JP2021038742A - State determination device of internal combustion engine, state determination system of internal combustion engine, data analysis device, and control device of internal combustion engine - Google Patents

Abstract

To provide a state determination device of an internal combustion engine capable of reducing a calculation load by mapping to a CPU, in a case when a rotating speed of a crank shaft is high.SOLUTION: A state determination device of an internal combustion engine includes: a storage device inputting an internal combustion engine state variable as a parameter indicating a state of the internal combustion engine and storing a mapping data as a data to define a map outputting a result of the determination of the state of the internal combustion engine; and an execution device executing an acquisition processing for acquiring the internal combustion engine state variable every rotation of a crank shaft of the internal combustion engine by a prescribed angle, and a determination processing for determining the state of the internal combustion engine on the basis of the output of the map by inputting the internal combustion engine state variable. A CPU determines whether a rotating speed NE of the crank shaft is less than a predetermined prescribed rotating speed NEth or not (S13), determines whether an execution flag is ON or not in a case when the rotating speed NE is the predetermined prescribed rotating speed NEth or more (S13:NO), and omits the determination processing (S14, S16) when the execution flag is OFF (S17:NO).SELECTED DRAWING: Figure 2

Description

The present invention relates to an internal combustion engine state determination device, an internal combustion engine state determination system, a data analysis device, and an internal combustion engine control device.

In the misfire detection system described in Patent Document 1, time-series data of the rotation speed of the crankshaft of the internal combustion engine sampled at a predetermined cycle is input to the input layer, and information on the cylinder in which the misfire has occurred is output from the output layer. A hierarchical neural circuit model constructed in is used. The hierarchical neural circuit model is supervised and learned.

Japanese Unexamined Patent Publication No. 4-91348

In a misfire detection system as described in Patent Document 1, the higher the rotation speed of the crankshaft, the higher the frequency of detecting misfire. Therefore, when the rotation speed of the crankshaft is high, the calculation load on the device by the hierarchical neural circuit model may increase. It should be noted that the same problem may occur not only in the detection of misfire but also in the case of detecting and calculating each time the crankshaft rotates by a specified angle using a hierarchical neural circuit model.

Hereinafter, means for solving the above problems and their actions and effects will be described.
1. 1. The storage device includes a storage device and an execution device, and the storage device is data that defines a mapping that outputs a determination result of the state of the internal combustion engine by inputting an internal combustion engine state variable which is a parameter indicating the state of the internal combustion engine. The execution device stores the mapping data, and the executing device acquires the internal combustion engine state variable every time the crank shaft of the internal combustion engine rotates by a predetermined angle, and outputs the mapping using the internal combustion engine state variable as an input. Based on the above, a determination process for determining the state of the internal combustion engine is executed, the mapping data is data that has been learned by machine learning, and the execution device sets the rotational speed of the crank shaft to be equal to or higher than a predetermined threshold value. This is a state determination device for an internal combustion engine that omits a part of the determination process for each rotation of the specified angle.

According to the above configuration, when the rotation speed of the crankshaft exceeds a predetermined threshold value, the determination process is executed less frequently by omitting a part of the determination process for each degree of rotation by a predetermined angle. Become. Compared with the case where the determination processing is performed without changing the frequency, the calculation load of the execution device is reduced. Therefore, it is not necessary to adopt a high-performance and high-cost execution device assuming that the rotation speed of the crankshaft is high.

2. The internal combustion engine is provided with a plurality of cylinders, and the state of the internal combustion engine is a variation in the air-fuel ratio among the plurality of cylinders. When it is determined that the data is present, a coping process for dealing with a large variation in the air-fuel ratio is executed by operating a predetermined hardware, and the mapping data is a rotation waveform variable and a plurality of first intervals. Actually when the fuel injection valve is operated to control the air-fuel ratio of the air-fuel mixture in each of a plurality of cylinders to the same air-fuel ratio by inputting the air-fuel ratio detection variable which is a variable corresponding to the output of the air-fuel ratio sensor in each It defines a mapping that outputs an imbalance variable, which is a variable indicating the degree of variation between the air-fuel ratios of the air-fuel ratio, and the execution device uses the detection value of the sensor that detects the rotational behavior of the crank shaft in the acquisition process. Based on the rotation waveform variable and the air-fuel ratio detection variable at each of the plurality of first intervals, the rotation waveform variable is a variable corresponding to the rotation speed of the crank shaft at each of the plurality of second intervals. It is a variable indicating the difference between the variables, and the first interval and the second interval are both angular intervals of the crank shaft smaller than the appearance interval of the compression top dead point, and the rotation used as the input of the mapping. The state determination device for an internal combustion engine according to 1 above, wherein the waveform variable and the plurality of the air-fuel ratio detection variables are time-series data within a predetermined angular interval larger than the appearance interval, respectively.

According to the above configuration, the state determination device of the internal combustion engine can be applied to determine the variation in the air-fuel ratio among a plurality of cylinders as the state of the internal combustion engine. Then, when it is determined that the air-fuel ratio varies between cylinders, it is possible to execute a coping process for the variation.

3. 3. The state of the internal combustion engine is the presence or absence of a misfire of the internal combustion engine, and when the executing device determines that a misfire has occurred by the determination process, it deals with the fact that the misfire has occurred by operating a predetermined hardware. The mapping data is input to time-series data which is an instantaneous speed parameter in each of a plurality of consecutive fourth intervals included in the third interval, and the probability that the internal combustion engine has misfired. The execution device acquires the instantaneous speed parameter based on the detection value of the sensor that detects the rotational behavior of the crankshaft of the internal combustion engine in the acquisition process, and the execution device acquires the instantaneous speed parameter. The parameters are parameters according to the rotation speed of the crankshaft of the internal combustion engine, the third interval is the rotation angle interval of the crankshaft and includes the compression top dead center, and the fourth interval is. The interval is smaller than the appearance interval of the compression top dead center, and the mapping outputs the probability that a misfire has occurred for at least one cylinder in which the compression top dead center appears within the third interval. 1. The state determination device for an internal combustion engine according to 1.

According to the above configuration, the state determination device of the internal combustion engine can be applied to determine the presence or absence of misfire of the internal combustion engine as the state of the internal combustion engine. Then, when it is determined that a misfire has occurred, it is possible to execute a coping process for the misfire.

4. The execution device and the storage device according to any one of the above 1 to 3 are provided, the execution device includes a first execution device and a second execution device, and the first execution device is mounted on a vehicle. Further, the acquisition process and the vehicle-side transmission process of transmitting the data acquired by the acquisition process to the outside of the vehicle are executed, and the second execution device is arranged outside the vehicle and It is a state determination system of an internal combustion engine that executes an external reception process for receiving data transmitted by the vehicle-side transmission process and the determination process. According to the above configuration, the calculation load of the in-vehicle device can be reduced by executing the determination process outside the vehicle.

5. A data analysis device including the second execution device and the storage device according to the above 4.
6. It is a control device of an internal combustion engine including the first execution device according to the above 4.

The figure which shows the structure of the control device and the drive system of a vehicle which concerns on 1st Embodiment. The flow chart which shows the procedure of the imbalance determination processing which concerns on the same embodiment. The flow chart which shows the procedure of the coping process which concerns on the same embodiment. The figure which shows the system which generates the mapping data which concerns on this embodiment. The flow chart which shows the procedure of the learning process of the mapping data which concerns on the same embodiment. (A) and (b) are diagrams showing the relationship between imbalance and 0.5th-order amplitude. The figure which shows the structure of the state determination system which concerns on 2nd Embodiment. (A) and (b) are flow charts showing the procedure of the determination process according to the same embodiment. The flow chart which shows the procedure of the misfire determination processing which concerns on 3rd Embodiment. The flow chart which shows the procedure of the coping process which concerns on the same embodiment.

<First Embodiment>
Hereinafter, the first embodiment of the internal combustion engine state determination device will be described with reference to the drawings.

In the internal combustion engine 10 mounted on the vehicle VC shown in FIG. 1, a throttle valve 14 is provided in the intake passage 12. The air sucked from the intake passage 12 flows into the combustion chambers 18 of the cylinders # 1 to # 4 by opening the intake valve 16. Fuel is injected into the combustion chamber 18 by the fuel injection valve 20. In the combustion chamber 18, the air-fuel mixture is subjected to combustion by spark discharge by the ignition device 22, and the energy generated by the combustion is taken out as the rotational energy of the crankshaft 24. The air-fuel mixture used for combustion is discharged to the exhaust passage 28 as exhaust gas when the exhaust valve 26 is opened. The exhaust passage 28 is provided with a three-way catalyst 30 having an oxygen storage capacity. The exhaust passage 28 is communicated with the intake passage 12 via the EGR passage 32. The EGR passage 32 is provided with an EGR valve 34 for adjusting the cross-sectional area of the flow path.

The rotational power of the crankshaft 24 is transmitted to the intake side camshaft 42 via the intake side valve timing variable device 40, while being transmitted to the exhaust side camshaft 46 via the exhaust side valve timing variable device 44. The intake side valve timing variable device 40 changes the relative rotational phase difference between the intake side cam shaft 42 and the crank shaft 24. The exhaust-side valve timing variable device 44 changes the relative rotational phase difference between the exhaust-side camshaft 46 and the crankshaft 24.

The input shaft 66 of the transmission 64 can be connected to the crankshaft 24 of the internal combustion engine 10 via a torque converter 60. The torque converter 60 includes a lockup clutch 62, and when the lockup clutch 62 is engaged, the crankshaft 24 and the input shaft 66 are connected to each other. Drive wheels 69 are mechanically connected to the output shaft 68 of the transmission 64.

A crank rotor 50 provided with a plurality of (here, 34) tooth portions 52 indicating the rotation angle of the crank shaft 24 is connected to the crank shaft 24. Although the crank rotor 50 is basically provided with tooth portions 52 at intervals of 10 ° CA, there is one missing tooth portion 54 at which the interval between adjacent tooth portions 52 is 30 ° CA. It is provided. This is for indicating the reference rotation angle of the crankshaft 24. A crank angle sensor 80 is installed in the vicinity of the crank rotor 50. The crank angle sensor 80 converts the change in magnetic flux according to the proximity and separation of the tooth portions 52 into a short wave pulse signal and outputs the signal. In the following description, the output signal of the crank angle sensor 80 will be referred to as a crank signal Scr. In the present embodiment, the crank angle sensor 80 corresponds to a sensor that detects the rotational behavior of the crankshaft 24.

The control device 70 targets the internal combustion engine 10 and controls the throttle valve 14, the fuel injection valve 20, the ignition device 22, the EGR valve 34, and the intake side in order to control the torque and the exhaust component ratio, which are the controlled amounts thereof. The valve timing variable device 40 and the exhaust side valve timing variable device 44 are operated. Note that FIG. 1 shows operation signals MS1 to MS6 of the throttle valve 14, the fuel injection valve 20, the ignition device 22, the EGR valve 34, the intake side valve timing variable device 40, and the exhaust side valve timing variable device 44, respectively. ing.

The control device 70 includes a crank signal Scr, which is an output signal of the crank angle sensor 80, which outputs a pulse for each angular interval (10 ° CA excluding the missing tooth portion 54) between the tooth portions 52 when controlling the control amount. Refer to the intake air amount Ga detected by the air flow meter 82. Further, the control device 70 has a water temperature THW which is an upstream detection value Afu detected by the air-fuel ratio sensor 83 provided on the upstream side of the three-way catalyst 30 and a cooling water temperature of the internal combustion engine 10 detected by the water temperature sensor 84. Refer to. Further, the control device 70 refers to the shift position Sft of the transmission 64 detected by the shift position sensor 86 and the vertical acceleration Dacc of the vehicle VC detected by the acceleration sensor 88.

The control device 70 includes a CPU 72, a ROM 74, a storage device 76 composed of an electrically rewritable non-volatile memory, and a peripheral circuit 77, which can be communicated by the local network 78. The peripheral circuit 77 includes a circuit that generates a clock signal that defines the internal operation, a power supply circuit, a reset circuit, and the like.

The control device 70 executes the control of the control amount by the CPU 72 executing the program stored in the ROM 74.
Further, the control device 70 performs a base injection amount calculation process for calculating a base injection amount which is a base value of the fuel amount for setting the air-fuel ratio of the air-fuel mixture in the combustion chamber 18 as the target air-fuel ratio based on the filling efficiency η. Do. The filling efficiency η is a parameter that determines the amount of air filled in the combustion chamber 18. Specifically, in the base injection amount calculation process, for example, when the filling efficiency η is expressed as a percentage, the filling efficiency η is multiplied by the fuel amount per 1% of the filling efficiency η for setting the air-fuel ratio as the target air-fuel ratio. Therefore, the process of calculating the base injection amount may be performed. The base injection amount is a fuel amount calculated to control the air-fuel ratio to the target air-fuel ratio based on the amount of air filled in the combustion chamber 18. Incidentally, the target air-fuel ratio may be, for example, the theoretical air-fuel ratio. Further, the control device 70 calculates the required injection amount Qd based on the base injection amount.

Then, the control device 70 determines the variation between the actual air-fuel ratios when the fuel injection valve is operated to control the air-fuel ratios of the air-fuel mixture in each of the plurality of cylinders of the internal combustion engine 10 to be equal to each other. To execute.

FIG. 2 shows the procedure of the imbalance determination process. The process shown in FIG. 2 is realized by the CPU 72 repeatedly executing the imbalance detection program 74a stored in the ROM 74 shown in FIG. 1, for example, at a predetermined cycle. In the following, the step number of each process is represented by a number prefixed with "S".

In the series of processes shown in FIG. 2, the CPU 72 first determines whether or not the execution condition of the imbalance detection process is satisfied (S10). The execution conditions include that the fuel vapor is not purged for the intake air of the internal combustion engine 10 and the exhaust gas is not recirculated.

Next, the CPU 72 has a minute rotation time T30 (1), T30 (2), ..., T30 (24), an upstream average value of Afave (1), Afave (2), ..., Afave (24), and a rotation speed NE. , Filling efficiency η, and 0.5th order amplitude Ampf / 2 are acquired (S12). The minute rotation time T30 is calculated by the CPU 72 measuring the time required for the crankshaft 24 to rotate 30 ° CA based on the crank signal Scr of the crank angle sensor 80. Here, when the numbers in parentheses are different, such as the minute rotation times T30 (1) and T30 (2), it indicates that they have different rotation angle intervals within 720 ° CA, which is one combustion cycle. That is, the minute rotation times T30 (1) to T30 (24) indicate the rotation times at each angle interval obtained by equally dividing the rotation angle region of 720 ° CA by 30 ° CA.

Specifically, the CPU 72 clocks the time when the crankshaft 24 rotates by 30 ° CA based on the crank signal Scr, and sets this as the pre-filtering time NF30. Next, the CPU 72 calculates the post-filter processing time AF30 by performing digital filter processing with the pre-filter processing time NF30 as an input. Then, the CPU 72 normalizes the post-filter processing time AF30 so that the difference between the maximum value and the minimum value of the post-filter processing time AF30 in a predetermined period (for example, 720 ° CA) is “1”, thereby causing the minute rotation time T30. Is calculated.

Further, assuming that m = 1 to 24, the upstream side average value Afuave (m) is the average value of the upstream side detection value Afu at the same angle interval of 30 ° CA as each of the minute rotation times T30 (m).

The rotation speed NE is calculated by the CPU 72 based on the crank signal Scr of the crank angle sensor 80, and the filling efficiency η is calculated by the CPU 72 based on the rotation speed NE and the intake air amount Ga. The rotation speed NE is an average value of the rotation speeds when the crankshaft 24 rotates at an angle interval larger than the appearance interval of the compression top dead center (180 ° CA in this embodiment). The rotation speed NE is preferably an average value of the rotation speeds when the crankshaft 24 rotates by a rotation angle of one rotation or more of the crankshaft 24. The average value here is not limited to the simple average, and may be, for example, exponential moving average processing. A plurality of sampling values such as, for example, a minute rotation time T30 when the crankshaft 24 rotates by a rotation angle of one rotation or more. It shall be calculated by.

The 0.5th-order amplitude Ampf / 2 is the intensity of the 0.5th-order component of the rotation frequency of the crankshaft 24, and is calculated by the CPU 72 by the Fourier transform of the time-series data of the minute rotation time T30.

Next, the CPU 72 determines whether or not the rotation speed NE is less than a predetermined predetermined rotation speed NEth (S13). Here, the predetermined rotation speed NEth is set as a value in which the load of the calculation process by the mapping data 76a, which will be described later, is correspondingly large with respect to the processing capacity of the CPU 72. Then, when the rotation speed NE is less than the predetermined rotation speed NEth (S13: YES), the CPU 72 acquires the input variables x (1) to x (51) of the map that outputs the imbalance rate Riv by the processing of S12. Substitute the value (S14). Specifically, the CPU 72 substitutes the minute rotation time T30 (m) for the input variable x (m) and substitutes the upstream mean value Afave (m) for the input variable (24 + m) with "m = 1 to 24". , The rotation speed NE is substituted into the input variable x (49), the filling efficiency η is substituted into the input variable x (50), and the 0.5th order amplitude Ampf / 2 is substituted into the input variable x (51).

The imbalance rate Riv is a value indicating the degree of variation between the actual air-fuel ratios when the fuel injection valve is operated to control the air-fuel ratios of the air-fuel mixture in each of the plurality of cylinders to be equal to each other. In the present embodiment, the imbalance rate Riv is set to "0" in the cylinder in which the fuel of the target injection amount is injected, and becomes a positive value when the actual injection amount is larger than the target injection amount. If it is small, it will be a negative value. That is, the CPU 72 determines that the farther the imbalance rate Riv is from "0", the greater the variation in the air-fuel ratio between the cylinders.

Next, the CPU 72 inputs the input variables x (1) to x (51) to the mapping defined by the mapping data 76a stored in the storage device 76 shown in FIG. 1, thereby causing the cylinder #i (i = 1 to 1). The imbalance rates Riv (1) to Riv (4) of 4) are calculated (S16). Then, the CPU 72 determines that the farther the calculated imbalance rate Riv is from "0", the greater the variation in the air-fuel ratio between the cylinders.

In this embodiment, this map is composed of a neural network having one intermediate layer. The above neural network is an input side that non-linearly transforms each of the input side coefficient wFjk (j = 0 to n, k = 0 to 51) and the output of the input side linear map which is a linear map defined by the input side coefficient wFjk. It includes an activation function h (x) as a non-linear map. In this embodiment, the hyperbolic tangent "tanh (x)" is exemplified as the activation function h (x). Further, the neural network non-linearly transforms each of the output side coefficient wSij (i = 1 to 4, j = 0 to n) and the output of the output side linear map which is a linear map defined by the output side coefficient wSij. It includes an activation function f (x) as an output-side non-linear map. In this embodiment, the hyperbolic tangent "tanh (x)" is exemplified as the activation function f (x). The value n indicates the dimension of the intermediate layer.

The CPU 72 temporarily ends the series of processes shown in FIG. 2 when the process of S16 is completed or when a negative determination is made in the process of S10.
Here, when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth (S13: NO), the CPU 72 determines whether or not the execution flag FE is ON (S17). As will be described later, the execution flag FE can be switched between ON and OFF each time the CPU 72 calculates the imbalance rate Riv (i) according to the mapping defined by the mapping data 76a. That is, when determining the execution flag FE, the execution flag FE is ON once out of two times, and the execution flag FE is OFF once out of two times.

Then, when the execution flag FE is in the ON state (S17: YES), the CPU 72 then switches the execution flag FE from the ON state to the OFF state (S18). Next, the processes of S14 and S16 described above are performed.

On the other hand, when the execution flag FE is in the OFF state (S17: NO) during the processing of S17, the CPU 72 switches the execution flag FE from the OFF state to the ON state (S19). Then, when the process of S19 is completed, the CPU 72 temporarily ends the series of processes shown in FIG.

FIG. 3 shows a procedure of processing using the imbalance rate Rivi (i). The process shown in FIG. 4 is realized by repeatedly executing the coping program 74b stored in the ROM 74 shown in FIG. 1 each time the CPU 72 repeatedly executes, for example, the imbalance rate Riv (i).

In the series of processes shown in FIG. 3, the CPU 72 first obtains the imbalance learning value Live (i) by the exponential moving average process in which the imbalance rate Riv (i) newly calculated by the process of FIG. 2 is input. Update (S20). That is, the CPU 72 has, for example, a value obtained by multiplying the imbalance learning value Live (i) stored in the storage device 76 by a coefficient α and a value obtained by multiplying the imbalance rate Riv (i) by “1-α”. The imbalance learning value Live is updated by the sum (S20). In addition, "0 <α <1".

Next, the CPU 72 determines whether or not the imbalance learning value Live (i) is equal to or greater than the lean side allowable limit value LL and equal to or less than the rich side allowable limit value LH (S22). When the CPU 72 determines that the imbalance learning value Live (i) is less than the lean side allowable limit value LL or is larger than the rich side allowable limit value (S22: NO), the CPU 72 repairs the user. The warning light 90 shown in FIG. 1 is operated to execute the notification process (S24).

On the other hand, when the CPU 72 determines that the lean side allowable limit value LL or more and the rich side allowable limit value LH or less (S22: YES), or when the processing of S24 is completed, the request of each cylinder is required. The injection amount Qd (#i) is corrected (S26). That is, the CPU 72 adds the required injection amount Qd (# i) of each cylinder to the correction amount ΔQd (Live (i)) corresponding to the imbalance learning value Live (i), thereby causing the required injection amount Qd (# i). ) Is corrected. Here, the correction amount ΔQd (Liv (i)) becomes a negative value when the imbalance learning value Liv (i) is larger than zero, and becomes a positive value when it is smaller than zero. When the imbalance learning value Liv (i) is zero, the correction amount ΔQd (Liv (i)) is also zero.

When the CPU 72 completes the process of S26, the CPU 72 temporarily ends the series of processes shown in FIG. Incidentally, in the present embodiment, when an affirmative determination is made in the process of S10 and the process of S12 is executed, the process of S26 is temporarily stopped.

Next, a method for generating mapping data 76a will be described.
FIG. 4 shows a system for generating mapping data 76a.
As shown in FIG. 4, in the present embodiment, the dynamometer 100 is mechanically connected to the crankshaft 24 of the internal combustion engine 10 via the torque converter 60 and the transmission 64. Then, various state variables when the internal combustion engine 10 is operated are detected by the sensor group 102, and the detection results are input to the matching device 104, which is a computer that generates mapping data 76a. The sensor group 102 includes a crank angle sensor 80, which is a sensor for detecting a value for generating an input to a map, an air flow meter 82, and an air-fuel ratio sensor 83.

FIG. 5 shows a procedure for generating mapping data. The process shown in FIG. 5 is performed by the matching device 104. The process shown in FIG. 5 may be realized, for example, by equipping the conforming device 104 with a CPU and a ROM and executing the program stored in the ROM by the CPU.

In the series of processes shown in FIG. 5, the matching device 104 first acquires the same data as the training data acquired in the process of S12 based on the detection result of the sensor group 102 (S30). In this process, a plurality of fuel injection valves 20 having various values different from zero in the imbalance rate Riv and three fuel injection valves having an imbalance rate of zero are measured in advance by a single unit. This is performed with three fuel injection valves 20 having a zero imbalance rate and one fuel injection valve 20 having a different imbalance rate different from zero mounted on the internal combustion engine 10. The imbalance rate Rivt of each of the mounted fuel injection valves is the teacher data.

Next, the matching device 104 substitutes training data other than the teacher data into the input variables x (1) to x (51) in the same manner as in S14 (S32). Then, the matching device 104 calculates the imbalance rates Riv (1) to Riv (4) using the input variables x (1) to x (51) obtained by the processing of S32 in the same manner as the processing of S16 (S34). ). Then, the CPU 72 determines whether or not the number of samples of the imbalance rate Rivi (i) calculated by the process of S34 is equal to or greater than a predetermined number (S36). Here, in order to be equal to or higher than a predetermined value, the operating state of the internal combustion engine 10 is changed with each of a plurality of fuel injection valves having an imbalance rate Rivt different from zero mounted on each of the cylinders # 1 to # 4. It is required that the imbalance rate Riv is calculated at various operating points defined by the rotation speed NE and the filling efficiency η.

When the conforming device 104 determines that the value is not equal to or higher than the predetermined value (S36: NO), the conforming device 104 returns to the process of S30. On the other hand, when the CPU 72 determines that the value is equal to or higher than a predetermined value (S36: YES), the difference between the imbalance coefficient Riv as teacher data and the imbalance coefficient Riv (i) calculated by the processing of S34 is different. The input-side coefficient wFjk and the output-side coefficient wSij are updated so as to minimize the sum of squares (S38). Then, the matching device 104 stores the updated input-side coefficient wFjk, output-side coefficient wSij, and the like as learned mapping data (S40).

Here, the operation and effect of this embodiment will be described.
(1) In the above embodiment, when the rotation speed NE of the crankshaft 24 is equal to or higher than the predetermined rotation speed NEth, the execution flag is ON for the calculation of the imbalance rate Riv (i) by the mapping data 76a. This is done in the case (S17: YES). On the other hand, the calculation of the imbalance rate Rivi (i) based on the mapping data 76a is not performed when the execution flag is in the OFF state (S17: NO). That is, when the rotation speed NE becomes equal to or higher than the predetermined rotation speed NEth, a part of the determination process for each degree of rotation by a specified angle is omitted. Therefore, when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth, the frequency at which the imbalance rate Riv (i) is calculated by the mapping data 76a is lower than when the rotation speed NE is less than the predetermined rotation speed NEth. Therefore, even if the rotation speed NE increases, the processing frequency does not become excessively high, and it is possible to prevent the processing load of the CPU 72 from becoming excessively large.

(2) In the above embodiment, the rotation speed NE and the filling efficiency η as operating point variables that define the operating point of the internal combustion engine 10 are input to the mapping. The amount of operation of the operation unit of the internal combustion engine 10 such as the ignition device 22, the EGR valve 34, and the intake side valve timing variable device 40 tends to be determined based on the operating point of the internal combustion engine 10. Therefore, the operating point variable is a variable that includes information on the amount of operation of each operation unit. Therefore, by using the operating point variable as the input of the map, the imbalance rate Riv (i) can be calculated based on the information on the manipulated variable of each operation unit, and the imbalance rate Riv (i) can be made more accurate. Can be calculated.

(3) In the above embodiment, the upstream average value Afave is included in the mapping input. As a result, compared with the case of using the upstream detection value Afu for each time interval of the time series data, the oxygen and unburned fuel flowing into the three-way catalyst 30 without increasing the number of data of the time series data can be obtained. Accurate information can be obtained, and the imbalance rate Riv (i) can be calculated with higher accuracy.

(4) By including the 0.5th-order amplitude Ampf / 2 in the input to the map, the imbalance rate Riv can be calculated with higher accuracy. That is, as shown in FIG. 6A, a linear relationship is established between the imbalance rate Riv and the 0.5th-order amplitude Ampf / 2. Further, as shown in FIG. 6B as an example of the case where the imbalance rate Riv (1) is "1.15", the amplitude of the rotation frequency of the crankshaft 24 is such that the cylinder whose imbalance rate Riv is not zero is used. If present, the 0.5th order component is particularly large. It is considered that this is because when the imbalance rate Rivi (i) is different from zero in any one of the cylinders # 1 to # 4, the generated torque deviates once in one combustion cycle. In the present embodiment, the imbalance rate Riv can be calculated with higher accuracy by incorporating the torque fluctuation of the 720 ° CA cycle as the 0.5th order amplitude Ampf / 2.

<Second embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment.

In the present embodiment, the imbalance rate Rivi (i) is calculated outside the vehicle.
FIG. 7 shows an imbalance detection system according to this embodiment. In FIG. 7, the members corresponding to the members shown in FIG. 1 are designated by the same reference numerals for convenience.

The control device 70 in the vehicle VC shown in FIG. 7 includes a communication device 79. The communication device 79 is a device for communicating with the center 120 via the network 110 outside the vehicle VC.
The center 120 analyzes the data transmitted from the plurality of vehicle VCs. The center 120 includes a CPU 122, a ROM 124, a storage device 126, peripheral circuits 127, and a communication device 129, which can be communicated by the local network 128. The imbalance detection main program 124a is stored in the ROM 124, and the mapping data 126a is stored in the storage device 126.

FIG. 8 shows a procedure of processing executed by the system shown in FIG. 7. The process shown in FIG. 8A is realized by the CPU 72 executing the imbalance detection subprogram 74c stored in the ROM 74 shown in FIG. 7. Further, the process shown in FIG. 8B is realized by the CPU 122 executing the imbalance detection main program 124a stored in the ROM 124. Note that the processes corresponding to the processes shown in FIG. 2 in FIG. 8 are assigned the same step numbers for convenience. Hereinafter, the processing shown in FIG. 8 will be described along with the time series of the imbalance detection processing.

As shown in FIG. 8A, when the CPU 72 completes the process of S12 in the vehicle VC, the CPU 72 determines whether or not the rotation speed NE is less than a predetermined predetermined rotation speed NEth (S13). .. Then, when the rotation speed NE is less than the predetermined rotation speed NEth (S13: YES), the CPU 72 acquires the input variables x (1) to x (51) of the map that outputs the imbalance rate Riv by the processing of S12. Substitute the value (S14). By operating the communication device 79, the data acquired in the process of S12a is transmitted to the center 120 together with the vehicle ID which is the identification information of the vehicle VC (S132).

On the other hand, as shown in FIG. 8B, the CPU 122 of the center 120 receives the transmitted data (S140) and executes the processes of S14 and S16. Then, by operating the communication device 129, the CPU 122 transmits a signal regarding the imbalance rate Rivi (i) to the vehicle VC to which the data received by the processing of S140 is transmitted (S142), and is shown in FIG. 8 (b). The series of processing is temporarily terminated. On the other hand, as shown in FIG. 8A, the CPU 72 receives the signal relating to the imbalance rate Rivi (i) (S134), and temporarily ends the series of processes shown in FIG. 8A.

Here, when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth (S13: NO), the CPU 72 determines whether or not the execution flag FE is ON (S17). When the execution flag FE is in the ON state (S17: YES), the CPU 72 then switches the execution flag FE from the ON state to the OFF state (S18). Next, the above-mentioned processing of S132 is performed.

On the other hand, when the execution flag FE is in the OFF state (S17: NO) during the processing of S17, the CPU 72 switches the execution flag FE from the OFF state to the ON state (S19). Then, when the process of S19 is completed, the CPU 72 temporarily ends the series of processes shown in FIG. 8 (a).

Here, the operation and effect of this embodiment will be described. In this embodiment, in addition to the above-mentioned effects (1) to (4), the following effects are exhibited.
(5) In the above embodiment, the calculation load of the control device 70 can be reduced by executing the imbalance determination process at the center 120.

<Third embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment described above.

The state determination device for the internal combustion engine of the first embodiment described above changes the state in which the air-fuel ratio imbalance between cylinders occurs in the internal combustion engine 10 to the rotational fluctuation of the crankshaft 24. It was configured as a device to judge based on. Even if a misfire occurs in the internal combustion engine 10, the combustion state varies between cylinders and the rotation fluctuation of the crankshaft 24 becomes large. The state determination device for the internal combustion engine of the present embodiment is configured as a device for determining a misfire that occurs in the internal combustion engine 10. The ROM 74 of the state determination device for the internal combustion engine of the present embodiment stores a misfire detection program instead of the imbalance detection program 74a shown in FIG.

In the series of processes shown in FIG. 9, the CPU 72 first acquires the minute rotation times T30 (1), T30 (2), ... T30 (24) (S210). The minute rotation time T30 is calculated by the CPU 72 measuring the time required for the crankshaft 24 to rotate 30 ° CA based on the crank signal Scr of the crank angle sensor 80. Here, when the numbers in parentheses are different, such as the minute rotation times T30 (1) and T30 (2), it indicates that they have different rotation angle intervals within 720 ° CA, which is one combustion cycle. That is, the minute rotation times T30 (1) to T30 (24) indicate the rotation times at each angle interval obtained by equally dividing the rotation angle region of 720 ° CA by 30 ° CA.

Next, the CPU 72 acquires the rotation speed NE and the filling efficiency η (S212). The rotation speed NE is calculated by the CPU 72 based on the crank signal Scr of the crank angle sensor 80, and the filling efficiency η is calculated by the CPU 72 based on the rotation speed NE and the intake air amount Ga.

Next, the CPU 72 determines whether or not the rotation speed NE is less than a predetermined predetermined rotation speed NEth (S213). Here, the predetermined rotation speed NEth is set as a value in which the load of the calculation process by the mapping data 76a, which will be described later, is correspondingly large with respect to the processing capacity of the CPU 72. Then, when the rotation speed NE is less than the predetermined rotation speed NEth (S213: YES), the CPU 72 sets S210, in the mapping input variables x (1) to x (26) for calculating the probability of misfire. The value acquired by the process of S212 is substituted (S214). Specifically, the CPU 72 substitutes the minute rotation time T30 (s) into the input variable x (s) with “s = 1 to 24”. That is, the input variables x (1) to x (24) are time series data of the minute rotation time T30. Further, the CPU 72 substitutes the rotation speed NE into the input variable x (25) and substitutes the filling efficiency η into the input variable x (26).

Next, the CPU 72 inputs the input variables x (1) to x (26) to the mapping defined by the mapping data 76a stored in the storage device 76 shown in FIG. 1, thereby causing the cylinder #i (i = 1 to 1). The probability P (i) that a misfire occurred in 4) is calculated (S216). The mapping data 76a defines a mapping capable of outputting the probability P (i) that a misfire has occurred in the cylinder #i during the period corresponding to the minute rotation times T30 (1) to T30 (24) acquired by the processing of S210. It is data. Here, the probability P (i) is a quantification of the degree of plausibility that a misfire actually occurred based on the input variables x (1) to x (26). However, in the present embodiment, the maximum value of the probability P (i) that a misfire has occurred in the cylinder #i is smaller than "1", and the minimum value is larger than "0". That is, in the present embodiment, the probability P (i) quantifies the degree of plausibility that a misfire actually occurred as a continuous value in a predetermined region larger than "0" and smaller than "1". It was done.

In the present embodiment, this mapping sets the sum of the probabilities P (1) to P (4) of misfire to be "1" by normalizing the output of the neural network having one intermediate layer and the output of the neural network. It is composed of a softmax function for. The above neural network is an input side that non-linearly transforms each of the input side coefficient wFjk (j = 0 to n, k = 0 to 26) and the output of the input side linear map which is a linear map defined by the input side coefficient wFjk. It includes an activation function h (x) as a non-linear map. In this embodiment, the hyperbolic tangent "tanh (x)" is exemplified as the activation function h (x). Further, the neural network non-linearly transforms each of the output side coefficient wSij (i = 1 to 4, j = 0 to n) and the output of the output side linear map which is a linear map defined by the output side coefficient wSij. It includes an activation function f (x) as an output-side non-linear map. In this embodiment, the hyperbolic tangent "tanh (x)" is exemplified as the activation function f (x). The value n indicates the dimension of the intermediate layer. In this embodiment, the value n is smaller than the dimension of the input variable x (here, 26 dimensions). Further, the input side coefficient wFj0 is a bias parameter, and is a coefficient of the input variable x (0) by defining the input variable x (0) as “1”. Further, the output side coefficient wSi0 is a bias parameter, and it is assumed that "1" is multiplied by this. This can be achieved, for example, by defining "wF00 · x (0) + wF01 · x (1) + ..." as an identity of infinity.

Specifically, the CPU 72 calculates the probability prototype y (i) which is the output of the neural network defined by the input side coefficient wFjk, the output side coefficient wSij, and the activation functions h (x) and f (x). The probability prototype y (i) is a parameter that has a positive correlation with the probability that a misfire has occurred in cylinder #i. Then, the CPU 72 calculates the probability P (i) that a misfire has occurred in the cylinder #i by the output of the softmax function that inputs the probability prototypes y (1) to y (4).

Next, the CPU 72 determines whether or not the maximum value P (m) of the probabilities P (1) to P (4) in which a misfire has occurred is equal to or greater than the threshold value Pth (S218). Here, the variable m takes any value of 1 to 4, and the threshold value Pth is set to a value of "1/2" or more. Then, when the CPU 72 determines that the threshold value is Pth or more (S218: YES), the CPU 72 increments the number of misfires N (m) of the cylinder #m having the maximum probability (S220). Then, the CPU 72 determines whether or not the number of times N (1) to N (4) is equal to or greater than the predetermined number of times Nth (S222). Then, when the CPU 72 determines that there is something that is Nth or more a predetermined number of times (S222: YES), misfires with a frequency exceeding the permissible range occur in a specific cylinder #q (q is one of 1 to 4). Assuming that it has occurred, "1" is substituted for the fail flag F (S224). At this time, the CPU 72 stores the information of the cylinder # q in which the misfire has occurred in the storage device 76, and retains the information at least until the misfire is resolved in the cylinder # q.

On the other hand, when the CPU 72 determines that the maximum value P (m) is less than the threshold value Pth (S218: NO), whether or not a predetermined period has elapsed since the processing of S224 or the processing of S228 described later is performed. Is determined (S226). Here, the predetermined period is longer than the period of one combustion cycle, and preferably has a length of 10 times or more of one combustion cycle.

When it is determined that the predetermined period has elapsed (S226: YES), the CPU 72 initializes the number of times N (1) to N (4) and initializes the fail flag F (S228).
The CPU 72 temporarily ends a series of processes shown in FIG. 9 when the processes of S224 and S228 are completed or when a negative determination is made in the processes of S222 and S226.

By the way, when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth (S213: NO), the CPU 72 determines whether or not the execution flag FE is ON (S230). When the execution flag FE is in the ON state (S230: YES), the CPU 72 then switches the execution flag FE from the ON state to the OFF state (S231). Next, the above-mentioned processing of S214 is performed.

On the other hand, when the execution flag FE is in the OFF state (S230: NO) during the processing of S230, the CPU 72 switches the execution flag FE from the OFF state to the ON state (S232). Then, when the process of S232 is completed, the CPU 72 performs the process of S218 described above. That is, when the processing of S232 is completed, the processing of S214 and S216 is not performed.

FIG. 10 shows a procedure for dealing with a misfire when it occurs. The process shown in FIG. 10 is realized by the CPU 72 executing the coping program 74b stored in the ROM 74 shown in FIG. 1 triggered by switching the fail flag F from “0” to “1”.

In the series of processes shown in FIG. 10, the CPU 72 first outputs an operation signal MS5 to the intake side valve timing variable device 40 so that the valve opening timing DIN of the intake valve 16 is set to the advance side, and the intake side valve timing variable device. Operate 40 (S250). Specifically, for example, in the normal time when the fail flag F is "0", the valve opening timing DIN is variably set according to the operating point of the internal combustion engine 10, and in the processing of S250, the valve opening timing DIN in the normal time is set. On the other hand, the actual valve opening timing DIN is advanced. The treatment of S250 aims to stabilize combustion by increasing the compression ratio.

Next, the CPU 72 determines whether or not the fail flag F is "1" after the processing of S250 is continued for a time equal to or longer than the predetermined period (S252). This process determines whether or not the situation in which a misfire occurs is resolved by the process of S250. When the CPU 72 determines that the fail flag F is "1" (S252: YES), the CPU 72 outputs an operation signal MS3 to the ignition device 22 to operate the ignition device 22 for the cylinder # q in which a misfire has occurred. The ignition timing aig is advanced by a predetermined amount Δ (S254). This process aims to eliminate the situation where a misfire occurs.

Next, the CPU 72 determines whether or not the fail flag F is "1" after the processing of S254 is continued for a time equal to or longer than the predetermined period (S256). This process determines whether or not the situation in which a misfire occurs is resolved by the process of S254. When the CPU 72 determines that the fail flag F is "1" (S256: YES), the CPU 72 outputs an operation signal MS2 to the fuel injection valve 20 to operate the fuel injection valve 20 for the cylinder # q in which a misfire has occurred. Then, the fuel injection valve 20 increases the required injection amount Qd, which is the amount of fuel required in one combustion cycle, by a predetermined amount (S258). This process aims to eliminate the situation where a misfire occurs.

Next, the CPU 72 determines whether or not the fail flag F is "1" after the processing of S258 is continued for a time equal to or longer than the predetermined period (S260). This process determines whether or not the situation in which a misfire occurs is resolved by the process of S258. When the CPU 72 determines that the fail flag F is "1" (S260: YES), the CPU 72 stops fuel injection for the misfire cylinder # q and limits the opening degree θ of the throttle valve 14 to the smaller side. While operating the throttle valve 14, the operation signal MS1 output to the throttle valve 14 is adjusted (S262). Then, the CPU 72 executes a process of notifying that a misfire has occurred by operating the warning light 90 shown in FIG. 1 that functions as a notification unit (S264).

The CPU 72 temporarily terminates the series of processes shown in FIG. 10 when a negative determination is made in the processes of S252, S256, and S260, that is, when the situation where a misfire occurs is resolved or when the process of S264 is completed. .. If an affirmative decision is made in the process of S262, the process of S264 is continued as a fail-safe process.

Incidentally, the mapping data 76a in the present embodiment is generated as follows, for example.
First, the internal combustion engine 10 to which the torque converter 60 is connected is installed on the test bench with the dynamometer connected to the output shaft of the torque converter 60. Then, the internal combustion engine 10 is operated on the test bench, and the fuel injection is stopped at a randomly selected timing among the timings for injecting the fuel required in each of the cylinders # 1 to # 4. Then, in the cylinder in which the fuel injection is stopped, the data in which the value of the combustion state variable PR is "1" is used as the teacher data, and in the cylinder in which the fuel injection is not stopped, the value of the combustion state variable PR is set to "0". Is included in the teacher data.

Then, the value of the combustion state variable PR is calculated by the same processing as the processing of S212 and S214 using the rotation waveform variable and the value of the variable acquired by the processing of S210 each time. The values of the input side coefficient wFjk and the output side coefficient wSij are learned so as to reduce the difference between the value of the combustion state variable PR calculated in this way and the teacher data. Specifically, for example, the values of the input side coefficient wFjk and the output side coefficient wSij may be learned so as to minimize the tolerance entropy. The input shaft rotation speed NT can be simulated by the rotation speed of the dynamometer.

Here, the operation and effect of this embodiment will be described.
(6) In the above embodiment, when the rotational speed NE of the crankshaft 24 becomes equal to or higher than a predetermined threshold value, the probability P of misfire occurs in the cylinder #i (i = 1 to 4) based on the mapping data 76a. The calculation of (i) is performed when the execution flag is in the ON state (S17: YES). On the other hand, the calculation of the probability P (i) that a misfire has occurred in the cylinder #i (i = 1 to 4) based on the mapping data 76a is not performed when the execution flag is in the OFF state (S17: NO). That is, when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth, the rotation speed NE determines the frequency at which the probability P (i) that a misfire has occurred in the cylinder #i (i = 1 to 4) based on the mapping data 76a is calculated. It is smaller than the case where the predetermined rotation speed is less than NEth. Therefore, even if the rotation speed NE is increased, the processing frequency is not excessively increased, and it is possible to prevent the processing load of the CPU 72 from being excessively increased.

<Correspondence>
The correspondence between the matters in the above-described embodiment and the matters described in the above-mentioned "means for solving the problem" column is as follows. In the following, the correspondence is shown for each number of the solution means described in the column of "Means for solving the problem". [1] The state determination device corresponds to the control device 70. The executing device corresponds to the CPU 72 and ROM 74 in the first and third embodiments, and corresponds to the CPU 72, 122 and ROM 74, 124 in the second embodiment. The storage device corresponds to the storage device 76 in the first and third embodiments and the storage device 126 in the second embodiment. The acquisition process corresponds to the process of S12 in the first and second embodiments and the process of S210 in the third embodiment. In the first and second embodiments, the internal combustion engine state variables have minute rotation times T30 (1), T30 (2), ... T30 (24) and upstream average values Afave (1), Afave (2), ... , Afave (24), and in the third embodiment, it corresponds to the minute rotation times T30 (1), T30 (2), ... T30 (24). The determination process corresponds to the processes of S13 to S16 of FIG. 2 and the processes of S213 to S216 of FIG. The specified angle corresponds to 720 ° CA. The threshold value corresponds to the predetermined rotation speed NEth. [2] The instantaneous velocity variable corresponds to the minute rotation time T30, and the plurality of rotation waveform variables correspond to the minute rotation times T30 (1), T30 (2), ... T30 (24). The air-fuel ratio detection variable corresponds to the upstream average values Afave (1), Afave (2), ..., Afave (24). The imbalance variable corresponds to the imbalance rate Riv. The first interval corresponds to 30 ° CA and the second interval corresponds to 30 ° CA. The coping process corresponds to the process of FIG. The predetermined hardware corresponds to the warning light 90 and the fuel injection valve 20. [3] The third interval corresponds to 720 ° CA, the fourth interval corresponds to 30 ° CA, and the instantaneous speed parameter corresponds to the minute rotation time T30. The determination process corresponds to the processes of S214 to S216. The coping process corresponds to the process of FIG. The predetermined hardware corresponds to the intake side valve timing variable device 40, the ignition device 22, the fuel injection valve 20, and the throttle valve 14. [4] The first execution device corresponds to the CPU 72 and the ROM 74. The second execution device corresponds to the CPU 122 and the ROM 124. The vehicle-side transmission process corresponds to the process of S132 in FIG. The external reception process corresponds to the process of S140 in FIG. The "signal based on the output calculated by the output calculation process" corresponds to the signal related to the determination result. [5] The data analysis device corresponds to the center 120. [6] The control device for the internal combustion engine corresponds to the control device 70 shown in FIG. 7.

(Other embodiments)
In addition, this embodiment can be implemented by changing as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

・ "About internal combustion engine state variables"
In the above embodiment, the internal combustion engine state variable input to the map is not limited to the example of the above embodiment. As the rotation waveform variable in the first and second embodiments, the minute rotation time T30 at each of the plurality of intervals in which the rotation angle interval of 720 ° CA, which is one combustion cycle, is divided is used as an input to the map. Not limited to this. For example, of 0 to 720 ° CA, 0 to 20, 40 to 60, 80 to 100, 120 to 140, 160 to 180, ..., 700 to 720 are set as the second intervals, and the time required for their rotation is set. May be used as an input to the map. Further, the instantaneous speed parameter in the third embodiment is not limited to the minute rotation time, which is the time required for the rotation at the fourth interval. For example, it may be a value obtained by dividing the fourth interval by a minute rotation time. It is not essential that the instantaneous velocity parameter is normalized so that the difference between the maximum value and the minimum value is a fixed value. Further, the filter processing as the preprocessing for inputting the map is not limited to the above-mentioned one, and the crankshaft 24 is rotated by the input shaft 66 based on, for example, the minute rotation time of the input shaft 66 of the transmission 64. It may be considered that the processing for removing the affected part has been performed. However, it is not essential that the instantaneous velocity parameter as the input of the map is filtered. Further, the internal combustion engine state variable is not particularly limited as long as it is a parameter indicating the state of the internal combustion engine.

・ "About partial omission of judgment processing"
In the above embodiment, while the acquisition process is performed every 720 ° CA, when the rotation speed NE is the predetermined rotation speed NEth, the determination process is not performed for each acquisition process, thereby partially omitting the determination process. However, the partial omission of the determination process is not limited to the example of the above embodiment. For example, in the first embodiment, a second specified angle different from the specified angle is set, and the CPU 72 performs acquisition processing for each second specified angle when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth. To do. At this time, the second specified angle may be set to be larger than the specified angle, for example, 1440 ° CA. In this case, the CPU 72 first compares the rotation speed NE with the predetermined rotation speed NEth before S12. Then, when the rotation speed NE is less than the predetermined rotation speed NEth, the CPU 72 executes the acquisition process of S12 every time the rotation speed NE is rotated by 720 ° CA, and determines the determination processes of S14 and S16 each time the acquisition process is performed. Do. On the other hand, when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth, the CPU 72 performs the processing of S12 to S16 for each 1440 ° CA of the second specified angle. In this case, the CPU 72 performs the determination process every 720 ° CA when the rotation speed NE is less than the predetermined rotation speed NEth, while the CPU 72 performs the determination process every 1440 ° CA when the rotation speed NE is equal to or more than the predetermined rotation speed NEth. Judgment processing is performed. When the rotation speed NE is equal to or higher than the predetermined rotation speed NEth, once every two times is omitted from the determination process of 720 ° CA rotation when the rotation speed NE is less than the predetermined rotation speed NEth. As a result, the frequency of the determination process is lower when the rotation speed NE is equal to or higher than the predetermined rotation speed NEth than when the rotation speed NE is less than the predetermined rotation speed NEth. Therefore, it is possible to reduce the frequency of the determination process by reducing the frequency of the acquisition process of the determination process.

・ "Frequency of omitting judgment processing"
In the above embodiment, the execution flag is switched each time the acquisition process is performed. Therefore, the CPU 72 omits the determination process twice, that is, once every two combustion cycles, but the determination process is performed. The frequency of omission is not limited to the example of the above embodiment. For example, it may be omitted at a frequency of once in three combustion cycles, or it may be omitted at a frequency of three times in four combustion cycles. Further, the frequency of the determination process may be changed depending on the rotation speed NE of the crankshaft 24. Specifically, the number of times the determination process is omitted is counted by the counter before the process of S18 or S19, and when the predetermined number of times is reached, the determination process of S18 or S19 may be performed.

・ "About the 1st interval and the 2nd interval"
In the first and second embodiments, the first interval, which is the sampling interval of the upstream average value Afave that is the input to the map, is not limited to 30 ° CA. The angle interval may be smaller than 30 ° CA, for example, 10 ° CA. However, the interval is not limited to 30 ° CA or less, and may be, for example, 45 ° CA.

The second interval, which is the sampling interval of the minute rotation time T30 that is the input to the map, is not limited to 30 ° CA. The angle interval may be smaller than 30 ° CA, for example, 10 ° CA. However, the interval is not limited to 30 ° CA or less, and may be, for example, 45 ° CA. It is not essential that the third interval and the fourth interval have the same size.

・ "About the 3rd and 4th intervals"
In the third embodiment, the minute rotation time T30 as an instantaneous velocity parameter in each of a plurality of continuous second intervals within the rotation angle interval of 720 ° CA, which is one combustion cycle, is mapped for determining the presence or absence of misfire. It was used as the input parameter of. That is, an example is shown in which the third interval is 720 ° CA and the fourth interval is 30 ° CA, but the present invention is not limited to this. For example, the first interval may be a rotation angle interval longer than 720 ° CA. However, it is not essential that the third interval is 720 ° CA or more. For example, the input such as a mapping for outputting data on the probability of misfire or the generated torque in a specific cylinder may be an interval of 720 ° CA or less, such as setting the third interval to 480 ° CA. At this time, it is desirable that the rotation angle interval is longer than the appearance interval of the compression top dead center. The third interval includes the compression top dead center of the cylinder for which the probability of misfire is determined.

The fourth interval is not limited to 30 ° CA. The angle interval may be smaller than 30 ° CA, for example, 10 ° CA. However, the interval is not limited to 30 ° CA or less, and may be, for example, 45 ° CA.

・ "Parameters that specify the operating point of the internal combustion engine"
In the third embodiment, the operating point is defined by the rotation speed NE and the filling efficiency η, but the present invention is not limited to this. For example, the rotation speed NE and the intake air amount Ga may be used. Further, for example, as the load, the injection amount or the required torque for the internal combustion engine may be used instead of the filling efficiency η. Using the injection amount and the required torque as the load is particularly effective in the compression ignition type internal combustion engine described in the column of "About the internal combustion engine" below.

・ "About map input"
In the third embodiment, the input of the map to be input in addition to the instantaneous speed parameter is not limited to the example of the above embodiment. For example, a parameter for adjusting the combustion speed of the air-fuel mixture in the combustion chamber 18 of the internal combustion engine 10 and a state variable of the road surface on which the vehicle VC on which the internal combustion engine 10 is mounted may be included. Further, it is not essential to include the operating point of the internal combustion engine 10 in the input of the map. For example, if the internal combustion engine is installed in a series hybrid vehicle and the operating point is limited to a narrow range as described in the "About internal combustion engine" column below, the operating point is set. It does not have to be included. Further, only one of the two parameters of the rotation speed NE and the load that defines the operating point, or the rotation speed NE and the intake air amount may be input in addition to the instantaneous speed parameter.

Similarly, in the first and second embodiments, the input of the mapping to be input in addition to the rotation waveform variable and the plurality of air-fuel ratio detection variables is not limited to the example of the above embodiment. Further, it is not essential to include the operating point of the internal combustion engine 10 in the input of the map.

Further, for example, for some of the plurality of types of physical quantities input to the detection mapping in the above embodiment, instead of directly inputting to the neural network or regression equation, some mains are analyzed by their principal component analysis. The component may be a direct input to a neural network or regression equation. However, when the principal component is the input of the neural network or the regression equation, it is not essential that only a part of the input to the neural network or the regression equation is the principal component, and the whole may be the principal component. When the main component is input to the detection map, the mapping data 76a and 126a include data that defines the detection map that determines the main component.

・ "About the internal combustion engine status judgment system"
In the third embodiment, when performing the process related to the detection of misfire, the state determination system of the internal combustion engine may be configured as in the second embodiment. In this case, the center 120 may determine misfire and transmit the determination result to the vehicle VC.

・ "Corrective action"
The configuration of the coping process in the above embodiment is not limited to the example of the above embodiment. For example, by operating the warning light 90, it is notified through visual information that a misfire has occurred, but the present invention is not limited to this. For example, by operating the speaker, it may be notified that a misfire has occurred through auditory information. Further, for example, the control device 70 shown in FIG. 1 may be provided with the communication device 129, and the communication device 129 may be operated to transmit a signal to the user's mobile terminal that a misfire has occurred. This can be achieved by installing an application program that executes the notification process on the user's mobile terminal. Further, as the coping process in the first embodiment, a part or all of the process shown in FIG. 3 may be omitted. In this respect, the same applies to the process of FIG. 10 in the third embodiment.

・ "About mapping data"
In the above embodiment, the activation functions h, h1, h2, ... Hα are set as hyperbolic tangents, and the output activation function is set as a softmax function, but the present invention is not limited to this. For example, the activation functions h, h1, h2, ... Hα may be used as ReLU. Further, for example, the output activation function may be a logistic jigmoid function. In this case, for example, the number of nodes in the output layer may be one, and the output variable may be the combustion state variable PR. In that case, the presence or absence of an abnormality can be determined by determining an abnormality when the value of the output variable is equal to or greater than a predetermined value.

・ "About machine learning algorithms"
The machine learning algorithm is not limited to the one using a neural network. For example, a regression equation may be used. This corresponds to the above neural network that does not have an intermediate layer.

・ "About the method of generating mapping data"
In the third embodiment, learning is performed in a situation where misfires occur randomly, but the learning is not limited to this. For example, learning may be performed in a situation where misfires occur continuously in a specific cylinder. However, in that case, the inter-cylinder variable used as the input to the mapping and the inter-cylinder variable used for the fluctuation pattern variable are minute corresponding to the compression top dead center of the cylinder for which misfire is detected and the other cylinders. It is desirable that the rotation time is the difference between the T30s.

Further, in the above embodiment, the method of generating mapping data is not limited to the one in which learning is performed based on the rotational behavior of the crankshaft 24 when the dynamometer of the crankshaft 24 is connected and the internal combustion engine 10 is operated. For example, the internal combustion engine 10 may be mounted on a vehicle, and learning may be performed based on the rotational behavior of the crankshaft 24 when the vehicle is driven. According to this, the influence of the rotational behavior of the crankshaft 24 depending on the state of the road surface on which the vehicle travels can be reflected in the learning.

・ "About data analysis equipment"
In the second embodiment, the process of FIG. 8B may be executed by, for example, a mobile terminal owned by the user. This can be achieved by installing an application program that executes the process shown in FIG. 7 on the mobile terminal. At this time, the transmission / reception processing of the vehicle ID may be deleted, for example, by setting the effective distance for transmitting data in the processing of S132 to be about the length of the vehicle.

・ "About the execution device"
The execution device in each embodiment is not limited to the one provided with CPUs 72, 122 and ROMs 74, 124 to execute software processing. For example, a dedicated hardware circuit (for example, ASIC or the like) for hardware processing of at least a part of the software processed in the above embodiment may be provided. That is, the executing device may have any of the following configurations (a) to (c). (A) A processing device that executes all of the above processing according to a program and a program storage device such as a ROM that stores the program are provided. (B) A processing device and a program storage device that execute a part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing are provided. (C) A dedicated hardware circuit for executing all of the above processes is provided. Here, there may be a plurality of software execution devices including a processing device and a program storage device, and a plurality of dedicated hardware circuits.

・ "About storage device"
In the first and second embodiments, the storage device that stores the mapping data 76a and 126a and the ROM 74 and 124 that are the storage devices that store the imbalance detection program 74a and the imbalance detection main program 124a are separated. However, it is not limited to this. In this respect, the same applies to the storage device that stores the mapping data 76a and the misfire detection program in the third embodiment.

・ "About computers"
The computer is not limited to the one including the execution device such as the CPU 72 and the ROM 74 mounted on the vehicle and the execution device such as the CPU 122 and the ROM 124 included in the center 120. For example, it may be configured by an execution device mounted on a vehicle, an execution device included in the center 120, and an execution device such as a CPU and a ROM in the user's mobile terminal. This can be realized by, for example, the process of S132 in FIG. 8B being transmitted to the user's mobile terminal, and the processes of S140, S14 to S16, and S142 being executed on the mobile terminal.

・ "About the state of the internal combustion engine"
If the acquisition process is performed every time the crankshaft 24 rotates by a predetermined angle, the state of the internal combustion engine 10 determined by the determination process may be a state other than misfire or intercylinder air-fuel ratio imbalance. For example, even when the so-called decompression occurs in a specific cylinder, the compression of the intake air in the cylinder becomes insufficient due to the valve opening sticking of the intake valve and the exhaust valve, the combustion state between the cylinders varies. The rotation fluctuation of the crankshaft 24 becomes large. Therefore, if such compression loss is detected by using the mapping with the above-mentioned internal combustion engine state variable as an input, the compression loss can be determined in a form that reflects the influence on the rotational behavior of the crankshaft 24.

・ "About the combination of each embodiment"
Both the imbalance detection program 74a in the first and second embodiments and the misfire detection program in the third embodiment are installed, and the CPU 72 determines which of the misfire and the air-fuel ratio imbalance between cylinders. The state of may also be determined. In this case, the calculation load of the CPU 72 is larger than that of determining either the misfire or the air-fuel ratio imbalance between cylinders. Therefore, when the rotational speed NE of the crankshaft 24 is correspondingly large, each of the above embodiments is performed. It is very effective in applying.

Further, the imbalance detection program may be determined by the vehicle VC while the imbalance detection program may be determined by the center 120 by combining the first and second embodiments. Further, in combination with the second and third embodiments, the center 120 may determine the state of air-fuel ratio imbalance between cylinders, while the vehicle VC may determine the state of misfire.

・ "About the center"
In the second embodiment, the center 120 does not have to transmit the imbalance rate Riv to the vehicle VC. In this case, the imbalance rate Riv can be stored in the center 120 and utilized for research and development.

・ "About internal combustion engine"
In the above embodiment, as the fuel injection valve, an in-cylinder injection valve that injects fuel into the combustion chamber 18 has been exemplified, but the present invention is not limited to this. For example, it may be a port injection valve that injects fuel into the intake passage 12. Further, for example, both a port injection valve and an in-cylinder injection valve may be provided. The internal combustion engine is not limited to the spark ignition type internal combustion engine, and may be, for example, a compression ignition type internal combustion engine that uses light oil or the like as fuel.

・ "About the vehicle"
The vehicle VC of the above embodiment has a configuration in which the lockup clutch 62, the torque converter 60, and the transmission 64 are provided in the drive system, but vehicles having different drive system configurations may be used.

10 ... Internal combustion engine, 12 ... Intake passage, 14 ... Throttle valve, 16 ... Intake valve, 18 ... Combustion chamber, 20 ... Fuel injection valve, 22 ... Ignition device, 24 ... Crankshaft, 26 ... Exhaust valve, 28 ... Exhaust passage , 30 ... Three-way catalyst, 32 ... EGR passage, 34 ... EGR valve, 40 ... Intake side valve timing variable device, 42 ... Intake side cam shaft, 44 ... Exhaust side valve timing variable device, 46 ... Exhaust side cam shaft, 50 ... Crankrotor, 52 ... Tooth, 54 ... Missing tooth, 60 ... Torque converter, 62 ... Lockup clutch, 64 ... Transmission, 66 ... Input shaft, 68 ... Output shaft, 69 ... Drive wheel, 70 ... Control device , 72 ... CPU, 74 ... ROM, 74a ... imbalance detection program, 74b ... coping program, 74c ... misfire detection subprogram, 76 ... storage device, 76a ... mapping data, 77 ... peripheral circuit, 78 ... local network, 79 ... Communication device, 80 ... Crank angle sensor, 82 ... Air flow meter, 83 ... Air fuel ratio sensor, 84 ... Water temperature sensor, 86 ... Shift position sensor, 88 ... Acceleration sensor, 90 ... Warning light, 100 ... Dynamometer, 102 ... Sensor group , 104 ... Compatible device, 110 ... Network, 120 ... Center, 122 ... CPU, 124 ... ROM, 124a ... Main program for imbalance detection, 126 ... Storage device, 126a ... Mapping data, 127 ... Peripheral circuit, 128 ... Local network 129 ... Communication device.

Claims (6)

Equipped with a storage device and an execution device,
The storage device stores mapping data, which is data that defines a mapping that outputs a determination result of the state of the internal combustion engine by inputting an internal combustion engine state variable which is a parameter indicating the state of the internal combustion engine.
The execution device obtains the state of the internal combustion engine each time the crankshaft of the internal combustion engine rotates by a predetermined angle, and obtains the state of the internal combustion engine based on the output of the mapping with the state variable of the internal combustion engine as an input. Judgment Judgment processing is executed and
The mapping data is data that has been learned by machine learning, and is
The execution device is a state determination device for an internal combustion engine that omits a part of the determination process for each rotation at a predetermined angle when the rotation speed of the crankshaft becomes equal to or higher than a predetermined threshold value. The internal combustion engine is equipped with a plurality of cylinders.
The state of the internal combustion engine is a variation in the air-fuel ratio among a plurality of cylinders.
When the execution device determines that the air-fuel ratio varies between a plurality of cylinders by the determination process, the executing device executes a coping process for coping with a large degree of variation in the air-fuel ratio by operating predetermined hardware. And
The mapping data uses the rotation waveform variable and the air-fuel ratio detection variable, which is a variable corresponding to the output of the air-fuel ratio sensor at each of the plurality of first intervals, as inputs, and sets the air-fuel ratio of the air-fuel mixture in each of the plurality of cylinders to each other. It defines a mapping that outputs an imbalance variable, which is a variable that indicates the degree of variation between the actual air-fuel ratios when the fuel injection valve is operated to control to the same air-fuel ratio.
In the acquisition process, the execution device acquires the rotation waveform variable based on the detection value of the sensor that detects the rotational behavior of the crankshaft and the air-fuel ratio detection variable at each of the plurality of first intervals.
The rotation waveform variable is a variable indicating the difference between the instantaneous speed variables, which are variables corresponding to the rotation speed of the crankshaft at each of the plurality of second intervals.
The first interval and the second interval are both angular intervals of the crankshaft smaller than the appearance interval of the compression top dead center.
The state determination of the internal combustion engine according to claim 1, wherein the rotation waveform variable and the plurality of air-fuel ratio detection variables used as input of the map are time-series data within a predetermined angular interval larger than the appearance interval, respectively. apparatus. The state of the internal combustion engine is the presence or absence of misfire of the internal combustion engine.
When the executing device determines that a misfire has occurred due to the determination process, the executing device executes a coping process for coping with the misfire caused by operating predetermined hardware.
The mapping data specifies a mapping that outputs the probability that a misfire has occurred in the internal combustion engine by inputting time-series data which is an instantaneous speed parameter in each of a plurality of consecutive fourth intervals included in the third interval. Yes,
In the acquisition process, the execution device acquires the instantaneous speed parameter based on the detection value of the sensor that detects the rotational behavior of the crankshaft of the internal combustion engine.
The instantaneous speed parameter is a parameter corresponding to the rotational speed of the crankshaft of the internal combustion engine.
The third interval is the rotation angle interval of the crankshaft and is an interval including the compression top dead center.
The fourth interval is an interval smaller than the appearance interval of the compression top dead center.
The state determination device for an internal combustion engine according to claim 1, wherein the mapping outputs the probability that a misfire has occurred in at least one cylinder in which a compression top dead center appears within the third interval. The executing device and the storage device according to any one of claims 1 to 3 are provided.
The execution device includes a first execution device and a second execution device.
The first execution device is mounted on the vehicle and executes the acquisition process and the vehicle-side transmission process of transmitting the data acquired by the acquisition process to the outside of the vehicle.
The second execution device is a state determination system for an internal combustion engine that is arranged outside the vehicle and executes an external reception process for receiving data transmitted by the vehicle side transmission process and the determination process. .. A data analysis device including the second execution device and the storage device according to claim 4. A control device for an internal combustion engine including the first execution device according to claim 4.