Control device and control method for hybrid vehicle

Abstract

A control device and a control method for a hybrid vehicle equipped with an internal combustion engine are provided. The internal combustion engine is equipped with a filter for collecting particulate matter in the exhaust gas in an exhaust passage. The control device executes a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process is a process for responding to a deceleration request of the hybrid vehicle by using a fuel cut-off process. The second deceleration control process is a process for responding to a deceleration request of the hybrid vehicle without using a fuel cut-off process. The selection process is a process for selecting to execute the second deceleration control process when the PM accumulation amount is greater than a threshold value, and selecting to execute the first deceleration control process when the PM accumulation amount is less than the threshold value.

Description

Technical Field

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

[0002] For example, Japanese Patent Publication No. 2017-177823 describes an internal combustion engine having a filter in the exhaust passage for collecting particulate matter (PM) in the exhaust gas. When the temperature of the filter becomes high during the fuel cut-off process, the control device controlling the internal combustion engine reduces the throttle opening. This is to reduce the amount of oxygen supplied to the filter and suppress the temperature rise of the filter.

[0003] When the fuel cut process is used to generate the deceleration of the vehicle, the throttle opening degree during the fuel cut process is set to a small value. Therefore, there is a limit to further reducing the throttle opening degree. Summary of the invention

[0004] Hereinafter, a plurality of aspects and effects related to the present disclosure will be described.

[0005] Embodiment 1. According to one embodiment of the present disclosure, there is provided a control device for a hybrid vehicle, the hybrid vehicle comprising an internal combustion engine and a rotating electric machine, wherein the internal combustion engine comprises a filter configured to collect particulate matter in exhaust gas in an exhaust passage, the control device comprising a processing circuit, the processing circuit being configured to execute a first deceleration control process, a second deceleration control process, and a selection process, the first deceleration control process being a process for responding to a deceleration request of the hybrid vehicle by using a fuel cut-off process, the fuel cut-off process being a process for stopping combustion control of fuel in a cylinder of the internal combustion engine, the second deceleration control process being a process for responding to a deceleration request of the hybrid vehicle without using the fuel cut-off process, the selection process being a process for selecting to execute the second deceleration control process when a PM accumulation amount is greater than a threshold value, and selecting to execute the first deceleration control process when the PM accumulation amount is less than the threshold value, the PM accumulation amount being an amount of particulate matter accumulated on the filter.

[0006] When the PM accumulation amount is large, there is a tendency that the amount of particulate matter oxidized increases due to the inflow of oxygen into the filter. Therefore, when the fuel cut process is performed when the PM accumulation amount is large, the temperature of the filter may become excessively high. Therefore, in the above structure, when the PM accumulation amount is greater than the threshold, the deceleration request for the hybrid vehicle is responded to regardless of the fuel cut process. As a result, it is possible to suppress the excessive increase in the temperature of the filter.

[0007] Method 2. In the control device of the hybrid vehicle described in the above-mentioned method 1, the selection processing may also include a processing for variably setting the threshold value according to the temperature of the filter, and the threshold value set when the temperature of the filter is high is lower than the threshold value set when the temperature of the filter is low.

[0008] When the filter temperature is high, the filter temperature is likely to exceed the permissible range when the fuel cut process is executed. Therefore, in the above configuration, by setting the threshold value according to the filter temperature, an appropriate compromise can be achieved between executing the first deceleration control process as much as possible and suppressing the filter temperature from excessively increasing.

[0009] Method 3. In the control device of the hybrid vehicle described in the above-mentioned method 1 or 2, it may also be that the hybrid vehicle has a speed ratio adjustment device and a power storage device, the crankshaft of the internal combustion engine is configured to be mechanically connected to the drive wheel via the speed ratio adjustment device, the speed ratio adjustment device is configured to adjust the ratio of the rotational speed of the crankshaft to the rotational speed of the drive wheel, the power storage device is configured to be charged by the regenerative power of the rotating electric machine, and the second deceleration control processing includes setting the regenerative power and the internal combustion engine speed according to the charging rate of the power storage device, the regenerative power set when the charging rate of the power storage device is large is less than the regenerative power set when the charging rate is small, and the internal combustion engine speed set when the charging rate of the power storage device is large is greater than the internal combustion engine speed set when the charging rate is small.

[0010] On the basis of making the deceleration force the same, when the regenerative power is small, the speed of the internal combustion engine needs to be increased compared to when the regenerative power is large. Therefore, in the above structure, the speed of the internal combustion engine when the regenerative power is small is set to be greater than the speed of the internal combustion engine when the regenerative power is large. In this way, the deceleration force can be suppressed from changing due to the size of the regenerative power. In addition, when the PM accumulation amount is greater than the threshold, the second deceleration control process is performed regardless of the size of the charging rate, thereby also suppressing the deceleration force from changing due to the change of the charging rate.

[0011] Mode 4. In the control device for a hybrid vehicle according to any one of Modes 1 to 3, the processing circuit may be configured to execute a notification process for notifying a user that the deceleration is limited to a smaller side before executing the second deceleration control process.

[0012] In the above configuration, by executing the notification process, the user can be made aware in advance that the deceleration is limited to a smaller side.

[0013] Method 5. In the control device of a hybrid vehicle described in any one of the above methods 1 to 4, the processing circuit may be configured to perform a gradual change process, wherein the gradual change process is as follows: when the PM accumulation amount becomes greater than the threshold value during the execution of the first deceleration control process, the deceleration is gradually transferred to a deceleration that can be achieved by the second deceleration control process in the first deceleration control process before switching to the second deceleration control process.

[0014] In the above configuration, the deceleration is gradually changed when switching from the first deceleration control process to the second deceleration control process. This can prevent the user from feeling uncomfortable with the behavior of the hybrid vehicle.

[0015] Method 6. In the control device of a hybrid vehicle described in any one of the above methods 1 to 5, the processing circuit may be configured to execute the second deceleration control processing according to the deceleration requirement of the hybrid vehicle even if the PM accumulation amount is less than the threshold value when there is a historical record of executing the second deceleration control processing within one trip.

[0016] In the above configuration, when the second deceleration control process is executed once, the second deceleration control process is adopted during the trip even if the PM accumulation amount is less than the threshold value. Therefore, it is possible to suppress frequent switching of the deceleration of the hybrid vehicle.

[0017] Method 7. According to one method of the present disclosure, a control method for a hybrid vehicle is provided, the hybrid vehicle comprising an internal combustion engine and a rotating electric machine, the internal combustion engine comprising a filter in an exhaust passage configured to capture particulate matter in the exhaust gas, the control method comprising executing a first deceleration control process, a second deceleration control process and a selection process, the first deceleration control process being a process of responding to a deceleration request of the hybrid vehicle by utilizing a fuel cut-off process, the fuel cut-off process being a process of stopping combustion control of fuel in a cylinder of the internal combustion engine, the second deceleration control process being a process of responding to a deceleration request of the hybrid vehicle without utilizing the fuel cut-off process, the selection process being a process of selecting to execute the second deceleration control process when a PM accumulation amount is above a threshold value and selecting to execute the first deceleration control process when the PM accumulation amount is less than the threshold value, the PM accumulation amount being the amount of particulate matter accumulated on the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram showing the structure of a vehicle according to the first embodiment.

[0019] Figure 2 This is a flowchart showing the procedure of a process executed by the control device according to the first embodiment.

[0020] Figure 3 It is a diagram showing the tendency of the mapping data involved in the first embodiment.

[0021] Figure 4 This is a flowchart showing the procedure of a process executed by the control device according to the first embodiment.

[0022] Figure 5 This is a flowchart showing the procedure of a process executed by the control device according to the first embodiment.

[0023] Figure 6 This is a flowchart showing the procedure of a process executed by the control device according to the second embodiment.

[0024] Figure 7 It is a timing chart showing the operation of the second embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, a first embodiment will be described with reference to the drawings.

[0026] "Premise Structure"

[0027] like Figure 1 As shown, the internal combustion engine 10 has four cylinders #1 to #4. A throttle valve 14 is provided in the intake passage 12 of the internal combustion engine 10. An intake port injection valve 16 for injecting fuel into the intake port 12a is provided in the downstream portion of the intake passage 12. The air sucked into the intake passage 12 and the fuel injected from the intake port injection valve 16 flow into the combustion chamber 20 as the intake valve 18 is opened. Fuel is injected into the combustion chamber 20 from the in-cylinder injection valve 22. In addition, the mixture of air and fuel in the combustion chamber 20 is combusted with the spark discharge of the ignition device 24. The combustion energy generated at this time is converted into the rotational energy of the crankshaft 26.

[0028] The mixture burned in the combustion chamber 20 is discharged as exhaust gas to the exhaust passage 30 as the exhaust valve 28 is opened. A three-way catalyst 32 having oxygen storage capacity and a gasoline particulate filter (GPF 34) are provided in the exhaust passage 30. The GPF 34 is a filter for collecting PM and a three-way catalyst is supported.

[0029] The crankshaft 26 is mechanically connected to the planetary carrier C of the planetary gear mechanism 50 constituting the power distribution device. The rotating shaft 52a of the first motor generator 52 is mechanically connected to the sun gear S of the planetary gear mechanism 50. In addition, the rotating shaft 54a of the second motor generator 54 and the drive wheel 60 are mechanically connected to the ring gear R of the planetary gear mechanism 50. An AC voltage is applied to the terminals of the first motor generator 52 through the first converter 56. In addition, an AC voltage is applied to the terminals of the second motor generator 54 through the second converter 58. Both the first converter 56 and the second converter 58 are power conversion circuits that convert the terminal voltage of the battery 59, which is a DC voltage source, into an AC voltage and output it.

[0030] The control device 70 controls the internal combustion engine 10. The control device 70 operates the operating parts of the internal combustion engine 10 such as the throttle valve 14, the intake port injection valve 16, the in-cylinder injection valve 22, and the ignition device 24 in order to control the torque and the exhaust component ratio of the control amount as the control object. In addition, the control device 70 operates the first inverter 56 in order to control the torque of the first motor generator 52 as the control object. In addition, the control device 70 operates the second inverter 58 in order to control the torque of the second motor generator 54 as the control object. Figure 1 1 and 2. The control device 70 includes the operation signals MS1 to MS6 of the throttle valve 14, the port injection valve 16, the in-cylinder injection valve 22, the ignition device 24, the first converter 56, and the second converter 58. In order to control the control amount of the internal combustion engine 10, the control device 70 refers to the intake air amount Ga detected by the air flow meter 80 and the output signal Scr of the crank angle sensor 82. In addition, the control device 70 refers to the water temperature THW detected by the water temperature sensor 84 and the output signal Sp of the output side rotation angle sensor 86 that detects the rotation angle of the ring gear R. In addition, the control device 70 refers to the charge and discharge current I of the battery 59 detected by the current sensor 88. In addition, the control device 70 refers to the temperature Tb of the battery 59 detected by the temperature sensor 89. In addition, in order to control the control amount of the first motor generator 52, the control device 70 refers to the output signal Sm1 of the first rotation angle sensor 90 that detects the rotation angle of the first motor generator 52. In addition, in order to control the control amount of the second motor generator 54, the control device 70 refers to the output signal Sm2 of the second rotation angle sensor 92 that detects the rotation angle of the second motor generator 54. In addition, the control device 70 refers to the acceleration operation amount ACCP, which is the amount of depression of the accelerator pedal detected by the acceleration sensor 94, and the shift variable Vsft detected by the gear position sensor 96. The shift variable Vsft is a variable indicating the gear position such as the D gear, the B gear, the P gear, and the N gear.

[0031] The control device 70 includes a CPU 72, a ROM 74, and a peripheral circuit 76, which can communicate via a communication line 78. Here, the peripheral circuit 76 includes a circuit for generating a clock signal that specifies internal operations, a power supply circuit, a reset circuit, etc. The control device 70 controls the control amount by the CPU 72 executing a program stored in the ROM 74.

[0032] "Processing related to the protection of GPF34"

[0033] Figure 2 2 shows the steps of the process related to the protection of the GPF 34 . Figure 2 The processing shown is realized by the CPU 72 repeatedly executing, for example, a program stored in the ROM 74 in a predetermined cycle. In the following, the step number of each process is represented by a number with "S" at the beginning.

[0034] exist Figure 2 In the series of processing shown, the CPU 72 first obtains the engine speed NE, the charging efficiency η and the water temperature THW (S10). The engine speed NE is calculated by the CPU 72 based on the output signal Scr. The charging efficiency η is calculated by the CPU 72 based on the intake air amount Ga and the engine speed NE. Next, the CPU 72 calculates the temperature Tgpf of the GPF 34 and the update amount ΔDPM of the PM accumulation amount DPM based on the engine speed NE, the charging efficiency η and the water temperature THW (S12). Here, the PM accumulation amount DPM is the amount of PM trapped by the GPF 34. In detail, the CPU 72 calculates the amount of PM in the exhaust gas discharged to the exhaust passage 30 based on the engine speed NE, the charging efficiency η and the water temperature THW. In addition, the CPU 72 calculates the temperature Tgpf of the GPF 34 based on the engine speed NE and the charging efficiency η. In addition, the CPU 72 calculates the update amount ΔDPM based on the amount of PM in the exhaust gas and the temperature Tgpf of the GPF 34. Next, the CPU 72 substitutes a value obtained by adding the update amount ΔDPM to the PM accumulation amount DPM into the PM accumulation amount DPM ( S14 ).

[0035] Next, the CPU 72 takes the PM accumulation amount DPM and the temperature Tgpf as inputs, and calculates the FC time Tfc that can be continued to perform the fuel cut process (S16). The FC time Tfc is the upper limit time that the temperature Tgpf of the GPF 34 does not become excessively high. This process is realized by the CPU 72 performing a mapping operation on the FC time Tfc in a state where mapping data that takes the PM accumulation amount DPM and the temperature Tgpf as input variables and takes the FC time Tfc as an output variable is stored in the ROM 74 in advance.

[0036] exist Figure 3 The mapping data is illustrated in FIG.

[0037] like Figure 3 As shown, the FC time Tfc when the PM accumulation amount DPM is large is less than the FC time Tfc when the PM accumulation amount DPM is small. This is because the greater the PM accumulation amount DPM, the greater the amount of PM oxidation per unit time when oxygen flows into the GPF 34. In addition, the FC time Tfc when the temperature Tgpf is high is less than the FC time Tfc when the temperature Tgpf is low. This is because the higher the temperature Tgpf, the shorter the time until the temperature Tgpf reaches the upper limit value.

[0038] In addition, the mapping data is a set of discrete values ​​of input variables and values ​​of output variables corresponding to the values ​​of the input variables. In addition, when the value of the input variable is consistent with one of the values ​​of the input variable of the mapping data, the mapping operation is set to process the value of the output variable of the corresponding mapping data as the result of the operation. In addition, when the value of the input variable is inconsistent with the value of the input variable of the mapping data, the mapping operation is set to process the value obtained by interpolating the values ​​of multiple output variables contained in the mapping data as the result of the operation. In addition, when the value of the input variable is inconsistent with the value of the input variable of the mapping data, the mapping operation can also be set to process the value of the output variable of the mapping data corresponding to the closest value among the values ​​of the multiple output variables contained in the mapping data as the result of the operation.

[0039] return Figure 2 The CPU 72 determines whether the protection flag F1 is "1" (S18). The protection flag F1 is "1" when the process of overheat protection of the GPF 34 is executed. The protection flag F1 is "0" when the process of overheat protection of the GPF 34 is not executed.

[0040] When the CPU 72 determines that the protection flag F1 is "0" (S18: No), it determines whether the FC time Tfc is less than the threshold value Tth (S20). This process is a process for determining whether to change the size of the required drive torque Tp* when the acceleration operation amount ACCP is less than a predetermined value. The threshold value Tth is set according to the average duration of the required drive torque Tp* being negative. The threshold value Tth can be set to "5s" or less, for example.

[0041] The processing of S20 is equivalent to the processing of determining whether the PM accumulation amount DPM is greater than a threshold value. The threshold value is set according to the temperature Tgpf. Figure 3 2 shows the threshold values ​​Dα and Dβ of the PM accumulation amount DPM when the temperature Tgpf is respectively Tα and Tβ. Figure 3 As shown, the threshold value Dα when the temperature Tgpf is the temperature Tα is smaller than the threshold value Dβ when the temperature Tgpf is the temperature Tβ lower than the temperature Tα.

[0042] return Figure 2 When the CPU 72 determines that the value is below the threshold value Tth (S20: Yes), Figure 1 The human-machine interface 98 shown is operated to inform the user of the change in deceleration (S22). This process, for example, can be set to light up the warning light when the human-machine interface 98 is a warning light. However, the meaning of lighting up is recorded in advance in the manual of the vehicle VC. However, the human-machine interface 98 is not limited to a device that outputs visual information. For example, it can also be a speaker. In this case, for example, it can output voice information such as "transfer to a mode that prioritizes the protection of GPF34".

[0043] Then, the CPU 72 waits until a predetermined time T1 having a predetermined length has passed since the execution of the process of S22 (S24: No). If it is determined that the predetermined time T1 has passed (S24: Yes), the CPU 72 substitutes "1" for the protection flag F1 (S26).

[0044] On the other hand, when the CPU 72 determines that the protection flag F1 is "1" (S18: Yes), it determines whether the trip is completed (S28). Here, the trip refers to the period during which the driving permission switch of the vehicle is in the on state. The driving permission switch may be, for example, a switch that opens and closes the electrical path between the battery 59 and the first converter 56 and the second converter 58, which is in the closed state.

[0045] When the CPU 72 determines that the trip is completed ( S28 : YES), it substitutes “0” into the protection flag F1 ( S29 ).

[0046] When the CPU 72 completes the processing of S26 and S29 or makes a negative determination in the processing of S20 and S28, it temporarily terminates the processing. Figure 2 A series of processing is shown.

[0047] "Processing related to control of motor generator"

[0048] Figure 4 2 shows the steps of processing related to the control of the outputs of the first motor generator 52 and the second motor generator 54. Figure 4 The processing shown is realized by the CPU 72 repeatedly executing a program stored in the ROM 74 at a predetermined cycle, for example.

[0049] exist Figure 4In the series of processing shown, the CPU 72 obtains the acceleration operation amount ACCP, the output side speed Np and the shift variable Vsft (S30). Here, the output side speed Np is the speed of the ring gear R of the planetary gear mechanism 50. The output side speed Np is a variable indicating the speed of the drive wheel 60. In other words, it is a variable indicating the vehicle speed. The output side speed Np is calculated by the CPU 72 based on the output signal Sp.

[0050] Next, the CPU 72 determines whether the protection flag F1 is "0" (S32). When the CPU 72 determines that the protection flag F1 is "0" (S32: Yes), the CPU 72 uses the normal mapping to calculate the required drive torque Tp* (S36) as the torque required for the drive wheel 60. The mapping data of the normal mapping is data that sets the required drive torque Tp* when the acceleration operation amount ACCP is less than a predetermined value to a value that can be achieved when the fuel cut-off process is performed. Here, the value that can be achieved when the fuel cut-off process is performed refers to a value that can be achieved when the fuel cut-off process is performed regardless of the size of the charging rate SOC. In other words, it refers to a value that can be achieved even if the second electric generator 54 is not regeneratively controlled. In addition, the minimum value of the required drive torque Tp* in the B gear can be set according to the output of the internal combustion engine 10 that can be achieved when the fuel cut-off process is performed and the internal combustion engine speed NE is set to the maximum speed.

[0051] On the other hand, when the CPU 72 determines that the protection flag F1 is "1" (S32: No), the CPU 72 uses the protection map to calculate the torque required by the drive wheel 60, that is, the required drive torque Tp* (S34). The protection map data is data that sets the required drive torque Tp* when the acceleration operation amount ACCP is less than a predetermined value to a value that can be achieved by the load torque of the internal combustion engine 10 without performing the fuel cut-off process. Here, the value that can be achieved by the load torque of the internal combustion engine 10 without performing the fuel cut-off process refers to a value that can be achieved regardless of the size of the charge rate SOC. The required drive torque Tp* in this case is set to a value that can be achieved by the minimum charging efficiency η, which can set the internal combustion engine speed NE to a high speed as much as possible and stabilize the combustion of the internal combustion engine 10. Specifically, in the case of the D range, the required drive torque Tp* is set to a value that can be achieved by the minimum charging efficiency η, which can set the internal combustion engine speed NE to a value smaller than the maximum value by a certain amount and stabilize the combustion of the internal combustion engine 10. On the other hand, in the case of the B range, the required drive torque Tp* is set to a value that can be achieved by the minimum charging efficiency η, which can set the internal combustion engine speed NE to the maximum value and stabilize the combustion of the internal combustion engine 10. In addition, the CPU 72 preferably controls the air-fuel ratio of the mixture in the combustion chamber 20 to the theoretical air-fuel ratio. Thereby, the amount of oxygen flowing into the GPF 34 can be made substantially zero.

[0052] When CPU72 completes the processing of S34 and S36, it substitutes the product of the required driving torque Tp* and the output side rotation speed Np into the driving output Pp* (S38). Next, CPU72 calculates the required charge and discharge power Pbatt* of the battery 59 based on the charge rate SOC of the battery 59 and the temperature Tb of the battery 59 (S40). The required charge and discharge power Pbatt* is positive when discharging. In detail, when the charge rate SOC is below a predetermined value, CPU72 sets the required charge and discharge power Pbatt* to negative in order to charge the battery 59. In addition, the charge rate SOC is calculated by CPU72 based on the charge and discharge current I.

[0053] Next, the CPU 72 substitutes the value obtained by subtracting the product of the required charge / discharge power Pbatt* and the conversion efficiency Kef from the running output Pp* into the system output Ps* (S42).

[0054] Next, the CPU 72 calculates the target internal combustion engine speed NE* and the target first speed Nmg1* (S44). Here, the target internal combustion engine speed NE* is a target value of the internal combustion engine speed NE. In addition, the target first speed Nmg1* is a target value of the first speed Nmg1, which is the speed of the rotating shaft 52a of the first motor generator 52. In detail, the processing of S44 becomes the following processing.

[0055] CPU72 first sets the required internal combustion engine output Pe* according to the system output Ps*. Here, CPU72 may also substitute the system output Ps* into the required internal combustion engine output Pe*. However, instead, CPU72 may substitute the system output Ps* plus the value obtained by the operation amount used to control the charge and discharge power Pbatt to the required charge and discharge power Pbatt* into the required internal combustion engine output Pe*. Then, CPU72 calculates the target internal combustion engine speed NE* based on the required internal combustion engine output Pe*. This can be achieved by CPU72 performing a mapping operation on the target internal combustion engine speed NE* in a state where the mapping data is pre-stored in ROM74. Here, the mapping data is data that takes the required internal combustion engine output Pe* as an input variable and the target internal combustion engine speed NE* as an output variable.

[0056] Next, the CPU 72 calculates the target first rotation speed Nmg1* based on the following equation.

[0057] NE*={ρ / (1+ρ)}·Nmg1*+{1 / (1+ρ)}·Np

[0058] The planetary gear ratio ρ in the above formula is a value obtained by dividing the number of teeth of the sun gear S by the number of teeth of the ring gear R.

[0059] Next, the CPU 72 substitutes a value obtained by subtracting the first rotation speed Nmg1 from the target first rotation speed Nmg1* into the error err1 ( S46 ). The first rotation speed Nmg1 is calculated by the CPU 72 based on the output signal Sm1 .

[0060] Next, the CPU 72 substitutes the value obtained by dividing the required internal combustion engine output Pe* by the target internal combustion engine speed NE* into the internal combustion engine torque base value Teb (S48).

[0061] Next, CPU72 calculates the required first torque Tmg1* (S50). The required first torque Tmg1* is the required torque for the first electric generator 52. CPU72 sets the required first torque Tmg1* to the sum of the open-loop term and the feedback term. Here, the open-loop term is "{-ρ / (1+ρ)}·Teb". Here, "-ρ / (1+ρ)" is the coefficient for converting the torque of the planetary carrier C into the torque of the sun gear S. On the other hand, the feedback term is the operation amount used for feedback control of the first speed Nmg1. The feedback term is the sum of the output value of the proportional element and the output value of the integral element. The output value of the proportional element is the value obtained by multiplying the error err1 by the proportional gain Kp. The output value of the integral element is the cumulative value of the value obtained by multiplying the error err1 by the integral gain Ki.

[0062] Next, the CPU 72 substitutes the value obtained by multiplying the required first torque Tmg1* by "(-1) / ρ" into the straight-line torque Ted (S52). Here, "(-1) / ρ" is a coefficient for converting the torque of the sun gear S into the torque of the ring gear R. The straight-line torque Ted is a torque assumed to be applied to the ring gear R in calculation.

[0063] Next, the CPU 72 calculates the required second torque Tmg2* by subtracting the linear torque Ted from the required drive torque Tp* (S54). Here, the value obtained by subtracting the linear torque Ted from the required drive torque Tp* is the output shortfall of the ring gear R when the torque of the drive wheel 60 is set to the required drive torque Tp*.

[0064] Next, the CPU 72 outputs the operation signal MS5 to the first inverter 56 and outputs the operation signal MS6 to the second inverter 58 (S56). That is, the CPU 72 operates the first inverter 56 to control the torque of the first motor generator 52 to the required first torque Tmg1*. In addition, the CPU 72 operates the second inverter 58 to control the torque of the second motor generator 54 to the required second torque Tmg2*.

[0065] When the CPU 72 completes the processing of S56, it temporarily terminates the Figure 4 A series of processing is shown.

[0066] "Operation of the throttle valve 14"

[0067] Figure 5 2 shows the steps of the process related to the operation of the throttle valve 14 . Figure 5 The processing shown is realized by the CPU 72 repeatedly executing a program stored in the ROM 74 at a predetermined cycle, for example.

[0068] exist Figure 5 In the series of processing shown, CPU72 first obtains the required internal combustion engine output Pe* and the target internal combustion engine speed NE* (S60). Then, CPU72 substitutes the value obtained by dividing the required internal combustion engine output Pe* by the target internal combustion engine speed NE* into the required internal combustion engine torque Te* (S62). Next, CPU72 calculates the command value of the opening degree of the throttle valve 14 based on the required internal combustion engine torque Te*, that is, the throttle opening degree command value TA* (S64). The throttle opening degree command value TA* calculated here is used to set the torque of the internal combustion engine 10 to the value of the required internal combustion engine torque Te*. Then, CPU72 outputs an operation signal MS1 to the throttle valve 14 in order to control the opening degree of the throttle valve 14 to the throttle opening degree command value TA* (S66).

[0069] When the CPU 72 completes the processing of S66, it temporarily ends the Figure 5 A series of processing is shown.

[0070] "Functions and Effects of the Present Embodiment"

[0071] The CPU 72 calculates the required drive torque Tp* based on the acceleration operation amount ACCP and the output side speed Np, and based on this, operates various operation parts of the internal combustion engine 10 and the first converter 56 and the second converter 58. When the acceleration operation amount ACCP is less than a predetermined amount, the CPU 72 sets the required drive torque Tp* to a negative value. Here, usually, the CPU 72 sets the required drive torque Tp* to a value that can be achieved by the internal combustion engine 10 executing the fuel cut process.

[0072] In addition, the CPU 72 calculates the amount of particulate matter deposited on the GPF 34, that is, the PM deposit amount DPM, and the temperature Tgpf of the GPF 34. Then, based on these, the CPU 72 calculates the upper limit time for which the temperature of the GPF 34 does not exceed the allowable range as the FC possible time Tfc, assuming that the fuel cut process is continued. Then, when the FC possible time Tfc becomes less than the threshold value Tth, the CPU 72 changes the map data for calculating the required drive torque Tp* to the map data for protection of the GPF 34. The map data for protection is set to a value that can be achieved based on the load torque of the internal combustion engine 10 when the fuel cut process is not performed. Therefore, even when the required drive torque Tp* cannot be achieved by the power generation of the second motor generator 54, the CPU 72 can achieve the required drive torque Tp* by the load torque of the internal combustion engine 10 without performing the fuel cut process. That is, the CPU 72 reduces the charging efficiency η of the internal combustion engine 10 according to the accelerator operation amount ACCP, and controls the internal combustion engine speed NE by the operation of the first inverter 56, thereby generating a negative drive force. Therefore, the oxygen concentration in the fluid flowing into the GPF 34 can be reduced, and the temperature of the GPF 34 can be suppressed from excessively rising due to oxidation of PM in the GPF 34 .

[0073] According to the present embodiment described above, the following operations and effects can also be obtained.

[0074] (1) The CPU 72 notifies the driver of the selection of the protection map data before selecting the protection map data. This can prevent the driver from having the impression that the deceleration in response to the acceleration operation has suddenly changed. Therefore, it can prevent the driver from feeling uncomfortable.

[0075] (2) Regardless of the current charge rate SOC, the CPU 72 switches to the protection map data when the FC possible time Tfc is equal to or less than the threshold value Tth. This allows the deceleration relative to the acceleration operation to be constant regardless of the charge rate SOC.

[0076] (3) When the CPU 72 uses the protective map to decelerate the vehicle VC, the internal combustion engine speed NE is set according to the charge rate SOC of the battery 59. That is, according to the processing of S42, the system output Ps* is determined according to the charge rate SOC. That is, the required internal combustion engine output Pe* is determined according to the charge rate SOC. Then, in the processing of S44, the CPU 72 determines the target internal combustion engine speed NE* according to the required internal combustion engine output Pe*. Therefore, when the system output Ps* is a value that decelerates the vehicle VC, the target internal combustion engine speed NE* when the charge rate SOC is large becomes greater than the target internal combustion engine speed NE* when the charge rate SOC is small. As a result, when the regenerative power of the second motor generator 54 is small, the internal combustion engine speed NE can be increased compared to the case where the regenerative power is large. As a result, the deceleration force can be suppressed from changing due to the size of the regenerative power.

[0077] (4) Regardless of whether the fuel cut process is currently being performed, the CPU 72 switches to the protection map data when the FC possible time Tfc is equal to or less than the threshold value Tth, and notifies the user of this fact. Therefore, the switching of the deceleration speed with respect to the acceleration operation can be reliably notified in advance.

[0078] (5) In the map data for protection, the deceleration in the B range is also made greater than the deceleration in the D range. Thus, even after the map data for protection is switched, the difference in deceleration due to the gear position can be felt.

[0079] <Second embodiment>

[0080] Hereinafter, the second embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

[0081] In the present embodiment, when the deceleration protection flag F1 is switched from "0" to "1", a process of gradually increasing the driving force is executed.

[0082] Figure 6 The steps related to the above-mentioned processing are shown in FIG. Figure 6 The processing shown is realized by the CPU 72 repeatedly executing a program stored in the ROM 74 at a predetermined cycle, for example.

[0083] exist Figure 6 In the series of processes shown, the CPU 72 determines whether the gradual change flag F2 is "1" (S70). When the gradual change flag F2 is "1", it indicates that the process of gradually increasing the driving force to a value that can be achieved by the protection map is being executed. When the gradual change flag F2 is "0", it indicates that the above-mentioned gradual increase process is not being executed.

[0084] When the CPU 72 determines that the gradual change flag F2 is "0" (S70: No), it determines whether the protection flag F1 is switched from "0" to "1" (S72). When the CPU 72 determines that it is switched (S72: Yes), it determines whether the vehicle VC is in a deceleration period (S74). When the CPU 72 determines that it is in a deceleration period (S74: Yes), it substitutes "1" for the gradual change flag F2 (S76).

[0085] When the CPU 72 determines that the gradual change flag F2 is "1" (S70: Yes) and the processing of S76 is completed, the CPU 72 gradually increases the required drive torque Tp* (S78). Then, the CPU 72 determines whether the gradual increase processing is completed (S80). The CPU 72 determines that the gradual increase processing is completed when the required drive torque Tp* becomes a value that can be achieved using the protection map.

[0086] When the CPU 72 determines that the gradual increase process is completed (S80: YES), it substitutes "0" into the gradual change flag F2 (S84).

[0087] When the CPU 72 completes the processing of S84 or makes a negative determination in the processing of S72, S74, and S80, it temporarily terminates the processing. Figure 6 A series of processing is shown.

[0088] "Functions and Effects of the Second Embodiment"

[0089] Figure 7 The following is an example of processing when the protection flag F1 is switched from "0" to "1" during deceleration. Figure 7 In FIG. 5 , the PM accumulation amount DPM at which the FC time Tfc can become equal to or smaller than the threshold value Tth, that is, the threshold value of the PM accumulation amount DPM is indicated by a dashed line.

[0090] like Figure 7 As shown in FIG. 1 , if the FC time Tfc becomes less than the threshold value Tth at time t1, the CPU 72 switches the protection flag F1 from "0" to "1" at time t2 after a predetermined time T1 has passed from the time. Then, as shown in FIG. Figure 7 As indicated by the solid line in the middle, the CPU 72 gradually increases the required drive torque Tp*. Then, at time t3 when the required drive torque Tp* reaches a value achievable by the protection map, the CPU 72 switches the map used for calculating the required drive torque Tp* from the normal map to the protection map.

[0091] <Correspondence>

[0092] Hereinafter, the correspondence relationship is shown according to the numbers of the embodiments described in the column of “Summary of the Invention”.

[0093] [1, 7] The rotating electric machine corresponds to the second electric generator 54. The filter corresponds to the GPF 34. The first deceleration control process corresponds to the processes of S36, S38 to S56, and S60 to S66 when the required drive torque Tp* is negative. The second deceleration control process corresponds to the processes of S34, S38 to S56, and S60 to S66 when the required drive torque Tp* is negative. The fuel cut process corresponds to the process that can be performed by the process of S36. The selection process corresponds to Figure 2 The threshold value corresponds to the threshold values ​​Dα and Dβ.

[0094] [2] corresponds to the threshold Dα being smaller than the threshold Dβ.

[0095] [3] The speed ratio adjustment device corresponds to the planetary gear mechanism 50 and the first motor generator 52. The power storage device corresponds to the battery 59.

[0096] [4] The notification process corresponds to the process of S22.

[0097] [5] The gradient processing corresponds to the processing of S78.

[0098] [6] Figure 2 In the case where the process of S26 is executed, the process of S29 is not performed unless the trip is completed.

[0099] <Other embodiments>

[0100] In addition, the present embodiment can be implemented by being modified as follows. The present embodiment and the following modified examples can be implemented in combination with each other within the range that there is no technical contradiction.

[0101] “Regarding the First Deceleration Control Process”

[0102] The first deceleration control process is not limited to the process of executing the processes of S36, S38 to S56, and S60 to S66. For example, it may be a process of generating a braking force only by a fuel cut process. In other words, it may be a process of responding to a deceleration request only by the load torque of the internal combustion engine 10 without responding to a deceleration request by the cooperation of the regenerative control of the rotating electric machine and the load torque of the fuel cut process.

[0103] “Regarding the Second Deceleration Control Process”

[0104] The second deceleration control process is not limited to the process of responding to the deceleration request by controlling the rotation speed of the first motor generator 52. For example, as described in the column "Regarding the gear ratio adjustment device" below, when the vehicle is equipped with a step-variable transmission, the deceleration request may be responded to by adjusting the gear ratio of the step-variable transmission. In this case, when the regenerative power of the second motor generator 54 is small, the gear ratio is operated so as to further increase the internal combustion engine speed NE.

[0105] The second deceleration control process is not limited to a process for generating a desired braking force by cooperating with the regenerative power of the rotating electric machine. For example, it may be a process for generating a desired braking force only by the power of the internal combustion engine 10. In other words, it may be a process for responding to a deceleration request only by the load torque of the internal combustion engine 10, without responding to a deceleration request by cooperating with the regenerative control of the rotating electric machine and the load torque of the internal combustion engine 10.

[0106] It is not essential to set the required driving torque Tp* to different values ​​in the B range and the D range.

[0107] "About Selection Processing"

[0108] The process is not limited to selecting which of the two processes, the first deceleration control process and the second deceleration control process, to adopt based on whether the FC time Tfc is below the threshold value Tth. For example, the CPU 72 may determine whether the PM accumulation amount DPM is above the threshold value. Here, the CPU 72 may also variably set the threshold value based on the temperature Tgpf. However, it is not necessary to variably set the threshold value.

[0109] “Regarding the execution period of the first deceleration control process and the second deceleration control process”

[0110] In the above embodiment, when the protection flag F1 is set to "1", the protection flag F1 is not set to "0" during the trip, but the present invention is not limited to this. In other words, when the second deceleration control process is temporarily selected, the first deceleration control process is not selected during the trip, but the present invention is not limited to this. For example, when the duration of the state in which the FC-enabled time Tfc is greater than the threshold value Tth is longer than a predetermined time, "0" may be substituted for the protection flag F1.

[0111] In the above embodiment, the protection flag F1 is switched from "0" to "1" in the middle of the trip, but the present invention is not limited to this. For example, the protection flag F1 may be switched only at the beginning and end of the trip. Figure 2 In other words, the process of selecting which of the first deceleration control process and the second deceleration control process to adopt may be executed only at the beginning of the trip.

[0112] "About the speed ratio adjustment device"

[0113] The speed ratio adjustment device is not limited to the one including the planetary gear mechanism 50 and the first motor generator 52. For example, a transmission device such as a step-variable transmission device that changes the speed ratio by changing the engagement state of a plurality of gears may be used.

[0114] "About Hybrid Vehicles"

[0115] The hybrid vehicle is not limited to a series-parallel hybrid vehicle, and may be a parallel hybrid vehicle, for example.

[0116] The control device 70 is not limited to a device that includes a CPU 72 and a ROM 74 and executes software processing. For example, a dedicated hardware circuit such as an ASIC that processes at least a part of the software processing executed in the above-mentioned embodiment may be provided. That is, the control device 70 only needs to be any one of the following structures (a) to (c). (a) A processing device that executes all of the above-mentioned processing according to a program and a program storage device such as a ROM that stores the program. (b) A processing device that executes a part of the above-mentioned processing according to a program and a program storage device and a dedicated hardware circuit that executes the remaining processing. (c) A dedicated hardware circuit that executes all of the above-mentioned processing. Here, the software execution device and the dedicated hardware circuit that include the processing device and the program storage device may be multiple. That is, the above-mentioned processing may be executed by a processing circuit (processing circuitry) that includes at least one of one or more software execution devices and one or more dedicated hardware circuits. The program storage device, i.e., the computer-readable medium, includes all available media that can be accessed by a general-purpose or dedicated computer.

[0117] <Note>

[0118] A vehicle deceleration control device is applied to a vehicle equipped with an internal combustion engine and a gear ratio adjustment device, wherein the internal combustion engine is equipped with a filter for collecting particulate matter in the exhaust gas in an exhaust passage, the crankshaft of the internal combustion engine can be mechanically connected to a drive wheel via the gear ratio adjustment device, the gear ratio adjustment device is a device for adjusting the ratio of the rotation speed of the crankshaft to the rotation speed of the drive wheel, the vehicle deceleration control device performs deceleration control processing, prediction processing and restriction processing, the deceleration control processing is to operate the gear ratio adjustment device to control the deceleration of the vehicle when a deceleration request of the vehicle is generated The deceleration control process includes a fuel cut-off process, at least in the case where the limiting process is not executed, the fuel cut-off process is a process of stopping the supply of fuel to the cylinders of the internal combustion engine, the prediction process is a process of predicting whether the temperature of the filter will rise beyond an allowable range due to the execution of the fuel cut-off process corresponding to the deceleration request based on the amount of particulate matter captured by the filter, and the limiting process is a process of limiting the deceleration of the vehicle when the deceleration request of the vehicle is generated to a smaller side when the prediction process predicts that the temperature will rise.

[0119] When the fuel cut-off process is performed, the higher the speed of the crankshaft of the internal combustion engine relative to the speed of the drive wheel, the greater the deceleration can be. However, according to the fuel cut-off process, a large amount of oxygen flows into the filter, which easily causes the temperature of the filter to rise. In particular, when the speed is high when the filter process is performed, the amount of oxygen flowing into the filter per unit time becomes larger than when the speed is low. Therefore, due to the oxidation heat of the particulate matter captured by the filter, the temperature of the filter tends to become excessively high. Therefore, in the above-mentioned structure, when it is predicted that the temperature of the filter will exceed the allowable range and rise, the deceleration is limited to the small side. Thereby, the amount of oxygen flowing into the filter can be reduced, so that the excessive increase in the temperature of the filter can be suppressed.

[0120] Regarding the deceleration control process in the above supplementary note

[0121] It is not essential to use different maps for each gear. For example, a common map may be used for the D range and the B range. In this case, the minimum drive torque obtained by executing the combustion control of the internal combustion engine 10 may be set as the minimum value of the drive torque.

[0122] The deceleration control process is not limited to limiting the minimum value of the driving torque in each gear to the larger side. In other words, it is not limited to limiting the maximum value of the deceleration torque in each gear to the smaller side. For example, it may be a process that prohibits a gear such as the B gear where the driving torque is particularly small.

[0123] The deceleration control process is not limited to the process of executing combustion control of the internal combustion engine 10 and applying negative drive torque to the drive wheels 60. For example, the process of limiting the internal combustion engine speed NE to a smaller side may be used. This can also reduce the amount of oxygen flowing into the GPF 34 per unit time.

[0124] Regarding the prediction processing in the above supplementary note

[0125] The prediction process is not limited to the process of predicting based on the temperature Tgpf and the PM accumulation amount DPM at each time. For example, as described in the column "About Notification Processing", if the notification process is executed before the start of the vehicle VC, it may be set as a process of determining whether the FC possible time Tfc is less than the threshold value Tth before the start. In this case, the FC possible time Tfc may be calculated using, for example, only the PM accumulation amount DPM as an input. Alternatively, the PM accumulation amount DPM and the temperature at the start of the internal combustion engine 10 may be used as inputs to calculate. Moreover, for example, when the destination of the vehicle VC is set, a variable indicating the route to the destination may be included in the input. In this case, when the route to the destination is entirely in the urban area, it may be determined that the FC possible time Tfc is less than the threshold value Tth when the PM accumulation amount DPM is larger than when more downhill slopes are included.

[0126] Regarding the notification process in the above notes

[0127] ·exist Figure 3 , the content of informing the limited deceleration during the running of the vehicle VC is illustrated, but the present invention is not limited to this. For example, the informing process may be performed only before the vehicle VC starts. Specifically, for example, the informing process may be performed by switching the system main relay connecting the first converter 56 and the second converter 58 and the battery 59 to the closed state as a trigger.

Claims

1. A control device for a hybrid vehicle, the hybrid vehicle comprising an internal combustion engine and a rotating electrical machine, The internal combustion engine includes a filter in an exhaust passage configured to collect particulate matter in the exhaust gas. The control device comprises a processing circuit, The processing circuit is configured to execute a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process is a process of responding to a deceleration request of the hybrid vehicle by using a fuel cut process. The fuel cut process is a process of stopping the combustion control of the fuel in the cylinder of the internal combustion engine. The second deceleration control process is a process that responds to a deceleration request of the hybrid vehicle without utilizing the fuel cut process. The selection process is a process of selecting and executing the second deceleration control process when the PM accumulation amount is equal to or larger than a threshold value, and selecting and executing the first deceleration control process when the PM accumulation amount is smaller than the threshold value. The PM accumulation amount is the amount of particulate matter accumulated on the filter. The processing circuit is configured to perform a gradient process, The gradual change process is a process for gradually shifting to a deceleration achievable by the second deceleration control process in the first deceleration control process before switching to the second deceleration control process when the PM accumulation amount becomes equal to or larger than the threshold value during execution of the first deceleration control process.

2. The control device for a hybrid vehicle according to claim 1, wherein: The selection process includes a process of variably setting the threshold value according to the temperature of the filter, wherein the threshold value set when the temperature of the filter is high is equal to or less than the threshold value set when the temperature of the filter is low.

3. The control device for a hybrid vehicle according to claim 1, wherein: The hybrid vehicle includes a gear ratio adjustment device and an electric storage device. The crankshaft of the internal combustion engine is mechanically connected to the drive wheel via the speed ratio adjustment device. The speed ratio adjustment device is configured to adjust the ratio of the rotation speed of the crankshaft to the rotation speed of the drive wheel. The power storage device is configured to be charged by regenerative electric power of the rotating electric machine. The second deceleration control process includes a process of setting the regenerative power and the internal combustion engine speed according to the charging rate of the power storage device. The regenerative electric power set when the charging rate of the power storage device is high is equal to or less than the regenerative electric power set when the charging rate is low. The internal combustion engine speed set when the charging rate of the power storage device is high is equal to or higher than the internal combustion engine speed set when the charging rate is low.

4. The control device for a hybrid vehicle according to any one of claims 1 to 3, wherein: The processing circuit is configured to perform notification processing, The notification process is a process of notifying the user that the deceleration is limited to a smaller side before executing the second deceleration control process.

5. The control device for a hybrid vehicle according to any one of claims 1 to 3, wherein: The processing circuit is configured to execute the second deceleration control process in response to a deceleration request of the hybrid vehicle when there is a history of execution of the second deceleration control process within one trip even if the PM accumulation amount is smaller than the threshold value.

6. A control method for a hybrid vehicle, the hybrid vehicle comprising an internal combustion engine and a rotating electrical machine, The internal combustion engine includes a filter in an exhaust passage configured to collect particulate matter in the exhaust gas. The control method includes executing a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process is a process of responding to a deceleration request of the hybrid vehicle by using a fuel cut process. The fuel cut process is a process of stopping the combustion control of the fuel in the cylinder of the internal combustion engine. The second deceleration control process is a process that responds to a deceleration request of the hybrid vehicle without utilizing the fuel cut process. The selection process is a process of selecting and executing the second deceleration control process when the PM accumulation amount is equal to or larger than a threshold value, and selecting and executing the first deceleration control process when the PM accumulation amount is smaller than the threshold value. The PM accumulation amount is the amount of particulate matter accumulated on the filter. The control method includes performing a gradient process, The gradual change process is a process for gradually shifting to a deceleration achievable by the second deceleration control process in the first deceleration control process before switching to the second deceleration control process when the PM accumulation amount becomes equal to or larger than the threshold value during execution of the first deceleration control process.

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