Control device for a hybrid vehicle

Abstract

To suppress the vehicle body vibration due to combustion stop of a partial cylinder.SOLUTION: A control device executes first damping processing of generating damping torque in a first rotary electric machine M1 during execution of combustion stop processing of continuing combustion of remaining cylinders 11 in such a state that combustion of a partial cylinder in the plurality of cylinders 11 provided in an engine 10 is stopped, and second damping processing of generating the damping torque in a second rotary electric machine M2. Then, the control device executes adjustment processing of making the amplitude of the damping torque generated in the first damping processing small and making the amplitude of the damping torque generated in the second damping processing large when the engine rotational speed is high, and making the amplitude of the damping torque generated in the first damping processing large and making the amplitude of the damping torque generated in the second damping processing small when the engine rotational speed is low.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] As a control device for a hybrid vehicle, the device described in Patent Document 1 is known. The hybrid vehicle controlled by the control device includes an engine having a plurality of cylinders, a first rotating electric machine, a second rotating electric machine, and a power split mechanism. Further, in the hybrid vehicle, the engine and the first rotating electric machine are drivingly connected to the drive shaft of the wheels via the power split mechanism, and the second rotating electric machine is drivingly connected to the drive shaft of the wheels without passing through the power split mechanism.

[0003] The control device of Patent Document 1 applied to such a hybrid vehicle performs a combustion stop process of continuing the combustion of the remaining cylinders while stopping the combustion of some of the plurality of cylinders, thereby raising the temperature of the catalyst device and the filter device for exhaust purification. When the combustion stop process is performed, the torque fluctuation of the engine increases and the vehicle body vibration increases. In contrast, the control device suppresses an increase in vehicle body vibration associated with the combustion stop process by compensating for the torque reduction associated with the combustion stop of some cylinders with the second rotating electric machine.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, there is a possibility that the vehicle body vibration cannot be sufficiently suppressed only by compensating for the torque reduction with the second rotating electric machine.

Means for Solving the Problems

[0006] A control device for a hybrid vehicle that solves the above problems is a control device for a hybrid vehicle having an engine with a plurality of cylinders, a first rotating electric machine, a second rotating electric machine, a power split mechanism, and an in-vehicle battery electrically connected to the first rotating electric machine and the second rotating electric machine. The engine and the first rotating electric machine are drivingly connected to the drive shaft of the wheels via the power split mechanism, and the second rotating electric machine is connected to the drive shaft of the wheels without passing through the power split mechanism. The control device performs a combustion stop process of continuing the combustion of the remaining cylinders while stopping the combustion of some of the plurality of cylinders, a first vibration damping process of generating vibration damping torque in the first rotating electric machine to suppress vehicle body vibration accompanying the execution of the combustion stop process, a second vibration damping process of generating vibration damping torque in the second rotating electric machine to suppress vehicle body vibration accompanying the execution of the combustion stop process, and an adjustment process of adjusting to increase the amplitude of the vibration damping torque generated in the second vibration damping process when the engine rotational speed is high, while adjusting to increase the amplitude of the vibration damping torque generated in the first vibration damping process when the engine rotational speed is low.

[0007] When the combustion stop process is performed, the torque fluctuation of the engine increases. Then, the vibration caused by the torque fluctuation of the engine is transmitted to the vehicle body, leading to an increase in vehicle body vibration. The vibration transmission path to the vehicle body includes a path from the engine through its mount to the vehicle body and a path from the engine through the power split mechanism and the drive shaft of the wheels to the vehicle body. Among these, the vibration transmission through the path via the engine mount is effectively suppressed by the first vibration damping process. Also, the vibration transmission through the path via the drive shaft of the wheels is effectively suppressed by the second vibration damping process. Note that the vehicle body vibration suppression effect by the first vibration damping process and the second vibration damping process can be enhanced by increasing the amplitude of the vibration damping torque generated respectively.

[0008] When the engine rotational speed is low, the intensity of the vibration transmitted to the vehicle body through the path via the mount is greater than the intensity of the vibration transmitted to the vehicle body through the path via the drive shaft. At this time, if the amplitude of the vibration damping torque in the first vibration damping process is increased, the effect of suppressing the vehicle body vibration is significantly improved. On the other hand, when the engine rotational speed is high, the intensity of the vibration transmitted to the vehicle body through the path via the drive shaft is greater than the intensity of the vibration transmitted to the vehicle body through the path via the mount. At this time, if the amplitude of the vibration damping torque in the second vibration damping process is increased, the effect of suppressing the vehicle body vibration is significantly improved. Therefore, the control device of the hybrid vehicle has a high effect of suppressing the vehicle body vibration caused by the combustion stop process.

[0009] The first vibration damping process in the control device of the hybrid vehicle may be configured as a process of generating a vibration damping torque so that the torque of the first rotating electric machine decreases at the same period as the period of the torque decrease of the engine due to the combustion stop of some cylinders. In this case, the generation of the vibration damping torque in the first vibration damping process is accompanied by an increase in the charging current of the in-vehicle battery.

[0010] The adjustment process in the case where the first vibration damping process is configured as described above may be configured to make the amplitude of the vibration damping torque generated in the first vibration damping process smaller when the charge rate of the in-vehicle battery is high than when it is low. In such a case, overcharging of the in-vehicle battery can be avoided. Further, the adjustment process in such a case may be configured to make the amplitude of the vibration damping torque generated in the second vibration damping process larger when the charge rate of the in-vehicle battery is high than when it is low.

[0011] When configuring the adjustment process in the case of the first vibration damping process as described above, when the temperature of the in-vehicle battery is low, it is preferable to configure the amplitude of the vibration damping torque generated in the first vibration damping process to be smaller than when the temperature is high. When the temperature of the in-vehicle battery is low, the charge and discharge capacity of the in-vehicle battery decreases. The generation of the vibration damping torque in the first vibration damping process is more likely to be restricted by the decrease in the charge and discharge capacity than the generation of the vibration damping torque in the second vibration damping process. Therefore, when the temperature of the in-vehicle battery is low, it is desirable to reduce the amplitude of the vibration damping torque generated in the first vibration damping process. Furthermore, the adjustment process in such a case is preferably configured such that when the temperature of the in-vehicle battery is low, the amplitude of the vibration damping torque generated in the second vibration damping process is larger than when the temperature is high.

[0012] When configuring the adjustment process in the case of the first vibration damping process as described above, when the charging of the in-vehicle battery continues for a predetermined time or more, it is preferable to configure the amplitude of the vibration damping torque generated in the second vibration damping process to be larger than when the charging of the in-vehicle battery does not continue for a predetermined time or more. When charging continues for a longer time than a certain level, the charge capacity of the in-vehicle battery decreases. When the charge capacity of the in-vehicle battery decreases, the generation of the vibration damping torque in the first vibration damping process may be restricted. On the other hand, even when the charge capacity of the in-vehicle battery decreases, the generation of the vibration damping torque in the second vibration damping process is less likely to be restricted. Therefore, as described above, even when the charge capacity of the in-vehicle battery decreases due to the continuation of charging, the suppression effect of vehicle body vibration is less likely to decrease.

[0013] When configuring the adjustment process in the case of the first vibration damping process as described above, when the discharging of the in-vehicle battery continues for a predetermined time or more, it is preferable to configure the amplitude of the vibration damping torque generated in the first vibration damping process to be larger than when the discharging of the in-vehicle battery does not continue for a predetermined time or more. When discharging continues for a longer time than a certain level, the discharge capacity of the in-vehicle battery decreases. When the discharge capacity of the in-vehicle battery decreases, the generation of the vibration damping torque in the first vibration damping process may be restricted. On the other hand, even when the discharge capacity of the in-vehicle battery decreases, the generation of the vibration damping torque in the second vibration damping process is less likely to be restricted. Therefore, as described above, even when the discharge capacity of the in-vehicle battery decreases due to the continuation of discharging, the suppression effect of vehicle body vibration is less likely to decrease.

[0014] When configuring the first vibration damping process as described above, the adjustment process may be configured such that when the integrated current of the in-vehicle battery is large, the amplitude of the vibration damping torque generated in the first vibration damping process is adjusted to increase, and the amplitude of the vibration damping torque generated in the second vibration damping process is adjusted to decrease. In such a case, due to the increase in the integrated current value, it is possible to effectively suppress the vehicle body vibration while suppressing further temperature rise of the electrical circuit components in a state where the electrical circuit components are at a high temperature.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0016] Hereinafter, an embodiment of a control device for a hybrid vehicle will be described in detail with reference to FIGS. 1 to 7. <Configuration of the Drive System of the Hybrid Vehicle> First, with reference to FIG. 1, the configuration of the drive system of the hybrid vehicle controlled by the control device 30 of the present embodiment will be described. As shown in FIG. 1, the hybrid vehicle includes an engine 10, a first rotating electric machine M1, and a second rotating electric machine M2. The engine 10 is a heat engine that burns fuel to generate power. The engine 10 is suspended from the vehicle body B via an engine mount 10B. The first rotating electric machine M1 and the second rotating electric machine M2 have functions as an electric motor that receives electric power to generate power and as a generator that receives power from the outside to generate electricity.

[0017] The engine 10 includes a plurality of cylinders 11 that perform combustion, an intake passage 12 that is an intake introduction passage to each cylinder 11, and an exhaust passage 13 that is an exhaust discharge passage from each cylinder 11. The engine 10 also includes a crankshaft 10A that serves as a power take-out shaft. A throttle valve 14 for adjusting the intake air amount of each cylinder 11 is installed in the intake passage 12. A catalyst device 15A carrying a three-way catalyst is installed in the exhaust passage 13. A filter device 15B that collects PM (Particulate Matter) in the exhaust is installed in a portion of the exhaust passage 13 downstream of the catalyst device 15A. Further, an injector 16 that injects fuel into the intake air introduced into each cylinder 11 is installed for each cylinder in the engine 10. An ignition device 17 is installed in each cylinder 11 of the engine 10. The ignition device 17 ignites the air-fuel mixture of the intake air introduced through the intake passage 12 and the fuel injected by the injector 16 by spark discharge. The combustion energy of the air-fuel mixture in each cylinder 11 is converted into the rotational energy of the crankshaft 10A.

[0018] Further, the hybrid vehicle is provided with a power split mechanism 20. The power split mechanism 20 has a planetary gear composed of three rotating elements: a sun gear S, a planetary carrier C, and a ring gear R. The crankshaft 10A of the engine 10 is connected to the planetary carrier C via a flywheel 18 and a torsional damper 19. The first rotating electric machine M1 is connected to the sun gear S. And the drive shaft 23 of the wheel 24 is connected to the ring gear R via a speed reduction mechanism 21 and a differential mechanism 22. The second rotating electric machine M2 is connected to the speed reduction mechanism 21. In such a hybrid vehicle, the engine 10 and the first rotating electric machine M1 are respectively drivingly connected to the drive shaft 23 of the wheel 24 via the power split mechanism 20, and the second rotating electric machine M2 is drivingly connected to the drive shaft 23 of the wheel 24 without passing through the power split mechanism 20.

[0019] On the other hand, the first rotating electric machine M1 is electrically connected to the in-vehicle battery 27 via the first inverter 25. Also, the second rotating electric machine M2 is connected to the in-vehicle battery 27 via the second inverter 26. Both the first inverter 25 and the second inverter 26 are power conversion circuits that convert the terminal voltage of the in-vehicle battery 27, which is a DC voltage source, into an AC voltage and output it.

[0020] <Configuration of the control device 30> Subsequently, with reference to FIG. 2, the configuration of the control device 30 that controls the hybrid vehicle will be described. The control device 30 performs torque control of each of the engine 10, the first rotating electric machine M1, and the second rotating electric machine M2. The control device 30 operates the throttle valve 14, the injector 16, and the ignition device 17 installed in the engine 10 in order to control the torque of the engine 10. Also, the control device 30 operates the first inverter 25 in order to control the torque of the first rotating electric machine M1. Further, the control device 30 operates the second inverter 26 in order to control the torque of the second rotating electric machine M2.

[0021] The control device 30 receives detection signals from an air flow meter 33, a crank angle sensor 34, and a water temperature sensor 35 installed in the engine 10. The air flow meter 33 is a sensor that detects the intake air flow rate GA in the intake passage 12 of the engine 10. The crank angle sensor 34 is a sensor that detects the crank angle, which is the rotation angle of the crankshaft 10A. The water temperature sensor 35 is a sensor that detects the engine water temperature THW, which is the temperature of the engine cooling water. Further, the control device 30 also receives detection signals from an output rotation speed sensor 36, an accelerator pedal sensor 37, and a battery temperature sensor 38. The output rotation speed sensor 36 is a sensor that detects the output rotation speed NP, which is the rotation speed of the ring gear R. The accelerator pedal sensor 37 is a sensor that detects the accelerator pedal operation amount ACC, which is the operation amount of the accelerator pedal by the occupant of the hybrid vehicle. The battery temperature sensor 38 is a sensor that detects the battery temperature THB, which is the temperature of the in-vehicle battery 27.

[0022] The control device 30 includes a CPU 31 and a ROM 32. The control device 30 controls the torques of the engine 10, the first rotating electric machine M1, and the second rotating electric machine M2 by the CPU 31 executing the programs stored in the ROM 32.

[0023] <Adjustment of Driving Force of Hybrid Vehicle> Next, the process executed by the CPU 31 to adjust the driving force of the hybrid vehicle will be described. Note that the process described here is the process during normal operation of the engine 10 when the combustion stop process described later is not being performed.

[0024] When adjusting the driving force, the CPU 31 first calculates a required driving torque TD* based on the accelerator pedal operation amount ACC and the output rotation speed NP. Further, the CPU 31 calculates a required driving force PD* based on the required driving torque TD* and the output rotation speed NP. The required driving torque TD* is the required value of the driving torque of the hybrid vehicle. Also, the required driving force PD* is the required value of the driving force of the hybrid vehicle.

[0025] Subsequently, the CPU 31 calculates the charging / discharging required power PB* of the in-vehicle battery 27. The charging / discharging required power PB* is set according to the deviation between the state of charge SOC of the in-vehicle battery 27 and its target value, i.e., the target state of charge. Note that a positive value is set for the charging / discharging required power PB* when the state of charge SOC is greater than the target state of charge, and a negative value is set when the state of charge SOC is less than the target state of charge, respectively.

[0026] Next, the CPU 31 calculates, as the value of the engine required power PE*, the value obtained by subtracting the charging / discharging required power PB* from the required driving force PD*. The engine required power PE* represents the required value of the power generated by the engine 10.

[0027] Next, on the operating line of the engine 10 capable of generating power according to the engine required power PE*, the CPU 31 selects an operating point that is advantageous in terms of fuel consumption performance and exhaust performance. Then, the CPU 31 sets the engine speed NE and the engine load ratio KL of the selected operating point as the target engine speed NE* and the target engine load ratio KL*, respectively. Note that the engine load ratio KL represents the intake charge ratio of the cylinder 11.

[0028] Subsequently, the CPU 31 operates the opening degree of the throttle valve 14 so as to bring the engine load ratio KL closer to the target engine load ratio KL*. Note that the CPU 31 calculates the actual engine load ratio KL based on the engine speed NE and the intake air flow rate GA. Also, the engine speed NE is calculated by the CPU 31 based on the detection signal of the crank angle sensor 34. Further, the CPU 31 calculates, as the fuel injection amount of the injector 16, the amount at which the air-fuel ratio of the air-fuel mixture combusted in the cylinder 11 becomes the target air-fuel ratio based on the engine load ratio KL. Then, the CPU 31 operates the injector 16 of each cylinder 11 so as to perform fuel injection corresponding to the calculated fuel injection amount.

[0029] Further, the CPU 31 sets a first required torque TM1* based on the deviation of the engine speed NE from the target engine speed NE*. The first required torque TM1* represents the required value of the torque for the first rotating electric machine M1. More specifically, the CPU 31 performs feedback adjustment of the first required torque TM1* so as to bring the above deviation closer to "0". Then, the CPU 31 operates the first inverter 25 to generate a torque corresponding to the first required torque TM1* in the first rotating electric machine M1.

[0030] On the other hand, the CPU 31 calculates a second required torque TM2* based on the required drive torque TD* and the direct torque TED. The second required torque TM2* represents the required value of the torque for the second rotating electric machine M2. The direct torque TED represents the torque actually output from the power split mechanism 20 to the speed reduction mechanism 21. The CPU 31 calculates the direct torque TED based on the first required torque TM1* and the like. Then, the CPU 31 operates the second inverter 26 to generate a torque corresponding to the second required torque TM2* in the second rotating electric machine M2.

[0031] <Filter regeneration control> The filter device 15B installed in the exhaust passage 13 of the engine 10 may become clogged due to the deposition of PM. The CPU 31 executes filter regeneration control to purify the deposited PM and regenerate the filter device 15B before the filter device 15B becomes clogged.

[0032] Fig. 3 shows the procedure of the filter regeneration control. The process shown in Fig. 3 is realized by the CPU 31 repeatedly executing the program stored in the ROM 32 at each predetermined control cycle. In the following, the step numbers of each process are represented by numbers with "S" added at the beginning.

[0033] In the series of processes shown in FIG. 3, the CPU 31 first acquires the engine rotational speed NE, the charging efficiency η, and the engine coolant temperature THW (S10). The engine rotational speed NE is calculated by the CPU 31 based on the output signal of the crank angle sensor 34. Also, the charging efficiency η is calculated by the CPU 31 based on the intake air flow rate GA and the engine rotational speed NE. Next, the CPU 31 calculates an update amount ΔDPM of the deposition amount DPM, which is the amount of PM collected by the filter device 15B, based on the engine rotational speed NE, the charging efficiency η, and the engine coolant temperature THW (S12). Here, the CPU 31 calculates the amount of PM in the exhaust gas discharged into the exhaust passage 13 based on the engine rotational speed NE, the charging efficiency η, and the engine coolant temperature THW. Also, the CPU 31 calculates the temperature of the filter device 15B based on the engine rotational speed NE and the charging efficiency η. Then, the CPU 31 calculates the update amount ΔDPM based on the amount of PM in the exhaust gas and the temperature of the filter device 15B. Note that the CPU 31 may calculate the update amount ΔDPM in consideration of the air-fuel ratio in the cylinder where combustion control is continued during the execution of the process in S20 described later.

[0034] Next, the CPU 31 updates the deposition amount DPM according to the update amount ΔDPM (S14). Next, the CPU 31 determines whether the flag F is "1" (S16). When the flag F is "1", it indicates that the regeneration process for burning and removing the PM of the filter device 15B is being executed, while when it is "0", it indicates otherwise. When the CPU 31 determines that it is "0" (S16: NO), it determines whether the deposition amount DPM is equal to or greater than the regeneration execution value DPMH (S18). The regeneration execution value DPMH is set to a value at which the amount of PM collected by the filter device 15B is large and it is desirable to remove the PM. When the CPU 31 determines that it is equal to or greater than the regeneration execution value DPMH (S18: YES), it executes the regeneration process and assigns "1" to the flag F (S20). That is, the CPU 31 stops the fuel injection from the injector 16 of any one of the four cylinders 11. Further, the CPU 31 makes the air-fuel ratio of the air-fuel mixture in the remaining cylinders richer than the stoichiometric air-fuel ratio. This process is for discharging oxygen and unburned fuel into the exhaust passage 13 and raising the temperature of the filter device 15B to burn and remove the PM collected by the filter device 15B. That is, by discharging oxygen and unburned fuel into the exhaust passage 13, the unburned fuel is burned in the catalyst device 15A or the like to raise the temperature of the exhaust gas. Thereby, the temperature of the filter device 15B can be raised. Also, by supplying oxygen to the filter device 15B, the PM collected by the filter device 15B can be burned and removed.

[0035] The CPU 31 periodically switches the cylinder in which the fuel injection is stopped. The switching period is, for example, a predetermined multiple of one combustion cycle. Here, the predetermined number may be, for example, a number of 100 or more.

[0036] On the other hand, when the CPU 31 determines that the flag F is "1" (S16: YES), the CPU 31 determines whether the accumulation amount DPM is equal to or smaller than the stop threshold value DPML (S22). The stop threshold value DPML is set to a value at which the amount of PM trapped in the filter device 15B becomes small enough to allow the regeneration process to be stopped. When the CPU 31 determines that the accumulation amount DPM exceeds the stop threshold value DPML (S22: NO), the CPU 31 proceeds to the process of S20. When the CPU 31 determines that the accumulation amount DPM is equal to or smaller than the stop threshold value DPML (S22: YES), the CPU 31 stops the regeneration process and sets the flag F to "0" (S24).

[0037] When the CPU 31 completes the processes of S20 and S24, or when a negative determination is made in the process of S18, the CPU 31 temporarily ends the series of processes shown in FIG. <Vibration control> During the execution of the combustion stop process in the filter regeneration control, no combustion torque is generated at the time when the cylinder 11 where combustion has stopped would normally perform combustion, and so the torque of the engine 10 decreases. Meanwhile, the planetary carrier C tries to maintain its previous rotation speed due to inertia, and the torsion of the torsional damper 19 increases. When combustion occurs in the cylinder 11 that will undergo the combustion stroke after the cylinder 11 where combustion has stopped, the torque of the engine 10 increases. At this time, the torsion stored in the torsional damper 19 is released, causing the engine 10 to vibrate. The vibration of the engine 10 is then transmitted to the vehicle body B via the engine mount 10B.

[0038] In addition, the torque fluctuation of the engine 10 caused by the execution of the combustion stop process is also transmitted to the drive shaft 23 of the wheels 24 via the power split mechanism 20, the reduction mechanism 21, and the differential mechanism 22. As a result, the rotation of the wheels 24 becomes uneven, causing the vehicle body B to vibrate for the front and rear.

[0039] During the execution of the combustion stop process in this way, vibrations due to torque fluctuations of the engine 10 are transmitted to the vehicle body B through two paths, increasing the vehicle body vibration. In the following description, the vibration transmission path to the vehicle body B via the engine mount 10B is referred to as the mount path P1. Also, the vibration transmission path to the vehicle body B via the drive shaft 23 of the wheel 24 is referred to as the drive shaft path P2.

[0040] During the execution of the combustion stop process, the CPU 31 executes vibration damping control to generate vibration damping torque for suppressing vibration transmission to the vehicle body B for each of the first electric motor M1 and the second electric motor M2. The details of such vibration damping control will be described below.

[0041] Figures 4 and 5 show the procedure of the vibration damping control. The processes shown in Figures 4 and 5 are realized by the CPU 31 repeatedly executing the program stored in the ROM 32 at a predetermined control cycle.

[0042] In the series of processes shown in Figures 4 and 5, the CPU 31 first determines whether or not the combustion stop process is being executed (S200). That is, the CPU 31 determines whether or not the flag F is "1". If the combustion stop process is being executed (S200: YES), the CPU 31 determines the necessity of vibration damping based on the engine rotational speed NE and the filling efficiency η (S210). When the engine rotational speed NE is high, even if the combustion stop process is executed, the period during which the combustion torque decreases is short, so the vehicle body vibration is less noticeable. Also, when the filling efficiency η is small, even if the combustion stop process is executed, the combustion torque is small, so the vehicle body vibration is less noticeable. Therefore, the CPU 31 determines that vibration damping is unnecessary in these cases.

[0043] When it is determined that vibration suppression is necessary (S210: YES), the CPU 31 determines whether or not it is possible to generate vibration suppression torque by the first rotating electric machine M1 and the second rotating electric machine M2 (S220). A state in which vibration suppression torque cannot be generated is, for example, a case where there is an abnormality in the electric system of a hybrid vehicle or a case where sufficient cooling of the electric system cannot be performed. When it is not possible to generate vibration suppression torque (S220: NO), the CPU 31 performs vibration suppression of vehicle body vibration by means other than the generation of vibration suppression torque, such as changing the operating point of the engine 10 (S350).

[0044] On the other hand, when it is in a state where vibration suppression torque can be generated (S220: YES), the CPU 31 calculates a first vibration suppression torque Δ1, which is the vibration suppression torque to be generated in the first rotating electric machine M1 (S230). Further, the CPU 31 calculates a second vibration suppression torque Δ2, which is the vibration suppression torque to be generated in the second rotating electric machine M2 (S240).

[0045] FIG. 6(B) shows the transition of the engine torque during the execution of the combustion stop process, and FIG. 6(C) shows the transition of the first vibration suppression torque Δ1 calculated by the CPU 31. Further, FIG. 6(D) shows the transition of the drive shaft torque, which is the torque of the drive shaft 23 of the wheel 24, and FIG. 6(E) shows the transition of the second vibration suppression torque Δ2 calculated by the CPU 31. Note that FIG. 6(A) shows the cylinder numbers of the cylinders 11 during the combustion stroke. FIG. 6 shows a case where the engine 10 has four cylinders 11 with cylinder numbers #1, #2, #3, and #4, and the combustion of the cylinder 11 with cylinder number #2 is stopped by the combustion stop process. Further, in FIG. 6, the combustion order of each cylinder 11 is in the order of #1 → #3 → #4 → #2.

[0046] As shown in FIG. 6(B), the engine torque decreases after the start of the combustion stroke of cylinder 11 of cylinder number #2 where combustion has stopped. As shown in FIG. 6(C), the CPU 31 sets the value of the first vibration damping torque Δ1 such that the value becomes "0" except during the period of engine torque decrease, and during the period of engine torque decrease, the value decreases at the same period as the period of engine torque decrease. In the present embodiment, the CPU 31 calculates the first vibration damping torque Δ1 based on the engine rotational speed NE, the engine load factor KL, and the cylinder number of cylinder 11 where combustion is stopped. And when the amplitude of the engine torque fluctuation associated with the execution of the combustion stop process is large, the CPU 31 calculates the value of the first vibration damping torque Δ1 to be larger than when the amplitude is small. Thus, the CPU 31 sets the first vibration damping torque Δ1 by feedforward.

[0047] As shown in FIG. 6(D), the drive shaft torque during the combustion stop process decreases with a delay after the decrease in the engine torque. As shown in FIG. 6(E), the CPU 31 sets the value of the second vibration damping torque Δ2 such that the value becomes "0" except during the period of drive shaft torque decrease, and during the period of drive shaft torque decrease, the value increases in conjunction with the decrease in the drive shaft torque. That is, a positive value is set for the second vibration damping torque Δ2 during the period of drive shaft torque decrease. In the present embodiment, the CPU 31 calculates the drive shaft torque from the detection result of the output rotation speed sensor 36. And the CPU 31 calculates the second vibration damping torque Δ2 based on the calculated drive shaft torque. Specifically, when the amplitude of the drive shaft torque fluctuation associated with the execution of the combustion stop process is large, the CPU 31 calculates the value of the second vibration damping torque Δ2 to be larger than when the amplitude is small. Thus, the CPU 31 sets the second vibration damping torque Δ2 by feedback based on the drive shaft torque.

[0048] In the series of processes shown in FIGS. 4 and 5, after calculating the second vibration damping torque Δ2 in S240, the CPU 31 sets a gain G1A applied to the first vibration damping torque Δ1 and a gain G2A applied to the second vibration damping torque Δ2 based on the engine rotational speed NE (S250). The CPU 31 sets the gain G1A to take a value of "0" or more and to be larger when the engine rotational speed NE is low than when it is high. On the other hand, the CPU 31 sets the gain G2A to take a value of "0" or more and to be larger when the engine rotational speed NE is high than when it is low.

[0049] Next, the CPU 31 sets a gain G1B applied to the first vibration damping torque Δ1 and a gain G2B applied to the second vibration damping torque Δ2 based on the state of charge SOC of the in-vehicle battery 27 (S260). The CPU 31 sets the gain G1B to take a value of "0" or more and to be smaller when the state of charge SOC is high than when it is low. Also, the CPU 31 sets the gain G2B to take a value of "0" or more and to be larger when the state of charge SOC is high than when it is low.

[0050] Next, the CPU 31 sets a gain G1C applied to the first vibration damping torque Δ1 and a gain G2C applied to the second vibration damping torque Δ2 based on the battery temperature THB (S270). The CPU 31 sets the gain G1C to take a value of "0" or more and to be larger when the battery temperature THB is high than when it is low. Also, the CPU 31 sets the gain G2C to take a value of "0" or more and to be smaller when the battery temperature THB is high than when it is low.

[0051] Next, the CPU 31 sets a gain G1D applied to the first vibration damping torque Δ1 and a gain G2D applied to the second vibration damping torque Δ2 based on the charging duration (S280). When the charging duration is less than the preset time T1, the CPU 31 sets the values of the gain G1D and the gain G2D to "1", respectively. Also, when the charging duration is equal to or greater than the preset time T1, the CPU 31 sets the gain G1D to take a value of "0" or more and gradually decrease from "1" as the charging duration increases from the preset time T1. Further, when the charging duration is equal to or greater than the preset time T1, the CPU 31 sets the gain G2D to gradually increase from "1" as the charging duration increases from the preset time T1.

[0052] Next, the CPU 31 sets a gain G1E applied to the first vibration damping torque Δ1 and a gain G2E applied to the second vibration damping torque Δ2 based on the discharging duration (S290). When the discharging duration is less than the preset time T2, the CPU 31 sets the values of the gain G1E and the gain G2E to "1", respectively. Also, when the discharging duration is equal to or greater than the preset time T2, the CPU 31 sets the gain G1E to gradually increase from "1" as the discharging duration increases from the preset time T2. Further, when the discharging duration is equal to or greater than the preset time T2, the CPU 31 sets the gain G2E to take a value of "0" or more and gradually decrease from "1" as the discharging duration increases from the preset time T2.

[0053] Next, the CPU 31 sets a gain G1F applied to the first vibration damping torque Δ1 and a gain G2F applied to the second vibration damping torque Δ2 based on the integrated current of the in-vehicle battery 27 (S300). The integrated current is the integrated value of the charging current and the discharging current of the in-vehicle battery 27 over a preset period until now. The CPU 31 sets the gain G1F to take a value of "0" or more and be larger when the integrated current is large than when it is small. Also, the CPU 31 sets the gain G2F to take a value of "0" or more and be smaller when the integrated current is large than when it is small.

[0054] Subsequently, the CPU 31 performs mediation processing on the gains G1A to G1F applied to the first vibration damping torque Δ1, and finally sets the value of the first gain G1 applied to the first vibration damping torque Δ1 (S310). In the adjustment process, the CPU 31 selects the value with the highest priority among the gains G1A to G1F and sets it as the value of the first gain G1. Further, the CPU 31 performs mediation processing on the gains G2A to G2F applied to the second vibration damping torque Δ2 to set the second gain G2 (S320).

[0055] Subsequently, the CPU 31 adds the value obtained by multiplying the first vibration damping torque Δ1 by the first gain G1 to the first required torque TM1*. Then, the CPU 31 calculates the added value as the command value TM1 of the torque generated in the first rotating electric machine M1 (S330). The CPU 31 operates the first inverter 25 according to this command value TM1. Also, the CPU 31 adds the value obtained by multiplying the second vibration damping torque Δ2 by the second gain G2 to the second required torque TM2*. Then, the CPU 31 calculates the added value as the command value TM2 of the torque generated in the second rotating electric machine M2 (S340). The CPU 31 operates the second inverter 26 according to this command value TM2.

[0056] Note that when the CPU 31 finishes the processes of S340 and S350, and when a negative determination is made in S200 and S210, the CPU 31 ends the series of processes shown in FIGS. 4 and 5. <Operational Effects of the Embodiment> In the series of processes shown in FIGS. 4 and 5, the CPU 31 sets "TM1* + Δ1 × G1" as the command value TM1 for the torque generated in the first rotating electric machine M1. That is, in the vibration damping control, the CPU 31 superimposes "Δ1 × G1" on the required torque of the first rotating electric machine M1 in the driving force control. The first vibration damping torque Δ1 is set to be a negative value during the period of engine torque reduction due to the combustion stop process, and the first gain G1 is a positive value. Therefore, in the vibration damping control, the CPU 31 reduces the torque of the first rotating electric machine M1 in conjunction with the reduction of the engine torque due to the combustion stop process. The torque of the first rotating electric machine M1 is transmitted to the planetary carrier C of the power split mechanism 20. Therefore, the rotational torque of the planetary carrier C also decreases as the engine torque decreases due to the combustion stop of some of the cylinders 11 in the combustion stop process. As a result, the torsion of the torsional damper 19 associated with the decrease in the engine torque is alleviated, and the vibration of the engine 10 associated with the release of the torsion becomes smaller. And as a result, the vibration transmitted to the vehicle body B through the mount path P1 is suppressed. Thus, by generating the vibration damping torque in the first rotating electric machine M1, the vibration transmission to the vehicle body B via the mount path P1 can be suppressed. Note that the first rotating electric machine M1 is not directly transmitted to the drive shaft 23 of the wheel 24. Therefore, the generation of the vibration damping torque by the first rotating electric machine M1 has a limited effect on suppressing the vibration transmission to the vehicle body B via the drive shaft path P2. In the following description, the process for generating the vibration damping torque in such a first rotating electric machine M1 is described as the first vibration damping process. The first vibration damping process is a series of processes related to S340 in FIG. 4 and the calculation of the command value TM1. Note that the first required torque TM1* is basically set to a negative value in the driving force control. Therefore, the first rotating electric machine M1 generates electricity during the execution of the first vibration damping process, and the generation of the vibration damping torque is accompanied by an increase in the power generation amount.

[0057] Also, in the series of processes shown in FIGS. 4 and 5, the CPU 31 sets "TM2* + Δ2 × G2" as the command value TM1 of the torque to be generated in the second rotating electric machine M2. That is, in the vibration damping control, the CPU 31 superimposes "Δ2 × G2" on the required torque of the second rotating electric machine M2 in the driving force control. The second vibration damping torque Δ2 is set to be a positive value during the period when the driving shaft torque decreases due to the combustion stop process, and the second gain G2 is a positive value. Therefore, in the vibration damping control, the CPU 31 increases the torque of the second rotating electric machine M2 in conjunction with the decrease in the driving shaft torque due to the combustion stop process. The second rotating electric machine M2 is mechanically connected to the drive shaft 23 of the wheel 24 via the reduction mechanism 21 and the differential mechanism 22. If the torque of the second rotating electric machine M2 is increased in conjunction with the decrease in the driving shaft torque, the fluctuation of the driving shaft torque is alleviated. Therefore, by generating the vibration damping torque in the second rotating electric machine M2, the vibration transmission to the vehicle body B via the drive shaft path P2 can be suppressed. Note that the torque of the second rotating electric machine M2 is not directly transmitted to the crankshaft 10A. Therefore, the generation of the vibration damping torque by the second rotating electric machine M2 has a limited effect on suppressing the vibration transmission to the vehicle body B via the mount path P1. In the following description, the process for generating the vibration damping torque in the second rotating electric machine M2 is described as the second vibration damping process. The second vibration damping process is a series of processes related to S360 in FIG. 5 and the calculation of the command value TM2. Note that the second required torque TM2* can be either positive or negative depending on the situation. Also, within the range of the limitation by the state of charge SOC of the in-vehicle battery 27, the value of the second required torque TM2* can be adjusted to some extent.

[0058] Note that when the value of the first gain G1 is increased, the amplitude of the vibration damping torque superimposed on the torque of the first rotating electric machine M1 becomes larger. On the other hand, when the value of the first gain G1 is decreased, the amplitude of the vibration damping torque superimposed on the torque of the first rotating electric machine M1 becomes larger. Thus, by adjusting the first gain G1, the amplitude of the vibration damping torque of the first rotating electric machine M1 generated by the first vibration damping process is adjusted.

[0059] Further, when the value of the second gain G2 is increased, the amplitude of the vibration damping torque superimposed on the torque of the second rotating electrical machine M2 increases. On the other hand, when the value of the second gain G2 is decreased, the amplitude of the vibration damping torque superimposed on the torque of the second rotating electrical machine M2 increases. Thus, depending on the adjustment of the second gain G2, the amplitude of the vibration damping torque of the first rotating electrical machine M1 generated by the second vibration damping process is adjusted.

[0060] In the series of processes shown in FIGS. 4 and 5, the CPU 31 sets the first gain G1 and the second gain G2 based on the engine rotational speed NE, the state of charge SOC, the battery temperature THB, the charging duration, the discharging duration, and the integrated current. That is, the CPU 31 adjusts the amplitude of the vibration damping torque generated in each of the first vibration damping process and the second vibration damping process in the vibration damping control according to these.

[0061] (Adjustment of the amplitude of the vibration damping torque according to the engine rotational speed NE) In S250 of FIG. 4, the CPU 31 sets the gain G1A applied to the first vibration damping torque Δ1 and the gain G2A applied to the second vibration damping torque Δ2 based on the engine rotational speed NE. In S250, the CPU 31 sets the gain G1A to be a larger value when the engine rotational speed NE is low than when the engine rotational speed NE is high. Further, the CPU 31 sets the gain G2A to be a smaller value when the engine rotational speed NE is low than when the engine rotational speed NE is high. That is, when the engine rotational speed NE is low, the CPU 31 adjusts the amplitude of the vibration damping torque generated in the first vibration damping process to the side of decreasing and the amplitude of the vibration damping torque generated in the second vibration damping process to the side of increasing, respectively. Further, when the engine rotational speed NE is high, the CPU 31 adjusts the amplitude of the vibration damping torque generated in the first vibration damping process to the side of increasing and the amplitude of the vibration damping torque generated in the second vibration damping process to the side of decreasing, respectively.

[0062] Note that, as described above, the first vibration damping torque Δ1 is calculated such that when the fluctuation of the engine torque due to the combustion stop process is large, it has a larger value than when the fluctuation is small. Therefore, when the engine rotational speed NE is low, the ratio of the amplitude of the vibration damping torque generated by the first vibration damping process to the amplitude of the fluctuation of the engine torque due to the combustion stop process is larger than when the engine rotational speed NE is high.

[0063] FIG. 7 shows the relationship between the intensity of the vibration transmitted to the vehicle body B via each of the mount path P1 and the drive shaft path P2 and the engine rotational speed NE. As shown in FIG. 7, when the engine rotational speed NE is low, the intensity of the vibration transmitted via the mount path P1 is larger than the intensity of the vibration transmitted via the drive shaft path P2. At this time, even if the amplitude of the vibration damping torque in the second vibration damping process is increased to suppress the fluctuation of the drive shaft torque, the resulting effect of suppressing the vehicle body vibration is limited. On the other hand, if the amplitude of the vibration damping torque in the first vibration damping process is increased to suppress the vibration of the engine 10, the vehicle body vibration is significantly reduced.

[0064] Note that, as described above, the second vibration damping torque Δ2 is calculated such that when the fluctuation of the drive shaft torque due to the combustion stop process is large, it has a larger value than when the fluctuation is small. Therefore, when the engine rotational speed NE is high, the ratio of the amplitude of the vibration damping torque generated by the second vibration damping process to the amplitude of the fluctuation of the drive shaft torque due to the combustion stop process is larger than when the engine rotational speed NE is low.

[0065] Note that when the amplitude of the vibration damping torque is increased, the current increases and the load on the electrical system of the hybrid vehicle increases. Even if the amplitude of the vibration damping torque generated by the first vibration damping process is increased, if the amplitude of the vibration damping torque generated by the second vibration damping process is decreased, the current decreases accordingly. In the present embodiment, when the engine rotational speed NE is low, the amplitude of the vibration damping torque generated by the first vibration damping process is adjusted to be increased, and the amplitude of the vibration damping torque generated by the second vibration damping process is adjusted to be decreased. Therefore, the vehicle body vibration when the engine rotational speed NE is low can be effectively suppressed while suppressing the increase in current.

[0066] On the other hand, when the engine rotational speed NE is high, the intensity of the vibration transmitted via the drive shaft path P2 is greater than the intensity of the vibration transmitted via the mount path P1. In contrast, in the present embodiment, when the engine rotational speed NE is high, the amplitude of the vibration damping torque generated in the first vibration damping process is adjusted to be reduced, and the amplitude of the vibration damping torque generated in the second vibration damping process is adjusted to be increased. Therefore, even for the vehicle body vibration when the engine rotational speed NE is high, it can be effectively suppressed while suppressing the increase in current.

[0067] (Adjustment of the amplitude of the vibration damping torque according to the state of charge SOC of the in-vehicle battery 27) In S260 of FIG. 4, the CPU 31 sets the gain G1B applied to the first vibration damping torque Δ1 and the gain G2B applied to the second vibration damping torque Δ2 based on the state of charge SOC of the in-vehicle battery 27. In S260, the CPU 31 sets the gain G1B to be a larger value when the state of charge SOC is low than when it is high. Also, the CPU 31 sets the gain G2B to be a smaller value when the state of charge SOC is low than when it is high. That is, when the state of charge SOC is high, the CPU 31 adjusts the amplitude of the vibration damping torque generated in the first vibration damping process to be increased and the amplitude of the vibration damping torque generated in the second vibration damping process to be decreased, respectively. Also, when the state of charge SOC is high, the CPU 31 adjusts the amplitude of the vibration damping torque generated in the first vibration damping process to be decreased and the amplitude of the vibration damping torque generated in the second vibration damping process to be increased, respectively.

[0068] When the state of charge (SOC) of the in-vehicle battery 27 is low, if the discharge current increases, the SOC may further decrease, leading to over-discharge of the in-vehicle battery 27. In the first vibration damping process, vibration damping torque is generated to reduce the torque of the first rotating electric machine M1 at the same period as the period of the engine torque reduction. When the amplitude of the vibration damping torque generated in such first vibration damping process is increased, the charging current of the in-vehicle battery 27 increases. On the other hand, in the second vibration damping process, vibration damping torque is generated to increase the torque of the second rotating electric machine M2 in conjunction with the reduction of the drive shaft torque. When the amplitude of the vibration damping torque generated in such second vibration damping process is increased, the discharge current of the in-vehicle battery 27 decreases. Therefore, by adjusting the amplitudes of the vibration damping torques of the first and second vibration damping processes when the SOC is low as described above, the discharge current decreases and the charging current increases, making it difficult for over-discharge of the in-vehicle battery 27 to occur. Note that the decrease in the vehicle body vibration suppression effect due to the reduction of the amplitude of the vibration damping torque generated in the second vibration damping process can be compensated by the increase in the amplitude of the vibration damping torque generated in the first vibration damping process.

[0069] On the other hand, when the SOC is high, if the charging current increases, the in-vehicle battery 27 may be overcharged. When the amplitude of the vibration damping torque generated in the first vibration damping process is decreased, the charging current decreases, and when the amplitude of the vibration damping torque generated in the second vibration damping process is increased, the discharge current decreases. Therefore, by adjusting the amplitudes of the vibration damping torques of the first and second vibration damping processes when the SOC is high as described above, the discharge current increases and the charging current decreases, making it difficult for overcharging of the in-vehicle battery 27 to occur. Note that the decrease in the vehicle body vibration suppression effect due to the reduction of the amplitude of the vibration damping torque generated in the first vibration damping process can be compensated by the increase in the amplitude of the vibration damping torque generated in the second vibration damping process.

[0070] (Adjustment of the amplitude of the vibration damping torque according to the battery temperature THB) In S270 of FIG. 4, the CPU 31 sets the gain G1C applied to the first vibration damping torque Δ1 so that it has a larger value when the battery temperature THB is high than when it is low. Also in S270, the CPU 31 sets the gain G2C applied to the second vibration damping torque Δ2 so that it has a smaller value when the battery temperature THB is high than when it is low. That is, when the battery temperature THB is high, the CPU 31 increases the amplitude of the vibration damping torque generated in the first vibration damping process and decreases the amplitude of the vibration damping torque generated in the second vibration damping process compared to when the battery temperature THB is low.

[0071] As described above, in the driving force control, basically, a negative value is set for the first required torque TM1* to regeneratively drive the first rotating electric machine M1. Also, in the first vibration damping process, a vibration damping torque is generated on the side where the torque is reduced. Therefore, if the amplitude of the vibration damping torque generated in the first vibration damping process is increased, inevitably, the peak value of the charging current increases. On the other hand, when the battery temperature THB is low, the charge and discharge capacity of the in-vehicle battery 27 decreases. Thus, in a state where the charge and discharge are restricted due to a low battery temperature THB, the amplitude of the vibration damping torque generated in the first vibration damping process is also restricted. On the other hand, the amplitude of the vibration damping torque generated in the second vibration damping process is less likely to be subject to such restrictions. Therefore, if the amplitude of the vibration damping torque is adjusted based on the battery temperature THB as described above, it becomes easier to ensure the effect of suppressing vehicle body vibration even in a state where the charge and discharge of the in-vehicle battery 27 are restricted by the battery temperature THB. In this case, it is desirable to adjust the feedback center of the second vibration damping torque Δ2 so that the balance of the charge and discharge of the in-vehicle battery 27 with the second rotating electric machine M2 becomes a value close to zero.

[0072] (Adjustment of the amplitude of the vibration damping torque according to the charge duration and the discharge duration) If charging continues for a time longer than a certain level, the charging capacity of in-vehicle battery 27 decreases. In S280 of FIG. 5, when the charging duration is equal to or longer than a preset time T1, CPU 31 decreases the gain G1D applied to the first vibration damping torque Δ1 while increasing the gain G2D applied to the second vibration damping torque Δ2. That is, when the charging of in-vehicle battery 27 continues for a time equal to or longer than the preset time T1, CPU 31 reduces the amplitude of the vibration damping torque generated in the first vibration damping process and increases the amplitude of the vibration damping torque generated in the second vibration damping process compared to when it is not continuing. Therefore, even when charging is restricted, the effect of suppressing vehicle body vibration can be ensured.

[0073] On the other hand, when the discharge of in-vehicle battery 27 continues for a time longer than a certain level, the discharge capacity of in-vehicle battery 27 decreases. In S290 of FIG. 5, when the discharge duration is equal to or longer than a preset time T2, CPU 31 increases the gain G1D applied to the first vibration damping torque Δ1 while decreasing the gain G2D applied to the second vibration damping torque Δ2. That is, when the discharge of in-vehicle battery 27 continues for a time equal to or longer than the preset time T2, CPU 31 increases the amplitude of the vibration damping torque generated in the first vibration damping process and reduces the amplitude of the vibration damping torque generated in the second vibration damping process compared to when it is not continuing. Therefore, even when discharge is restricted, the effect of suppressing vehicle body vibration can be ensured. Note that increasing the amplitude of the braking torque generated in the first vibration damping process and increasing the regeneration amount of the first rotating electrical machine M1 also helps to eliminate the ion bias of the electrolyte, which is the cause of the decrease in the discharge capacity of in-vehicle battery 27.

[0074] (Adjustment of the amplitude of the vibration damping torque by the integrated current) If a large current continues to flow in the electrical system of a hybrid vehicle, electrical circuit components such as the first inverter 25 and the second inverter 26 become hot. When the positive and negative reversals of the current flowing through the electrical circuit components are repeated, the heat generation of the components increases.

[0075] As described above, in the driving force control, basically, a negative value is set for the first required torque TM1* to regeneratively drive the first rotating electric machine M1. Also, in the first vibration damping process, a vibration damping torque is generated on the side where the torque is reduced. Therefore, the current between the first rotating electric machine M1 and the in-vehicle battery 27 during the execution of the first vibration damping process is maintained within the negative range. On the other hand, since either a positive or negative value is set for the second required torque TM2* depending on the situation, the current flowing between the second rotating electric machine M2 and the in-vehicle battery 27 may reverse in polarity during the execution of the second vibration damping process. And the possibility of this current polarity reversal increases as the amplitude of the vibration damping torque generated in the second vibration damping process becomes larger.

[0076] In contrast, in the present embodiment, in S300 of FIG. 5, the CPU 31 sets a larger value for the gain G1F applied to the first vibration damping torque Δ1 when the integrated current is large than when it is small. On the other hand, also in S300, the CPU 31 sets a smaller value for the gain G2F applied to the second vibration damping torque Δ2 when the integrated current is large than when it is small. That is, the CPU 31 adjusts the amplitude of the vibration damping torque generated in the first vibration damping process to increase and the amplitude of the vibration damping torque generated in the second vibration damping process to decrease, respectively, when the integrated current is large. Therefore, while avoiding overheating of the electric circuit components, the effect of suppressing vehicle body vibration can be ensured.

[0077] The control device 30 of the hybrid vehicle according to the present embodiment described above has the following effects. (1) When the engine rotation speed NE is low, the CPU 31 adjusts to increase the amplitude of the vibration damping torque of the first rotating electric machine M1 generated by the first vibration damping process. That is, when the engine rotation speed NE is low, the CPU 31 makes the ratio of the amplitude of the vibration damping torque generated by the first vibration damping process to the amplitude of the fluctuation of the engine torque due to the combustion stop process larger than when the engine rotation speed NE is high. Also, when the engine rotation speed NE is high, the CPU 31 adjusts to increase the amplitude of the vibration damping torque of the second rotating electric machine M2 generated by the second vibration damping process. That is, when the engine rotation speed NE is high, the CPU 31 makes the ratio of the amplitude of the vibration damping torque generated by the second vibration damping process to the amplitude of the fluctuation of the drive shaft torque due to the combustion stop process larger than when the engine rotation speed NE is low. Therefore, effective vibration damping control can be performed according to the change in the vibration transmission path to the vehicle body B due to the engine rotation speed NE.

[0078] (2) When the engine rotation speed NE is low, the CPU 31 adjusts to decrease the amplitude of the vibration damping torque of the second rotating electric machine M2 generated by the second vibration damping control. Also, when the engine rotation speed NE is high, the CPU 31 adjusts to decrease the amplitude of the vibration damping torque of the first rotating electric machine M1 generated by the first vibration damping process. When the engine rotation speed NE is low, since the vibration transmission through the drive shaft path P2 decreases, even if the amplitude of the vibration damping torque of the second rotating electric machine M2 generated by the second vibration damping control is decreased, the vibration transmission to the vehicle body B can be sufficiently suppressed. On the other hand, when the engine rotation speed NE is high, since the vibration transmission through the mount path P1 decreases, even if the amplitude of the vibration damping torque of the first rotating electric machine M1 generated by the first vibration damping control is decreased, the vibration transmission to the vehicle body B can be sufficiently suppressed. Therefore, efficient vibration damping control can be performed.

[0079] (3) In the first vibration damping process, the CPU 31 generates a vibration damping torque so as to decrease the torque of the first rotating electric machine M1 in the same period as the period of the decrease in the engine torque. Thereby, by relaxing the torsion of the torsional damper 19, the vibration transmission to the vehicle body B through the mount path P1 can be effectively suppressed.

[0080] (4) When the state of charge (SOC) of the in-vehicle battery 27 is high, the CPU 31 reduces the amplitude of the vibration damping torque generated in the first vibration damping process compared to when the SOC is low. When the amplitude of the vibration damping torque generated in the first vibration damping process is reduced, the regenerative power generation amount of the first rotating electrical machine M1 decreases, and the charge amount of the in-vehicle battery 27 decreases. Therefore, overcharging of the in-vehicle battery 27 is less likely to occur. Further, when the SOC of the in-vehicle battery 27 is high, the CPU 31 increases the amplitude of the vibration damping torque generated in the second vibration damping process compared to when the SOC is low. Therefore, while avoiding overcharging of the in-vehicle battery 27, vehicle body vibration can be effectively suppressed.

[0081] (5) When the battery temperature THB is low, the CPU 31 increases the amplitude of the vibration damping torque generated in the second vibration damping process compared to when the battery temperature THB is high. When the battery temperature THB is low, the charge and discharge of the in-vehicle battery 27 are restricted. On the other hand, in the first vibration damping process, the vibration damping torque is generated by the regenerative drive of the first rotating electrical machine M1. Therefore, when the battery temperature THB is low, the generation of the vibration damping torque in the first vibration damping process may be restricted. In contrast, in the second vibration damping process, by adjusting the feedback center of the second vibration damping torque Δ2, the balance of charge and discharge can be made close to zero, so it is difficult to restrict the generation of the vibration damping torque even when the battery temperature THB is low. Therefore, as described above, even when the battery temperature THB is low, the effect of suppressing vehicle body vibration can be maintained. Further, when the battery temperature THB is low, the CPU 31 reduces the amplitude of the vibration damping torque generated in the first vibration damping process compared to when the battery temperature THB is high. Therefore, the first vibration damping process can be performed within a range that can be implemented under the charge and discharge restrictions when the battery temperature THB is low.

[0082] (6) When the charging of in - vehicle battery 27 continues for a preset time T1 or more, the CPU 31 increases the amplitude of the vibration damping torque generated in the second vibration damping process compared to the case where it does not continue. When the charging of in - vehicle battery 27 continues for a time longer than a certain level, the charging capacity of in - vehicle battery 27 decreases. The second vibration damping process is less restricted in generating vibration damping torque due to the charging limit of in - vehicle battery 27 compared to the first vibration damping process. Therefore, as described above, even if the charging capacity of in - vehicle battery 27 decreases due to continuous charging, the suppression effect of vehicle body vibration is less likely to decrease. Further, when the charging of in - vehicle battery 27 continues for a preset time T1 or more, the CPU 31 decreases the amplitude of the vibration damping torque generated in the first vibration damping process compared to the case where it does not continue. Therefore, even with the decreased charging capacity of in - vehicle battery 27 due to continuous charging, the first vibration damping process can be implemented within an acceptable range.

[0083] (7) When the discharging of in - vehicle battery 27 continues for a preset time T2 or more, the CPU 31 increases the amplitude of the vibration damping torque generated in the first vibration damping process compared to the case where it does not continue. When the discharging continues for a time longer than a certain level, the discharging capacity of in - vehicle battery 27 decreases. The first vibration damping process is less restricted in generating vibration damping torque due to the discharging limit of in - vehicle battery 27 compared to the second vibration damping process. Therefore, as described above, even if the discharging capacity of in - vehicle battery 27 decreases due to continuous discharging, the suppression effect of vehicle body vibration is less likely to decrease. Further, when the discharging of in - vehicle battery 27 continues for a preset time T2 or more, the CPU 31 decreases the amplitude of the vibration damping torque generated in the second vibration damping process compared to the case where it does not continue. Therefore, even with the decreased discharging capacity of in - vehicle battery 27 due to continuous discharging, the second vibration damping process can be implemented within an acceptable range.

[0084] (8) When the integrated current of in - vehicle battery 27 is large, the CPU 31 adjusts the amplitude of the vibration damping torque generated in the first vibration damping process to increase and the amplitude of the vibration damping torque generated in the second vibration damping process to decrease, respectively. Therefore, while avoiding overheating of electrical circuit components, the suppression effect of vehicle body vibration can be ensured.

[0085] <Other embodiments> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0086] ·Among the amplitude adjustments of the vibration damping torque based on each of the state of charge SOC, battery temperature THB, charging duration, discharging duration, and integrated current, one or more of them may not be performed. ·For example, in a method other than multiplying the gain, such as addition and subtraction of correction amounts, the amplitude of the vibration damping torque may be adjusted.

[0087] ·The number of cylinders 11 of the engine 10 is not limited to four. ·In the combustion stop process, the combustion of two or more cylinders 11 may be stopped while the combustion of the remaining one or more cylinders 11 is continued.

[0088] ·The combustion stop process may be performed for purposes other than the regeneration of the filter device 15B, for example, to promote the temperature rise of the catalyst device 15A or to suppress vibrations caused by tire unbalance.

[0089] ·It is not essential to provide the torsional damper 19 on the crankshaft 10A. Even when the torsional damper 19 is not provided, torsion occurs in the members mechanically connected to the crankshaft 10A due to the combustion stop of some cylinders. Therefore, even when the torsional damper 19 is not provided, the effect of suppressing vehicle body vibrations can be obtained by performing the first vibration damping process in the above manner.

[0090] ·In the first vibration damping process, similar to the second vibration damping process, the vibration damping torque may be generated so as to increase the torque of the first rotating electrical machine M1 in conjunction with the decrease in the engine torque.

Explanation of Reference Numerals

[0091] 10…Engine 10A…Crankshaft 10B…Engine Mount 11…Cylinder 12…Intake Passage 13… Exhaust passage 14… Throttle valve 15A… Catalytic device 15B… Filter device 16… Injector 17… Ignition device 18… Flywheel 19… Torsional damper 20… Power split mechanism 21… Reduction mechanism 22… Differential mechanism 23… Drive shaft 24… Wheel 25… First inverter 26… Second inverter 27… In-vehicle battery 30… Control device 31… CPU 32… ROM 33… Airflow meter 34… Crank angle sensor 35… Water temperature sensor 36… Output rotational speed sensor 37… Accelerator pedal sensor 38… Battery temperature sensor B… Vehicle body C… Planetary carrier M1… First rotating electric machine M2… Second rotating electric machine R… Ring gear S… Sun gear

Claims

1. A hybrid vehicle having an engine with a plurality of cylinders, a first rotating electrical machine, a second rotating electrical machine, a power split mechanism, and an in-vehicle battery electrically connected to the first rotating electrical machine and the second rotating electrical machine, wherein the engine and the first rotating electrical machine are drivingly connected to a drive shaft of wheels via the power split mechanism, and the second rotating electrical machine is connected to the drive shaft of the wheels without passing through the power split mechanism, and a control device for controlling the hybrid vehicle, a combustion stop process of continuing combustion of the remaining cylinders while stopping combustion of some of the plurality of cylinders, a first vibration damping process of generating vibration damping torque in the first rotating electrical machine to suppress vehicle body vibration accompanying the execution of the combustion stop process, a second vibration damping process of generating vibration damping torque in the second rotating electrical machine to suppress vehicle body vibration accompanying the execution of the combustion stop process, an adjustment process of adjusting to increase the amplitude of the vibration damping torque generated in the second vibration damping process when the engine rotational speed is high, while adjusting to increase the amplitude of the vibration damping torque generated in the first vibration damping process when the engine rotational speed is low, A control device for a hybrid vehicle that performs the above.

2. The control device for a hybrid vehicle according to claim 1, wherein the first vibration damping process is a process of generating the vibration damping torque so that the torque of the first rotating electrical machine decreases at the same period as the period of the torque decrease of the engine due to the combustion stop of the some of the cylinders.

3. The control device for a hybrid vehicle according to claim 2, wherein the adjustment process reduces the amplitude of the vibration damping torque generated in the first vibration damping process when the charge rate of the in-vehicle battery is high compared to when the charge rate is low.

4. The control device for a hybrid vehicle according to claim 3, wherein the adjustment process increases the amplitude of the vibration damping torque generated in the second vibration damping process when the charge rate of the in-vehicle battery is high compared to when the charge rate is low.

5. The control device for a hybrid vehicle according to claim 2, wherein the adjustment process reduces the amplitude of the vibration damping torque generated in the first vibration damping process when the temperature of the in-vehicle battery is low compared to when the temperature is high.

6. The control device for a hybrid vehicle according to claim 5, wherein the adjustment process increases the amplitude of the vibration damping torque generated in the second vibration damping process when the temperature of the in-vehicle battery is low compared to when the temperature is high.

7. The control device for a hybrid vehicle according to claim 2, wherein in the adjustment process, when the charging of the in-vehicle battery continues for a predetermined time or longer, the amplitude of the vibration damping torque generated in the second vibration damping process is made larger than when the charging of the in-vehicle battery does not continue for the predetermined time or longer.

8. The control device for a hybrid vehicle according to claim 2, wherein in the adjustment process, when the discharging of the in-vehicle battery continues for a predetermined time or longer, the amplitude of the vibration damping torque generated in the first vibration damping process is made larger than when the discharging of the in-vehicle battery does not continue for the predetermined time or longer.

9. The control device for a hybrid vehicle according to claim 2, wherein in the adjustment process, when the integrated current of the in-vehicle battery is large, the amplitude of the vibration damping torque generated in the first vibration damping process is adjusted to increase, and the amplitude of the vibration damping torque generated in the second vibration damping process is adjusted to decrease.

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