Hybrid vehicles

Abstract

To achieve high energy efficiency in a hybrid vehicle.SOLUTION: A hybrid vehicle is equipped with a control device that can selectively execute a plurality of travelling modes. The plurality of travelling modes includes an EV-travelling mode, a normal HV-travelling mode and a charging HV-travelling mode in which a battery is charged more than in the normal HV-travelling mode. Processing for generating plan data on the travelling modes that are executed by the control device includes first processing and second processing. In the first processing, the EV-travelling mode is allocated to at least one of a plurality of sections, until sum of required travelling energy reaches residual amounts of charge of the battery, and the normal HV-travelling mode is allocated to the other sections. In the second processing, when there is a low-load section in the sections to which the normal HV-travelling mode is allocated, at least one of the normal HV-travelling mode allocated to a high-load section positioned nearer to a front side than the low-load section is changed to the charging HV-travelling mode.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to hybrid vehicles. [Background technology]

[0002] Patent Document 1 describes a hybrid vehicle. This hybrid vehicle is equipped with a motor and engine for driving, a battery that can be charged and discharged by the motor, and a control device that controls the motor and engine to selectively execute an EV driving mode or an HV driving mode. The EV driving mode is a driving mode in which the vehicle runs on the motor while the engine is stopped, and the HV driving mode is a mode in which the vehicle runs on the engine and / or the motor while the engine is operating.

[0003] The control device described above obtains a predicted driving route to the destination, and calculates the required driving energy for each of a plurality of sections of the predicted driving route. The control device assigns the EV driving mode until the sum of the required driving energies exceeds the remaining charge of the battery, and creates driving mode plan data in which the HV driving mode is assigned to the remaining sections. Based on this driving mode plan data, the control device selectively executes either the EV driving mode or the HV driving mode, thereby realizing high energy efficiency (so-called high fuel efficiency) of the hybrid vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-151760 A Summary of the Invention [Problem to be solved by the invention]

[0005] When creating the driving mode plan data, it is advisable to assign the EV driving mode to low-load sections where the driving load is relatively low, and the HV driving mode to high-load sections where the driving load is relatively high. However, when the remaining charge of the battery is relatively low, it is not possible to assign the EV driving mode to all low-load sections included in the predicted driving route. In this case, the HV driving mode is assigned to some low-load sections. As a result, there is a risk of reducing the energy efficiency of the hybrid vehicle.

[0006] In view of the above circumstances, this specification provides a technique for achieving high energy efficiency in hybrid vehicles. [Means for solving the problem]

[0007] The technology disclosed in this specification is embodied in a hybrid vehicle. The hybrid vehicle includes a motor and an engine for driving, a battery that supplies driving power to the motor and is charged with power generated by the motor, and a control device configured to be able to control the motor and the engine and capable of selectively executing a plurality of driving modes. The plurality of driving modes include at least an EV driving mode in which the vehicle runs on the motor while the engine is stopped, a normal HV driving mode in which the vehicle runs on the engine and / or the motor while the engine is operating, and a charging HV driving mode in which the vehicle runs on the engine and / or the motor while the engine is operating and the amount of charge to the battery is increased compared to the normal HV driving mode. While the hybrid vehicle is traveling on a predicted traveling route, the control device repeatedly executes a process of creating driving mode plan data describing one of the plurality of driving modes for each of a plurality of sections constituting the predicted traveling route, and a process of selectively executing the plurality of driving modes based on the driving mode plan data.

[0008] The process of creating the travel mode plan data includes a process of acquiring the predicted travel route and a process of identifying a required travel energy required for traveling each of the multiple sections of the predicted travel route. The process of creating the travel mode plan data further includes a first process and a second process. In the first process, the EV travel mode is assigned to at least one of the multiple sections until the sum of the required travel energy reaches the remaining charge amount of the battery, and the normal HV travel mode is assigned to the remaining sections of the multiple sections. In the second process, when a low-load section that satisfies a predetermined condition exists among the sections to which the normal HV travel mode is assigned, at least one of the normal HV travel modes that is assigned to a high-load section that is located before the low-load section and satisfies the predetermined condition is changed to a charging HV travel mode.

[0009] According to the above configuration, while the hybrid vehicle is traveling along the predicted travel route, a process of creating travel mode plan data and a process of selecting a travel mode based on the travel mode plan data are repeatedly executed. In the process of creating the travel mode plan data, the control device assigns the EV travel mode to at least one section until the sum of the required travel energy reaches the remaining charge of the battery, and assigns the normal HV travel mode to the other sections. Therefore, for example, when the remaining charge of the battery is relatively low, the normal HV travel mode may be assigned to some low-load sections. In this case, the control device refers to the other sections to which the normal HV travel mode is assigned, and when there is a high-load section located before the low-load section, changes the normal HV travel mode assigned to the high-load section to the charging HV travel mode. Thereafter, when the hybrid vehicle travels through the high-load section changed to the charging HV travel mode, the remaining charge of the battery increases. As a result, when the process of creating the travel mode plan data is executed again, the normal HV travel mode assigned to the low-load section is changed to the EV travel mode. As described above, even when the battery's remaining charge is relatively low, the EV driving mode can be selected more reliably in low load sections by increasing the remaining charge in the battery in high load sections, thereby achieving high energy efficiency in hybrid vehicles. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic external view of a vehicle 10. FIG. [Diagram 2] 1 is a block diagram showing the main configuration of a vehicle 10. [Diagram 3] 4 is a flowchart showing an example of a series of control operations executed by the hybrid ECU 22. [Figure 4]Fig. 4(A) shows the remaining charge of the battery 20 at each point on the predicted driving route PR. Fig. 4(B) is a diagram explaining driving mode plan data in which either the EV driving mode (denoted as "EV") or the normal HV driving mode (denoted as "NHV") is assigned to each section based on the sum of the required driving energy EE and the remaining charge of the battery 20. In addition, it also shows whether each section corresponds to a low load section LS or a high load section HS. [Diagram 5] The solid line in Fig. 5(A) indicates the remaining charge of the battery 20 at each point on the predicted driving route PR before the driving mode plan data is changed, and the dashed line in Fig. 5(B) indicates the estimated value of the remaining charge of the battery 20 at each point on the predicted driving route PR after the driving mode plan data is changed. Fig. 5(B) is a diagram explaining that the normal HV driving mode assigned to the high load section HS located before the low load section LS in the driving mode plan data is changed to the charging HV driving mode (denoted as "CHV"). In addition, it is also shown whether each section corresponds to the low load section LS or the high load section HS. [Figure 6] The solid lines in FIG. 6(A) indicate the remaining charge of the battery 20 at each point on the predicted driving route PR. As a comparative example, FIG. 4(A) is shown with dotted lines. FIG. 6(B) is a diagram for explaining that the normal HV driving mode assigned to the low load section LS is changed to the EV driving mode when the process for creating the driving mode plan data is executed again. In addition, it is also shown whether each section corresponds to the low load section LS or the high load section HS. Here, the hatched parts in FIG. 6(A) and (B) indicate the parts where the vehicle 10 has traveled. Therefore, in FIG. 6(A) and (B), the vehicle 10 is located at point P at the time when it has finished traveling the fourth section L4. [Figure 7] 4 is a flow diagram showing steps S22A-S22D which are a modification of step S22 in FIG. 3. [Figure 8] 4 is a flowchart showing steps S16A-S16E which are a modification of step S16 in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In one embodiment of the present technology, in the second process, a section in which the driving mode is changed to the charging HV driving mode may be added until an estimated value of the charge increase amount by which the battery is charged by changing to the charging HV driving mode exceeds the required driving energy of the low-load section to which the normal HV driving mode is assigned. With this configuration, the charge increase amount by which the battery is charged by changing to the charging HV driving mode can be used as energy for driving in the EV driving mode in the low-load section. This allows the normal HV driving mode assigned to the low-load section to be changed to the EV driving mode. Therefore, the section in which the driving mode is changed to the charging HV driving mode can be appropriately set according to the required driving energy of the low-load section.

[0012] In one embodiment of the present technology, in the second process, when there are multiple high load sections to which the normal HV driving mode is assigned before a low load section to which the normal HV driving mode is assigned, the driving mode may be changed to the charging HV driving mode in the order of the driving load from highest to lowest. Since the engine output is relatively high in sections with high driving loads, the charging HV driving mode is preferentially assigned to such sections, thereby enabling efficient charging of the battery.

[0013] In one embodiment of the present technology, the predetermined conditions defining the low load section may include at least one of a narrow street, a congested road, a congested road, and a required driving power below a predetermined lower limit. In this way, the predetermined conditions defining the low load section may be defined not only by a numerical index such as the required driving power, but also by road type information, congestion status, etc. The required driving power may be a value estimated based on past driving data, or may be a value estimated based on map information.

[0014] In one embodiment of the present technology, the predetermined conditions defining the high load section may include at least one of the following: that the road is an expressway, that the road is not congested, and that the required driving power exceeds a predetermined upper limit. In this way, the predetermined conditions defining the low load section may be defined not only by a numerical index such as the required driving power, but also by road type information, traffic congestion status, and the like.

[0015] In one embodiment of the present technology, in the charging HV traveling mode, a target lower limit value of the remaining charge amount of the battery may be set to a value greater than the remaining charge amount at the start of the charging HV traveling mode. With this configuration, the remaining charge amount of the battery can be reliably increased by executing the charging HV traveling mode.

[0016] In one embodiment of the present technology, in the charging HV traveling mode, the upper limit of the remaining charge amount of the battery may be invalidated. According to such a configuration, by executing the charging HV traveling mode, the remaining charge amount of the battery can be significantly increased.

[0017] In one embodiment of the present technology, in the first process, when the predicted driving route passes through a predetermined EV priority area, the EV driving mode may be assigned preferentially to an EV priority section included in the EV priority area. The EV priority area here includes, for example, a downhill section. With this configuration, the EV driving mode can be more reliably assigned to the EV priority section included in the EV priority area, and the energy efficiency of the hybrid vehicle can be further improved. In addition to or instead of the above, the EV priority area may include an urban area where driving of vehicles with engine operation is restricted, such that the EV driving mode is mandatory or strongly recommended.

[0018] In one embodiment of the present technology, in the first process, the EV driving mode may be assigned preferentially to sections with low driving loads. With this configuration, it is possible to further improve the energy efficiency of the hybrid vehicle.

[0019] A hybrid vehicle 10 (hereinafter, referred to as "vehicle 10") of this embodiment will be described with reference to the drawings. The vehicle 10 of this embodiment belongs to an electric vehicle having a motor 18 that drives wheels 14f, 14r, and is typically an electric vehicle (so-called automobile) that runs on a road surface. However, some or all of the techniques described in this embodiment can also be adopted in an electric vehicle that runs on a track. In addition, the vehicle 10 is not limited to one that is driven and operated by a user, but may be one that is remotely operated by an external device or one that runs autonomously.

[0020] Here, the direction FR in the drawings indicates the front in the fore-aft direction of the vehicle 10, and the direction RR indicates the rear in the fore-aft direction of the vehicle 10. Furthermore, the direction LH indicates the left in the left-right direction of the vehicle 10, and the direction RH indicates the right in the left-right direction of the vehicle 10. Furthermore, the direction UP indicates the upward direction in the vertical direction of the vehicle 10, and the direction DW indicates the downward direction in the vertical direction of the vehicle 10. Note that in this specification, the fore-aft direction of the vehicle 10, the left-right direction of the vehicle 10, and the up-down direction of the vehicle 10 may be simply referred to as the fore-aft direction, the left-right direction, and the up-down direction, respectively.

[0021] As shown in FIG. 1, the vehicle 10 includes a body 12 and a plurality of wheels 14f, 14r. The body 12 has a passenger compartment 12c, which is a space for carrying passengers. The plurality of wheels 14f, 14r are rotatably attached to the body 12. The plurality of wheels 14f, 14r include a pair of front wheels 14f located at the front of the body 12 and a pair of rear wheels 14r located at the rear of the body 12. The pair of front wheels 14f are arranged coaxially with each other, and the pair of rear wheels 14r are also arranged coaxially with each other. The number of wheels 14f, 14r is not limited to four. Although not particularly limited, the body 12 is made of a metal such as a steel material or an aluminum alloy.

[0022] As shown in FIGS. 1 and 2, the vehicle 10 further includes an engine 16 and a motor 18. The engine 16 is a heat engine, such as a gasoline engine or a diesel engine, that generates power by burning fuel. The engine 16 is connected to a pair of front wheels 14f and can drive the pair of front wheels 14f. The motor 18 is connected to the engine 16 via a power transmission path. The motor 18 is located between the engine 16 and the pair of front wheels 14f and can function as a prime mover that drives the pair of front wheels 14f together with the engine 16. The motor 18 can also function as a generator in addition to the prime mover. That is, the vehicle 10 can generate power by the motor 18 by driving the motor 18 with the engine 16. Alternatively, when the vehicle 10 needs to decelerate, for example, on a downhill slope, the motor 18 can function as a generator to perform regenerative braking of the pair of front wheels 14f. Note that a reduction gear or a clutch may be provided in the power transmission path between the engine 16 and the pair of front wheels 14f as necessary. Further, the engine 16 and the motor 18 are not limited to driving the pair of front wheels 14f, but may be configured to drive at least one of the multiple wheels 14f, 14r.

[0023] As shown in Fig. 1, the vehicle 10 further includes a battery 20. The battery 20 has a plurality of built-in secondary battery cells and is configured to be repeatedly chargeable by external power. The battery 20 is connected to the motor 18 via a power conversion device (not shown) and can supply driving power to the motor 18, and can also be charged by power generated by the motor 18. Although not limited to this, the battery 20 may be a lithium ion battery, a nickel metal hydride battery, or the like.

[0024] As shown in FIGS. 1 and 2, the vehicle 10 further includes a hybrid ECU (Electronic Control Unit) 22. The hybrid ECU 22 is a computer device having a processor, a memory, and the like. The hybrid ECU 22 is communicatively connected to the engine 16 and the motor 18 and is configured to be able to control the operations of these. For example, operation information by a user and vehicle information indicating the state of the vehicle 10 are input to the hybrid ECU 22. The operation information is, for example, accelerator opening information indicating the amount of operation of an accelerator pedal by the user and brake depression force information indicating the amount of brake operation by the user. The vehicle information is, for example, vehicle speed information indicating the speed of the vehicle 10 and battery information indicating the remaining charge amount of the battery 20. The hybrid ECU 22 controls the operation of each part of the vehicle 10 described above according to the input operation information and vehicle information.

[0025] The hybrid ECU 22 can selectively execute a plurality of driving modes including an EV driving mode and an HV driving mode. The EV driving mode is a driving mode in which the vehicle 10 drives using the motor 18 while the engine 16 is stopped. On the other hand, the HV driving mode is a driving mode in which the vehicle 10 drives using the engine 16 and / or the motor 18 while the engine 16 is in operation. The HV driving modes further include a normal HV driving mode and a charging HV driving mode. In the charging HV driving mode, the operation of the engine 16 and the motor 18 is controlled so that the amount of charge to the battery 20 is greater than in the normal HV driving mode. For example, in the charging HV driving mode, the power output by the engine 16 is supplied to the pair of front wheels 14f to drive the vehicle 10, and the power output by the engine 16 is also supplied to the motor 18, so that the battery 20 is charged by the power generated by the motor 18.

[0026] As one example, while the charging HV traveling mode is being executed, the hybrid ECU 22 can set a target lower limit value of the remaining charge amount of the battery 20 to a value greater than the remaining charge amount at the start of the charging HV traveling mode. As a result, by executing the charging HV traveling mode, the amount of charge to the battery 20 can be increased compared to when the normal HV traveling mode is being executed. In addition to this, or instead, while the charging HV traveling mode is being executed, the hybrid ECU 22 can disable the upper limit value of the remaining charge amount of the battery 20. As a result, by executing the charging HV traveling mode, the amount of charge to the battery 20 can be increased.

[0027] As shown in FIGS. 1 and 2, the vehicle 10 further includes a navigation system ECU (Electronic Control Unit) 24 (hereinafter, referred to as the "navigation ECU 24"). The navigation ECU 24 is a computer device having a processor, a memory, and the like. The navigation ECU 24 is configured to be able to communicate with an external system via the Internet or the like, and can acquire various information from the external system. For example, the navigation ECU 24 can acquire the current position of the vehicle 10 from a GPS (Global Positioning System). Furthermore, the navigation ECU 24 can specify the current position of the vehicle 10 on the map information by acquiring map information from an external server or the like. The map information here includes information on nodes such as intersections and branching points, and links that are sections between one node and another node. Furthermore, the map information includes position information of each node, distance information of each link, road type information included in each link (for example, information on a narrow street, an expressway, a general road, and the like), gradient information of each link (for example, uphill, downhill), speed limit information of each link, and the like. Although not limited thereto, the map information may further include information regarding specific areas in which the traveling of the vehicle 10 with the engine 16 in operation is restricted, and such specific areas may be designated in specific urbanized areas or may be temporarily designated depending on the time period, traffic conditions, etc., for the purpose of reducing environmental load. The navigation ECU 24 can also obtain congestion information, regulation information, traffic accident information, etc., from a traffic information center such as a VICS (registered trademark) (Vehicle Information and Communication System) center. The navigation ECU 24 can display such various information on a display 26 of a navigation system provided in the passenger compartment 12c.

[0028] In addition to the above, the navigation ECU 24 can accept an operation by a user via the display 26. For example, when a user inputs a destination on the display 26, the navigation ECU 24 creates a predicted driving route PR from the current position of the vehicle 10 to the destination, and displays the predicted driving route PR on the display 26. As described above, the map information includes information on each link, and the predicted driving route PR is created by connecting a plurality of links. Note that the navigation ECU 24 does not necessarily need to create the predicted driving route PR based on the destination input by the user. As an example, the navigation ECU 24 may create a predicted driving route PR along which the vehicle 10 is estimated to travel based on past driving data.

[0029] The navigation ECU 24 can also calculate the required driving power EP required to travel each link of the predicted travel route PR based on the past travel data and / or the road type information and gradient information of each link included in the map information. In this way, the required driving power EP is a value estimated based on the past travel data and / or the map information. In addition, the navigation ECU 24 can also calculate the required driving energy EE required to travel each link by integrating the required driving power EP for each link. Furthermore, the navigation ECU 24 can determine whether or not there is a low load section LS that satisfies a predetermined requirement and a high load section HS that satisfies a predetermined requirement in the predicted travel route PR based on the required driving power EP, road type information, congestion information, and the like of each link included in the map information. Here, the predetermined condition that defines the low load section LS includes at least one of a narrow street, a congested road, a congested road, and the required driving power EP being below a predetermined lower limit value. The predetermined conditions that define the high load section HS include at least one of the following: that the road is an expressway, that the road is not congested, and that the required driving power EP exceeds a predetermined upper limit. In this way, the predetermined conditions that define each of the low load section LS and the high load section HS can be determined not only by a numerical index such as the required driving power EP, but also by road type information, traffic congestion conditions, and the like.

[0030] The navigation ECU 24 is communicatively connected to the hybrid ECU 22 via CAN (Controller Area Network) communication. This allows the hybrid ECU 22 to acquire various information from the navigation ECU 24, including the above-mentioned predicted travel route PR, the required travel power EP for each link, the required travel energy EE, and information on the low load section LS and the high load section HS. Using the various information acquired from the navigation ECU 24, the hybrid ECU 22 can create travel mode plan data that describes one of a plurality of travel modes for each of the plurality of links that constitute the predicted travel route PR of the vehicle 10. Based on the travel mode plan data, the hybrid ECU 22 is configured to selectively execute a plurality of travel modes.

[0031] It should be noted that the hybrid ECU 22 does not necessarily need to obtain the required traveling power EP and the required traveling energy EE individually for each of all links. As will be described in detail later, the hybrid ECU 22 is configured to integrate a series of links having a common attribute, such as a road type, into one section when processing the predicted traveling route PR. Therefore, in another embodiment, the hybrid ECU 22 may obtain the required traveling power EP and the required traveling energy EE for each series of links constituting one section. In this case, the hybrid ECU 22 may also obtain information on whether each series of links constituting one section belongs to a low load section LS or a high load section HS.

[0032] A specific example of the operation of the vehicle 10, which is a control operation executed by the hybrid ECU 22, will be described with reference to Fig. 3. In this control operation, the hybrid ECU 22 supports the user in driving the vehicle 10 in a fuel-efficient manner by automatically switching the driving mode for the predicted driving route PR created by the navigation ECU 24. The hybrid ECU 22 is configured to execute the control operation shown in Fig. 3 in response to, for example, an instruction or operation by the user.

[0033] First, in step S10, the hybrid ECU 22 determines whether or not a predicted driving route PR has been created. As described above, the predicted driving route PR is created by the navigation ECU 24 based on a destination designated by the user and past driving data. This predicted driving route PR includes various information related to the predicted driving route PR, such as distance information, road type information, gradient information, speed limit information, congestion information, regulation information, and traffic accident information, which the navigation ECU 24 acquires from an external server or a traffic information center. When the navigation ECU 24 newly creates a predicted driving route PR in response to, for example, an instruction or operation by the user, the navigation ECU 24 transmits a predetermined notification to the hybrid ECU 22. When the hybrid ECU 22 receives the notification from the navigation ECU 24 (YES in step S10), the hybrid ECU 22 proceeds to processing in step S12.

[0034] In step S12, the hybrid ECU 22 acquires the predicted travel route PR from the navigation ECU 24. Next, the hybrid ECU 22 divides the predicted travel route PR into a plurality of sections, and specifies the required travel energy EE required to travel each section (step S14). As described above, the predicted travel route PR taught by the navigation ECU 24 is composed of a plurality of links. The hybrid ECU 22 divides the predicted travel route PR into a plurality of sections by integrating a series of links having a common attribute, such as a road type, into one section. This can reduce the calculation load of the hybrid ECU 22 compared to processing the plurality of links as they are. In addition, the predicted travel route PR includes information on the required travel power EP and required travel energy EE for each link, the low load section LS, and the high load section HS, and the like. Therefore, the hybrid ECU 22 can specify the required travel energy EE required to travel each section.

[0035] In step S16, the hybrid ECU 22 executes a first process of assigning either the EV driving mode or the normal HV driving mode to each of the multiple sections of the predicted travel route PR. In detail, the EV driving mode is assigned to at least one of the multiple sections until the sum of the required travel energy EE determined in step S14 reaches the remaining charge amount of the battery 20. At this time, the normal HV driving mode is assigned to the remaining sections of the predicted travel route PR. In this manner, the driving mode plan data is created by the first process.

[0036] When the travel mode plan data is created, the EV travel mode may be assigned to the low-load section LS where the travel load is relatively low, and the HV travel mode may be assigned to the high-load section HS where the travel load is relatively high. In this regard, in the first process, for example, the EV travel mode is assigned to the section where the travel load is low. However, as shown in Figs. 4(A) and 4(B), when the sum of the required travel energy EE of the multiple sections L1, L3, L5-L7, and L9, which are the low-load sections LS, exceeds the remaining charge amount of the battery 20, the EV travel mode is assigned only to some of the sections L1, L3, L5, L7, and L9. In this case, the normal HV travel mode is assigned to the remaining sections L2, L4, L6, and L8. As a result, the normal HV travel mode is assigned to the sixth section L6, which is the low-load section LS. For ease of explanation, the number of sections that make up the predicted driving route PR from the start point S to the end point G is set to nine, but the number of sections that make up the predicted driving route PR from the start point S to the end point G is not particularly limited.

[0037] Therefore, in step S18, the hybrid ECU 22 determines whether or not a low load section LS exists among the sections to which the normal HV driving mode is assigned. If the answer is YES in step S18, the hybrid ECU 22 proceeds to the process of step S20. In this embodiment, as shown in FIG. 4(B), the normal HV driving mode is assigned to the sixth section L6, and the sixth section L6 is a low load section LS, so the answer is YES in step S18. If the answer is NO in step S18, the hybrid ECU 22 selectively executes a driving mode based on the driving mode plan data created in the first process of step S16 (step S24).

[0038] In step S20, the hybrid ECU 22 determines whether or not there is a high load section HS that is located before the low load section LS to which the normal HV driving mode is assigned and is also assigned to the normal HV driving mode. If the answer is YES in step S20, the hybrid ECU 22 proceeds to the process of step S22. In this embodiment, as shown in FIG. 4(B), the second section L2 and the fourth section L4 are located before the sixth section L6, which is the low load section LS to which the normal HV driving mode is assigned, and correspond to the high load section HS to which the normal HV driving mode is assigned, so that the answer is YES in step S20. If the answer is NO in step S20, the hybrid ECU 22 selectively executes the driving mode based on the driving mode plan data created in the first process of step S16 (step S24).

[0039] In step S22, the hybrid ECU 22 executes a second process to change at least one of the normal HV driving modes assigned to the second section L2 and the fourth section L4 to the charging HV driving mode. That is, in this second process, at least one of the normal HV driving modes assigned to the high load section HS located before the low load section LS, which is determined to exist in step S18, is changed to the charging HV driving mode. Therefore, in this embodiment, at least one of the normal HV driving modes assigned to the second section L2 and the fourth section L4 is changed to the charging HV driving mode. Although not particularly limited, as shown in FIG. 5(B), both of the normal HV driving modes assigned to the second section L2 and the fourth section L4 can be changed to the charging HV driving mode. Thereafter, it is predicted that the remaining charge amount of the battery 20 will increase as the vehicle 10 travels through the second section L2 and the fourth section L4, which are the high load sections HS changed to the charging HV driving mode (see the dotted line in FIG. 5(A)). As described above, in the second process, at least a part of the driving mode plan data created in the first process is changed.

[0040] In step S22, the hybrid ECU 22 does not need to change all of the normal HV driving modes assigned to the high load section HS located before the low load section LS to the charging HV driving mode. For example, in this embodiment, either one of the normal HV driving modes assigned to the second section L2 or the fourth section L4 may be changed to the charging HV driving mode.

[0041] In step S24, the hybrid ECU 22 selectively executes one of a plurality of driving modes based on the driving mode plan data. The plurality of driving modes include an EV driving mode, a normal HV driving mode, and a charging HV driving mode. As described above, the driving mode plan data is created by the first process, and when both steps S18 and S20 are YES, at least a part of the driving mode plan data is changed by the second process. For the current position of the vehicle 10, the hybrid ECU 22 selects the EV driving mode if the EV driving mode is described in the driving mode plan data, selects the normal HV driving mode if the normal HV driving mode is described, and selects the charging HV driving mode if the charging HV driving mode is described. The hybrid ECU 22 can execute one of the EV driving mode, the normal HV driving mode, and the charging HV driving mode by controlling the engine 16 and the motor 18.

[0042] In step S26, the hybrid ECU 22 determines whether the vehicle 10 has reached the end point G of the predicted travel route PR. If the vehicle 10 has not reached the end point G of the predicted travel route PR (NO in step S26), the hybrid ECU 22 returns to the process of step S16 and executes the subsequent processes again. As a result, the hybrid ECU 22 repeatedly executes a plurality of processes (steps S16-S26) including processes for creating and changing the travel mode plan data at a predetermined interval until the vehicle 10 reaches the end point G of the predicted travel route PR. That is, while the vehicle 10 is traveling on the predicted travel route PR, the travel mode plan data is repeatedly updated at a predetermined interval. Although not particularly limited, the predetermined interval here may be, for example, one minute.

[0043] For example, assume that the vehicle 10 travels to the fourth section L4 and reaches the point P in FIG. 6. At this stage, as shown in FIGS. 6(A) and 6(B), the vehicle 10 travels in the second section L2 and the fourth section L4, which are the high load sections HS, in the charging HV travel mode, and the battery 20 is charged while traveling in each of the sections L2 and L4. Therefore, the actual remaining charge amount of the battery 20 at the point P is larger than the estimated value estimated at the time when the vehicle 10 is located at the start point S of the predicted travel route. Therefore, as shown in FIG. 6(B), when the hybrid ECU 22 executes the process of step S16 again, the normal HV travel mode assigned to the sixth section L6, which is the low load section LS, in the travel mode plan data of FIG. 5(B) can be changed to the EV travel mode. After that, the hybrid ECU 22 continues the driving assistance based on the travel mode plan data.

[0044] When the vehicle 10 reaches the end point G of the predicted travel route PR (YES in step S26), the hybrid ECU 22 ends the series of control operations shown in Fig. 3. Although not particularly limited, the hybrid ECU 22 may end the series of control operations when it determines that an assistance end condition is satisfied. The assistance end condition includes, for example, an instruction or operation by a user, or the vehicle 10 being stopped.

[0045] According to the above configuration, while the vehicle 10 is traveling on the predicted travel route PR, a process of creating travel mode plan data and a process of selecting a travel mode based on the travel mode plan data are repeatedly executed. In the process of creating the travel mode plan data, the hybrid ECU 22 assigns the EV travel mode to at least one section and the normal HV travel mode to the other sections until the sum of the required travel energies EE reaches the remaining charge amount of the battery 20 (see Figs. 4A and 4B). Therefore, for example, when the remaining charge amount of the battery 20 is relatively small, the normal HV travel mode may be assigned to the sixth section L6, which is the low load section LS. In this case, the hybrid ECU 22 refers to the other sections to which the normal HV travel mode is assigned, and changes the normal HV travel mode assigned to the second section L2 and the fourth section L4, which are located before the low load section LS (i.e., the sixth section L6) and are the high load section HS, to the charging HV travel mode (see Fig. 5B). Thereafter, when the vehicle 10 travels through the second section L2 and the fourth section L4, which are the high load sections HS where the charging HV driving mode has been changed, the remaining charge of the battery 20 increases (see FIG. 6(A)). As a result, when the process of creating the driving mode plan data is executed again, the normal HV driving mode assigned to the sixth section L6, which is the low load section LS, is changed to the EV driving mode (see FIG. 6(B)). As described above, even when the remaining charge of the battery 20 is relatively low, by increasing the remaining charge of the battery 20 in the high load section HS, it becomes possible to more reliably select the EV driving mode in the low load section LS. Therefore, high energy efficiency can be achieved in the vehicle 10.

[0046] As an example, the hybrid ECU 22 may be configured to execute steps S22A-S22D shown in Fig. 7 in step S22 of Fig. 3. The processing of steps S22A-S22D will be described below with reference to Fig. 7.

[0047] After completing the process of step S20 in FIG. 3, the hybrid ECU 22 prioritizes the high-load sections HS located before the low-load section LS determined to exist in step S18 and to which the normal HV driving mode is assigned in order of the driving load in step S22A in FIG. 7. Next, the hybrid ECU 22 changes the normal HV driving mode of the high-load section HS with the highest priority to the charging HV driving mode (step S22B). For example, in the driving mode plan data shown in FIG. 4(B), when the driving load of the fourth section L4 is higher than the driving load of the second section L2, the priority of the second section L2 is set to 1, and the priority of the fourth section L4 is set to 2 (step S22A). Therefore, first, for the second section L2 with the priority set to 1, the normal HV driving mode is changed to the charging HV driving mode (step S22B).

[0048] Then, the hybrid ECU 22 calculates an estimate of the charge increase amount to which the battery 20 is charged by the charging HV traveling mode changed in step S22 (step S22C). Here, the estimate of the charge increase amount to which the battery 20 is charged is a value calculated by multiplying the charge increase amount per unit distance to which the battery 20 is charged when the vehicle 10 travels in the charging HV traveling mode by the distance of the section changed to the charging HV traveling mode in step S22. For example, when the second section L2 is changed to the charging HV traveling mode in step S22B, the estimate of the charge increase amount is calculated by multiplying the charge increase amount per unit distance by the distance of the second section L2. Note that the charge increase amount per unit distance of the battery 20 may be a value calculated based on an experiment or the like, or may be a value empirically calculated from the traveling history of the vehicle 10 or the like.

[0049] In step S22D, the hybrid ECU 22 determines whether the estimated value (or the sum of the estimated values) of the charge increase amount calculated in step S22C exceeds the required traveling energy EE of the low-load section LS determined to exist in step S18. If the result is NO in step S22D, the hybrid ECU 22 returns to the process of step S22B and changes the normal HV traveling mode assigned to the low-load section LS with the priority level set to 2 to the charging HV traveling mode. Therefore, the hybrid ECU 22 repeats the processes from step S22B to step S22D until the result is YES in step S22D. In other words, until the result is YES in step S22D, the normal HV traveling mode assigned to the low-load section LS is changed to the charging HV traveling mode in order of the highest priority (i.e., in order of highest traveling load), and the low-load section LS in which the charging HV traveling mode is changed is added. If the result in step S22D is YES, the hybrid ECU 22 proceeds to the process of step S24 in FIG. 3, and selectively executes one of the plurality of driving modes based on the driving mode plan data.

[0050] For example, when the driving mode plan data shown in FIG. 4B is created, the low load section LS with the first priority is the second section L2, and the estimated value of the charge increase amount of the battery 20 in the second section L2 does not exceed the required traveling energy EE of the sixth section L6, the hybrid ECU 22 returns to the process of step S22B with NO in step S22D. Then, the hybrid ECU 22 changes the normal HV driving mode assigned to the fourth section L4, which is the low load section LS with the second priority, to the charging HV driving mode (step S22B), and calculates the estimated value of the charge increase amount of the battery 20 for the fourth section L4 (step S22C). When the sum of the estimated value of the charge increase amount of the battery 20 in the second section L2 and the estimated value of the charge increase amount of the battery 20 in the fourth section L4 exceeds the required traveling energy EE of the sixth section L6 (YES in step S22D), the process proceeds to the process of step S24 in FIG. 3. In addition, if the estimated charge increase amount of the battery 20 in the second section L2 exceeds the required driving energy EE of the sixth section L6 (YES in step S22D), only the normal HV driving mode assigned to the second section L2 is changed to the charging HV driving mode.

[0051] With this configuration, the charging HV driving mode can be assigned preferentially to sections with high driving loads where the output of the engine 16 is relatively high, thereby efficiently charging the battery 20. In addition, the section in which the driving mode is changed to the charging HV driving mode can be appropriately set according to the required driving energy EE in the low load section LS.

[0052] It is not necessary for the hybrid ECU 22 to execute all of the processes in steps S22A-S22D. As an example, the hybrid ECU 22 may omit the process in step S22A. In this case, the hybrid ECU 22 may change the normal HV driving mode assigned to each section to the charging HV driving mode in any order of priority without considering the driving load in step S22B. Alternatively, the hybrid ECU 22 may omit the processes in steps S22C-S22D. In this case, although not limited thereto, the hybrid ECU 22 may change the normal HV driving mode assigned to a section having a predetermined priority or higher to the charging HV driving mode without considering the amount of charge increase of the battery 20.

[0053] As an example, the hybrid ECU 22 may be configured to execute steps S16A-S16E shown in Fig. 8 in the first process of step S16 in Fig. 3. The process of steps S16A-S16E will be described below with reference to Fig. 8.

[0054] When the hybrid ECU 22 determines that the predicted travel route PR passes through a predetermined EV priority zone (YES in step S16A), the hybrid ECU 22 assigns the EV driving mode by giving priority to the EV priority sections included in the EV priority zone (step S16B). As a result, the EV driving mode is assigned to the EV priority sections included in the EV priority zone. Here, the EV priority zone includes, for example, a downhill section. In addition to this, or instead, the EV priority zone may include an urban area where the travel of the vehicle 10 with the engine 16 in operation is restricted, such that the EV driving mode is mandatory or strongly recommended. Information defining such an EV priority zone is included in the map information, and is transmitted from the navigation ECU 24 to the hybrid ECU 22.

[0055] In step S16C, the hybrid ECU 22 prioritizes the sections excluding the EV priority section in ascending order of traveling load. Next, the hybrid ECU 22 assigns the EV driving mode to the section with the priority level of 1, i.e., the low-load section LS with the lowest traveling load (step S16D). Then, the hybrid ECU 22 determines whether the required traveling energy EE of the low-load section LS to which the EV driving mode was assigned in step S16D has reached the remaining charge amount of the battery 20 (step S16E).

[0056] If the result in step S16E is NO, the hybrid ECU 22 returns to the process of step S16D and changes the normal HV driving mode assigned to the low load section LS, which has a second priority, to the charging HV driving mode. Therefore, the hybrid ECU 22 repeats the processes of steps S16D and S16E until the result in step S16E is YES. In other words, the EV driving mode is assigned to each section in descending order of priority (i.e., in descending order of driving load) until the result in step S16E is YES. If the result in step S16E is YES, the hybrid ECU 22 proceeds to the process of step S18 in FIG. 3.

[0057] With this configuration, the EV driving mode can be reliably assigned to the EV priority section included in the EV priority area. In this case, if the battery 20 has a remaining charge capacity, the EV driving mode can be preferentially assigned to the low load section LS where the driving load is relatively low. As a result, the energy efficiency of the vehicle 10 can be further improved.

[0058] It is not necessary for the hybrid ECU 22 to execute all of the processes in steps S16A-S16E. As an example, the hybrid ECU 22 may omit the processes in steps S16A-S16B. In this case, the hybrid ECU 22 may prioritize all sections constituting the predicted travel route PR in step S16C, starting with sections with low travel loads. Alternatively, the hybrid ECU 22 may omit the process in step S16C. In this case, the hybrid ECU 22 may assign the EV travel mode to each section in any order of priority in step S16E, without considering the priority order of travel loads. However, it is preferable to assign the EV travel mode to the section that is the low load section LS.

[0059] Although several specific examples have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical usefulness alone or in combination. [Explanation of symbols]

[0060] 10: Vehicle 12: Body 12c: Cabin 14f: Front wheel 14r: Rear wheel 16: Engine 18: Motor 20: Battery 22: Hybrid ECU 24: Navigation ECU 26: Display EE: Required driving energy EP: Required driving power G: End point HS: High load section LS: Low load section P: Point PR: Predicted driving route

Claims

1. A hybrid vehicle, A motor and an engine for driving; a battery that supplies driving power to the motor and is charged by power generated by the motor; A control device configured to be able to control the motor and the engine and capable of selectively executing a plurality of driving modes; Equipped with the plurality of driving modes include at least an EV driving mode in which the vehicle runs on the motor while the engine is stopped, a normal HV driving mode in which the vehicle runs on the engine and / or the motor while the engine is operating, and a charging HV driving mode in which the vehicle runs on the engine and / or the motor while the engine is operating and the amount of charge to the battery is increased compared to the normal HV driving mode; The control device, while the hybrid vehicle is traveling along a predicted traveling route, A process of creating driving mode plan data describing any one of the plurality of driving modes for each of a plurality of sections constituting the predicted driving route; A process of selectively executing the plurality of driving modes based on the driving mode plan data is repeatedly performed; The process of creating the driving mode plan data includes: A process of acquiring the predicted driving route; A process of identifying a required travel energy required to travel each of the plurality of sections of the predicted travel route; a first process of allocating the EV driving mode to at least one of the plurality of sections and allocating the normal HV driving mode to the remaining sections until the sum of the required driving energies reaches a remaining charge amount of the battery; a second process of changing at least one of the normal HV driving modes assigned to a high load section that is located before the low load section and satisfies a predetermined condition to the charging HV driving mode when a low load section that satisfies a predetermined condition is present among the sections to which the normal HV driving modes are assigned; Including, Hybrid car.

2. 2. The hybrid vehicle according to claim 1, wherein in the second process, sections changed to the charging HV driving mode are added until an estimated value of the increased charge amount charged to the battery by changing to the charging HV driving mode exceeds the required driving energy of the low load section to which the normal HV driving mode is assigned.

3. 3. The hybrid vehicle according to claim 1, wherein in the second processing, when there are multiple high load sections to which the normal HV driving mode is assigned before the low load section to which the normal HV driving mode is assigned, the driving mode is changed to the charging HV driving mode in descending order of driving load.

4. 4. The hybrid vehicle according to claim 1, wherein the predetermined conditions defining the low load section include at least one of a narrow road, a congested road, a crowded road, and a required driving power being lower than a predetermined lower limit value.

5. 5. The hybrid vehicle according to claim 1, wherein the predetermined conditions defining the high load section include at least one of the following: the section is an expressway, the section is a non-congested road, and the required driving power exceeds a predetermined upper limit value.

6. 6. The hybrid vehicle according to claim 1, wherein in the charging HV driving mode, a target lower limit value of the remaining charge amount of the battery is set to a value greater than the remaining charge amount at a start point of the charging HV driving mode.

7. The hybrid vehicle according to claim 1 , wherein in the charging HV running mode, the upper limit value of the remaining charge amount of the battery is invalidated.

8. 8. The hybrid vehicle according to claim 1, wherein, in the first process, when the predicted driving route passes through a predetermined EV priority area, the EV driving mode is assigned preferentially to an EV priority section included in the EV priority area.

9. The hybrid vehicle according to claim 1 , wherein in the first process, the EV driving mode is assigned preferentially to sections with low driving loads.

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