JP2017219381A5 - - Google Patents

Claims (5)

A first electrode having a solid electrolyte layer (31) and at least a pair of electrodes (35, 36) sandwiching the solid electrolyte layer (31), to which a gas to be detected, which is exhaust gas or a mixed gas containing exhaust gas, is guided to one of the pair of electrodes. (35) comprising a sensor element (30) having a second electrode (36) provided in a reference gas chamber (38) for introducing a reference gas as the other, and applying a voltage in a limit current region, Applied to a gas sensor (20) that outputs a limiting current according to the concentration of a specific gas of
In a predetermined operation state in which fuel is burned in the internal combustion engine (10), a first current that is output when a voltage is applied in the limit current region, and a water decomposition region that is higher in voltage than the limit current region. An acquisition unit for acquiring a second current output when a voltage is applied;
A humidity estimation unit that estimates the humidity of the gas to be detected based on the difference between the first current and the second current;
A correction unit that corrects the concentration detection value of the specific gas based on the humidity of the detected gas estimated by the humidity estimation unit;
Equipped with a,
The acquisition unit acquires the first current and the second current, respectively, under a plurality of different predetermined operating states,
The humidity estimation unit is configured to determine a humidity of the gas to be detected based on a difference between the first current and the second current under each predetermined operating state and a difference in the amount of combustion moisture in each predetermined operating state. you estimate the gas sensor control unit (50).   The gas sensor control device according to claim 1, wherein the acquisition unit acquires the first current and the second current under the predetermined operation state in which a fuel injection amount in the internal combustion engine is a predetermined amount.   The gas sensor control device according to claim 1, wherein the acquisition unit sets the idle operation state to the predetermined operation state, and acquires the first current and the second current under the idle operation state. An information acquisition unit that acquires individual difference information indicating the output characteristics of the gas sensor,
The gas sensor control device according to any one of claims 1 to 3 , wherein the humidity estimation unit estimates the humidity of the detected gas based on the individual difference information. The gas sensor according to any one of claims 1 to 4 , wherein the acquisition unit acquires the first current and the second current even in a state where the detected gas is in the atmosphere in addition to the predetermined operation state. Control device.