JP2012144175A - Vehicle and its controlling method - Google Patents

Abstract

In a vehicle configured to allow a driver to select either a normal mode or a power mode, the generation of a driving force not intended by the driver is suppressed.
A vehicle is configured to allow a driver to select either a first travel mode or a second travel mode in which the vehicle driving force for the same accelerator operation amount is larger than the first travel mode. . The vehicle increases the vehicle driving force as compared with that in the first traveling mode when detecting the switching request to the second traveling mode from the driver and the detecting means for detecting the switching request. Accordingly, a switching means for switching the vehicle to the second traveling mode, a lock detecting means for detecting the lock state of the wheel when a switching request is detected, and a lock state of the wheel is detected. And prohibiting means for prohibiting switching to the second travel mode by the switching means.
[Selection] Figure 4

Description

  The present invention relates to a vehicle and a control method thereof, and more specifically, to a vehicle having a normal mode and a power mode in which a vehicle driving force with respect to the same accelerator operation amount is larger than that of the normal mode, and a control method thereof.

  As this type of vehicle, for example, Japanese Patent Application Laid-Open No. 2007-91073 (Patent Document 1) has either a normal mode corresponding to normal travel or a power mode in which a driving force larger than the normal mode is obtained. A hybrid vehicle configured to be selectable by a driver is disclosed.

  In the hybrid vehicle described in Patent Document 1, when the operation of the power switch for selecting the power mode is detected while the vehicle is traveling in the normal mode, the accelerator pedal is further depressed thereafter. After waiting, the driving mode is switched from the normal mode to the power mode. As a result, even when an abnormality occurs in the power switch for some reason, the vehicle is prevented from traveling with an unexpectedly large driving force.

JP 2007-91073 A JP 2007-69625 A JP 2008-163867 A

  However, according to the hybrid vehicle described in Patent Document 1, when switching of the operation of the power switch is detected, the vehicle is switched to the power mode according to the depression of the accelerator pedal. In a scene where the wheel is locked, the traveling mode is switched to the power mode when the driver depresses the accelerator pedal to cause the wheel to escape from the locked state. For this reason, there is a problem in that a driving force unintended by the driver is output in spite of a traveling situation in which the driver needs to finely adjust the accelerator opening.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to drive the driver unintentionally in a vehicle configured so that the driver can select either the normal mode or the power mode. It is to suppress the generation of force.

  In one aspect of the present invention, the vehicle includes a first travel mode and a second travel mode in which the vehicle driving force with respect to the same accelerator operation amount is greater than that in the first travel mode. The vehicle increases the vehicle driving force as compared with that in the first traveling mode when detecting the switching request to the second traveling mode from the driver and the detecting means for detecting the switching request. Accordingly, a switching means for switching the vehicle to the second traveling mode, a lock detecting means for detecting the lock state of the wheel when a switching request is detected, and a lock state of the wheel is detected. And prohibiting means for prohibiting switching to the second travel mode by the switching means.

  Preferably, the vehicle includes a lock escape detecting means for detecting that the wheel has escaped from the locked state during a period in which switching to the second travel mode is prohibited by the prohibiting means, and a driver's accelerator operation An accelerator operation detecting means for detecting the amount is further provided. The prohibiting means permits switching to the second traveling mode by the switching means when it is detected that the wheel has escaped from the locked state. When switching to the second traveling mode is permitted by the prohibiting means, the switching means uses the first vehicle driving force set based on the accelerator operation amount detected in the first traveling mode, The vehicle driving force is gradually increased up to the second vehicle driving force set based on the accelerator operation amount detected in the travel mode.

  Preferably, the vehicle further includes an electric motor mechanically coupled to a drive shaft for driving the wheels. The lock detection means detects the locked state of the wheel when the vehicle speed is equal to or lower than a predetermined threshold value and the electric motor is locked.

  In another aspect of the present invention, there is provided a vehicle control method including a first travel mode and a second travel mode in which the vehicle driving force with respect to the same accelerator operation amount is larger than the first travel mode. A step for detecting the switching request to the second traveling mode, and when the switching request is detected by the detecting step, by increasing the vehicle driving force as compared with the first traveling mode, When the switching request is detected by the step for switching the vehicle to the second traveling mode and the detecting step, the step for detecting the locked state of the wheel and the detecting step detect the locked state of the wheel. And a step for prohibiting switching to the second traveling mode by the switching step.

  According to the present invention, in a vehicle configured so that the driver can select either the normal mode or the power mode, it is possible to suppress the generation of a driving force not intended by the driver.

1 is a schematic configuration diagram of a hybrid vehicle shown as a representative example of a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining details of a power train in the hybrid vehicle of FIG. 1. It is a block diagram which shows the control structure in ECU according to this Embodiment. It is a flowchart which shows the driving mode switching operation | movement in ECU. 6 is a flowchart for explaining a subroutine of step S08 (travel mode switching process) in FIG. It is a figure which shows an example of the map for execution accelerator opening setting. It is a figure which shows an example of the map for request | requirement torque setting.

  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 description thereof will not be repeated.

(Vehicle configuration)
FIG. 1 is a schematic configuration diagram of a hybrid vehicle 5 shown as a representative example of a vehicle according to an embodiment of the present invention.

  Referring to FIG. 1, hybrid vehicle 5 includes an engine ENG, motor generators MG1 and MG2, a battery 10, a power conversion unit (PCU: Power Control Unit) 20, a power split mechanism PSD, a reduction gear RD, Front wheels 70L and 70R, rear wheels 80L and 80R, and an electronic control unit (ECU) 30 are provided. The control device according to the present embodiment is realized, for example, by a program executed by ECU 30. 1 illustrates the hybrid vehicle 5 using the front wheels 70L and 70R as drive wheels, the rear wheels 80L and 80R may be used as drive wheels instead of the front wheels 70L and 70R. Alternatively, in addition to the configuration shown in FIG. 1, a motor generator for driving the rear wheels 80L and 80R may be further provided to provide a 4WD configuration.

  The driving force generated by the engine ENG is divided into two paths by the power split mechanism PSD. One is a path for driving the front wheels 70L and 70R via the reduction gear RD. The other is a path for generating electric power by driving the motor generator MG1.

  Motor generator MG1 is typically constituted by a three-phase AC synchronous motor generator. Motor generator MG1 generates electricity as a generator by the driving force of engine ENG divided by power split mechanism PSD. Motor generator MG1 has not only a function as a generator but also a function as an actuator for controlling the rotational speed of engine ENG.

  The electric power generated by motor generator MG1 is selectively used according to the driving state of the vehicle and the state of charge (SOC) of battery 10. For example, during normal running or sudden acceleration, the electric power generated by motor generator MG1 is used as power for driving motor generator MG2 as a motor. On the other hand, when the SOC of battery 10 is lower than a predetermined value, the power generated by motor generator MG1 is converted from AC power to DC power by power conversion unit 20 and stored in battery 10.

  The motor generator MG1 is also used as a starter when starting the engine ENG. When starting engine ENG, motor generator MG1 is supplied with electric power from battery 10 and is driven as an electric motor. Then, motor generator MG1 cranks engine ENG and starts it.

  Motor generator MG2 is typically constituted by a three-phase AC synchronous motor generator. When motor generator MG2 is driven as an electric motor, it is driven by at least one of electric power stored in battery 10 and electric power generated by motor generator MG1. The driving force of motor generator MG2 is transmitted to front wheels 70L and 70R via reduction gear RD. Thus, motor generator MG2 assists engine ENG to travel the vehicle or causes the vehicle to travel only by the driving force of motor generator MG2.

  During regenerative braking of the vehicle, the motor generator MG2 is driven by the front wheels 70L and 70R via the reduction gear RD, and the motor generator MG2 is operated as a generator. Thus, motor generator MG2 acts as a regenerative brake that converts braking energy into electric energy. The electric power generated by motor generator MG2 is stored in battery 10 via power conversion unit 20.

  The battery 10 is constituted by a secondary battery such as nickel hydride or lithium ion, for example. In the embodiment of the present invention, battery 10 is shown as a representative example of “power storage device”. That is, another power storage device such as an electric double layer capacitor can be used in place of the battery 10. The battery 10 supplies a DC voltage to the power conversion unit 20 and is charged by the DC voltage from the power conversion unit 20.

  The power conversion unit 20 performs bidirectional power conversion between DC power supplied by the battery 10, AC power for driving and controlling the motor, and AC power generated by the generator.

  The hybrid vehicle 5 further includes a steering wheel 40, an accelerator position sensor 44 that detects an accelerator opening Acc corresponding to the amount of depression of the accelerator pedal by the driver, a brake pedal position sensor 46 that detects a brake pedal position BP, and a shift. And a shift position sensor 48 for detecting the position SP.

  Motor generators MG1 and MG2 are further provided with rotation angle sensors 51 and 52 for detecting the rotor rotation angle. Rotor rotation angle θ1 of motor generator MG1 detected by rotation angle sensor 51 and rotor rotation angle θ2 of motor generator MG2 detected by rotation angle sensor 52 are transmitted to ECU 30. The rotation angle sensors 51 and 52 estimate the rotor rotation angle θ1 from the current, voltage and the like of the motor generator MG1 in the ECU 30, and estimate the rotor rotation angle θ2 from the current, voltage and the like of the motor generator MG2. The arrangement may be omitted.

  The hybrid vehicle 5 further includes a power switch 90. The power switch 90 is a switch for the driver to select traveling in a power mode that emphasizes acceleration. The power switch 90 is electrically connected to the ECU 30. The ECU 30 receives a power switch signal Psw indicating the on / off state of the power switch 90. When the power switch signal Psw is on, the ECU 30 determines that the power mode is selected by the driver.

  ECU 30 is electrically connected to engine ENG, power conversion unit 20 and battery 10. Based on the detection signals from the various sensors and the power switch signal Psw from the power switch 90, the ECU 30 drives the engine ENG and the motor generators MG1 and MG2 so that the hybrid vehicle 5 enters a desired running state. The state and the charge state of the battery 10 are controlled in an integrated manner.

  FIG. 2 is a schematic diagram for explaining details of the power train in the hybrid vehicle 5 of FIG. 1.

  Referring to FIG. 2, the power train (hybrid system) of hybrid vehicle 5 includes motor generator MG2, reduction gear RD connected to output shaft 160 of motor generator MG2, engine ENG, motor generator MG1, A splitting mechanism PSD.

  In the example shown in FIG. 2, the power split mechanism PSD is constituted by a planetary gear mechanism, and a sun gear 151 coupled to a hollow sun gear shaft penetrating the crankshaft 150 through the center of the shaft, and rotates coaxially with the crankshaft 150. The ring gear 152 that is supported, the pinion gear 153 that is disposed between the sun gear 151 and the ring gear 152 and revolves around the outer periphery of the sun gear 151, and the rotation of each pinion gear 153 coupled to the end of the crankshaft 150. And a planetary carrier 154 that supports the shaft.

  In power split mechanism PSD, three axes of a sun gear shaft coupled to sun gear 151, a ring gear case 155 coupled to ring gear 152, and crankshaft 150 coupled to planetary carrier 154 serve as power input / output shafts. When the power input / output to / from any two of the three axes is determined, the power input / output to the remaining one axis is determined based on the power input / output to the other two axes.

  A counter drive gear 170 for extracting power is provided outside the ring gear case 155 and rotates integrally with the ring gear 152. Counter drive gear 170 is connected to power transmission reduction gear RG. The ring gear case 155 corresponds to the “output member” in the present invention. In this way, power split device PSD operates to output at least a part of the output from engine ENG to the output member with the input and output of electric power and power by motor generator MG1.

  Further, power is transmitted between the counter drive gear 170 and the power transmission reduction gear RG. The power transmission reduction gear RG drives a differential gear DEF coupled to the front wheels 70L and 70R that are drive wheels. On the downhill or the like, the rotation of the driving wheel is transmitted to the differential gear DEF, and the power transmission reduction gear RG is driven by the differential gear DEF.

  Motor generator MG1 includes a stator 131 that forms a rotating magnetic field, and a rotor 132 that is disposed inside stator 131 and has a plurality of permanent magnets embedded therein. Stator 131 includes a stator core 133 and a three-phase coil 134 wound around stator core 133. Rotor 132 is coupled to a sun gear shaft that rotates integrally with sun gear 151 of power split device PSD. The stator core 133 is formed by laminating thin electromagnetic steel plates, and is fixed to a case (not shown).

  Motor generator MG1 operates as an electric motor that rotationally drives rotor 132 by the interaction between the magnetic field generated by the permanent magnet embedded in rotor 132 and the magnetic field formed by three-phase coil 134. Motor generator MG1 also operates as a generator that generates electromotive force at both ends of three-phase coil 134 due to the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 132.

  Motor generator MG2 includes a stator 136 that forms a rotating magnetic field, and a rotor 137 that is disposed inside stator 136 and has a plurality of permanent magnets embedded therein. Stator 136 includes a stator core 138 and a three-phase coil 139 wound around stator core 138.

  The rotor 137 is coupled to a ring gear case 155 that rotates integrally with the ring gear 152 of the power split mechanism PSD via a reduction gear RD. Stator core 138 is formed, for example, by laminating thin magnetic steel sheets, and is fixed to a case (not shown).

  Motor generator MG2 also operates as a generator that generates an electromotive force at both ends of three-phase coil 139 by the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 137. Motor generator MG2 operates as an electric motor that rotates rotor 137 by the interaction between the magnetic field generated by the permanent magnet and the magnetic field formed by three-phase coil 139.

  The speed reducer RD performs speed reduction by a structure in which a planetary carrier 166 that is one of rotating elements of a planetary gear is fixed to a case. That is, reduction device RD meshes with sun gear 162 coupled to output shaft 160 of rotor 137, ring gear 168 that rotates integrally with ring gear 152, ring gear 168 and sun gear 162, and transmits the rotation of sun gear 162 to ring gear 168. Pinion gear 164. For example, by reducing the number of teeth of the ring gear 168 to more than twice the number of teeth of the sun gear 162, the reduction ratio can be increased more than twice.

  Thus, the rotational force of motor generator MG2 is transmitted to output member (ring gear case) 155 that rotates integrally with ring gears 152 and 168 via reduction gear RD. That is, motor generator MG2 is configured to apply power between output member 155 and the drive wheel. Note that the arrangement of the reduction gear RD may be omitted, that is, the output shaft 160 of the motor generator MG2 and the output member 155 may be connected without providing a reduction ratio.

  Power conversion unit 20 includes a converter 12 and inverters 14 and 22. Converter 12 converts DC voltage Vb from battery 10 and outputs DC voltage VH between power supply line PL and ground line GL. Converter 12 is configured to be capable of voltage conversion in both directions, and converts DC voltage VH between power supply line PL and ground line GL into charging voltage Vb of battery 10.

  Inverters 14 and 22 are constituted by general three-phase inverters, convert DC voltage VH between power supply line PL and ground line GL into an AC voltage, and output the AC voltage to motor generators MG2 and MG1, respectively. Inverters 14 and 22 convert the AC voltage generated by motor generators MG2 and MG1 into DC voltage VH and output the voltage between power supply line PL and ground line GL.

  The hybrid vehicle 5 configured as described above is configured to be able to travel by selecting a normal mode corresponding to normal traveling and a power mode in which the vehicle driving force with respect to the same accelerator operation amount is larger than the normal mode. The driver can select either the normal mode or the power mode by operating the power switch 90. As will be described later, the ECU 30 stores a table in which the selected travel mode and the required torque to be output to the output member 155 are associated with each other. The required torque stored in this table is set so that the driving force obtained for a predetermined accelerator opening is higher in the power mode than in the normal mode. The ECU 30 calculates a required torque to be output to the output member 155 based on the accelerator opening Acc with reference to this table in each travel mode. Then, the operating state of engine ENG and the driving states of motor generators MG1, MG2 are controlled so that the required driving force corresponding to this required torque is output to output member 155.

(Control structure)
Next, referring to FIG. 3, a control structure for realizing the operation of switching the travel mode of the vehicle according to the present embodiment will be described with reference to the drawings.

  FIG. 3 is a block diagram showing a control structure in ECU 30 according to the present embodiment. Each function block shown in FIG. 3 is typically realized by the ECU 30 executing a program stored in advance, but a part or all of the function may be implemented as dedicated hardware.

  Referring to FIG. 3, ECU 30 includes MG2 lock detection unit 300, travel mode selection unit 310, charge / discharge control unit 320, travel control unit 330, distribution unit 340, inverter control unit 350, and converter control. Part 360.

  MG2 lock detection unit 300 detects MG2 rotation speed Nm2 based on rotor rotation angle θ2 detected or estimated by rotation speed sensor 51 of motor generator MG2. Then, MG2 lock detection unit 300 detects whether or not motor generator MG2 is locked based on detected MG2 rotation speed Nm2 and current of motor generator MG2. When the lock state occurs, the MG2 lock detection unit 300 sets the lock determination flag FLC to ON.

  The lock detection by the MG2 lock detection unit 300 indicates that the MG2 rotational speed Nm2 is in an extremely low rotational speed region (N2n ≦ Nm2 ≦ N2p) including the rotational speed = 0, and the current of the motor generator MG2 is a predetermined value. The determination is made based on whether or not the lock determination value M2 or more. N2p is a lock determination value for the normal rotation area and N2n is a lock determination value for the reverse rotation area. M2 is set to have a current value higher than the three-phase current of motor generator MG2, taking into account that the current continuously flows in a specific phase of motor generator MG2 when the locked state occurs.

  Lock detection may be performed based on the MG2 rotation speed and the torque command value of motor generator MG2. In this case, it can be determined that the motor generator MG2 is locked when the MG2 rotation speed does not increase despite the torque command value being given to the motor generator MG1.

  Traveling mode selection unit 310 receives lock determination flag FLC from MG2 lock detection unit 300, receives power switch signal Psw from power switch 90, and receives vehicle speed V from vehicle speed sensor 100. Traveling mode selection unit 310 selects one of the normal mode and the power mode based on these input signals. Traveling mode selection unit 310 generates a traveling mode flag FM indicating which of the normal mode and the power mode is selected. The travel mode flag FM is sent to the travel control unit 330.

  Charging / discharging control unit 320 sets charging power upper limit value Win and discharging power upper limit value Wout based on the SOC of battery 10. Although not shown, the SOC of the battery 10 is an estimated SOC value calculated based on battery data (current, voltage, and temperature of the battery 10) from a battery monitoring unit provided in the battery 10.

  The traveling control unit 330 calculates a vehicle driving force and a vehicle braking force necessary for the entire hybrid vehicle 5 according to the traveling mode, vehicle state, and driver operation of the hybrid vehicle 5. The vehicle state includes a vehicle speed V. The driver operation includes an accelerator opening Acc, a brake pedal position BP, a shift position SP, and the like.

  Travel control unit 330 determines an output request to motor generators MG1 and MG2 and an output request to engine ENG so as to realize the requested vehicle driving force or vehicle braking force. Hybrid vehicle 5 can travel only with the output of motor generator MG2 while engine ENG is stopped. Therefore, energy efficiency can be improved by determining each output request so as to operate the engine ENG while avoiding a region where the fuel efficiency is poor. Furthermore, the output request to motor generators MG1 and MG2 is set after limiting the charging and discharging of battery 10 within the power range (Win to Wout) in which battery 10 can be charged and discharged. That is, when the output power of battery 10 cannot be secured, the output from motor generator MG2 is limited.

  Distribution unit 340 calculates the torque and rotation speed of motor generators MG1 and MG2 in response to the output request to motor generators MG1 and MG2 set by travel control unit 330. Then, a control command for torque and rotation speed is output to inverter control unit 350, and at the same time, a control command value for voltage VH is output to converter control unit 360.

  On the other hand, the distribution unit 340 generates an engine control instruction indicating the engine power and the engine target rotation speed determined by the travel control unit 330. In accordance with this engine control instruction, fuel injection, ignition timing, valve timing, etc. of an engine ENG (not shown) are controlled.

  Inverter control unit 350, in response to a control command from distribution unit 340, a control signal for giving a drive instruction to convert a DC voltage, which is the output of converter 12, into an AC voltage for driving motor generator MG1, and a motor generator A control signal for generating a regeneration instruction for converting the AC voltage generated by MG1 into a DC voltage and returning it to the converter 12 side is generated. These motor generator MG1 control commands (MG1 control commands) are output to inverter 22. Similarly, inverter control unit 350 converts the AC signal generated by motor generator MG2 into a DC voltage and a control signal for instructing driving to convert DC voltage into AC voltage for driving motor generator MG2 to converter 12. And a control signal for instructing regeneration to be returned to the side. These motor generator MG2 control commands (MG2 control commands) are output to inverter 14.

  Converter control unit 360 provides a control signal for instructing boosting to converter 12, a control signal for instructing step-down instruction, and a shutdown signal for instructing prohibition of operation so that DC voltage VH is controlled in accordance with a control command from distribution unit 340. Is generated. The charge / discharge power of the battery 10 is controlled by the voltage conversion of the converter 12 according to these control signals.

  Next, the operation of the ECU 30, particularly the operation when the power mode is selected, will be described with reference to the drawings. FIG. 4 is a flowchart showing a traveling mode switching operation in the ECU 30. The processing of this flowchart is executed every predetermined time or every time a predetermined condition is satisfied when the hybrid vehicle 5 is in a travelable state.

  Referring to FIG. 4, first, ECU 30 functioning as travel mode selection unit 310 includes a power switch signal Psw from power switch 90, a vehicle speed V from vehicle speed sensor 100, and a travel mode flag FM indicating the current travel mode. A process of receiving data necessary for travel control is executed (step S01).

  Next, the traveling mode selection unit 310 determines whether or not the input power switch signal Psw is in an on state, that is, whether or not the power mode is selected by the driver (step S02). When the power switch signal Psw is not in an on state, that is, when the power mode is not selected by the driver (NO in step S02), the processing related to the travel mode switching operation ends. In this case, the travel mode selection unit 310 sets the travel mode to the current travel mode, that is, the normal mode.

  On the other hand, when the power switch signal Psw is in the on state, that is, when the power mode is selected by the driver (in the case of YES in step S02), the traveling mode selection unit 310 displays the vehicle speed sensor 100. Based on the vehicle speed V from MG2 and the lock determination flag FLC from the MG2 lock detection unit 300, it is determined whether or not a lock state has occurred on the wheels of the hybrid vehicle 5.

  Specifically, the ECU 30 first determines whether or not the vehicle speed V from the vehicle speed sensor 100 is equal to or less than a predetermined threshold value Vth (step S03). This threshold value Vth is set within a very low speed range including vehicle speed = 0, assuming that the hybrid vehicle 5 is locked on a level difference or an uphill road. When vehicle speed V is equal to or lower than threshold value Vth (YES in step S03), traveling mode selection unit 310 then determines whether or not the motor generator MG2 is locked based on lock determination flag FLC. Determination is made (step S04). In hybrid vehicle 5 according to the present embodiment, as shown in FIG. 2, motor generator MG2 is mechanically coupled to output member 155 so as to apply power between output member 155 and the drive wheels. Configured. Therefore, by detecting whether or not the motor generator MG2 is locked, it is possible to determine whether or not the wheel is locked.

  When lock determination flag FLC is set on, that is, when a locked state is generated in motor generator MG2 (in the case of YES in step S04), traveling mode selection unit 310 selects the power mode. It is prohibited (step S05). As a result, the normal mode is maintained as the travel mode despite the power switch 90 being turned on.

  That is, when the ECU 30 executes the processes shown in steps S02 to S05 in FIG. 4 and the power mode is selected by the driver, the normal mode is started when the wheel is locked. Switching the driving mode to the power mode is prohibited. As a result, the wheel is locked and a driving force unintended by the driver is generated in a situation where the driver needs to finely adjust the amount of accelerator operation in order to escape the wheel from the locked state. Can be suppressed.

  On the other hand, when the power mode is selected by the driver (YES in step S02) and when vehicle speed V from vehicle speed sensor 100 exceeds threshold value Vth (NO in step S03). The traveling mode selection unit 310 determines whether or not the traveling mode previously set in this routine is the power mode based on the traveling mode flag FM (step S06). When it is determined that the previous travel mode is the power mode (YES in step S06), travel mode selection unit 310 maintains the power mode as the travel mode, and the process related to the travel mode switching operation ends. (Step S07).

  Further, when the power mode is selected by the driver (YES in step S02), vehicle speed V from vehicle speed sensor 100 is equal to or lower than threshold value Vth (in the case of YES in step S03), and the motor Even when generator MG2 is not locked (NO in step S04), traveling mode selection unit 310 based on traveling mode flag FM indicates that the traveling mode previously set in this routine is the power mode. Is determined (step S06). When it is determined that the previous travel mode is the power mode (YES in step S06), travel mode selection unit 310 maintains the power mode as the travel mode, and the process related to the travel mode switching operation ends. (Step S07).

  On the other hand, when it is determined in step S06 that the travel mode previously set in this routine is the normal mode (NO in step S06), travel mode selection unit 310 permits selection of the power mode. Is done. Therefore, travel mode selection unit 310 sends a travel mode flag FM indicating that the power mode has been selected to travel control unit 330. Travel control unit 330 switches the travel mode of hybrid vehicle 5 from the normal mode to the power mode in accordance with travel mode flag FM from travel mode selection unit 310 (step S08).

  When switching the travel mode from the normal mode to the power mode, the travel control unit 330 uses the vehicle driving force set based on the accelerator opening Acc from the accelerator position sensor 44 in the normal mode, and the accelerator position sensor 44 in the power mode. The vehicle driving force is gradually increased until the vehicle driving force is set based on the accelerator opening Acc. In this way, the vehicle driving force is subjected to the gradual change process because the vehicle driving force with respect to the accelerator operation amount suddenly increases immediately after shifting from the normal mode to the power mode, thereby giving the driver a feeling of popping out of the vehicle. This is because there is a fear.

  FIG. 5 is a flowchart illustrating a subroutine of step S08 (travel mode switching process) in FIG.

  Referring to FIG. 5, first, traveling control unit 330 sets a value 0 to flag F2 (step S11), and sets a temporary execution accelerator opening Accpow using a power mode map (step S12). The flag F2 is set to 0 when the processing for setting the accelerator opening Acc * for execution is executed for the power mode. In step S12, the travel control unit 330 stores in advance a map of the accelerator opening degree Acc and the temporary execution accelerator opening degree Accpow shown in FIG. When given, the corresponding temporary opening accelerator opening Accpow is set with reference to the map.

  FIG. 6 shows an example of the power mode map. In the figure, a normal mode map described later is also shown. Referring to FIG. 6, in the normal mode map, provisional execution accelerator opening Accnor is determined to have linearity with respect to accelerator opening Acc in a range of 0 to 100%. On the other hand, in the power mode map, the accelerator opening Acc in the low accelerator opening region of the predetermined opening Acc0 or less has the same value as the temporary execution accelerator opening Accnor set by the normal mode map. The temporary opening accelerator opening Accpow has a linearity that is the temporary opening accelerator opening Accpow, and is larger than the temporary execution accelerator opening Accnor for an accelerator opening Acc larger than the predetermined opening Acc0. It is determined to have non-linearity. This is because, when creeping with the accelerator pedal fully closed when the vehicle is stopped, a slight open determination is made even if the driver does not depress the accelerator pedal if there is a shift in the fully closed position of the accelerator pedal. In this case, if the power mode map is determined so that the execution accelerator opening Acc * larger than the normal mode map is set over the entire opening range of 0 to 100% at this time (FIG. 6). This is because a large execution accelerator opening Acc * may be set to give the vehicle a feeling of popping out.

  Next, the traveling control unit 330 checks the value of the flag F1 (step S13). This flag F1 is set to a value of 0 when the processing for setting the accelerator opening Acc * for execution is executed for the normal mode. Considering immediately after switching from the normal mode to the power mode, the flag F1 is determined to be 0 (in the case of YES in step S13).

  The travel control unit 330 sets the temporary execution accelerator opening Accnor based on the accelerator opening Acc from the accelerator position sensor 44 with reference to the normal mode map of FIG. 6 (step S14). Then, the traveling control unit 330 calculates the opening difference ΔA by subtracting the temporary execution accelerator opening Accnor from the temporary execution accelerator opening Accpow set in step S12 (step S15). Next, the traveling control unit 330 sets a new opening correction amount Aset1 by adding a predetermined amount A1 to the opening correction amount Aset1 previously set in this routine (step S16), and the opening correction amount Aset1. The opening degree difference ΔA is compared (step S17).

  When it is determined that the opening correction amount Aset1 is less than the opening difference ΔA (NO in step S17), the traveling control unit 330 sets the opening correction amount Aset1 to the temporary execution accelerator opening Accnor set in step S14. The added one and the accelerator opening Acc * for execution are set (step S21), and the process is terminated.

  On the other hand, when it is determined that the opening correction amount Aset1 is equal to or larger than the opening difference ΔA (in the case of YES in step S17), the traveling control unit 330 sets a value 1 to the flag F1 (step S18), A value 0 is set to the opening correction amount Aset1 (step S19). Furthermore, traveling control unit 330 sets provisional execution accelerator opening Accpow set in step S12 to execution accelerator opening Acc * (step S20), and ends the process.

  Since the negative determination is made in step S13 after the value 1 is set in the flag F1, the process in step S20 for setting the temporary execution accelerator opening Accpow to the execution accelerator opening Acc * is repeated. Will be.

  Thus, when the normal mode is switched to the power mode, the execution accelerator opening Acc * is gradually changed from the temporary execution accelerator opening Accnor to the temporary execution accelerator opening Accpow using the rate processing. Thus, switching from the normal mode to the power mode can be performed smoothly. Therefore, when the selection of the power mode is permitted when the wheel has escaped from the locked state, the travel mode is switched from the normal mode to the power mode (step S08 in FIG. 4), immediately after the switch to the power mode, A large execution accelerator opening Acc * is set, so that the vehicle driving force suddenly increases, and it is possible to suppress giving the driver a feeling of popping out. The predetermined amount A1 shown in step S16 is a rate value used for rate processing, and is determined based on the specifications of the hybrid vehicle 5.

  When the execution accelerator opening Acc * is set according to the flowchart of FIG. 5, the traveling control unit 330 sets the torque required for the hybrid vehicle 5 based on the set execution accelerator opening Acc * and the vehicle speed V as The required torque Tr * to be output to the output member 155 and the power Pe * required for the engine ENG are set.

  Regarding the required torque Tr *, in this embodiment, the relationship between the execution accelerator opening Acc *, the vehicle speed V, and the required torque Tr * is stored in advance as a required torque setting map, and the execution accelerator opening Acc * is stored. When the vehicle speed V is given, the corresponding required torque Tr * is derived with reference to the required torque setting map. FIG. 7 shows an example of the required torque setting map.

  Travel control unit 330 determines an output request to motor generators MG1 and MG2 and an output request to engine ENG based on the set required torque Tr * and required power Pe *. The output request to motor generators MG1 and MG2 is set after limiting so that charging / discharging of battery 10 is performed within a power range (Win to Wout) in which charging / discharging of battery 10 is possible. That is, when the output power of battery 10 cannot be secured, the output from motor generator MG2 is limited.

  Distribution unit 340 calculates the torque and rotation speed of motor generators MG1 and MG2 in response to the output request to motor generators MG1 and MG2 set by travel control unit 330. Then, a control command for torque and rotation speed is output to inverter control unit 350, and at the same time, a control command value for voltage VH is output to converter control unit 360.

  On the other hand, the distribution unit 340 generates an engine control instruction indicating the engine power and the engine target rotation speed determined by the travel control unit 330. In accordance with this engine control instruction, fuel injection, ignition timing, valve timing, etc. of an engine ENG (not shown) are controlled.

  As for the correspondence between the embodiment of the present invention and the present invention, the normal mode corresponds to the “first travel mode” and the power mode corresponds to the “second travel mode”. The ECU 30 constitutes “detection means”, “switching means”, “lock detection means”, “prohibition means”, and “lock escape detection means”.

  As described above, in the vehicle according to the embodiment of the present invention, when it is detected that the wheel is locked even when the power mode is selected by the driver, the power is Switching to the mode is prohibited. Thereby, in a scene where a fine accelerator operation by the driver is required to escape the wheel from the locked state, it is possible to suppress the output of the driving force not intended by the driver.

  In addition, when switching to the power mode is permitted by removing the wheel from the locked state, the vehicle driving force is changed from the vehicle driving force set based on the accelerator opening in the normal mode to the accelerator opening in the power mode. By slowly changing the vehicle driving force set based on this, it is possible to suppress the feeling of popping out that can be given to the driver immediately after switching to the power mode.

  In the above-described embodiment, a hybrid vehicle is illustrated as a representative example of the vehicle. However, the present invention has a normal mode corresponding to normal traveling and a vehicle driving force with respect to the same accelerator operation amount larger than that in the normal mode. Any one of the power modes can be applied to a vehicle configured to be selectable by the driver. For example, the present invention can also be applied to ordinary vehicles, electric vehicles, fuel cell vehicles, and the like that use only the engine as a drive source. Further, when applied to a hybrid vehicle, a hybrid vehicle having a hybrid configuration different from the configuration of FIG. 1 (for example, a so-called series hybrid configuration or an electric distribution type hybrid configuration) may be used.

  In the above-described embodiment, the power mode is selected as the travel mode to generate a driving force higher than that of the normal travel. However, the present invention is a vehicle having the power mode as one travel mode. The present invention is not limited to this, and can be applied to a vehicle having a function of increasing the vehicle driving force more than that during normal traveling in accordance with a scene where acceleration is required.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  5 Hybrid vehicle, 10 Battery, 12 Converter, 14, 22 Inverter, 20 Power conversion unit, 40 Handle, 44 Accelerator position sensor, 46 Brake pedal position sensor, 48 Shift position sensor, 51, 52 Rotation angle sensor, 70L, 70R Front wheel , 80L, 80R Rear wheel, 90 Power switch, 100 Vehicle speed sensor, 131, 136 Stator, 132, 137 Rotor, 133, 138 Stator core, 134, 139 Three-phase coil, 150 Crankshaft, 151, 162 Sun gear, 152, 168 Ring gear , 153, 164 Pinion gear, 154, 166 Planetary carrier, 155 Output member, 160 Output shaft, 170 Counter drive gear, 300 Lock detector, 310 Travel Mode selection unit, 320 charge / discharge control unit, 330 travel control unit, 340 distribution unit, 350 inverter control unit, 360 converter control unit, DEF differential gear, ENG engine, MG1, MG2 motor generator, RD reducer, RG power transmission Reduction gear.

Claims (4)

A vehicle having a first travel mode and a second travel mode in which the vehicle driving force for the same accelerator operation amount is greater than the first travel mode,
Detecting means for detecting a request for switching to the second traveling mode from the driver;
A switching means for switching the vehicle to the second traveling mode by increasing a vehicle driving force when the switching request is detected, compared to the first traveling mode;
Lock detecting means for detecting a locked state of the wheel when the switching request is detected;
A vehicle comprising: prohibiting means for prohibiting switching to the second travel mode by the switching means when the locked state of the wheels is detected. Lock escape detecting means for detecting that the wheel has escaped from the locked state during a period in which switching to the second traveling mode is prohibited by the prohibiting means;
An accelerator operation detecting means for detecting the driver's accelerator operation amount;
The prohibiting means permits the switching to the second traveling mode by the switching means when it is detected that the wheel has escaped from the locked state,
The switching means has a first vehicle driving force that is set based on the detected accelerator operation amount in the first traveling mode when the prohibiting means permits switching to the second traveling mode. 2. The vehicle according to claim 1, wherein the vehicle driving force is gradually increased between the first vehicle driving force and the second vehicle driving force set based on the detected accelerator operation amount in the second travel mode. An electric motor mechanically coupled to a drive shaft for driving the wheel;
The vehicle according to claim 1 or 2, wherein the lock detecting means detects the locked state of the wheel when the vehicle speed is equal to or lower than a predetermined threshold value and the electric motor is in a locked state. A vehicle control method comprising: a first travel mode; and a second travel mode in which a vehicle driving force with respect to the same accelerator operation amount is greater than the first travel mode,
Detecting a request for switching to the second driving mode from the driver;
A step for switching the vehicle to the second traveling mode by increasing a vehicle driving force when compared with the first traveling mode when the switching request is detected by the detecting step; ,
A step for detecting a locked state of a wheel when the switching request is detected by the detecting step;
And a step of prohibiting switching to the second travel mode by the switching step when the wheel lock state is detected by the detecting step.

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