VEHICLE AND CONTROL METHOD FOR A VEHICLE

Abstract

Vehicle (10, 100) that features: an internal combustion engine (12, 102); a first rotary machine (MG2, MG) designed to output a drive torque; a battery (52, 120) designed to be charged by the kinetic energy of the internal combustion engine (12, 102) and designed to supply electrical energy to the first rotary engine (MG2, MG); and an electronic control unit (90, 122) designed to selectively perform a first operational control and a second operational control, wherein The first operating control is a control for causing the vehicle (10, 100) to drive on the basis of a driver's driving operation, and the second operating control is a control for automatically setting a target driving state on the basis of at least map information and / or road information and for automatically performing acceleration or deceleration on the basis of the target driving state. the electronic control unit (90, 122) is designed to start the internal combustion engine (12, 102) when a value representing a state of charge of the battery (52, 120) falls below an internal combustion engine start threshold value, while the operation of the internal combustion engine (12, 102) is stopped, and the electronic control unit (90, 122) is designed to ensure that the combustion engine start threshold in the second operating control is lower than the combustion engine start threshold in the first operating control, the second operating control includes an unmanned operating control and a manned operating control, the unmanned operating control being an operating control corresponding to an unmanned journey for automatically performing acceleration or deceleration without occupants in the vehicle (10, 100), and the manned operating control being an operating control corresponding to a manned journey for automatically performing acceleration or deceleration while at least one occupant is present in the vehicle, the electronic control unit (90, 122) is designed to selectively perform unmanned operation control and manned operation control, and the electronic control unit (90, 122) is designed to ensure that the combustion engine start threshold in unmanned operation control is lower than the combustion engine start threshold in manned operation control.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The invention relates to a vehicle comprising an internal combustion engine, a rotary machine and a battery, and a control method for the vehicle. 2. State of the art

[0002] A control device for a vehicle equipped with an internal combustion engine, a rotary machine capable of generating drive torque, and a battery charged by the kinetic energy of the internal combustion engine and supplying electrical energy to the rotary machine is known. A vehicle driving control device described in JP 2012-86771A is an example of this. JP 2012-86771A discloses that frequent starting and stopping of the internal combustion engine during constant-speed driving (also known as coasting) is prevented by starting the internal combustion engine when a value representing the state of charge (SOC) of the battery (also known as the battery SOC value (%)) falls below a combustion engine start threshold during electric motor driving while coasting.Prohibits stopping the internal combustion engine until the battery SOC value is equal to or greater than an internal combustion engine stop threshold at the time of coasting after the internal combustion engine has started (> internal combustion engine stop threshold at the time of normal driving control if coasting is not performed). SUMMARY OF THE INVENTION

[0003] The time during which the internal combustion engine is stopped (also known as the engine stop time) can be extended if the engine start threshold used to determine when the battery state of charge (SOC) has dropped to a level where the engine must be started to recharge the battery is lowered. This contributes to improved fuel economy (also known as improved fuel efficiency). Conversely, if the engine start threshold is lower, there is a greater likelihood that a shock resulting from starting the engine will be due to a lack of electrical output from the battery, attributable to a drop in the battery SOC, or a delay in the engine speed increase during the engine start process (i.e., a slow start).The time required to start the combustion engine is increased), which could lead to a deterioration in driving performance. It is possible to design a vehicle with a first operating control system to ensure the vehicle operates based on driver input, and a second operating control system to allow the vehicle to selectively operate by automatically setting a target driving state based on at least map and / or road information and automatically accelerating / decelerating based on that target driving state.In this vehicle, at the time of the second operating control, the frequency with which a demand for sudden acceleration occurs is low, and the number of situations in which the internal combustion engine is started with high vehicle power is considered smaller than at the time of the first operating control. At the time of the second operating control, it is also possible to assume that a deterioration in driving performance will not be perceived by the driver even if the driving force is reduced when the internal combustion engine is started. Therefore, it is desirable to improve fuel consumption by adjusting the internal combustion engine start threshold taking into account the difference in the operating control, rather than using a method according to which the internal combustion engine start threshold is set uniformly, regardless of the difference in the operating control.

[0004] DE 10 2015 104 691 A1 discloses a vehicle control device comprising: an electric motor connected to wheels, an energy storage device connected to the electric motor, a charging / discharging control device that controls the charging / discharging of the energy storage device, a first driving control device that controls the electric motor according to an operating command from a driver, and a second driving control device that controls the electric motor according to a cruise control function that automatically regulates a vehicle speed. When the first driving control device controls the electric motor, the charging / discharging control device controls the charging / discharging current of the energy storage device within first charging / discharging ranges.When the second drive control device controls the electric motor, the charge / discharge control device controls the charge / discharge current of the energy storage device within second charge / discharge ranges that are further apart than the first charge / discharge ranges.

[0005] EP 2 868 543 A1 discloses a drive device for a hybrid vehicle, comprising: a transmission unit that causes rotation of an internal combustion engine while the speed of the internal combustion engine is changed, and an electric rotary machine that supplies torque to the internal combustion engine via the transmission unit to increase the speed of the internal combustion engine at the time of starting the internal combustion engine, and the transmission unit is switched to a high-speed gear stage at the time of starting the internal combustion engine in a high-load state of the electric rotary machine.

[0006] DE 11 2014 001 065 T5 discloses a control system suitable for controlling a self-driving vehicle along a planned route, wherein the control system is suitable for receiving a friction signal containing information about the friction µ for a road surface on which the vehicle is to travel, and a speed signal containing information about the vehicle speed v. The control system comprises a processing unit and a control unit, wherein the processing unit is suitable for determining a variable safety distance to an object near the vehicle based on the measured friction µ and the vehicle speed v, and for determining a path for the planned route such that the safety distance is maintained.The control unit is further suitable for controlling the vehicle by means of a control signal so that it follows the path by influencing at least the steering and speed of the vehicle by applying a series of control rules, wherein the control rules include a rule which takes into account the lateral acceleration of the vehicle.

[0007] It is an object of the invention to improve fuel consumption (fuel economy) in a vehicle in which a first operating control and a second operating control are selectively implemented. This object is achieved by a vehicle and by a control method for a vehicle with the features of the respective independent claims. The dependent claims are directed to advantageous embodiments of the invention.

[0008] A first aspect of the invention relates to a vehicle. The vehicle comprises an internal combustion engine, a first rotary machine designed to generate drive torque, a battery designed to be charged by means of the kinetic energy of the internal combustion engine and designed to supply electrical energy or power to the first rotary machine, and an electronic control unit. The electronic control unit is designed to selectively perform a first operating control and a second operating control. The first operating control is a control for causing the vehicle to drive based on driver input. The second operating control is a control for automatically setting a target driving state based on at least map information and / or road information and for automatically performing acceleration or deceleration based on the target driving state.The electronic control unit is designed to start the internal combustion engine when a value representing the battery's state of charge falls below an internal combustion engine start threshold, while the engine is stopped. The electronic control unit is designed to ensure that the internal combustion engine start threshold during the second operating control cycle is lower than the threshold during the first operating control cycle.

[0009] With the above configuration, the combustion engine start threshold at the time of the second operational control, during which the vehicle is caused to drive by automatically accelerating or decelerating based on the target driving state (automatically set based on at least map and / or road information), is lower than at the time of the first operational control, during which the vehicle is caused to drive based on driver input. Therefore, the combustion engine stop time at the time of the second operational control, when a deterioration in driving performance resulting from a delay in the increase of the combustion engine speed during the combustion engine start-up process is more difficult for the driver to detect, may be longer than at the time of the first operational control.Therefore, driving efficiency in the vehicle in which the first operating control and the second operating control can be selectively performed can be improved (i.e., fuel consumption can be improved).

[0010] The electronic control unit in the vehicle may be designed to start the internal combustion engine at the time of the second operating control if the drive torque of the first rotating machine is less than an upper limit of the drive torque of the first rotating machine at the time of the first operating control.

[0011] With the configuration described above, the internal combustion engine is started during the second operating control phase if the drive torque of the first rotating machine is less than the upper limit of the drive torque at the time of the first operating control phase. Therefore, starting the internal combustion engine can be delayed even if the battery is overloaded during the second operating control phase, provided the internal combustion engine start threshold is low. This can reduce or prevent battery degradation.

[0012] The electronic control unit in the vehicle may be designed to perform the second operational control by automatically carrying out steering and acceleration or deceleration based on the desired driving condition.

[0013] With the above configuration, the vehicle's journey is achieved by the second operational control system through automatic acceleration or deceleration and steering based on the desired driving condition.

[0014] The electronic control unit in the vehicle may be designed to set the desired driving state by setting at least one of the following in the map information: a desired vehicle speed, a desired vehicle-to-vehicle distance to a vehicle ahead, and a desired location or destination.

[0015] With the above configuration, the target driving state is set by adjusting at least one of the following parameters in the map information: the target vehicle speed, the target vehicle-to-vehicle distance to the vehicle ahead, and the target location. Therefore, the vehicle's movement is appropriately implemented by the second operational control system.

[0016] The vehicle may also include a second rotary machine that generates electrical energy or power, which is used to charge the battery via the kinetic energy of the internal combustion engine, and which rotates the internal combustion engine using electrical energy or power supplied by the battery when the engine is started. The first rotary machine may be designed to deliver the drive torque using the electrical energy supplied by the battery.

[0017] With the configuration described above, the vehicle includes a second rotary engine, which generates the electrical energy used to charge the battery via the kinetic energy of the internal combustion engine and rotates the internal combustion engine using the electrical energy supplied by the battery when the engine is started; and a first rotary engine, which delivers the drive torque using the electrical energy supplied by the battery. Therefore, the internal combustion engine stop time during the second operating control can be longer than during the first operating control by ensuring that the internal combustion engine start threshold is lower during the second operating control than during the first.

[0018] In the vehicle, the first rotary machine can have a function as a generator, which produces the electrical energy with which the battery is charged by the kinetic energy of the internal combustion engine, a function as a starter, which rotates the internal combustion engine by means of the electrical energy supplied by the battery when starting the internal combustion engine, and a function as an electric motor, which outputs the drive torque by means of the electrical energy supplied by the battery.

[0019] With the configurations described above, the first rotary machine functions as a generator, producing the electrical energy used to charge the battery via the kinetic energy of the internal combustion engine; as a starter, rotating the internal combustion engine using the electrical energy supplied by the battery when the engine is started; and as an electric motor, generating the drive torque using the electrical energy supplied by the battery. Therefore, the internal combustion engine stop time during the second operating control phase can be longer than during the first, because the internal combustion engine start threshold is lower during the second operating control phase than during the first.

[0020] The vehicle's second operating control system can include an unmanned operating control and a manned operating control. The unmanned operating control can be configured for an unmanned drive, automatically performing acceleration or deceleration without any occupants in the vehicle. The manned operating control can be configured for a manned drive, automatically performing acceleration or deceleration with at least one occupant in the vehicle. The electronic control unit can be designed to selectively execute the unmanned and manned operating control. The electronic control unit can be configured to ensure that the combustion engine start threshold during unmanned operation is lower than the combustion engine start threshold during manned operation.

[0021] The above configuration results in a lower combustion engine start threshold during unmanned operation than during manned operation. Therefore, the combustion engine stop time can be longer during unmanned operation than during manned operation. Consequently, vehicle efficiency (i.e., fuel consumption) can be improved during unmanned operation if the deterioration in drivability due to a shock resulting from engine start and the deterioration resulting from a delay in the increase in engine speed during the start-up process are considered undetected or undetectable, respectively.

[0022] A second aspect of the invention relates to a control method for a vehicle. The vehicle comprises an internal combustion engine, a first rotary machine designed to output a drive torque, a battery designed to be charged by the kinetic energy of the internal combustion engine and designed to supply electrical energy to the first rotary machine, and an electronic control unit.The control procedure includes: performing a first operational control and a second operational control by the electronic control unit, starting the internal combustion engine by the electronic control unit when a value representing a state of charge of the battery falls below an internal combustion engine start threshold, while the operation of the internal combustion engine is stopped, and causing the internal combustion engine start threshold at a time of the second operational control to be lower than the internal combustion engine start threshold at a time of the first operational control.The first operational control is a control to cause the vehicle to drive based on driver input, and the second operational control is a control to automatically set a target driving state based on at least map information and / or road information and to automatically perform acceleration / deceleration based on the target driving state.

[0023] With the above configuration, the combustion engine start threshold is lower at the time of the second operational control, when the vehicle is driven by automatically accelerating or decelerating based on the target driving state, which is automatically set based on at least map and / or road information, than at the time of the first operational control, when the vehicle is driven based on driver input. Therefore, the combustion engine stop time at the time of the second operational control can be long, as a deterioration in driving performance resulting from a delay in the increase of the combustion engine speed during the combustion engine start-up process is assumed to be more difficult for the driver to detect than at the time of the first operational control. Consequently, vehicle efficiency (i.e.,Fuel consumption) in the vehicle in which the first operating control and the second operating control can be carried out selectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Features, advantages, and the technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements. The drawings show: Fig. 1 a view showing the general configuration of the respective components for the operation of a vehicle for which the invention is used, and a view showing the essential part of a control system and control functions for controlling the respective components; Fig. 2 a nomogram capable of representing relative rotational speeds of respective rotating elements in a planetary gear mechanism, wherein a solid line indicates an exemplary driving condition at the time of an HV driving mode and a dashed line indicates an exemplary driving condition at the time of an EV driving mode; Fig. 3 a view showing an exemplary EV / HV range characteristic field used to effect a switch between an EV drive and an HV drive; Fig. 4 a view showing an exemplary timing diagram to represent a mode of internal combustion engine start that is carried out when the SOC value of a battery drops during manual operation control in accordance with normal driving; Fig. 5 a flowchart that represents the essential part of a control operation of an electronic control unit, that is, a control operation for improving fuel consumption in a vehicle, in which manual operating control and automatic operating control can be selectively carried out; Fig. 6. An exemplary time diagram in the case where the control operation, which is shown in the flowchart of the Fig. 5 is shown, and a view showing a mode of combustion engine start that is carried out when the battery's SOC value drops during automatic operation control according to unmanned driving; and Fig. 7 a view representing the general configuration of a vehicle for which the invention is used and which differs from the vehicle of the Fig. 1 distinguishes. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0025] The embodiments of the invention are described in more detail below with reference to the drawings.

[0026] Fig. Figure 1 is a view that represents the general configuration of the respective components for the operation of a vehicle 10 for which the invention is used, and is a view that represents the essential part of a control system and control functions for controlling the respective components. Fig. In Figure 1, vehicle 10 is a hybrid vehicle equipped with an internal combustion engine 12 and a second rotary machine MG2, which can serve as sources of kinetic energy and power, respectively, capable of generating drive torques. Furthermore, vehicle 10 is equipped with drive wheels 14, a kinetic energy transmission device 16 arranged in a kinetic energy transmission path between the internal combustion engine 12 and the drive wheels 14, and a first rotary machine MG1.

[0027] The internal combustion engine 12 is a familiar type of internal combustion engine, such as a gasoline engine, a diesel engine, or similar. The operating conditions of this internal combustion engine 12, such as the throttle valve opening degree θth, the intake air quantity, the fuel supply quantity, the ignition timing, and similar parameters, are controlled by an electronic control unit 90, which will be described later. Thus, the internal combustion engine torque Te is controlled or regulated as an output torque of the internal combustion engine 12.

[0028] The first rotary machine MG1 and the second rotary machine MG2 are each electric rotary machines that function as both electric motors and generators, and are therefore called motor-generators. The first rotary machine MG1 and the second rotary machine MG2 are each connected to a battery 52, with which the vehicle 10 is equipped, via an inverter 50, with which the vehicle 10 is also equipped. The inverter 50 is controlled by the electronic control unit 90, which will be described later. Thus, an MG1 torque Tg is controlled as an output torque (power operating torque or regenerative torque) of the first rotary machine MG1, and an MG2 torque Tm (power operating torque or regenerative torque) of the second rotary machine MG2 is controlled.

[0029] Inverter 50 controls the output / reception of electrical power for the operation of the first rotating machine MG1 and the second rotating machine MG2 such that the MG1 torque Tg required by the first rotating machine MG1 and the MG2 torque Tm required by the second rotating machine MG2 are obtained. Battery 52 is an electrical storage device that exchanges electrical power with the first rotating machine MG1 and the second rotating machine MG2. More precisely, battery 52 is an electrical storage device capable of storing the electrical energy generated by the first rotating machine MG1 and the second rotating machine MG2 and supplying the stored electrical energy to the first rotating machine MG1 and the second rotating machine MG2, respectively.

[0030] The kinetic energy transmission device 16 is connected to an input shaft 20, which is coupled to the internal combustion engine 12 either directly or indirectly via a damper (not shown) or similar device; a switching unit 22, which is coupled to the input shaft 20; a driven wheel 26, which engages with a drive wheel 24 as an output rotary element of the switching unit 22; a driven shaft 28, which is fixedly and non-rotatably attached to the driven wheel 26; an end wheel 30 (the end wheel 30 has a smaller diameter than the driven wheel 26), which is fixedly and non-rotatably attached to the driven shaft 28; a differential wheel 32, which engages with the end wheel 30 via a differential ring gear 32a; a reduction wheel 34 (the reduction wheel 34 has a smaller diameter than the driven wheel 26), which engages with the driven wheel 26 and is coupled to the second rotary machine MG2. is,and similar components in a housing 18 as a non-rotating element attached to a vehicle body. The kinetic energy transmission device 16 is equipped with an axle 36 and similar components coupled to the differential gear 32. In the kinetic energy transmission device 16 thus constructed, the kinetic energy (which is synonymous with torque or force when no distinction is made between them) output by the internal combustion engine 12 and the kinetic energy output by the second rotary machine MG2 are transmitted to the driven wheel 26 and are successively transmitted from the driven wheel 26 via the end gear 30, the differential gear 32, the axle 36, and similar components to the drive wheels 14. In the kinetic energy transmission device 16, oil that is used,to lubricate and cool respective components of the kinetic energy transmission device 16, such as a planetary gear mechanism 38, ball bearings and the like, supplied by a mechanical oil pump 40 with which the vehicle 10 is equipped and which is coupled to the input shaft 20 so that it is rotated by the internal combustion engine 12.

[0031] The switching unit 22 incorporates the planetary gear mechanism 38 as a kinetic energy distribution mechanism that distributes (or assigns) the kinetic energy transmitted from the internal combustion engine 12 via the input shaft 20 to the first rotary machine MG1 and the drive wheel 24. The planetary gear mechanism 38 is a known single-pinion planetary gear device equipped with a sun gear S, a planet gear P, a carrier gear CA that supports the planet gear P so that the planet gear P can rotate about its axis and about the carrier gear C, and a ring gear R that engages with the sun gear S via the planet gear P, and serves as a differential mechanism that generates a differential action.In the planetary gear mechanism 38, the sun gear S is coupled to the first rotary machine MG1, the carrier gear CA is coupled to the internal combustion engine 12 via the input shaft 20, and the ring gear R is formed on an inner circumferential surface of the drive gear 24.Accordingly, in the vehicle 10, due to a reaction force of the combustion engine torque Te, which is input by the first rotary machine MG1 onto the carrier wheel CA, an HV drive, which will be described later, can be realized by a directly transmitted torque (which is also referred to as directly transmitted combustion engine torque) which is mechanically transmitted to the ring gear R, and the MG2 torque Tm, which is generated by the second rotary machine MG2 by driving the second rotary machine MG2 by means of electrical energy generated by the first rotary machine MG1, which results from the kinetic energy of the combustion engine 12, which is distributed to the first rotary machine MG1.Thus, the switching unit 22 serves as a known electrical differential unit (an electrically continuously variable transmission), whose transmission ratio (speed ratio) is controlled by controlling the inverter 50 by means of the electronic control unit 90, which will be described later, and the operating state of the first rotary machine MG1. Therefore, the second rotary machine MG2 is a rotary machine that can generate a drive torque.

[0032] Fig. Figure 2 is a nomogram that relatively represents the rotational speeds of the three rotating elements RE1, RE2, and RE3 in the planetary gear mechanism 38. In this nomogram, the vertical lines Y1 to Y3 are shown consecutively from left to right on the sheet. The vertical line Y1 indicates a rotational speed of the sun gear S as the second rotating element RE2, which is coupled to the first rotary engine MG1. The vertical line Y2 indicates a rotational speed of the carrier gear CA as the first rotating element RE1, which is coupled to the internal combustion engine (ENG) 12. The vertical line Y3 indicates a rotational speed of the ring gear R as the third rotating element RE3, which rotates integrally with the drive gear 24. The second rotary engine MG2 is coupled to this third rotating element RE3 via the driven gear 26, the reduction gear 34, and similar components. The solid line in Fig. Figure 2 shows exemplary relative speeds of the respective rotating elements in a driving condition at the time of an HV driving mode, which will be described later. The dashed line in Fig. 2 gives exemplary relative velocities of the respective rotating elements in a driving condition at the time of an EV driving mode, which is described later.

[0033] The operation of vehicle 10 in HV driving mode is indicated using the solid line in Fig. 2 described. While the combustion engine torque Te is input to the carrier gear CA, the MG1 torque Tg is input to the sun gear S. In this case, the control for setting an operating point of the combustion engine 12, represented by the combustion engine speed Ne and the combustion engine torque Te, as an operating point corresponding to the best fuel consumption, can be carried out by a power operation control or a reaction force control of the first rotary machine MG1. This hybrid type is called the mechanical subdivision type or subdivision type.

[0034] The operation of vehicle 10 in EV driving mode is indicated by the dashed line in Fig. 2 described. The internal combustion engine 12 is not driven (i.e., the operation of the internal combustion engine 12 has stopped), the first rotary machine MG1 is unloaded, and the internal combustion engine speed Ne is zero. In this case, the operating torque of the second rotary machine MG2 is transmitted to the drive wheels 14 as a drive torque during a forward direction of travel of the vehicle.

[0035] Vehicle 10 is also equipped with the electronic control unit 90, which includes a control device for the vehicle 10 with regard to controlling the internal combustion engine 12, the first rotary machine MG1, the second rotary machine MG2, and similar components. The electronic control unit 90 contains a so-called microcomputer, which is equipped, for example, with a CPU, RAM, ROM, an input / output interface, and similar components. The CPU performs various types of control of the vehicle 10 by processing signals according to a program that is pre-stored in the ROM, using a temporary storage function of the RAM. The electronic control unit 90 includes, as needed, a computer for controlling the internal combustion engine, a computer for controlling the rotary machines, and similar components.

[0036] Various signals and similar items (for example, the internal combustion engine speed Ne, an output speed No as the speed of the drive wheel 24 corresponding to the vehicle speed V, an MG1 speed Ng as the speed of the first rotary machine MG1, an MG2 speed Nm as the speed of the second rotary machine MG2, an accelerator actuation quantity or accelerator pedal actuation quantity θacc as a driver acceleration operating quantity (i.e., an operating quantity of an accelerator pedal) representing the strength of the driver acceleration operation, a throttle valve opening degree θth as an opening degree of an electronic throttle valve, an operating position of a gearshift lever (shift position) POSsh such as "P", "R", "N", "D" or similar, a longitudinal acceleration Gx of the vehicle 10, a lateral acceleration Gy of the vehicle 10, a yaw rate Ryaw as an angular velocity of the vehicle 10 about a vertical axis, an outside air temperature THair around the vehicle 10,a battery temperature THbat of battery 52, a battery charge / discharge current Ibat, a battery voltage Vbat, vehicle environment information lard, a GPS signal (an orbital signal) Sgps, a communication signal Scom, a sailing signal Scrs, an automatic operating selection signal Sauto and similar based on acquisition values ​​obtained from various sensors and similar with which the vehicle 10 is equipped (for example, an internal combustion engine speed sensor 60, an output speed sensor 62, an MG1 speed sensor 64 such as a resolver or similar, an MG2 speed sensor 66 such as a resolver or similar, an accelerator actuation size sensor 68, a throttle opening degree sensor 70, a shift position sensor 72, a G-sensor 74, a yaw rate sensor 76, an outside air temperature sensor 78, a battery sensor 79,A route detection / obstacle detection sensor 80, such as a vehicle-integrated camera or similar device, a GPS antenna 81, an external network communication antenna 82, a coasting switch 83, which allows a driver to adjust the driving mode according to coasting, an automatic operation selector switch 84, which allows the driver to select automatic operation, and similar devices) are supplied to the electronic control unit 90. In addition, various command signals (for example, an internal combustion engine control command signal Se for controlling the internal combustion engine 12, a rotary engine control command signal Smg for operating the inverter 50, which controls the respective rotary engines MG1 and MG2, a communication signal Scom, a steering signal Sste for operating a steering actuator 86, which controls the steering of the wheels (especially the front wheels), a brake signal Sbra for operating a brake actuator 88, which controls a foot brake) are supplied.and similar) into the respective devices with which the vehicle 10 is equipped (for example, an internal combustion engine control device 54 for a throttle actuator, a fuel injection device, an ignition device and similar, the inverter 50, the external network communication antenna 82, the steering actuator 86, the brake actuator 88 and similar) output by the electronic control unit 90.

[0037] The electronic control unit 90 calculates a battery SOC value (%) as a value representing the state of charge (SOC) of the battery 52, based, for example, on the battery charging / discharging current Ibat or similar parameters. The electronic control unit 90 also calculates a chargeable electrical energy (electrical energy that can be input) Win, which indicates the limit of electrical energy that can be input into the battery 52, and a dischargeable electrical energy (electrical energy that can be output) Wout, which indicates the limit of electrical energy that can be output by the battery 52, based, for example, on the battery temperature THbat and the battery SOC value.The rechargeable electrical energy Win and the dischargeable electrical energy Wout decrease, for example, when the battery temperature THbat is in a low temperature range (lower than normal) and decrease when the battery temperature THbat is in a high temperature range (higher than normal). Rechargeable electrical energy Win decreases when the battery state of charge (SOC) increases to a high level, for example. Dischargeable electrical energy Wout decreases when the battery SOC drops to a low level, for example.

[0038] In order to implement control functions for different types of controls in the vehicle 10, the electronic control unit 90 is equipped with an operating control device or an operating control unit 92 and a hybrid control device or a hybrid control unit 94.

[0039] The operating control unit 92 can selectively perform a first operating control to cause the vehicle to drive based on the driver's driving actions, and a second operating control to automatically set a target driving state based on at least map and / or road information and to cause the vehicle 10 to automatically accelerate / decelerate based on the target driving state. The first operating control is an operating control to cause the vehicle to drive through manual operation in accordance with the driver's driving actions. Manual operation is an operating procedure to cause the vehicle 10 to drive through driver-operated driving actions such as accelerator pedal operation, brake operation, steering operation, or similar actions.The second operating control is an operating control for causing the vehicle to operate automatically. Automatic operation is an operating method for causing the vehicle 10 to automatically accelerate / decelerate, brake, steer, and perform similar actions through control carried out by the electronic control unit 90 based on signals, information, and the like from the various sensors, independently of or without driver input (intention). In the present embodiment of the invention, the first operating control is referred to as the manual operating control, and the second operating control is referred to as the automatic operating control.

[0040] The operating control unit 92 performs manual operating control when automatic operation is not selected by the automatic operating selector switch 84. The operating control unit 92 performs manual operating control by controlling the internal combustion engine 12 and the rotary machines MG1 and MG2, respectively, based on the accelerator actuation parameter θacc and similar parameters.

[0041] The operating control unit 92 performs the automatic operation control when automatic operation is selected by the driver using the automatic operation selector switch 84. The operating control unit 92 controls the internal combustion engine 12 and the rotary machines MG1 and MG2, respectively, based on signals, information, and the like from the various sensors, and performs the automatic operation control by operating the steering actuator 86 and the brake actuator 88. More precisely, the operating control unit 92 establishes a target driving state based on at least map information and / or road information and performs the automatic operation control by automatically executing acceleration / deceleration, braking, and steering based on the target driving state.This acceleration / deceleration refers to the acceleration and deceleration of vehicle 10, and this deceleration may include braking. Map information is information about the vehicle's position, road conditions such as curves, gradients, elevation, and the like, a destination route, legal speed limits, weather conditions, and similar information, based, for example, on data stored in a known navigation system and / or information obtained through communication with the vehicle's exterior. Road information is information about lanes on a road, traffic signs on the road, pedestrians on the road, and similar information, obtained, for example, by the route detection / obstacle detection sensor 80 and similar devices.Furthermore, the operating control unit 92 sets the target driving state by setting at least one of the following in the map information: a target vehicle speed, a target vehicle-to-vehicle distance to a vehicle ahead, and a target location.

[0042] The operating control unit 92 can selectively perform manual operating control corresponding to normal driving and manual operating control corresponding to coasting mode. During normal driving, the vehicle is driven by the driver performing driving operations such as accelerator pedal operation, braking, steering, and the like. During coasting mode, the vehicle is driven by performing driving operations other than accelerator pedal operation and braking, such as steering, while control is performed to maintain the target vehicle speed and / or the target vehicle-to-vehicle distance to the vehicle ahead, as set by the driver using the coasting switch 83, without the driver's involvement in accelerator pedal or braking operation.As described above, in the present embodiment of the invention, sailing is an aspect of manual operational control and is not included in automatic operational control.

[0043] The operating control unit 92 can selectively perform automatic operation according to unmanned driving and automatic operation according to manned driving. During unmanned driving, acceleration / deceleration is performed automatically without occupants in the vehicle 10. During manned driving, acceleration / deceleration is performed automatically when at least one occupant is present in the vehicle 10.

[0044] The operating control unit 92 issues commands to the hybrid control unit 94 for controlling the internal combustion engine 12 and the rotary machines MG1 and MG2, respectively. The hybrid control unit 94 comprises an internal combustion engine control device for controlling the operation of the internal combustion engine 12, i.e., an internal combustion engine control unit 95, and a rotary machine control device for controlling the operation of the first rotary machine MG1 and the second rotary machine MG2 via the inverter 50, i.e., a rotary machine control unit 96. The hybrid control unit 94 performs output control of the internal combustion engine 12, the first rotary machine MG1, and the second rotary machine MG2. The control performed by the hybrid control unit 94 is described in more detail below, using a case of manual operating control during normal driving as an example.

[0045] The hybrid control unit 94 calculates the required drive torque of the drive wheels 14 by using the accelerator actuation quantity θacc and the vehicle speed V for a relationship (for example, drive torque characteristic curves) that is obtained and stored in advance through experiments or at a development stage (i.e., determined in advance). In manual operating mode (corresponding to sailing), automatic operating mode (corresponding to unmanned driving), and automatic operating mode (corresponding to manned driving), a required drive torque is calculated to implement the respective operating mode.

[0046] Taking into account the rechargeable electrical energy Win, the dischargeable electrical energy Wout, and similar parameters of the battery 52, the hybrid control unit 94 outputs command signals to control the internal combustion engine 12, the first rotary machine MG1, and the second rotary machine MG2 (internal combustion engine control command signal Se and rotary machine control command signal Smg) such that the required drive torque is achieved. For example, the internal combustion engine control command signal Se is a command value for an internal combustion engine power Pe, representing the power output of the internal combustion engine 12, which produces the internal combustion engine torque Te at the internal combustion engine speed Ne at that time.The rotary machine control command signal Smg, for example, is a command value for the electrical power generated by the first rotary machine MG1, which outputs a reaction torque of the internal combustion engine torque Te (the MG1 torque Tg at the MG1 speed Ng at that time), and is a command value for the electrical power consumed by the second rotary machine MG2, which outputs the MG2 torque Tm at the MG2 speed Nm at that time.

[0047] The hybrid control unit 94 selectively establishes an electric motor driving mode (EV driving mode) and a hybrid driving mode (also referred to as HV driving mode) as a driving mode according to a driving condition. The hybrid control unit 94 establishes the EV driving mode when it is determined that the vehicle condition is in the EV driving range, and establishes the HV driving mode when it is determined that the vehicle condition is in an HV driving range, by using the vehicle speed V and the required drive torque for a relationship (an EV / HV range characteristic field), for example, in a two-dimensional coordinate system that is predetermined and has a transition line (solid line) that separates the EV driving range and the HV driving range, as shown in Fig. Figure 3 shows how the vehicle speed V and the required drive torque are used as variables. Fig. 3. The EV driving range is set as a low-vehicle speed range, in which the vehicle speed V is relatively low, and as a low-drive torque range, in which the required drive torque is relatively low such that it can only be provided by the MG2 torque Tm. The hybrid control unit 94 establishes the HV driving mode when the battery SOC value is lower than a combustion engine start threshold Sengst, even if the vehicle is in the EV driving range. In manual operation control (coasting), automatic operation control (unmanned driving), automatic operation control (manned driving), and manual operation control (normal driving), the EV driving mode and the HV driving mode are established selectively.

[0048] When the EV driving mode is established, the hybrid control unit 94 enables EV driving in which the operation of the combustion engine 12 stops and only the second rotary machine MG2 is used as a source of kinetic energy for driving using the electrical energy or power from the battery 52.

[0049] When the HV driving mode is established, the hybrid control unit 94 transmits a directly transmitted combustion engine torque to the drive wheel 24 by absorbing a reaction force for the kinetic energy of the combustion engine 12 through the generation of electrical energy or power from the first rotating machine MG1, thus enabling HV driving in which torque is transmitted to the drive wheels 14 to cause the vehicle to move by driving the second rotating machine MG2 using the electrical power or energy generated by the first rotating machine MG1. In this HV driving mode, the vehicle can also drive using the electrical energy from the battery 52, to which the drive torque generated by the second rotating machine MG2 is added.As described above, the second rotary machine MG2 is a rotary machine that generates a drive torque through the electrical energy supplied by the battery 52, as also stated above in EV driving mode.

[0050] In the event that the vehicle's state changes from the EV driving range to the HV driving range, or the battery state of charge (SOC) falls below the combustion engine start threshold Sengst when the combustion engine 12 stops operating, the hybrid control unit 94 (specifically the combustion engine control unit 95) establishes the HV driving mode and starts the combustion engine 12. The combustion engine control unit 95 starts the combustion engine 12 by increasing the combustion engine speed Ne through the first rotary engine MG1 and igniting the combustion engine. That is, the combustion engine control unit 95 starts the combustion engine 12 by cranking the combustion engine 12 through the power operation of the first rotary engine MG1.When the internal combustion engine 12 is started because the battery state of charge (SOC) has dropped below the internal combustion engine start threshold, the hybrid control unit 94 causes the first rotary machine MG1 to generate electrical energy using the kinetic energy of the internal combustion engine 12 and stores the electrical energy generated by the first rotary machine MG1 in the battery 52 after the internal combustion engine has finished starting. As described above, the battery 52 is charged by the kinetic energy of the internal combustion engine 12. The first rotary machine MG1 is a rotating machine that generates electrical energy, which is used to charge the battery 52 using the kinetic energy of the internal combustion engine 12, and which rotates the internal combustion engine 12 using the electrical energy supplied by the battery 52 when the internal combustion engine 12 is started.

[0051] When the combustion engine is started by the first rotary machine MG1, the hybrid control unit 94 causes the second rotary machine MG2 to output a reaction force to counteract the torque, thus preventing the drive torque from dropping due to the reaction force for the cranking torque of the first rotary machine MG1. Therefore, during EV driving mode, it is necessary to ensure an electrical output energy or power from the battery 52 to generate the cranking torque of the first rotary machine MG1 and the reaction force that counteracts the torque of the second rotary machine MG2 in preparation for starting the combustion engine.If the electrical output of battery 52 required to start the internal combustion engine is not guaranteed when the engine is started, some of the battery's electrical output will be used to generate the drive torque to start the engine. This will result in a jolt when the engine starts, potentially impairing driving performance. Alternatively, if the electrical output of battery 52 required to start the engine is not guaranteed when the engine starts, the increase in the engine speed Ne during the starting process will be delayed (i.e., it will take a long time for the engine to start), potentially impairing driving performance.For this reason, an upper limit drive torque in the EV driving range (in other words, an upper limit of the MG2 torque Tm that may be generated as drive torque during EV driving mode) is determined in advance, taking into account the electrical output power of battery 52 required to start the internal combustion engine (i.e., in such a way as to prevent a deterioration in driving performance when the internal combustion engine is started). As described above, the dischargeable electrical energy Wout decreases when the battery SOC value drops into the low range. When the dischargeable electrical energy Wout decreases, it becomes difficult to guarantee the electrical output power of battery 52 required to start the internal combustion engine. Therefore, the battery SOC value must be increased by charging battery 52.For this reason, the combustion engine start threshold Sengst is determined in advance as a lower limit of the battery SOC value to ensure the electrical output power of battery 52 required to start the combustion engine, in such a way as to prevent a deterioration of driving performance when the combustion engine is started. In other words, the combustion engine start threshold Sengst is a threshold that is determined in advance to establish that the battery SOC value necessitates charging battery 52 by forcibly starting the combustion engine 12.

[0052] Fig. Figure 4 is a view that presents an example timing diagram illustrating the mode of an internal combustion engine start, which is performed when the battery's state of charge (SOC) drops during manual operation control, corresponding to normal driving. Fig. 4. Time t1 indicates the point in time at which the combustion engine 12 begins to start because the battery state of charge (SOC) has dropped below the combustion engine start threshold Sengst when the combustion engine 12 stops operating (see Section A). The combustion engine speed Ne is increased by the cranking action of the first rotary machine MG1, and the combustion engine 12 is ignited (see section from time t1 to time t2). During this combustion engine start process, the electrical output energy or power of the battery 52 required to start the combustion engine is ensured. Therefore, the combustion engine speed Ne increases rapidly, the longitudinal acceleration Gx does not fluctuate, and no shock occurs as a result of the combustion engine start.Time t2 indicates the point in time at which autonomous operation of the combustion engine 12 becomes possible after ignition, a forced start of the combustion engine 12 is completed, and the generation of electrical energy by the first rotary machine MG1 is initiated by the kinetic energy of the combustion engine 12 to start charging the battery 52 (see Section B). After charging of the battery 52 has started, the battery state of charge (SOC) increases (see section from time t2).

[0053] If the internal combustion engine start threshold (Sengst) is set low, the internal combustion engine stop time can be extended by lengthening the EV driving mode period, thus improving fuel consumption (vehicle efficiency). However, if the internal combustion engine start threshold is set low, driving performance may deteriorate due to a deficit in the battery's electrical output resulting from a drop in the battery's state of charge (SOC). Furthermore, it is assumed that the degree to which the driver perceives a deterioration in driving performance differs depending on whether manual or automatic driving control is used.Thus, in the present embodiment of the invention, fuel consumption is improved by adjusting the combustion engine start threshold Sengst taking into account the differences in the operating control of the vehicle 10, instead of the combustion engine start threshold Sengst being set uniformly independently of the differences in the operating control of the vehicle 10.

[0054] In order to realize the setting of the combustion engine start threshold Sengst taking into account the above differences in the operating control of the vehicle 10, the electronic control unit 90 is also equipped with a driving condition determination device or a driving condition determination unit 98 and a start threshold setting device or a start threshold setting unit 99.

[0055] The driving state determination unit 98 determines whether automatic operating control is being carried out. If it is determined that automatic operating control is being carried out, the driving state determination unit 98 determines whether the vehicle is operating in an unmanned mode. If it is determined that automatic operating control is not being carried out (i.e., if it is determined that manual operating control is being carried out), the driving state determination unit 98 determines whether the vehicle is operating in a coasting mode.

[0056] When the driving state determination unit 98 determines that automatic operation control is being performed and that the vehicle is operating in unmanned mode (i.e., during the time of automatic operation control corresponding to unmanned driving), the start threshold setting unit 99 sets an internal combustion engine start threshold Sengst1 (during unmanned driving) as the internal combustion engine start threshold Sengst. When the driving state determination unit 98 determines that automatic operation control is being performed and that the vehicle is not operating in unmanned mode (i.e., during the time of automatic operation control corresponding to manned driving), the start threshold setting unit 99 sets an internal combustion engine start threshold Sengst2 (during automatic manned driving) as the internal combustion engine start threshold Sengst.If the driving state determination unit 98 determines that automatic operation control is not being performed and that the vehicle is in coasting mode (i.e., during manual operation control corresponding to coasting), the start threshold setting unit 99 sets an internal combustion engine start threshold Sengst3 (during coasting) as the internal combustion engine start threshold Sengst. If the driving state determination unit 98 determines that automatic operation control is not being performed and that the vehicle is not in coasting mode (i.e., during manual operation control corresponding to normal driving), the start threshold setting unit 99 sets an internal combustion engine start threshold Sengst4 (during normal driving) as the internal combustion engine start threshold Sengst.

[0057] During automatic operation, particularly during unmanned driving, it is assumed that a deterioration in driving performance due to a shock from starting the internal combustion engine, and a deterioration in driving performance due to a delay in the increase of the internal combustion engine speed Ne during the starting process, will not be detected. Therefore, during unmanned driving, fuel consumption is prioritized. The start threshold setting unit 99 sets the internal combustion engine start threshold Sengst1 (during unmanned driving) to a lower value than the internal combustion engine start threshold Sengst2 (during automatic manned driving), the internal combustion engine start threshold Sengst3 (during coasting), and the internal combustion engine start threshold Sengst4 (during normal driving).As described above, the start threshold setting unit 99 causes the combustion engine start threshold Sengst to be lower in automatic operation control (especially during unmanned driving) than in manual operation control. The start threshold setting unit 99 ensures that the combustion engine start threshold Sengst is lower in automatic operation control corresponding to unmanned driving than in automatic operation control corresponding to manned driving.

[0058] During automatic operation, corresponding to manned driving, it can be assumed that the driver's sensitivity to a shock is higher and that a deterioration in driving performance due to a shock resulting from starting the combustion engine is more easily recognizable than with manual operation. Therefore, this automatic operation prioritizes damping the shock resulting from starting the combustion engine. The start threshold setting unit 99 sets the combustion engine start threshold Sengst2 (during automatic manned driving) higher than the combustion engine start threshold Sengst3 (during coasting) and the combustion engine start threshold Sengst4 (during normal driving).

[0059] During coasting in manual mode, it can be assumed that the driver's sensitivity to shocks is higher, and a deterioration in driving performance due to a shock resulting from starting the internal combustion engine is more easily detectable than during normal driving in manual mode. Therefore, in coasting mode, the manual control prioritizes damping the shock resulting from starting the internal combustion engine. The start threshold setting unit 99 sets the internal combustion engine start threshold Sengst3 (during coasting) to a higher value than the internal combustion engine start threshold Sengst4 (during normal driving).

[0060] The relationship between the combustion engine start thresholds Sengst of the respective types of vehicle operating controls 10 is determined such that combustion engine start threshold Sengst1 (during unmanned driving) < combustion engine start threshold Sengst4 (during normal driving) < combustion engine start threshold Sengst3 (during coasting) < combustion engine start threshold Sengst2 (during automatic manned driving). Fuel consumption has a higher priority when the combustion engine start threshold Sengst is lower. Driving performance (especially shock absorption) has a higher priority when the combustion engine start threshold Sengst is higher.Furthermore, the combustion engine start threshold Sengst4 (during normal driving) can be the same as the combustion engine start threshold Sengst that is predetermined to prevent a deterioration in driving performance when starting the combustion engine, but the invention is not limited to this. The combustion engine start threshold Sengst for each type of operating control can be suitably determined depending on whether fuel consumption or driving performance is more important.

[0061] Note that if the combustion engine start threshold Sengst is reduced to decrease the dischargeable electrical energy Wout of battery 52, the residual electrical energy that can be output by battery 52 during EV driving may decrease, and the load on battery 52 when starting the combustion engine may increase. Conversely, if the drive torque generated by the second rotary machine MG2 is small during the combustion engine 12 start-up process, the residual electrical energy that can be output by battery 52 will increase.Thus, the combustion engine control unit 95 begins to start the combustion engine 12 when the battery state of charge (SOC) has fallen below the combustion engine start threshold Sengst during automatic operation (especially during unmanned driving), when the combustion engine start threshold Sengst is low, when the drive torque generated by the second rotary machine MG2 is low, or when the drive torque generated by the second rotary machine MG2 becomes low. More precisely, during automatic operation (especially during unmanned driving), the combustion engine control unit 95 starts the combustion engine 12 when the MG2 torque Tm generated as drive torque by the second rotary machine MG2 is less than the upper limit of the MG2 torque Tm that may be generated as drive torque during manual operation.

[0062] Fig. Figure 5 is a flowchart that represents the essential part of the control operation of the electronic control unit 90, that is, the control operation for improving fuel consumption in the vehicle 10, in which manual and automatic operating control are selectively carried out. This flowchart is executed repeatedly, for example, while the operation of the internal combustion engine 12 is stopped. Fig. 6 is an exemplary time diagram of the case in which the control operation, which is shown in the flowchart of the Fig. Figure 5 is shown, and is a view showing a mode of combustion engine start that is performed when the battery SOC value drops at the time of automatic operation control according to the unmanned drive.

[0063] In Fig. In step 5 (the word "step" will be omitted hereafter), S10 determines, according to the function of the driving state determination unit 98, whether automatic operation control is being carried out. If the result of the determination in this step S10 is positive, S20 determines, according to the function of the driving state determination unit 98, whether the vehicle is driving in unmanned mode. If the result of the determination in this S20 is positive, the combustion engine start threshold Sengst1 (during unmanned driving) is set as the combustion engine start threshold Sengst in S30, according to the function of the start threshold setting unit 99.During automatic operation, corresponding to unmanned driving, the deterioration of driving performance due to the shock resulting from starting the combustion engine, and the deterioration of driving performance resulting from a delay in the increase of the combustion engine speed Ne during the starting process, are detected less than during manual operation, corresponding to normal driving. Therefore, the combustion engine start threshold Sengst1 (during unmanned driving) is set to a low value to improve fuel consumption. If the result of the determination in S20 above is negative, the combustion engine start threshold Sengst2 (during automatic manned driving) is set in S40 according to the function of the start threshold setting unit 99.During automatic operation control corresponding to manned driving, the deterioration of driving performance due to the shock resulting from starting the internal combustion engine, and the deterioration of driving performance resulting from a delay in the increase of the internal combustion engine speed Ne during the starting process, are more noticeable than during automatic operation control corresponding to unmanned driving. Therefore, the internal combustion engine start threshold Sengst2 (during automatic manned driving) is set to a high value to improve driving performance. Conversely, if the result of the determination in S10 above is negative, S50 determines, according to the function of the driving state determination unit 98, whether the vehicle is in coasting mode.If the result of the determination in S50 is positive, the internal combustion engine start threshold Sengst3 (during coasting) is set as the internal combustion engine start threshold Sengst in S60, according to the function of the start threshold setting unit 99. During manual operation (during coasting), the deterioration in handling due to the shock resulting from starting the internal combustion engine is more noticeable than during manual operation (during normal driving). Therefore, the internal combustion engine start threshold Sengst3 (during coasting) is set to a high value to improve handling. If the result of the determination in S50 above is negative, the internal combustion engine start threshold Sengst4 (during normal driving) is set as the internal combustion engine start threshold Sengst in S70, according to the function of the start threshold setting unit 99.In manual operation control according to normal driving, the combustion engine start threshold Sengst, which is determined in advance to prevent a deterioration of driving performance when starting the combustion engine, is set as combustion engine start threshold Sengst4 (during normal driving).

[0064] In Fig. 6. During automatic operation, the combustion engine start threshold Sengst1 (during unmanned operation) is set lower than the combustion engine start threshold Sengst4 (during normal operation) in accordance with the unmanned operation control, such that the combustion engine 12 is prevented from starting as far as possible when the battery SOC value drops, and in such a way as to improve fuel consumption. If the operation of the combustion engine 12 stops, a start attempt is initiated when the battery SOC value has dropped below the combustion engine start threshold Sengst1 (during unmanned operation) (see time t1), and the combustion engine 12 is ignited after the combustion engine speed Ne is increased by cranking by the first rotary engine MG1 (see section from time t1 to time t2) (see Section A).Since the combustion engine start threshold Sengst1 (during unmanned driving) is a small value, it is difficult to guarantee the electrical output energy of the battery 52 required to start the combustion engine. Therefore, during this combustion engine start process, the longitudinal acceleration Gx fluctuates when attempting to rapidly increase the combustion engine speed Ne, resulting in a jolt. Due to the unmanned driving mode, any deterioration in driving performance caused by this jolt is not detected. Fuel consumption is improved by the small combustion engine start threshold Sengst1 (during unmanned driving).Once the combustion engine has been ignited, autonomous operation of the combustion engine 12 is possible, and a forced start of the combustion engine 12 is terminated. Furthermore, charging of the battery 52 begins after the first rotary machine MG1 starts generating electrical energy using the kinetic energy of the combustion engine 12 (see time t2), and the battery's state of charge (SOC) is increased (see section from time t2 onwards) (see Section B).

[0065] As described above, according to the present embodiment of the invention, during automatic operation control, where the vehicle is driven by automatically performing acceleration / deceleration based on the target driving state, which is automatically set based on at least map and / or road information, the combustion engine start threshold Senst is set to a lower value than during manual operation control, where the vehicle is driven based on the driver's driving behavior. Therefore, the combustion engine stop time during automatic operation control can be long, making any deterioration in driving performance resulting from a delay in the increase of the combustion engine speed Ne during the combustion engine start process more difficult for the driver to detect than during manual operation control.Therefore, the vehicle efficiency (i.e., fuel consumption) in vehicle 10 can be improved by selectively performing the first operational control and the second operational control.

[0066] According to the present embodiment of the invention, the internal combustion engine 12 is started during automatic operation control if the MG2 torque Tm, which is generated as drive torque by the second rotary machine MG2, is less than the upper limit of the MG2 torque Tm that may be generated as drive torque during manual operation control. Therefore, starting the internal combustion engine with an overloaded battery 52 during automatic operation control can be prevented if the internal combustion engine start threshold Sengst is low. Thus, deterioration of the battery 52 can be limited.

[0067] According to the present embodiment of the invention, the vehicle's operation is achieved by means of automatic control through automatic acceleration / deceleration and steering based on the desired driving state.

[0068] According to the present embodiment of the invention, the desired driving state is set by adjusting at least one of the following parameters in map information: the desired vehicle speed, the desired vehicle-to-vehicle distance to the vehicle ahead, and the desired location. Therefore, the vehicle's movement is suitably implemented by means of automatic control.

[0069] According to the present embodiment of the invention, the combustion engine start threshold Senst is set lower during automatic operation control corresponding to unmanned driving than during automatic operation control corresponding to manned driving. Therefore, the combustion engine stop time can be set longer during automatic operation control corresponding to unmanned driving than during automatic operation control corresponding to manned driving. Consequently, fuel consumption during automatic operation control corresponding to unmanned driving can be improved if a deterioration in driving performance due to a shock resulting from starting the combustion engine and a deterioration in driving performance resulting from a delay in the increase of the combustion engine speed Ne during the combustion engine start-up process are not detected.

[0070] A further embodiment of the invention is described below. The components that are identical in the embodiments of the invention described below are designated by the same reference numerals, and their description is not repeated.

[0071] In the present embodiment of the invention, a dimensional relationship of the combustion engine start threshold values ​​Sengst of the respective types of operating controls of the vehicle 10 is shown, which differs from that of the above first embodiment of the invention.

[0072] It is assumed that with automatic operating control, a deterioration in driving performance resulting from a delay in the increase of the internal combustion engine speed Ne during the engine start-up process is more difficult to detect than with manual operating control. Therefore, this automatic operating control prioritizes improved fuel consumption. The start threshold setting unit 99 sets the internal combustion engine start threshold Sengst1 (during unmanned driving) and the internal combustion engine start threshold Sengst2 (during automatic manned driving) to lower levels than the internal combustion engine start threshold Sengst3 (during coasting) and the internal combustion engine start threshold Sengst4 (during normal driving), respectively.As described above, the start threshold setting unit 99 causes the internal combustion engine start threshold Sengst to be lower during automatic operation control than during manual operation control.

[0073] It is assumed that during unmanned driving using automatic control, the deterioration in driving performance due to the shock resulting from starting the internal combustion engine, and the deterioration in driving performance resulting from a delay in the increase of the internal combustion engine speed Ne during the starting process, are less noticeable than during manned driving using automatic control. Therefore, this unmanned driving mode prioritizes improved fuel consumption. The start threshold setting unit 99 sets the internal combustion engine start threshold Sengst1 (during unmanned driving) to a lower value than the internal combustion engine start threshold Sengst2 (during automatic manned driving).As described above, the start threshold setting unit 99 causes the combustion engine start threshold Sengst to be lower at the time of automatic operation control corresponding to unmanned driving than at the time of automatic operation control corresponding to manned driving.

[0074] It can be assumed that during sailing with manual control, a deterioration in handling resulting from a delay in the increase of the internal combustion engine speed Ne during the engine start-up process is more difficult to detect than during normal driving with manual control. Therefore, this manual control during sailing prioritizes improved fuel consumption. The start threshold setting unit 99 sets the internal combustion engine start threshold Sengst3 (during sailing) to a lower value than the internal combustion engine start threshold Sengst4 (during normal driving).

[0075] A relationship between the combustion engine start thresholds Sengst under the respective types of vehicle operating controls 10 is determined such that combustion engine start threshold Sengst1 (during unmanned driving) < combustion engine start threshold Sengst2 (during automatic manned driving) < combustion engine start threshold Sengst3 (during coasting) < combustion engine start threshold Sengst4 (during normal driving). Fuel consumption has a higher priority when the combustion engine start threshold Sengst is lower, and driving performance (especially a rapid increase in combustion engine speed Ne during the combustion engine start process) has a higher priority when the combustion engine start threshold Sengst is higher.

[0076] In this embodiment of the invention, a similar effect is achieved as with the first embodiment of the invention described above.

[0077] In the present embodiment of the invention, in Fig. Figure 7 shows, by way of example, a vehicle 100 which differs from the vehicle 10 which is equipped with the switching unit 22 which serves as an electric continuous variable transmission in the first embodiment above.

[0078] In Fig.In Figure 7, vehicle 100 is a hybrid vehicle equipped with an internal combustion engine 102, a rotary machine MG, and a kinetic energy transfer device 104. The internal combustion engine 102 and the rotary machine MG can generate a drive torque. The kinetic energy transfer device 104 is successively equipped, on the side of the internal combustion engine 102, with a clutch K0, a torque converter 108, an automatic transmission 110, and similar components, housed in a casing 106 as a non-rotating element attached to a vehicle body. The kinetic energy transfer device 104 is equipped with a differential gear device 112, an axle 114, and similar components. A pump impeller 108a of the torque converter 108 is coupled to the internal combustion engine 102 via the clutch K0 and is directly coupled to the rotary machine MG.A turbine impeller 108b of the torque converter 108 is directly coupled to the automatic transmission 110. In the kinetic energy transmission device 104, the kinetic energy of the internal combustion engine 102 and / or the kinetic energy of the rotary machine MG is successively transmitted to drive wheels 116, with which the vehicle 100 is equipped, via the clutch K0 (in the case where the kinetic energy of the internal combustion engine 102 is transmitted), the torque converter 108, the automatic transmission 110, the differential gear device 112, the axle 114, and similar components. The vehicle 100 is equipped with an inverter 118, a battery 120, which exchanges electrical energy or power with the rotary machine MG via the inverter 118, and an electronic control unit 122.

[0079] The electronic control unit 122 enables EV driving, in which only the rotary machine MG serves as the kinetic energy source for driving, using electrical energy from the battery 120, with the clutch K0 disengaged and the operation of the internal combustion engine 102 stopped. The electronic control unit 122 can start the internal combustion engine 102 by causing the rotary machine MG to generate cranking torque using electrical energy from the battery 120 while controlling the clutch K0 into engagement. The electronic control unit 122 enables HV driving, in which the internal combustion engine 102 serves as the kinetic energy source for driving, by operating the internal combustion engine 102 with the clutch K0 engaged.In the HV driving mode, which enables high-voltage driving, the electronic control unit 122 can also cause the vehicle to drive using the electrical energy from the battery 120, to which the drive torque generated by the rotary engine MG is also added. Alternatively, it can also cause the rotary engine MG to generate electrical energy from the kinetic energy of the internal combustion engine 102, and the electrical energy generated by the rotary engine MG is stored in the battery 120. As described above, the battery 120 is charged by the kinetic energy of the internal combustion engine 102 and supplies electrical energy to the rotary engine MG.The rotary machine MG has a function as a generator, which produces the electrical energy with which the battery 120 is charged by the kinetic energy of the internal combustion engine 102, a function as a starter, which rotates the internal combustion engine 102 by means of the electrical energy supplied by the battery 120 when starting the internal combustion engine 102, and a function as an electric motor, which generates a driving torque by means of the electrical energy supplied by the battery 120.

[0080] The electronic control unit 122 has similar functions to the respective functions of the operating control unit 92, the hybrid control unit 94 (the internal combustion engine control unit 95 and the rotary engine control unit 96), the driving state determination unit 98 and the start threshold setting unit 99 with which the electronic control unit 90 is equipped in the first embodiment of the invention above. As in the case of the electronic control unit 90, the electronic control unit 122 can set the internal combustion engine start threshold taking into account the differences in the operating controls of the vehicle 100.

[0081] According to the present embodiment of the invention, a similar effect is achieved as with the first embodiment of the invention described above.

[0082] Although the embodiments of the invention have been described in more detail above on the basis of the drawings, the invention can be used for other aspects.

[0083] In each of the above embodiments of the invention, vehicle 10 or 100 is described by way of example, in which automatic operating control can be performed according to unmanned driving, automatic operating control according to manned driving, manual operating control according to gliding, and manual operating control according to normal driving, but the invention is not limited to this aspect. For example, if an aspect of the invention is implemented according to which the internal combustion engine start threshold is made lower during automatic operating control than during manual operating control, any vehicle is suitable in which automatic operating control according to manned driving and manual operating control according to normal driving can be performed.In this case, a relationship between the combustion engine start threshold values ​​Sengst is determined under the respective types of vehicle operating controls such that combustion engine start threshold Sengst2 (during automatic manned driving) < combustion engine start threshold Sengst4 (during normal driving).

[0084] In each of the first and second embodiments of the invention described above, the vehicle 10's kinetic energy transmission device 16 is equipped with the switching unit 22, which comprises the planetary gear mechanism 38 as a single-pinion planetary gear device and serves as an electric continuous variable transmission. However, the invention is not limited to this aspect. For example, the kinetic energy transmission device 16 can be equipped with an automatic transmission arranged in series with the switching unit 22 in the kinetic energy transmission path between the switching unit 22 and the drive wheels 14. Furthermore, the switching unit 22 can be a shifting mechanism whose differential operation is limited by the control of the clutches or brakes coupled to the rotary elements of the planetary gear mechanism 38. Additionally, the planetary gear mechanism 38 can be a double-pinion planetary gear device.Furthermore, the planetary gear mechanism 38 can be a differential gear device in which a pinion, rotated by the internal combustion engine 12, and a pair of bevel gears engaging with the pinion are operably coupled to the first rotary machine MG1 and the drive wheel 24. Furthermore, the planetary gear mechanism 38 can be a mechanism in which an internal combustion engine, a rotary machine, and drive wheels are coupled in a manner that enables the transmission of kinetic energy to rotating elements of two or more planetary gear devices in a configuration in which the planetary gear devices are coupled to one another by one or more of the rotating elements forming the planetary gear devices.

[0085] Furthermore, in the third embodiment of the invention described above, the vehicle 100 can be a vehicle not equipped with the clutch K0 and comprising the internal combustion engine 102 and a rotary machine MG directly coupled to the input side of the torque converter 108. In short, the invention is applicable to any vehicle equipped with an internal combustion engine, a rotary machine capable of generating drive torque, and a battery charged by the kinetic energy of the internal combustion engine and supplying electrical energy to the rotary machine. In the vehicle 100, the torque converter 108 is used as a hydraulic transmission device. However, a different hydraulic transmission device, such as a fluid coupling without torque amplification or similar, could also be used.Furthermore, the torque converter 108 does not necessarily have to be present or can be replaced by a simple clutch.

[0086] In each of the above embodiments of the invention, vehicle 10 or 100 is described by way of example as a vehicle for which the invention is used, but the invention is not limited to this aspect. The vehicle for which the invention is used can be a series-production hybrid vehicle that can achieve EV driving by driving a rotary engine for propulsion using electrical energy from a battery when the internal combustion engine is stopped, in addition to causing a rotary engine to generate electrical energy from the kinetic energy of the internal combustion engine, and storing the electrical energy generated by the rotary engine in the battery.

[0087] The embodiments of the invention have been described above. The invention can be modified in various ways within the scope of the claims.

Claims

[1] Vehicle (10, 100) which has: an internal combustion engine (12, 102); a first rotary machine (MG2, MG) designed to output a drive torque; a battery (52, 120) designed to be charged by the kinetic energy of the internal combustion engine (12, 102) and designed to supply electrical energy to the first rotary engine (MG2, MG); and an electronic control unit (90, 122) designed to selectively perform a first operational control and a second operational control, wherein The first operating control is a control for causing the vehicle (10, 100) to drive on the basis of a driver's driving operation, and the second operating control is a control for automatically setting a target driving state on the basis of at least map information and / or road information and for automatically performing acceleration or deceleration on the basis of the target driving state. the electronic control unit (90, 122) is designed to start the internal combustion engine (12, 102) when a value representing a state of charge of the battery (52, 120) falls below an internal combustion engine start threshold value, while the operation of the internal combustion engine (12, 102) is stopped, and the electronic control unit (90, 122) is designed to ensure that the combustion engine start threshold in the second operating control is lower than the combustion engine start threshold in the first operating control, the second operating control includes an unmanned operating control and a manned operating control, the unmanned operating control being an operating control corresponding to an unmanned journey for automatically performing acceleration or deceleration without occupants in the vehicle (10, 100), and the manned operating control being an operating control corresponding to a manned journey for automatically performing acceleration or deceleration while at least one occupant is present in the vehicle, the electronic control unit (90, 122) is designed to selectively perform unmanned operation control and manned operation control, and the electronic control unit (90, 122) is designed to ensure that the combustion engine start threshold in unmanned operation control is lower than the combustion engine start threshold in manned operation control. [2] Vehicle (10, 100) according to claim 1, wherein the electronic control unit (90, 122) is designed to start the internal combustion engine (12, 102) during the second operating control if the drive torque of the first rotary machine (MG2, MG) is less than an upper limit of the drive torque of the first rotary machine during the first operating control. [3] Vehicle (10, 100) according to claim 1 or 2, wherein the electronic control unit (90, 122) is designed to perform the second operational control by automatically performing steering and acceleration or deceleration based on the desired driving state. [4] Vehicle (10, 100) according to one of claims 1 to 3, wherein the electronic control unit (90, 122) is designed to set the target driving state by setting at least one of a target vehicle speed, a target vehicle-to-vehicle distance to a vehicle ahead and a target location in the map information. [5] Vehicle (100) according to any one of claims 1 to 3, which further comprises: a second rotary machine (MG1) that generates electrical energy with which the battery (52) is charged by the kinetic energy of the internal combustion engine (12), and rotates the internal combustion engine by electrical energy supplied by the battery when the internal combustion engine (12) is started, wherein the first rotary machine (MG2) is designed to output the drive torque through the electrical energy supplied by the battery. [6] Vehicle (100) according to any one of claims 1 to 4, wherein the first rotary machine (MG) has a function as a generator that produces the electrical energy with which the battery (120) is charged by the kinetic energy of the internal combustion engine (102), a function as a starter that rotates the internal combustion engine (102) by means of the electrical energy supplied by the battery (120) when starting the internal combustion engine (102), and a function as an electric motor that outputs the drive torque by means of the electrical energy supplied by the battery (120). [7] Control method for a vehicle (10, 100) comprising an internal combustion engine (12, 102), a first rotary machine (MG2, MG) designed to output a drive torque, a battery (52, 120) designed to be charged by kinetic energy of the internal combustion engine (12, 102) and designed to supply electrical energy to the first rotary machine (MG2, MG), and an electronic control unit (90, 122), wherein the control method comprises: Performing a first operational control and a second operational control by the electronic control unit (90, 122); Starting the internal combustion engine (12, 102) by the electronic control unit (90, 122) when a value representing a state of charge of the battery (52, 120) falls below an internal combustion engine start threshold while the operation of the internal combustion engine (12, 102) is stopped; and The electronic control unit (90, 122) causes the combustion engine start threshold in the second operating control to be lower than the combustion engine start threshold in the first operating control, wherein The first operational control is a control to cause the vehicle (10, 100) to drive on the basis of a driver's driving operation, The second operating control is a control for automatically setting a target driving state based on at least map information and / or road information and for automatically performing acceleration or deceleration based on the target driving state. the second operating control includes an unmanned operating control and a manned operating control, the unmanned operating control being an operating control corresponding to an unmanned journey for automatically performing acceleration or deceleration without occupants in the vehicle (10, 100), and the manned operating control being an operating control corresponding to a manned journey for automatically performing acceleration or deceleration while at least one occupant is present in the vehicle, the unmanned operation control and the manned operation control are selectively carried out by the electronic control unit (90, 122), and The electronic control unit (90, 122) causes the combustion engine start threshold to be lower in the unmanned operating control than the combustion engine start threshold in the manned operating control.

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