JP2024033836A - Combustion torque calculation device - Google Patents

Abstract

To accurately calculate torque of a crank shaft.SOLUTION: Targeted for a vehicle 10 including: a front damper 67 located between a crank shaft 21 of an internal combustion engine 20 and an MG rotor 42 of a motor generator 40; a transmission input shaft 51 located between the MG rotor 42 and a driving wheel 70; and a lock-up damper 88 located between the MG rotor 42 and the transmission input shaft 51, a combustion torque calculation device executes processing of: calculating rear stage torsional torque to be applied to the transmission input shaft 51 by the lock-up damper 88 by multiplying a difference between an angular position of the MG rotor 42 and an angular position of the transmission input shaft 51 by a spring constant of the lock-up damper 88; calculating motor torsional torque to be applied to the MG motor 42 by the front damper 67 on the basis of inertia torque of the MG rotor 42 and the rear stage torsional torque; and calculating combustion torque of the crank shaft 21 by adding inertia torque of the crank shaft 21 and the motor torsional torque.SELECTED DRAWING: Figure 1

Description

The present invention relates to a combustion torque calculation device.

The vehicle disclosed in Patent Document 1 includes an internal combustion engine, a damper, and a motor generator. The damper is located on a torque transmission path from the internal combustion engine to the motor generator. In such a configuration, when the torque of the internal combustion engine fluctuates, torsional vibration occurs in the damper. Accordingly, torque caused by torsional vibration is input to the motor generator. At this time, a reaction force caused by inputting torque to the motor generator is input to the internal combustion engine.

The vehicle control device determines a misfire in the internal combustion engine based on changes in rotational fluctuations of the internal combustion engine. At this time, the control device considers the influence of the reaction force included in the rotational fluctuation of the internal combustion engine. Specifically, the control device calculates the reaction force component included in the rotational fluctuation of the internal combustion engine based on the product of the torsion angle of the damper and the spring constant of the damper. Then, the control device makes a misfire determination after eliminating the influence of this reaction force component.

JP2008-248877A

As in Patent Document 1, a predetermined value determined from specifications may be set as the spring constant of the damper for calculating the reaction force component. The actual value of the spring constant of a damper mounted on a vehicle varies within the range of the damper's tolerance. Moreover, as time passes, the characteristics of the damper gradually change and the spring constant changes. For these reasons, in the method of Patent Document 1, variations occur in the spring constant of the damper and thus in the reaction force component, and there is a possibility that the reaction force component cannot be calculated accurately. As a result, there is a possibility that the combustion torque, which is the original torque of the internal combustion engine accompanying combustion of the air-fuel mixture, cannot be accurately calculated.

A combustion torque calculation device for solving the above problem includes an internal combustion engine having a crankshaft, a motor generator located on a torque transmission path from the internal combustion engine to a drive wheel, and having a rotor. a first torsion element capable of transmitting torque between the crankshaft and the rotor; a rear shaft located between the rotor and the drive wheel on the torque transmission path; a second torsional element capable of transmitting torque between the child and the rear shaft; a first sensor for detecting the angular position of the crankshaft; a second sensor for detecting the angular position of the rotor; and a third sensor that detects the angular position of the rear-stage shaft, based on the time-differentiated value of the rotational speed of the crankshaft, where the amount of change in the angular position per unit time is the rotational speed. , a first process of calculating the inertia torque of the crankshaft, a second process of calculating the inertia torque of the rotor based on a time-differentiated value of the rotational speed of the rotor, and an angular position of the rotor. and calculating the rear torsional torque that the second torsion element imparts to the rear shaft by multiplying the difference in the angular position of the rear shaft by the spring constant of the second torsion element. a third process, and a fourth process of calculating a motor torsion torque that the first torsion element applies to the rotor based on the inertia torque of the rotor and the rear torsion torque; A fifth process of calculating combustion torque of the crankshaft by adding the inertia torque of the crankshaft and the motor torsional torque is executed.

In the above vehicle, a reaction force approximately equal to the motor torsional torque acts on the crankshaft. Therefore, the inertia torque of the crankshaft has a value different from the original torque of the internal combustion engine by the amount of this reaction force. Therefore, the combustion torque obtained by adding the motor torsional torque to the inertia torque of the crankshaft can be said to be the torque of the crankshaft in substantially the same state as when no reaction force from the damper is acting on the crankshaft. In order to obtain such torque, in the above configuration, the motor torsional torque is calculated as follows. That is, the motor torsional torque is calculated based on two components: the inertia torque of the rotor and the rear stage torsional torque. In this case, the contribution of the latter stage torsional torque to the total motor torsional torque becomes small. Therefore, even if there is a difference in the subsequent torsional torque due to differences in the product tolerance or aging of the spring constant of the second torsional element, the total value of the motor torsional torque will not change much. . By using such motor torsional torque, the combustion torque of the crankshaft can be calculated accurately.

FIG. 1 is a schematic configuration diagram of a vehicle. FIG. 2 is a block diagram showing the details of the calculation process. FIG. 3 is a diagram showing an example of changes in combustion torque. FIG. 4 is a diagram showing an example of the contribution of each component to the motor torsional torque.

Hereinafter, one embodiment of a combustion torque calculation device will be described with reference to the drawings. As shown in FIG. 1, a hybrid vehicle (hereinafter simply referred to as a vehicle) 10 includes an internal combustion engine 20. As shown in FIG. Internal combustion engine 20 is a driving source for vehicle 10 . A plurality of cylinders 22 are defined in the engine body 20A of the internal combustion engine 20. The number of cylinders 22 is, for example, four. Intake air is introduced into each cylinder 22 through an intake passage 23 in an amount corresponding to the opening degree of the throttle valve 24 . Furthermore, fuel is supplied to each cylinder 22 from a fuel injection valve 25 for each cylinder 22. In each cylinder 22, a mixture of fuel and intake air is ignited by the spark plug 26 of each cylinder 22. Although not shown, each cylinder 22 accommodates a piston. The piston reciprocates within the cylinder 22 in accordance with the combustion of the air-fuel mixture. The crankshaft 21, which is the output shaft of the internal combustion engine 20, rotates in accordance with the movement of the piston. Note that the exhaust gas from each cylinder 22 is exhausted to the outside via an exhaust passage 27.

The crankshaft 21 is connected to a driven shaft 68 via a front damper 67. The front damper 67 is the first torsional element. The front damper 67 is capable of transmitting torque from the crankshaft 21 to the driven shaft 68 or vice versa. Specifically, the front damper 67 attenuates torque fluctuations on one of the crankshaft 21 and the driven shaft 68 and transmits the same to the other. The driven shaft 68 rotates integrally with the crankshaft 21 as the crankshaft 21 rotates.

The driven shaft 68 is connected via the drive clutch 30 to a motor rotating shaft 41 that is the output shaft of the motor generator 40 . The drive clutch 30 is switched between a connected and disconnected state in response to oil pressure from a hydraulic mechanism (not shown). In the connected state, the drive clutch 30 connects the driven shaft 68 and the motor rotating shaft 41. In the disconnected state, the drive clutch 30 separates the driven shaft 68 from the motor rotating shaft 41.

Motor generator 40 is a drive source for vehicle 10. The motor rotation shaft 41 of the motor generator 40 rotates integrally with a rotor (hereinafter referred to as MG rotor) 42, which is a rotor of the motor generator 40. MG rotor 42 is rotatable with respect to stator 43, which is a stator of motor generator 40. Motor generator 40 is electrically connected to battery 48 via inverter 47 . Battery 48 transfers power to and from motor generator 40 . The inverter 47 converts direct current to alternating current.

The motor rotating shaft 41 is connected to an input shaft (hereinafter referred to as a transmission input shaft) 51 of an automatic transmission 55 via a torque converter 80 that is a fluid coupling. The transmission input shaft 51 is a rear stage shaft. A pump impeller 81 of the torque converter 80 rotates integrally with the motor rotating shaft 41. Turbine liner 82 of torque converter 80 rotates together with transmission input shaft 51 . The torque converter 80 is equipped with a lock-up clutch 85. The lock-up clutch 85 is switched between a connected and disconnected state in response to hydraulic pressure from a hydraulic mechanism (not shown). Lockup clutch 85 connects motor rotating shaft 41 and transmission input shaft 51 in a connected state. In the disconnected state, the lock-up clutch 85 disconnects the motor rotating shaft 41 and the transmission input shaft 51. Torque converter 80 also includes a lockup damper 88 that is interposed between motor rotating shaft 41 and transmission input shaft 51 when lockup clutch 85 is engaged. The lockup damper 88 is capable of transmitting torque from the motor rotating shaft 41 to the transmission input shaft 51 or vice versa. Specifically, lockup damper 88 damps torque fluctuations on one of motor rotation shaft 41 and transmission input shaft 51 when lockup clutch 85 is engaged, and transmits the torque fluctuation to the other. Lockup damper 88 is the second torsional element.

The automatic transmission 55 is a stepped transmission in which the gear ratio changes in multiple stages by changing gears. The output shaft 52 of the automatic transmission 55 is connected to left and right drive shafts 59 via a differential 60. Drive shaft 59 is connected to drive wheels 70.

As described above, motor generator 40 is located on the torque transmission path from internal combustion engine 20 to drive wheels 70. A front damper 67 is located between the crankshaft 21 and the MG rotor 42. Furthermore, a transmission input shaft 51 is located between the MG rotor 42 and the drive wheels 70. A lockup damper 88 is located between the transmission input shaft 51 and the MG rotor 42.

Various sensors are attached to the vehicle 10. For example, a first sensor 91, a second sensor 92, and a third sensor 93 are attached to the vehicle 10. The first sensor 91 detects the angular position Ncr of the crankshaft 21. The second sensor 92 detects the angular position Nmg of the MG rotor 42. The third sensor 93 detects the angular position Nat of the transmission input shaft 51. Each of the above sensors detects the angular position of each component within a range of 360 degrees from zero degrees with the same reference position being zero degrees. The reference position is, for example, the 12 o'clock position in a virtual circle centered on the central axis of the component to be detected when each sensor is attached to the vehicle 10. For example, if the central axis of each component is arranged horizontally, the reference position defined above is a position directly above the central axis of each component.

A current sensor 94 that detects a current value A flowing through the motor generator 40 is attached to the vehicle 10. The vehicle 10 is also equipped with an accelerator sensor that detects an accelerator operation amount, which is an operation amount of an accelerator pedal in the vehicle 10, a vehicle speed sensor that detects the traveling speed of the vehicle 10, and the like. The various sensors described above repeatedly transmit signals corresponding to the information detected by themselves to the control device 1, which will be described later.

Vehicle 10 has control device 1 . The control device 1 includes a CPU 2 that is a central processing unit, a memory 3 that stores control programs and data, and the like. Then, the control device 1 executes various processes by causing the CPU 2 to execute programs stored in the memory 3. Note that the control device 1 has a time measurement function.

The control device 1 repeatedly receives detection signals from the various sensors described above. For example, the control device 1 repeatedly receives the angular position Ncr of the crankshaft 21 detected by the first sensor 91. The control device 1 can grasp the rotational state of the crankshaft 21 based on the change in the angular position Ncr of the crankshaft 21. The rotational state of the crankshaft 21 refers to, for example, whether or not the crankshaft 21 is rotating. Similarly to the crankshaft 21, the control device 1 can also grasp the rotational state of the MG rotor 42 and the like based on the detection signals of the second sensor 92 and the third sensor 93.

The control device 1 controls various parts of the vehicle 10. For example, the control device 1 controls the internal combustion engine 20. When controlling the internal combustion engine 20, the control device 1 operates target devices such as a throttle valve 24, a fuel injection valve 25, and a spark plug 26. The control device 1 sequentially combusts the air-fuel mixture in each cylinder 22 by fuel injection from the fuel injection valve 25 and ignition by the spark plug 26 . Further, the control device 1 also controls the motor generator 40 through the operation of the inverter 47, and switches the connected and disconnected states of the drive clutch 30 and the lock-up clutch 85 through the operation of the hydraulic mechanism.

The control device 1 switches the driving mode of the vehicle 10 to a hybrid mode or an electric mode depending on the driving situation of the vehicle 10. In the electric mode, the control device 1 stops driving the internal combustion engine 20, drives the motor generator 40, and disengages the drive clutch 30. On the other hand, in the hybrid mode, the control device 1 drives both the internal combustion engine 20 and the motor generator 40, and connects the drive clutch 30. Note that the control device 1 connects the lock-up clutch 85 in the hybrid mode. For example, the control device 1 selects the electric mode when the accelerator operation amount is relatively small, and selects the hybrid mode when the accelerator operation amount is relatively large. The control device 1 stores in advance a threshold value of the accelerator operation amount for switching between the hybrid mode and the electric mode.

The control device 1 also functions as a calculation device for the combustion torque TY of the crankshaft 21. Here, when the driving mode of the vehicle 10 is the hybrid mode, the torque of the crankshaft 21 is input to the motor rotating shaft 41 via the front damper 67. At this time, when the torque of the crankshaft 21 fluctuates, torsional vibrations occur in the front damper 67, and the torque caused by the torsional vibrations can be input to the motor rotation shaft 41 and, by extension, the MG rotor 42. At this time, a reaction force from the front damper 67 acts on the crankshaft 21. The combustion torque TY is the torque of the crankshaft 21 which theoretically eliminates the reaction force from the front damper 67. That is, the combustion torque TY is the original torque of the crankshaft 21 accompanying combustion of the air-fuel mixture.

The control device 1 is capable of executing calculation processing for calculating the combustion torque TY. The control device 1 repeats the calculation process while the crankshaft 21 continues to rotate. The control device 1 performs the calculation process substantially when the internal combustion engine 20 is being driven, that is, when the hybrid mode is selected as the driving mode of the vehicle 10. For example, the control device 1 executes the calculation process once every time the crankshaft 21 rotates by a specified angle. The prescribed angle is, for example, 30 degrees. The control device 1 determines the start timing of the calculation process based on the change in the angular position Ncr of the crankshaft 21 detected by the first sensor 91.

As shown in FIG. 2, in one calculation process, the control device 1 performs five processes: a first process M1, a second process M2, a third process M3, a fourth process M4, and a fifth process M5. . The control device 1 calculates one combustion torque TY through these five processes.

In the first process M1, the control device 1 calculates the crank inertia torque Tei, which is the inertia torque of the crankshaft 21. Specifically, first, the control device 1 calculates the crank rotation speed ωe, which is the rotation speed of the crankshaft 21. The crank rotation speed ωe is the amount of change in the angular position Ncr of the crankshaft 21 per unit time. The control device 1 calculates the crank rotation speed ωe based on the change in the angular position Ncr of the crankshaft 21 detected by the first sensor 91. For example, the control device 1 calculates the crank rotation speed ωe as follows. First, the control device 1 refers to the length of time from when the first process M1 of the calculation process was executed last time to when the first process M1 of the calculation process is executed this time as the rotation period P. The rotation period P substantially corresponds to the length of time required for the angular position Ncr of the crankshaft 21 to change by a specified angle. The control device 1 calculates the value obtained by dividing the specified angle by this rotation period P as the crank rotation speed ωe. After calculating the crank rotation speed ωe, the control device 1 calculates the crank inertia torque Tei by applying the crank rotation speed ωe to the following (Equation 1). That is, the control device 1 calculates the product of the time differential of the crank rotational speed ωe and the moment of inertia Ie of the crankshaft 21 as the crank inertia torque Tei. The moment of inertia Ie of the crankshaft 21 has a value depending on the mass of the crankshaft 21 and the like. The control device 1 stores the moment of inertia Ie of the crankshaft 21 in advance. The moment of inertia Ie of the crankshaft 21 is calculated in advance, for example, by experiment or simulation.
(Formula 1) Tei=Ie・(dωe/dt)
As described above, in the first process M1, the control device 1 calculates the crank inertia torque Tei based on the time-differentiated value of the crank rotational speed ωe.

In the second process M2, the control device 1 calculates the motor inertia torque Tmgi, which is the inertia torque of the MG rotor 42. Specifically, first, the control device 1 calculates the motor rotation speed ωmg, which is the rotation speed of the MG rotor 42. The motor rotation speed ωmg is the amount of change in the angular position Nmg of the MG rotor 42 per unit time. The control device 1 calculates the motor rotation speed ωmg based on the change in the angular position Nmg of the MG rotor 42 detected by the second sensor 92. For example, the control device 1 calculates the motor rotation speed ωmg as follows. First, the control device 1 refers to the latest value of the angular position Nmg of the MG rotor 42 detected by the second sensor 92 as a specific value. The control device 1 executes the second process M2 of the calculation process this time after previously executing the second process M2 of the calculation process based on this specific value and the value referenced as the specific value when the second process M2 of the calculation process was executed last time. The amount of change in the angular position Nmg of the MG rotor 42 up to this point is calculated. Then, the control device 1 calculates a value obtained by dividing this amount of change by the rotation period P described above as the motor rotation speed ωmg. After calculating the motor rotation speed ωmg, the control device 1 calculates the motor inertia torque Tmgi, which is the inertia torque of the MG rotor 42. The control device 1 calculates the motor inertia torque Tmgi by applying the motor rotation speed ωmg to the following (Equation 2). That is, the control device 1 calculates the product of the time differential of the motor rotation speed ωmg and the moment of inertia Img of the MG rotor 42 as the motor inertia torque Tmgi. The moment of inertia Img of the MG rotor 42 is a value depending on the mass of the MG rotor 42 and the like. The control device 1 stores the moment of inertia Img of the MG rotor 42 in advance. The moment of inertia Img of the MG rotor 42 is calculated in advance through experiment or simulation, for example.
(Formula 2) Tmgi=Img・(dωmg/dt)
As described above, in the second process M2, the control device 1 calculates the motor inertia torque Tmgi based on the time-differentiated value of the motor rotational speed ωmg.

In the third process M3, the control device 1 calculates the rear-stage torsional torque Tr, which is the torque that the lock-up damper 88 applies to the transmission input shaft 51. Here, in the power transmission system, various torque fluctuations may occur on the driving wheel 70 side when viewed from the lockup damper 88. An example of various torque fluctuations is the torque fluctuation that acts on the drive wheels 70 due to frictional resistance on the road surface. The lock-up damper 88 absorbs all the various torque fluctuations that occur on the driving wheel 70 side when viewed from the lock-up damper 88. The rear-stage torsional torque Tr is a value that includes all such torque fluctuations. The control device 1 calculates the rear stage torsional torque Tr as follows. That is, the control device 1 uses the spring constant K1 of the lock-up damper 88 stored in advance, the latest value of the angular position Nmg of the MG rotor 42 detected by the second sensor 92, and the speed change detected by the third sensor 93. The latest value of the angular position Nat of the machine input shaft 51 is referred to. Then, the control device 1 calculates the rear-stage torsional torque Tr by applying those values to (Equation 3). That is, the control device 1 calculates the value obtained by subtracting the angular position Nmg of the MG rotor 42 from the angular position Nat of the transmission input shaft 51 as the angular difference Δθ. Then, the control device 1 calculates a value obtained by multiplying the spring constant K1 of the lock-up damper 88 by this angular difference Δθ as the rear-stage torsional torque Tr. Note that the spring constant K1 of the lock-up damper 88 is calculated in advance, for example, by experiment or simulation.
(Formula 3) Tr=K1・(Nat-Nmg)
In the fourth process M4, the control device 1 calculates the motor torsion torque Tx, which is the torque that the front damper 67 applies to the MG rotor 42. Specifically, as shown in (Equation 4), the control device 1 calculates the motor inertia torque Tmgi calculated in the second process M2, the rear torsion torque Tr calculated in the third process M3, and the motor output torque. By adding Ts, motor torsional torque Tx is calculated. Note that the motor output torque Ts is the torque that the motor generator 40 outputs according to the current value A flowing through the motor generator 40. The control device 1 calculates the motor output torque Ts based on the latest value of the current value A detected by the current sensor 94. Thus, in the fourth process M4, the control device 1 calculates the motor torsional torque Tx based on the motor inertia torque Tmgi and the rear stage torsional torque Tr.
(Formula 4) Tx=Tmgi+Tr+Ts
In the fifth process M5, the control device 1 calculates the combustion torque TY. Specifically, the control device 1 adds the crank inertia torque Tei calculated in the first process M1 and the motor torsion torque Tx calculated in the fourth process M4, as shown in (Equation 5). The obtained value is calculated as combustion torque TY.
(Formula 5) TY=Tei+Tx
As described above, the crank inertia torque Tei includes the reaction force that the crankshaft 21 receives from the front damper 67. As described above, this reaction force is a force that acts from the front damper 67 on the crankshaft 21 when the front damper 67 applies it to the motor generator 40 due to the torsional vibration of the front damper 67. This reaction force has the same absolute value as the motor torsional torque Tx, but has an opposite sign. Therefore, by adding the motor torsional torque Tx to the crank inertia torque Tei, it is theoretically possible to obtain the torque of the crankshaft 21 that eliminates the force acting on the crankshaft 21 from the front damper 67.

The control device 1 is capable of executing misfire determination processing. The control device 1 continues to perform the misfire determination process while the crankshaft 21 continues to rotate. In the misfire determination process, the control device 1 monitors the combustion torque TY calculated in the calculation process over time. As shown in the first period H1 in FIG. 3, when the combustion of the air-fuel mixture is repeated stably, the combustion torque TY repeats increases and decreases according to the combustion of the air-fuel mixture in each cylinder 22. That is, the combustion torque TY increases once as the mixture is burned in one cylinder 22, and then decreases when the combustion of the mixture ends. The combustion torque TY repeats such a cycle of increase and decrease. On the other hand, when a misfire occurs in a certain cylinder 22, the combustion torque TY shows a sudden drop, as shown in the second period H2 in FIG. The control device 1 stores in advance the maximum value of the combustion torque TY at which it can be considered that a drop in the combustion torque TY due to a misfire has occurred as a misfire determination value TY1. The misfire determination value TY1 is determined in advance through experiment or simulation, for example. In the misfire determination process, the control device 1 determines whether or not there is a misfire in the internal combustion engine 20 based on the misfire determination value TY1. That is, the control device 1 determines that a misfire has occurred when the combustion torque TY becomes equal to or less than the misfire determination value TY1, and otherwise determines that a misfire has not occurred. In this way, in the misfire determination process, the control device 1 determines whether or not there is a misfire in the internal combustion engine 20 based on the combustion torque TY calculated in the calculation process.

The operation and effects of this embodiment will be explained. In this embodiment, when calculating the combustion torque TY, which is the original torque of the crankshaft 21 accompanying combustion of the air-fuel mixture, the motor torsion torque Tx acting on the crankshaft 21 is calculated as shown in the above (Equation 5). Consider. In this embodiment, in calculating this motor torsional torque Tx, as shown in the above (Equation 4), three components are used: motor inertia torque Tmgi, rear stage torsional torque Tr, and motor output torque Ts. Use. Now, as a comparative example when the motor torsional torque Tx is calculated from three components as in this embodiment, as shown in FIG. 4, the motor torsional torque TxA is calculated using only one specific component Ta. Consider the manner of calculation. The specific component Ta is the product of the spring constant K2 of the front damper 67 and the specific angle difference. Note that the spring constant K2 is a value that is predetermined as a fixed value determined from specifications. The specific angular difference is the difference between the angular position Nmg of the MG rotor 42 and the angular position Ncr of the crankshaft 21. When the motor torsional torque TxA is calculated using only one specific component Ta as in this comparative example, the calculation accuracy of the motor torsional torque TxA is determined only by the calculation accuracy of the specific component Ta. From this, in order to ensure the calculation accuracy of the motor torsional torque TxA, high accuracy is required for the specific component Ta. This means that high accuracy is also required for the spring constant K2, which is one element of the specific component Ta. As mentioned above, the spring constant K2 is a predetermined fixed value. However, the actual value of this spring constant K2 may vary due to differences in product tolerances and aging. Therefore, due to the difference between the actual value and the fixed value regarding the spring constant K2, the motor torsional torque TxA calculated in the comparative example is a value that deviates greatly from the motor torsional torque TxA that should originally be calculated. It can be.

On the other hand, when calculating the motor torsional torque Tx from three components as in the present embodiment, as shown in the example of FIG. The contribution of each becomes smaller. Note that the contribution ratios of the three components shown in FIG. 4 are just an example, and do not necessarily match the actual ones. Here, the rear-stage torsional torque Tr, which is one of the above three components, includes the spring constant K1 of the lockup damper 88, as shown in the above (Equation 3). This spring constant K1, like the spring constant K2 of the above-mentioned comparative example, can change depending on differences in product tolerance and aging. However, in this embodiment, since the motor torsional torque Tx is dispersed into three components, the contribution of the spring constant K1 in calculating the motor torsional torque Tx becomes small. Therefore, even if the spring constant K1 of the lock-up damper 88 has product tolerances or deterioration over time, the combustion torque TY can be calculated with high accuracy. Then, by performing the misfire determination process using this accurate combustion torque TY, it is possible to accurately determine whether or not there is a misfire in the internal combustion engine 20. Note that when calculating the motor torsional torque Tx in the mode of this embodiment, the only additional equipment required is the third sensor 93 compared to the case of calculating the motor torsional torque Tx in the mode of the comparative example. be. Therefore, in the aspect of this embodiment, the number of parts can also be minimized.

Note that the above embodiment can be modified and implemented as follows. The above embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.

- The manner of misfire determination is not limited to the example of the above embodiment. The manner of misfire determination is not limited as long as misfire determination can be performed appropriately. The misfire determination may be made based on the combustion torque TY.

- The use of combustion torque TY is not limited to misfire determination. It is effective to use the combustion torque TY in cases such as diagnosis that requires the use of the original torque of the crankshaft 21.

- The overall configuration of the vehicle 10 is not limited to the example of the embodiment described above. It is not essential that the vehicle 10 has the torque converter 80 and thus the lock-up damper 88. If the vehicle 10 does not have a lock-up damper 88, other components may be employed as the second torsional element. If the vehicle 10 does not have the lock-up damper 88, an axial component such as a shaft may be treated as the second torsional element. Even a shaft-shaped component can function in a manner similar to a damper due to twisting. The second torsion element may be any part located between the motor generator 40 and the rear shaft. Furthermore, it is possible that the components of the rear-stage shaft are other than the transmission input shaft 51. When changing the rear stage shaft from the transmission input shaft 51, the target component whose angular position is detected by the third sensor 93 may be changed.

- When changing the second torsional element from the lock-up damper 88 as in the above modification example, the spring constant used to calculate the rear-stage torsional torque Tr is adopted as the second torsional element. Just change it to the spring constant of the part. In addition, when changing the rear stage shaft from the transmission input shaft 51, when calculating the rear stage torsional torque Tr, the difference between the angular position of the part adopted as the rear stage shaft and the angular position Nmg of the MG rotor 42 is calculated as follows. It is sufficient to multiply the spring constants of the two torsional elements. In this way, the content of the calculation process can be changed according to the configuration of the vehicle 10 and the like.

DESCRIPTION OF SYMBOLS 10...Vehicle, 20...Internal combustion engine, 21...Crankshaft, 40...Motor generator, 42...MG rotor, 67...Front damper, 51...Transmission input shaft, 70...Drive wheel, 80...Torque converter, 85...Lockup Clutch, 88... Lockup damper, 91... First sensor, 92... Second sensor, 93... Third sensor.

Claims (3)

an internal combustion engine having a crankshaft;
a motor generator located on a torque transmission path from the internal combustion engine to drive wheels and having a rotor;
a first torsional element capable of transmitting torque between the crankshaft and the rotor;
a rear shaft located between the rotor and the drive wheel on the torque transmission path;
a second torsion element capable of transmitting torque between the rotor and the rear shaft;
a first sensor that detects the angular position of the crankshaft;
a second sensor that detects the angular position of the rotor;
a third sensor that detects the angular position of the rear shaft;
Targeting vehicles with
When the rotational speed is the amount of change in angular position per unit time,
a first process of calculating inertia torque of the crankshaft based on a value obtained by time-differentiating the rotational speed of the crankshaft;
a second process of calculating the inertia torque of the rotor based on a time-differentiated value of the rotation speed of the rotor;
By multiplying the difference between the angular position of the rotor and the angular position of the rear shaft by the spring constant of the second torsion element, the second torsion element imparts to the rear shaft. a third process of calculating the twisting torque;
a fourth process of calculating a motor torsion torque that the first torsion element applies to the rotor based on the inertia torque of the rotor and the rear-stage torsion torque;
a fifth process of adding the inertia torque of the crankshaft and the motor torsion torque to calculate the combustion torque of the crankshaft;
A device for calculating combustion torque. The combustion torque calculation device according to claim 1, wherein the presence or absence of a misfire in the internal combustion engine is determined based on the combustion torque. The vehicle includes a torque converter located between the rotor and the rear shaft,
The torque converter includes a lock-up clutch that switches between a connected state in which the rotor and the rear-stage shaft are connected, or a disconnected state in which the rotor and the rear-stage shaft are disconnected, and a lock-up clutch that switches to a disconnected state in which the rotor and the rear-stage shaft are disconnected; and a lock-up damper interposed between the rear shaft,
The combustion torque calculation device according to claim 1 or 2, wherein the second torsional element is the lockup damper.

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