Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
  • B60K6/20—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
  • B60K6/42—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs characterised by the architecture of the hybrid electric vehicle
  • B60K6/48—Parallel type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/02—Conjoint control of vehicle sub-units of different type or different function including control of driveline clutches
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/04—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units
  • B60W10/06—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of combustion engines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/04—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units
  • B60W10/08—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of electric propulsion units, e.g. motors or generators
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W20/00—Control systems specially adapted for hybrid vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
  • B60W30/18—Propelling the vehicle
  • B60W30/18009—Propelling the vehicle related to particular drive situations
  • B60W30/18063—Creeping
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
  • B60K6/20—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
  • B60K6/42—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs characterised by the architecture of the hybrid electric vehicle
  • B60K6/48—Parallel type
  • B60K2006/4825—Electric machine connected or connectable to gearbox input shaft
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W20/00—Control systems specially adapted for hybrid vehicles
  • B60W20/40—Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2556/00—Input parameters relating to data
  • B60W2556/45—External transmission of data to or from the vehicle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2710/00—Output or target parameters relating to a particular sub-units
  • B60W2710/08—Electric propulsion units
  • B60W2710/081—Speed
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/62—Hybrid vehicles
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/72—Electric energy management in electromobility

Definitions

• the invention relates to a control device for a vehicle including an engine and an electric motor as driving force sources and, more particularly, to a technique for creep running with the use of the electric motor.
• JP 2001-163071 A describes a vehicle including an engine and an electric motor as driving force sources.
• JP 2001-163071 A describes a technique for stopping both the engine and the electric motor during the stop of the vehicle, causing the vehicle to run by using only the power (which is synonymous with torque and force unless otherwise distinguished) of the electric motor at the start of the vehicle, and shifting into running by using at least the power of the engine by igniting the engine in a relatively low vehicle speed state immediately after the start of the vehicle.
• the invention provides a control device for a vehicle, which is able to improve fuel economy during creep running with the use of an electric motor.
• An aspect of the invention provides a control device for a vehicle including: an engine and an electric motor as driving force sources, the electric motor being provided in a power transmission path between the engine and a drive wheel and coupled to the engine via a clutch, the vehicle being configured to carry out creep running with the use of the electric motor in a state where the clutch is released and to keep a rotation speed of the electric motor at a predetermined rotation speed during creep running with the use of the electric motor.
• the control device sets the rotation speed of the electric motor to a rotation speed lower than a target idle rotation speed of the engine during creep running with the use of the electric motor.
• the control device may set the rotation speed of the electric motor during creep running to a rotation speed lower than a target idle rotation speed of the engine by setting the rotation speed of the electric motor during creep running to a predetermined upper limit rotation speed of the electric motor during creep running when the target idle rotation speed of the engine is higher than or equal to the upper limit rotation speed.
• control device may be able to carry out creep running with the use of the engine in a state where the clutch is engaged, and, when the engine is started during creep running with the use of the electric motor, the control device may set a rotation speed of the engine to a rotation speed of the electric motor during creep running at timing at which engagement of the clutch completes and, after that, may shift into creep running with the use of the engine by gradually increasing the rotation speed of the engine to the target idle rotation speed of the engine.
• the control device may carry out regeneration of the electric motor from power of the engine when the rotation speed of the engine is lower than a predetermined lower limit rotation speed at or above which the engine is autonomously operable.
• the control device may set the rotation speed of the electric motor during creep running to the target idle rotation speed of the engine until the clutch is released, and may gradually decrease the rotation speed of the engine toward an upper limit rotation speed of the electric motor during creep running when the rotation speed of the engine has decreased to a rotation speed lower than the rotation speed of the electric motor during creep running.
• FIG. 1 is a view that illustrates the schematic configuration of a drive line provided in a vehicle to which the invention is applied and is a view that illustrates a relevant portion of a control system in the vehicle;
• FIG. 2 is a functional block diagram that illustrates a relevant portion of control functions of an electronic control unit
• FIG. 3 is a view that shows an example of the correlation between a target idle rotation speed of an engine and an MG idle rotation speed during EV creep running;
• FIG. 4 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit, that is, control operations for improving fuel economy during EV creep running;
• FIG. 5 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit, that is, control operations for improving fuel economy during EV creep running, and is another embodiment corresponding to FIG. 4;
• FIG. 6 is an example of a time chart in the case where the control operations shown in the flowchart of FIG. 5 are executed;
• FIG. 7 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit, that is, control operations for improving fuel economy during EV creep running, and is another embodiment corresponding to FIG. 5;
• FIG. 8 is an example of a time chart in the case where the control operations shown in the flowchart of FIG. 7 are executed;
• FIG. 9 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit, that is control operations for improving fuel economy during EV creep running, and is another embodiment corresponding to FIG. 4;
• FIG. 10 is an example of a time chart in the case where the control operations shown in the flowchart of FIG. 9 are executed.
• the vehicle includes a transmission in a power transmission path between the engine (or the electric motor) and the drive wheel.
• the transmission is a manual transmission, such as a known synchromesh parallel-two-shaft transmission including a plurality of pairs of constant-mesh transmission gears between the two shafts, various automatic transmissions (a planetary gear automatic transmission, a synchromesh parallel-two-shaft automatic transmission, a DCT, a CVT, and the like), or the like.
• Each of the automatic transmissions is formed of an automatic transmission alone, an automatic transmission including a fluid transmission device, an automatic transmission including an auxiliary transmission, or the like.
• the fluid transmission device includes a lockup clutch
• the lockup clutch is desirably released or slipped during the idle operation.
• the engine is, for example, an internal combustion engine, such as a gasoline engine and a diesel engine, that generates power through combustion of fuel.
• the clutch provided in a power transmission path between the engine and the electric motor is a wet-type or dry-type engagement device.
• FIG. 1 is a view that illustrates the schematic configuration of a drive line 12 provided in a vehicle 10 to which the invention is applied and is a view that illustrates a relevant portion of a control system for various controls in the vehicle 10.
• the vehicle 10 is a hybrid vehicle that includes an engine 14 and an electric motor MG as driving force sources.
• the drive line 12 includes an engine separating clutch K0 (hereinafter, referred to as separating clutch K0), a torque converter 16, an automatic transmission 18, and the like, in order from the engine 14 side inside a transmission case 20.
• the torque converter 16 serves as a fluid transmission device.
• the transmission case 20 serves as a non-rotating member.
• the drive line 12 includes a propeller shaft 26, a differential gear 28, a pair of axles 30, and the like.
• the propeller shaft 26 is coupled to a transmission output shaft 24 that is an output rotating member of the automatic transmission 18.
• the differential gear 28 is coupled to the propeller shaft 26.
• the pair of axles 30 are coupled to the differential gear 28.
• a pump impeller 16a of the torque converter 16 is coupled to an engine coupling shaft 32 via the separating clutch K0, and is directly coupled to the electric motor MG.
• a turbine impeller 16b of the torque converter 16 is directly coupled to a transmission input shaft 34 that is an input rotating member of the automatic transmission 18.
• a mechanical oil pump 22 is coupled to the pump impeller 16a.
• the mechanical oil pump 22 generates operating hydraulic pressure for carrying out shift control over the automatic transmission 18, engagement/release control over the separating clutch K0, and the like, by being rotational ly driven by the engine 14 (and/or the electric motor MG).
• the thus configured drive line 12 is, for example, suitably used in the FR vehicle 10.
• the power (which is synonymous with torque and force unless otherwise distinguished) of the engine 14 is transmitted from the engine coupling shaft 32 to a pair of drive wheels 36 sequentially via the separating clutch K0, the torque converter 16, the automatic transmission 18, the propeller shaft 26, the differential gear 28, the pair of axles 30, and the like, when the separating clutch KO is engaged.
• the engine coupling shaft 32 couples the engine 14 to the separating clutch K0. In this way, the drive line 12 constitutes a power transmission path from the engine 14 to the drive wheels 36.
• the automatic transmission 18 is a transmission that constitutes part of the power transmission path between both the engine 14 and the electric motor MG and the drive wheels 36 and that transmits power from the driving force sources (the engine 14 and the electric motor MG) to the drive wheels 36 side.
• a predetermined speed position is established on the basis of driver's accelerator operation, a vehicle speed V, and the like, by controlling a hydraulic actuator with the use of a hydraulic control circuit 50.
• the electric motor MG is a so-called motor generator having the function of a motor that generates mechanical power from electric energy and the function of a generator that generates electric energy from mechanical energy.
• the electric motor MG functions as the driving force source that generates running power instead of the engine 14 that is a power source or in addition to the engine 14.
• the electric motor MG is provided in the power transmission path between the engine 14 and the drive wheels 36, and carries out the following operations. That is, the electric motor MG, for example, generates electric energy through regeneration from power generated by the engine 14 or driven force that is input from the drive wheels 36 side, and stores the electric energy in an electrical storage device 54 via an inverter 52.
• the electric motor MG is coupled to the power transmission path between the separa ing clutch KO and the torque converter 16. Power is transmitted to each other between the electric motor MG and the pump impeller 16a.
• the electric motor MG is coupled to the engine 14 via the separating clutch KO, and is coupled to the transmission input shaft 34 of the automatic transmission 18 such that power is transmittable without passing through the separating clutch KO.
• the separating clutch K0 is, for example, a wet-type multi-disc friction engagement device in which a plurality of mutually stacked friction plates are pressed by the hydraulic actuator.
• the separating clutch K0 undergoes engagement/release control from the hydraulic control circuit 50 by using hydraulic pressure that is generated by the oil pump 22 as a source pressure.
• a torque capacity (hereinafter, referred to as K0 torque) of the separating clutch K0 is changed by regulating a linear solenoid valve, or the like, in the hydraulic control circuit 50.
• K0 torque a torque capacity of the separating clutch K0
• the pump impeller 16a and the engine 14 are integrally rotated via the engine coupling shaft 32.
• the separating clutch K0 in a released state of the separating clutch K0, transmission of power between the engine 14 and the pump impeller 16a is interrupted. That is, the engine 14 and the drive wheels 36 are disconnected from each other by releasing the separating clutch K0. Because the electric motor MG is coupled to the pump impeller 16a, the separating clutch K0 also functions as a clutch that is provided in the power transmission path between the engine 14 and the electric motor MG and that connects or interrupts the power transmission path.
• the vehicle 10 includes an electronic control unit 80 that includes a control device for the vehicle 10, which is associated with creep running with the use of the electric motor MG, or the like.
• the electronic control unit 80 is, for example, configured to include a so-called microcomputer including a CPU, a RAM, a ROM, an input/output interface, and the like.
• the CPU executes various controls over the vehicle 10 by carrying out signal processing in accordance with a program prestored in the ROM while utilizing the temporary storage function of the RAM.
• the electronic control unit 80 is configured to execute output control over the engine 14, drive control over the electric motor MG, including regenerative control over the electric motor MG, shift control over the automatic transmission 18, torque capacity control over the separating clutch K0, and the like.
• the electronic control unit 80 is formed separately in a unit for engine control, a unit for electric motor control, a unit for hydraulic pressure control, and the like, as needed.
• Various signals based on detected values of various sensors are supplied to the electronic control unit 80.
• the various sensors include an engine rotation speed sensor 56, a turbine rotation speed sensor 58, an output shaft rotation speed sensor 60, an electric motor rotation speed sensor 62, an accelerator operation amount sensor 64, a coolant temperature sensor 66, a battery sensor 68, and the like.
• the various signals include an engine rotation speed Ne that is the rotation speed of the engine 14, a crank angle Acr, a turbine rotation speed Nt, that is, a transmission input rotation speed Nin that is the rotation speed of the transmission input shaft 34, a transmission output rotation speed Nout that is the rotation speed of the transmission output shaft 24 and corresponds to a vehicle speed V, an electric motor rotation speed (motor rotation speed, MG rotation speed) Nm that is the rotation speed of the electric motor MG, an accelerator operation amount Oacc corresponding to a driver's drive request amount to the vehicle 10, a coolant temperature THeng that is the temperature of coolant of the engine 14 and corresponds to the temperature of the engine 14, a temperature THb, charging/discharging current lb and voltage Vb of the electrical storage device 54, and the like.
• an engine output control command signal Se for output control over the engine 14 an electric motor control command signal Sm for controlling the operation of the electric motcr MG, hydraulic pressure command signals Sp for operating electromagnetic valves (solenoid valves), and the like, included in the hydraulic control circuit 50 for controlling the hydraulic actuators of the separating clutch K0 and automatic transmission 18, and the like, are respectively output from the electronic control unit 80 to an engine control device, such as a throttle actuator and a fuel injection device, the inverter 52, the hydraulic control circuit 50, and the like.
• an engine control device such as a throttle actuator and a fuel injection device, the inverter 52, the hydraulic control circuit 50, and the like.
• a charged amount (state of charge) SOC, chargeable power Win and dischargeable power Wout of the electrical storage device 54 are calculated by the electronic control Unit 80 on the basis of, for example, the temperature THb, charging/discharging current lb and voltage Vb of the electrical storage device 54, and each of those calculated values is used in various controls as one of the above-described various signals.
• FIG. 2 is a functional block diagram that illustrates a relevant portion of control functions of the electronic control unit 80.
• shift control means that is, a shift control unit 82, determines whether to shift the automatic transmission 18 on the basis of, for example, a vehicle state (for example, an actual vehicle speed V, an actual accelerator operation amount Oacc, and the like) by consulting a known correlation (shift line map, shift map (not shown)) obtained through an experiment or design and stored in advance (that is, predetermined) by using a vehicle speed V and a drive request amount (for example, accelerator operation amount Oacc, or the like) as variables, outputs a shift command value for obtaining the determined speed position (speed ratio) to the hydraulic control circuit 50, and executes automatic shift control over the automatic transmission 18.
• the shift command value is one of the hydraulic pressure command signals Sp.
• Hybrid control means that is, a hybrid control unit 84, has the function of an engine drive control unit that executes drive control over the engine 14 and the function of an electric motor operation control unit that controls the operation of the electric motor MG as a driving force source or a generator via the inverter 52, and executes hybrid drive control, or the like, with the use of the engine 14 and the electric motor MG through those control functions.
• the hybrid control unit 84 calculates a required driving torque Tdtgt as the drive request amount that is required for the vehicle 10 by a driver on the basis of the accelerator operation amount Oacc and the vehicle speed V.
• the command signals (the engine output control command signal Se and the electric motor control command signal Sm) are output for controlling the driving force sources so as to obtain the output torques of the driving force sources (the engine 14 and the electric motor MG), which achieve the required driving torque Tdtgt.
• the drive request amount may be a required driving force N] of the drive wheels 36, a required driving power [W] of the drive wheels 36, a required transmission output torque Touttgt of the transmission output shaft 24, a required transmission input torque Tintgt of the transmission input shaft 34, or the like.
• the drive request amount may also be merely the accelerator operation amount Oacc [%], a throttle valve opening degree [%], an intake air amount [g/sec], or the like.
• the hybrid control unit 84 sets a traveling mode to a motor running mode (hereinafter, EV mode), and carries out motor running (EV traveling) in which the vehicle travels while transmitting running torque to the drive wheels 36 with the use of only the electric motor MG in a state where the separating clutch K0 is released.
• a traveling mode hereinafter, EV mode
• EV traveling motor running
• the hybrid control unit 84 sets the traveling mode to an engine running mode, that is, a hybrid traveling mode (hereinafter, EHV mode), and carries out engine running, that is, hybrid traveling (EHV traveling) in which the vehicle travels with the use of at least the engine 14 as the driving force source in a state where the separating clutch K0 is engaged.
• EHV mode hybrid traveling mode
• EHV traveling hybrid traveling
• the hybrid control unit 84 carries out EHV traveling.
• EHV traveling EHV mode
• the engine torque Te is not required as the running torque, so the separating clutch K0 does not always need to be engaged.
• the hybrid control unit 84 starts the engine 14 when the hybrid control unit 84 changes the traveling mode from the EV mode to the EHV mode.
• the engine rotation speed Ne is increased by setting the released separating clutch K0 in the slipped or engaged state (in other words, by rotationally driving the engine 14 with the use of the electric motor MG), and the engine 14 is started by starting engine ignition, fuel supply, and the like.
• the hybrid control unit 84 stops the engine 14 when the hybrid control unit 84 changes the traveling mode from the EHV mode to the EV mode.
• the engine 14 is stopped by stopping supply of fuel to the engine 14, and the like, and the separating clutch K0 is released when the separating clutch K0 is engaged.
• the engine 14 is caused to stop its rotation in the result, and the engine rotation speed Ne is decreased.
• the vehicle 10 is able to carry out known creep running with the use of the engine 14 (engine creep running) and is also able to carry out creep running with the use of the electric motor MG (motor creep running, EV creep running).
• the hybrid control unit 84 carries out EV creep running in a state where the separating clutch K0 is released, and keeps the MG rotation speed Nm at a predetermined rotation speed during the EV creep running.
• the hybrid control unit 84 carries out engine creep running in a state where the separating clutch K0 is engaged, and keeps the engine rotation speed Ne at a predetermined rotation speed during the engine creep running.
• the predetermined rotation speed that is the MG rotation speed Nm during EV creep running is termed an idle rotation speed Nmi of the electric motor MG
• the predetermined rotation speed that is the engine rotation speed Ne during engine creep running is termed an idle rotation speed Nei of the engine 14.
• the engine idle rotation speed Nei is, for example, controlled to the set target value of the engine idle rotation speed Nei (a target idle rotation speed Neii of the engine 14).
• the target idle rotation speed Neii is, for example, set on the basis of the coolant temperature THeng of the engine 14, the magnitude of an auxiliary load, and the like.
• the target idle rotation speed Neii is increased as compared to that during steady operation, such as after completion of warm-up, during a stop of the air-conditioner, or the like.
• the MG idle rotation speed Nmi is adjusted to the target idle rotation speed Neii.
• the target idle rotation speed Neii is increased, the MG idle rotation speed Nmi is also increased, so the amount of electric power consumed by the electric motor MG is relatively large.
• the hybrid control unit 84 sets the MG idle rotation speed Nmi to a rotation speed lower than the target idle rotation speed Neii of the engine 14.
• a step in driving force between EV creep running and engine creep running does not become large (in other words, a difference between the MG idle rotation speed Nmi and the target idle rotation speed Neii does not become large). That is, it is desired to set the MG idle rotation speed Nmi in consideration of suppressing the amount of electric power consumed and generation of a step in driving force as a result of decreasing the MG idle rotation speed Nmi.
• the hybrid control unit 84 sets the MG idle rotation speed Nmi during EV creep running to the predetermined value Nmimx, thus setting the MG idle rotation speed Nmi to a rotation speed lower than the target idle rotation speed Neii.
• the hybrid control unit 84 sets the MG idle rotation speed Nmi during EV creep running to the target idle rotation speed Neii when the target idle rotation speed Neii of the engine 14 is lower than the predetermined value Nmimx.
• the predetermined value Nmimx is a predetermined upper limit rotation speed of the MG idle rotation speed Nmi during EV creep running (MG idle upper limit rotation speed Nmimx) in consideration of, for example, a balance between the amount of electric power consumed by the electric motor MG during EV creep running and a step in driving force at the time of shifting from EV creep running to engine creep running (that is, on the basis of the amount of electric power consumed by the electric motor MG and a step in driving force).
• the hybrid control unit 84 determines the target idle rotation speed Neii on the basis of the coolant temperature THeng of the engine 14 and the magnitude of the auxiliary load by consulting a predetermined correlation (target idle rotation speed map (not shown)) for determining the target idle rotation speed Neii.
• the target idle rotation speed map is, for example, set such that the target idle rotation speed Neii increases as the coolant temperature THeng decreases or as the magnitude of the auxiliary load increases.
• Traveling state determination means that is, a traveling state determination unit 86, determines whether the target idle rotation speed Neii of the engine 14 is lower than the MG idle upper limit rotation speed Nmimx when the separating clutch K0 is released at the time when creep running is carried out by the hybrid control unit 84.
• FIG. 4 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit 80, that is, control operations for improving fuel economy during EV creep running, and is, for example, repeatedly executed at an extremely short cycle time of about several milliseconds to several tens of milliseconds.
• the flowchart of FIG. 4 is, for example, predicated on a vehicle state where creep running is carried out.
• step 10 corresponding to the traveling state determination unit 86, for example, it is determined whether the separating clutch K0 is released.
• the engine idle rotation speed Nei is set to the target idle rotation speed Neii in S20 corresponding to the hybrid control unit 84.
• S30 corresponding to the hybrid control unit 84. for example, in accordance with the engine idle rotation speed Nei set in S20, the engine 14 is driven through idle rotation speed control (that is, during engine creep running).
• Neii of the engine 14 is higher than or equal to the MG idle upper limit rotation speed Nmimx
• the MG idle rotation speed Nmi during EV creep running is set to the MG idle upper limit rotation speed Nmimx, so, when the target idle rotation speed Neii is set to a value higher than or equal to the MG idle upper limit rotation speed Nmimx, it is possible to suppress an increase in the amount of electric power consumed by the electric motor MG during EV creep running.
• the MG idle rotation speed Nmi during EV creep running is set to the target idle rotation speed Neii, so a step in driving force between during EV creep running and during engine creep running is suppressed as much as possible.
• the MG idle rotation speed Nmi during EV creep running is set to the MG idle upper limit rotation speed Nmimx. Therefore, when the engine 14 is started during EV creep running (that is, when the traveling mode shifts from EV creep running to engine creep running), there is a possibility of occurrence of a step in driving force as the engine idle rotation speed Nei is increased to the target idle rotation speed Neii.
• the MG idle upper limit rotation speed Nmimx is a value that takes a step in driving force into consideration. In this embodiment, a method of further reducing a feeling of strangeness due to the step in driving force is suggested at the time of starting the engine 14.
• the hybrid control unit 84 gradually increases the MG idle rotation speed Nmi toward the target idle rotation speed Neii at a predetermined slope in a period from initiation of the start of the engine 14 to completion of the start of the engine 14 (that is, until engagement of the separating clutch K0 completes).
• the gradual increase in the MG idle rotation speed Nmi may be, for example, carried out immediately after the initiation of the start of the engine 14 or may be carried out when a gradual increase start condition is satisfied after a lapse of a predetermined period of time.
• the MG idle rotation speed Nmi has reached the target idle rotation speed Neii before engagement of the separating clutch K0 completes, the gradual increase is ended at that timing.
• the hybrid control unit 84 sets the engine idle rotation speed Nei after completion of the start of the engine 14 (after completion of engagement of the separating clutch K0) to the MG idle rotation speed Nmi at the engine start completion timing, and, after that, sets the engine idle rotation speed Nei to a value that gradually increases at a predetermined slope from the MG idle rotation speed Nmi at the engine start completion timing toward the target idle rotation speed Neii.
• the gradual increase in the engine idle rotation speed Nei is carried out until the engine idle rotation speed Nei reaches the target idle rotation speed Neii, and, after that, engine creep running is carried out at the target idle rotation speed Neii.
• FIG. 5 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit 80, that is, control operations for improving fuel economy during EV creep running, and is, for example, repeatedly executed at an extremely short cycle time of about several milliseconds to several tens of milliseconds.
• FIG. 6 is a time chart in the case where the control operations shown in the flowchart of FIG. 5 are executed, and is an example at the time of shifting from EV creep running to engine creep running.
• FIG. 5 shows another embodiment corresponding to FIG. 4 in the above-described first embodiment. In FIG. 5, S10 in FIG. 4 is changed to S10', S60 in FIG. 4 is changed to S60', and S20 in FIG. 4 is changed to S20'. The difference from FIG. 4 will be specifically described below.
• separating clutch K0 is being engaged (that is, start control over the engine 14 is being executed) or the separating clutch K0 is released.
• the process proceeds to S40.
• the MG idle rotation speed Nmi is set in S60' corresponding to the hybrid control unit 84.
• S60' for example, it is determined in S601 whether the gradual increase start condition is satisfied (for example, whether a predetermined period of time has elapsed from the initiation of the start of the engine).
• the MG idle rotation speed Nmi is, for example, set to MG idle upper limit rotation speed Nmimx in S602 (tl timing to t2 timing in FIG. 6) until affirmative determination is made in S601.
• the MG idle rotation speed Nmi is, for example, set to a value that gradually increases toward the target idle rotation speed Neii of the engine 14 in S603 (t2 timing to t3 timing in FIG. 6).
• S604 for example, it is determined whether engagement of the separating clutch KO (start of the engine 14) has completed or whether the MG idle rotation speed Nmi is higher than or equal to the target idle rotation speed Neii.
• S603 is repeatedly executed.
• the engine idle rotation speed Nei is set in S20' corresponding to the hybrid control unit 84.
• the engine idle rotation speed Nei is set to the MG idle rotation speed Nmi in S201 (t3 timing in FIG. 6).
• the engine idle rotation speed Nei is set to a value that gradually increases toward the target idle rotation speed Neii in S202 (t3 timing to t4 timing in FIG. 6).
• S203 it is determined whether the engine idle rotation speed Nei is higher than or equal to the target idle rotation speed Neii. Until affirmative determination is made in S203, S202 is repeatedly executed. Through the control shown in FIG. 5, as shown in FIG. 6, the idle rotation speed is continuously controlled at the time of shifting from EV creep running to engine creep running, so the continuity of driving force is maintained.
• the engine idle rotation speed Nei after completion of the start of the engine is set to the MG idle rotation speed Nmi at the timing of completion of engagement of the separating clutch K0, and, after that, is gradually increased to the target idle rotation speed Neii, thus shifting into engine creep running, so driving force is smoothly varied.
• it is possible to improve drivability by suppressing a shock in other words, by reducing a feeling of strangeness experienced by the driver.
• the engine idle rotation speed Nei is not immediately increased to the target idle rotation speed Neii after the start of the engine, and is increased such that the engine idle rotation speed Nei is gradually increased from the MG idle rotation speed Nmi.
• the engine 14 for example, has a predetermined lower limit rotation speed (engine lower limit rotation speed Nemn) at or above which the engine 14 is autonomously operable to keep the engine idle rotation speed Nei in autonomous operation.
• the engine 14 when the engine idle rotation speed Nei that is set after completion of the start of the engine is lower than the engine lower limit rotation speed Nemn, if the engine 14 is controlled so as to generate the power of the engine 14 for keeping the engine idle rotation speed Nei in autonomous operation, it may be difficult to bring the engine idle rotation speed Nei into coincidence with a rotation speed lower than the engine lower limit rotation speed Nemn (that is, the engine idle rotation speed Nei may attempt to become higher than a rotation speed lower than the engine lower limit rotation speed Nemn).
• the hybrid control unit 84 carries out regeneration of the electric motor MG from the power of the engine 14 when the engine idle rotation speed Nei that is set after completion of the start of the engine is lower than the engine lower limit rotation speed Nemn. That is, the hybrid control unit 84 controls the throttle valve opening degree, and the like, so as to keep the engine lower limit rotation speed Nemn, and, in addition to that, carries out regeneration of the electric motor MG (the amount of electric power (negative torque) generated by the electric motor MG is generated) such that the set engine idle rotation speed Nei is attained.
• FIG. 7 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit 80, that is, control operations for improving fuel economy during EV creep running, and is, for example, repeatedly executed at an extremely short cycle time of about several milliseconds to several tens of milliseconds.
• FIG. 8 is a time chart in the case where the control operations shown in the flowchart of FIG. 7 are executed, and is an example at the time of shifting from EV creep running to engine creep running.
• FIG. 7 shows another embodiment corresponding to FIG. 5 in the above-described second embodiment, and FIG. 7 mainly differs from FIG. 5 in the steps of S25 and S28 are further added. The difference from FIG. 5 will be specifically described below.
• the MG idle rotation speed Nmi during EV creep running is set to the MG idle upper limit rotation speed Nmimx. Therefore, when the traveling mode shifts from engine creep running to EV creep running, there is a possibility of occurrence of a step in driving force with a decrease in the MG idle rotation speed Nmi from the target idle rotation speed Neii of the engine 14 to the MG idle upper limit rotation speed Nmimx.
• the MG idle upper limit rotation speed Nmimx is a value that takes a step in driving force into consideration; however, in this embodiment, a method of further reducing a feeling of strangeness due to the step in driving force at the time of stopping the engine 14 is suggested.
• the hybrid control unit 84 sets the MG idle rotation speed Nmi to the target idle rotation speed Neii in a period from initiation of the stop of the engine 14 to at least when the separating clutch K0 is released.
• the hybrid control unit 84 gradually decreases the MG idle rotation speed Nmi from the target idle rotation speed Neii toward the MG idle upper limit rotation speed Nmimx at a predetermined slope.
• the gradual decrease in the MG idle rotation speed Nmi may be, for example, carried out immediately after the separating clutch K0 is released and may be carried out after a gradual decrease start condition is satisfied.
• the gradual decrease start condition is, for example, the fact that a predetermined period of time has elapsed after the separating clutch K0 is released.
• the gradual decrease start condition just needs to be a condition by which it is possible to confirm that the separating clutch K0 is completely released and the engine rotation speed Ne has reliably decreased to a value below the MG idle rotation speed Nmi.
• FIG. 9 is a flowchart that illustrates a relevant portion of control operations of the electronic control unit 80, that is, control operations for improving fuel economy during EV creep running, and is, for example, repeatedly executed at an extremely short cycle time of about several milliseconds to several tens of milliseconds.
• FIG. 10 is a time chart in the case where the control operations shown in the flowchart of FIG. 9 are executed, and is an example at the time of shifting from engine creep running to EV creep running.
• FIG. 9 shows another embodiment corresponding to FIG. 4 in the above-described first embodiment. In FIG. 9, S10 in FIG. 4 is changed to SIO" and S60 in FIG. 4 is changed to S60". The difference from FIG. 4 will be specifically described below.
• S10" corresponding to the traveling state determination unit 86 it is determined whether the separating clutch K0 is being released (that is, stop control over the engine 14 is being executed) or the separating clutch KO is released.
• the process proceeds to S40.
• the MG idle rotation speed Nmi is set in S60" corresponding to the hybrid control unit 84.
• the MG idle rotation speed Nmi is set to the engine idle rotation speed Nei (or the target idle rotation speed Neii) in S605 (tl timing to t3 timing in FIG. 10).
• S606 it is determined whether the gradual decrease start condition is satisfied.
• the process is returned to S605; whereas, when affirmative determination is made in S606, for example, the MG idle rotation speed Nmi is set to a value that gradually decreases toward the MG idle upper limit rotation speed Nmimx in S607 (t3 timing to t4 timing in FIG. 10).
• S608 for example, it is determined whether the MG idle rotation speed Nmi is lower than or equal to the MG idle upper limit rotation speed Nmimx.
• S607 is repeatedly executed. Through the control shown in FIG. 9, as shown in FIG. 10, the idle rotation speed is continuously controlled at the time of shifting from engine creep running to EV creep running, so the continuity of driving force is maintained.
• the MG idle rotation speed Nmi is set to the target idle rotation speed Neii until the separating clutch K0 is released, and, when the engine rotation speed Ne has decreased to a value lower than the MG idle rotation speed Nmi, gradually decreases toward the MG idle upper limit rotation speed Nmimx, so driving force is smoothly varied.
• the engine rotation speed Ne has decreased to a value lower than the MG idle rotation speed Nmi, gradually decreases toward the MG idle upper limit rotation speed Nmimx, so driving force is smoothly varied.
• the above- described fourth embodiment may be implemented in combination with not only the above-described first embodiment but also any one of the above-described second and third embodiments.
• the MG idle rotation speed Nmi is gradually increased after the gradual increase start condition is satisfied; however, the invention is not limited to this embodiment.
• the MG idle rotation speed Nmi may be gradually increased immediately after the initiation of the start of the engine 14.
• S601 and S602 in the flowchart of FIG. 5 in the above-described embodiment may be omitted, the steps, the execution order, and the like, in each of the flowcharts shown in FIG. 4, FIG. 5, FIG. 7, and FIG. 9 may be changed as needed within the range of no difficulty.
• the electric motor MG and the engine 14 are substantially directly coupled to each other. Therefore, a comparison between the MG idle rotation speed Nmi and the target idle rotation speed Neii of the engine 14 directly uses those numeric values; however, the invention is not limited to this embodiment.
• an electric motor rotation speed converted value obtained by converting the MG idle rotation speed Nmi to a rotation speed on the engine shaft (for example, the crankshaft, the engine coupling shaft 32) on the basis of its speed ratio, or the like, is compared with the target idle rotation speed Neii.
• an engine rotation speed converted value obtained by converting the engine rotation speed Ne to a rotation speed on the electric motor shaft, may be compared with the MG rotation speed Nm.
• the word of each rotation speed not only includes each rotation speed itself but also includes each rotation speed converted value.
• the vehicle 10 in which the engine 14 and the electric motor MG are indirectly coupled to each other via the separating clutch K0 is illustrated as the vehicle to which the invention is applied.
• the invention is not limited to this embodiment.
• the invention may also be applied to a vehicle in which no separating clutch K0 is provided and the engine 14 and the electric motor MG are directly coupled to each other.
• the time when the separating clutch K0 is released in each of the above-described embodiments is read as the time when the engine 14 is stopped, and the time when the separating clutch K0 is engaged in each of the above-described embodiments is read as the time when the engine 14 is operated.
• the torque converter 16 is used as the fluid transmission device; instead, another fluid transmission device, such as a fluid coupling having no torque amplification function, may be used.
• the vehicle 10 includes the automatic transmission 18; however, the automatic transmission 18 does not always need to be provided.

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• 2013
  • 2013-04-16 JP JP2013085935A patent/JP2014208502A/ja not_active Withdrawn
• 2014
  • 2014-04-14 WO PCT/IB2014/000639 patent/WO2014170749A1/en active Application Filing

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