JP7666352B2 - Control device - Google Patents

Description

The present invention relates to a control device.

For example, Patent Document 1 describes a vehicle in which the output torque of the engine is transmitted to the drive wheels via a motor generator, in which a main ECU (Electronic Control Unit) controls the engagement of the clutch between the engine and the motor generator.

JP 2021-54165 A

When clutch engagement processing is distributed and executed across multiple computers such as ECUs, the processing load on each computer can be reduced compared to when it is executed by only one computer. For example, one computer calculates control values related to the engagement state, such as hydraulic command values, and another computer receives the control values from that computer and uses them to control clutch engagement.

However, if a communication failure between computers makes it impossible to send and receive control values, for example, it becomes impossible to control the engagement of the clutch. If the clutch is disengaged, the engine's output torque cannot be transmitted to the drive wheels via the motor generator, making it impossible for the engine to drive the vehicle. This problem also exists with internal combustion engines other than engines, and rotating electric machines other than motor generators.

The present invention was made in consideration of the above problems, and aims to provide a control device that can run a vehicle using an internal combustion engine even if a communication failure occurs between computers.

The control device of the present invention is a control device for a vehicle in which the output torque of an internal combustion engine is transmitted to driving wheels via a rotating electric machine , and has a first computer that controls engagement of the clutch based on a control value related to a clutch that engages the shafts of the internal combustion engine and the rotating electric machine when the internal combustion engine is cranked by a starter, and a second computer that calculates the control value according to the rotational speeds of the internal combustion engine and the rotating electric machine and transmits the control value to the first computer, wherein the second computer calculates the control value so that the clutch is engaged when the difference between the rotational speeds of the internal combustion engine and the rotating electric machine becomes equal to or less than a predetermined value, and when the first computer is unable to receive the control value from the second computer, the first computer determines the control value so that the clutch is engaged at a predetermined timing before the difference between the rotational speeds of the internal combustion engine and the rotating electric machine becomes equal to or less than the predetermined value .

According to the present invention, even if a communication failure occurs between computers, the vehicle can be driven by the internal combustion engine.

FIG. 1 is a configuration diagram showing an example of a hybrid vehicle system. 4 is a flowchart showing an example of an engine start process of a vehicle control device. 4 is a flowchart showing an example of an operation of an ECT (Electronic Control Transmission)-ECU in clutch engagement processing. 5 is a flowchart showing an example of an operation of an EFI (Electrical Fuel Injection)-ECU in a clutch engagement process. 4 is a time chart showing an example of clutch engagement control during starter startup. 5 is a time chart showing an example of clutch engagement control during startup of the motor generator. 4 is a time chart showing an example of clutch engagement control when starting an engine while an EV (Electric Vehicle) is running.

(Configuration of Hybrid Vehicle System)
1 is a configuration diagram showing an example of a hybrid vehicle system 9. The hybrid vehicle system 9 is mounted on, for example, a hybrid vehicle, and includes a vehicle control device 1, an engine 2, a clutch 3, a motor generator (MG) 4, a starter 21, a gear device 22, a crank angle sensor 23, a hydraulic system Sa, an MG drive system Sb, a torque converter (T/C) 52, an automatic transmission (A/T) 53, and drive wheels 54. The hybrid vehicle is an example of a vehicle.

The crankshaft 20 of the engine 2 is connected to the drive shaft 40 of the MG4 via the clutch 3. The drive shaft 40 of the MG4 is further connected to a torque converter 52, and the output shaft 50 of the torque converter 52 is connected to an automatic transmission 53. The output shaft 51 of the automatic transmission 53 is connected to the drive wheels 54 via a differential gear (not shown) or the like.

Engine 2 is an example of an internal combustion engine. Engine 2 compresses and ignites a mixture of gasoline and air supplied to the combustion chamber, causing pistons in cylinders to reciprocate, thereby rotating crankshaft 20. Crankshaft 20 is connected to starter 21 via gear device 22. Starter 21 is a motor that assists in starting engine 2. As the rotating shaft of starter 21 is connected to gear device 22, crankshaft 20 rotates in conjunction with the rotation of starter 21. Crank angle sensor 23 detects the angle of crankshaft 20 and outputs it to vehicle control device 1.

The clutch 3 switches the crankshaft 20 and the drive shaft 40 between an engaged state and a disengaged state. The clutch 3 engages or disengages the clutch plates on the crankshaft 20 side and the clutch plates on the drive shaft 40 side according to the hydraulic pressure controlled by the hydraulic system Sa. When the clutch 3 engages the crankshaft 20 and the drive shaft 40, the output torque of the engine 2 is transmitted to the drive wheels 54 via the MG4.

The hydraulic system Sa has an electric oil pump 30, a mechanical oil pump 31, a line pressure solenoid valve 32, a switch solenoid valve 33, and a linear solenoid valve 34. The electric oil pump 30 and the mechanical oil pump 31 operate to apply hydraulic pressure to the line pressure solenoid valve 32. The electric oil pump 30 is driven by the vehicle control device 1. The mechanical oil pump 31 is mechanically connected to the drive shaft 40 of the MG4, and is driven by the rotation of the drive shaft 40. In addition, the line pressure solenoid valve 32, the switch solenoid valve 33, and the linear solenoid valve 34 are driven by the vehicle control device.

The line pressure solenoid valve 32 generates a substantially constant line pressure from the hydraulic pressure applied from at least one of the electric oil pump 30 and the mechanical oil pump 31. The line pressure is applied from the line pressure solenoid valve 32 to the switch solenoid valve 33. The switch solenoid valve 33 switches the supply destination of the line pressure to either the linear solenoid valve 34 or the clutch 3.

When line pressure is supplied from the switch solenoid valve 33, the linear solenoid valve 34 generates hydraulic pressure from the line pressure according to the opening degree and supplies it to the clutch 3. The clutch 3 changes the degree of engagement according to the line pressure supplied from the switch solenoid valve 33 or the hydraulic pressure supplied from the linear solenoid valve 34.

The line pressure is also supplied to the hydraulic circuit in the automatic transmission 53. The automatic transmission 53 uses hydraulic pressure to change gears.

The MG drive system Sb also has a battery 41, a system main relay (SMR) 42, a boost converter 43, an inverter 45, a current sensor 46, and a rotation speed sensor 47. The battery 41 is, for example, a lithium-ion battery, and supplies power to the MG4. The SMR 42 is connected between the battery 41 and the boost converter 43. The SMR 42 is turned on and off by the vehicle control device 1. When the SMR 42 is in the on state, power is supplied to the MG4, and when the SMR 42 is in the off state, power is not supplied to the MG4.

The boost converter 43 boosts the power supply voltage applied from the battery 41 and applies it to the inverter 45. The inverter 45 converts the DC current of the battery 41 into a three-phase AC current by switching a plurality of switch elements, and supplies it to the MG4. The inverter 45 generates currents of the u-phase, v-phase, and w-phase. Note that examples of the switch elements include, but are not limited to, IGBTs (Insulated Gate Bipolar Transistors).

MG4 is an example of a rotating electric machine. MG4 functions as both a generator and a motor. When operating as a motor, MG4 is driven by three-phase AC current flowing from inverter 45 to the three-phase windings. MG4 is equipped with a rotor and a stator (not shown), and the rotor rotates due to a rotating magnetic field generated from the stator by the three-phase AC current. Drive shaft 40 is provided at the center of the rotor.

The rotation speed sensor 47 detects the number of rotations per unit time (rotational speed) of the drive shaft 40 of the MG4. The rotation speed sensor 47 may detect the rotation speed from, for example, a detection value (rotor position) of a resolver. The current sensor 46 detects each current value of the three-phase AC current output from the inverter 45. The rotation speed sensor 47 and the current sensor 46 output each detection value to the vehicle control device 1.

The hybrid vehicle system 9 also has an accelerator opening sensor 90, an ignition switch 91, and a multi-information display (hereinafter referred to as display) 92. The accelerator opening sensor 90 detects the opening of an accelerator pedal (not shown) of the hybrid vehicle and outputs it to the vehicle control device 1. The ignition switch 91 is used to start the hybrid vehicle.

The display 92 displays various information related to the state of the hybrid vehicle based on the information signal input from the vehicle control device 1. For example, the display 92 displays Ready On, which indicates that the hybrid vehicle is ready to run, and Ready Off, which indicates that the hybrid vehicle is not ready to run.

The vehicle control device 1 has an EFI-ECU 11, a MG (Motor Generator)-ECU 12, and an ECT-ECU 13, which are connected to each other via a communication bus 10. The EFI-ECU 11, MG-ECU 12, and ECT-ECU 13 each include a processor such as a CPU (Central Processing Unit) and memories such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and operate by the CPU performing various types of arithmetic processing according to programs read from the memory. The EFI-ECU 11, MG-ECU 12, and ECT-ECU 13 communicate with each other via the communication bus 10 according to a communication method such as a CAN (Controller Area Network).

The EFI-ECU 11 controls the engine 2, the starter 21, the hydraulic system Sa, and the display 92. The EFI-ECU 11 also receives the detection values of the crank angle sensor 23 and the accelerator opening sensor 90, as well as a switch signal from an ignition switch 91.

When the EFI-ECU 11 receives a switch signal indicating that the ignition switch 91 has been pressed, it cranks and starts the engine 2. There are two ways to start the engine 2: starter start, which uses the starter 21 for cranking, and MG start, which uses the MG4 for cranking. Furthermore, while the hybrid vehicle is running on the MG4, it is also possible to start the engine 2 using the rotation of the drive shaft 40. The EFI-ECU 11 selects between these cranking means depending on, for example, the remaining amount of fuel or the remaining amount of the battery 41.

When starting the starter, the EFI-ECU 11 activates the starter 21 to start the rotation of the crankshaft 20. The EFI-ECU 11 controls the clutch 3 to an engaged state according to the rotation speed of the crankshaft 20. As a result, the crankshaft 20 engages with the drive shaft 40 of the MG4, and the crankshaft 20 and drive shaft 40 rotate together as a single unit.

When starting the MG, the EFI-ECU 11 controls the clutch 3 to be in an engaged state. After that, the EFI-ECU 11 instructs the MG-ECU 12 to start the MG 4. When the drive shaft 40 starts to rotate due to the start of the MG 4, the crankshaft 20 also starts to rotate together with the drive shaft 40.

When the rotation speed of the crankshaft 20 increases and the engine 2 becomes capable of rotating autonomously, the engine 2 enters a state of full combustion. At this time, the EFI-ECU 11 determines that the engine 2 has started and that the hybrid vehicle is in a state in which it is possible to run, and displays Ready On on the display 92.

When Ready is on, the EFI-ECU 11 controls the engine 2 based on the detection values of various sensors, such as the crank angle sensor 23, in accordance with the user's operation. For example, the EFI-ECU 11 calculates a command value for the output torque required of the engine 2 from the detection values of various sensors, such as the accelerator opening sensor 90, and controls the intake amount and ignition timing of the engine 2 according to the command value for the output torque.

The MG-ECU 12 controls the MG drive system Sb. The MG-ECU 12 turns on the SMR 42 and performs switching control of the inverter 45 according to the command value of the output torque of the MG4. At this time, the MG-ECU 12 acquires various detection values from the rotation speed sensor 47, current sensor 46, etc., and generates a switching signal for the inverter 45 based on each detection value. As a result, three-phase AC current is supplied from the inverter 45 to the MG4, and the MG4 outputs an output torque.

The EFI-ECU 11 normally drives the hybrid vehicle using the engine 2 and MG4. This mode of driving is referred to as EHV (Electric Hybrid Vehicle) driving. In EHV driving, the EFI-ECU 11 calculates command values for the output torque of the engine 2 and MG4 based on various detection values from the accelerator position sensor 90 and the like in order to distribute the output torque required for driving to the engine 2 and MG4. The EFI-ECU 11 transmits the command value for the output torque of the MG4 to the MG-ECU 12.

Depending on the state of the hybrid vehicle, the EFI-ECU 11 also stops the engine 2 and runs the hybrid vehicle using only the output torque of the MG4. This mode of running is referred to as EV (Electric Vehicle) running. In EV running, the EFI-ECU 11 allocates the output torque required for running only to the MG4, calculates a command value, and sends it to the MG-ECU 12.

During EV driving, for example, if the remaining charge of the battery 41 falls below a predetermined level, the EFI-ECU 11 switches the driving mode to EHV driving. Since the clutch 3 is in a disengaged state during EV driving to reduce the load on the MG4, the EFI-ECU 11 controls the clutch 3 to an engaged state when switching the driving mode to EHV driving.

The EFI-ECU 11 is an example of a first computer. When the engine 2 starts, the EFI-ECU 11 controls the engagement of the clutch 3 based on a hydraulic command value and a line pressure switching value so that the output torque of the engine 2 is transmitted to the drive wheels 54 via the MG 4. At this time, the EFI-ECU 11 receives the hydraulic command value and the line pressure switching value from the ECT-ECU 13 via the communication bus 10. The hydraulic command value is an example of a control value related to the engagement state of the clutch 3.

The ECT-ECU 13 is an example of a second computer. The ECT-ECU 13 determines a line pressure switching value according to the starting mode of the engine 2, calculates a hydraulic command value according to the rotation speeds of the engine 2 and the MG4, and transmits it to the EFI-ECU 11. At this time, the ECT-ECU 13 receives starting information including information on the starting mode of the engine 2 and the rotation speeds of the engine 2 and the MG4 from the EFI-ECU 11 via the communication bus 10. Here, the information on the starting mode of the engine 2 indicates any one of starter starting by the starter, MG starting by the MG4, and starting during EV driving. The ECT-ECU 13 also controls the automatic transmission 53 according to the line pressure. The ECT-ECU 13 also drives the electric oil pump 30.

The EFI-ECU 11 controls the switch solenoid valve 33 based on the line pressure switching value, and controls the linear solenoid valve 34 based on the hydraulic command value. When the line pressure switching value is "0", the switch solenoid valve 33 supplies the line pressure to the clutch 3, and when the line pressure switching value is "1", the switch solenoid valve 33 supplies the line pressure to the linear solenoid valve 34. The linear solenoid valve 34 generates hydraulic pressure from the line pressure according to the hydraulic command value and supplies it to the clutch 3. The higher the hydraulic pressure supplied to the clutch 3, the higher the degree of engagement of the clutch 3.

The EFI-ECU 11 monitors for communication failures with the ECT-ECU 13. For example, the EFI-ECU 11 detects a communication failure when it receives notification of the occurrence of a malfunction from the ECT-ECU 13, or when it fails to receive the line pressure switching value and hydraulic command value from the ECT-ECU 13 a predetermined number of times in succession. When a communication failure occurs, the EFI-ECU 11 is unable to receive the line pressure switching value and hydraulic command value from the ECT-ECU 13.

In this case, the EFI-ECU 11 determines the line pressure switching value and the hydraulic command value instead of the ECT-ECU 13. The EFI-ECU 11 determines the line pressure switching value according to the starting mode of the engine 2, and determines the hydraulic command value according to a predetermined pattern according to the starting mode of the engine 2.

As a result, the EFI-ECU 11 can control the engagement of the clutch 3 based on the hydraulic command value that it determines itself, without requiring the ECT-ECU 13 to perform calculation processing of the hydraulic command value. Furthermore, the EFI-ECU 11 determines the line pressure switching value instead of the ECT-ECU 13, and controls the engagement of the clutch 3. As a result, the output torque of the engine 2 is transmitted to the drive shaft 40 of the MG 4 via the clutch 3. This allows the vehicle control device 1 to run the hybrid vehicle using the engine 2 even if a communication failure occurs between the EFI-ECU 11 and the ECT-ECU 13.

If the above communication failure occurs, it is possible that the ECT-ECU 13 will malfunction and be unable to drive the electric oil pump 30. In this case, the electric oil pump 30 will not operate and will be unable to supply line pressure. However, even if the electric oil pump 30 cannot operate, if the MG4 starts up and the drive shaft 40 rotates, the mechanical oil pump 31 will operate and be able to supply line pressure.

(Engine Start Processing of Vehicle Control Device)
2 is a flowchart showing an example of an engine start process of the vehicle control device 1. This process is executed, for example, periodically.

First, the EFI-ECU 11 determines whether the hybrid vehicle is in a Ready-Off state (step St1). If the hybrid vehicle is parked, the vehicle is in a Ready-Off state.

If the driving status is Ready-Off (Yes in step St1), the EFI-ECU 11 determines whether the ignition switch (IG-SW) 91 is turned on (step St2). If the ignition switch 91 is off (No in step St2), the process of step St2 is executed again.

When the ignition switch 91 is on (Yes in step St2), the EFI-ECU 11 determines whether the engine 2 should be started by starter start or MG start (step St3). When the engine 2 should be started by starter start (Yes in step St3), the EFI-ECU 11 starts the starter 21 (step St4). As a result, the driving force of the starter 21 is transmitted to the crankshaft 20 via the gear device 22, and the crankshaft 20 starts to rotate.

Next, the EFI-ECU 11 starts controlling the engine 2 according to a predetermined starting pattern (step St5). Next, the EFI-ECU 11 controls the hydraulic system Sa to engage the clutch 3 (step St6). This causes the crankshaft 20 and the drive shaft 40 to engage with each other, so that the output torque of the engine 2 is input to the MG4 and transmitted to the drive wheels 54.

When the MG is started (No in step St3), the EFI-ECU 11 controls the hydraulic system Sa to engage the clutch 3 (step St8). This causes the crankshaft 20 and the drive shaft 40 to engage with each other, allowing the driving force of the MG 4 to be transmitted to the crankshaft 20.

Next, the EFI-ECU 11 instructs the MG-ECU 12 to start the MG 4 (step St9). This causes the drive shaft 40 to start rotating. Next, the EFI-ECU 11 starts controlling the engine 2 according to a predetermined starting pattern (step St10).

Next, the EFI-ECU 11 updates the driving status to Ready ON (step St7). At this time, the EFI-ECU 11 sets the driving status to Ready ON when various conditions, such as the rotation speed of the crankshaft 20, are satisfied. The EFI-ECU 11 displays Ready ON on the display 92.

If the driving status is Ready ON (No in step St1), the EFI-ECU 11 determines whether the hybrid vehicle is in EV driving mode (step St11). If the hybrid vehicle is in EHV driving mode (No in step St11), the engine 2 has already started, and this process ends.

When the vehicle is in EV driving mode (Yes in step St11), the EFI-ECU 11 controls the hydraulic system Sa to engage the clutch 3 in order to start the engine 2 (step St12). This causes the crankshaft 20 and the drive shaft 40 to engage with each other, allowing the driving force of the MG4 to be transmitted to the crankshaft 20.

Next, the EFI-ECU 11 starts controlling the engine 2 according to a predetermined starting pattern (step St13). This allows the output torque of the engine 2 to be transmitted to the drive wheels 54 via the clutch 3 and the drive shaft 40, enabling the hybrid vehicle to run in EHV mode. This allows the hybrid vehicle to run a longer distance than in EV mode.

(Clutch engagement process)
3 is a flowchart showing an example of the operation of the ECT-ECU 13 in the process of engaging the clutch 3. This operation is executed in the above steps St6, St8, and St12.

First, the ECT-ECU 13 determines whether or not engine 2 start information has been received from the EFI-ECU 11 (step St20). The start information includes information on the start mode of the engine 2 and the rotation speeds of the engine 2 and the MG4. If start information has not been received (No in step St20), the process of step St20 is executed again.

If start information has been received (Yes in step St20), the ECT-ECU 13 determines the line pressure switching value according to the start mode of the engine 2 (step St21). Next, the ECT-ECU 13 calculates the hydraulic command value according to the rotation speeds of the engine 2 and the MG4 (step St22).

Next, the ECT-ECU 13 transmits the line pressure switching value and the hydraulic pressure command value to the EFI-ECU 11 via the communication bus 10 (step St23). At this time, the ECT-ECU 13 inserts the line pressure switching value and the hydraulic pressure command value into a predetermined position of the control signal that is transmitted, for example, periodically via the communication bus 10.

The ECT-ECU 13 then determines whether or not the engagement of the clutch 3 has been completed based on the engagement state information of the clutch 3 acquired from, for example, the EFI-ECU 11 (step St24). If the engagement of the clutch 3 has not been completed (No in step St24), the process of step St20 is executed again. If the engagement of the clutch 3 has been completed (Yes in step St24), this process ends. This is how the ECT-ECU 13 operates.

4 is a flowchart showing an example of the operation of the EFI-ECU 11 in the process of engaging the clutch 3. This operation is executed in the above steps St6, St8, and St12.
First, the EFI-ECU 11 transmits start information of the engine 2 to the ECT-ECU 13 via the communication bus 10 (step St30). At this time, the EFI-ECU 11 calculates the rotation speed of the engine 2 from the detection value of the crank angle sensor 23, and obtains the rotation speed of the MG4 from the rotation speed sensor 47.

Next, the EFI-ECU 11 determines whether the line pressure switching value and hydraulic command value have been normally received from the ECT-ECU 13 via the communication bus 10 (step St31). At this time, if the EFI-ECU 11 is unable to obtain a normal line pressure switching value and hydraulic command value from the control signal input from the communication bus 10 within a predetermined time, for example, it determines that reception has failed.

When the EFI-ECU 11 receives a normal line pressure switching value and hydraulic command value (Yes in step St31), it controls the hydraulic system Sa based on the line pressure switching value and hydraulic command value (step St32). Next, the EFI-ECU 11 determines whether or not the engagement of the clutch 3 is complete (step St33). At this time, the EFI-ECU 11 determines the completion of the engagement by, for example, detecting the hydraulic pressure supplied to the clutch 3 with a sensor or the like.

If the engagement of the clutch 3 is incomplete (No in step St33), the processes from step St30 onwards are executed again. If the engagement of the clutch 3 is complete (Yes in step St33), this process ends.

If the EFI-ECU 11 has not received a normal line pressure switching value and hydraulic pressure command value (No in step St31), it determines that reception has failed and judges whether a failure has occurred in communication with the ECT-ECU 13 (step St34). At this time, the EFI-ECU 11 may, for example, determine the presence or absence of a failure based on the number of times reception has failed, but is not limited to this.

If no failure has occurred (No in step St34), the processes from step St30 onwards are executed again.

If a fault has occurred (Yes in step St34), the EFI-ECU 11 determines a line pressure switching value and a hydraulic command value (step St35). At this time, the EFI-ECU 11 calculates the hydraulic command value according to a predetermined pattern that brings the clutch 3 into an engaged state, in order to eliminate the need for calculation processing similar to that of the ECT-ECU 13. The EFI-ECU 11 also determines the line pressure switching value according to the starting mode of the engine 2. In the case of MG start, the EFI-ECU 11 sets the line pressure switching value to 0 in order to bring the clutch 3 into engagement by the line pressure. Next, the EFI-ECU 11 controls the hydraulic system Sa based on the line pressure switching value and the hydraulic command value (step St36).

The EFI-ECU 11 then determines whether or not the clutch 3 has been engaged (step St37). If the clutch 3 has not been engaged (No in step St37), the processes from step St35 onwards are executed again. If the clutch 3 has been engaged (Yes in step St37), this process ends. The EFI-ECU 11 operates in this manner.

As described above, when the EFI-ECU 11 is unable to receive the line pressure switching value and the hydraulic command value from the ECT-ECU 13, the EFI-ECU 11 determines the line pressure switching value and the hydraulic command value instead of the ECT-ECU 13. Therefore, even if a failure occurs in communication with the ECT-ECU 13, the EFI-ECU 11 can engage the clutch 3 based on the line pressure switching value and the hydraulic command value to run the hybrid vehicle using the output torque of the engine 2.

(Example of clutch engagement control)
Next, an example of engagement control of the clutch 3 in the event of a communication failure in the ECT-ECU 13 will be described with reference to Figures 5 to 7. In Figures 5 to 7, the starter state indicates whether the starter 21 is activated or stopped. The engine speed indicates the number of revolutions (rpm) of the crankshaft 20 per unit time, and the MG speed indicates the number of revolutions (rpm) of the drive shaft 40 per unit time. The number of revolutions of the drive shaft 40 can be obtained, for example, from the detection value of the crank angle sensor 23. The MG torque indicates the output torque of the MG 4.

Figure 5 is a time chart showing an example of clutch 3 engagement control during starter starting. In this example, the vehicle control device 1 starts the engine 2 using the starter 21 to launch the hybrid vehicle.

At time T0, the EFI-ECU 11 starts the starter 21, which is currently stopped. This causes the engine 2 rotation speed to increase from 0 to a constant value Ri. At time T1, the EFI-ECU 11 controls the intake amount and ignition timing of the engine 2 according to an output torque command value that follows a predetermined starting pattern. This causes the engine 2 rotation speed to increase from the constant value Ri to the rotation speed Rn, which is a necessary condition for Ready on. During this increase, the EFI-ECU 11 stops the starter 21.

After that, at time T3, the EFI-ECU 11 instructs the MG-ECU 12 to start up MG4. The output torque of MG4 becomes a constant value during the period from time T3 to T4, and the rotation speed of MG4 starts to increase.

At time T2, which is before time T3 when MG4 is started, the EFI-ECU 11 starts engaging the clutch 3. The EFI-ECU 11 controls the line pressure switching value to 1, and supplies the line pressure to the linear solenoid valve 34. The EFI-ECU 11 also controls the hydraulic pressure supplied to the clutch 3 from the linear solenoid valve 34 by controlling the hydraulic pressure command value according to a predetermined start-up pattern.

At time T2, the EFI-ECU 11 increases the hydraulic command value to Pa, and then decreases it to a predetermined value. Next, at time Ta, the EFI-ECU 11 increases the hydraulic command value from the predetermined value to Pb, and after the predetermined time has elapsed, gradually increases it to Pc. As a result, engagement is completed at time T5, and the rotation speed of the MG4 matches the rotation speed (Rn) of the engine 2. Note that the EFI-ECU 11 controls the line pressure switch value to 0 at time T5.

The dotted line portion of the hydraulic command value here is the value when no communication failure of the ECT-ECU 13 occurs. In this case, the ECT-ECU 13 calculates the hydraulic command value from the rotation speeds of the engine 2 and MG4 from time T2 to Ta so as to obtain the same pattern as above. When the difference between the rotation speeds of the engine 2 and MG4 falls below a predetermined value at time Tb, the ECT-ECU 13 controls the clutch 3 to an engaged state by suddenly increasing the hydraulic command value in accordance with the rotation speeds of the engine 2 and MG4.

Thus, the ECT-ECU 13 calculates the hydraulic command value according to the rotation speeds of the engine 2 and the MG4, while the EFI-ECU 11 determines the hydraulic command value according to a predetermined pattern. Therefore, the EFI-ECU 11 can engage the clutch 3 without the need for calculation processing similar to that of the ECT-ECU 13.

After the rotation speed of MG4 matches the rotation speed of engine 2, at time T6, EFI-ECU 11 updates the driving status from Ready OFF to Ready ON. This allows the hybrid vehicle to start moving.

Figure 6 is a time chart showing an example of clutch 3 engagement control during MG start. In this example, the vehicle control device 1 starts the engine 2 using the MG 4 to launch the hybrid vehicle. The EFI-ECU 11 engages the clutch 3 using line pressure, and then activates the MG 4 to start the engine 2. For this reason, the hydraulic pressure command value is not used and remains at 0.

At time T10, the EFI-ECU 11 executes engagement control of the clutch 3. The EFI-ECU 11 controls the line pressure switching value to 0 and supplies line pressure to the clutch 3. This completes the engagement of the clutch 3.

After that, at time T11, the EFI-ECU 11 instructs the MG-ECU 12 to start the MG4. The MG4 outputs output torque to the engine 2 during the period from time T11 to T14. This increases the rotation speed of the MG4. At this time, the clutch 3 is in an engaged state, so the rotation speed of the engine 2 increases in conjunction with the increase in the rotation speed of the MG4.

Here, the dotted line portion of the engine 2 rotation speed is the value when no communication failure occurs in the ECT-ECU 13. In this case, the electric oil pump 30 operates, so the engine 2 rotation speed increases in substantially the same way as the MG4 rotation speed. In contrast, when a communication failure occurs in the ECT-ECU 13, the electric oil pump 30 does not operate, and in order for the mechanical oil pump 31 to operate and generate line pressure, the MG4 rotation speed must increase to a predetermined value. For this reason, the engine 2 rotation speed starts to increase from time T13, which is later than time T12 when the MG4 rotation speed starts to increase.

Then, at time T15, the rotation speeds of the engine 2 and the MG4 reach Rn. Then, at time T16 , the EFI-ECU 11 updates the traveling status from Ready-off to Ready-on, thereby enabling the hybrid vehicle to start moving.

Figure 7 is a time chart showing an example of clutch 3 engagement control when starting engine 2 during EV driving. In this example, the vehicle control device 1 starts engine 2 by MG4 during EV driving, thereby transitioning the hybrid vehicle to EHV driving. Here, the output torque of MG4 is torque Tx according to the user's operation. Note that although torque tx is shown as a constant value in Figure 7, it may vary.

At time T21, the EFI-ECU 11 starts controlling the engagement of the clutch 3. The EFI-ECU 11 controls the line pressure switching value to 1 and supplies the line pressure to the linear solenoid valve 34. The EFI-ECU 11 also increases the hydraulic pressure command value to a predetermined value P in one go according to a predetermined pattern for starting the engine 2. This causes the clutch 3 to enter an engaged state.

The dotted line portion of the hydraulic command value is the value when no communication failure occurs in the ECT-ECU 13. In this case, the ECT-ECU 13 gradually increases the hydraulic command value according to the rotation speeds of the engine 2 and MG4. When the hydraulic command value reaches a predetermined value P, the clutch 3 is engaged.

After starting engagement control, at time T22, the EFI-ECU 11 increases the rotation speed of the engine 2. At this time, because the crankshaft 20 and drive shaft 40 have begun to engage, the rotation speed of the MG4 temporarily decreases as the output torque of the MG4 is drawn into the engine 2. After that, at time T23, the engagement of the clutch 3 is completed, and the rotation speed of the MG4 matches the rotation speed (Rn) of the engine 2. This enables the hybrid vehicle to run as an EHV using the driving force of the engine 2 and MG4.

In this way, even if a communication failure occurs with the ECT-ECU 13, the EFI-ECU 11 determines the hydraulic command value related to the engagement state of the clutch 3 according to a predetermined pattern and controls the engagement, so the hybrid vehicle can be driven by the engine 2 without the need for calculation processing by the ECT-ECU 13.

The above-described embodiment is a preferred example of the present invention. However, the present invention is not limited to this embodiment, and various modifications are possible without departing from the spirit of the present invention.

1 Vehicle control device (control device)
2. Engine (internal combustion engine)
3 Clutch 4 Motor generator (rotating electric machine)
11 EFI-ECU (first computer)
12 MG-ECU
13 ECT-ECU (second computer)
54 Drive wheel Sa Hydraulic system

Claims (1)

A control device for a vehicle in which output torque of an internal combustion engine is transmitted to drive wheels via a rotating electric machine,
a first computer that controls engagement of a clutch that engages the shafts of the internal combustion engine and the rotary electric machine based on a control value related to the clutch when the internal combustion engine is cranked by a starter ;
a second computer that calculates the control value in accordance with the rotation speed of the internal combustion engine and the rotating electric machine and transmits the control value to the first computer;
the second computer calculates the control value so that the clutch is brought into an engaged state when a difference between the rotation speeds of the internal combustion engine and the rotating electric machine becomes equal to or smaller than a predetermined value;
when the first computer cannot receive the control value from the second computer, the first computer determines the control value such that the clutch is engaged at a predetermined timing before a difference between the rotation speeds of the internal combustion engine and the rotating electric machine becomes equal to or smaller than the predetermined value.
Control device.

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