Sensor control apparatus, sensor control system, and sensor control method

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.

Description

technical field [0001] The present invention relates to a sensor control device, a sensor control system, and a sensor control method for calculating a concentration-corresponding value representing the concentration of a specific gas contained in a gas to be detected. Background technique [0002] Conventionally, a gas sensor that detects the concentration of a specific gas contained in a gas to be detected, such as exhaust gas, has been used. For example, a NOx sensor that detects nitrogen oxide (hereinafter referred to as "NOx") as a specific gas has a detection element having an oxygen concentration detection unit in which a porous electrode is formed on an oxygen ion conductive solid electrolyte layer and a first oxygen pump unit and a second oxygen pump unit. The first oxygen pump unit sucks or sucks oxygen from the first measurement chamber into which the gas to be detected is introduced. In addition, the second oxygen pump unit sucks oxygen from the second measurem...

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Problems solved by technology

[0011] However, in the initial stage when the drive control is started and oxygen is sucked back, even if the time-varying trend shows a substantially constant trend as described above, due to individual differences (inter-individual variation) of the detection elements, there are variations A situation where there is a deviation in the period indicated by the trend over time

In the past, the detection of NOx concentration was not carried out at the initial stage of drive control, but the detection of NOx concentration was started after a predetermined time elapsed after the output of the detection element became stable. Temporal bias of the time-varying trend in suckback

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