Hybrid vehicle control device

Abstract

To provide a hybrid vehicle controller capable of improving NV performance in automatic drive.SOLUTION: During unmanned automatic drive, NV suppression control for setting a request charging power at a larger value than during the execution of manned automatic drive. This causes a larger charging power to a battery during the execution of unmanned automatic drive making a NV deterioration hard to be problematic, so that a charging residual quantity of the battery at the start of manned automatic drive transferred from unmanned automatic drive is increased as compared with continuation of manned automatic drive. Accordingly, after the start of manned automatic drive transferred from unmanned automatic drive, the time when an engine remains suspended is increased, or the rotational speed of the engine is reduced during a large residual quantity of the battery. Therefore, NV performance can be improved in automatic drive.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for a hybrid vehicle equipped with an engine and an electric motor. [Background technology]

[0002] Control devices for hybrid vehicles that include an engine, an electric motor, and a battery that supplies and receives power to the electric motor are well known. For example, Patent Document 1 discloses a driving control device for a hybrid vehicle. Patent Document 1 discloses that the driving modes include an HEV driving mode, which allows the vehicle to run using both the engine and the electric motor, and a BEV driving mode, which allows the vehicle to run using only the electric motor. Patent Document 1 also discloses that the BEV driving mode is adopted when the remaining charge of the battery is sufficiently high, and the HEV driving mode is adopted when the remaining charge is below a predetermined threshold. Patent Document 1 also discloses that in the HEV driving mode, the engine is operated with its operating point positioned on a fuel efficiency optimization line. Patent Document 1 also discloses that the driving control includes a manual driving control that drives the vehicle based on the driver's driving operation, and an automatic driving control that drives the vehicle by automatically steering, accelerating, and decelerating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-43544 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in Patent Document 1, in a hybrid vehicle, when the engine operating point is determined to optimize energy efficiency, the engine speed may become high. Meanwhile, during autonomous driving, since no driver operation is required, switching between starting and stopping the engine or fluctuations in the engine speed may worsen NV compared to manual driving. There is room for improvement in NV performance, i.e., performance in suppressing NV deterioration during autonomous driving. "Autonomous driving" refers to driving under automatic driving control. "Manual driving" refers to driving under manual driving control. "NV" is a general term for noise and vibration generated by a vehicle, and refers to at least one of noise and vibration in the vehicle. Autonomous driving includes manned autonomous driving, which involves at least one person, such as a driver, owner, user, passenger, crew member, or passenger, and unmanned autonomous driving, which involves no person, such as a driver, passenger, crew member, or passenger, on board. "Manned autonomous driving" refers to manned driving under automatic driving control. "Unmanned autonomous driving" refers to unmanned driving under automatic driving control.

[0005] The present invention has been made against the background of the above circumstances, and its object is to provide a control device for a hybrid vehicle that can improve NV performance during autonomous driving. [Means for solving the problem]

[0006] The gist of a first aspect of the present invention is a control device for a hybrid vehicle including (a) an engine, an electric motor, and a battery that supplies and receives electric power to the electric motor, the control device including: (b) a driving control unit that performs manual driving control for driving the hybrid vehicle based on driving operations by a driver, and automatic driving control for driving the hybrid vehicle by automatically steering and accelerating and decelerating; and (c) a charging control unit that performs NV suppression control for setting a required charging power for charging the battery by generating power from the electric motor using power from the engine to a higher value during unmanned driving under the automatic driving control than during manned driving under the automatic driving control.(d) when the driving control unit determines that the vehicle will transition from unmanned driving to manned driving during the automatic driving control, the charging control unit performs the NV suppression control during the unmanned driving until the manned driving starts, and (e) during the unmanned driving, the charging control unit calculates the required charging power based on the travel distance from the current point to the point at which the vehicle will transition to manned driving and the current remaining charge of the battery. The reason is that. [Effects of the Invention]

[0007] According to the first aspect of the present invention, NV suppression control is performed during unmanned automatic driving, in which the required charging power is set to a higher value than during manned automatic driving. This increases the charging power to the battery during unmanned automatic driving, when NV deterioration is less likely to be a problem, and increases the remaining battery charge at the start of manned automatic driving following unmanned automatic driving compared to during manned automatic driving. Therefore, during the period when the remaining battery charge is high after the start of manned automatic driving following unmanned automatic driving, the time the engine is stopped is increased or the engine speed is reduced. This improves NV performance during automatic driving. In addition, when a decision is made to transition from unmanned autonomous driving to manned autonomous driving, NV suppression control is performed during unmanned autonomous driving until manned autonomous driving begins. This allows the remaining battery charge at the start of manned autonomous driving to be appropriately increased compared to when manned autonomous driving is ongoing. Furthermore, while unmanned automatic driving is being performed, the required charging power is calculated based on the travel distance from the current location to the point where manned automatic driving will be performed and the current remaining charge of the battery. As a result, the required charging power is appropriately set to a larger value during unmanned automatic driving than during manned automatic driving. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and control systems for various controls in the vehicle. [Figure 2] 1 is a flowchart illustrating a main part of the control operation of the electronic control device, and is a flowchart illustrating the control operation for improving NV performance during autonomous driving. [Figure 3] 3 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 2 is executed. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0010] FIG. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrates essential parts of a control system for various controls in the vehicle 10. In FIG. 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and electric motors, a first electric motor MG1 and a second electric motor MG2. The engine 12 and the second electric motor MG2 function as a power source SP for traveling. The vehicle 10 also includes drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14.

[0011] The engine 12 is a known internal combustion engine. An engine control device 50 provided in the vehicle 10 is controlled by an electronic control device 90 (described later), whereby the engine torque Te of the engine 12 is controlled.

[0012] The first electric motor MG1 and the second electric motor MG2 are rotating electric machines, so-called motor generators. The first electric motor MG1 and the second electric motor MG2 are each connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The battery 54 is an electricity storage device that supplies and receives electric power to and from each of the first electric motor MG1 and the second electric motor MG2. The inverter 52 is controlled by an electronic control device 90 (described later), thereby controlling the MG1 torque Tm1 of the first electric motor MG1 and the MG2 torque Tm2 of the second electric motor MG2. The first electric motor MG1 and the second electric motor MG2 are provided in a case 18 serving as a non-rotating member attached to the vehicle body.

[0013] The power transmission device 16 includes, within a case 18, a damper 20, an input shaft 22, a transmission unit 24, a compound gear 26, a driven gear 28, a driven shaft 30, a final gear 32, a differential gear 34, a reduction gear 36, and the like. The power transmission device 16 also includes, within the case 18, a rotor shaft RSmg1 integrally connected to the rotor MG1r of the first electric motor MG1, and a rotor shaft RSmg2 integrally connected to the rotor MG2r of the second electric motor MG2. The power transmission device 16 also includes, within the case 18, a pair of drive shafts 38 connected to the differential gear 34, and the like.

[0014] A drive gear 26a is formed on a portion of the outer circumferential surface of the compound gear 26. The driven gear 28 is in mesh with the drive gear 26a. The driven shaft 30 fixes the driven gear 28 and a final gear 32 so that they cannot rotate relative to each other. The final gear 32 is in mesh with a differential ring gear 34a of the differential gear 34. The reduction gear 36 is connected to a rotor shaft RSmg2, and is connected to a second electric motor MG2 so as to be able to transmit power.

[0015] The transmission unit 24 includes a first electric motor MG1, a rotor shaft RSmg1, and a planetary gear set 40. The planetary gear set 40 is a known single-pinion planetary gear set including a sun gear S, a carrier CA, a ring gear R, and a pinion P. The planetary gear set 40 functions as a differential mechanism that generates a differential action. The planetary gear set 40 is a power split mechanism that mechanically splits the power of the engine 12 input to the carrier CA between the first electric motor MG1 and the drive gear 26a. The transmission unit 24 is a known electric continuously variable transmission in which the differential state of the planetary gear set 40 is controlled by controlling the operating state of the first electric motor MG1.

[0016] The vehicle 10 is equipped with an electronic control device 90 as a controller including control devices of the vehicle 10 related to the control of the engine 12, etc. The electronic control device 90 is configured to include a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc. The electronic control device 90 performs various controls of the vehicle 10 by the CPU performing signal processing in accordance with a program stored in advance in the ROM while utilizing the temporary storage function of the RAM.

[0017] The electronic control device 90 receives various signals (for example, engine rotation speed sensor 60, output rotation speed sensor 62, MG1 rotation speed sensor 64, MG2 rotation speed sensor 66, accelerator opening sensor 68, throttle valve opening sensor 70, brake pedal sensor 72, G sensor 74, yaw rate sensor 76, steering sensor 78, vehicle surroundings information sensor 80, vehicle position sensor 82, battery sensor 84, navigation system 86, automatic driving selection switch 88, etc.) based on detected values ​​from various sensors provided in the vehicle 10. The following signals are supplied to the control unit 10: MG rotation speed Ne, output rotation speed No, MG1 rotation speed Nm1, MG2 rotation speed Nm2, accelerator opening θacc, throttle valve opening θth, brake-on signal Bon, brake operation amount Bra, longitudinal acceleration Gx, lateral acceleration Gy, yaw rate Ryaw, steering angle θsw, steering direction Dsw, steering-on signal SWon, vehicle surrounding information Iard, position information Ivp, battery temperature THbat, battery charge / discharge current Ibat, battery voltage Vbat, navigation information Inavi, autonomous driving setting signal Sad, etc.

[0018] The engine rotation speed Ne is the rotation speed of the engine 12. The output rotation speed No is the rotation speed of the drive gear 26a and is a signal corresponding to the vehicle speed V. The MG1 rotation speed Nm1 is the rotation speed of the first electric motor MG1. The MG2 rotation speed Nm2 is the rotation speed of the second electric motor MG2. The accelerator opening θacc is a signal indicating the magnitude of the driver's acceleration operation, and is the amount of accelerator operation by the driver. The throttle valve opening θth is the opening of the electronic throttle valve. The brake-on signal Bon is a signal indicating the state in which the brake pedal for activating the wheel brakes is being operated by the driver. The brake operation amount Bra is a signal indicating the magnitude of the brake operation by the driver. The steering angle θsw is the steering angle of the steering wheel. The steering direction Dsw is the steering direction of the steering wheel. The steering-on signal SWon is a signal indicating the state in which the steering wheel is being gripped by the driver. The automatic driving setting signal Sad is a signal that indicates the setting made by the driver in the automatic driving control CTad.

[0019] The vehicle surroundings information sensor 80 includes at least one of, for example, a lidar, a radar, an on-board camera, etc. The vehicle surroundings information sensor 80 detects objects in front of, on the sides of, and behind the vehicle 10, and outputs object information related to the detected objects as vehicle surroundings information Iard.

[0020] The vehicle position sensor 82 includes a GPS antenna, etc. The position information Ivp includes host vehicle position information, which is information indicating the current position of the vehicle 10 on the earth's surface or a map based on GPS signals (orbital signals) transmitted by GPS (Global Positioning System) satellites, etc.

[0021] The navigation system 86 is a known navigation system. The navigation information Inavi includes map information such as road information and facility information based on map data stored in advance in the navigation system 86, for example.

[0022] The automatic driving selection switch 88 is a switch that is operated by the driver when the automatic driving control CTad is to be executed.

[0023] The electronic control device 90 outputs various command signals (e.g., an engine control command signal Se for controlling the engine 12, a motor control command signal Smg for controlling each of the first electric motor MG1 and the second electric motor MG2, a brake control command signal Sbra for controlling the wheel brakes, a steering control command signal Sste for controlling the steering of the front wheels, e.g., the drive wheels 14, etc.) to each device provided in the vehicle 10 (e.g., the engine control device 50, the inverter 52, the wheel brake device 56, the steering device 58, etc.).

[0024] The wheel brake device 56 includes a brake master cylinder and a cylinder actuator (not shown) that generate brake hydraulic pressure. Each of the wheels, including the drive wheels 14, is equipped with a wheel brake (not shown). The wheel brake device 56 is a brake device that applies braking torque to the wheels by the wheel brakes using the electronic control device 90. Under normal conditions, the wheel brake device 56 supplies master cylinder hydraulic pressure corresponding to the brake operation amount Bra to the wheel cylinder as brake hydraulic pressure. On the other hand, when, for example, the automatic driving control CTad is being executed, the wheel brake device 56 supplies brake hydraulic pressure corresponding to the required braking torque to the wheel cylinder.

[0025] The steering device 58 applies an assist torque to the steering system of the vehicle 10 according to, for example, the vehicle speed V, the steering angle θsw, the steering direction Dsw, the yaw rate Ryaw, etc. The steering device 58 applies a torque to the steering system of the vehicle 10 to control the steering of the front wheels, for example, during the automatic driving control CTad.

[0026] The electronic control unit 90 includes a hybrid control means, that is, a hybrid control unit 92, in order to realize various controls in the vehicle 10.

[0027] The hybrid control unit 92 includes an engine control function for controlling the operation of the engine 12 and an electric motor control function for controlling the operation of the first electric motor MG1 and the second electric motor MG2 via the inverter 52.

[0028] The hybrid control unit 92 calculates a drive demand amount, such as a required drive torque Trdem [Nm], by applying the accelerator opening θacc and the vehicle speed V to a predetermined drive demand amount map. The required drive torque Trdem is, in other words, a required drive power Prdem [W] at the vehicle speed V at that time. The hybrid control unit 92 outputs an engine control command signal Se and an electric motor control command signal Smg to realize the required drive power Prdem, taking into account, for example, transmission loss, auxiliary load, and the remaining charge SOC of the battery 54. The engine control command signal Se is a command value for engine power Pe that takes into account, for example, the engine optimum fuel efficiency point when the transmission unit 24 is operated as a continuously variable transmission. The engine power Pe is the power of the engine 12. The electric motor control command signal Smg is a command value for generated power Wm1 of the first electric motor MG1, which outputs an MG1 torque Tm1 as a reaction torque of the engine torque Te when the transmission unit 24 is operated as a continuously variable transmission. Furthermore, the motor control command signal Smg is a command value for the power consumption Wm2 of the second electric motor MG2 that outputs the MG2 torque Tm2. The engine optimum fuel economy point is predetermined as an engine operating point that provides the best overall fuel economy in the vehicle 10, that is, an optimum engine operating point, taking into consideration, for example, the fuel economy of the engine 12 alone and the transmission efficiency of the power transmission device 16. The operating point is a driving point expressed by the rotation speed and torque, and the engine operating point is a driving point of the engine 12 expressed by the engine rotation speed Ne and the engine torque Te.

[0029] The hybrid control unit 92 calculates the remaining charge SOC [%] based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat. The remaining charge SOC is the remaining charge of the battery 54 and is a value indicating the state of charge of the battery 54. The hybrid control unit 92 calculates the chargeable power Win [W] and dischargeable power Wout [W] of the battery 54 based on, for example, the battery temperature THbat and the remaining charge SOC.

[0030] The hybrid control unit 92 selectively establishes either a BEV driving mode or an HEV driving mode as the driving mode depending on the driving state. The BEV driving mode is a driving mode that enables BEV driving, in which the vehicle runs using the second electric motor MG2 as the power source SP while the engine 12 is stopped. The BEV driving mode is motor driving, in which the vehicle runs using only power from the second electric motor MG2. In the BEV driving mode, an MG2 torque Tm2 corresponding to the required driving torque Trdem is transmitted to the driving wheels 14. The HEV driving mode is a driving mode that enables HEV driving, in which the vehicle runs using at least the engine 12 as the power source SP. The HEV driving mode is hybrid driving, i.e., engine driving, in which the vehicle runs using at least power from the engine 12. In the HEV driving mode, the combined torque of the engine direct torque Td and the MG2 torque Tm2 corresponding to the required driving torque Trdem is transmitted to the driving wheels 14. The engine direct torque Td is a positive torque that appears in the ring gear R when the MG1 torque Tm1, which is a reaction torque of the negative torque of the first electric motor MG1, is input to the sun gear S in response to the engine torque Te, which is a positive torque, input to the carrier CA.

[0031] The hybrid control unit 92 establishes the BEV driving mode when the required driving power Prdem is in a BEV driving range that is smaller than a predetermined threshold. On the other hand, the hybrid control unit 92 establishes the HEV driving mode when the required driving power Prdem is in an HEV driving range that is equal to or greater than a predetermined threshold. In the HEV driving mode, the hybrid control unit 92 can perform control to set the engine operating point to the engine optimum fuel efficiency point. On the other hand, even when the required driving power Prdem is in the BEV driving range, the hybrid control unit 92 establishes the HEV driving mode when, for example, the battery 54 needs to be charged or the engine 12 needs to be warmed up.

[0032] The hybrid control unit 92 includes a charge control means, i.e., a charge control unit 94, for maintaining the state of charge (SOC) at an appropriate value. In the vehicle 10, the battery 54 is discharged by the power running of the first electric motor MG1 or the power running of the second electric motor MG2, and the battery 54 is charged by the power generation of the first electric motor MG1 or the power generation of the second electric motor MG2. The power generation of the first electric motor MG1 is generated using the power of the engine 12, and the power generation of the second electric motor MG2 is generated by the driven torque from the drive wheels 14.

[0033] The charge control unit 94 performs a remaining charge maintenance control CTsoc that maintains the remaining charge SOC within a predetermined remaining charge range RNGsoc by repeatedly discharging and charging the battery 54. The predetermined remaining charge range RNGsoc is, for example, a predetermined appropriate range of the remaining charge SOC for maintaining the performance of the battery 54.

[0034] The above-mentioned case where the battery 54 needs to be charged is, for example, when the state of charge SOC falls below the predetermined range of remaining charge RNGsoc, or when the state of charge SOC is within the predetermined range of remaining charge RNGsoc, but charging the battery 54 would improve the energy efficiency of the vehicle 10.

[0035] The charge control unit 94 calculates a required charge power Pchgdem, which is a required value for charge power Pchg [W] for charging the battery 54 using power generated by the first electric motor MG1 using the power of the engine 12, based on, for example, the difference between a target value for the state of charge SOC and the current state of charge SOCr. The current state of charge SOCr is the current state of charge SOC. When it becomes necessary to charge the battery 54, the charge control unit 94 outputs a command to the hybrid control unit 92 to achieve the required charge power Pchgdem. When it becomes necessary to charge the battery 54 during HEV driving, the engine power Pe is increased by the amount of charging. When it becomes necessary to charge the battery 54 during BEV driving, the engine 12 is started, and engine power Pe that achieves the required charge power Pchgdem is output.

[0036] The hybrid control unit 92 is equipped with a driving control means, i.e., a driving control unit 96, to perform both the manual driving control CTmd and the automatic driving control CTad. The driving demand amount based on the accelerator opening θacc and the like described above is the driving demand amount for the vehicle 10 by the driver during the manual driving control CTmd. During the automatic driving control CTad, the driving control unit 96 calculates the driving demand amount for the vehicle 10 required by the automatic driving control CTad.

[0037] The driving control unit 96 executes manual driving control CTmd and automatic driving control CTad as driving control of the vehicle 10. The manual driving control CTmd is driving control that drives the vehicle 10 based on the driving operation of the driver. The automatic driving control CTad is driving control that drives the vehicle 10 by automatically performing steering and acceleration / deceleration without relying on the driving operation of the driver. Note that acceleration / deceleration also includes braking.

[0038] When the automatic driving selection switch 88 is turned off, the driving control unit 96 establishes the manual driving mode and executes the manual driving control CTmd. The driving control unit 96 executes the manual driving control CTmd by outputting commands to the hybrid control unit 92 to control the engine 12, the first electric motor MG1, the second electric motor MG2, etc., in accordance with, for example, the driver's operation.

[0039] When the automatic driving selection switch 88 is turned on, the driving control unit 96 establishes the automatic driving mode and executes the automatic driving control CTad. The driving control unit 96 automatically sets a target driving state based on, for example, the destination, vehicle position information based on the position information Ivp, map information based on the navigation information Inavi, etc., and various information about the driving route based on the vehicle surroundings information Iard. The driving control unit 96 executes the automatic driving control CTad by outputting commands to the hybrid control unit 92, etc. to control the engine 12, the wheel braking device 56, the steering device 58, etc. so as to automatically perform acceleration / deceleration and steering based on the set target driving state.

[0040] Autonomous driving, which is driving under the Autonomous Driving Control CTad, can be manned or unmanned. Manned driving under the Autonomous Driving Control CTad is manned automatic driving, and unmanned driving under the Autonomous Driving Control CTad is unmanned automatic driving.

[0041] In manned automatic driving, since there are passengers, NV is more likely to deteriorate than in unmanned automatic driving, for example, when controlling the engine 12 to achieve an optimal engine operating point. Therefore, the electronic control device 90 increases the load on the engine 12 while unmanned automatic driving is being performed, thereby increasing the state of charge SOC at the start of manned automatic driving and extending the period during which the BEV driving mode can be established, thereby improving quietness.

[0042] The charging control unit 94 performs NV suppression control CTnv that sets the requested charging power Pchgdem to a larger value during unmanned automatic driving than during manned automatic driving.

[0043] When it has been decided to transition from unmanned automatic driving to manned automatic driving, the charge control unit 94 performs NV suppression control CTnv in preparation for manned automatic driving.

[0044] The driving control unit 96 determines whether to transition from unmanned autonomous driving to manned autonomous driving. For example, while unmanned autonomous driving is being performed, the driving control unit 96 determines whether to transition from unmanned autonomous driving to manned autonomous driving by determining whether there is a passenger at the next destination. The next destination is, for example, a location where a passenger accepted by a reservation for a ride in an unmanned taxi will be picked up.

[0045] When the driving control unit 96 determines that the automatic driving control CTad will transition from unmanned automatic driving to manned automatic driving, the charging control unit 94 performs the NV suppression control CTnv during the execution of unmanned automatic driving until manned automatic driving begins.

[0046] The charging control unit 94 acquires the mileage Ddrv from the current location to the location where the vehicle will transition to manned automatic driving while unmanned automatic driving is being performed. The charging control unit 94 also acquires the current state of charge SOCr, which is the current state of charge SOC, while unmanned automatic driving is being performed. The charging control unit 94 calculates the required charging power Pchgdem based on the mileage Ddrv and the current state of charge SOCr while unmanned automatic driving is being performed. For example, the charging control unit 94 calculates the required charging power Pchgdem by applying the mileage Ddrv and the current state of charge SOCr to a predetermined NV priority execution map. The NV priority execution map is a map that prioritizes improving NV performance over improving fuel efficiency after transitioning to manned automatic driving. The NV priority execution map is a predetermined relationship that, for example, sets the state of charge SOC at the start of manned automatic driving to a value greater than the upper limit of a predetermined range of remaining charge RNGsoc. In other words, when the driving control unit 96 determines that the vehicle will transition from unmanned automatic driving to manned automatic driving, the charging control unit 94 performs NV suppression control CTnv so that the remaining charge SOC at the time manned driving begins is greater than the upper limit value of the specified remaining charge range RNGsoc.

[0047] On the other hand, during unmanned automatic driving in which the driving control unit 96 has not yet determined whether to transition to attended automatic driving, or during attended automatic driving, the charging control unit 94 controls the engine 12 so that the state of charge SOC falls within a predetermined range of remaining charge RNGsoc and the energy efficiency of the vehicle 10 is optimized. The predetermined range of remaining charge RNGsoc and the optimal engine operating point are fuel efficiency optimization maps that prioritize improving fuel efficiency. In other words, during unmanned automatic driving in which the driving control unit 96 has not yet determined whether to transition to attended automatic driving, or during attended automatic driving, the charging control unit 94 calculates the required charging power Pchgdem using the fuel efficiency optimization map.

[0048] FIG. 2 is a flowchart illustrating the main control operations of the electronic control unit 90, which are executed repeatedly, for example, to improve NV performance during autonomous driving.

[0049] In FIG. 2, first, in step S10 (hereinafter, "step" will be omitted) corresponding to the function of the driving control unit 96, it is determined whether unmanned automatic driving is being performed. If the determination in S10 is affirmative, it is determined in S20, corresponding to the function of the driving control unit 96, whether there is a passenger at the next destination. If the determination in S20 is affirmative, in S30, corresponding to the function of the charging control unit 94, the travel distance Ddrv from the current location to the destination (the point where the driving mode shifts to manned automatic driving) is acquired, and also the current remaining charge SOCr is acquired. Following S30, in S40, corresponding to the function of the charging control unit 94, the required charging power Pchgdem is calculated using the NV-priority execution map. On the other hand, if the determination in S10 above is negative, or if the determination in S20 above is negative, in S50, corresponding to the function of the charging control unit 94, the required charging power Pchgdem is calculated using the fuel-efficiency-optimized execution map.

[0050] FIG. 3 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 2 is executed. FIG. 3 shows an example when autonomous driving is performed. The comparative example shown by the dashed line shows an example when the engine 12 is controlled so that the state of charge SOC falls within a predetermined range of state of charge RNGsoc and the energy efficiency of the vehicle 10 is optimized. In FIG. 3, time t1 is the time when a passenger is picked up at the destination during unmanned autonomous driving, and is the time when manned autonomous driving is started. As shown by the solid line, the required charging power Pchgdem in unmanned autonomous driving is set to a value greater than the required charging power Pchgdem (see dashed line) using the fuel efficiency optimization execution map until time t1. As a result, the state of charge SOC at time t1 is increased above the upper limit value of the predetermined range of state of charge RNGsoc. Because unmanned autonomous driving is performed until time t1, problems are unlikely to occur even if the engine rotation speed Ne is increased and NV deteriorates. After manned autonomous driving begins, the required charging power Pchgdem is reduced, the engine 12 is stopped, and BEV driving is performed. In this embodiment, the engine 12 is stopped more frequently and the engine rotation speed Ne is reduced compared to the comparative example, thereby improving the NV performance.

[0051] As described above, according to this embodiment, the NV suppression control CTnv is performed during unmanned automatic driving. As a result, the charging power Pchg is increased during unmanned automatic driving, in which deterioration of NV is unlikely to be a problem, and the state of charge SOC at the start of manned automatic driving is increased compared to when manned automatic driving is ongoing. Therefore, after the start of manned automatic driving following unmanned automatic driving, during the period when the state of charge SOC is large, the time the engine 12 is stopped is increased and the engine rotation speed Ne is reduced. This makes it possible to improve NV performance during automatic driving.

[0052] Furthermore, according to this embodiment, when it is determined that the vehicle should be transitioned from unmanned automatic driving to manned automatic driving, the NV suppression control CTnv is performed during the unmanned automatic driving until the manned automatic driving starts. This allows the state of charge SOC at the start of manned automatic driving to be increased appropriately compared to when manned automatic driving is continuing.

[0053] Furthermore, according to this embodiment, the NV suppression control CTnv calculates the required charging power Pchgdem based on the mileage Ddrv and the current state of charge SOCr, and as a result, the required charging power Pchgdem is appropriately set to a larger value during unmanned automatic driving than during manned automatic driving.

[0054] Furthermore, according to this embodiment, during unmanned automatic driving in which transition to manned automatic driving has not been determined, or during manned automatic driving, the engine 12 is controlled so that the state of charge SOC falls within a predetermined range RNGsoc and fuel economy is optimized. This allows appropriate control to be performed that prioritizes improvement of fuel economy performance.

[0055] Furthermore, according to this embodiment, when it is determined that the vehicle will transition from unmanned autonomous driving to manned autonomous driving, the NV suppression control CTnv is performed so that the state of charge SOC at the time manned driving starts is greater than the upper limit of the predetermined range of state of charge RNGsoc. This allows for appropriate execution of control that prioritizes improving NV performance.

[0056] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0057] For example, in the above-described embodiment, the target value of the state of charge SOC at the start of manned driving may be set in advance to a value greater than the upper limit of the predetermined range of state of charge RNGsoc in the NV suppression control CTnv. The NV suppression control CTnv may then calculate the required charging power Pchgdem for increasing the current state of charge SOCr to the target value of the state of charge SOC while traveling the travel distance Ddrv.

[0058] Furthermore, in the above-described embodiments, the present invention can also be applied to a parallel or series hybrid vehicle equipped with an engine and an electric motor as a power source, or a so-called plug-in hybrid vehicle in which the battery can be charged from an external power source such as a charging station or a household power source.

[0059] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0060] 10: Vehicle (hybrid vehicle) 12: Engine 54: Battery 90: Electronic control unit (control unit) 94: Charging control unit 96: Operation control unit MG1: First electric motor (electric motor) MG2: Second electric motor (electric motor)

Claims

1. A control device for a hybrid vehicle including an engine, an electric motor, and a battery that supplies and receives electric power to the electric motor, a driving control unit that executes a manual driving control for driving the hybrid vehicle based on a driving operation by a driver, and an automatic driving control for driving the hybrid vehicle by automatically performing steering and acceleration / deceleration; a charging control unit that performs NV suppression control to set a required charging power for charging the battery by power generation of the electric motor using power of the engine to a larger value during unmanned traveling under the automatic driving control than during manned traveling under the automatic driving control; and the charging control unit performs the NV suppression control during execution of the unmanned traveling until the manned traveling starts when the traveling control unit determines that the unmanned traveling will be transitioned to the manned traveling during the automatic driving control, The control device for a hybrid vehicle is characterized in that the charging control unit calculates the required charging power based on the traveling distance from the current point to the point where the unmanned traveling mode will transition to the manned traveling mode and the current remaining charge of the battery during the unmanned traveling mode.

2. 2. The control device for a hybrid vehicle according to claim 1, wherein the charging control unit controls the engine during the unmanned driving mode when the driving control unit has not determined whether to transition to the manned driving mode, or during the manned driving mode, so that the remaining charge of the battery is within a predetermined remaining charge range and the energy efficiency of the hybrid vehicle is optimized.

3. 3. The hybrid vehicle control device according to claim 2, wherein, when the driving control unit determines that the vehicle will transition from unmanned driving to manned driving, the charging control unit performs the NV suppression control so that the remaining charge at the time the manned driving starts is greater than an upper limit value of the predetermined remaining charge range.

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