Hybrid vehicle

Abstract

To eliminate a sense of discomfort given to a driver by performing motor travel on an expressway and performing hybrid travel on an ordinary road near a destination.SOLUTION: A control device of a hybrid vehicle executes travel support control such that the vehicle travels on the basis of a travel support plan in which, by using information on each travel section of a planned or estimated travel route based on map information and an own vehicle position, a CD mode or a CS mode is assigned to each travel section. In addition, the control device executes control such that the vehicle travels in the CS mode while traveling on an expressway when a distance to a destination is a prescribed distance or longer and is longer than an electrically-driven travel range obtained on the basis of a power storage ratio of a power storage device.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, for this type of hybrid vehicle, when the planned driving range is longer than the possible driving range calculated from the charge state of the on-board power storage device, a system has been proposed in which the engine is operated and the power storage device is charged by a generator until the amount of stored electricity in the power storage device reaches an amount corresponding to the planned driving range (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-251648 Summary of the Invention [Problem to be solved by the invention]

[0004] When the amount of energy required for traveling the planned route can be covered by the amount of electricity stored in the electricity storage device, the vehicle can travel on electric power, but when the load forecast for the planned route is estimated to be lower than the actual load, the amount of electricity stored in the electricity storage device will be insufficient, and it will be necessary to operate the engine before reaching the destination.If the planned route includes a highway, the vehicle will travel on electric power on the highway and on hybrid power on ordinary roads near the destination, which may cause discomfort to the driver.

[0005] The hybrid vehicle disclosed herein is primarily intended to eliminate the sense of discomfort felt by the driver when the vehicle is driven by motor on expressways and by hybrid on ordinary roads near the destination. [Means for solving the problem]

[0006] The hybrid vehicle of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The hybrid vehicle disclosed herein is a hybrid vehicle equipped with an engine capable of outputting power for driving, a motor capable of outputting power for driving, a storage device capable of exchanging power with the motor, and a control device that executes driving assistance control to drive the engine and the motor by switching between a CD mode that prioritizes electric driving so as to reduce the storage ratio of the storage device and a CS mode that combines electric driving and hybrid driving so as to maintain the storage ratio of the storage device, and that executes driving assistance control to drive based on a driving assistance plan that assigns the CD mode or the CS mode to each driving section using information about each driving section of a planned or estimated driving route based on map information and the vehicle's position, and is characterized in that the control device controls the vehicle to drive in the CS mode when driving on a highway where the distance to the destination is equal to or greater than a predetermined distance and is longer than the electric driving range obtained based on the storage ratio of the storage device.

[0008] In the hybrid vehicle disclosed herein, when the distance to the destination is equal to or greater than a predetermined distance and is longer than the electric driving range obtained based on the power storage rate of the power storage device, the hybrid vehicle is controlled to run in CS mode when running on a highway. By running in CS mode (hybrid driving mode) while running on a highway, it is possible to eliminate the discomfort felt by the driver when running in CS mode (hybrid driving mode) on ordinary roads near the destination. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an example of a hybrid vehicle 20 according to an embodiment. [Figure 2] 4 is a flowchart illustrating an example of driving support control. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, a mode (embodiment) for carrying out the present disclosure will be described. FIG. 1 is a block diagram illustrating an example of a hybrid vehicle 20 according to an embodiment of the present disclosure, focusing on a hybrid electronic control unit (hereinafter referred to as a hybrid ECU) 50. As illustrated, the hybrid vehicle 20 of the embodiment includes an engine EG and a motor MG as power sources. The hybrid vehicle 20 of the embodiment has two driving modes: a motor driving mode in which the vehicle runs on power from the motor MG with the engine EG stopped, and a normal driving mode in which the vehicle runs on power from the engine EG and the motor MG by operating the engine EG as needed. The normal driving mode includes a CD mode (Charge Depleting mode) that prioritizes electric driving so as to reduce the state of charge (SOC) of the battery 44, and a CS mode (Charge Sustaining mode) that combines electric driving and hybrid driving so as to maintain the state of charge (SOC) of the battery 44 at a target rate.

[0011] In addition to the power source, the hybrid vehicle 20 of this embodiment is equipped with an ignition switch 21, a GPS (Global Positioning System, Global Positioning Satellite) 22, an on-board camera 24, a millimeter-wave radar 26, an acceleration sensor 28, a vehicle speed sensor 30, an accelerator sensor 32, a brake sensor 34, a mode selector switch 36, an air conditioner electronic control unit (hereinafter referred to as the air conditioner ECU) 38, an air conditioner compressor 40, a battery actuator 42, a battery 44, a charger 46, a hybrid ECU 50, an accelerator actuator 60, a brake actuator 62, a brake device 64, a display device 66, a driving status indicator 67, a DCM (Data Communication Module) 70, a navigation system 80, and the like.

[0012] The battery actuator 42 detects the state of the battery 44, such as the terminal voltage, charge / discharge current, and battery temperature, and manages the battery 44 based on these. The battery actuator 42 calculates the power storage ratio SOC as the ratio of the remaining power storage capacity to the total power storage capacity based on the charge / discharge current, and calculates the maximum allowable output power (output limit Wout) that may be output from the battery 44 and the maximum allowable input power (input limit Win) that may be input to the battery 44 based on the power storage ratio SOC, battery temperature, etc. The battery 44 may be, for example, a lithium-ion battery. The charger 46 charges the battery 44 using power from an external power source 110, such as a commercial power source.

[0013] The engine EG is configured as, for example, an internal combustion engine. The motor MG is configured as, for example, an electric motor that also functions as a generator, such as a synchronous motor. The motor MG is connected to a battery 44 via an inverter (not shown), and can output driving force using power supplied from the battery 44 and charge the battery 44 with the generated power.

[0014] The hybrid ECU 50 is configured as a microcomputer centered around a CPU (not shown), and sets the driving mode and also sets the target operating point (target rotation speed and target torque) of the engine EG and the torque command of the motor MG based on the set driving mode, the accelerator opening from the accelerator sensor 32, the brake position from the brake sensor 34, and the output and input limits from the battery actuator 42.

[0015] When driving by motor, hybrid ECU 50 sets a torque command for motor MG based on the accelerator opening from accelerator sensor 32 and the vehicle speed from vehicle speed sensor 30, and sends the set torque command to accelerator actuator 60. When driving by hybrid, hybrid ECU 50 sets a target operating point for engine EG and a torque command for motor MG so as to output a required driving force and a required power to the vehicle, and sends the target operating point and torque command to accelerator actuator 60. When the brake pedal is depressed, hybrid ECU 50 sets a required braking force based on the brake position from brake sensor 34 and the vehicle speed from vehicle speed sensor 30, and sets a regenerative torque command for regenerative control of motor MG and a target braking force by the brake device based on the required braking force and the vehicle speed, and sends the torque command to accelerator actuator 60 and the target braking force to brake actuator 62.

[0016] The accelerator actuator 60 controls the intake air amount, fuel injection, ignition, intake valve opening / closing timing, etc. so that the engine EG is operated at a target operating point (target rotation speed and target torque). The accelerator actuator 60 controls the switching of switching elements of an inverter that drives the motor MG so that a torque corresponding to a torque command is output from the motor MG. The brake actuator 62 controls the brake device 64 so that a target braking force is applied to the vehicle by the brake device 64.

[0017] The DCM (Data Communication Module) 70 communicates with the traffic information management center 100 at predetermined intervals (for example, every 30 seconds, every minute, or every two minutes), transmits information about the vehicle to the traffic information management center 100, and receives road traffic information from the traffic information management center 100. Examples of the vehicle information include the vehicle's position, vehicle speed, driving power, and driving mode. Examples of the road traffic information include information about current and future congestion, information about the current average vehicle speed and predicted future average vehicle speed in sections along the travel route, information about traffic regulations, information about weather, information about road surface conditions, and information about maps.

[0018] The navigation system 80 includes a display unit 82 and a map information database 84. The display unit 82 is a functional block having a function of displaying the route to the destination, the vehicle's position, and the like on the display device 66 based on map information. When the destination and waypoints are set, the navigation system 80 sets a route based on the information about the destination and waypoints, information about the current location (current vehicle position) acquired by the GPS 22, and information stored in the map information database 84. When providing route guidance, the navigation system 80 generates, as look-ahead information, information about each traveling section within the traveling route and information about the traveling load, which are included in the road traffic information acquired from the traffic information management center 100, as well as load information required to travel each traveling section based on the vehicle's speed, the vehicle's traveling power, the vehicle's traveling mode, and the like, and transmits the information to the hybrid ECU 50. The look-ahead information includes information about the vehicle, such as the vehicle's position, vehicle speed, driving power, and driving mode, as well as information about current and future traffic congestion, information about the current average vehicle speed and predicted future average vehicle speed for sections of the driving route, information about traffic regulations, information about weather, information about road surface conditions, and information about maps. The map information also includes areas where motor driving is required (motor driving areas) designated by municipalities and the like. The navigation system 80 can also set a motor driving area by specifying an area, such as an area near the user's home, through user operation.

[0019] Next, the operation of the hybrid vehicle 20 configured as described above, and the operation when the hybrid vehicle 20 travels in the motor driving range in accordance with the driving support plan, will be described. Fig. 2 is a flowchart showing an example of driving support control executed by the hybrid ECU 50. This flowchart is executed after the ignition switch 21 is turned on.

[0020] When driving assist control is executed, the hybrid ECU 50 first determines whether the look-ahead information transmitted from the navigation system 80 has been updated (step S100). If it determines that the look-ahead information has been updated, the hybrid ECU 50 acquires information on a planned or estimated driving route within a predetermined range from the current location (step S110). The predetermined range can be 10 km, 20 km, or up to the destination. The planned driving route is a driving route planned by the navigation system 80 as route guidance from the current location to the destination when the destination is set, and the estimated driving route is a driving route estimated to be traveled from the current location.

[0021] Next, a driving assistance plan is created (step S120). The driving assistance plan can be created by, for example, assigning the motor driving mode to the motor driving sections of each driving section of the driving route, and for the other driving sections, calculating the total energy Esum as the sum of the energy consumption E(n) of each driving section of the driving route from the current location to the control end section (destination), subtracting the energy consumption E(n) of the driving section (motor driving section) assigned the motor driving mode from the total energy Esum to calculate the total remaining energy Eev, and assigning the CD mode to all driving sections when the total remaining energy Eev is equal to or less than the remaining charge of the battery 44, and when the total remaining energy Eev is greater than the remaining charge of the battery 44, sorting the other driving sections in order of decreasing driving load, and assigning them to the CD mode in order of decreasing driving load until the sum of the energy consumption En of the assigned driving sections exceeds the remaining charge of the battery 44, and assigning the remaining driving sections to the CS mode. Then, the driving mode is controlled in accordance with the driving assistance plan (step S130).

[0022] When it is determined in step S100 that the look-ahead information has not been updated, or after it is determined in step S100 that the look-ahead information has been updated and a driving support plan is created and driving mode control in accordance with the driving support plan is started, the distance Dtg to the destination is calculated (step S140), and it is determined whether the distance Dtg to the destination is equal to or greater than a predetermined distance Dref1 (step S150). The predetermined distance Dref1 can be, for example, 20 km, 30 km, 50 km, 100 km, or 200 km. When it is determined that the distance Dtg to the destination is equal to or greater than the predetermined distance Dref1, the motor driving range Dev is estimated based on the power storage rate SOC of the battery 44 (step S160), and it is determined whether the motor driving range Dev is less than the distance Dtg to the destination (step S170). When it is determined that the motor traveling range Dev is less than the distance Dtg to the destination, it is determined whether the vehicle is traveling on a highway (step S180), and when it is determined that the vehicle is traveling on a highway, the vehicle switches to CS mode (step S190). As a result, when the vehicle is traveling on a highway and the distance Dtg to the destination is equal to or greater than the predetermined distance Dref1 and the motor traveling range Dev is less than the distance Dtg to the destination, the vehicle operates in hybrid mode to maintain the charge storage rate SOC of the battery 44. Note that when it is determined in step S150 that the distance Dtg to the destination is less than the predetermined distance Dref1, when it is determined in step S170 that the motor traveling range Dev is equal to or greater than the distance Dtg to the destination, or when it is determined in step S180 that the vehicle is not traveling on a highway, the vehicle does not switch to CS mode.

[0023] Then, it is determined whether or not the control termination condition is satisfied (step S200). If it is determined that the control termination condition is not satisfied, the process returns to step S100 of the process of determining whether or not the look-ahead information has been updated, and if it is determined that the control termination condition is satisfied, the driving support control is terminated.

[0024] In the hybrid vehicle 20 of the embodiment described above, when the distance Dtg to the destination is equal to or greater than the predetermined distance Dref1 and the motor-driving range Dev is less than the distance Dtg to the destination and the vehicle is traveling on a highway, the hybrid vehicle runs in hybrid mode to maintain the charge storage ratio SOC of the battery 44. This makes it possible to prevent the driver from feeling uncomfortable when the vehicle runs in motor mode on the highway and in hybrid mode on ordinary roads near the destination.

[0025] In the hybrid vehicle 20 of the embodiment, when the distance Dtg to the destination is equal to or greater than the predetermined distance Dref1 and the motor driving range Dev is less than the distance Dtg to the destination and the vehicle is traveling on a highway, the vehicle runs in the CS mode to maintain the power storage ratio SOC of the battery 44. However, the vehicle may also run in the CS mode when traveling on a highway even when the motor driving range Dev is equal to or greater than the distance Dtg to the destination.

[0026] The present disclosure has been described above using embodiments, but the present disclosure is not limited to these embodiments and can, of course, be embodied in various forms within the scope of the gist of the present disclosure. [Industrial Applicability]

[0027] The present disclosure is applicable to the hybrid vehicle manufacturing industry and the like. [Explanation of symbols]

[0028] 20 Hybrid vehicles, 44 Batteries, 46 Chargers, 50 Hybrid electronic control units (hybrid ECUs), EG engines, MG motors.

Claims

[Claim 1] a control device that executes driving assistance control for driving the vehicle based on a driving assistance plan in which the CD mode or the CS mode is assigned to each driving section of a planned or estimated driving route based on map information and a vehicle position, when controlling the engine and the motor by switching between a CD mode that prioritizes electric driving so as to reduce a power storage ratio of the power storage device and a CS mode that uses both electric driving and hybrid driving so as to maintain a power storage ratio of the power storage device, The control device controls the hybrid vehicle to run in the CS mode when the vehicle is running on a highway and the distance to the destination is equal to or greater than a predetermined distance and is longer than the electric driving range obtained based on the storage rate of the storage device.

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