JP2015034490A - Control device of oxygen sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate an accurate correction coefficient without applying an unnecessary load to a control device without affected by a state of an internal combustion engine.SOLUTION: A control device 16 of an oxygen sensor calculating a correction coefficient of an actual oxygen sensor 19 on the basis of an output average value of a reference oxygen sensor and an output average value of the actual oxygen sensor 19, includes a period changing portion 21 detecting exhaust pulsation of an internal combustion engine 1 during fuel cut control of the internal combustion engine 1 and changing an operation period of an output value of the actual oxygen sensor 19 on the basis of the exhaust pulsation, and an average value calculating portion measuring the output value of the actual oxygen sensor 19 on the basis of the changed operation period, and determining an output average value of the actual oxygen sensor 19.

Description

  The present invention relates to an oxygen sensor control apparatus, and more particularly to an oxygen sensor control apparatus capable of accurately calculating a correction coefficient for correcting an output value of an actual oxygen sensor provided in an exhaust passage of an internal combustion engine.

Conventionally, in a fuel injection control device for an internal combustion engine, the oxygen concentration in the exhaust gas is detected by an oxygen sensor installed in the exhaust passage, and the result is reflected in the air-fuel ratio control of the fuel mixture to improve the control accuracy. I am trying. If the output value of the oxygen sensor varies or changes in characteristics due to deterioration over time, the accuracy of the air-to-air ratio control is affected.
In order to prevent this, an actual oxygen sensor (hereinafter referred to as “actual oxygen sensor”) installed in the exhaust passage based on the output value of a reference oxygen sensor (hereinafter referred to as “reference oxygen sensor”). A method for correcting the output value has been devised (see FIG. 12). In FIG. 12, the output value of the reference oxygen sensor is measured and recorded in advance under atmospheric pressure, the output value of the actual oxygen sensor installed in the exhaust passage is measured under atmospheric pressure, and the output value of the reference oxygen sensor is used as a basis. In addition, a correction coefficient for correcting the output value of the actual oxygen sensor is calculated.
For example, Patent Document 1 discloses a technique that uses an output value of an oxygen sensor during fuel cut control of an internal combustion engine. In the control device of this Patent Document 1, it is assumed that the atmosphere in the exhaust passage during fuel cut control is in a state equivalent to atmospheric pressure, and the output value during fuel cut control previously measured by a reference oxygen sensor attached to the exhaust passage. As a reference, the correction coefficient of the output value of the actual oxygen sensor is calculated from the output value during the fuel cut control of the actual oxygen sensor when the engine is used.

However, since the oxygen sensor detects the oxygen concentration in the exhaust gas with the current output required for oxygen pumping into the detection chamber inside the sensor, the detected output value is affected by the pressure in the exhaust passage. Become. This effect is increased in a region greatly deviating from the stoichiometric state in which the oxygen pumping action is increased, which is, for example, during fuel cut control (see FIG. 13). In FIG. 13, during the fuel cut control, the air-fuel ratio becomes lean and the output value of the oxygen sensor increases. When the air-fuel ratio becomes lean, the output value of the oxygen sensor largely fluctuates due to pressure pulsation in the exhaust passage (hereinafter referred to as “exhaust pulsation”). This exhaust pulsation changes according to the crank rotational speed of the internal combustion engine.
Thus, when calculating the correction coefficient based on the output value of the actual oxygen sensor measured in the state during the fuel cut control, the correction coefficient calculated due to the influence of exhaust pulsation may vary.
Therefore, in the above-described conventional control device, processing such as averaging only the output value of the actual oxygen sensor measured during the fuel cut control within a predetermined range is performed to stabilize the calculated correction coefficient. ing.

JP 2011-149423 A

However, the exhaust pulsation that causes fluctuations in the output value of the actual oxygen sensor is caused by the pumping action by the piston of the internal combustion engine, and the pulsation cycle is inversely proportional to the crank rotation speed (proportional to the crank rotation period). The higher the is, the shorter the interval at which pulsation occurs (see FIG. 14). Further, since the pressure in the exhaust passage itself increases as the crank rotation speed increases, the output value (solid line) of the actual oxygen sensor also increases as the crank rotation speed increases as shown in FIG. And the error range (broken line) becomes smaller.
Thus, for example, when the output value calculation process is performed at a constant cycle, there is a problem that the pulsation state cannot be detected in a state where the crank rotation speed is high, and the processed output average value deviates from the original value. . In addition, since the pressure in the exhaust passage increases as the crank rotation speed increases, the error range of the output value changes according to the crank rotation speed if batch calculation processing is performed in all rotation speed regions. Therefore, there is a problem that the correction coefficient cannot be calculated accurately (see FIG. 15).

Furthermore, when the crank rotational speed is low, there is a problem that a load is imposed on the control device by performing processing at an unnecessary calculation cycle (see FIG. 16). In FIG. 16A, the crank rotation speed is low and the exhaust pulsation cycle is long. In FIG. 16B, the crank rotation speed is high and the exhaust pulsation cycle is short.
In FIG. 16A, since the pulsation cycle is long, an accurate output average value can be easily obtained if the calculation cycle is ½ or less of one cycle of exhaust pulsation. On the other hand, if the calculation cycle becomes excessively short, unnecessary calculations increase and an extra load is applied to the control device. In FIG. 16 (a), four calculations (indicated by circles) are performed per cycle of exhaust pulsation, and the output average value can be calculated accurately, but the load applied to the control device is large. is there.
On the other hand, in FIG. 16B, the pulsation period and the calculation period are substantially the same. In this state, the time indicated by the circles in the pulsation cycle is small, the number of output values is insufficient, and an accurate output average value cannot be calculated.

  Therefore, in the present invention, the measurement mode is divided for each crank rotation speed, and the final correction coefficient is calculated based on the original correction coefficient calculated at an appropriate calculation cycle for each measurement mode. An object of the present invention is to enable accurate calculation of the correction coefficient without being affected by the state of the internal combustion engine and without placing an unnecessary burden on the control device.

  The present invention provides a control device for an oxygen sensor that calculates a correction coefficient of the actual oxygen sensor based on an output average value of a reference oxygen sensor and an output average value of the actual oxygen sensor, and the internal combustion engine during fuel cut control of the internal combustion engine. An exhaust pulsation of the actual oxygen sensor, and a cycle changing unit that changes a calculation cycle of the output value of the actual oxygen sensor according to the exhaust pulsation, and an output value of the actual oxygen sensor is measured based on the changed calculation cycle. And an average value calculation unit for obtaining an average output value of the actual oxygen sensor.

  In the present invention, when calculating the correction coefficient of the actual oxygen sensor, the output value of the actual oxygen sensor is measured according to the exhaust pulsation to obtain the output average value. Therefore, according to the present invention, the correction coefficient of the actual oxygen sensor can be accurately calculated without being affected by the state of the internal combustion engine.

FIG. 1 is a system configuration diagram of an oxygen sensor control apparatus. (Example). FIG. 2 is a flowchart for calculating the correction coefficient. (Example) FIG. 3 is a flowchart of timing control. (Example) FIG. 4 is a diagram showing the setting of the measurement mode. (Example) FIG. 5 is a diagram showing information defined in the measurement mode. (Example) FIG. 6 is a flowchart for calculating the output average value of the actual oxygen sensor. (Example) FIG. 7 is a time chart for calculating the average output value of the actual oxygen sensor. (Example) FIG. 8 is a diagram showing the relationship between the calculation cycle and the calculation time. (Example) FIG. 9 is a flowchart for updating the correction coefficient of the actual oxygen sensor. (Example) FIG. 10A is a diagram showing an output value calculation cycle when the exhaust pulsation cycle is long, and FIG. 10B is a diagram showing an output value calculation cycle when the exhaust pulsation cycle is short. (Example) FIG. 11 is a diagram showing correction coefficients calculated for each crank rotation speed in the measurement mode based on the output average value of the reference oxygen sensor and the output average value of the actual oxygen sensor. (Example) FIG. 12 is a diagram showing correction coefficients calculated based on the output value of the reference oxygen sensor and the output value of the actual oxygen sensor. (Conventional example) FIG. 13 is a diagram showing fluctuations in the output value of the actual oxygen sensor due to exhaust pulsation. (Conventional example) FIG. 14 is a graph showing the relationship between the crank rotation speed and the exhaust pulsation cycle. (Conventional example) FIG. 15 is a diagram showing a change in output characteristics of the actual oxygen sensor during fuel cut control of the internal combustion engine. (Conventional example) FIG. 16A is a diagram showing an output value calculation cycle when the exhaust pulsation cycle is long, and FIG. 16B is a diagram showing an output value calculation cycle when the exhaust pulsation cycle is short. (Conventional example)

  Embodiments of the present invention will be described below with reference to the drawings.

1 to 11 show an embodiment of the present invention. In FIG. 1, the internal combustion engine 1 includes four cylinders 2, and an air cleaner 3, an intake pipe 4, a throttle body 5, a surge tank 6, and an intake manifold 7 are sequentially connected, and intake air supplied to each cylinder 2 flows. An intake passage 8 is provided. The throttle body 5 is provided with a throttle valve 9. The intake manifold 7 includes a fuel injection valve 10 that injects fuel for each cylinder 2. The internal combustion engine 1 further includes an exhaust passage 15 that sequentially connects an exhaust manifold 11, a front exhaust pipe 12, a catalyst 13, and a rear exhaust pipe 14 and through which exhaust gas discharged from each cylinder 2 flows.
The fuel injection valve 10 is connected to a control device 16. As a means for inputting control information to the control device 16, a crank angle sensor 17 for calculating the rotational speed (crank rotational speed) of the crankshaft of the internal combustion engine 1 and an intake air for detecting the intake pipe pressure of the intake pipe 4. An actual oxygen sensor (hereinafter referred to as “actual oxygen sensor”) installed in the front exhaust pipe 12 in order to detect the oxygen concentration in the exhaust gas flowing through the pipe pressure sensor 18 and the exhaust passage 15 upstream of the catalyst 13. 19 is connected.
The control device 16 controls the injection amount of the fuel injection valve 10 so as to cause the internal combustion engine 1 to generate the driving force requested by the driver based on the information input from these sensors 17 to 19, and the fuel cut condition is When it is established, control is performed so as to stop the injection of the fuel injection valve 10.

The control device 16 detects the oxygen concentration in the exhaust gas by the actual oxygen sensor 19 and reflects the detection result in the air-fuel ratio control of the internal combustion engine 1 to improve the control accuracy. The control device 16 calculates the correction coefficient because the output value indicating the oxygen concentration of the actual oxygen sensor 19 has an influence on the accuracy of the air-to-air ratio control when variations or characteristic changes due to deterioration with time occur. The output value is corrected.
The control device 16 measures the output value of the reference oxygen sensor (hereinafter referred to as “reference oxygen sensor”) in advance under atmospheric pressure, stores the output average value, and the actual oxygen sensor 19 installed in the exhaust passage 15. Is measured under atmospheric pressure to calculate an average output value, and the output value of the actual oxygen sensor 19 is corrected based on the stored average output value of the reference oxygen sensor and the average output value of the actual oxygen sensor 19. A correction coefficient is calculated.
For this reason, the control device 16 includes a timing control unit 20, a period changing unit 21, an average value calculating unit 22, a sensor correcting unit 23, and a storage unit 24.
The timekeeping control unit 20 measures the elapsed time after the start of the fuel cut by the timer during the fuel cut control of the internal combustion engine 1, and determines whether the elapsed time has become a set value or more. The set value is the time until the exhaust pipe pressure reaches atmospheric pressure after the start of fuel cut.
The cycle changing unit 21 detects the exhaust pulsation of the exhaust passage 15 during the fuel cut control of the internal combustion engine 1, and changes the calculation cycle of the output value of the actual oxygen sensor 19 according to the exhaust pulsation. The cycle changing unit 21 changes the calculation cycle to be shorter as the exhaust pulsation cycle is shorter. The exhaust pulsation in the exhaust passage 15 is estimated from the crank rotational speed using the intake pipe pressure of the intake pipe 4 detected by the intake pipe pressure sensor 18. The exhaust pulsation can also be obtained from the exhaust pipe pressure of the exhaust passage 15 detected by the exhaust pipe pressure sensor provided in the front exhaust pipe 12.
The average value calculation unit 22 measures the output value of the actual oxygen sensor 16 based on the calculation cycle changed by the cycle changing unit 21 and obtains the output average value of the actual oxygen sensor 19.
The sensor correction unit 23 calculates and updates a correction coefficient based on the average output value of the actual oxygen sensor 19 calculated by the average value calculation unit 22.
The storage unit 24 stores an output value of the reference oxygen sensor, a correction coefficient of the actual oxygen sensor 19, a correspondence table between the crank rotation speed and the measurement mode, and measurement mode information. Further, the storage unit 24 stores an average output value of the reference oxygen sensor according to the cycle of the exhaust pulsation. The sensor correction unit 23 uses the average output value of the reference oxygen sensor according to the exhaust pulsation period when calculating the correction coefficient of the actual oxygen sensor 19.

Next, the operation will be described.
As shown in FIG. 2, when the control program is started (100), the control device 16 of the actual oxygen sensor 19 executes time control by the time control unit 20 (200).
The timekeeping control (200) is executed to delay the acquisition of the output value of the actual oxygen sensor 19 until the exhaust pipe pressure reaches the atmospheric pressure after the fuel cut control is started. In this timing control (200), when the output value of the actual oxygen sensor 16 is acquired immediately after the fuel cut control is started, the output value before the exhaust pipe pressure reaches the atmospheric pressure is acquired, thereby preventing an error from occurring. This is the control to be performed.

In the timing control (200), as shown in FIG. 3, when the control program starts (201), it is determined whether the internal combustion engine 1 is under fuel cut control (202). If this determination (202) is NO, this determination (202) is repeated. If this determination (202) is YES, the elapsed time of the timer after the start of fuel cut is added (203), and it is determined whether the elapsed time by the timer is equal to or greater than the set value TFC (elapsed time ≥ set value TFC). (204).
If the determination (204) is NO, the process returns to the determination (202). If this determination (204) is YES, the process returns (205).

In the timekeeping control (200), when the elapsed time is equal to or greater than the set value TFC, the measurement mode is set (300). In the measurement mode setting (300), the crank rotation speed is acquired, and the measurement mode is set according to the crank rotation speed.
As shown in FIG. 4, the measurement mode is set in advance according to the crank rotation speed. For example, when the crank rotation speed is between NEL_n and NEH_n (crank rotation speed range), the measurement mode M_n is selected.
However, when the crank rotational speed is between NEL_n and NEHn-1, M_n-1 which is the measurement mode on the lower crank rotational speed side is selected. This is because the crank rotational speed during the fuel cut control tends to decrease, so that the low measurement mode is selected even at the crank rotational speed at which the value of the output value calculation cycle Tip_x should be increased. ing.
Thereby, the calculation cycle Tip_x corresponding to the crank rotation speed region is set with high accuracy. The cycle changing unit 21 changes the setting of the calculation cycle Tip_x in accordance with the crank rotation speed region.

After the setting of the measurement mode (300), the average value calculation unit 22 calculates the output average value IPave_x of the actual oxygen sensor 19 based on the set measurement mode (400).
In the measurement mode, as shown in FIG. 5, each information of a calculation cycle, a crank rotation speed range, an intake pipe pressure range, and an output average value of the reference oxygen sensor is defined in advance for each measurement mode M_1 to M_n. Yes. Each information of these measurement modes is stored in the storage unit 24.
In the calculation (400) of the output average value IPave_x of the actual oxygen sensor 19, as shown in FIG. 6, when the calculation program starts (401), the crank rotational speed is set in the measurement mode setting (300). It is determined whether or not the rotational speed range (NEL_x <crank rotational speed ≦ NEH_x) defined by the mode (402), and the intake pipe defined by the measurement mode set in the measurement mode setting (300) It is determined whether the pressure is within the pressure range (PBL_x <intake pipe pressure ≦ PBH_x) (403).
If the determination (402) is NO, and if the determination (403) is NO, an incorrect output average value IPave_x may be calculated, so the program is ended (404). When both the determination (402) and the determination (403) are YES, the calculation time Tip is started, and the calculation period is determined by the measurement mode set in the measurement mode setting (300). It is determined whether or not Tip_x or more (Tip ≧ Tip_x) (405).
If this determination (405) is NO, the process returns to determination (402). If the determination (405) is YES, the calculation time Tip is reset to 0 (406), the output value IP_x of the actual oxygen sensor 19 is measured (407), and the output average value IPave_x of the actual oxygen sensor 19 is calculated. (408) The number of measurements of the output value IP_x of the actual oxygen sensor 19 is counted up (409), and it is determined whether the number of measurements is equal to or greater than the set value Cip (measurement count ≧ Cip) (410).
If this determination (410) is NO, the process returns to determination (402). If this determination (410) is YES, the process proceeds to calculation (500) of the correction coefficient Kip_x in FIG. 2 (411).

In the calculation (400) of the average output value IPave_x of the actual oxygen sensor 19, as shown in FIG. 7, when the elapsed time after starting the fuel cut control becomes equal to or greater than the set value TFC, the measurement is performed based on the crank rotation speed. Mode M_x is set. After the measurement mode M_x is determined, it is determined whether or not the crank rotation speed and the intake pipe pressure are in a range corresponding to the measurement mode M_x.
When the crank rotation speed and the intake pipe pressure are in the ranges (NEL_x · NEH_x, PBL_x · PBH_x) corresponding to the measurement mode M_x, the output value of the actual oxygen sensor 16 is based on the calculation cycle Tip_x set in the measurement mode M_x. IP_x is acquired, and the output average value IPave_x is calculated. On the other hand, when at least one of the crank rotation speed and the intake pipe pressure is out of the range corresponding to the measurement mode M_x, the calculation of the output average value IPave_x is stopped.
As shown in FIG. 8, the calculation time Tip_x is reset when the calculation time Tip is equal to or longer than the calculation cycle Tip_x defined by the measurement mode M_x.
In calculating the output average value IPave_x of the actual oxygen sensor 19, for example,
IPave_x (n) = IPave_x (n−1) * α + IP_x * (1−α)
It can be calculated by the following formula. In addition, regarding the set value Cip of the number of times of measurement, the calculation cycle Tip_x is changed according to the crank rotation speed, so that it does not depend on the crank rotation speed and is set to a constant rotation speed (for example, about 256 times). it can.

As shown in FIG. 2, after calculating (400) the output average value IPave_x of the actual oxygen sensor 19, the sensor correction unit 22 calculates the correction coefficient Kip_x based on the calculated output average value IPave_x of the actual oxygen sensor 19. Calculate (500), and update the calculated correction coefficient Kip_x (600).
In the calculation (500) of the correction coefficient Kip_x, from the output average value IPrav_x of the reference oxygen sensor and the output average value IPave_x of the actual oxygen sensor 19,
Kip_x = IPrave_x / IPave_x
Calculate with the following formula.
In the update (600) of the correction coefficient Kip_x, as shown in FIG. 9, when the update program starts (601), the ratio (Kip_x / Kip) of the correction coefficient Kip_x calculated this time to the previous correction coefficient Kip is the lower limit. It is determined whether the value is in the range greater than or equal to value A and less than the upper limit value B (A ≦ Kip_x / Kip <B) (602).
If this determination (602) is YES,
Kip (n) = Kip (n−1) * α + Kip_x (n) * (1−α)
From the previous correction coefficient Kip (n−1) and the currently calculated correction coefficient Kip_x (n), the current correction coefficient Kip (n) is obtained (603), and the previous correction coefficient Kip (n−1) is obtained. ) Is updated to Kip (n), and the update ends (604).
If the determination (602) is NO, the correction coefficient Kip_x is reset (605), and the update is ended (604).
After the correction coefficient Kip_x is updated (600), as shown in FIG. 2, the process returns to the time counting control (200) (700).
The reference oxygen used in each of the steps (100) to (700) of FIG. 2 described above according to the correspondence table between the crank rotation speed and the measurement mode, the measurement mode information, the output value of the reference oxygen sensor, and the exhaust pulsation cycle. The sensor output average value and the correction coefficient of the actual oxygen sensor 19 are stored in the storage unit 24.

FIG. 10 shows a calculation cycle when the control by the control device 16 of the actual oxygen sensor 19 is applied. When the crank rotation speed is low and the exhaust pulsation cycle is long (see FIG. 10A), the control device 16 sets the calculation cycle to be long. On the other hand, when the crank rotational speed is high and the exhaust pulsation cycle is short (see FIG. 10B), the control device 16 sets the calculation cycle short.
Thereby, the control device 16 of the actual oxygen sensor 19 can reduce the calculation load of the control device 16 in the region where the crank rotation speed shown in FIG. 10A is low, and the crank rotation shown in FIG. In the region where the speed is high, the output value of the actual oxygen sensor 19 is accurately measured, and the calculation accuracy of the correction coefficient can be improved.
Further, as shown in FIG. 11, the control device 16 of the actual oxygen sensor 19 calculates a correction coefficient Kip_x from the output average value IPave_x of the reference oxygen sensor and the output average value IPave_x of the actual oxygen sensor 19 for each measurement zone M_x. To do. Thereby, the difference in the output value of the actual oxygen sensor 19 for each crank rotation speed can be absorbed, and an accurate correction coefficient Kip_x can be calculated.

As described above, when calculating the correction coefficient Kip_x of the actual oxygen sensor 19, the control device 16 of the actual oxygen sensor 19 measures the output value IP_x of the actual oxygen sensor 19 according to the exhaust pulsation to obtain the output average value IPave_x. ing.
Therefore, the control device 16 of the actual oxygen sensor 19 calculates the correction coefficient Kip_x of the actual oxygen sensor 19 when calculating the correction coefficient Kip_x from the output average value IPave_x of the reference oxygen sensor and the output average value IPave_x of the actual oxygen sensor 19. Can be accurately calculated without being affected by the state of the internal combustion engine 1.
Further, the control device 16 of the actual oxygen sensor 19 includes a storage unit 24 that stores the output average value IPrav_x of the reference oxygen sensor in accordance with the cycle of the exhaust pulsation. When calculating the correction coefficient Kip_x of the actual oxygen sensor 19, the control device 16 uses the average output value IPrav_x of the reference oxygen sensor corresponding to the cycle of the exhaust pulsation.
In this way, the control device 16 of the actual oxygen sensor 19 uses the output average value IPrav_x of the reference oxygen sensor determined in advance according to the exhaust pulsation when calculating the correction coefficient Kip_x of the actual oxygen sensor 19, so that the internal combustion engine Whatever the state of the engine 1, the correct correction coefficient Kip_x can be calculated.
Further, the control device 16 of the actual oxygen sensor 19 changes the calculation cycle shorter by the cycle changing unit 21 as the exhaust pulsation cycle is shorter.
As a result, when the exhaust pulsation cycle is long, the control device 16 of the actual oxygen sensor 19 does not measure an excessively large output value because the calculation cycle also becomes long. Therefore, the control device 16 can eliminate the need to perform unnecessary output value calculation processing. On the other hand, when the exhaust pulsation is short, the control device 16 has a short calculation cycle. That is, the control device 16 can prevent an incorrect correction coefficient Kip_x from being calculated because the number of output value measurements of the actual oxygen sensor 19 per certain period increases.

In the internal combustion engine 1, the width of the pressure pulsation in the exhaust passage 15 becomes smaller as the crank rotational speed becomes higher, so that the influence of the pressure pulsation on the output of the actual oxygen sensor 19 is sufficiently small. When the correction coefficient calculation process is permitted, accurate correction coefficient calculation is possible even when the processing cycle is long.
Further, when the internal combustion engine 1 is frequently used in a region where the crank rotational speed is low, the output measurement of the actual oxygen sensor 19 in the high rotational speed region is prohibited, so that the sensor output measurement can be performed at a uniform long cycle. It is possible to calculate an accurate correction coefficient.

  The present invention is capable of accurately calculating the correction coefficient of the actual oxygen sensor without being affected by the state of the internal combustion engine 1, and is a sensor characteristic deviation diagnostic device that uses the sensor output at the time of fuel cut. Also available.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 8 Intake passage 10 Fuel injection valve 15 Exhaust passage 16 Control apparatus 17 Crank angle sensor 18 Intake pipe pressure sensor 19 Actual oxygen sensor 20 Timekeeping control part 21 Period change part 22 Average value calculation part 23 Sensor correction part 24 Storage part

Claims (3)

  In an oxygen sensor control device that calculates a correction coefficient of the actual oxygen sensor based on an output average value of a reference oxygen sensor and an output average value of an actual oxygen sensor, exhaust pulsation of the internal combustion engine is reduced during fuel cut control of the internal combustion engine. Detecting and changing a calculation cycle of the output value of the actual oxygen sensor according to the exhaust pulsation, and measuring an output value of the real oxygen sensor based on the changed calculation cycle, An oxygen sensor control device comprising: an average value calculation unit for obtaining an output average value of the sensor.   A storage unit that stores an average output value of the reference oxygen sensor according to the cycle of the exhaust pulsation, and when calculating a correction coefficient of the actual oxygen sensor, the reference oxygen sensor according to the cycle of the exhaust pulsation The oxygen sensor control device according to claim 1, wherein an output average value is used.   The oxygen sensor control device according to claim 1, wherein the cycle changing unit changes the calculation cycle to be shorter as the exhaust pulsation cycle is shorter.

Images