Hybrid Electric Vehicle

Abstract

To enable an electric running mode to be automatically selected properly while reducing a feeling of strangeness of a user.SOLUTION: A control device of a hybrid electric vehicle is configured to execute running support control by which electric running and hybrid running are automatically switched on the basis of information on a route up to a destination. The hybrid electric vehicle includes, as an electric running mode in which the vehicle can run with electric power, a first electric running mode in which the vehicle runs with driving force generated by one or a plurality of electric motors without depending on operation amounts of an accelerator pedal and without activating an internal combustion engine and a second electric running mode in which the vehicle runs with driving force generated by one or the plurality of electric motors while temporarily activating the internal combustion engine in accordance with the operation amounts of the accelerator pedal. When switching the hybrid running to the electric running during execution of the running support control, the control device selects either of the first electric running mode and the second electric running mode, which has been selected by a user just before switching the mode.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to hybrid electric vehicles. [Background technology]

[0002] Patent Document 1 discloses a hybrid vehicle equipped with an electric motor and an engine that generate driving force for the vehicle. In this hybrid vehicle, the driving mode is automatically switched based on route information and vehicle position information. The driving mode is switched between at least two of an electric motor mode (electric driving) in which the vehicle runs only on the electric motor, an engine mode in which the vehicle runs only on the engine, and a combined mode (hybrid driving) in which the vehicle runs using both the electric motor and the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3169100 Summary of the Invention [Problem to be solved by the invention]

[0004] In a hybrid electric vehicle that can select from multiple electric driving modes to achieve electric driving using an electric motor, there is room for consideration as to which of the multiple electric driving modes to select in situations such as automatically switching from hybrid driving to electric driving.

[0005] The present disclosure has been made in consideration of the above-described problems, and its purpose is to enable appropriate automatic selection of an electric driving mode while reducing discomfort felt by the user in a hybrid electric vehicle that has multiple electric driving modes available. [Means for solving the problem]

[0006] A hybrid electric vehicle according to a first aspect of the present disclosure includes a powertrain and a control device. The powertrain is configured to be capable of hybrid driving and power generation through cooperation between an internal combustion engine and one or more electric motors, and electric driving using one or more electric motors without operating the internal combustion engine. The control device is configured to execute driving assistance control that automatically switches between electric driving and hybrid driving based on route information to a destination. The hybrid electric vehicle includes, as electric driving modes that achieve electric driving, a first electric driving mode in which the vehicle runs using the driving force of one or more electric motors without operating the internal combustion engine regardless of the amount of accelerator pedal operation, and a second electric driving mode in which the vehicle runs using the driving force of the one or more electric motors while temporarily operating the internal combustion engine in accordance with the amount of accelerator pedal operation. When switching from hybrid driving to electric driving while driving assistance control is being executed, the control device selects the first electric driving mode or the second electric driving mode, whichever was most recently selected by the user before the switch.

[0007] A hybrid electric vehicle according to a second aspect of the present disclosure includes a powertrain and a control device. The powertrain is configured to be able to perform hybrid driving and power generation through cooperation between an internal combustion engine and one or more electric motors, and electric driving using one or more electric motors without operating the internal combustion engine. The control device is configured to execute driving assistance control that automatically switches between electric driving and hybrid driving based on route information to a destination. The hybrid electric vehicle includes, as electric driving modes that achieve electric driving, a first electric driving mode in which the vehicle runs using the driving force of one or more electric motors without operating the internal combustion engine regardless of the amount of accelerator pedal operation, and a second electric driving mode in which the vehicle runs using the driving force of the one or more electric motors while temporarily operating the internal combustion engine in accordance with the amount of accelerator pedal operation. If the system of the hybrid electric vehicle is turned off while hybrid driving is selected during driving assistance control and then turned on again, the control device selects the first electric driving mode or the second electric driving mode, whichever was most recently selected by the user before the system was turned off. [Effects of the Invention]

[0008] According to the present disclosure, when there are two electric driving modes, a first electric driving mode and a second electric driving mode, that can be selected to suit the user's preferences, it is possible to appropriately automatically select the electric driving mode while reducing the sense of discomfort felt by the user. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a schematic configuration of a hybrid electric vehicle according to an embodiment. [Figure 2] 10A and 10B are diagrams for explaining a specific example of automatic switching of driving modes related to driving support control according to an embodiment. [Figure 3] 4 is a flowchart showing a process related to automatic switching of a driving mode related to driving support control according to an embodiment. [Figure 4] 10A and 10B are diagrams for explaining specific examples of switching between various driving modes and updating of the mode Ms. [Figure 5] 10 is a flowchart showing a process related to automatic switching of a driving mode related to driving support control according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] 1. Example of Hybrid Electric Vehicle (HEV) Configuration 1 is a diagram that schematically shows the configuration of a hybrid electric vehicle 1 according to an embodiment. The hybrid electric vehicle 1 includes a powertrain 10, a control device 20, and an HMI (Human Machine Interface) device 30. The control device 20 includes a vehicle control ECU (Electronic Control Unit) 22 and a navigation ECU (Navi ECU) 24.

[0012] The powertrain 10 includes an internal combustion engine 12, one or more (e.g., two) electric motors 14, and a battery 16, and is configured to perform hybrid driving (HEV driving) and power generation through cooperation between the internal combustion engine 12 and the electric motors 14, and electric driving (BEV driving) performed by the electric motors 14 without operating the internal combustion engine 12. The battery 16 exchanges electric power with the powertrain 10 (more specifically, the electric motors 14). Specifically, the battery 16 is charged by electric power generated by the electric motors 14 and discharged by electric power consumed by the electric motors 14. The hybrid system of the vehicle 1 is not particularly limited and may be, for example, a series-parallel system, a parallel system, or a series system. More specifically, the vehicle 1 is a plug-in hybrid electric vehicle (PHEV) that can be externally charged, but it does not necessarily have to be configured to be externally chargeable.

[0013] The vehicle control ECU 22 includes a processor and a storage device. The vehicle control ECU 22 receives sensor signals from sensors 26 attached to the vehicle 1 and outputs operation signals to the powertrain 10. The storage device stores various control programs for controlling the powertrain 10. The processor reads and executes the control programs from the storage device, thereby realizing various controls related to the powertrain 10. The sensors 26 include various sensors used to control the powertrain 10, such as a vehicle speed sensor, an accelerator position sensor, and a battery remaining capacity sensor. The accelerator position sensor detects the amount of accelerator pedal operation (depression amount). The battery remaining capacity sensor detects the remaining capacity (battery remaining capacity) of the battery 16. In the following description, the battery remaining capacity is also referred to as SOC (State Of Charge).

[0014] The navigation ECU 24 includes a processor and a storage device. The navigation ECU 24 is configured to be able to communicate with external systems via a wireless communication network, and can acquire various data from the external systems.

[0015] For example, the navigation ECU 24 acquires the current position of the vehicle 1 using a Global Navigation Satellite System (GNSS). Furthermore, the navigation ECU 24 can identify the current position of the vehicle 1 on a map by acquiring map information, for example, from an external server. The map information here includes information about specific areas SA where BEV driving (i.e., the internal combustion engine 12 is not in operation) is recommended, and geographical information (e.g., speed limits, distances, and road types). The specific areas SA are, for example, low-emission zones where driving of the vehicle 1 with the internal combustion engine 12 in operation is restricted. The specific areas SA may also be, for example, an area around the home of the user of the vehicle 1. The navigation ECU 24 can also acquire various types of traffic information, such as congestion information, regulation information, and traffic accident information, from a traffic information center. The navigation ECU 24 can notify the user of the vehicle 1 of such various information using the HMI device 30. The HMI device 30 includes, for example, an output unit and an input unit provided in the interior of the vehicle 1. The output unit may include a display unit such as a display of a navigation system or a meter installed on an instrument panel. The output unit may include a speaker. The input unit may be a touch panel or switches.

[0016] The navigation ECU 24 can also accept operations by the user via the HMI device 30. For example, when the user operates the HMI device 30 to input a destination, the navigation ECU 24 creates a planned driving route PR from the current position of the vehicle 1 to the destination, displays it on the HMI device 30, and provides route guidance. In addition, the specific area SA may be arbitrarily set by the user operating the HMI device 30, for example.

[0017] The navigation ECU 24 can also calculate the required traveling power PW required to travel each traveling section of the planned traveling route PR based on at least one of past traveling data and information such as the type of road surface or gradient included in the map information. The navigation ECU 24 can also calculate the required energy Esum required to travel the planned traveling route PR by integrating the required traveling power PW for the planned traveling route PR. In addition, the navigation ECU 24 can also calculate the required energy Eev required to travel a specific section X (described below) using BEV traveling.

[0018] The navigation ECU 24 is communicatively connected to the vehicle control ECU 22, for example, via CAN (Controller Area Network) communication. This allows the vehicle control ECU 22 to acquire various information (route information) including the above-mentioned planned travel route PR and various information related to the planned travel route PR from the navigation ECU 24. The route information here is information related to the route ahead of the vehicle that is read ahead, and is therefore hereinafter also referred to as "read-ahead information." More specifically, the read-ahead information includes information related to each travel section along the planned travel route PR. The read-ahead information includes, for example, the above-mentioned map information, traffic information, section vehicle speed, and required travel power PW.

[0019] 2. Vehicle driving control The control device 20 is configured to be able to execute "driving support control," which serves as a vehicle driving support function, automatically switching between BEV driving and HEV driving based on route information to the destination. More specifically, this driving support control appropriately manages the SOC of the battery 16 while the vehicle is driving by automatically switching between BEV driving and HEV driving. The appropriate management of the SOC here corresponds to, for example, managing the SOC so that the SOC is appropriately consumed in consideration of the overall driving load of the planned driving route PR based on route information (look-ahead information). The appropriate SOC management is performed, for example, so that the SOC is fully consumed in time for the vehicle 1 to arrive at the destination.

[0020] In the driving assist control, in order to appropriately manage the SOC, the control device 20 automatically selects BEV driving or HEV driving by automatically switching between a CD (Charge depleting) mode and a CS (Charge sustaining) mode. The CD mode is a mode in which the vehicle drives mainly using the electric power charged in the battery 16. The CS mode is a mode in which the internal combustion engine 12 and the electric motor 14 are operated so as to maintain the target SOC. More specifically, according to the driving assist control, based on the above-mentioned look-ahead information, for example, the CD mode is selected for low-load sections where engine efficiency is relatively low compared to the entire planned driving route PR, and the CS mode is selected for driving sections other than the low-load sections. As a result of this driving mode switching, BEV driving or HEV driving is automatically selected. For example, information such as the required driving power PW of each driving section, the length of the driving section, and the vehicle speed is used as look-ahead information for such driving mode selection. More specifically, for example, the CD mode is selected when the required driving power PW is less than a threshold, and the CS mode is selected when the required driving power PW is equal to or greater than the threshold.

[0021] 2-1. Examples of driving modes More specifically, the driving modes of the vehicle 1 are configured as follows: That is, the CD mode, which is an electric driving mode for realizing BEV driving, includes, for example, a "first BEV mode (first electric driving mode)" and a "second BEV mode (second electric driving mode)."

[0022] The first BEV mode is a mode in which the vehicle travels using the driving force of the electric motor 14 without operating the internal combustion engine 12, regardless of the amount of accelerator pedal operation. That is, in the first BEV mode, only BEV traveling is performed until the SOC is depleted.

[0023] The second BEV mode is a mode in which the internal combustion engine 12 is temporarily operated in accordance with the amount of accelerator pedal depression (more specifically, when the amount of accelerator pedal depression is large) while the vehicle is traveling using the driving force of the electric motor 14. That is, in the second BEV mode, the vehicle is basically traveling in BEV mode, but when the user requests high vehicle output, HEV mode is temporarily performed.

[0024] On the other hand, the CS mode, which is a hybrid driving mode for realizing HEV driving, includes a “first HEV mode” and a “second HEV mode.” Both the first and second HEV modes are modes for performing HEV driving while maintaining the SOC at a target value by utilizing power generation using the power of the internal combustion engine 12.

[0025] The first HEV mode is a mode in which the target value is the SOC value when the first HEV mode is selected. The second HEV mode is a mode in which the target value is set to a predetermined threshold value when the SOC falls below the threshold (when the battery is depleted). The second HEV mode is automatically selected by the control device 20, for example, when the SOC falls below the threshold while the CD mode (first or second BEV mode) is selected.

[0026] In addition to the CD mode and the CS mode, the driving modes of the vehicle 1 also include, for example, a charge mode. The charge mode is a mode in which, when the SOC is depleted, the vehicle 1 performs HEV driving to restore the SOC to a predetermined threshold value.

[0027] Of the various driving modes described above, the first and second BEV modes, the first HEV mode, and the charging mode can be selected by a user (for example, a driver) who operates the HMI device 30.

[0028] 2-2. Automatic switching of driving modes related to driving assistance control As described above, the driving assistance control automatically switches between the CD mode and the CS mode to automatically switch between the BEV driving and the HEV driving based on the route information. More specifically, the candidates for switching on the CD mode side are the first BEV mode and the second BEV mode. The candidate for switching on the CS mode side is the first HEV mode.

[0029] As mentioned above, there are two candidates for the CD mode side. Therefore, in driving assistance control, when the CS mode is selected and the vehicle is running in HEV driving, and the CD mode is selected to switch to BEV driving, there is room for consideration as to whether to select the first BEV mode or the second BEV mode.

[0030] Furthermore, when HEV driving is selected during driving assist control, the hybrid system of the vehicle 1 may be turned off and then turned on again (READY-ON). If there are two candidates for the CD mode as described above, there is room for consideration as to whether to select the first BEV mode or the second BEV mode when the hybrid system is turned on again.

[0031] 2 is a diagram for explaining a specific example of automatic switching of driving modes related to driving assist control according to an embodiment. Fig. 2 shows driving examples A to D of the vehicle 1 from the start point of driving assist control to the destination. According to the driving assist control, switching between BEV driving and HEV driving is performed so that the SOC is appropriately consumed while the vehicle is traveling.

[0032] In this embodiment, in view of the above-mentioned problems, when switching from HEV driving to BEV driving while driving assistance control is being executed, the control device 20 selects the first BEV mode or the second BEV mode that was most recently selected by the user of the vehicle 1 before the switching.

[0033] Specifically, in driving example A in Fig. 2, user U1 operates the HMI device 30 to select the first BEV mode before the start of driving assist control. As a result, the first BEV mode is selected as the CD mode at the start of driving assist control, as shown in Fig. 2. Then, when the driving mode is subsequently returned from the CS mode (first HEV mode) to the CD mode in response to a request from the driving assist control, the first BEV mode, which is the CD mode originally selected by user U1, is selected.

[0034] In driving example B, user U2 operates HMI device 30 to select the second BEV mode before the start of driving assist control. As a result, the second BEV mode is selected as the CD mode at the start of driving assist control, as shown in Fig. 2. Then, when the driving mode is subsequently returned from the CS mode to the CD mode in response to a request from the driving assist control, the second BEV mode, which is the CD mode originally selected by user U2, is selected.

[0035] In addition, in this embodiment, if the hybrid system of vehicle 1 is turned off when HEV driving is selected during driving assistance control and the hybrid system is then turned on, the control device 20 selects either the first BEV mode or the second BEV mode, whichever was most recently selected by the user of vehicle 1 before the hybrid system was turned off.

[0036] Specifically, in driving example C in Fig. 2, user U2 turns off the hybrid system while selecting the CS mode (first HEV mode). Then, the hybrid system is subsequently turned on, and driving assist control is resumed. According to this embodiment, when the driving mode returns from the CS mode to the CD mode following the resumption of driving assist control, the second BEV mode, which is the CD mode originally selected by user U2, is selected.

[0037] Furthermore, in this embodiment, when driving assistance control ends while HEV driving is selected, the control device 20 selects either the first BEV mode or the second BEV mode, whichever was most recently selected by the user of the vehicle 1 before the driving assistance control ended, as the electric driving mode (CD mode) after the driving assistance control ends.

[0038] Specifically, Fig. 2 shows an example of a condition for terminating cruise assist control, in which route guidance is stopped while the CS mode (first HEV mode) is selected, as driving example D. According to the present embodiment, in driving example D, the second BEV mode, which is the CD mode originally selected by user U2, is selected as the driving mode at the end of cruise assist control. Fig. 2 also shows an example of vehicle travel that is started in this manner with the second BEV mode selected and without cruise assist control.

[0039] 3 is a flowchart showing a process for automatically switching a driving mode related to driving support control according to the embodiment. The process of this flowchart is started when the hybrid system of the vehicle 1 is started (system ON). The process of this flowchart is executed by the control device 20 (more specifically, by cooperation between the vehicle control ECU 22 and the navigation ECU 24, for example).

[0040] 3, in step S100, the control device 20 determines whether the current driving mode of the vehicle 1 is the CD mode. As already described, the driving mode of the vehicle 1 can be selected by the user operating the HMI device 30. Furthermore, if driving assistance control is being executed, the driving mode is switched in accordance with a driving mode switching request (hereinafter also simply referred to as "mode request R") from the driving assistance control.

[0041] If the determination result in step S100 is Yes, the process proceeds to step S102. In step S102, the control device 20 updates the mode Ms with the current CD mode (that is, the first BEV mode or the second BEV mode).

[0042] More specifically, the mode Ms is stored in a storage device of the control device 20 (for example, a storage device of the navigation ECU 24) so ​​that the CD mode can be specifically identified when the driving mode is transitioned (returned) from the CS mode to the CD mode during or at the end of driving assist control. A specific example of updating the mode Ms will be described later with reference to Fig. 4. After step S102, the process proceeds to step S104.

[0043] On the other hand, if the determination result in step S100 is No, the process proceeds directly to step S104. That is, if the current driving mode is a mode other than the CD mode (the CS mode or the charge mode), the mode Ms is not updated. In other words, the mode Ms is maintained at the previous value.

[0044] Here, the start conditions for driving assist control are conditions that are met when driving assistance (SOC management) by the driving assist control can be started. The start conditions include, for example, that a switch requesting driving assist control is ON, that route guidance based on a request from a user has started, that the vehicle 1 is on the planned driving route PR, that the SOC is equal to or greater than a predetermined threshold, and that no abnormality has occurred in the vehicle 1. After the system is turned ON, when the start conditions for driving assist control are met, a mode request R is issued by the driving assist control.

[0045] In step S104, the control device 20 determines whether the mode request R from the driving support control is a request for the CD mode (BEV driving). If the determination result is Yes, the control device 20 selects the CD mode (first or second BEV mode) corresponding to the currently stored mode Ms in step S106. That is, in response to the mode request R from the driving support control, the driving mode of the vehicle 1 is transitioned to the CD mode corresponding to the mode Ms. Thereafter, the process proceeds to step S116.

[0046] On the other hand, if the determination result in step S104 is No, then in step S108, the control device 20 determines whether the mode request R is a request for the CS mode (HEV driving). If the determination result is Yes, then in step S110, the control device 20 selects the CS mode (more specifically, the first HEV mode). That is, in response to the mode request R, the driving mode of the vehicle 1 is transitioned to the CS mode. Thereafter, the process proceeds to step S116.

[0047] On the other hand, if the determination result in step S108 is No, the process proceeds to step S112. The mode request R is repeatedly output at a predetermined sampling period. In step S112, it is determined whether or not a mode request R was made in the previous sampling period. The process shown in FIG. 3 proceeds to step S112 if there is no mode request R in the current sampling period (No in both steps S102 and S108). Therefore, a Yes determination result in step S112 indicates that there is no longer a mode request R in the current sampling period, in other words, that the driving support control has ended. Conditions for ending the driving support control include, for example, that route guidance has been stopped or ended, that the vehicle 1 has deviated from the planned driving route PR, that the battery has run out, or that an abnormality has occurred in the vehicle 1.

[0048] If the determination result in step S112 is Yes, the control device 20 selects the CD mode (first or second BEV mode) corresponding to the currently stored mode Ms in step S114. That is, when the driving assist control ends, the driving mode of the vehicle 1 is transitioned to the CD mode corresponding to the mode Ms. Thereafter, the process proceeds to step S116.

[0049] On the other hand, if the determination result in step S112 is No, that is, if there has been no mode request R since the previous or previous sampling period, the process proceeds to step S116 without switching (transitioning) the driving mode.

[0050] In step S116, the control device 20 determines whether or not the battery is depleted. Specifically, if the SOC has dropped below a predetermined threshold, the determination result is Yes, and the control device 20 selects the second HEV mode in step S118. Thereafter, the process proceeds to step S120. Also, if the determination result in step S116 is No, the process proceeds to step S120.

[0051] In step S120, the control device 20 determines whether the user has performed an operation to stop the hybrid system of the vehicle 1. As a result, while the system OFF state is not established, the control device 20 repeatedly executes the processes from step S100 onwards. As a result, the mode Ms is updated as the user selects the first or second BEV mode. On the other hand, if the system OFF state is established, the control device 20 ends the process shown in FIG. 3.

[0052] FIG. 4 is a diagram for explaining a specific example of switching between various driving modes and updating the mode Ms.

[0053] In this embodiment, when the hybrid system is started (system ON) in the case where there is "remaining battery power" (i.e., when the SOC is equal to or greater than a predetermined threshold), the control device 20 selects the first BEV mode or the second BEV mode, as shown in FIG.

[0054] More specifically, the first BEV mode is generally automatically selected when the system is ON, unless the system is turned ON after being turned OFF during route guidance using cruise assist control. In this embodiment, such automatic selection of the first BEV mode when the system is ON is considered to be selection of the first BEV mode by the user. As a result, in step S102 of FIG. 3, mode Ms is updated to the first BEV mode.

[0055] On the other hand, if the system is turned off during route guidance using cruise assist control and then turned on again, the CD mode (either the first or second BEV mode) selected by the user before the system was turned off is automatically selected when the system is turned on, as shown in FIG. 4. In this embodiment, such automatic selection of the CD mode when the system is on is also considered to be a selection of the CD mode by the user. Then, in step S102, the mode Ms is updated to the first or second BEV mode in accordance with this selection. Therefore, according to the processing of the flowchart shown in FIG. 3, if the system is turned off during route guidance and then turned on again, the CD mode (either the first or second BEV mode) selected by the user before the system was turned off is selected.

[0056] After the first BEV mode is selected when the system is turned on, the second BEV mode, the charge mode, or the first HEV mode may be selected by a user operation, as shown in Fig. 4. In this case, the mode Ms is updated when the second BEV mode is selected, but is not updated when the charge mode or the first HEV mode is selected. Also, after the first BEV mode is selected when the system is turned on, the first HEV mode may be selected in response to a mode request R from the driving support control, or the second HEV mode may be selected due to battery depletion, as shown in Fig. 4. However, the mode Ms is not updated even when the first BEV mode or the second HEV mode is selected in this way.

[0057] The same applies to the case after the second BEV mode is selected when the system is turned on. That is, the mode Ms is updated only when the first BEV mode is selected by a user operation after the second BEV mode is selected when the system is turned on.

[0058] The bottom part of FIG. 4 shows an example in which the system is turned on when a "battery exhaustion" condition occurs. In this example, the second HEV mode is automatically selected by the control device 20. Then, in this example, when the SOC subsequently recovers, the first BEV mode is automatically selected. In this embodiment, this automatic selection of the first BEV mode when the SOC recovers is also considered to be a selection of the first BEV mode by the user. As a result, the mode Ms is updated to the first BEV mode.

[0059] Unlike the example shown in FIG. 4, when the system is ON, the first BEV mode may be automatically selected regardless of whether the system has been turned OFF during route guidance using driving assist control.

[0060] As described above, according to this embodiment, when switching from HEV driving to BEV driving while driving assist control is being executed, the first BEV mode or the second BEV mode, whichever was most recently selected by the user of the vehicle 1 before the switching, is selected. This allows for switching to a CD mode (electric driving mode) that matches the user's preferences when there are two options. In other words, it becomes possible to appropriately automatically select the BEV mode while reducing the user's sense of discomfort.

[0061] Furthermore, according to this embodiment, if the hybrid system is turned off when HEV driving is selected during driving assist control and the hybrid system is then turned on, the first BEV mode or the second BEV mode, whichever was most recently selected by the user of the vehicle 1 before the hybrid system was turned off, is selected. This allows for mode selection that matches the user's preferences when there are two options for the CD mode when driving assist control is resumed. In other words, it is possible to appropriately automatically select the BEV mode while reducing the user's discomfort.

[0062] Furthermore, according to this embodiment, when the driving assist control is terminated while HEV driving is selected, the first BEV mode or the second BEV mode, whichever was most recently selected by the user before the driving assist control was terminated, is selected as the electric driving mode (CD mode) after the driving assist control is terminated. This allows for mode selection that matches the user's preference when there are two options for returning the driving mode to the CD mode following the termination of driving assist control. In other words, the BEV mode can be appropriately selected automatically while reducing the user's discomfort.

[0063] 3. Mode selection taking into account driving sections where electric driving is recommended The "driving assistance control" that automatically switches between BEV driving and HEV driving based on route information to the destination may include control that automatically switches the driving mode to perform BEV driving in a specific section X, which is a driving section where BEV driving is recommended. More specifically, this control may manage the SOC by switching between BEV driving and HEV driving so that the SOCev required to travel the specific section X in BEV driving is secured before entering the specific section X, for example, when the "specific section X" is present on the planned driving route PR of the vehicle 1 to the destination. The specific section X is a driving section on the planned driving route PR that is included in the above-mentioned specific area SA. The required SOCev is the SOC value corresponding to the above-mentioned required energy Eev.

[0064] Furthermore, when BEV driving is performed in the above-mentioned specific section X, the control device 20 may select the first BEV mode for BEV driving in the specific section X, regardless of whether the first BEV mode or the second BEV mode is selected by the user. In other words, in the specific section X, the first BEV mode, which allows pure BEV driving without operating the internal combustion engine 12, may be selected.

[0065] 5 is a flowchart showing a process for automatically switching the driving mode related to driving support control according to a modified example of the embodiment. The differences between the process shown in this flowchart and the process shown in FIG.

[0066] 5, prior to the processing of step S116, in step S200, the control device 20 determines whether the current position of the vehicle 1 is within the specific section X. If the result of this determination is Yes, the control device 20 selects the first BEV mode in step S202. That is, even if the second BEV mode is selected as the CD mode corresponding to mode Ms in step S106, the first BEV mode is ultimately selected instead of the second BEV mode. On the other hand, if the result of the above determination is No, the processing proceeds directly to step S116.

[0067] According to the process shown in FIG. 5 described above, it is possible to basically select a mode that matches the user's preferences, while also performing appropriate BEV driving in consideration of the characteristics of the specific section X.

[0068] In addition, when the process shown in FIG. 5 is executed, the selection (transition) of the driving mode after passing through the specific section X may be executed, for example, as follows.

[0069] That is, after passing through the specific section X, the control device 20 may continue the first BEV mode until the user newly selects the second BEV mode. This prevents the BEV mode from being changed when passing through the specific section X, thereby suppressing discomfort felt by the user.

[0070] Alternatively, the control device 20 may change the mode to the CD mode originally selected by the user after passing through the specific section X. This allows the user's intention to be more faithfully reflected in the mode selection after passing through the specific section when the CD mode originally selected by the user is the second BEV mode. [Explanation of symbols]

[0071] 1 Hybrid electric vehicle, 10 Power train, 12 Internal combustion engine, 14 Electric motor, 20 Control device, 26 Sensors, 30 HMI device

Claims

1. a powertrain capable of hybrid driving and power generation through cooperation between an internal combustion engine and one or more electric motors, and electric driving performed by the one or more electric motors without operating the internal combustion engine; a control device that executes driving assistance control to automatically switch between the electric driving and the hybrid driving based on route information to a destination; A hybrid electric vehicle comprising: The electric traveling modes for realizing the electric traveling include a first electric traveling mode in which the vehicle travels using the driving force of the one or more electric motors without operating the internal combustion engine regardless of the amount of depression of the accelerator pedal, and a second electric traveling mode in which the vehicle travels using the driving force of the one or more electric motors while temporarily operating the internal combustion engine in accordance with the amount of depression of the accelerator pedal, When the system of the hybrid electric vehicle is turned off while the hybrid traveling mode is selected during the running assist control and the system is then turned on, the control device selects the mode selected by the user most recently before the system was turned off, from the first electric traveling mode and the second electric traveling mode. Hybrid electric vehicle.

2. When the driving assist control is terminated while the hybrid driving is selected, the control device selects, as the electric driving mode after the driving assist control is terminated, one of the first electric driving mode and the second electric driving mode that was most recently selected by the user before the driving assist control was terminated.

10. The hybrid electric vehicle of claim 1.

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