of NOx actually contained in a to-be-measured gas. Since the NOx detection apparatus uses Equation 3, determined by the correction coefficients a, b, for correction of the first NOx concentration NOxpo, the NOx detection apparatus can correct the first NOx concentration NOxpo in accordance with the state of change of the NOx concentration even when the magnitude of an output variation caused by a pressure change changes depending on the NOx concentration.

Abstract: An NOx detection apparatus does not always perform correction processing, but it determines whether to perform the correction processing on the basis of the result of a determination of whether a first Nox concentration is higher than a predetermined specific concentration. The first NOx concentration NOxpo calculated from a second pumping current Ip2 which changes with the actual NOx concentration. Therefore, the NOx detection apparatus can determine whether to correct the first NOx concentration NOxpo in accordance with the actual NOx concentration. Accordingly, the NOx detection apparatus can suppress a decrease in gas detection accuracy even in the case where the gas detection value based on the sensor output involves an error in a specific concentration range (concentration range of 90 ppm or higher).

Abstract: In a sensor control device, it is determined whether a gas sensor is activated. A concentration control is performed at an elapse timing which elapses by a first constant time from an activation timing at which the gas sensor is determined to be activated. A preliminary control is performed in at least a partial period between the elapse timing and a start timing at which a drive control is started.

Abstract: There is provided a control apparatus for a gas sensor, which has a sensor element equipped with first and second oxygen pumping cells. The sensor control apparatus is configured to drive the first oxygen pumping cell to adjust the oxygen concentration of gas under measurement, drive the second oxygen pumping cell to produce a flow of electric current according to the amount of oxygen pumped out of the oxygen concentration adjusted gas by the second oxygen pumping cell, perform specific drive control to control the amount of oxygen pumped by the second oxygen pumping cell to a predetermined level after startup of the sensor element and before the application of the drive voltage between the electrodes of the second oxygen pumping cell.

Abstract: A sensor control apparatus is disclosed, including a preliminary control for supplying a constant current to a second oxygen pump cell of a gas sensor for a constant period of time so as to control to a constant level the amount of oxygen pumped out from a second measurement chamber (S40 to S50). At the beginning of drive control (S55 to S80), oxygen is pumped back into the second measurement chamber. During the pumping back operation, an NOX concentration correspondence value has a large time course change and is not stable. The NOX concentration correspondence value is corrected using correction data common among gas sensors, wherein the timing for applying the correction data is adjusted by making use of an application time determined in accordance with individual differences of each gas sensor.

Abstract: [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. [Means for Solution] In a sensor control apparatus, before drive control (S55 to S80) is started, preliminary control is executed so as to supply a constant current to a second oxygen pump cell over a constant time, to thereby control to a constant level the amount of oxygen pumped from a second measurement chamber to the outside of the second measurement chamber (S40 to 50). The preliminary control is executed under control conditions of the sensor control apparatus which are determined for each gas sensor and are associated with the amount of oxygen pumped from the second measurement chamber to the outside thereof.

Abstract: There is provided a control apparatus for a gas sensor, which has a sensor element equipped with first and second oxygen pumping cells. The sensor control apparatus is configured to drive the first oxygen pumping cell to adjust the oxygen concentration of gas under measurement, drive the second oxygen pumping cell to produce a flow of electric current according to the amount of oxygen pumped out of the oxygen concentration adjusted gas by the second oxygen pumping cell, perform specific drive control to control the amount of oxygen pumped by the second oxygen pumping cell to a predetermined level after startup of the sensor element and before the application of the drive voltage between the electrodes of the second oxygen pumping cell.