JP5053966B2 - Sensor control device - Google Patents

Description

  The present invention relates to a sensor control device that controls a gas sensor that outputs a concentration signal corresponding to the concentration of a specific gas component in a detection target gas.

  There is known a sensor control device that controls a gas sensor that outputs a concentration signal corresponding to a specific gas component concentration in a detection target gas (for example, a NOx concentration in exhaust gas discharged from a vehicle). In this sensor control device, generally, a gas sensor is detachably connected, and in order to acquire the above concentration signal from the gas sensor, for example, energization to the gas sensor and voltage applied to a heater for heating the gas sensor are controlled. .

  By the way, a characteristic representing the relationship between the concentration signal and the specific gas component concentration (hereinafter referred to as a specific gas concentration characteristic) is slightly different for each gas sensor. That is, even if the gas sensor has the same model number, the concentration signal with respect to the actual specific gas component concentration varies slightly due to manufacturing variations. For this reason, if the specific gas component concentration is calculated based on the same specific gas concentration characteristic for a large number of gas sensors, there is a possibility that sufficiently high accuracy cannot be obtained.

Therefore, a storage medium provided on the gas sensor side is known to be configured to individually store information indicating the specific gas concentration characteristic for each gas sensor (hereinafter referred to as sensor characteristic information) (for example, (See Patent Document 1). As a result, the sensor control apparatus acquires sensor characteristic information from the storage medium of the gas sensor connected to the sensor control apparatus, and uses the sensor characteristic information set for each gas sensor to determine the concentration of the specific gas component from the concentration signal. It can be calculated with high accuracy.
Japanese Patent Laid-Open No. 11-72478

  However, in the technique described in Patent Document 1, for example, the storage medium on the gas sensor side is caused by the disconnection of the connection line between the storage medium on the gas sensor side and the sensor control device or the life of the storage medium provided on the gas sensor side. If the sensor characteristic information cannot be obtained from the sensor control device, the sensor control device cannot calculate the concentration of the specific gas component using the sensor characteristic information. For this reason, there is a problem that the concentration of the specific gas component cannot be accurately calculated.

  The present invention has been made in view of these problems, and a sensor control device capable of accurately calculating the concentration of a specific gas component even when sensor characteristic information cannot be obtained from a storage medium provided on the gas sensor side. The purpose is to provide.

  In order to achieve the above object, the invention according to claim 1 is provided with a non-volatile or volatile first storage medium to which electric power is constantly supplied and outputs a concentration signal corresponding to the concentration of the specific gas component. A sensor control device for detachably mounting a gas sensor and controlling the gas sensor, wherein the first storage medium has a concentration calculation setting value set for each gas sensor in order to calculate the concentration of the specific gas component from the concentration signal. A first concentration calculation setting value for the gas sensor is stored in advance, and a non-volatile or volatile second storage medium to which power is always supplied, and a first concentration calculation setting from the first storage medium. A first information acquisition unit for acquiring a value; an information storage unit for storing the first concentration calculation setting value acquired by the first information acquisition unit in the second storage medium as a second concentration calculation setting value; The first acquisition for determining whether the acquisition of the first concentration calculation setting value by the concentration calculation means for calculating the concentration of the specific gas component from the concentration signal and the first information acquisition means has been successful using the set value for operation. And determining the first concentration calculated by the first information acquiring unit when the first acquiring determining unit determines that the first concentration calculating setting value has been successfully acquired. When the first acquisition determining unit determines that the first concentration calculation setting value has not been successfully acquired using the setting value for concentration calculation as the setting value for concentration calculation, the second storage medium already stored in the second storage medium is used. The sensor control device is characterized in that the concentration of the specific gas component is calculated from the concentration signal using the two concentration calculation setting values as the concentration calculation setting values.

  In the sensor control apparatus configured as described above, the concentration calculation means calculates the concentration of the specific gas component from the concentration signal using the concentration calculation setting value. The first information acquisition unit acquires the first density calculation setting value from the first storage medium, and the information storage unit uses the first density calculation setting value acquired by the first information acquisition unit as the second density. Stored as a setting value for calculation in the second storage medium. Further, the first acquisition determination means determines whether or not acquisition of the first concentration calculation setting value by the first information acquisition means has succeeded.

  When the first acquisition determining unit determines that the acquisition of the first concentration calculation setting value is successful, the concentration calculating unit uses the first concentration calculating setting value acquired by the first information acquiring unit as the concentration. When the first acquisition determining means determines that the acquisition of the first concentration calculation setting value was not successful, the second concentration calculation setting already stored in the second storage medium is used as the calculation setting value. The concentration of the specific gas component is calculated from the concentration signal using the value as the concentration calculation setting value.

  Therefore, according to the sensor control device of the first aspect, if the gas sensor is mounted and the first concentration calculation setting value acquired by the first information acquisition unit is once stored in the second storage medium, then, Even when the first information acquisition unit cannot acquire the first concentration calculation setting value, the concentration of the specific gas component is determined from the concentration signal using the second concentration calculation setting value stored in the second storage medium. Can be calculated. For this reason, during the use of the gas sensor and the sensor control device after the gas sensor is mounted, for example, a communication error due to external noise or a connection line between the storage medium on the gas sensor side and the sensor control device. Even if it becomes impossible to obtain the first concentration calculation setting value from the first storage medium due to disconnection or the life of the first storage medium provided on the gas sensor side, the concentration of the specific gas component is accurately calculated. There is an effect that can be done.

  In the sensor control device according to claim 1, as set in claim 2, a preset standard concentration calculation setting value that is not set for each gas sensor is stored as the concentration calculation setting value. Nonvolatile or volatile third storage medium to which power is always supplied, second information acquisition means for acquiring a second concentration calculation setting value from the second storage medium, and second concentration calculation by the second information acquisition means Second acquisition determination means for determining whether or not acquisition of the set value for use has succeeded, and the concentration calculation means is determined by the first acquisition determination means that acquisition of the first concentration calculation set value has not been successful. In this case, when the second acquisition determining unit determines that acquisition of the second concentration calculation setting value is successful, the second concentration calculation setting value acquired by the second information acquisition unit is used for concentration calculation. Used as set value When the second acquisition determining unit determines that acquisition of the second concentration calculation setting value has not been successful, the standard concentration calculation setting value stored in the third storage medium is used as the concentration calculation setting value. Thus, the concentration of the specific gas component may be calculated from the concentration signal.

  In the sensor control device configured as described above, the second information acquisition unit acquires the second concentration calculation setting value from the second storage medium, and then the second acquisition determination unit performs the second acquisition of the second information acquisition unit. It is determined whether or not acquisition of the two density calculation setting values has succeeded. When the first acquisition determining unit determines that the acquisition of the first concentration calculation setting value is not successful, the concentration calculation unit further determines that the acquisition of the second concentration calculation setting value is successful. When judged by the judging means, the second density calculation setting value acquired by the second information acquisition means is used as the density calculation setting value, and the second acquisition indicates that the acquisition of the second density calculation setting value was not successful. If it is determined by the determination means, the concentration of the specific gas component is calculated from the concentration signal using the standard concentration calculation setting value stored in the third storage medium as the concentration calculation setting value.

  According to the sensor control device configured as described above, the concentration of the specific gas component can be calculated from the concentration signal using the concentration calculation setting value stored in the third storage medium. Even if the second concentration calculation setting value stored in the table disappears for some reason, the deterioration of the concentration calculation accuracy can be suppressed.

  By the way, in the sensor control apparatus according to the first aspect, when a gas sensor attached to the sensor control apparatus fails, it is necessary to replace it with a normal gas sensor. And after mounting a normal gas sensor, a 1st information acquisition means acquires the setting value for 1st density | concentration calculation from the 1st storage medium of this gas sensor. At this time, if acquisition of the first density calculation setting value by the first information acquisition unit is not successful, the second density calculation setting value stored in the second storage medium is used as the density calculation setting value. Used as

  However, the second concentration calculation setting value stored in the second storage medium is not the concentration calculation setting value set for the newly installed normal gas sensor, but the concentration set for the failed gas sensor. This is a setting value for calculation. For this reason, the concentration calculation means calculates the concentration of the specific gas component from the concentration signal output from the newly installed normal gas sensor using the concentration calculation setting value set for the failed gas sensor.

  Therefore, in the sensor control device according to the first aspect, the preset standard concentration calculation setting value that is not set for each gas sensor is stored as the concentration calculation setting value as described in the third aspect. Whether or not a preset third sensor replacement condition indicating that it is necessary to replace the non-volatile or volatile third storage medium to which power is always supplied and the gas sensor connected to the sensor control device is satisfied The concentration calculation means further determines that the sensor replacement condition is satisfied when the first acquisition determination means determines that the acquisition of the first concentration calculation setting value has not succeeded. If it is determined that the replacement condition is not established, the second concentration calculation setting value stored in the second storage medium is used as the concentration calculation setting value, and the sensor replacement condition is determined. Is determined by the replacement condition satisfaction determination means, the concentration value of the specific gas component is calculated from the concentration signal using the standard concentration calculation setting value stored in the third storage medium as the concentration calculation setting value. It is good to do. Examples of the sensor replacement condition include “detection of a gas sensor failure”, “use of a predetermined period of use of the gas sensor”, and the like.

  According to the sensor control device configured as described above, when the acquisition of the first first concentration calculation setting value after the gas sensor replacement is not successful, the standard concentration stored in the third storage medium is stored. The density is calculated using the calculation setting value as the density calculation setting value. Here, the standard concentration calculation set value is a preset value that is not set for each gas sensor. That is, the standard concentration calculation setting value is compared with the case where each gas sensor uses the standard concentration calculation setting value to calculate the concentration of the specific gas component, compared to the case where the concentration calculation setting value set for each gas sensor is used. It is set to a standard (average) value so that a large difference does not occur.

  Therefore, compared with the case where the concentration of the specific gas component is calculated from the concentration signal of the newly installed gas sensor using the concentration calculation setting value set for the gas sensor that was installed before replacement. Thus, the possibility that the difference between the actual concentration of the specific gas component and the calculated concentration of the specific gas component becomes large can be reduced.

  In the sensor control device according to claim 1, as set forth in claim 4, a preset standard concentration calculation setting value that is not set for each gas sensor is stored as the concentration calculation setting value. A non-volatile or volatile third storage medium to which electric power is always supplied, and a sensor replacement determination unit that determines whether or not a gas sensor connected to the sensor control device has been replaced. When it is determined by the first acquisition determining means that acquisition of the set value for one concentration calculation has not been successful, if the sensor replacement determining means determines that the gas sensor has not been replaced, it is stored in the second storage medium. When the sensor replacement determination means determines that the gas sensor has been replaced using the second concentration calculation setting value as the concentration calculation setting value, the third storage medium The standard concentration calculating setting values stored with the concentration calculation for setting values, may be to calculate the concentration of a specific gas component from the concentration signal.

  According to the sensor control device configured as described above, when the acquisition of the first first concentration calculation setting value after the gas sensor replacement is not successful, the standard concentration stored in the third storage medium is stored. The density is calculated using the calculation setting value as the density calculation setting value.

  Therefore, compared with the case where the concentration of the specific gas component is calculated from the concentration signal of the newly installed gas sensor using the concentration calculation setting value set for the gas sensor that was installed before replacement. Thus, the possibility that the difference between the actual concentration of the specific gas component and the calculated concentration of the specific gas component becomes large can be reduced.

  Note that the above-mentioned “standard concentration calculation setting value that is not set for each gas sensor as the concentration calculation setting value” indicates that the usable range of this standard concentration calculation setting value is the model number of the gas sensor. It may be set so that it can be applied only to the same one, or it may be set so that it can be applied to at least one that has the same model number of the gas sensor. You may set so that what differs may be applied.

  Moreover, in the sensor control apparatus according to any one of claims 1 to 4, as described in claim 5, the gas sensor is a first in which at least a part of the periphery is formed of one or more solid electrolyte bodies. A first oxygen pumping cell provided in the first measurement chamber has a measurement chamber and a second measurement chamber, and the oxygen concentration of the gas to be measured flowing from the first measurement chamber to the second measurement chamber is constant. Used to pump or pump oxygen, dissociate oxide in the second measurement chamber to generate oxygen, and pump this oxygen from the second measurement chamber using the second oxygen pumping cell in the second measurement chamber Thus, the concentration of the specific gas component may be detected. By mounting the gas sensor having such a configuration on the sensor control device of the present invention, the concentration of the specific gas component can be accurately calculated.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram showing a schematic configuration of a gas detection device 1 including a gas sensor control device 2 to which the present invention is applied. FIG. 2 is a front view of a male connector 51 showing the arrangement of a semiconductor recording medium 6. FIG. FIG. 4 is a front view of the female connector 51 showing the arrangement of the recording medium 6, and FIG.

  As shown in FIG. 1, the gas detection device 1 includes a gas sensor control device 2 and a NOx gas sensor 3, and a specific gas in the exhaust gas of an internal combustion engine such as an automobile or various combustion equipment such as a boiler (this embodiment) In the form, it is used for the purpose of detecting the concentration of NOx).

  A connection cable 4 having a connector 41 at the tip is connected to the gas sensor control device 2, and a connection cable 5 having a connector 51 at the tip is connected to the NOx gas sensor 3. And the gas sensor control apparatus 2 and the NOx gas sensor 3 are electrically connected by the connector 41 and the connector 51 being fitted. For this reason, if the connectors 41 and 51 are removed, the NOx gas sensor 3 can be easily replaced. The NOx gas sensor 3 has a known configuration including a NOx gas sensor element 31 to be described later, a housing that houses the element 31, a connection cable 5 that is electrically connected to the element 31, and a connector 51.

  As shown in FIGS. 2 and 3, the connector 51 includes a semiconductor recording medium 6 (for example, a product name touch memory probe (DS9092) and a product name add-only memory (DS2505) manufactured by Dallas Semiconductor Corporation). Has been. The semiconductor recording medium 6 is attached as shown in FIG. 2 when the connector 51 of the NOx gas sensor 3 is male, and as shown in FIG. 3 when the connector 51 is female. In either case, the plurality of pins (not shown) provided on the connector 51 are connected to unused pins and are attached so as to be electrically connected to the gas sensor control device 2 via the connector 51. It has been. That is, the semiconductor recording medium 6 is integrated with the connector 51 of the NOx gas sensor 3.

  The semiconductor recording medium 6 has information for setting a characteristic representing a relationship between a first pump current Ip1 and an oxygen concentration, which will be described later, for the NOx gas sensor 3 in which the semiconductor recording medium 6 is integrated (that is, (O2 gain and O2 offset) and information for setting a characteristic representing a relationship between a second pump current Ip2 and a NOx concentration described later (that is, NOx gain and NOx offset) are stored. Hereinafter, the O2 gain and O2 offset and the NOx gain and NOx offset are collectively referred to as sensor characteristic information. The sensor characteristic information is information obtained by individually inspecting the sensor characteristic information with a predetermined inspection device for each NOx gas sensor element 31 obtained in the manufacturing process of the NOx gas sensor 3. Is stored in the semiconductor recording medium 6 incorporated in the NOx gas sensor 3 including the NOx gas sensor element 31 provided for the above.

  As shown in FIG. 4, the gas sensor control device 2 includes a microcomputer including a central processing unit (CPU) 191, a RAM 192, a ROM 193, an EEPROM 194, a signal input / output unit 195, etc. as a main part, and a NOx gas sensor. It is configured to include a known energization circuit (not shown) disclosed in Japanese Patent Application Laid-Open No. 11-72478 for energizing the element 31. Of these, the ROM 193 does not set each NOx gas sensor individually, but stores sensor characteristic information of standard values set in advance as default values. The signal input / output unit 195 includes a semiconductor recording medium 6, a first pump first electrode 135, a first pump second electrode 137, a detection electrode 155, a reference electrode 157, and a second pump first, which will be described later. The electrode 145, the second pump second electrode 147, and the heater 175 are connected via an energization circuit (not shown).

  The gas sensor control device 2 executes a process for driving and controlling the NOx gas sensor element 31, a sensor characteristic information acquisition process for acquiring sensor characteristic information, a gas concentration calculation process for calculating the NOx concentration in the exhaust gas, and the like.

  Next, the NOx gas sensor element 31 will be described. In FIG. 4, the NOx gas sensor element 31 is shown as a cross-sectional view showing the internal structure. In the following description, the left side of the NOx gas sensor element 31 shown in FIG. 4 will be described as the front end side, and the right side will be described as the rear end side. FIG. 4 shows the internal configuration of the front end portion of the NOx gas sensor element 31, and the rear end portion is not shown.

  The NOx gas sensor element 31 has a structure in which a first pump cell 111, an oxygen partial pressure detection cell 112, and a second pump cell 113 are stacked via insulating layers 114 and 115 mainly composed of alumina. Further, in the NOx gas sensor element 31, a heater unit 180 is stacked on the second pump cell 113 side.

  The first pump cell 111 includes a first solid electrolyte layer 131 made of zirconia having oxygen ion conductivity, a first pump first electrode 135 and a first pump disposed so as to sandwich the first solid electrolyte layer 131. And a first porous electrode 121 made of the second electrode 137 for use. The first pump first electrode 135 and the first pump second electrode 137 are made of platinum, platinum alloy, cermet containing platinum and ceramics (for example, a solid electrolyte body), and the like. The protective layer 122 made of a porous body is formed.

  The oxygen partial pressure detection cell 112 includes a detection solid electrolyte layer 151 made of zirconia having oxygen ion conductivity, and a detection electrode 155 and a reference electrode 157 arranged so as to sandwich the detection solid electrolyte layer 151. And a porous electrode 123 for use. The detection electrode 155 and the reference electrode 157 are made of platinum, a platinum alloy, cermet containing platinum and ceramics (for example, a solid electrolyte body), or the like.

  The second pump cell 113 includes a second solid electrolyte layer 141 made of zirconia having oxygen ion conductivity, and a first second pump pump disposed on the surface of the second solid electrolyte layer 141 facing the insulating layer 115. An electrode 145 and a second porous electrode 125 including a second pump second electrode 147 are formed. The first electrode 145 for the second pump and the second electrode 147 for the second pump are formed of platinum, a platinum alloy, cermet containing platinum and ceramics (for example, a solid electrolyte body), or the like.

  A first measurement chamber 159 into which a measurement target gas is introduced is formed inside the NOx gas sensor element 31. Exhaust gas, which is a measurement target gas, is introduced into the first measurement chamber 159 from the outside through the first diffusion resistor 116 disposed between the first pump cell 111 and the oxygen partial pressure detection cell 112.

  The first diffusion resistor 116 is formed of a porous body, and is disposed in the measurement target gas introduction path 14 from the opening on the tip side of the NOx gas sensor element 31 to the first measurement chamber 159 to perform the first measurement. The introduction amount (passage amount) of the measurement target gas per unit time into the chamber 159 is limited.

  The introduction path 14 is a region on the tip side (left side in the drawing) of the first measurement chamber 159 in the space surrounded by the first pump cell 111 and the oxygen partial pressure detection cell 112. The first pump first electrode 135 of the first pump cell 111 (specifically, the first pump first electrode 135 covered with the protective layer 122) and the detection electrode 155 of the oxygen partial pressure detection cell 112 are as follows. The first measurement chamber 159 is disposed so as to face the first measurement chamber 159.

  Further, a second diffusion resistor 117 made of a porous body is provided on the rear end side (right side in the drawing) of the first measurement chamber 159, and the second pump first electrode 145 and the second diffusion resistor are provided. A second measurement chamber 161 is formed between the first measurement chamber 117 and the second measurement chamber 161. The second measurement chamber 161 is formed so as to penetrate the oxygen partial pressure detection cell 112 in the stacking direction.

  Further, in the inside of the NOx gas sensor element 31, in addition to the second measurement chamber 161, between the detection solid electrolyte layer 151 of the oxygen partial pressure detection cell 112 and the second solid electrolyte layer 141 of the second pump cell 113. A reference oxygen chamber 118 made of a porous material is formed. The second measurement chamber 161 and the reference oxygen chamber 118 are formed along the second pump cell 113 in this order from the rear end side to the front end side. Further, since a small current is supplied from the gas sensor control device 2 to the oxygen partial pressure detection cell 112, oxygen is sent from the first measurement chamber 159 to the reference oxygen chamber 118 through the solid electrolyte layer 151 for detection. The reference oxygen chamber 118 is set to a predetermined oxygen partial pressure atmosphere (oxygen partial pressure atmosphere serving as a reference for concentration detection).

The reference electrode 157 of the oxygen partial pressure detection cell 112 and the second pump second electrode 147 of the second pump cell 113 are arranged so as to face the reference oxygen chamber 118.
The heater unit 180 is configured by laminating sheet-like insulating layers 171 and 173 made of insulating ceramics such as alumina. The heater unit 180 includes a heater 175 mainly composed of Pt between the insulating layers 171 and 173.

  The NOx gas sensor element 31 configured as described above can pump (pump out) the oxygen present in the first measurement chamber 159 by the first pump cell 111, and the oxygen partial pressure detection cell 112 can The oxygen concentration difference (oxygen partial pressure difference) between the reference oxygen chamber 118 and the first measurement chamber 159 whose concentration (oxygen partial pressure) is controlled to be constant, that is, the oxygen concentration (oxygen partial pressure) inside the first measurement chamber 159 is set. It can be measured.

  The NOx gas sensor element 31 is driven by the gas sensor control device 2, and each gas (first pump cell 111, second pump cell 113, oxygen partial pressure) is driven by the gas sensor control device 2 driving the heater 175. The detection cell 112) is heated to the activation temperature.

  The gas sensor control device 2 drives and controls the heater 175 to heat the NOx gas sensor element 31 to the activation temperature (for example, 750 ° C.). In this state, the voltage Vs across the oxygen partial pressure detection cell 112 is set in advance. The first pump current Ip1 flowing through the first pump cell 111 is controlled so as to be a constant voltage (for example, 425 mV).

  The gas sensor control device 2 applies a second pump voltage Vp2 having a predetermined control voltage value V0 (for example, 450 mV) to the second pump cell 113. As a result, in the second measurement chamber 161, NOx is dissociated (reduced) by the catalytic action of the second porous electrode 125 constituting the second pump cell 113, and oxygen ions obtained by the dissociation are converted into the second pump second electrode. The second pump current Ip2 flows by moving the second solid electrolyte layer 141 between the first electrode 145 and the second pump second electrode 147. That is, the second pump cell 113 dissociates the specific gas component (NOx (nitrogen oxide)) to be detected present in the second measurement chamber 161 and pumps oxygen from the second measurement chamber 161 to the reference oxygen chamber 118. .

The oxygen ions (O ²⁻ ) dissociated at the second pump first electrode 145 in the second measurement chamber 161 move to the second pump second electrode 147 through the second solid electrolyte layer 141, In the second pump second electrode 147, the oxygen (O ₂ ) is released into the reference oxygen chamber 118.

  That is, the gas sensor control device 2 controls the oxygen concentration (oxygen partial pressure) in the first measurement chamber 159 by the pumping operation of the first pump cell 111 while being connected to the NOx gas sensor element 31 via the connector 51 and the connection cable 5. Adjusting and setting the oxygen concentration (oxygen partial pressure) in the second measurement chamber 161 to a NOx detection concentration capable of NOx detection, and performing a process of detecting the NOx concentration based on the magnitude of the second pump current Ip2. . Then, the NOx concentration information detected by the gas sensor control device 2 is sent to an external device (for example, engine ECU) not shown in FIG. 1 or FIG.

  Next, a procedure of sensor characteristic information acquisition processing executed by the gas sensor control device 2 (specifically, a microcomputer configuring the gas sensor control device 2) will be described with reference to FIG. FIG. 5 is a flowchart showing sensor characteristic information acquisition processing. This sensor characteristic information acquisition process is a process repeatedly executed while the gas sensor control device 2 is activated.

  When the sensor characteristic information acquisition process is started, the gas sensor control device 2 first reads data stored in the semiconductor recording medium 6 in S10. In S20, it is determined whether or not the data stored in the semiconductor recording medium 6 has been successfully read.

  If the reading is successful (S20: YES), it is determined in S30 whether or not the same sensor characteristic information as the sensor characteristic information included in the read data is stored in the EEPROM 194. To do. If the same sensor characteristic information is stored in the EEPROM 194 (S30: YES), the process proceeds to S50. On the other hand, if the same sensor characteristic information is not stored in the EEPROM 194 (S30: NO), the sensor characteristic information read in S10 is written in the EEPROM 194 in S40, and the process proceeds to S50. If sensor characteristic information is already stored in the EEPROM 194, the sensor characteristic information read in S10 is written (overwritten).

  In S50, the sensor characteristic information read in S10 is written in the RAM 192, and the sensor characteristic information acquisition process is temporarily terminated. If sensor characteristic information is already stored in the RAM 192, the sensor characteristic information read in S10 is written (overwritten).

  If the reading fails in S20 (S20: NO), the data stored in the EEPROM 194 is read in S60. In S70, it is determined whether or not the data stored in the EEPROM 194 has been successfully read.

  Here, when reading fails (S70: NO), it transfers to S100. On the other hand, if the reading is successful (S70: YES), it is determined in S80 whether or not sensor characteristic information is stored in the EEPROM 194. Here, when sensor characteristic information is not memorize | stored (S80: NO), it transfers to S100. On the other hand, if the sensor characteristic information is stored (S80: YES), the sensor characteristic information stored in the EEPROM 194 is written in the RAM 192 in S90, and the sensor characteristic information acquisition process is temporarily terminated. If sensor characteristic information is already stored in the RAM 192, the sensor characteristic information read in S60 is written (overwritten).

  In S100, the sensor characteristic information stored in the ROM 193 is read. In S110, the sensor characteristic information read in S100 is written in the RAM 192. If sensor characteristic information is already stored in the RAM 192, the sensor characteristic information read in S100 is written (overwritten).

  Thereafter, in S120, default notification information indicating that sensor characteristic information that is a default value is used is sent to an external device (for example, engine ECU) not shown in FIG. 4, and the sensor characteristic information acquisition process is temporarily terminated. To do. By sending out the default notification information, the external device can recognize that the accuracy of the value of the NOx concentration calculated in the gas sensor control device 2 may be deteriorated.

  Next, the procedure of the gas concentration calculation process executed by the gas sensor control device 2 will be described with reference to FIG. FIG. 6 is a flowchart showing the gas concentration calculation process. This gas concentration calculation process is a process repeatedly executed while the gas sensor control device 2 is activated.

  When the gas concentration calculation process is started, the gas sensor control device 2 uses the sensor characteristic information stored in the RAM 192 to calculate the NOx concentration from the values of the second pump current Ip2 and the first pump current Ip1 in S210. The gas concentration calculation process is once completed. Note that a method for calculating the NOx concentration based on the sensor characteristic information and the value of the second pump current Ip2 is known in Japanese Patent Application Laid-Open No. 11-72478, and a description thereof will be omitted.

  In the gas sensor control device 2 configured as described above, the NOx concentration is calculated using the sensor characteristic information (S50, S90, S110, S210). The sensor characteristic information is acquired from the semiconductor recording medium 6 (S10), and the acquired sensor characteristic information is stored in the EEPROM 194 (S40). Further, it is determined whether the sensor characteristic information has been successfully acquired from the semiconductor recording medium 6 (S20).

  If it is determined that the acquisition of the sensor characteristic information from the semiconductor recording medium 6 is successful (S20: YES), the NOx concentration is calculated using the acquired sensor characteristic information (S50, S210), and the semiconductor recording medium is obtained. 6, if it is determined that the acquisition of sensor characteristic information has not succeeded (S20: NO), the NOx concentration is calculated using the sensor characteristic information already stored in the EEPROM 194 (S60, S90, S210).

  Therefore, according to the gas sensor control device 2, once the sensor characteristic information acquired from the semiconductor recording medium 6 is stored in the EEPROM 194, even if the sensor characteristic information cannot be acquired from the semiconductor recording medium 6 thereafter, the EEPROM 194. The NOx concentration can be calculated using the sensor characteristic information stored in. For this reason, during the use of the NOx gas sensor element 3 and the gas sensor control apparatus 2 after the NOx gas sensor element 3 is mounted on the gas sensor control apparatus 2, for example, communication errors due to external noise or the semiconductor recording medium 6 Even when the sensor characteristic information cannot be obtained from the semiconductor recording medium 6 due to disconnection of the connection line with the gas sensor control device 2 or the life of the semiconductor recording medium 6 provided on the NOx gas sensor element 3 side, There is an effect that the NOx concentration can be accurately calculated.

  When it is determined that the acquisition of sensor characteristic information from the semiconductor recording medium 6 has not been successful (S20: NO), the sensor characteristic information is acquired from the EEPROM 194 (S60), and the acquisition of the sensor characteristic information has succeeded. (S70), when it is determined that the acquisition of the sensor characteristic information is successful (S70: YES), the NOx concentration is calculated using the sensor characteristic information acquired from the EEPROM 194 (S90, S210), When it is determined that the acquisition of the sensor characteristic information is not successful (S70: NO), the NOx concentration is calculated using the sensor characteristic information stored in the ROM 193 (S100, S110, S210).

  For this reason, since the NOx concentration can be calculated using the standard value sensor characteristic information stored in the ROM 193, even if the sensor characteristic information stored in the EEPROM 194 disappears for some reason. Thus, there is an effect that the deterioration of the density calculation accuracy can be suppressed to the minimum.

  In the embodiment described above, the gas sensor control device 2 is the sensor control device in the present invention, the NOx gas sensor element 31, the NOx gas sensor 3 including the connector 51 is the gas sensor in the present invention, the semiconductor recording medium 6 is the first storage medium in the present invention, The EEPROM 194 is the second storage medium in the present invention, the process in S10 is the first information acquisition means in the present invention, the process in S40 is the information storage means in the present invention, the process in S210 is the concentration calculation means in the present invention, and the process in S20 is the present process. The first acquisition determination means in the present invention, the second pump current Ip2 is the concentration signal in the present invention, the sensor characteristic information stored in the semiconductor recording medium 6 is the first concentration calculation setting value in the present invention, and the sensor characteristics stored in the EEPROM 194 The information is the second density calculation setting value in the present invention.

  The ROM 193 is the third storage medium in the present invention, the process in S60 is the second information acquisition means in the present invention, the process in S70 is the second acquisition determination means in the present invention, and the sensor characteristic information stored in the ROM 193 is the present invention. Is a set value for standard density calculation.

The first pump cell 111 is a first oxygen pumping cell in the present invention, and the second pump cell 113 is a second oxygen pumping cell in the present invention.
(Second Embodiment)
A second embodiment of the present invention will be described below with reference to the drawings. In the second embodiment, only parts different from the first embodiment will be described.

  The gas detection device 1 of the second embodiment is the same as that of the first embodiment except that the sensor characteristic information acquisition processing is changed and a backup invalidity determination processing executed by the gas sensor control device 2 is added.

  First, the procedure of the sensor characteristic information acquisition process of the second embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing sensor characteristic information acquisition processing of the second embodiment. In addition, the sensor characteristic information acquisition process of 2nd Embodiment is a process performed only once immediately after starting the gas sensor control apparatus 2. FIG.

The sensor characteristic information acquisition process of the second embodiment is the same as that of the first embodiment except that the processes of S25 and S55 are added.
That is, when it is determined in S20 that acquisition of sensor characteristic information from the semiconductor recording medium 6 has not succeeded (S20: NO), a backup information invalid flag set in a backup invalidity determination process described later is set in S25. It is determined whether it is set. If the backup information invalid flag is set (S25: YES), the process proceeds to S100. On the other hand, when the backup information invalid flag is cleared (S25: NO), the process proceeds to S60.

When the process of S50 ends, the backup information invalid flag is cleared in S55, and the sensor characteristic information acquisition process is temporarily ended.
Next, the backup invalidity determination process performed by the gas sensor control device 2 will be described with reference to FIG. FIG. 8 is a flowchart showing backup invalidity determination processing. This backup invalidity determination process is a process that is repeatedly executed while the gas sensor control device 2 is activated.

  When the backup invalidity determination process is started, the gas sensor control device 2 first determines in S310 whether or not the NOx gas sensor 3 connected to the gas sensor control device 2 has failed. The failure of the NOx gas sensor 3 includes, for example, disconnection / short circuit in the current path between the NOx gas sensor 3 and the gas sensor control device 2.

  If the NOx gas sensor 3 has failed (S310: YES), the backup information invalid flag provided in the EEPROM 194 is set in S320, and the backup invalidity determination process is temporarily terminated. On the other hand, if the NOx gas sensor 3 has not failed (S310: NO), the backup invalidity determination process is temporarily terminated.

  In the gas sensor control device 2 configured as described above, first, when the NOx gas sensor 3 fails (S310: YES), the backup information invalid flag provided in the EEPROM 194 is set (S320). Here, since the NOx gas sensor 3 has failed, it is necessary to replace it with a normal NOx gas sensor 3. For this reason, the power supply of the gas sensor control apparatus 2 is once turned off. When the replacement of the NOx gas sensor 3 is completed, the power supply of the gas sensor control device 2 is turned on. Thereby, the gas sensor control apparatus 2 starts and reads the data memorize | stored in the semiconductor recording medium 6 (S10).

If the reading is successful (S20: YES), the NOx concentration is calculated using the acquired sensor characteristic information (S50, S210).
On the other hand, if the acquisition of the sensor characteristic information from the semiconductor recording medium 6 is not successful (S20: NO), it is determined whether or not the backup information invalid flag is set (S25). Here, since the backup information invalid flag is set due to a failure before the gas sensor control device 2 is turned off (S25: YES), the NOx concentration is calculated using the sensor characteristic information stored in the ROM 193. (S100, S110, S210).

  Therefore, according to the gas sensor control device 2, when the acquisition of the first sensor characteristic information after the replacement of the NOx gas sensor 3 is not successful, the standard value of the sensor characteristic information stored in the ROM 193 is stored. Can be used to calculate the NOx concentration.

  Here, the sensor characteristic information stored in the ROM 193 is a standard value. That is, this sensor characteristic information is compared with the case where each NOx gas sensor 3 uses the sensor characteristic information set for each NOx gas sensor 3 when calculating the concentration of the specific gas component using this sensor characteristic information. It is set so that there is no big difference.

  For this reason, the actual NOx concentration and the calculated NOx concentration are compared with the case where the NOx concentration is calculated using the sensor characteristic information set for the NOx gas sensor 3 mounted before the replacement. It is possible to reduce the possibility that the difference between the two becomes large.

In the embodiment described above, the process of S310 is a replacement condition establishment determination means in the present invention, and the determination condition of S310 is a sensor replacement condition in the present invention.
(Third embodiment)
A third embodiment of the present invention will be described below with reference to the drawings. In the third embodiment, only parts different from the first embodiment will be described.

  The gas detection device 1 according to the third embodiment is the same as the first embodiment except that the sensor characteristic information acquisition process is changed, and that a backup invalidity determination process and a backup process executed by the gas sensor control device 2 are added. It is.

  First, the procedure of the sensor characteristic information acquisition process of the third embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing sensor characteristic information acquisition processing according to the third embodiment. In addition, the sensor characteristic information acquisition process of 3rd Embodiment is a process performed only once immediately after starting the gas sensor control apparatus 2. FIG.

The sensor characteristic information acquisition process of the third embodiment is the same as that of the first embodiment except that the processes of S25, S55, and S95 are added.
That is, when it is determined in S20 that acquisition of sensor characteristic information from the semiconductor recording medium 6 has not succeeded (S20: NO), a backup information invalid flag set in a backup invalidity determination process described later is set in S25. It is determined whether it is set. If the backup information invalid flag is set (S25: YES), the process proceeds to S100. On the other hand, when the backup information invalid flag is cleared (S25: NO), the process proceeds to S60.

When the process of S50 ends, the backup information invalid flag is cleared in S55, and the sensor characteristic information acquisition process is temporarily ended.
When the process of S90 is completed, the backup information use flag provided in the EEPROM 194 is set in S95, and the sensor characteristic information acquisition process is temporarily ended.

  Next, the backup invalidity determination process performed by the gas sensor control device 2 will be described with reference to FIG. FIG. 10 is a flowchart showing backup invalidity determination processing. This backup invalidity determination process is a process that is repeatedly executed while the gas sensor control device 2 is activated.

  When the backup invalidity determination process is started, first, in S410, the gas sensor control device 2 determines whether or not a sensor replacement signal indicating that the NOx gas sensor 3 connected to the gas sensor control device 2 has been replaced has been acquired. to decide. The sensor replacement signal is a signal sent from an external device (for example, engine ECU) not shown in FIG. For example, an operator who replaces the NOx gas sensor 3 performs an operation of writing information indicating that the NOx gas sensor 3 has been replaced in the information storage area of the external device after replacing the NOx gas sensor 3. Do. Thereby, it is possible to transmit a sensor replacement signal from the external device.

  If it is determined in S410 that the sensor replacement signal has been acquired (S410: YES), the backup information invalid flag provided in the EEPROM 194 is set in S420, and the backup invalidity determination process is temporarily terminated. On the other hand, if it is determined that the sensor replacement signal has not been acquired (S410: NO), the backup invalidity determination process is temporarily terminated.

  Next, the procedure of backup processing executed by the gas sensor control device 2 will be described with reference to FIG. FIG. 11 is a flowchart showing the backup process. This backup process is a process repeatedly executed while the gas sensor control device 2 is activated.

  When the backup process is started, the gas sensor control device 2 first determines in S510 whether or not the backup information invalid flag provided in the EEPROM 194 is set. If the backup information invalid flag is not set (S510: NO), the backup process is temporarily terminated.

  On the other hand, if the backup information invalid flag is set (S510: YES), it is determined in S520 whether the backup information use flag is set. Here, when the backup information use flag is not set (S520: NO), the backup process is temporarily ended.

  On the other hand, if the backup information use flag is set (S520: YES), the sensor characteristic information stored in the ROM 193 is read in S530, and the sensor characteristic information read in S530 is stored in the RAM 192 in S540. Write. If sensor characteristic information is already stored in the RAM 192, the sensor characteristic information read in S100 is written (overwritten).

  Thereafter, in S550, default notification information indicating that the sensor characteristic information which is a default value is used is sent to an external device (for example, engine ECU) not shown in FIG. 4, and the backup processing is temporarily ended.

  In the gas sensor control device 2 configured as described above, first, when the work of replacing the NOx gas sensor 3 is performed, the power of the gas sensor control device 2 is temporarily turned off before the replacement work is started. Then, when the replacement work of the NOx gas sensor 3 is completed, the power supply of the gas sensor control device 2 is turned on. Thereby, the gas sensor control apparatus 2 starts and reads the data memorize | stored in the semiconductor recording medium 6 (S10). If the reading is successful (S20: YES), the NOx concentration is calculated using the acquired sensor characteristic information (S50, S210).

  On the other hand, if the acquisition of the sensor characteristic information from the semiconductor recording medium 6 is not successful (S20: NO), it is determined whether or not the backup information invalid flag is set (S25).

  Here, since the gas sensor control device 2 has just been started, a sensor replacement signal has not been acquired from the external device (S410: NO), and the backup information invalid flag has not been set. Therefore, it is determined that the backup information invalid flag is not set (S25: NO), and the backup information use flag is set (S95).

  Thereafter, when a sensor replacement signal is acquired from the external device (S410: YES), a backup information invalid flag is set (S420). Accordingly, since the backup information invalid flag and the backup information use flag are set (S510, S520: YES), the NOx concentration is calculated using the sensor characteristic information stored in the ROM 193 (S530, S540, S210). .

  Therefore, according to the gas sensor control device 2, when the acquisition of the first sensor characteristic information after the replacement of the NOx gas sensor 3 is not successful, the standard value of the sensor characteristic information stored in the ROM 193 is stored. Can be used to calculate the NOx concentration.

  Here, the sensor characteristic information stored in the ROM 193 is a standard value. That is, this sensor characteristic information is compared with the case where each NOx gas sensor 3 uses the sensor characteristic information set for each NOx gas sensor 3 when calculating the concentration of the specific gas component using this sensor characteristic information. It is set so that there is no big difference.

  For this reason, the actual NOx concentration and the calculated NOx concentration are compared with the case where the NOx concentration is calculated using the sensor characteristic information set for the NOx gas sensor 3 mounted before the replacement. It is possible to reduce the possibility that the difference between the two becomes large.

In the embodiment described above, the process of S410 is a sensor replacement determination unit in the present invention.
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, As long as it belongs to the technical scope of this invention, a various form can be taken.

  For example, in the above-described embodiment, the semiconductor recording medium 6 using the touch memory probe is shown. However, the present invention is not limited to this. For example, a nonvolatile memory such as an EEPROM or a volatile memory to which power is constantly supplied. If it is.

  In the above embodiment, the acquired sensor characteristic information is stored in the EEPROM 194. However, the storage medium is not limited to the EEPROM, and is a non-volatile storage medium or a volatile storage to which power is always supplied. Any medium can be used.

  In the above embodiment, the sensor characteristic information having a standard value is stored in the ROM 193. However, the storage medium is not limited to the ROM, and a nonvolatile storage medium or a volatilization in which electric power is always supplied. Any storage medium can be used.

  Furthermore, in the above embodiment, when the sensor characteristic information is stored in one area in the semiconductor recording medium 6 as the first storage means, and the acquisition of the sensor characteristic information in the one area is not successful, the second storage means In this example, the sensor characteristic information stored in the EEPROM 194 is acquired, but a plurality of sensor characteristic information having the same value is stored in a plurality of areas of the semiconductor recording medium 6 as the first storage unit. The present invention can be applied. In such a form, the sensor characteristic information of a certain area of the semiconductor recording medium 6 is read, and when the sensor characteristic information cannot be read from the one area, the process of immediately reading the sensor characteristic information of the EEPROM 194 is executed. Instead, the gas sensor control device 2 is configured to execute a process for determining whether or not the sensor characteristic information can be read from another area of the semiconductor recording medium 6. If the sensor characteristic information can be acquired from any of the plurality of areas, the sensor characteristic information is written in the RAM 192. On the other hand, if the sensor characteristic information cannot be acquired from any of the plurality of areas, it is stored in the EEPROM 194. The sensor characteristic information may be read.

  In addition, the standard value sensor characteristic information stored in the ROM 193 may be a standard value for each NOx gas sensor of the same model number. A standard value may be set for each gas sensor.

  In the second embodiment, the gas sensor control device 2 determines whether or not the NOx gas sensor 3 has failed. However, devices other than the gas sensor control device 2 determine the failure of the NOx gas sensor 3, and transmit information indicating the determination result to the gas sensor control device 2, so that the gas sensor control device 2 is based on the information indicating the determination result. A failure of the NOx gas sensor 3 may be determined.

  In the third embodiment, a sensor replacement signal is transmitted from an external device to the gas sensor control device 2 so that the gas sensor control device 2 can determine whether to replace the NOx gas sensor 3 based on the sensor replacement signal. However, the gas sensor control device 2 itself may detect the replacement of the NOx gas sensor 3. For example, the NOx gas sensor 3 includes an identification number (for example, a serial number) for identifying each NOx gas sensor, and the NOx gas sensor 3 indicates the identification number at the timing when the NOx gas sensor 3 is connected to the gas sensor control device 2. Information may be transmitted to the gas sensor control device 2, and the gas sensor control device 2 may store the received identification number. Thereby, the gas sensor control device 2 detects whether or not the NOx gas sensor has been replaced by collating the identification number stored in the gas sensor control device 2 with the identification number received from the NOx gas sensor 3 at the connected timing. be able to.

1 is a configuration diagram showing a schematic configuration of a gas detection device 1. FIG. 3 is a front view of a male connector 51 showing an arrangement of a semiconductor recording medium 6. FIG. 3 is a front view of a female connector 51 showing the arrangement of a semiconductor recording medium 6. FIG. 1 is a configuration diagram showing an internal configuration of a gas detection device 1. FIG. It is a flowchart which shows the sensor characteristic information acquisition process of 1st Embodiment. It is a flowchart which shows a gas concentration calculation process. It is a flowchart which shows the sensor characteristic information acquisition process of 2nd Embodiment. It is a flowchart which shows the backup invalid determination processing of 2nd Embodiment. It is a flowchart which shows the sensor characteristic information acquisition process of 3rd Embodiment. It is a flowchart which shows the backup invalid determination processing of 3rd Embodiment. It is a flowchart which shows a backup process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Gas detection apparatus, 2 ... Gas sensor control apparatus, 3 ... NOx gas sensor, 4,5 ... Connection cable, 6 ... Semiconductor recording medium, 31 ... NOx gas sensor element, 41, 51 ... Connector, 111 ... 1st pump cell, 112 ... oxygen partial pressure detection cell, 113 ... second pump cell, 118 ... reference oxygen chamber, 121 ... first porous electrode, 123 ... detection porous electrode, 125 ... second porous electrode, 131 ... first solid electrolyte layer 135, first electrode for first pump, 137, second electrode for first pump, 141, second solid electrolyte layer, 145, first electrode for second pump, 147, second electrode for second pump, 151 ... solid electrolyte layer for detection, 155 ... electrode for detection, 157 ... reference electrode, 159 ... first measurement chamber, 161 ... second measurement chamber, 191 ... CPU, 192 ... RAM, 193 ... ROM, 194 ... EE ROM, 195 ... signal input and output unit

Claims (5)

A sensor control device that includes a nonvolatile or volatile first storage medium to which electric power is constantly supplied and that detachably mounts a gas sensor that outputs a concentration signal corresponding to the concentration of a specific gas component, and controls the gas sensor. And
The first storage medium has a concentration calculation setting value set for each gas sensor in order to calculate the concentration of the specific gas component from the concentration signal, and a first concentration calculation setting value for the gas sensor. Pre-stored,
A non-volatile or volatile second storage medium to which power is always supplied;
First information acquisition means for acquiring the first concentration calculation setting value from the first storage medium;
Information storage means for storing the first concentration calculation setting value acquired by the first information acquisition means in the second storage medium as a second concentration calculation setting value;
Concentration calculating means for calculating the concentration of the specific gas component from the concentration signal using the concentration calculation setting value;
First acquisition determination means for determining whether or not acquisition of the first concentration calculation setting value by the first information acquisition means has succeeded,
The concentration calculating means includes
When the first acquisition determination unit determines that the acquisition of the first concentration calculation setting value is successful, the concentration calculation is performed using the first concentration calculation setting value acquired by the first information acquisition unit. When the first acquisition determining means determines that the acquisition of the first concentration calculation setting value has not been successful, the second concentration already stored in the second storage medium The sensor control device, wherein the concentration of the specific gas component is calculated from the concentration signal using the calculation setting value as the concentration calculation setting value. A non-volatile or volatile third storage medium to which power is always supplied, which stores a preset standard concentration calculation setting value that is not set for each gas sensor as the concentration calculation setting value;
Second information acquisition means for acquiring the second concentration calculation setting value from the second storage medium;
Second acquisition determination means for determining whether or not acquisition of the second concentration calculation setting value by the second information acquisition means has succeeded,
The concentration calculating means includes
In the case where the first acquisition determining unit determines that the acquisition of the first concentration calculation setting value is not successful, the second acquisition determining unit further determines that the acquisition of the second concentration calculation setting value is successful. If the second concentration acquisition setting value acquired by the second information acquisition unit is used as the concentration calculation setting value, the acquisition of the second concentration calculation setting value is not successful. If determined by the second acquisition determining means, the standard concentration calculation setting value stored in the third storage medium is used as the concentration calculation setting value, and the specific gas component is calculated from the concentration signal. The sensor control apparatus according to claim 1, wherein the concentration is calculated. A non-volatile or volatile third storage medium to which power is always supplied, which stores a preset standard concentration calculation setting value that is not set for each gas sensor as the concentration calculation setting value;
An exchange condition establishment judging means for judging whether or not a preset sensor exchange condition indicating that the gas sensor connected to the sensor control device needs to be exchanged is established,
The concentration calculating means includes
When the first acquisition determining means determines that the acquisition of the first concentration calculation setting value has not been successful, the replacement condition establishment determining means determines that the sensor replacement condition is not satisfied. In some cases, when the second condition calculation setting value stored in the second storage medium is used as the density calculation setting value and the sensor replacement condition is determined to be satisfied by the replacement condition satisfaction determination means, The concentration of the specific gas component is calculated from the concentration signal using the standard concentration calculation setting value stored in the third storage medium as the concentration calculation setting value. The sensor control device described. A non-volatile or volatile third storage medium to which power is always supplied, which stores a preset standard concentration calculation setting value that is not set for each gas sensor as the concentration calculation setting value;
Sensor replacement determination means for determining whether or not the gas sensor connected to the sensor control device has been replaced;
The concentration calculating means includes
When it is determined by the first acquisition determining means that the acquisition of the first concentration calculation setting value has not been successful, the sensor replacement determining means determines that the gas sensor has not been replaced. Using the second concentration calculation setting value stored in the second storage medium as the concentration calculation setting value, when the sensor replacement determination means determines that the gas sensor has been replaced, the third storage medium stores The sensor control apparatus according to claim 1, wherein the concentration of the specific gas component is calculated from the concentration signal using the stored standard concentration calculation setting value as the concentration calculation setting value. The gas sensor
It has a first measurement chamber and a second measurement chamber, at least a part of which is formed of one or more solid electrolyte bodies, and the oxygen concentration of the gas to be measured flowing from the first measurement chamber into the second measurement chamber Oxygen is pumped out or pumped in using the first oxygen pumping cell provided in the first measurement chamber so as to have a constant concentration, and oxygen is dissociated from the second measurement chamber to generate oxygen. The concentration of a specific gas component is detected by pumping out oxygen from the second measurement chamber using a second oxygen pumping cell in the second measurement chamber. The sensor control device according to 1.