WO2008146941A1

WO2008146941A1 - Hybrid vehicle, hybrid vehicle control method, and computer-readable recording medium containing program for causing computer to execute the control method

Info

Publication number: WO2008146941A1
Application number: PCT/JP2008/060119
Authority: WO
Inventors: Hideaki Goda; Kenji Itagaki
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2007-05-29
Filing date: 2008-05-27
Publication date: 2008-12-04
Also published as: JP2008296619A

Abstract

When an EV priority switch is judged to be ON (YES in S10), a travel mode control unit calculates an accelerator open degree based on an accelerator position signal according to a predetermined accelerator pedal operation amount - accelerator open degree nonlinearization map (S20). More specifically, the relationship between the accelerator pedal operation amount and the accelerator open degree is nonlinearized according to the accelerator pedal operation amount - accelerator open degree nonlinearization map so that the accelerator open degree for the same accelerator pedal operation amount is reduced as compared to the one when the EV priority switch is OFF.

Description

TECHNICAL FIELD A control method for a hybrid vehicle, a hybrid vehicle, and a computer-readable recording medium storing a program for causing a computer to execute the control method

The present invention relates to a hybrid vehicle equipped with an internal combustion engine and an electric motor for vehicle travel, a control method for a hybrid vehicle, and a computer-readable recording medium on which a program for causing a computer to execute the control method is recorded.

Background art

Hybrid vehicles (Hybrid Vehicles) are attracting much attention as environmentally friendly vehicles. A hybrid vehicle is a vehicle in which a power storage device, an inverter, and a motor driven by an inverter are mounted as a power source in addition to a conventional engine.

In such a hybrid vehicle, there is known a vehicle that can travel only by a motor without starting an engine (hereinafter, such traveling is referred to as “EV (Electric Vehicle) traveling”). On the other hand, traveling using both the engine and motor is referred to as “HV (Hybrid Vehicle) traveling”. Further, a hybrid vehicle equipped with an EV traveling switch that enables EV traveling by the driver's intention is also known (see, for example, Japanese Patent Application Laid-Open No. 2000-033 3705).

Even when the EV drive switch is turned on in a hybrid vehicle equipped with the EV drive switch as described above, if the driver depresses the accelerator pedal, the engine is started to satisfy the required drive performance, Switch from EV driving to HV driving.

Therefore, if the driver wants to run EV with the EV travel switch turned on: • To maintain EV driving, the driver must operate the accelerator pedal so that it does not step on the accelerator pedal too much. In particular, in vehicles with high driving power, the ratio of the driving power that can maintain EV driving to the driving power that the vehicle can output is Therefore, in order to maintain EV driving when the EV driving switch is on, the driver may be forced to perform subtle accelerator operations. Disclosure of the invention

Therefore, an object of the present invention is to provide a hybrid vehicle that can maintain EV traveling without forcing the driver to perform delicate accelerator operations.

Another object of the present invention is to provide a computer-readable recording method that records a program for causing a computer to execute a control method of a hybrid vehicle that can maintain EV traveling without forcing the driver to perform a delicate accelerator operation, and the control method. It is to provide a possible recording medium.

According to the present invention, the hybrid vehicle includes an internal combustion engine, an electric motor as a power source for traveling the vehicle, a control unit, and an input device. The control unit travels by operating both the internal combustion engine and the electric motor in the first mode (EV mode) in which the internal combustion engine is stopped based on the accelerator opening that changes according to the operation amount of the accelerator pedal. It controls the switching of driving modes including the second mode (HV mode). The input device is provided to restrict the transition from the first mode to the second mode by the control unit based on the operation input of the driver. The control unit shifts from the first mode switch to the second mode when the input device is operated by the driver to restrict the shift from the first mode to the second mode. The relation between the accelerator pedal operation amount and the accelerator opening is changed so that the accelerator opening with respect to the same accelerator pedal operation amount becomes smaller than when the engine is not restricted.

Preferably, when the transition from the first mode to the second mode is restricted, the control unit makes the relationship between the accelerator pedal operation amount and the accelerator opening non-linear according to a predetermined convex function.

More preferably, when the transition from the first mode to the second mode is not restricted, the relationship between the amount of operation of the accelerator pedal and the accelerator opening is linear.

According to the present invention, the control method is a control method for a hybrid vehicle. The hybrid vehicle is equipped with an internal combustion engine and an electric motor as a power source for running the vehicle, and the internal combustion engine is controlled based on the accelerator opening that changes according to the amount of operation of the accelerator pedal. The vehicle can travel in one of the first mode (EV mode) for traveling with the vehicle stopped and the second mode (HV mode) for traveling with both the internal combustion engine and the motor operated. The hybrid vehicle includes an input device for restricting the transition from the first mode to the second mode based on a driver's operation input. The control method includes a step of determining whether or not the transition from the first mode to the second mode is restricted by the operation of the input device by the driver, and from the first mode to the first mode. When it is determined that the transition to the second mode is restricted, the accelerator opening for the same accelerator pedal operation amount than when the transition from the first mode to the second mode is not restricted. And a step of changing a relationship between the amount of operation of the accelerator pedal and the accelerator opening so as to decrease.

Preferably, in the step of changing the relationship between the amount of operation of the accelerator pedal and the accelerator opening, the relationship between the amount of operation of the accelerator pedal and the accelerator opening is made non-linear according to a predetermined convex function.

More preferably, when the transition from the first mode to the second mode is not restricted, the relationship between the operation amount of the accelerator pedal and the accelerator opening is a saddle shape.

Further, according to the present invention, the recording medium is a computer-readable recording medium, and records a program for causing a computer to execute the above-described control method.

In the present invention, the hybrid vehicle can travel in one of the travel modes of the first mode (EV mode) and the second mode (HV mode). Further, it is possible to limit the transition from the first mode to the second mode based on the driver's operation input from the input device. When the input device is operated by the driver and the transition from the first mode to the second mode is restricted, the transition from the first mode to the second mode is restricted. The relationship between the accelerator pedal operation amount and the accelerator opening is changed so that the accelerator opening for the same accelerator pedal operation amount is smaller than when there is no accelerator pedal operation. As a result, the transition from the first mode to the second mode is suppressed. Therefore, according to the present invention, it is possible to maintain EV traveling even when the driver operates the accelerator pedal roughly. As a result, the EV The operability of the pedal is improved.

FIG. 1 is an overall block diagram of a hybrid vehicle according to an embodiment of the present invention.

Fig. 2 is a functional block diagram of ECU shown in Fig. 1.

FIG. 3 is a view showing an example of the accelerator pedal manipulated variable-accelerator opening non-linearization map.

FIG. 4 is a flowchart of accelerator opening calculation processing by the travel mode control unit shown in FIG.

FIG. 5 is a flowchart of the torque command value calculation process by the travel mode control unit shown in FIG.

Fig. 6 is a diagram showing threshold values for switching the driving mode. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is an overall block diagram of a hybrid vehicle according to an embodiment of the present invention. Referring to FIG. 1, hybrid vehicle 100 includes an engine 4, motor generators MG 1 and MG 2, a power split mechanism 3, and wheels 2. The hybrid vehicle 100 includes a power storage device B, a boost converter 10, inverters 20, 30, an ECU (Electronic Control Unit) 50, an EV priority switch 60, a capacitor C 1, C 2, positive lines PL 1 and PL 2, and negative lines NL 1 and NL 2 are further provided.

Power split device 3 is coupled to engine 4 and motor generators MG 1 and MG 2 to distribute power between them. For example, the power split mechanism 3 can be a planetary gear having three rotating shafts: a sun gear, a planetary carrier and a ring gear. These three rotating shafts are connected to the rotating shafts of engine 4 and motor generators MGl and MG2, respectively. For example, motor generator The engine 4 and motor generators MG 1 and MG 2 can be mechanically connected to the power split mechanism 3 by passing the crank shaft of the engine 4 through the center of the MG 1 rotor.

The power generated by the engine 4 is distributed to the wheels 2 and the motor generator MG 1 by the power split mechanism 3. In other words, engine 4 is incorporated into hybrid vehicle 100 as a power source for driving wheel 2 and motor generator MG 1. Motor generator MG 1 operates as a generator driven by engine 4 and is incorporated in hybrid vehicle 10 0 as an electric motor that can start engine 4, and motor generator MG 2 As a power source for driving the wheel 2, it is incorporated into the hybrid vehicle 100. The positive electrode of power storage device B is connected to positive electrode line P L 1, and the negative electrode of power storage device B is connected to negative electrode line N L 1. Capacitor C 1 is connected between positive line P L 1 and negative line N L 1. Boost converter 10 is connected between positive electrode line P L 1 and negative electrode line N L 1 and positive electrode line P L 2 and negative electrode line N L 2. Capacitor C 2 is connected between positive electrode line P L 2 and negative electrode line N L 2. Inverter 20 is connected between positive and negative lines P L 2 and N L 2 and motor generator MG 1. Inverter 30 is connected between positive line P L 2 and negative line N L 2 and motor generator MG 2.

The power storage device で is a DC power source that can be charged and discharged, and is composed of, for example, a secondary battery such as nickel metal hydride ion. Power storage device Β outputs DC power to boost converter 10. In addition, power storage device Β receives power output from boost converter 10 and is charged. A large-capacity capacitor may be used as the power storage device 装置. Capacitor C 1 smoothes the voltage fluctuation between positive line P L 1 and negative line N L 1.

Boost converter 10 boosts the DC voltage output from power storage device 基づい based on signal P WC from ECU 50, and outputs the boosted voltage to positive line PL 2. In addition, boosting converter 10 charges power storage device B by reducing the DC voltage output from inverters 20 and 30 to the voltage level of power storage device B based on signal PWC. The step-up converter 10 is composed of, for example, a step-up / step-down type chitsuba circuit. Capacitor C 2 smoothes voltage fluctuations between positive line PL 2 and negative line NL 2. Inverters 20 and 30 convert DC power supplied from positive electrode line PL 2 and negative electrode line NL 2 into AC power and output it to motor generators MG 1 and MG 2, respectively. Inverters 20 and 30 convert AC power generated by motor generators MG 1 and MG 2 to DC power, respectively, and output them as regenerative power to positive line PL 2 and negative line NL 2.

Each inverter 20 and 30 is composed of a bridge circuit including switching elements for three phases, for example. Inverters 20 and 30 drive corresponding motor generators by performing switching operations in accordance with signals PWI 1 and PWI 2 from ECU 50, respectively.

Motor generators MG 1 and MG2 are three-phase AC motors, for example, three-phase AC synchronous motors. Motor generator MG 1 uses the power of engine 4 to generate three-phase AC power and outputs the generated three-phase AC power to inverter 20. Motor generator MG 1 generates driving force by the three-phase AC power received from inverter 20 and starts engine 4. Motor generator MG 2 generates vehicle driving torque by the three-phase AC power received from inverter 30. Motor generator MG 2 generates three-phase AC power and outputs it to inverter 30 during regenerative braking of the vehicle.

ECU 50 generates signals PWC for driving boost converter 10 and signals PWI 1 and PWI 2 for driving motor generators MG1 and MG2, respectively, and boosts the generated signals PWC, PWI 1 and PWI 2 respectively. Output to comparator 10 and inverters 20 and 30.

Here, according to the method described later, the ECU 50 stops the engine 4 and travels using only the motor generator MG 2 based on the accelerator opening and the vehicle state that change according to the operation amount of the accelerator pedal. (EV mode) or whether to run with engine 4 running (HV mode).

Further, here, the ECU 50 is configured such that when the EV priority switch 60 (described later) is on, the accelerator opening relative to the same accelerator pedal operation amount is reduced even when the EV priority switch 60 is off. , Accelerator pedal operation amount and accelerator Change the relationship with the opening. More specifically, when the EV priority switch 60 is in the OFF state, the relationship between the accelerator pedal operation amount and the accelerator opening is linear, but when the EV priority switch 60 is turned on, the ECU 50 The relationship between the pedal operation amount and the accelerator opening is delinearized according to a pre-defined map.

The EV priority switch 60 is an operation switch for restricting the start of the engine 4 and restricting the transition from the EV mode to the HV mode. When the EV priority switch 6◦ is turned on by the driver, the EV priority switch 60 activates the signal EV output to the ECU 50.

FIG. 2 is a functional block diagram of ECU 50 shown in FIG. Referring to FIG. 2, ECU 50 includes a converter control unit 82, first and second inverter control units 84, 86, and a travel mode control unit 88.

Converter control unit 82 controls voltage VB of power storage device B, voltage VDC between positive line PL 2 and negative line NL 2, motor generators MG 1 and 102, rotation speeds 1 ^ 1 1 ^ 1, MRN2, and travel mode control. Generates a signal PWC for driving boost converter 10 based on torque command values TR 1 and TR 2 of motor generators MG 1 and MG 2 received from section 88, and outputs the generated signal PWC to boost converter 10 To do. The voltages VB and VDC and the rotation speeds MRN 1 and MRN2 are detected by a sensor (not shown).

The first inverter control unit 84 is a signal for driving the motor generator MG 1 based on the voltage VDC, the motor current MCRT 1 of the motor generator MG 1, the rotor rotational position 0 1, and the torque command value TR 1. PWI 1 is generated, and the generated signal PWI 1 is output to the inverter 20. Note that each of the motor current MC RT 1 and the rotor rotational position 01 is detected by a sensor (not shown).

The second inverter control unit 86 drives the motor generator MG 2 based on the voltage VDC, the motor current MCRT 2 of the motor generator MG 2, the rotor rotational position Θ 2, and the torque command value TR 2. The signal PWI 2 is generated, and the generated signal PWI 2 is output to the inverter 30. The motor current MC RT 2 and the rotor rotational position Θ 2 are each measured by a sensor not shown. Detected.

The travel mode control unit 88 includes an accelerator position signal ACC indicating the amount of operation of the accelerator pedal, a vehicle speed signal SPD indicating the vehicle speed, a shift position signal SP indicating the shift position, and a state of charge of the power storage device B (SOC: State Of Charge). It receives the signal EV from the state priority SOC and EV priority switch 60. Then, the travel mode control unit 88 determines whether to operate the engine 4 by the method described later, that is, whether to travel in the EV mode or the HV mode, and based on the determination result, the torque command value TR 1 and TR 2 are generated and output to the converter control unit 82 and the first and second inverter control units 84 and 86.

Here, when the signal EV from the EV priority switch 60 is activated, the traveling mode control unit 88 determines that the accelerator position signal AC C according to the accelerator pedal operation amount-accelerator opening non-linearization map defined in advance. Calculate the accelerator opening based on. The travel mode control unit 88 calculates an engine output request value based on the calculated accelerator opening, vehicle speed signal SPD, shift position signal SP, and state quantity SOC, and calculates the engine output. The driving mode is determined depending on whether the required value exceeds a predetermined threshold.

The operation amount of the accelerator pedal is detected by an accelerator position sensor (not shown). Further, the vehicle speed and the shift position are detected by a vehicle speed sensor and a shift position sensor (not shown), respectively.

FIG. 3 is a diagram showing an example of an accelerator pedal operation amount vs. an accelerator opening degree non-linearization map. Referring to FIG. 3, a straight line k 1 indicated by a dotted line shows the relationship between the accelerator pedal operation amount and the accelerator opening when the EV priority switch 60 is in the OFF state. In other words, when the EV priority switch 60 is in the OFF state, the relationship between the accelerator pedal operation amount and the accelerator opening is linear.

A curve k2 indicated by a solid line shows the relationship between the amount of operation of the accelerator pedal and the accelerator opening when the EV priority switch 60 is in the on state. When the EV priority switch 60 is in the ON state, the relationship between the accelerator pedal operation amount and the accelerator opening is made non-linear according to the curve k2. More specifically, even when the EV priority switch 60 is in the OFF state, the convexity is reduced so that the accelerator opening with respect to the same accelerator pedal operation amount becomes smaller. The relationship between the accelerator pedal operation amount and the accelerator opening is nonlinearized according to the curve k 2 consisting of numbers.

As a result, even if the accelerator pedal is operated roughly, the required engine output value is suppressed by suppressing the accelerator opening relative to the accelerator pedal operation amount, and as a result, the transition from EV mode to HV mode is suppressed. Is done. In other words, EV driving can be maintained even if the accelerator pedal is operated roughly, and the operability of the accelerator pedal is improved.

It should be noted that the relationship between the accelerator pedal operation amount and the accelerator opening when the EV priority switch 60 is on is a convex function as indicated by the curve k2, because the accelerator pedal operation amount is normally This is to increase the amount of change in the accelerator opening from the straight line k1 in the operation range (medium). That is, in order to obtain the maximum effect of improving the operability of the accelerator pedal in the normal operation range (medium).

FIG. 4 is a flowchart of accelerator opening degree calculation processing by the travel mode control unit 88 shown in FIG. It should be noted that the processing of this flowchart is called from the main routine and executed every certain time or when a predetermined condition is satisfied when the vehicle is ready to travel (for example, when the vehicle system is being activated). .

Referring to FIG. 4, traveling mode control unit 8 8 determines whether or not EV priority switch 60 is on based on signal EV from EV priority switch 60 (step S 1 0 ) If it is determined that EV priority switch 6 is off (NO in step S 10), traveling mode control unit 88 performs processing to the main routine without executing the subsequent series of processing. return.

If it is determined in step S 10 that the EV priority switch 60 is on (YES in step S 10), the travel mode control unit 8 8 makes the accelerator pedal operation amount one accelerator opening non-linearization described above. Using the map (curve k 2), the accelerator opening is calculated based on the accelerator position signal ACC (step S 2 0). Then, traveling mode control unit 88 actually performs the accelerator opening changing process (step S 30). Specifically, when the accelerator opening is suddenly changed when the EV priority switch 60 is turned on, the engine output request value changes rapidly. Therefore, the travel mode control unit 8 8 determines that the accelerator pedal operation amount is equal to the accelerator opening non-linearization map (curve k 2) from the accelerator opening according to the straight line k 1 shown in FIG. ) Limit the change rate when changing to the accelerator opening according to.

Next, the traveling mode control unit 88 determines whether or not the EV priority switch 60 is off based on the signal EV from the EV priority switch 60 (step S 40). If it is determined that EV priority switch 60 is off (YES in step S 40), travel mode control unit 88 actually performs the accelerator opening return process (step S 5 0). Specifically, if the accelerator opening is suddenly returned at the timing when the EV priority switch 60 is turned off, the engine output request value may change abruptly, which may adversely affect the running of the vehicle. Therefore, the travel mode control unit 8 8 returns from the accelerator opening according to the accelerator pedal operation amount to the accelerator opening non-linearization map (curve k 2) shown in FIG. 3 to the accelerator opening according to the straight line k 1. Limit the rate of change.

If it is determined in step S10 that the EV priority switch 60 is in the OFF state, the accelerator pedal opening is not changed to the accelerator opening according to the accelerator pedal operation amount minus the accelerator opening non-linearization map. The accelerator opening is determined based on the accelerator position signal ACC according to the prescribed linear relationship indicated by the straight line k 1 shown. FIG. 5 is a flowchart of a torque command value calculation process by the travel mode control unit 88 shown in FIG. The process of this flowchart is also called and executed from the main routine every certain time or when a predetermined condition is satisfied when the vehicle is ready to travel (for example, when the vehicle system is starting up). .

Referring to FIG. 5, traveling mode control unit 8 8 includes accelerator position calculated based on accelerator position signal ACC according to the flowchart shown in FIG. 4, and vehicle speed signal SPD and shift position signal SP. Based on the above, the required drive torque (axle) of the vehicle is calculated using a preset map or calculation formula (step S 1 1 0). Then, traveling mode control unit 88 calculates a drive request output of the vehicle based on the calculated drive request torque and axle rotation speed (step S 1 2 0). Specifically, the required drive output is obtained by multiplying the required drive torque by the axle speed. Calculated.

Next, traveling mode control unit 88 calculates an engine output request value based on the calculated drive request output and SOC of power storage device B (step S130). Specifically, the required charge amount of power storage device B is calculated based on the SOC of power storage device B, and the required engine output value is calculated by adding the required charge amount to the drive request output.

Next, traveling mode control unit 88 determines whether or not EV priority switch 60 is in the ON state based on signal EV from EV priority switch 60 (step S140). If it is determined that EV priority switch 60 is in the ON state (YES in step S 140), traveling mode control unit 88 corrects the threshold value for determining whether to switch the traveling mode (step S). 150). This threshold value is a value for determining whether or not the engine 4 needs to be started, in other words, a threshold value for switching the running mode.

Fig. 6 is a diagram showing threshold values for switching the driving mode. Referring to Fig. 6, the vertical axis represents the required engine output value, and the horizontal axis represents the vehicle speed. A threshold value k 3 indicated by a solid line indicates a switching threshold value when the EV priority switch 60 is in the OFF state. When the engine output request value is less than or equal to the threshold k3, it is determined that the engine 4 is stopped and the vehicle is traveling (EV mode). It is determined that the vehicle will start and run (HV mode). This threshold value k 3 changes according to the vehicle speed, for example, it is large at low speed (ie, emphasizing EV mode), and becomes 0 when the vehicle speed exceeds the specified ffi! SPDO (ie, Always in HV mode).

A threshold value k 4 indicated by a dotted line indicates a switching threshold value when the EV priority switch 60 is in an ON state. That is, when the EV priority switch 60 is in the ON state, the travel mode switching threshold value is corrected so that the travel range in the EV mode is expanded.

Referring again to FIG. 5, traveling mode control unit 88 determines whether or not the engine output request value calculated in step S 1 30 is larger than the traveling mode switching threshold value (step S 160). . The engine output request value is determined to be below the threshold value. If determined (NO in step S160), the process proceeds to step S190 described later.

On the other hand, when it is determined that the required engine output value is larger than the threshold value (YES in step S 160), traveling mode control unit 88 calculates target speed of engine 4 and actually controls engine 4. Execute (Step S170). Then, traveling mode control unit 88 calculates target rotational speed of motor generator MG 1 for maintaining engine 4 at the target rotational speed, and torque command value TR 1 for controlling motor generator MG 1 to the target rotational speed. Is calculated (step S 180).

Next, traveling mode control unit 88 calculates the generated torque (engine direct torque) of engine 4 from torque command value TR 1 of motor generator MG 1 (step S 1 90). The engine direct torque can be calculated from the torque command value TR 1 based on the geometric configuration (number of teeth ratio) of the power split mechanism 3. When the engine output request value is less than or equal to the threshold value, the engine 4 stops and the engine direct torque becomes zero. When the engine direct torque is calculated, the traveling mode control unit 88 subtracts the engine direct torque from the drive request torque calculated in step S 1 10, so that the motor generator MG 2 torque command is issued. The value TR 2 is calculated (step S 200).

As described above, in this embodiment, hybrid vehicle 100 can travel in either the EV mode or the HV mode. In addition, the transition from EV mode to HV mode can be restricted based on the driver's operation input from EV priority switch 60. When the EV priority switch 60 is in the ON state, the relationship between the accelerator pedal operation amount and the accelerator opening is changed according to the accelerator pedal operation amount vs. the accelerator opening non-linearization map, so that the accelerator opening used for control is suppressed. As a result, the required engine output value is suppressed, and as a result, the transition from EV mode to HV mode is suppressed. Therefore, according to this embodiment, it is possible to maintain EV traveling even when the driver operates the accelerator pedal roughly. As a result, the operability of the acceleration pedal during EV driving is improved.

In addition, since the relationship between the accelerator pedal operation amount and the accelerator opening when the EV priority switch 60 is on is a convex function as shown by the curve k2, the accelerator pedal In the normal operation range (medium), the amount of change in the accelerator opening from when the EV priority switch 60 is off is large. Therefore, the effect of improving the operability of the accelerator pedal can be maximized when the amount of operation of the accelerator pedal is normal (medium).

In the above embodiment, the relationship between the accelerator pedal operation amount and the accelerator opening when the EV priority switch 60 is in the ON state is in accordance with a predetermined accelerator pedal operation amount-accelerator opening non-linearization map. Although it was assumed, an arithmetic expression may be used instead of the map.

In the above description, the threshold value for switching from EV mode to HV mode and the threshold value for switching from HV mode to EV mode are the same. However, these threshold values are different. It is also possible to provide a hysteresis for switching the driving mode.

Further, in the above, the hybrid vehicle is a series Z parallel type in which the power of the engine 4 can be divided and transmitted to the axle and the motor generator MG 1 by the power split mechanism 3, but the present invention is a motor generator MG 1 The engine 4 is used only to drive the vehicle, and the electric power generated by the motor generator MG 1 is used. The present invention can also be applied to a series type hybrid vehicle that generates the driving force of the vehicle only by the motor generator MG 2.

In the above, the control in E C U 50 is actually C P U

(Central Processing Unit), the CPU reads a program including each step of the flowcharts shown in FIGS. 4 and 5 from a ROM (Read Only Memory), and executes the read program to execute FIGS. The process is executed according to the flowchart shown in. Therefore, the ROM corresponds to a computer (CPU) readable recording medium in which a program including the steps of the flowcharts shown in FIGS. 4 and 5 is recorded.

In the above, engine 4 corresponds to an embodiment of “internal combustion engine” in the present invention, and motor generator MG 2 corresponds to an embodiment of “electric motor” in the present invention. Further, the travel mode control unit 88 of the ECU 50 corresponds to one embodiment of the “control unit” in the present invention, and the EV priority switch 60 corresponds to one embodiment of the “input device” in the present invention. Correspond. It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims, and is intended to include meanings equivalent to the scope of claims and all modifications within the scope.

Claims

The scope of the claims

1. Internal combustion engine (4),

An electric motor (MG2) as a power source for vehicle travel;

The first mode (EV mode), the internal combustion engine (4), and the electric motor (MG 2) are operated by stopping the internal combustion engine (4) on the basis of the accelerator opening that changes according to the amount of operation of the accelerator pedal. A control unit (88) that controls switching of a travel mode including a second mode (HV mode) that travels by operating both of the above and the control unit (88) based on the operation input of the driver An input device (60) for restricting the transition from the first mode (EV mode) to the second mode (HV mode),

The control unit (88) is restricted from shifting from the first mode (EV mode) to the second mode (HV mode) by operating the input device (60) by a driver. The accelerator opening for the same accelerator pedal operation amount is smaller than when the transition from the first mode (EV mode) to the second mode (HV mode) is not restricted. A hybrid vehicle that changes the relationship between the accelerator pedal operation amount and the accelerator opening.

2. When the transition from the first mode (EV mode) to the second mode (HV mode) is restricted, the control unit (88) operates the accelerator pedal operation amount and the accelerator opening degree. The hybrid vehicle according to claim 1, wherein the relationship is made non-linear according to a predetermined convex function.

3. When the transition from the first mode (EV mode) to the second mode (HV mode) is not restricted, the relationship between the manipulated variable of the accelerator pedal and the accelerator opening is linear. The hybrid vehicle according to claim 2.

4. An internal combustion engine (4) and an electric motor (MG2) as a power source for vehicle travel are mounted, and the internal combustion engine (4) is controlled based on the accelerator opening that changes according to the operation amount of the accelerator pedal. Traveling in one of the travel modes of the first mode (EV mode) in which the vehicle is stopped and the second mode (HV mode) in which both the internal combustion engine (4) and the electric motor (MG2) are operated Possible hybrid vehicle (1 0 0) control method,

The hybrid vehicle (100) has an input device for restricting a transition from the first mode (EV mode) to the second mode (HV mode) based on a driver's operation input. 6 0)

The control method is:

It is determined whether or not the transition from the first mode (EV mode) to the second mode (HV mode) is restricted by the driver operating the input device (60). Steps,

When it is determined that the transition from the first mode (EV mode) to the second mode (HV mode) is restricted, the second mode is changed from the first mode (EV mode) to the second mode. The step of changing the relationship between the accelerator pedal operation amount and the accelerator opening so that the accelerator opening with respect to the same accelerator pedal operation amount becomes smaller than when the transition to the (HV mode) is not restricted. A method for controlling a hybrid vehicle, including:

5. In a step of changing the relationship between the amount of operation of the accelerator pedal and the opening degree of the accelerator pedal, the relationship between the amount of operation of the accelerator pedal and the opening degree of the accelerator is made non-linear according to a predetermined convex function. The control method of a hybrid vehicle according to 4 of the above.

6. When the transition from the first mode (EV mode) to the second mode (HV mode) is not restricted, the relationship between the operation amount of the accelerator pedal and the accelerator opening is linear. The hybrid vehicle control method according to claim 5.

7. A computer-readable recording medium storing a program for causing a computer to execute the hybrid vehicle control method according to any one of claims 4 to 6.