Control system for hybrid vehicles

Abstract

The present invention provides a control device for hybrid vehicles that can suppress the deterioration of the accuracy of the process for diagnosing the presence or absence of filter defects. [Solution] The hybrid vehicle comprises an internal combustion engine, a control device, a filter for collecting particulate matter contained in the exhaust, and a differential pressure sensor for detecting differential pressure between the front and rear. The control device includes a processing circuit. When a predetermined first condition is met (step S20: YES), the processing circuit repeatedly performs a process to acquire differential pressure data between the front and rear (step S21). When a predetermined second condition is met (step S25: YES), the processing circuit performs active control to change the fuel injection amount in a target cylinder among the multiple cylinders of the internal combustion engine (step S26). The processing circuit does not perform the process of acquiring differential pressure data between the front and rear and the active control simultaneously.

Description

Technical Field

[0001] This invention relates to a control device for a hybrid vehicle.

Background Art

[0002] Patent Document 1 discloses a vehicle in which a collector for collecting fine particles in exhaust gas is installed in the middle of an exhaust passage. The collector incorporates a filter for collecting fine particles. The control device of the vehicle diagnoses the presence or absence of a filter defect by detecting, with a differential pressure sensor, the differential pressure (pressure difference between the upstream side and the downstream side of the collector) between the upstream side and the downstream side of the collector.

[0003] Patent Document 2 discloses a control device for diagnosing whether any one of a plurality of cylinders provided in an internal combustion engine is in a rich imbalance state. Rich imbalance refers to a state in which the air-fuel ratio is shifted to the rich side compared to other cylinders. This control device commands fuel injection in an amount such that the air-fuel ratio of the fuel injection valve of the target cylinder is set to an air-fuel ratio leaner than the stoichiometric air-fuel ratio, and at the same time commands fuel injection in an amount such that the air-fuel ratio of the variable injection valves of the cylinders other than the target cylinder is set to the stoichiometric air-fuel ratio, and executes lean active control. If there is no shift in the air-fuel ratio between the target cylinder and the cylinders other than the target cylinder before the start of the lean active control, the control device causes a shift in the air-fuel ratio between the plurality of cylinders by implementing the lean active control. When a shift in the air-fuel ratio occurs between the plurality of cylinders, the rotational fluctuation of the crankshaft increases. If the air-fuel ratio of the target cylinder is shifted to the rich side compared to the air-fuel ratio of the cylinders other than the target cylinder before the start of the lean active control, the control device reduces the shift in the air-fuel ratio between the target cylinder and the cylinders other than the target cylinder by implementing the lean active control. In this case, the rotational fluctuation of the crankshaft does not increase. The control device diagnoses the presence or absence of rich imbalance in the target cylinder based on the rotational fluctuation of the crankshaft while the lean active control is being implemented.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-247550 [Patent Document 2] Japanese Patent Publication No. 2017-115592 [Overview of the project] [Problems that the invention aims to solve]

[0005] When a control device diagnoses the presence or absence of a filter defect based on the differential pressure between cylinders, it is preferable that the exhaust gas flow rate through the exhaust passage is stable. When a control device performs active control to change the fuel injection amount in a target cylinder in order to diagnose the presence or absence of an air-fuel ratio imbalance between multiple cylinders, the fluctuation in the exhaust gas flow rate in the exhaust passage may increase with increasing fluctuations in crankshaft rotation. Therefore, when a control device performs the process of diagnosing an air-fuel ratio imbalance between multiple cylinders and the process of diagnosing the presence or absence of a filter defect based on the differential pressure between cylinders simultaneously, the accuracy of the process of diagnosing the presence or absence of a filter defect may deteriorate. [Means for solving the problem]

[0006] The control device for a hybrid vehicle to solve the above problems is applied to a hybrid vehicle that includes an internal combustion engine and a motor generator as power sources to drive the drive shaft, a battery that charges with electricity generated by the motor generator using the output of the internal combustion engine, an exhaust passage that guides exhaust from the internal combustion engine to the rear of the vehicle, a filter that collects particulate matter contained in the exhaust, and a differential pressure sensor that detects the front-to-rear differential pressure, which is the difference between the pressure upstream of the filter and the pressure downstream of the filter. The control device for the hybrid vehicle includes a processing circuit. The processing circuit repeatedly performs a process to acquire the front-to-rear differential pressure data when a predetermined first condition is met. When the processing circuit has acquired a predetermined first number of front-to-rear differential pressure data, it performs a first diagnosis, which is a process to diagnose whether or not there is a defect in the filter using the front-to-rear differential pressure data. When a predetermined second condition is met, the processing circuit performs active control to change the fuel injection amount in a target cylinder among a plurality of cylinders of the internal combustion engine. While the active control is being performed, the processing circuit repeatedly performs a process to acquire data on the rotational fluctuation of the crankshaft. When the processing circuit acquires a predetermined second number of rotational fluctuation data, it performs a second diagnosis, which is a process that diagnoses whether or not there is an air-fuel ratio imbalance between the multiple cylinders using the rotational fluctuation data. The processing circuit does not perform the process of acquiring the front-to-rear differential pressure data and the active control simultaneously. [Effects of the Invention]

[0007] The above-mentioned control device can accurately acquire differential pressure data, thereby suppressing the deterioration of the accuracy of the process for diagnosing whether or not there is a defect in the filter. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing the configuration of the control device in the first embodiment and the hybrid vehicle to which the control device is applied. [Figure 2]Figure 2 is a flowchart showing the sequence of processes in which the processing circuit shown in Figure 1 performs the first and second diagnoses. [Figure 3] Figure 3 is a flowchart showing the sequence of processes by which the processing circuit shown in Figure 1 determines whether or not to acquire differential pressure data and whether or not to perform active control. [Figure 4] Figure 4 is a flowchart showing the sequence of processes by which the processing circuit of the modified example of the first embodiment determines whether or not to acquire differential pressure data and whether or not to perform active control. [Figure 5] Figure 5 is a flowchart showing the sequence of processes by which the processing circuit of the second embodiment determines whether or not to acquire differential pressure data and whether or not to perform active control. [Figure 6] Figure 6 is a flowchart showing the continuation of the process shown in Figure 5. [Figure 7] Figure 7 is a flowchart showing the sequence of processes by which the processing circuit of the modified example of the second embodiment determines whether or not to acquire differential pressure data and whether or not to perform active control. [Figure 8] Figure 8 is a flowchart showing the continuation of the process shown in Figure 7. [Modes for carrying out the invention]

[0009] (First Embodiment) The first embodiment of the control device for a hybrid vehicle will be described below with reference to Figures 1 to 3.

[0010] <Configuration of hybrid vehicle 1 to which control device 100 is applied> As shown in Figure 1, the control device 100 of this embodiment includes a processing circuit 101 that executes a program and performs various processes, and a storage device 102 in which the program is stored. The processing circuit 101 includes a processor. The storage device 102 is capable of storing various data. The hybrid vehicle 1 to which the control device 100 is applied is equipped with an internal combustion engine 10. The hybrid vehicle 1 is equipped with a first motor generator 71 and a second motor generator 72, which are two motor generators that combine the functions of both a motor and a generator. The hybrid vehicle 1 is equipped with a battery 77, a first inverter 75 and a second inverter 76. The battery 77 charges the power generated by the first motor generator 71 and the second motor generator 72 using the output of the internal combustion engine 10. The battery 77 supplies the stored power to the first motor generator 71 and the second motor generator 72 when they are functioning as motors. The first inverter 75 adjusts the amount of power exchanged between the first motor generator 71 and the battery 77. The second inverter 76 adjusts the amount of power exchanged between the second motor generator 72 and the battery 77.

[0011] The internal combustion engine 10 has multiple cylinders 11 for burning a fuel-air mixture. The internal combustion engine 10 is provided with an intake passage 15 that serves as an introduction path for air to the multiple cylinders 11. The intake passage 15 is equipped with a throttle valve 16, which is a valve for adjusting the amount of intake air. The portion of the intake passage 15 downstream of the throttle valve 16 branches out for each cylinder. Each of the cylinder-specific branches in the intake passage 15 is equipped with a fuel injection valve 17. Each of the multiple cylinders 11 is equipped with an ignition device 18 that ignites the fuel-air mixture introduced into the cylinder 11 by spark discharge.

[0012] The hybrid vehicle 1 is provided with an exhaust passage 21 that guides the exhaust gas discharged from the cylinder 11 during operation of the internal combustion engine 10 to the rear of the vehicle. The exhaust passage 21 is equipped with a catalytic converter 22 that oxidizes HC and CO and reduces NOx in the exhaust gas. Downstream of the exhaust from the catalytic converter 22 is a filter 23 that collects particulate matter contained in the exhaust gas. Downstream of the exhaust from the catalytic converter 22 is a differential pressure sensor 83 that detects the differential pressure, which is the difference between the pressure upstream of the filter 23 and the pressure downstream of the filter 23. The differential pressure is a value relating to the exhaust pressure within the exhaust passage 21. The processing circuit 101 acquires the differential pressure detection signal from the differential pressure sensor 83.

[0013] The hybrid vehicle 1 is equipped with a first planetary gear mechanism 40. The first planetary gear mechanism 40 has an external gear sun gear 41 and an internal gear ring gear 42 which is coaxially arranged with the sun gear 41. Between the sun gear 41 and the ring gear 42 are a plurality of pinion gears 43 which mesh with both the sun gear 41 and the ring gear 42. Each pinion gear 43 is supported by a carrier 44 so as to be able to rotate and revolve freely. The carrier 44 of the first planetary gear mechanism 40 is connected to a crankshaft 14, which is the output shaft of the internal combustion engine 10. A first motor generator 71 is connected to the sun gear 41. A ring gear shaft 45 is connected to the ring gear 42. Drive wheels 63 are connected to the ring gear shaft 45 via a reduction mechanism 60, a differential mechanism 61, and a drive shaft 62. The internal combustion engine 10, the first motor generator 71, and the second motor generator 72 are power sources that drive the drive shaft 62. The second motor generator 72 is connected to the ring gear shaft 45 via the second planetary gear mechanism 50.

[0014] The second planetary gear mechanism 50 has a sun gear 51 of an external gear and a ring gear 52 of an internal gear arranged coaxially with the sun gear 51. Between the sun gear 51 and the ring gear 52, a plurality of pinion gears 53 that mesh with both the sun gear 51 and the ring gear 52 are arranged. Each pinion gear 53 is rotatable about its own axis but unable to revolve. A ring gear shaft 45 is connected to the ring gear 52. A second motor generator 72 is connected to the sun gear 51.

[0015] The processing circuit 101 acquires detection signals from various sensors installed in the internal combustion engine 10. In the internal combustion engine 10, an air flow meter 82, a crank angle sensor 85, and a water temperature sensor 86 are provided as sensors. The air flow meter 82 is provided in a portion of the intake passage 15 upstream of the throttle valve 16. The air flow meter 82 detects the intake air amount, which is the flow rate of air flowing through the intake passage 15 that introduces outside air into the internal combustion engine 10. The crank angle sensor 85 is provided near the crankshaft 14. The crank angle sensor 85 detects the rotational phase of the crankshaft 14. The processing circuit 101 calculates the engine rotational speed NE, which is the rotational speed of the crankshaft 14 of the internal combustion engine 10, based on the detection signal of the crank angle sensor 85. The water temperature sensor 86 detects the temperature of the cooling water flowing through the cooling water passage of the internal combustion engine 10.

[0016] The processing circuit 101 acquires a detection signal of the operation amount of the driver's accelerator pedal from the accelerator position sensor 80. The processing circuit 101 acquires a detection signal of the vehicle speed, which is the traveling speed of the hybrid vehicle 1, from the vehicle speed sensor 81. The processing circuit 101 acquires the SOC (State of Charge), which is the amount of electric power stored in the battery 77, from the battery 77.

[0017] The processing circuit 101 calculates a required torque, which is a required value of the torque output to the ring gear shaft 45, based on the operation amount of the accelerator pedal and the vehicle speed. The processing circuit 101 determines the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 according to the required torque and the SOC of the battery 77. The processing circuit 101 controls the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 based on the determined torque distribution. For example, when starting the internal combustion engine 10, the processing circuit 101 causes the first motor generator 71 to function as a starter. Specifically, the control device 100 rotates the sun gear 41 by the first motor generator 71 to rotate the crankshaft 14 and start the internal combustion engine 10. At this time, the reaction force acting on the ring gear shaft 45 from the internal combustion engine 10 is canceled by the torque of the second motor generator 72.

[0018] When a predetermined stop condition is satisfied, the processing circuit 101 automatically stops the operation of the internal combustion engine 10, and executes intermittent operation control to automatically start the internal combustion engine 10 when a predetermined start condition is satisfied. That is, the processing circuit 101 repeatedly performs the operation and the operation stop of the internal combustion engine 10 according to the driving situation of the hybrid vehicle 1.

[0019] <Regarding the first diagnosis and the second diagnosis> Next, the first diagnosis executed by the processing circuit 101 will be described. The first diagnosis is a process of diagnosing the presence or absence of a defect in the filter 23 using the data of the front-rear differential pressure.

[0020] When a predetermined first condition, which is an appropriate condition in the acquisition of the front-rear differential pressure data, is satisfied, the processing circuit 101 repeatedly executes the process of acquiring the front-rear differential pressure data. The predetermined first condition includes that the engine rotational speed NE of the internal combustion engine 10 is equal to or higher than a predetermined value, the warm-up of the internal combustion engine 10 is completed, the intake air amount is equal to or higher than a predetermined value, and the like.

[0021] The processing circuit 101 acquires a detection signal for the front-to-rear differential pressure from the differential pressure sensor 83 as part of the process of acquiring front-to-rear differential pressure data. Based on the acquired detection signal for the front-to-rear differential pressure, the processing circuit 101 calculates the front-to-rear differential pressure data. The processing circuit 101 stores the calculated front-to-rear differential pressure data in the storage device 102. The storage device 102 can store multiple front-to-rear differential pressure data. When the processing circuit 101 has acquired a predetermined first number of front-to-rear differential pressure data, it performs a first diagnosis, which is a process of diagnosing whether or not there is a defect in the filter using the front-to-rear differential pressure data. The processing circuit 101 calculates the average value of the front-to-rear differential pressure data by averaging the acquired front-to-rear differential pressure data.

[0022] If the average value of the differential pressure across the front and rear is greater than or equal to a predetermined value, the processing circuit 101 performs a normal judgment as its first diagnosis, which means that there are no defects in the filter 23. If the average value of the differential pressure across the front and rear is less than a predetermined value, the processing circuit 101 performs an abnormal judgment as its first diagnosis, which means that there are defects in the filter 23.

[0023] The processing circuit 101 may perform the first diagnosis using a value other than the average value of the differential pressure data. For example, the processing circuit 101 may perform the first diagnosis based on whether the mode of the differential pressure data stored in the storage device 102 is greater than or equal to a predetermined value.

[0024] The processing circuit 101 sets the "First Diagnosis Performed" flag to "ON" when it has performed the first diagnosis. The "First Diagnosis Performed" flag indicates whether or not the first diagnosis has been performed. When the "First Diagnosis Performed" flag is "ON", it indicates that the processing circuit 101 has performed the first diagnosis. When the "First Diagnosis Performed" flag is "OFF", it indicates that the processing circuit 101 has not performed the first diagnosis. The "First Diagnosis Performed" flag is set to "OFF" at the start of the trip. The "First Diagnosis Performed" flag may also be set to "OFF" at the end of the trip.

[0025] Next, the second diagnosis performed by the processing circuit 101 will be described. The second diagnosis is a process that diagnoses whether or not there is an air-fuel ratio imbalance between multiple cylinders. There are individual differences in the injection characteristics of the fuel injectors 17. Therefore, even if the same amount of fuel injection is commanded to each of the fuel injectors 17 of multiple cylinders 11, the amount of fuel actually injected by the fuel injectors 17 of the multiple cylinders 11 may vary. As a result, variations in the air-fuel ratio of the multiple cylinders 11 may occur, which can worsen the emissions of the internal combustion engine 10.

[0026] The processing circuit 101 performs active control to change the fuel injection amount in a target cylinder among the multiple cylinders 11 of the internal combustion engine 10. The processing circuit 101 performs active control when a default second condition, which is an appropriate condition for performing active control, is met. The default second condition is that the engine rotational speed NE of the internal combustion engine 10 is equal to or greater than a default value, that the internal combustion engine 10 has finished warming up, and that the intake air amount is equal to or greater than a default value. The default first condition and the default second condition may be the same condition.

[0027] If there is no difference in air-fuel ratio between the target cylinder and the other cylinders 11 before the start of active control, the processing circuit 101 will execute active control, causing an imbalance in the air-fuel ratio between multiple cylinders. When an imbalance occurs in the air-fuel ratio between multiple cylinders, the rotational fluctuation of the crankshaft 14 increases.

[0028] If there is an air-fuel ratio mismatch between the target cylinder and the other cylinders 11 before the start of active control, the processing circuit 101 performs active control to reduce or increase the air-fuel ratio imbalance between the target cylinder and the other cylinders 11. If the air-fuel ratio imbalance between multiple cylinders is reduced, the rotational fluctuation of the crankshaft 14 decreases. If the air-fuel ratio imbalance between multiple cylinders increases, the rotational fluctuation of the crankshaft 14 increases.

[0029] The processing circuit 101 repeatedly acquires data on the rotational fluctuations of the crankshaft 14 while active control is being performed. Based on the rotational fluctuations of the crankshaft 14 during the active control, the processing circuit 101 performs a second diagnosis to diagnose whether there is an air-fuel ratio imbalance between multiple cylinders.

[0030] The processing circuit 101 sets the "Second Diagnosis Executed" flag to "ON" when it has executed the second diagnosis. The "Second Diagnosis Executed" flag indicates whether or not the second diagnosis has been executed. When the "Second Diagnosis Executed" flag is "ON", it indicates that the processing circuit 101 has executed the second diagnosis. When the "Second Diagnosis Executed" flag is "OFF", it indicates that the processing circuit 101 has not executed the second diagnosis. The "Second Diagnosis Executed" flag is set to "OFF" at the start of the trip. The "Second Diagnosis Executed" flag may also be set to "OFF" at the end of the trip.

[0031] Next, we will describe the series of processes by which the processing circuit 101 performs the first diagnosis and the second diagnosis. The processing circuit 101 repeatedly performs this series of processes until both the first diagnosis completed flag and the second diagnosis completed flag are "ON".

[0032] As shown in Figure 2, when this series of processes is started, the processing circuit 101 determines in step S10 whether or not it has acquired a predetermined first number of front-to-back differential pressure data. If the processing circuit 101 has not acquired a predetermined first number of front-to-back differential pressure data (step S10: NO), it proceeds to step S13. The processing in step S13 will be described later. If the processing circuit 101 has acquired at least a predetermined first number of front-to-back differential pressure data (step S10: YES), it proceeds to step S11. In step S11, the processing circuit 101 performs a first diagnosis. After that, the processing circuit 101 proceeds to step S12. In step S12, the processing circuit 101 sets the first diagnosis completed flag to "ON". After that, the processing circuit 101 proceeds to step S13.

[0033] In step S13, the processing circuit 101 determines whether it has acquired a predetermined second number of rotational fluctuation data. If the processing circuit 101 has not acquired a predetermined second number of rotational fluctuation data (step S13: NO), it terminates the series of processes shown in Figure 2. If the processing circuit 101 has acquired at least a predetermined second number of rotational fluctuation data (step S13: YES), it proceeds to step S14. In the process of step S14, the processing circuit 101 performs a second diagnosis. After that, the processing circuit 101 proceeds to step S15. In the process of step S15, the processing circuit 101 sets the second diagnosis completed flag to "ON". After that, the processing circuit 101 terminates the series of processes shown in Figure 2.

[0034] <Regarding the process for acquiring differential pressure data and active control> Next, with reference to Figure 3, a series of processes that determine whether or not to acquire differential pressure data and whether or not to perform active control will be described for reference. This series of processes is repeatedly performed during the operation of the internal combustion engine 10. When the processing circuit 101 acquires differential pressure data, it is preferable that the flow rate of exhaust gases flowing through the exhaust passage 21 is stable. On the other hand, when the processing circuit 101 is performing active control, the fluctuation in the flow rate of exhaust gases flowing through the exhaust passage 21 may increase with increasing rotational fluctuations of the crankshaft 14. Therefore, in this series of processes, the processing circuit 101 does not perform the process of acquiring differential pressure data and active control simultaneously.

[0035] As shown in Figure 3, when this series of processes is started, the processing circuit 101 determines whether a predetermined first condition is met in the process of step S20. The predetermined first condition is the appropriate condition for acquiring differential pressure data. If the predetermined first condition is not met (step S20: NO), the processing circuit 101 proceeds to step S25. Step S25 will be described later. If the predetermined first condition is met (step S20: YES), the processing circuit 101 proceeds to step S21.

[0036] In step S21, the processing circuit 101 acquires the differential pressure data across the entire system. After that, the processing circuit 101 proceeds to step S22. In step S22, the processing circuit 101 determines whether or not it has acquired a predetermined first number of differential pressure data across the entire system. If the processing circuit 101 has not acquired a predetermined first number of differential pressure data across the entire system (step S22: NO), it proceeds to step S23.

[0037] In the process of step S23, the processing circuit 101 determines whether the predetermined first condition is met, similar to the process of step S20. If the predetermined first condition is met (step S23: YES), the processing circuit 101 proceeds to step S21. In other words, if the predetermined first condition is met (step S23: YES), the processing circuit 101 proceeds to step S21. As a result, the processing circuit 101 repeatedly acquires the data for the differential pressure across the front and rear until it acquires the predetermined first number of differential pressure data (step S22: YES).

[0038] If the processing circuit 101 has acquired a predetermined first number or more of differential pressure data in step S22 (step S22: YES), it proceeds to step S24. If the processing circuit 101 has not met the predetermined first condition in step S23 (step S23: NO), it also proceeds to step S24. In step S24, the processing circuit 101 finishes acquiring the differential pressure data. After that, the processing circuit 101 proceeds to step S25.

[0039] In step S25, the processing circuit 101 determines whether the default second condition is met. The default second condition is an appropriate condition for the execution of active control. If the default second condition is not met (step S25: NO), the processing circuit 101 terminates the series of processes shown in Figure 3. If the default second condition is met (step S25: YES), the processing circuit 101 proceeds to step S26.

[0040] In step S26, the processing circuit 101 performs active control. Furthermore, while performing active control, the processing circuit 101 performs a process to acquire data on the rotational fluctuations of the crankshaft 14. After that, the processing circuit 101 proceeds to step S27.

[0041] In step S26, the processing circuit 101 determines whether or not it has acquired a predetermined second number of rotational fluctuation data. If the processing circuit 101 has not acquired a predetermined second number of rotational fluctuation data (step S27: NO), it proceeds to step S28.

[0042] In the process of step S28, the processing circuit 101 determines whether the default second condition is met, similar to the process of step S25. If the default second condition is met (step S28: YES), the processing circuit 101 proceeds to step S26. That is, if the default second condition is met, the processing circuit 101 continues to execute active control and repeatedly executes the process of acquiring rotational fluctuation data until it acquires a default second number of rotational fluctuation data.

[0043] In step S27, if the processing circuit 101 has acquired a predetermined second number or more of rotational fluctuation data (step S27: YES), it proceeds to step S29. In step S28, if the predetermined second condition is not met (step S28: NO), the processing circuit 101 also proceeds to step S29. In step S29, the processing circuit 101 terminates the active control and the process of acquiring rotational fluctuation data. After that, the processing circuit 101 temporarily terminates the series of processes shown in Figure 3.

[0044] <Operation of the First Embodiment> The processing circuit 101 of the control device 100 does not perform active control while it is performing the process of acquiring differential pressure data. While the processing circuit 101 is performing the process of acquiring differential pressure data, there are no fluctuations in the exhaust flow rate in the exhaust passage 21 that may be caused by active control. Therefore, the processing circuit 101 can acquire differential pressure data accurately.

[0045] <Effects of the First Embodiment> (1-1) The processing circuit 101 of the control device 100 can accurately acquire differential pressure data, thereby suppressing deterioration in the accuracy of the process for diagnosing whether or not there is a defect in the filter 23.

[0046] (1-2) The hybrid vehicle 1 repeatedly operates and stops the internal combustion engine 10 depending on the driving conditions. When the internal combustion engine 10 is stopped, exhaust gas does not flow into the exhaust passage 21, making it an unsuitable state for acquiring the differential pressure between the front and rear. When the internal combustion engine 10 is stopped, active control cannot be performed, making it an unsuitable state for acquiring rotational fluctuation data. The processing circuit 101 needs to acquire differential pressure data between the front and rear and perform active control when the internal combustion engine 10 is operating. When the internal combustion engine 10 is operating, the processing circuit 101 performs either the process of acquiring differential pressure data between the front and rear or the process of performing active control. As a result, the control device 100 can secure many opportunities to accurately acquire differential pressure data between the front and rear and rotational fluctuation data of the crankshaft 14 in the hybrid vehicle 1, where the period of operation of the internal combustion engine 10 is short.

[0047] (1-3) The processing circuit 101 executes a process to acquire differential pressure data if both the default first condition and the default second condition are met. If the processing circuit 101 has acquired differential pressure data, it does not perform active control even if the default second condition is met. Therefore, the processing circuit 101 can acquire differential pressure data with high accuracy. As a result, the control device 100 can suppress a deterioration in the accuracy of the process for diagnosing whether or not there is a defect in the filter 23.

[0048] <Example of modification of the first embodiment> The first embodiment described above can be implemented with the following modifications. The above first embodiment and the following examples of modifications to the first embodiment can be combined with each other to the extent that they do not contradict each other technically.

[0049] The processing circuit 101 may determine whether the default second condition is met before determining whether the default first condition is met, in a series of processes that determine whether to acquire differential pressure data and whether to perform active control. In that case, the processing circuit 101 performs the processes shown in Figure 4 as a series of processes that determine whether to acquire differential pressure data and whether to perform active control.

[0050] As shown in Figure 4, in this series of processes, the processing circuit 101 executes the processes from step S25 to step S29 before the processes from step S20 to step S24. In this case, the processing circuit 101 executes active control if both the default first condition and the default second condition are met. When the processing circuit 101 is executing active control, it does not execute the process of acquiring the differential pressure data even if the default first condition is met. Therefore, the processing circuit 101 can acquire the differential pressure data with high accuracy. As a result, the control device 100 can reduce the possibility of acquiring low-accuracy differential pressure data, thereby suppressing a deterioration in the accuracy of diagnosing the presence or absence of defects in the filter 23.

[0051] (Second Embodiment) Next, the second embodiment will be described with reference to Figures 5 and 6. The second embodiment will be described focusing on the differences from the first embodiment. In the second embodiment, the processing circuit 101 does not perform active control until the first diagnosis is completed. The processing circuit 101 performs the processes shown in Figures 5 and 6 as a series of processes to determine whether or not to perform the first diagnosis and whether or not to perform the second diagnosis. The processing circuit 101 repeatedly performs this series of processes while the internal combustion engine 10 is in operation.

[0052] As shown in Figure 5, when this series of processes is started, the processing circuit 101 determines in step S40 whether the first diagnostic completed flag is "ON". If the first diagnostic completed flag is "ON" (step S40: YES), the processing circuit 101 proceeds to step S47 shown in Figure 6. Step S47 will be described later. If the first diagnostic completed flag is not "ON" (step S40: NO), the processing circuit 101 proceeds to step S41 shown in Figure 5. In step S41, the processing circuit 101 determines whether the default first condition is met. If the default first condition is not met (step S41: NO), the processing circuit 101 repeatedly executes the process in step S41 until the default first condition is met. If the default first condition is met (step S41: YES), the processing circuit 101 proceeds to step S42. In step S42, the processing circuit 101 acquires differential pressure data across the entire system, similar to step S21 in Figure 3. After that, the processing circuit 101 proceeds to step S43.

[0053] In step S43, the processing circuit 101 determines whether or not it has acquired a predetermined first number of front-to-back differential pressure data. If the processing circuit 101 has not acquired a predetermined first number of front-to-back differential pressure data (step S43: NO), it proceeds to step S45.

[0054] In step S45, the processing circuit 101 determines whether the predetermined first condition is met, similar to the process in step S41. If the predetermined first condition is not met in step S45 (step S45: NO), the processing circuit 101 proceeds to step S46. In step S46, the processing circuit 101 terminates the process of acquiring the differential pressure data. After that, the processing circuit 101 proceeds to step S41. That is, the processing circuit 101 attempts to acquire differential pressure data until it acquires the predetermined first number of differential pressure data.

[0055] If the processing circuit 101 finds that the predetermined first condition is met in step S45 (step S45: YES), it proceeds to step S42. That is, if the predetermined first condition is met, the processing circuit 101 repeatedly acquires the differential pressure data until it obtains a predetermined first number of differential pressure data.

[0056] If the processing circuit 101 has acquired a predetermined number or more of differential pressure data in step S43 (step S43: YES), it proceeds to step S44. In step S44, the processing circuit 101 finishes acquiring differential pressure data. After that, the processing circuit 101 proceeds to step S11.

[0057] In step S11, the processing circuit 101 performs a first diagnosis. After that, the processing circuit 101 proceeds to step S12. In step S12, the processing circuit 101 sets the "first diagnosis completed" flag to "ON". After that, the processing circuit 101 proceeds to step S47 shown in Figure 6.

[0058] As shown in Figure 6, in step S47, the processing circuit 101 determines whether the second diagnosis completed flag is "ON". If the second diagnosis completed flag is "ON" (step S47: YES), the processing circuit 101 terminates the series of processes shown in Figures 5 and 6. If the second diagnosis completed flag is not "ON" (step S47: NO), the processing circuit 101 proceeds to step S48.

[0059] In step S48, the processing circuit 101 determines whether the default second condition is met. If the default second condition is not met (step S48: NO), the processing circuit 101 repeatedly executes the process in step S48 until the default second condition is met. If the default second condition is met (step S48: YES), the processing circuit 101 proceeds to step S49. The process in step S49 shown in Figure 6 is the same as the process in step S26 shown in Figure 3. After that, the processing circuit 101 proceeds to step S50. In step S50, the processing circuit 101 determines whether the default second number of rotational fluctuation data has been acquired. If the default second number of rotational fluctuation data has not been acquired (step S50: NO), the processing circuit 101 proceeds to step S52.

[0060] In step S52, the processing circuit 101 determines whether the default second condition is met, similar to the process in step S48. If the default second condition is not met in step S52 (step S52: NO), the processing circuit 101 proceeds to step S53. In step S53, the processing circuit 101 terminates the active control and the process of acquiring rotational fluctuation data. After that, the processing circuit 101 proceeds to step S48. That is, the processing circuit 101 attempts to execute active control and acquire rotational fluctuation data until it acquires the default second number of rotational fluctuation data.

[0061] If the default second condition is met during the processing in step S52 (step S52: YES), the processing circuit 101 proceeds to step S49. That is, if the default second condition is met, the processing circuit 101 repeatedly performs the acquisition of rotational fluctuation data until a default second number of rotational fluctuation data is acquired.

[0062] If the processing circuit 101 has acquired a predetermined second or greater number of rotational fluctuation data in step S50 (step S50: YES), it proceeds to step S51. In step S51, the processing circuit 101 terminates the active control and the process of acquiring rotational fluctuation data. After that, the processing circuit 101 proceeds to step S14. In step S14, the processing circuit 101 performs the second diagnosis. After that, the processing circuit 101 proceeds to step S15. In step S15, the processing circuit 101 sets the second diagnosis completed flag to "ON". After that, the processing circuit 101 terminates the series of processes shown in Figures 5 and 6.

[0063] <Operation of the second embodiment> If the first determination has not been performed, the processing circuit 101 determines whether the default first condition is met, rather than whether the default second condition is met. Therefore, the processing circuit 101 does not perform active control until the execution of the first determination is complete. While the processing circuit 101 is performing the process of acquiring the differential pressure data, there are no fluctuations in the exhaust flow rate in the exhaust passage 21 that may be caused by active control. Therefore, the processing circuit 101 can acquire the differential pressure data accurately.

[0064] <Effects of the second embodiment> (2-1) The processing circuit 101 of the control device 100 can accurately acquire differential pressure data, thereby suppressing deterioration in the accuracy of the process for diagnosing whether or not there is a defect in the filter 23.

[0065] (2-2) The control device 100 can prioritize the first diagnosis, which diagnoses whether or not there is a defect in the filter 23, over the second diagnosis, which diagnoses whether or not there is an air-fuel ratio imbalance in multiple cylinders 11.

[0066] <Example of modification of the second embodiment> The above second embodiment can be implemented with the following modifications. The above second embodiment and the following examples of modifications to the second embodiment can be combined with each other to the extent that they do not contradict each other technically.

[0067] The processing circuit 101 does not need to perform the process of acquiring differential pressure data until the second diagnosis is completed. In that case, the processing circuit 101 executes the processes shown in Figures 7 and 8 as a series of processes to determine whether or not to perform the first diagnosis and whether or not to perform the second diagnosis.

[0068] As shown in Figures 7 and 8, the processing circuit 101 executes steps S14, S15, and steps S47 to S53 before steps S11, S12, and steps S40 to S46. In this case, if the second determination has not been performed, the processing circuit 101 determines whether the default second condition is met, rather than whether the default first condition is met. Therefore, the processing circuit 101 does not acquire differential pressure data until the execution of the second determination is completed. As a result, the control device 100 can prioritize the execution of the second diagnosis, which diagnoses whether there is an air-fuel ratio imbalance in multiple cylinders 11, over the first diagnosis, which diagnoses whether there is a defect in the filter 23.

[0069] <Other examples of changes> The following are some elements that can be modified in common with each of the above embodiments. The following examples of modifications can be combined with each other to the extent that they do not contradict each other technically.

[0070] The settings of the processing circuit 101 of the control device 100 are not limited to the embodiments and modification examples described above. The processing circuit 101 of the control device 100 only needs to be set to execute either the process of acquiring differential pressure data or active control when the default first condition is met and the default second condition is also met.

[0071] The processing circuit 101 may be configured to prioritize determining whether the default first condition is met or whether the default second condition is met if neither the first diagnosis nor the second diagnosis has been completed. For example, the processing circuit 101 may be configured to determine only whether the default first condition is met if neither the first diagnosis nor the second diagnosis has been completed. For example, the processing circuit 101 may be configured to determine only whether the default second condition is met if neither the first diagnosis nor the second diagnosis has been completed.

[0072] The control device 100 may be configured as a circuit including one or more processors that execute various processes according to a computer program (software). Alternatively, the control device 100 may be configured as a circuit including one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), or a combination thereof, that execute at least some of the various processes. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer. [Explanation of Symbols]

[0073] 1...Hybrid vehicle, 10...Internal combustion engine, 11...Cylinder, 14...Crankshaft, 21...Exhaust passage, 23...Filter, 62...Drive shaft, 77...Battery, 83...Differential pressure sensor, 100...Control device, 101...Processing circuit

Claims

1. A control device applicable to a hybrid vehicle, comprising an internal combustion engine and a motor generator as power sources for driving the drive shaft, a battery for charging the power generated by the motor generator using the output of the internal combustion engine, an exhaust passage for guiding exhaust from the internal combustion engine to the rear of the vehicle, a filter for collecting particulate matter contained in the exhaust, and a differential pressure sensor for detecting the front-to-rear differential pressure, which is the difference between the pressure upstream of the filter and the pressure downstream of the filter, Equipped with a processing circuit, The aforementioned processing circuit When the predetermined first condition is met, the process of acquiring the differential pressure data is repeatedly executed, and when the differential pressure data is acquired a predetermined first number of times, the first diagnosis is performed, which is a process of diagnosing whether or not there is a defect in the filter using the differential pressure data. If the default second condition is met, an active control is performed to change the fuel injection amount in the target cylinder among the multiple cylinders of the internal combustion engine, and while the active control is being performed, a process to acquire data on the rotational fluctuations of the crankshaft is repeatedly performed, and when a default second number of rotational fluctuation data have been acquired, a second diagnosis is performed, which is a process to diagnose whether or not there is an air-fuel ratio imbalance between the multiple cylinders using the rotational fluctuation data. The process of acquiring the differential pressure data and the active control are not performed simultaneously. Control system for hybrid vehicles.

2. If both the first and second default conditions are met, the process of acquiring the differential pressure data is executed. A control device for a hybrid vehicle according to claim 1.

3. If both the first and second default conditions are met, the active control is executed. A control device for a hybrid vehicle according to claim 1.

4. The active control will not be executed until the first diagnosis is completed. A control device for a hybrid vehicle according to claim 1.

5. Until the second diagnosis is completed, the process of acquiring the differential pressure data will not be executed. A control device for a hybrid vehicle according to claim 1.

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