Control device and control method for hybrid vehicle

Abstract

The present invention provides a control device and a control method for a hybrid vehicle, wherein the control device for the hybrid vehicle includes an engine ECU and an HVECU. The engine ECU executes a partial cylinder fuel cut-off control that stops supplying fuel to one or more cylinders and supplies fuel to the remaining cylinders, and sends control information of the partial cylinder fuel cut-off control to the HVECU. The HVECU executes a driving force compensation control to compensate for the decrease in driving force of a multi-cylinder engine caused by the execution of the partial cylinder fuel cut-off control by using the driving force of an electric generator. The engine ECU prohibits the execution of the partial cylinder fuel cut-off control when there is a possibility of abnormality in the transmission and reception of the control information of the partial cylinder fuel cut-off control.

Description

Technical Field

[0001] The present disclosure relates to a control device and a control method for a hybrid vehicle. Background Art

[0002] In the past, as disclosed in Japanese Patent Gazette No. 2018-65448, there is a known hybrid vehicle that has a multi-cylinder internal combustion engine and an electric motor and has a collector in the exhaust system of the internal combustion engine for collecting particulate matter (hereinafter referred to as "PM") such as soot contained in the exhaust gas. In this hybrid vehicle, regeneration control of the collector is implemented regularly. In the regeneration control of the collector, a fuel cut is implemented to stop the fuel supply to at least one cylinder of the internal combustion engine. At this time, air containing oxygen is supplied to the collector to increase the temperature of the collector. As a result, the PM is burned and the collector is regenerated.

[0003] In addition, as disclosed in Japanese Patent Publication No. 2009-248698, as a control device for a hybrid vehicle with a multi-cylinder internal combustion engine and an electric motor, there is known a control device including an engine electronic control unit for controlling the internal combustion engine and a HV electronic control unit for controlling the vehicle. In this control device, when the required power relative to the internal combustion engine becomes less than a threshold value, the engine electronic control unit implements a fuel cutoff to stop the fuel supply to each cylinder of the internal combustion engine, and sends the fuel cutoff implementation information to the HV electronic control unit. In addition, when the HV electronic control unit receives the fuel cutoff implementation information, it calculates the insufficient driving force due to the fuel cutoff. And, the HV electronic control unit outputs the insufficient driving force to the electric motor at a timing after the correction start time from the fuel cutoff start timing.

[0004] When the catalyst of the exhaust system of a multi-cylinder internal combustion engine is heated up by fuel cutoff, sometimes anomalies occur in the transmission and reception of fuel cutoff control information between the engine electronic control unit and the HV electronic control unit. For example, there are communication anomalies such as delays and interruptions in the transmission and reception of information on whether fuel cutoff can be implemented, and data related to the crankshaft position of the fuel cutoff cylinder where fuel cutoff is implemented. In such a case, it is impossible to compensate the driving force reduction caused by fuel cutoff by the driving force of the electric motor at an appropriate timing. Therefore, it is impossible to synchronize the driving force reduction caused by fuel cutoff and the driving force compensation based on the electric motor, and the driving force applied to the drive wheel changes, which may lead to a deterioration in driving performance. Summary of the invention

[0005] The object of the present invention is to suppress the change in driving force caused by the decrease in driving force due to the fuel cut-off and the asynchronous driving force compensation based on the electric motor when a communication abnormality occurs between electronic control units when the catalyst of the exhaust system of a multi-cylinder internal combustion engine is heated by cutting off the fuel so as to stop the fuel supply to at least one cylinder.

[0006] In order to solve the above-mentioned problems, according to a first aspect of the present invention, a control device for a hybrid vehicle is provided. The hybrid vehicle includes a multi-cylinder internal combustion engine and an electric motor provided with a catalyst for purifying exhaust gas in an exhaust system. The hybrid vehicle is configured to transmit driving force from the multi-cylinder internal combustion engine and the electric motor to driving wheels. The control device includes a first electronic control unit and a second electronic control unit. The first electronic control unit is configured to execute partial cylinder fuel cut-off control in which fuel supply to at least one cylinder is stopped and fuel is supplied to the remaining cylinders except the at least one cylinder, and to send control information of the partial cylinder fuel cut-off control to the second electronic control unit. The second electronic control unit is configured to execute driving force compensation control to control the electric motor based on the received control information of the partial cylinder fuel cut-off control, so as to compensate the driving force reduction of the multi-cylinder internal combustion engine caused by the execution of the partial cylinder fuel cut-off control with the driving force of the electric motor. The first electronic control unit is further configured to prohibit the execution of the partial cylinder fuel cut-off control when there is a possibility that an abnormality may occur in the transmission and reception of the control information of the partial cylinder fuel cut-off control between the first electronic control unit and the second electronic control unit.

[0007] According to the present invention, when there is a possibility of abnormality in the transmission and reception of control information of the partial cylinder fuel cut-off control between the first electronic control unit that executes the partial cylinder fuel cut-off control and the second electronic control unit that executes the driving force compensation control, the first electronic control unit prohibits the execution of the partial cylinder fuel cut-off control. Therefore, it is possible to suppress the driving force drop caused by the fuel cut-off and the driving force variation caused by the asynchronous driving force compensation based on the electric motor.

[0008] Preferably, the control device of the hybrid vehicle mentioned above also includes a third electronic control unit, the second electronic control unit is configured to calculate an instruction value for compensating for a reduction in driving force of the multi-cylinder internal combustion engine by utilizing the driving force of the electric motor based on the received control information of the partial cylinder fuel cut-off control, and send the instruction value to the third electronic control unit, the third electronic control unit is configured to drive and control the electric motor according to the received instruction value, and the first electronic control unit is further configured to prohibit execution of the partial cylinder fuel cut-off control when there is a possibility of abnormality in the transmission and reception of the instruction value between the second electronic control unit and the third electronic control unit.

[0009] According to the present invention, when there is a possibility of abnormality in the transmission and reception of command values ​​between a second electronic control unit that calculates a command value for compensating for a decrease in the driving force of a multi-cylinder internal combustion engine by using the driving force of an electric motor and a third electronic control unit that drives and controls the electric motor according to the command value, the first electronic control unit prohibits execution of a partial cylinder fuel cut-off control. Thus, it is possible to suppress the change in driving force caused by the decrease in driving force due to fuel cut-off and the asynchronous driving force compensation based on the electric motor.

[0010] In the control device of the above-mentioned hybrid vehicle, it is preferred that the first electronic control unit is configured to allow the partial cylinder fuel cut-off control to be executed when the speed of the multi-cylinder internal combustion engine is above a predetermined speed even when there is a possibility of abnormality in the reception and transmission of control information of the partial cylinder fuel cut-off control between the first electronic control unit and the second electronic control unit.

[0011] According to the present invention, the first electronic control unit allows the execution of the partial cylinder fuel cutoff control when the speed of the multi-cylinder internal combustion engine is above a predetermined speed, even if there is a possibility that an abnormality may occur in the transmission and reception of the control information of the partial cylinder fuel cutoff control between the first electronic control unit and the second electronic control unit. When the speed of the multi-cylinder internal combustion engine is above the predetermined speed, the change in the driving force itself is smaller than when the speed is less than the predetermined speed. Therefore, by "allowing the execution of the partial cylinder fuel cutoff control when the speed of the multi-cylinder internal combustion engine is above the predetermined speed, even if there is a possibility that an abnormality may occur in the transmission and reception of the control information of the partial cylinder fuel cutoff control between the first electronic control unit and the second electronic control unit", it is possible to achieve a balance between suppressing the change in driving force and executing the partial cylinder fuel cutoff.

[0012] In order to solve the above-mentioned problems, according to a second aspect of the present invention, a control method for a hybrid vehicle is provided. The hybrid vehicle includes a multi-cylinder internal combustion engine provided with a catalyst for purifying exhaust gas in an exhaust system, an electric motor, a first electronic control unit, and a second electronic control unit. The hybrid vehicle is configured to transmit driving force from the multi-cylinder internal combustion engine and the electric motor to driving wheels. The control method includes the following steps: using the first electronic control unit, executing partial cylinder fuel cut-off control in which fuel supply to at least one cylinder is stopped and fuel is supplied to the remaining cylinders except the at least one cylinder, and sending control information of the partial cylinder fuel cut-off control to the second electronic control unit; using the second electronic control unit, executing driving force compensation control to control the electric motor based on the received control information of the partial cylinder fuel cut-off control, so as to compensate the driving force reduction of the multi-cylinder internal combustion engine caused by the execution of the partial cylinder fuel cut-off control with the driving force of the electric motor; and prohibiting the first electronic control unit from executing the partial cylinder fuel cut-off control when there is a possibility of abnormality in the transmission and reception of the control information of the partial cylinder fuel cut-off control between the first electronic control unit and the second electronic control unit.

[0013] According to the present invention, when there is a possibility of abnormality in the transmission and reception of control information of the partial cylinder fuel cut-off control between the first electronic control unit that executes the partial cylinder fuel cut-off control and the second electronic control unit that executes the driving force compensation control, the first electronic control unit is prohibited from executing the partial cylinder fuel cut-off control. Therefore, it is possible to suppress the driving force drop caused by the fuel cut-off and the driving force fluctuation caused by the asynchronous driving force compensation based on the electric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a schematic structural diagram showing a vehicle of the present disclosure.

[0015] Figure 2 It is shown Figure 1 Schematic diagram of the structure of a multi-cylinder engine.

[0016] Figure 3 is exemplified in Figure 1 Flowchart of a routine for determining whether or not the particulate trap needs to be regenerated, executed in a vehicle.

[0017] Figure 4 is exemplified in Figure 1 Flowchart of a partial cylinder fuel cutoff control routine executed in a vehicle.

[0018] Figure 5 is exemplified in Figure 1 Flowchart of a driving force compensation control routine executed in a vehicle. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0020] Figure 1 1 is a schematic diagram showing a hybrid vehicle 1 as a vehicle of the present disclosure. The hybrid vehicle 1 shown in the figure includes a multi-cylinder engine (hereinafter referred to as "engine") 10 including a plurality of (for example, four in the present embodiment) cylinders (combustion chambers) 11, a single pinion type planetary gear 30, electric generators MG1 and MG2, both of which are synchronous electric generators (three-phase AC motors), an electric storage device (battery) 40, a power control device (hereinafter referred to as "PCU") 50 connected to the electric storage device 40 and driving the electric generators MG1 and MG2, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 60 that controls the entire vehicle.

[0021] Figure 2 It is shown Figure 1 Schematic diagram of the structure of the engine 10. The engine 10 is an in-line gasoline engine (internal combustion engine) that converts the reciprocating motion of a piston (not shown) accompanying the combustion of a mixture of hydrocarbon fuel and air in a plurality of cylinders 11 into the rotational motion of a crankshaft (output shaft) 12. The engine 10 includes an intake pipe 13, an intake manifold 13m, a throttle 14, a plurality of in-cylinder injection valves 15, a plurality of intake valves and a plurality of exhaust valves (not shown), a plurality of spark plugs 16, an exhaust manifold 17m, and an exhaust pipe 17. One end of the intake manifold 13m is connected to the intake pipe 13, and the other end is connected to the intake port of each cylinder 11. The throttle 14 is an electronically controlled throttle that can change the passage area of ​​the intake pipe 13. Each in-cylinder injection valve 15 directly injects fuel into the corresponding cylinder 11. Each spark plug 16 ignites the mixture of fuel and air in the cylinder 11 by discharging to the corresponding cylinder 11. One end of the exhaust manifold 17 m is connected to the exhaust port of each cylinder 11 , and the other end is connected to the exhaust pipe 17 .

[0022] In addition, the engine 10 includes a fuel tank Tk for storing fuel, a delivery pipe DH for distributing fuel to a plurality of in-cylinder injection valves 15, a fuel supply pipe LH for supplying fuel to the delivery pipe DH, and a pump Pf for sucking fuel from the fuel tank Tk to the fuel supply pipe LH. The pump Pf is an electric pump driven by power from an auxiliary battery (not shown). It should be noted that the pump Pf may also be a mechanical pump driven by the engine 10.

[0023] In addition, the engine 10 is provided with an upstream purification device 18 and a downstream purification device 19 in the exhaust pipe 17. The upstream purification device 18 includes a NOx storage type exhaust purification catalyst (three-way catalyst) 180 for purifying harmful components such as CO (carbon monoxide), HC, and NOx in the exhaust gas from each cylinder 11. In addition, the downstream purification device 19 is arranged on the downstream side of the upstream purification device 18, and includes a particulate trap (GPF) 190 for trapping particulate matter (particles) in the exhaust gas. In the present embodiment, the particulate trap 190 carries a NOx storage type exhaust purification catalyst (three-way catalyst).

[0024] The engine 10 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 90. The engine ECU 90 includes a microcomputer having a CPU, ROM, RAM, input and output interfaces, etc., which are not shown in the figure, various drive circuits, various logic ICs, etc., and performs intake air quantity control, fuel injection control, and ignition timing control of the engine 10. In addition, the engine ECU 90 receives detection values ​​of a crank angle sensor 80, a water temperature sensor 81, an air flow meter 82, a throttle position sensor, which is not shown in the figure, an upstream air-fuel ratio sensor 85, a downstream air-fuel ratio sensor 86, a differential pressure sensor 87, an upstream catalyst temperature sensor 88, a downstream catalyst temperature sensor 89, etc., via an input port, which is not shown in the figure.

[0025] The crank angle sensor 80 detects the rotation position (crank position) of the crankshaft 12. The water temperature sensor 81 detects the cooling water temperature Tw of the cooling water flowing to the engine. The air flow meter 82 detects the intake air amount GA of the engine. The upstream throttle position sensor detects the angle (throttle position) of the throttle valve 14. The upstream air-fuel ratio sensor 85 detects the air-fuel ratio of the exhaust gas flowing between the exhaust manifold 17 and the upstream purification device 18, that is, the upstream air-fuel ratio AFf. The downstream air-fuel ratio sensor 86 detects the air-fuel ratio of the exhaust gas flowing between the upstream purification device 18 and the downstream purification device 19, that is, the downstream air-fuel ratio AFr. The differential pressure sensor 87 detects the differential pressure ΔP of the exhaust gas on the upstream side and the downstream side of the particulate trap 190. The upstream catalyst temperature sensor 88 detects the temperature (catalyst temperature) Tct of the upstream purification device 18 (exhaust purification catalyst 180). The downstream side catalyst temperature sensor 89 detects the temperature (trap temperature) Tpf of the downstream side purification device 19 (particulate trap 190 ).

[0026] The engine ECU 90 calculates the rotation speed Ne of the engine 10 (crankshaft 12) based on the crankshaft position from the crank angle sensor 80. In addition, the engine ECU 90 calculates the accumulation amount Dpm of particulate matter in the particulate trap 190 at predetermined intervals by at least one of the operation history method and the differential pressure method. When the operation history method is used, the engine ECU 90 adds the estimated increase amount of particulate matter or the estimated decrease amount of particulate matter based on the operation state of the engine 10 to the previous value of the accumulation amount Dpm to calculate the current value of the accumulation amount Dpm. The estimated increase amount of particulate matter is calculated, for example, as the product of the estimated discharge amount of particulate matter calculated based on the rotation speed Ne of the engine 10, the load factor and the cooling water temperature Tw, the discharge coefficient and the capture rate of the particulate trap 190. The estimated reduction amount of the particulate matter is calculated, for example, as the product of the combustion amount of the particulate matter calculated from the previous value of the accumulation amount Dpm, the inflow air flow rate, and the temperature Tpf of the particulate trap 190 and the correction coefficient. When the differential pressure method is used, the engine ECU 90 calculates the accumulation amount Dpm of the particulate matter accumulated in the particulate trap 190 based on the differential pressure ΔP detected by the differential pressure sensor 87.

[0027] It should be noted that the engine 10 may also be a diesel engine or an LPG engine including a diesel particulate filter (DPF). In addition, the engine 10 may be a port injection type that injects fuel into the port of each cylinder 11, or may have both an in-cylinder injection type and a port injection type that directly injects fuel into each cylinder 11. In addition, the temperatures Tct and Tpf of the exhaust purification catalyst 180 and the particulate filter 190 may also be estimated based on the intake air amount GA, the speed Ne, the temperature of the exhaust gas, the upstream air-fuel ratio AFf, the downstream air-fuel ratio AFr, etc.

[0028] like Figure 1 As shown, the planetary gear 30 is a differential rotation mechanism including a sun gear (first element) 31, a ring gear (second element) 32, and a planetary gear (third element) 34 that rotatably supports a plurality of pinion gears 33. The sun gear 31 is connected to the rotor of the motor generator MG1, and the planetary gear 34 is connected to the crankshaft 12 of the engine 10 via the damper mechanism 24. The ring gear 32 is integrated with a countershaft drive gear 35 as an output member, and the two rotate coaxially and integrally.

[0029] The counter drive gear 35 is connected to the left and right wheels (drive wheels) W via the counter driven gear 36 meshing with the counter drive gear 35, the final drive gear (drive pinion) 37 rotating integrally with the counter driven gear 36, the final driven gear (differential ring gear) 39r meshing with the final drive gear 37, the differential gear 39, and the drive shaft DS. Thus, the planetary gear 30, the gear train from the counter drive gear 35 to the final driven gear 39r, and the differential gear 39 constitute the transaxle 20 that transmits a part of the output torque of the engine 10 as a power generation source to the wheels W and connects the engine 10 and the motor generator MG1 to each other.

[0030] In addition, a drive gear 38 is fixed to the rotor of the motor generator MG2. The drive gear 38 has a smaller number of teeth than the counter driven gear 36, and meshes with the counter driven gear 36. Thus, the motor generator MG2 is connected to the left and right wheels W via the drive gear 38, the counter driven gear 36, the final drive gear 37, the final driven gear 39r, the differential gear 39, and the drive shaft DS.

[0031] The motor generator MG1 can work as a generator that converts at least a part of the power from the engine 10 running under load into electric power. The motor generator MG2 can work as an electric motor that is driven by at least one of the electric power from the power storage device 40 and the electric power from the motor generator MG1 to generate a driving torque on the drive shaft DS. That is, in the hybrid vehicle 1, the motor generator MG2 as a power generation source functions together with the engine 10 as a power generation device that outputs a driving torque (driving force) to the wheels W mounted on the drive shaft DS. Moreover, the motor generator MG2 outputs a regenerative braking torque when the hybrid vehicle 1 is braked. The motor generators MG1 and MG2 can exchange electric power with the power storage device 40 via the PCU 50 and exchange electric power with each other via the PCU 50.

[0032] The power storage device 40 is, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. The power storage device 40 is managed by a power management electronic control device (hereinafter referred to as "power management ECU") 45 including a microcomputer having a CPU, ROM, RAM, input / output interface, etc. (not shown). The power management ECU 45 derives the SOC (charging rate), the allowable charging power Win, the allowable discharging power Wout, etc. of the power storage device 40 based on the terminal voltage VB from the voltage sensor (not shown) of the power storage device 40, the charge / discharge current IB from the current sensor (not shown), the battery temperature Tb from the temperature sensor 47, etc.

[0033] The PCU 50 includes a first inverter 51 for driving the motor generator MG1, a second inverter 52 for driving the motor generator MG2, a converter (voltage conversion module) 53 capable of boosting the power from the power storage device 40 and lowering the power from the motor generators MG1 and MG2, etc. The PCU 50 is controlled by a motor electronic control unit (hereinafter referred to as "MGECU") 55 including a microcomputer having a CPU, ROM, RAM, input and output interfaces, etc. (not shown), various drive circuits, various logic ICs, etc. The MGECU 55 obtains a command signal from the HVECU 60, a voltage before and after boosting of the converter 53, a detection value of a rotary transformer (not shown) for detecting the rotational position of the rotor of the motor generators MG1 and MG2, a phase current applied to the motor generators MG1 and MG2, etc. The MGECU 55 controls the driving of the motor generators MG1 and MG2 by switching the first and second inverters 51 and 52 and the converter 53 based on these signals, etc. Furthermore, MGECU 55 calculates rotation speeds Nm1 and Nm2 of the rotors of motor generators MG1 and MG2 based on the detection values ​​of the resolvers.

[0034] HVECU60 includes a microcomputer including a CPU, ROM, RAM, input / output interfaces, etc., which are not shown in the figure, various drive circuits, various logic ICs, etc. HVECU60 exchanges information (communication frames) with engine ECU90, power management ECU45, MGECU55, etc. via a CAN bus including two communication lines (wiring harnesses) Lo and Hi, that is, a common communication line (multi-channel communication bus) not shown in the figure. In addition, HVECU60 is connected to engine ECU90, power management ECU45, MGECU55 via a CAN bus including two communication lines (wiring harnesses) Lo and Hi, that is, a dedicated communication line (local communication bus). HVECU60 exchanges information (communication frames) with engine ECU90, power management ECU45, MGECU55 via corresponding dedicated communication lines. Furthermore, the HVECU 60 obtains a signal from a start switch (not shown) for instructing the system start of the hybrid vehicle 1, a shift position SP of the shift lever 72 detected by the shift position sensor 71, an accelerator opening Acc (amount of depression of the accelerator pedal 74) detected by the accelerator pedal position sensor 73, a vehicle speed V detected by a vehicle speed sensor (not shown), a crankshaft position from a crank angle sensor 80 of the engine 10, etc. In addition, the HVECU 60 obtains the SOC (charging rate) of the power storage device 40, the allowable charging power Win, the allowable discharging power Wout from the power management ECU 45, and the rotation speeds Nm1 and Nm2 of the motor generators MG1 and MG2 from the MGECU 55, etc.

[0035] When the hybrid vehicle 1 is running, the HVECU 60 derives the required torque Tr* (including the required braking torque) to be output to the drive shaft DS corresponding to the accelerator opening Acc and the vehicle speed V from the required torque setting map (not shown). Moreover, the HVECU 60 sets the required running power Pd* (=Tr*×Nds) required for the running of the hybrid vehicle 1 based on the required torque Tr* and the rotation speed Nds of the drive shaft DS. In addition, the HVECU 60 determines whether to load the engine 10 based on the required torque Tr*, the required running power Pd*, the target charge and discharge power Pb* of the power storage device 40 set separately, the allowable discharge power Wout, etc.

[0036] When the engine 10 is operated under load, the HVECU 60 sets the required power Pe* (=Pd*-Pb*+Loss) for the engine 10 based on the required running power Pd*, the target charge and discharge power Pb*, etc. Moreover, the HVECU 60 sets the target speed Ne* of the engine 10 corresponding to the required power Pe* in such a way that the engine 10 operates efficiently and does not fall below the lower limit speed Nelim corresponding to the operating state of the hybrid vehicle 1, etc. Moreover, the HVECU 60 sets the torque instructions Tm1*, Tm2* for the motor generators MG1, MG2 corresponding to the required torque Tr*, the target speed Ne*, etc. within the range of the allowable charge power Win and the allowable discharge power Wout of the power storage device 40. On the other hand, when the operation of the engine 10 is stopped, the HVECU 60 sets the required power Pe*, the target speed Ne*, and the torque instruction Tm1* to zero. HVECU 60 then sets torque command Tm2* within the range of allowable charge power Win and allowable discharge power Wout of power storage device 40 so that torque corresponding to required torque Tr* is output from motor generator MG2 to drive shaft DS.

[0037] Then, HVECU60 sends the required power Pe* and the target speed Ne* to the engine ECU90, and sends the torque instructions Tm1* and Tm2* to the MGECU55. The engine ECU90 performs intake air amount control, fuel injection control, ignition timing control, etc. based on the required power Pe* and the target speed Ne*. In the present embodiment, the engine ECU90 basically performs fuel injection control in such a way that the air-fuel ratio in each cylinder 11 of the engine 10 becomes the theoretical air-fuel ratio (=14.6-14.7). In addition, in the present embodiment, the fuel injection and ignition to the plurality of cylinders 11 are performed in the order (ignition order) of cylinder #1 No. 1 → cylinder #3 No. 3 → cylinder #4 No. 4 → cylinder #2 No. 2.

[0038] In addition, MGECU55 performs switching control on the first and second converters 51, 52 and the converter 53 based on the torque instructions Tm1*, Tm2*. When the engine 10 is operated under load, the motor generators MG1, MG2 are controlled to convert a part of the power output from the engine 10 (when the power storage device 40 is charged) or all (when the power storage device 40 is discharged) of the power output from the engine 10 together with the planetary gear 30 into torque and output it to the drive shaft DS. As a result, the hybrid vehicle 1 runs by the power from the engine 10 and the power from the motor generator MG2. In contrast, when the operation of the engine 10 is stopped, the hybrid vehicle 1 runs only by the power from the motor generator MG2.

[0039] When a communication abnormality such as a delay or interruption occurs in the communication frame between the engine ECU90 and the HVECU55, the engine ECU90 performs a retreat driving operation without relying on the required power Pe* and the target speed Ne* sent from the HVECU55, and performs intake air volume control, fuel injection control, and ignition timing control based on the accelerator opening Acc and the vehicle speed V, and drives the hybrid vehicle 1 only by running the engine 10.

[0040] Here, as described above, the hybrid vehicle 1 of the present embodiment includes the downstream side purification device 19 having the particulate trap 190 as the exhaust purification device. The accumulation amount Dpm of the particulate matter in the particulate trap 190 increases as the travel distance of the hybrid vehicle 1 increases, and the lower the ambient temperature, the more it increases. Therefore, in the hybrid vehicle 1, in the stage where the accumulation amount Dpm of the particulate matter in the particulate trap 190 increases, it is necessary to send a lot of air, that is, oxygen, to the particulate trap 190 after the temperature is sufficiently raised to burn the particulate matter and regenerate the particulate trap 190. Therefore, in the hybrid vehicle 1, when the engine 10 is operated under load in response to the driver of the hybrid vehicle 1 stepping on the accelerator pedal 74, Figure 3 The illustrated routine for determining whether or not the particulate trap needs to be regenerated is executed by the engine ECU 90 at predetermined time intervals.

[0041] exist Figure 3At the start of the routine, the engine ECU 90 obtains information required for determination, such as the intake air amount GA, the rotation speed Ne, the cooling water temperature Tw, and the temperature Tpf of the particulate trap 190 of the engine 10 (step S100). Furthermore, the engine ECU 90 calculates the accumulation amount Dpm of the particulate matter in the particulate trap 190 by either the operation history method or the differential pressure method corresponding to the operation state of the engine 10, based on the physical quantities etc. obtained in step S100 (step S110). Next, the engine ECU 90 determines whether the partial cylinder fuel cut control routine for raising the temperature of the exhaust purification catalyst 180 of the upstream side purification device 18 and the particulate trap 190 of the downstream side purification device 19 is already being executed (step S120).

[0042] If it is determined that the partial cylinder fuel cutoff control routine is not executed (step S120: Yes), the engine ECU 90 determines whether the accumulation amount Dpm calculated in step S110 is greater than a predetermined threshold value D1 (e.g., a value of about 5000 mg) (step S130). If it is determined that the accumulation amount Dpm is less than the threshold value D1 (step S130: No), the engine ECU 90 performs the partial cylinder fuel cutoff control routine at that time. Figure 3 The routine is temporarily terminated. In addition, when it is determined that the accumulation amount Dpm is greater than the threshold value D1 (step S130: Yes), the engine ECU 90 determines whether the temperature Tpf of the particulate trap 190 obtained in step S100 is lower than a predetermined partial cylinder fuel cut-off control start temperature (predetermined temperature) Tx (step S140). The temperature increase control start temperature Tx is predetermined according to the use environment of the hybrid vehicle 1, and in the present embodiment, for example, is a temperature of about 600°C.

[0043] When it is determined that the temperature Tpf of the particulate trap 190 is equal to or higher than the partial cylinder fuel cut control start temperature Tx (step S140: No), the engine ECU 90 at that time causes the Figure 3 The routine is temporarily terminated. In addition, when it is determined that the temperature Tpf of the particulate trap 190 is lower than the partial cylinder fuel cut control start temperature Tx (step S140: Yes), the engine ECU 90 determines whether there is a communication abnormality such as delay or interruption in the communication frame between the engine ECU 90 and the HVECU 60 (step S150). For example, Figure 3 If no communication frames are exchanged between the engine ECU 90 and the HVECU 60 for a period longer than a predetermined time from the start of the routine, it is determined that there is a communication abnormality; if communication frames are exchanged between the ECUs for a period shorter than a predetermined time, it is determined that there is no communication abnormality.

[0044] If there is no communication abnormality (step S150: Yes), the partial cylinder fuel cut flag is set to active, and the partial cylinder fuel cut control routine is executed (step S160). Figure 3 The routine ends temporarily. If there is a communication abnormality (step S150: No), the engine ECU 90 compares the speed Ne with the partial cylinder fuel cut execution speed Nex (step S155). If the speed Ne is lower than the partial cylinder fuel cut execution speed Nex (step S155: Yes), the engine ECU 90 compares the speed Ne with the partial cylinder fuel cut execution speed Nex (step S155). Figure 3 In this case, the partial cylinder fuel cut control routine does not start. On the other hand, if the speed Ne is greater than the partial cylinder fuel cut execution speed Nex (step S155: No), the partial cylinder fuel cut flag is set to active, and the partial cylinder fuel cut control routine is executed (step S160), so that Figure 3 The routine ends temporarily. The partial cylinder fuel cut execution speed Nex is predetermined according to the resonance frequency region of the hybrid vehicle 1, and in the present embodiment, is, for example, about 2000 rpm.

[0045] On the other hand, when it is determined that the partial cylinder fuel cut-off control routine is already being executed (step S120: No), the engine ECU 90 determines whether the accumulation amount Dpm calculated in step S110 is less than a threshold value D0 (for example, a value of about 3000 mg) which is predetermined to be smaller than the above-mentioned threshold value D1 (step S170). When it is determined that the accumulation amount Dpm is less than the threshold value D0 (step S170: No), the engine ECU 90 sets the partial cylinder fuel cut-off flag to be inactive at that time point, terminates the partial cylinder fuel cut-off control routine (step S190), and makes Figure 3 The routine is temporarily terminated. In addition, when it is determined that the accumulation amount Dpm exceeds the threshold value D0 (step S170: Yes), the engine ECU 90 determines whether there is a communication abnormality such as a delay or interruption in the communication frame between the engine ECU 90 and the HVECU 60 (step S180). The method for determining the communication abnormality can be the same as that of step S150.

[0046] If there is no communication abnormality (step S180: Yes), Figure 3 The routine is temporarily terminated. If there is a communication abnormality (step S180: No), the engine ECU 90 compares the speed Ne with the partial cylinder fuel cut execution speed Nex (step S185). If the speed Ne is lower than the partial cylinder fuel cut execution speed Nex (step S185: Yes), the partial cylinder fuel cut flag is set to inactive, and the partial cylinder fuel cut control routine is terminated (step S190). Figure 3 The routine ends for now.

[0047] Next, a partial cylinder fuel cut control routine for raising the temperature of the exhaust purification catalyst 180 and the particulate trap 190 will be described. Figure 4 is exemplified in Figure 3 The flowchart of the partial cylinder fuel cutoff control routine executed by the engine ECU 90 at predetermined intervals when the partial cylinder fuel cutoff flag is set to active in the routine of FIG. The partial cylinder fuel cutoff control routine is executed while the engine 10 is under load operation due to the driver's depression of the accelerator pedal 74 until the partial cylinder fuel cutoff flag is set to inactive.

[0048] At the start of the partial cylinder fuel cut control routine, the engine ECU 90 obtains information necessary for control, such as the intake air volume GA, the speed Ne, the cooling water temperature Tw of the engine 10, the temperature Tpf of the particulate trap 190, the crankshaft position from the crank angle sensor 80, the required power Pe* and the target speed Ne* from the HVECU 60 (step S200). Figure 3 If there is a communication abnormality in step S150 and the speed Ne is greater than the partial cylinder fuel cut execution speed Nex in step S155, the information required for control such as the required power Pe* and the target speed Ne* from the HVECU60 is not obtained, and the accelerator opening Acc and the vehicle speed V are obtained.

[0049] After the processing of step S200, the engine ECU 90 sets the fuel injection control amount such as the fuel injection amount from each in-cylinder injection valve 15 and the fuel injection end timing (step S210). In step S210, the engine ECU 90 sets the fuel injection amount to zero for a part of the cylinders 11 (for example, cylinder #1) among the plurality of cylinders 11 of the engine 10. In addition, in step S210, the engine ECU 90 increases the fuel injection amount to the remaining cylinders 11 (for example, cylinder #2, cylinder #3, and cylinder #4) other than the part of the cylinders 11 by, for example, 20% to 25% (20% in the present embodiment) of the fuel injection amount that should be supplied to the one cylinder 11 (cylinder #1), thereby increasing (enriching) the amount of fuel relative to the air. Hereinafter, stop of fuel supply is appropriately referred to as “fuel cut (F / C)”, the cylinder 11 to which fuel supply is stopped is appropriately referred to as a “fuel cut cylinder”, and the cylinder 11 to which fuel supply is performed is appropriately referred to as a “combustion cylinder”.

[0050] After step S210, a fuel cut-off cylinder discrimination signal, which is a signal indicating the crankshaft position of the fuel cut-off cylinder in each cylinder, is sent to HVECU60 (step S220). After the fuel cut-off cylinder discrimination signal is sent to HVECU60 in step S220, the engine ECU90 discriminates the cylinder 11 for which the fuel injection start timing has arrived based on the crankshaft position from the crank angle sensor 80 (step S230). When the engine ECU90 determines that the fuel injection start timing of the above-mentioned fuel cut-off cylinder (cylinder No. 1 #1) has arrived through the discrimination process of step S230 (step S240: No), the fuel is not injected from the in-cylinder injection valve 15 corresponding to the cylinder 11, and it is determined whether a cycle of fuel injection that causes the engine 10 to rotate two circles has been completed (step S260). During the period when the fuel supply to the fuel cut cylinder (No. 1 cylinder #1) is stopped (during fuel cut), the intake valve and exhaust valve of the fuel cut cylinder are opened and closed in the same manner as when the fuel is supplied. In addition, when the engine ECU 90 determines through the determination process of step S230 that the fuel injection start timing of one of the combustion cylinders (No. 2 cylinder #2, No. 3 cylinder #3 and No. 4 cylinder #4) has arrived (step S240: Yes), the fuel is injected from the corresponding in-cylinder injection valve 15 to the combustion cylinder (step S250), and it is determined whether one cycle of fuel injection has been completed (step S260).

[0051] When it is determined that the fuel injection for one cycle is not completed (step S260: No), the engine ECU 90 repeatedly executes the processing of steps S230-S250. In addition, during the execution of this routine, the opening of the throttle valve 14 is set based on the required power Pe* and the target speed Ne* (required torque) or the accelerator opening Acc and the vehicle speed V. Therefore, through the processing of steps S230-S260, the fuel supply to the above-mentioned fuel cut cylinder (cylinder No. 1 #1) is stopped, and the air-fuel ratio in the above-mentioned combustion cylinders (cylinder No. 2 #2, cylinder No. 3 #3 and cylinder No. 4 #4) is enriched. When it is determined that the fuel injection for one cycle is completed (step S260: Yes), the engine ECU 90 executes the processing after step S200 again.

[0052] Figure 5 is exemplified in Figure 3 Flowchart of the driving force compensation control routine which is repeatedly executed by the HVECU 60 at predetermined intervals in parallel with the above-mentioned partial cylinder fuel cut-off control routine after the engine ECU 90 sets the partial cylinder fuel cut-off flag to active in step S160. It should be noted that in the case where the communication frame between the engine ECU 90 and the HVECU 60 is interrupted, Figure 3In step S155, when the speed Ne is greater than the partial cylinder fuel cut execution speed Nex, the driving force compensation control routine is not started because the HVECU 60 cannot obtain information related to the partial cylinder fuel cut flag.

[0053] At the beginning of the driving force compensation control routine, HVECU60 obtains information required for control such as accelerator opening Acc, vehicle speed V, crankshaft position from crankshaft angle sensor 80, rotation speed Nm1, Nm2 of motor generators MG1, MG2, SOC of storage device 40, target charge and discharge power Pb*, allowable charge power Win and allowable discharge power Wout, and fuel cut-off cylinder judgment signal (crankshaft position) from engine ECU90 (step S300).

[0054] After the processing of step S300, it is determined whether there is a communication abnormality such as delay or interruption in the communication frames between the engine CU90, HVECU60, MGECU55, and power management ECU45 (specifically, between each combination of the engine ECU90 and HVECU60, HVECU60 and MGECU55, and HVECU60 and power management ECU45) (step S310). For example, it is determined that there is a communication abnormality if there is no exchange of communication frames between the ECUs for a period of more than a predetermined time since the start of the driving force compensation control routine, and it is determined that there is no communication abnormality if there is an exchange of communication frames between the ECUs for a period of less than a predetermined time.

[0055] In the case of a communication anomaly (step S310: No), HVECU60 compares the target speed Ne* with the partial cylinder fuel cut-off execution speed Nex (step S355). In the case where the target speed Ne* is smaller than the partial cylinder fuel cut-off execution speed Nex (step S355: Yes), HVECU60 sends a fuel cut-off prohibition signal to the engine ECU90 (step S360) in such a way that the engine ECU90 sets the partial cylinder fuel cut-off flag to inactive, thereby temporarily terminating the driving force compensation control routine. In this case, the execution of the partial cylinder fuel cut-off control routine by the engine ECU90 is suspended or stopped. On the other hand, in the case where the target speed Ne* is larger than the partial cylinder fuel cut-off execution speed Nex (step S355: No), the driving force compensation control routine is temporarily terminated. The partial cylinder fuel cut-off execution speed Nex is predetermined according to the resonance frequency region of the hybrid vehicle 1, and in the present embodiment, for example, is a speed of about 2000 rpm.

[0056] When there is no communication abnormality (step S310: Yes), HVECU60 sets the required torque Tr* based on the accelerator opening Acc and the vehicle speed V, and sets the required power Pe* relative to the engine 10 based on the required torque Tr* (required running power Pd*), the target charge and discharge power Pb* of the power storage device 40, etc. (step S320).

[0057] After the processing of step S320, HVECU60 derives the rotation speed corresponding to the required power Pe* for efficiently operating the engine 10 from a map (not shown), and sets the larger one of the derived rotation speed and the lower limit value of the rotation speed of the engine 10, i.e., the lower limit rotation speed Nelim, as the target rotation speed Ne* of the engine 10 (step S330). In addition, in step S330, HVECU60 sets the value obtained by dividing the required power Pe* by the target rotation speed Ne* as the target torque Te* of the engine 10. Moreover, HVECU60 sets the torque command Tm1* for the motor generator MG1 corresponding to the target torque Te* and the target rotation speed Ne* and the torque command Tm2* for the motor generator MG2 corresponding to the required torque Tr* and the torque command Tm1* within the range of the allowable charging power Win and the allowable discharging power Wout of the power storage device 40 (step S340).

[0058] Next, it is determined whether the execution of the partial cylinder fuel cut-off control routine, that is, the execution of the fuel cut-off of a part of the cylinders 11 is allowed (step S350). In step S350, the HVECU 60 calculates the insufficient driving torque due to the fuel cut-off of one cylinder 11, that is, the torque that is no longer output from the engine 10 due to the fuel cut-off (hereinafter, appropriately referred to as "insufficient torque"). In more detail, the HVECU 60 multiplies the value obtained by dividing the required torque Tr* set in step S320 by the number of cylinders n of the engine 10 (in this embodiment, n=4) by the gear ratio G between the rotor of the motor generator MG2 and the drive shaft DS to calculate the insufficient torque (=Tr*·G / n). Moreover, in step S350, the HVECU 60 determines whether the insufficient torque can be compensated by the motor generator MG2 based on the insufficient torque, the torque instructions Tm1*, Tm2* set in step S340, the allowable charging power Win and the allowable discharge power Wout of the storage device 40.

[0059] In the determination process of step S350, if it is determined that the insufficient driving torque due to the fuel cutoff of some cylinders 11 cannot be compensated by the motor generator MG2 (step S350: No), the HVECU 60 advances the process to the above-mentioned step S355. In addition, if it is determined that the insufficient driving torque due to the fuel cutoff of some cylinders 11 can be compensated by the motor generator MG2 (step S350: Yes), the fuel cutoff is permitted, and the HVECU 60 sends the required power Pe* set in step S320 and the target speed Ne* set in step S330 to the engine ECU 90 (step S370).

[0060] After sending the required power Pe* and the target speed Ne* to the engine ECU 90, the HVECU 60 determines the cylinder 11 whose fuel injection start timing arrives next based on the crankshaft position from the crankshaft angle sensor 80 and the fuel cut cylinder discrimination signal (crankshaft position) received from the engine ECU 90 in step S300 (step S390). When the HVECU 60 determines that the fuel injection start timing of one of the combustion cylinders (cylinder #2, cylinder #3 or cylinder #4) arrives through the determination process of step S390 (step S390: Yes), the torque instructions Tm1* and Tm2* set in step S340 are sent to the MGECU 55 (step S400), and the driving force compensation control routine is temporarily terminated. When HVECU 60 determines in the determination process of step S390 that the fuel injection start timing of the fuel cut cylinder (number 1 cylinder # 1 ) has arrived (step S390 : NO), it resets torque command Tm2 * to motor generator MG2 (step S395 ).

[0061] In step S395, HVECU 60 sets the sum of the torque command Tm2* set in step S340 and the above-mentioned insufficient torque (=Tr*·G / n) as a new torque command Tm2*. After the processing of step S395, HVECU 60 sends the torque command Tm1* set in step S340 and the torque command Tm2* set again in step S395 to MGECU 55 (step S400), so that the driving force compensation control routine is temporarily terminated. Thus, during the period when the fuel supply to the fuel cut cylinder of the engine 10 is stopped (during fuel cut), the motor generator MG1 is controlled by MGECU 55 in a manner that rotates the engine 10 at the target speed Ne*, and the motor generator MG2 is controlled by MGECU 55 in a manner that compensates for the above-mentioned insufficient torque.

[0062] Execute the above Figure 3 to Figure 5As a result of the routine shown, in the hybrid vehicle 1, when the accumulation amount Dpm of particulate matter in the particulate trap 190 of the downstream side purification device 19 becomes equal to or greater than the threshold value D1, in order to increase the temperature of the exhaust purification catalyst 180 of the upstream side purification device 18 and the particulate trap 190 of the downstream side purification device 19, the fuel supply to at least one cylinder 11 of the engine 10 is stopped during the period when the engine 10 is operated under load in response to the driver's depression of the accelerator pedal 74, and the fuel supply to the remaining cylinders 11 is performed. In addition, during the execution of the fuel cut, the motor generator MG2 as the power generation device is controlled in such a manner as to compensate for the torque (driving force) that is insufficient due to the stop of the fuel supply to at least one cylinder 11.

[0063] During the execution of the partial cylinder fuel cutoff control routine and the driving force compensation control routine, the partial cylinder fuel cutoff flag, the fuel cutoff cylinder discrimination signal, the required power Pe*, and the target speed Ne* are transmitted through communication between the engine ECU 90 and the HVECU 60, the torque instructions Tm1* and Tm2* are transmitted through communication between the HVECU 60 and the MGECU 55, and the allowable charging power Win and the allowable discharging power Wout are transmitted through communication between the HVECU 60 and the power management ECU 45. In order to determine whether there is a possibility of abnormality in the transmission and reception of the partial cylinder fuel cutoff flag and the fuel cutoff cylinder discrimination signal between the engine ECU 90 and the HVECU 60, Figure 3In the routine, before the transmission and reception of the partial cylinder fuel cut flag and the fuel cut cylinder discrimination signal, it is determined whether there is a communication abnormality such as a delay or interruption in the communication frame between the engine ECU90 and the HVECU60. If there is a communication abnormality between the engine ECU90 and the HVECU60 at this timing, it can be considered that even if the partial cylinder fuel cut flag and the fuel cut cylinder discrimination signal are transmitted and received, there will be a delay or interruption. Therefore, by prohibiting the partial cylinder fuel cut control, the driving force reduction caused by the fuel cut and the timing deviation of the fuel cut and the timing of compensating for the insufficient torque due to the fuel cut can be suppressed, and the driving force fluctuation caused by the asynchronous driving force compensation based on the motor generator MG2 can be suppressed. In addition, in order to determine whether there is a possibility of abnormalities in the transmission and reception of torque instructions Tm1*, Tm2* between HVECU60 and MGECU55, or in the values ​​of torque instructions Tm1*, Tm2* themselves, in the driving force compensation control routine, before the transmission and reception of torque instructions Tm1*, Tm2* between HVECU60 and MGECU55, it is determined whether there are communication abnormalities such as delays or interruptions in the communication frames between HVECU60 and MGECU55 and between HVECU60 and the power management ECU45. If there is a communication anomaly between HVECU60 and MGECU55 under this timing, it can be considered that even the sending and receiving of torque instructions Tm1*, Tm2* will cause delays and interruptions. In addition, if there is a communication anomaly between HVECU60 and the power management ECU45, there is a possibility that the values ​​of torque instructions Tm1*, Tm2* themselves will become inappropriate values. Therefore, by prohibiting some cylinder fuel cut-off control, it is possible to suppress the driving force reduction caused by fuel cut-off due to the timing deviation of fuel cut-off and the timing deviation of compensating for the insufficient torque due to fuel cut-off and the driving force fluctuation caused by the asynchronous driving force compensation based on the electric generator MG2.

[0064] In addition, even in the case of communication anomalies such as delays or interruptions in the communication frames between the ECUs, when the speed Ne or the target speed Ne* of the engine 10 is greater than the partial cylinder fuel cut execution speed Nex, the driving force compensation control is not executed and the fuel cut is allowed. Since the driving force compensation control is not executed, the driving force changes, but when the speed Ne or the target speed Ne* of the engine 10 is greater than the partial cylinder fuel cut execution speed Nex, the driving force change itself is smaller than when it is less than the partial cylinder fuel cut execution speed Nex. Therefore, when the speed Ne or the target speed Ne* of the engine 10 is greater than the partial cylinder fuel cut execution speed Nex, the fuel cut is allowed without executing the driving force compensation control, and the regeneration of the particulate filter 190 is given priority over the suppression of the driving force change.

[0065] The correspondence between the matters in the above-mentioned embodiment and the matters described in the claims is as follows. The first electronic control unit corresponds to the engine ECU 90. The second electronic control unit corresponds to the HVECU 60. The partial cylinder fuel cut-off control corresponds to the partial cylinder fuel cut-off control routine. The control information of the partial cylinder fuel cut-off control corresponds to the partial cylinder fuel cut-off flag and the fuel cut-off cylinder discrimination signal. The driving force compensation control corresponds to the driving force compensation control routine. The third electronic control unit corresponds to the MGECU 55. The command value corresponds to the torque command Tm1*, Tm2* set in step S340.

[0066] It should be noted that, in the above-mentioned embodiment, HVECU 60 and MGECU 55 are set as independent ECUs, but HVECU 60 may also serve as MGECU 55. In this case, HVECU 60 sets torque instructions Tm1*, Tm2* for motor generators MG1, MG2 corresponding to required torque Tr*, target speed Ne*, etc. within the range of permissible charge power Win and permissible discharge power Wout of power storage device 40, and performs switching control on first and second inverters 51, 52 and converter 53 based on the set torque instructions Tm1*, Tm2*.

[0067] In addition, in the above-mentioned embodiment, if the execution of the partial cylinder fuel cut-off control routine is allowed, the air-fuel ratio in all combustion cylinders other than the fuel cut-off cylinder is enriched, but it is not limited to this. That is, in the above-mentioned hybrid vehicle 1, instead of enriching the air-fuel ratio in the combustion cylinder at the beginning of the partial cylinder fuel cut-off control routine, the air-fuel ratio in the combustion cylinder can be set to the theoretical air-fuel ratio. In this scheme, compared with the case where the air-fuel ratio in the combustion cylinder is enriched, it takes time to heat up the upstream and downstream purification devices 18 and 19, but it is possible to make the unburned fuel react in the presence of sufficient oxygen, and the temperature of the upstream and downstream purification devices 18 and 19 is sufficiently increased by the reaction heat. In addition, by continuously stopping the fuel supply to a part of the cylinders 11, a sufficient amount of oxygen can be supplied to the interior of the upstream and downstream purification devices 18 and 19 after the temperature is increased.

[0068] In addition, in the above-mentioned embodiment, the partial cylinder fuel cut control is executed in order to regenerate the particulate trap 190, but the present invention is not limited to this. For example, when the downstream air-fuel ratio sensor 86 detects a rich air-fuel ratio, the partial cylinder fuel cut control may be executed in order to rapidly increase oxygen in the exhaust purification catalyst 180. In this case, instead of setting the execution condition of the partial cylinder fuel cut control as that the accumulation amount Dpm is greater than the threshold value D1 and the temperature Tpf of the particulate trap 190 is less than the partial cylinder fuel cut control start temperature Tx, for example, the execution condition of the partial cylinder fuel cut control may be that the downstream air-fuel ratio AFr is less than the threshold value AF1.

[0069] In addition, the engine 10 of the hybrid vehicle 1 is an in-line engine, and the partial cylinder fuel cut-off control routine is constructed in a manner that stops the fuel supply to at least one cylinder 11 in one cycle, but is not limited to this. That is, the engine 10 of the hybrid vehicle 1 can also be a V-type engine, a horizontally opposed engine, or a W-type engine in which an exhaust gas purification device is provided for each cylinder bank. In this case, the partial cylinder fuel cut-off control routine is preferably constructed in a manner that the fuel supply to at least one cylinder in each cylinder bank is stopped in one cycle. As a result, sufficient oxygen can be supplied to the exhaust gas purification device of each cylinder bank of the V-type engine, etc.

[0070] Furthermore, the downstream purification device 19 may also include an exhaust purification catalyst (three-way catalyst) disposed on the upstream side and a particulate trap disposed on the downstream side of the exhaust purification catalyst. In this case, the upstream purification device 18 may also be omitted from the hybrid vehicle 1. In addition, the downstream purification device 19 may also include only a particulate trap. In this case, by utilizing the execution of the partial cylinder fuel cut-off control routine to heat up the exhaust purification catalyst of the upstream purification device 18, the high-temperature exhaust gas flowing in from the upstream purification device 18 can be utilized to heat up the downstream purification device 19 (particulate trap 190).

[0071] In the above embodiment, the hybrid vehicle 1 is a dual-motor hybrid vehicle in which the motor generator MG2 and the engine 10 are connected to the drive shaft DS, wherein the engine 10 is connected to the motor generator MG1 via the planetary gear 30, but it may be a single-motor hybrid vehicle in which the planetary gear 30, the motor generator MG1, and the first inverter 51 are omitted. In this case, the HVECU 60 sets the target speed Ne* of the engine 10 corresponding to the required power Pe*, and sets the torque command Tm2* for the motor generator MG2 corresponding to the required torque Tr*, the target speed Ne*, etc. within the range of the allowable charge power Win and the allowable discharge power Wout of the power storage device 40.

[0072] In the hybrid vehicle 1, the sun gear 31 of the planetary gear 30 may be connected to the motor generator MG1, the ring gear 32 may be connected to the output member, and the planetary gear 34 may be connected to the engine 10 and the motor generator MG2. Furthermore, the ring gear 32 of the planetary gear 30 may be connected to a step-type transmission. In the hybrid vehicle 1, the planetary gear 30 may be replaced by a four-element compound planetary gear mechanism including two planetary gears. In this case, the engine 10 may be connected to the input element of the compound planetary gear mechanism, the output member may be connected to the output element, the motor generator MG1 may be connected to one of the remaining two rotating elements, and the motor generator MG2 may be connected to the other. Furthermore, a clutch that connects two of the four rotating elements or a brake that can fix one of the four rotating elements in a non-rotatable manner may be provided in the compound planetary gear mechanism. In addition, the hybrid vehicle 1 may be configured as a plug-in hybrid vehicle in which the power storage device 40 can be charged with power from an external power source such as a household power source or a quick charger installed at a charging station.

[0073] In addition, in the above-mentioned embodiment, the hybrid vehicle 1 is driven in retreat mode, and the engine ECU 90 performs intake air amount control, fuel injection control, and ignition timing control based on the accelerator opening Acc and the vehicle speed V without relying on the required power Pe* and the target speed Ne* sent from the HVECU 55, and drives the hybrid vehicle 1 only by the operation of the engine 10. However, it is also possible that the engine ECU 90 stops the operation of the engine 10, and the HVECU 60 sets the torque command Tm2* within the range of the allowable charging power Win and the allowable discharge power Wout of the storage device 40 in such a way that a torque corresponding to the required torque Tr* is output from the motor generator MG2 to the drive shaft DS, thereby driving the hybrid vehicle 1.

[0074] About Electronic Control Units

[0075] The electronic control units 55, 60, and 90 are not limited to those having a CPU and a ROM and executing software processing. For example, they may also be provided with a dedicated hardware circuit such as an ASIC that performs hardware processing on at least a portion of the software processing performed in the above-mentioned embodiment. That is, the electronic control units 55, 60, and 90 may be any of the following structures (a) to (c). (a) It may be provided with a processing device that executes all of the above-mentioned processing according to a program and a program storage device such as a ROM that stores the program. (b) It may be provided with a processing device that executes a portion of the above-mentioned processing according to a program, a program storage device, and a dedicated hardware circuit that executes the remaining processing. (c) It may be provided with a dedicated hardware circuit that executes all of the above-mentioned processing. Here, the software execution device and the dedicated hardware circuit that have the processing device and the program storage device may also be multiple.

[0076] Furthermore, the invention disclosed herein is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the disclosure. Furthermore, the above-mentioned embodiments are only a specific form of the invention described in the Summary of the Invention column, and do not limit the elements of the invention described in the Summary of the Invention column.

Claims

1. A control device for a hybrid vehicle, The hybrid vehicle comprises: A multi-cylinder internal combustion engine having a catalyst in the exhaust system for purifying exhaust gas; and Electric motor, The hybrid vehicle is configured to transmit driving force from the multi-cylinder internal combustion engine and the electric motor to drive wheels. The control device comprises a first electronic control unit and a second electronic control unit, The first electronic control unit is configured to execute partial cylinder fuel cut-off control for stopping fuel supply to at least one cylinder and supplying fuel to remaining cylinders except the at least one cylinder, and to send control information of the partial cylinder fuel cut-off control to the second electronic control unit, The second electronic control unit is configured to execute a driving force compensation control of the electric motor based on the received control information of the partial cylinder fuel cut-off control, so as to compensate for a decrease in driving force of the multi-cylinder internal combustion engine caused by execution of the partial cylinder fuel cut-off control using the driving force of the electric motor. The first electronic control unit is further configured to prohibit execution of the partial cylinder fuel cutoff control when there is a possibility that an abnormality may occur in the transmission and reception of control information of the partial cylinder fuel cutoff control between the first electronic control unit and the second electronic control unit. The first electronic control unit is further configured to allow the partial cylinder fuel cut-off control to be executed when the speed of the multi-cylinder internal combustion engine is above a predetermined speed even when there is a possibility of abnormality in the transmission and reception of control information of the partial cylinder fuel cut-off control between the first electronic control unit and the second electronic control unit.

2. The control device for a hybrid vehicle according to claim 1, wherein: The control device of the hybrid vehicle further includes a third electronic control unit, The second electronic control unit is configured to calculate a command value for compensating for a reduction in the driving force of the multi-cylinder internal combustion engine by using the driving force of the electric motor based on the received control information of the partial cylinder fuel cut control, and send the command value to the third electronic control unit. The third electronic control unit is configured to drive and control the electric motor according to the received command value. The first electronic control unit is further configured to prohibit execution of the partial cylinder fuel cutoff control when there is a possibility that an abnormality may occur in the transmission and reception of the command value between the second electronic control unit and the third electronic control unit.

3. A control method for a hybrid vehicle, The hybrid vehicle comprises: A multi-cylinder internal combustion engine has a catalyst in the exhaust system for purifying exhaust gas; Electric motor; a first electronic control unit; and The second electronic control unit, The hybrid vehicle is configured to transmit driving force from the multi-cylinder internal combustion engine and the electric motor to drive wheels. The control method comprises the following steps: Using the first electronic control unit, executing partial cylinder fuel cut-off control of stopping fuel supply to at least one cylinder and supplying fuel to remaining cylinders except the at least one cylinder, and sending control information of the partial cylinder fuel cut-off control to the second electronic control unit; Using the second electronic control unit, executing a driving force compensation control for controlling the electric motor based on the received control information of the partial cylinder fuel cut-off control, so as to compensate for a decrease in driving force of the multi-cylinder internal combustion engine caused by the execution of the partial cylinder fuel cut-off control using the driving force of the electric motor; and prohibiting the first electronic control unit from executing the partial cylinder fuel cut-off control when there is a possibility of abnormality in the transmission and reception of control information of the partial cylinder fuel cut-off control between the first electronic control unit and the second electronic control unit, Even in the case where there is a possibility of abnormality in the transmission and reception of control information of the partial cylinder fuel cut-off control between the first electronic control unit and the second electronic control unit, the first electronic control unit is allowed to execute the partial cylinder fuel cut-off control when the speed of the multi-cylinder internal combustion engine is above a predetermined speed.

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