JP5811950B2 - Vehicle control apparatus and vehicle control method - Google Patents

Description

  The present invention relates to a vehicle, and more particularly to a vehicle control apparatus and a vehicle control method having a hill assist function that can easily start on a slope.

  In recent years, as an environment-friendly vehicle, electric power stored in a power storage device (for example, a secondary battery or a capacitor) is converted into driving force by a driving device such as a motor, and the vehicle travels, for example, an electric vehicle, a hybrid vehicle, and a fuel cell. Cars are attracting attention.

  Japanese Patent Application Laid-Open No. 2010-246307 (Patent Document 1) discloses that when a hill start (starting on a hill) is performed, a hill hold control that prevents sliding down is performed when a brake pedal is released from a user's foot. Is done by.

  And when acceleration operation is performed using a brake pedal, hill hold control is cancelled | released and a vehicle starts driving | running | working in the advancing direction with the drive force of a motor.

JP 2010-246307 A

  Conventional vehicles secure the braking force of the brake by the driving force of the motor when starting on a slope. For this reason, the electric power which is an energy source will be consumed. Further, when the motor continues the hill hold control, the current continues to concentrate on a specific one phase existing at the energization position at the rotation angle of the rotor, and heat is generated.

  Vehicles such as motors that are stopped are difficult to cool because there is no running wind, and measures such as lowering the upper limit of the load factor limit of the motor must be taken. There was a possibility that the drivability of would be impaired.

  An object of the present invention is to provide a vehicle control device and a vehicle control method that improve the drivability of starting on a slope.

  In summary, the vehicle controls a driving device and a braking device based on an operation of an accelerator pedal and an operation of a brake pedal, a driving device that applies a driving force to the wheel, a braking device that applies a braking force to the wheel, and an operation of an accelerator pedal. And a control device.

  When the state where the vehicle is stopped midway on the uphill road due to the uphill road stop torque using the drive force of the drive device, the control device controls the uphill road stop torque from the drive force of the drive device using the braking device. When the first control for shifting to motive power is executed, the accelerator pedal is operated in the acceleration direction after the execution of the first control, and a driving force exceeding the uphill road stop torque is output from the drive device Performs the second control for releasing the braking force by the braking device.

  Preferably, in the first control, the control device replaces the driving force of the driving device with a braking force using the braking device when the accelerator pedal is held at a position corresponding to the uphill road stop torque.

  More preferably, the control device releases the braking force when a stepping-up operation from a position corresponding to the uphill road stop torque of the accelerator pedal by the user is detected.

  More preferably, the control device prompts the user to switch from the accelerator pedal to the brake pedal in the first control.

  More preferably, the information processing apparatus further includes a notifying unit that notifies the user of an alarm when a state where the vehicle is stopped on the way of the uphill road is continued by the uphill road stop torque using the driving force of the drive device.

  More preferably, the control device releases the brake pedal after operating the braking device after operating the braking device from a state where the vehicle is stopped on the way of the uphill road by the uphill road stop torque using the driving force of the drive device, compared with the normal time. The braking device is controlled so as to loosen the braking force.

  More preferably, the control device controls the drive device to add an amount of drive force that cancels out the degree of release of the braking force of the brake device.

  More preferably, when the state where the vehicle is stopped in the middle of the uphill road by the uphill road stop torque using the driving force of the drive device further includes a storage unit that stores an accelerator opening, and the control device includes an accelerator When the brake pedal is released again after switching from the pedal to the brake pedal, the accelerator opening stored in the storage unit is read.

  In another aspect, the present invention is a vehicle control method, wherein the vehicle is based on a driving device that applies driving force to wheels, a braking device that applies braking force to wheels, an operation of an accelerator pedal, and an operation of a brake pedal. And a control device for controlling the driving device and the braking device.

  The control method includes a step of detecting a continuation of a state in which the vehicle is stopped on the way of the uphill road by the uphill road stop torque using the drive force of the drive device during the uphill running, and braking the uphill road stop torque from the drive force of the drive device. The step of executing the first control for shifting to the braking force using the device, and the operation of the accelerator pedal in the acceleration direction is performed after the execution of the first control, and the driving force exceeding the climbing road stop torque is driven. In the case of being output from the device, a step of executing a second control for releasing the braking force by the braking device is included.

  According to the present invention, the first control for shifting the stop torque by the driving force is performed by the control device, and the hill hold state is held by the uphill road stop torque given by the braking force.

  Further, when the driving force output from the driving device exceeds the uphill road stop torque, the braking force is released by the second control, and the vehicle can be restarted.

It is a block diagram which shows the structure of the vehicle according to this Embodiment. It is the graph which contrasted the output upper limit torque of the motor which falls by load factor restriction | limiting, the torque currently output, and the torque which assists a brake. It is a time chart which shows the relationship between a driving force and a braking force, showing a replacement time and a stepping time. 3 is a flowchart illustrating driving force control of the vehicle according to the first embodiment. 6 is a flowchart illustrating driving force control for a vehicle according to a second embodiment. 10 is a flowchart for explaining driving force control of a vehicle in a modification of the second embodiment. 10 is a flowchart illustrating driving force control for a vehicle according to a third embodiment. In Embodiment 3, it is a flowchart explaining the process which cancels | releases brake operation among the driving force control of a vehicle.

  Hereinafter, embodiments 1 to 3 of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
1 to 4 show a vehicle 1 according to a first embodiment of the present invention. FIG. 1 is a block diagram showing the configuration of the vehicle. FIG. FIG. 3 is a time chart showing the relationship between the driving force and the braking force, and FIG. 4 shows the relationship between the driving time and the braking time. It is a flowchart explaining the driving force control of a vehicle.

First, the overall configuration of the vehicle 1 will be described with reference to FIG.
[Vehicle configuration]
The vehicle 1 travels by rotating the wheels 38. The vehicle 1 includes a driving device 11 that applies driving force to the wheels 38, a braking device 80 that applies braking force to the wheels 38, a notification unit 90 that notifies the user of an alarm, and each device of the vehicle 1 that includes the driving device 11. And a control device (Electronic Control Unit, hereinafter referred to as “ECU”) 50 for electronic control.

  The drive device 11 includes a power split mechanism in which the engine 8, the first electric motor MG1, the second electric motor MG2, the output shafts of the first and second electric motors MG1 and MG2, and the engine 8 are connected to three input shafts, respectively. 16 and the like. The braking device 80 includes a brake 88 that applies a frictional force to an element attached to the rotating shaft of the wheel 38, and a brake hydraulic pressure control unit 86 that supplies hydraulic pressure to the brake 88.

  More preferably, the vehicle 1 further includes a speed reduction device 20 as a transmission element disposed between the output shaft of the second electric motor MG2 and the drive shaft 79 for driving the wheels 38. A speed change device that can change the speed reduction ratio may be provided instead of the speed reduction device 20 or together with the speed reduction device 20.

  The vehicle 1 further includes an accelerator position sensor 82 that detects the amount of depression of the accelerator pedal. The drive request Acc is increased according to the depression amount of the accelerator pedal 81.

  When the driving device 11 generates a driving force in accordance with the driving request Acc when the traveling direction and the direction in which the driving force acts are opposite, or when shift control is performed, the driving device 11 operates in the operation prohibited region. When doing so, a transmission element such as a clutch may be controlled to a non-driving force transmission state.

  The vehicle 1 further includes an operation device 46 for switching a plurality of types of shift positions by manual operation, a brake pedal 85, a brake pedal stroke sensor 84, rotation sensors 72, 74, 76, 78, an inverter 62, and a power storage device. 60, a brake hydraulic pressure control unit 86, and a G sensor 36.

  The operation device 46 is provided with a shift position sensor 49 for detecting each shift position of the shift lever 48. The control device controls the signal Psh indicating the shift position of the shift lever 48, the number of operations at the “M” position, and the like. Output to 50.

  Control device 50 includes a storage unit 42, a slope determination unit 44, an engine control unit 58, a hybrid control unit 52, and a brake control unit 56.

  Among these, the memory | storage part 42 memorize | stores readable as a flag the event which the user switched from accelerator operation to brake operation, for example. Moreover, the memory | storage part 42 will memorize | store the accelerator opening degree at that time, when the vehicle 1 will be in the state which stopped on the slope. Then, after the accelerator pedal 81 is switched to the brake pedal 85, the accelerator opening can be read from the storage unit 42 when the brake pedal 85 is released again.

  The slope determination unit 44 determines whether or not the vehicle 1 exists in the middle of the uphill road according to various signals and various conditions that are input. For the determination by the slope determination unit 44, an acceleration signal sent from the G sensor 36 or a drive request Acc corresponding to the depression amount of the accelerator pedal 81 sent from the accelerator position sensor 82 is used.

  Further, a braking force request according to the depression amount of the brake pedal 85 detected by the brake pedal stroke sensor 84 is used for the determination by the slope determination unit 44. The result determined by the slope determination unit 44 is output to the hybrid control unit 52.

  The engine control unit 58 or the hybrid control unit 52 of the control device 50 controls the driving force of the engine 8 or the second electric motor MG2 based on the operation of the accelerator pedal 81.

  That is, the engine control unit 58 outputs the engine control signal, thereby controlling the rotational driving force of the engine 8 and generating the driving force required for traveling of the vehicle 1 from the wheels 38. The engine control signal is obtained from a drive request Acc input from the accelerator position sensor 82 to the hybrid control unit 52 based on the depression amount of the accelerator pedal 81. The engine control unit 58 outputs a drive request Acc adjusted by a detection value such as the engine speed Ne sent from the rotation sensor 72 as an engine control signal.

  The engine control signal is input to the engine 8 to perform engine driving force control such as ON / OFF of the engine 8 and the rotational speed of the engine 8. The rotational driving force of the engine 8 is transmitted to the power split mechanism 16.

  Further, the hybrid controller 52 receives the rotation speed Nm of the second electric motor MG <b> 2 provided from the rotation sensor 76. Further, the rotation speed Np of the drive shaft 79 provided from the rotation sensor 78 is input to the hybrid control unit 52. Then, the hybrid control unit 52 obtains the vehicle speed V based on the rotation speed Nm or the rotation speed Np.

  Further, the hybrid control unit 52 calculates and uses the drive request Acc based on the vehicle speed. The drive request Acc is output from the hybrid control unit 52 as a motor control output signal.

  The motor control output signal is output to the second electric motor MG2 via the inverter 62, and motor driving force control such as the rotational speed is performed. The rotational driving force of engine 8 and second electric motor MG2 is transmitted to power split mechanism 16. The power split mechanism 16 rotates the wheel 38 provided on the drive shaft 79 via the speed reducer 20 using the rotational drive force of at least one of the engine 8 and the second electric motor MG2, and the drive device 79 Driving power.

  The drive shaft 79 is provided with a brake 88 of the braking device 80. The braking device 80 includes a brake hydraulic pressure control unit 86 that supplies hydraulic pressure to the brake 88.

  Further, a deceleration command is output from the brake control unit 56 provided in the control device 50 to the brake hydraulic pressure control unit 86 so as to control the brake 88 based on the operation of the brake pedal 85.

The brake hydraulic pressure control unit 86 receives the deceleration command and supplies hydraulic pressure to the brake 88.
The brake 88 generates a frictional force corresponding to the hydraulic pressure, and even if the vehicle 1 decelerates and stops in the middle of an uphill road, the brake 88 is prevented from sliding down by its own weight.

  The deceleration command is given from the hybrid control unit 52 to the brake hydraulic pressure control unit 86 via the brake control unit 56. The hybrid control unit 52 cooperates with the driving force control by the engine control unit 58 and the braking force control by the brake hydraulic pressure control unit 86.

  In other words, when the hill hold state in which the vehicle 1 is stopped while traveling uphill is continued, the control device 50 shifts the hill stop torque from the driving force generated by the driving device 11 to the braking force using the braking device 80. Then, stop torque replacement control is performed as the first control to be replaced.

  Further, when the driving force exceeding the hill hold state is output from the driving device 11 and applied to the wheel 38 by acceleration by the operation of the accelerator pedal 81, the control device 50 performs the second control for releasing the braking force by the braking device 80. The re-start control is performed.

[Motor load factor limit]
FIG. 2 shows the output upper limit torque TMAX of the second electric motor MG2 that decreases due to the load factor limit (WOUT) and the drive torque TM that is actually output from the drive device 11, and the braking force TBA for the brake assist is shown. It is the graph made to contrast.

  The torque required to stop the uphill road is indicated by a line extending along the time axis TIME from the vicinity of the zero point on the vertical axis.

  If the total value of the driving torque TM and the braking force TBA is the same as the torque necessary for stopping the hill, the uphill traveling stop torque is in a state where the vehicle 1 is stopped during the uphill traveling.

Here, the state where the vehicle 1 is stopped on the uphill road is referred to as a so-called hill hold state.
In this hill hold state, a drive that is output from the drive device 11 by a brake hold state in which the brake 88 is activated and the vehicle 1 is stopped, and an accelerator hold operation in which the user's foot keeps stepping on the accelerator pedal 81 by a certain amount on an uphill road. There is an accelerator hold state in which the torque TM balances with the force for lowering the vehicle 1 to stop the vehicle.

  Unlike the hill hold state, when the total value of the driving torque TM and the braking force TBA is less than the torque necessary for stopping the hill, the vehicle 1 slides down from the hill.

  Further, when the hill hold control is continued by the second electric motor MG2, the current continues to concentrate on a specific one phase existing at the energization position at the rotation angle of the rotor with the passage of time, and the temperature rises. When the temperature of the second electric motor MG2 rises, the load factor is limited. When the load factor is limited, the output upper limit torque TMAX gradually decreases.

  As shown after time t1 in FIG. 2, the drive torque TM decreases with the output upper limit torque TMAX with a certain margin allowance α so as not to exceed the output upper limit torque TMAX. At that time, the braking force TBA applied by the braking device 80 is added to the driving torque TM to generate a torque necessary for stopping the slope.

  At time t1, the drive torque TM is reduced by the braking force TBA. For this reason, after the time t1, the current concentrated on the specific one phase decreases, and the temperature decreases. Therefore, the restriction on the load factor is eased, and the value of the output upper limit torque TMAX is recovered.

[Driving force and braking force]
FIG. 3 is a time chart showing the relationship between the driving force and the braking force at the time of replacement and the time of stepping on.

  At time t1, a switching process is performed in response to the accelerator pedal 81 being continuously depressed in a state corresponding to the stop torque for a predetermined time.

  At time t1 when the driving torque A is replaced with the braking force B, the decrease amount A1 of the driving torque A and the increased braking force B1 are set to the same amount. For this reason, even if the driving torque A is replaced with the braking force B, the sum of the driving torque A and the braking force B does not change, and the vehicle 1 does not slide down the slope.

  At time t2, the accelerator pedal 81 is stepped on more than the state corresponding to the stop torque. At time t2, the increased driving torque A2 is set larger than the decreased braking force B1.

  At time t2, as the braking force B is released gradually, a driving torque A3 larger than the driving request Acc is added.

  After time t2, the braking force B is gradually removed. The change in the braking force B is offset by the change in the drive torque A3 added to the drive force (broken line) corresponding to the drive request Acc. For this reason, the user can obtain drivability close to the desired drive request Acc without being aware of the braking force B even when the vehicle restarts from the slope.

FIG. 4 is a flowchart for explaining the driving force control of the vehicle 1 according to the first embodiment.
First, when processing control is started, in step S10 of this flowchart, it is determined whether or not the traveling state of the vehicle 1 is the accelerator ON state and the shift position is in the driving force range. The accelerator ON state is a state where the accelerator pedal is depressed. The driving force range is, for example, the D range (drive range), and the P range (parking range) and the N range (neutral range) are not driving ranges.

  The drive request Acc sent from the accelerator position sensor 82 that detects the depression amount of the accelerator pedal 81 is input to the hybrid control unit 52.

  Each shift position of the shift lever 48 provided in the operating device 46 is detected by the shift position sensor 49 and is input to the control device 50 as a signal Psh indicating the shift position of the shift lever 48.

  If it is determined in step S10 that the accelerator is on and the shift position is in the driving force range (YES in step S10), the control device 50 proceeds to the next step S11. If it is determined that the accelerator is not ON or the shift position is not in the driving force range (NO in step S10), the process proceeds to return.

  In step S11, the detected value of the brake pedal stroke sensor 84 by the brake pedal 85 is sent to the brake control unit 56, and it is determined whether or not the braking force is OFF. If the braking force by the brake 88 is OFF (YES in step S11), the process proceeds to the next step S12, and if the braking force by the brake 88 is not OFF (NO in step S11), the process proceeds to return. .

  In step S12, it is determined whether or not the vehicle 1 is stopped. If the vehicle speed is near 0 km / h, the hybrid control unit 52 determines that the vehicle is stopped (YES in step S12), proceeds to step S13, and if the vehicle speed is not near 0 km / h. Determines that it has not stopped (NO in step S12) and proceeds to return.

  In step S13, it is determined whether or not the vehicle 1 is stopped on a slope. The slope determination unit 44 of the control device 50 determines whether or not the road is a slope based on the acceleration signal sent from the G sensor 36, the depression amount of the accelerator pedal 81 sent from the accelerator position sensor 82, and the like.

  The slope determination unit 44 proceeds to the next step S14 when the vehicle 1 is stopped on the slope (YES in step S13), and returns when it is determined that the vehicle 1 is not a slope (NO in step S13). Proceed with the process. Note that this step S13 may not be performed, and if the slope determination is not performed, the process proceeds directly from step S12 to step S14.

  In step S14, it is determined whether or not a so-called accelerator hold operation in which the user's foot continues to step on the accelerator pedal 81 is continued.

  The vehicle 1 can be stopped on a slope without using the brake 88 by maintaining the accelerator at a certain opening. Therefore, it is possible to determine whether or not the accelerator hold control is being executed based on the position of the accelerator pedal 81 detected by the accelerator position sensor 82.

  That is, in step S14, when the accelerator hold state is continued for a certain time (YES in step S14), the process proceeds to the next step S15, and when the accelerator hold operation is released (NO in step S14). The process proceeds to return.

  In step S15, the slope stop torque is automatically switched from the driving force based on the accelerator command to the braking force even in the accelerator hold state.

  At time t1 shown in FIG. 3, the driving force is shifted to the braking force, and the replacement stop torque replacement control is performed. In this embodiment, the decrease amount A1 of the drive torque A and the increased braking force B1 are set to the same amount. For this reason, even if the drive torque A is replaced (replaced) with the braking force B, the sum of the drive torque A and the braking force B does not change. Therefore, the vehicle 1 does not slide down from the slope and the hill hold state is maintained. In addition, the user keeps stepping on the accelerator pedal 81 by a certain amount, and therefore hardly notices that the driving torque A has been replaced with the braking force B.

  In this embodiment, the increased driving torque A2 is set to be larger than the reduced braking force B1, and at time t2, the driving torque A3 larger than the driving request Acc is set in accordance with the release of the braking force B. The added driving torque A is applied to the wheel 38. For example, the driving force can be quickly output from the second electric motor MG2 with a small amount of heat generation up to (balance + start command value). For this reason, the vehicle 1 does not slide down from the slope and the hill hold state is maintained.

  In addition, at time t1 shown in FIG. 3, the braking force B set to the same amount as the decrease amount A1 of the drive torque A is increased at one time and the replacement is performed, but this is not a limitation. The driving torque A may be gradually decreased, and the braking force B may be gradually increased instead, and the ratio according to the switching speed and the switching stage is not particularly limited.

  When the process proceeds to step S16, the user's intention to restart is determined. If acceleration by stepping on the accelerator pedal 81 is detected by the accelerator position sensor 82 in step S16 (YES in step S16), the process proceeds to step S17. In addition, if no increase is detected due to acceleration by the operation of the accelerator pedal 81, the process proceeds to return.

  When the accelerator pedal 81 is further depressed by the user's intention and the acceleration operation is performed, a driving force exceeding the balance in the hill hold state is output from the driving device 11 to rotate the wheel 38.

  At this time, after time t2 shown in FIG. 3, the braking force B is gradually removed, so that the gradual release delay generated in the brake 88 is offset by the added drive torque A3.

  For this reason, the user can obtain drivability close to the desired drive request Acc without being aware of the braking force B even when the vehicle restarts from the slope.

  In step S17, a driving force is generated by the driving device 11, and the braking force by the braking device 80 is gradually released.

  After time t2 shown in FIG. 3, the release delay in which the braking force B is gradually released is offset by the added driving torque A3. For this reason, even if the user restarts from the slope, the user can obtain drivability close to the desired drive request Acc without being aware of the braking force B, and when the process of step S17 is completed, the process is repeated with a return. .

  In the first embodiment, the control device 50 performs the re-start control as the second control, and by the braking force of the braking device 80 until the driving force equal to or higher than the uphill road stop torque is output from the driving device 11, The vehicle 1 is held in a hill hold state. For this reason, the possibility that the vehicle 1 slides down on the slope during the pedal change operation is reduced.

  And if the driving force exceeding the uphill road stop torque holding a hill hold state is output from the drive device 11, the braking force by the braking device 80 used for the uphill road stop torque is released.

  Therefore, it is possible to quickly re-start the slope from a state where the driving force of the drive device 11 is not used as the uphill stop torque. As described above, in the vehicle 1 according to the first embodiment, the power consumption of the power storage device 60 can be suppressed in the hill hold state, and the drivability after the hill restarts can be improved.

  Even when the second electric motor MG2 is in the hill hold state and stopped at a specific rotation angle of the rotor, the braking force by the braking device 80 is replaced with the rotational driving force of the second electric motor MG2, and the driving force is in the hill hold state. It is no longer necessary to use for maintenance. For this reason, current does not continuously concentrate on a specific one phase, and heat generation is suppressed.

  Therefore, the load factor of the motor is limited, and it is not necessary to take measures such as lowering the upper limit value of the output, and the vehicle 1 is uphill as in the conventional hill hold state where the upper limit value is lowered by heating gradually. There is no risk of sliding down.

  In addition, the motor load factor is limited when driving after restarting from the hill hold state, compared to when the motor load factor is limited and the upper limit of the output is lowered and the vehicle must restart. Thus, the drivability of the vehicle 1 can be kept good because the desired rotational driving force of the second electric motor MG2 can be obtained.

[Embodiment 2]
FIG. 5 is a flowchart illustrating drive force control for a vehicle according to Embodiment 2 of the present invention. Of the steps shown in FIG. 5, the steps having the same contents as the steps shown in FIG. 4 have already been described, and thus detailed description will not be repeated here.

  Steps S20 to S23 in the flowchart of FIG. 5 are executed by the control device 50 in the same manner as steps S10 to S13 in the flowchart of FIG.

  First, when the processing control by the control device 50 is started, it is determined that the processing of step S20 to step S23 is completed and the vehicle 1 has stopped on the slope without the user stepping on the brake pedal 85 (in step S23). YES), control device 50 advances the process to step S24.

  In step S24, the hybrid control unit 52 causes the notification unit 90 to output a warning. The warning is performed by at least one of sound and display. Note that the warning may be performed by other methods such as vibration, lighting, and flashing light as long as the warning can be recognized by the user even if it is not sound or display.

  The content of the warning may be anything as long as the content of the warning is detected by the accelerator position sensor 82 to prompt the user to switch to the brake pedal 85. Good.

  In the brake hold state in which the brake pedal 85 is depressed from the beginning, it is not necessary to use the driving force of the second electric motor MG2 as the uphill road stop torque, and it is not necessary to limit the load factor of the motor. For this reason, no warning is output from the notification unit 90.

  In step S25, the hybrid control unit 52 determines whether or not the user has switched from the accelerator pedal 81 to the brake pedal 85 according to the switch warning.

  In the determination by the hybrid control unit 52, the fact that the user has switched from the accelerator pedal 81 to the brake pedal 85 (flag F = 0 → F = 1) is stored in the storage unit 42 as a flag (F = 1), for example. . Then, when the determination is performed by the hybrid control unit 52, the flag (F = 1) stored in the storage unit 42 is called to perform the determination.

  If the accelerator pedal 81 is switched to the brake pedal 85 (YES in step S25), the process proceeds to the next step S26, and if not, the process proceeds to return.

  In step S <b> 26, control is performed to change the hill hold start threshold value so that a user who has switched in accordance with the warning can easily start hill hold control using the brake pedal 85.

  As the control for changing the hill hold start threshold, for example, the stepping amount of the brake pedal 85 is changed shallowly, or the additional time required for entering the hill hold control is shortened.

  Furthermore, in step S26, when the accelerator pedal 81 is depressed again, control is performed to reduce the brake release speed so that the brake is released gently. When the process of step S26 ends, the process proceeds to return.

  The control for slowing down the brake release speed after the brake release is stored in the storage unit 42 as a flag (F = 1), and the user switches from the accelerator pedal 81 to the brake pedal 85 (flag F = 0 → F = 1).

  Based on the flag stored in the storage unit 42, the hybrid control unit 52 reduces the brake release speed by the brake pedal stroke sensor 84 detecting a brake release in which the user's foot is separated from the accelerator pedal 81. Control is performed.

  By reducing the brake release speed, it is possible to reduce the possibility that the vehicle 1 will immediately slide down even if the user releases the brake when restarting from the middle of the uphill road.

  Even if the vehicle is stopped on the uphill road, if the brake pedal 85 is being depressed from the beginning, it is determined that the normal slip suppression control is sufficient. For this reason, no warning is output from the notification unit 90.

[Modification]
FIG. 6 is a flowchart for explaining the driving force control as a modification of the driving force control of the vehicle according to the second embodiment of the present invention. Of the steps shown in FIG. 6, the steps having the same contents as the steps shown in FIG. 5 have already been described, and detailed description thereof will not be repeated here.

  This modification is performed alone or together with the drive control of the vehicle according to the second embodiment. First, when processing control is started, steps S30 to S33 in the flowchart of FIG. 6 are executed by the control device 50 in the same manner as steps S20 to S23 in the flowchart of FIG.

  If the hybrid control unit 52 determines that the slope determination unit 44 is a slope in the slope determination in step S33 (YES in step S33), the process proceeds to step S34.

  Moreover, if the slope control part 44 determines with the slope determination part 44 not being a slope in step S33, it will advance a process to a return. Then, similarly to step S23, when the slope determination is not performed in step S33, the process proceeds to step S34 after the stop determination in step S32 (YES in step S32).

  In step S34, the motor load factor is controlled (see FIG. 2), the driving torque TM = slope stop torque + α is obtained by calculation, and the hybrid controller 52 passes the inverter 62 through the second electric motor. MG2 is driven to rotate.

  When the process proceeds to the next step S35, it is determined whether or not the accelerator hold state is continued.

  When the drive request Acc output from the accelerator position sensor 82 is input to the hybrid control unit 52, it is determined in step S35 whether or not the accelerator hold operation is continued based on the drive request Acc.

  If it is determined in step S35 that the accelerator hold state is continuing, the process proceeds to the next step S36. If it is determined in step S35 that the accelerator hold state is not continued, the process proceeds to return.

  In step S36, as in step S15, the slope stop torque is automatically switched from the driving force based on the accelerator command to the braking force even during the accelerator hold operation in which the user's foot continues to step on the accelerator pedal 81.

  In the replacement performed in step S36, the braking force B set to the same amount as the decrease amount A1 of the drive torque A may be increased at one time as shown in FIG. Alternatively, the driving torque A may be decreased, and the braking force B may be gradually increased instead.

  When the process proceeds to step S37, in the vehicle 1 in the brake hold state, the driving force of the driving device 11 is removed, and the motor current is reduced to cool the second electric motor MG2. The set limit is restored.

  In step S <b> 38, the hybrid control unit 52 determines whether or not an acceleration operation has been performed by depressing the accelerator pedal 81 according to the intention of the user.

  If the acceleration operation is performed by stepping on the accelerator pedal 81 by the intention of the user, the process proceeds to step S39, where a driving force exceeding the balance of the hill hold state is output from the driving device 11, and the wheel 38 is rotated.

  At this time, as shown in FIG. 3, since the braking force B is gradually removed at time t2, the slow release delay generated in the brake 88 is offset by the added driving torque A3.

  If the acceleration operation is not performed by stepping on the accelerator pedal 81 in step S38, the process returns to step S37, and the recovery of the limit set in the motor load factor is continued.

  When the process of step S39 ends, the hybrid control unit 52 advances the process to return, and ends the process.

[Embodiment 3]
FIG. 7 is a flowchart illustrating driving force control for a vehicle according to Embodiment 3 of the present invention. Of the steps shown in FIG. 7, the steps having the same contents as the steps shown in FIG. 4 have already been described, and detailed description thereof will not be repeated here.

  First, when processing control is started, steps S50 to S54 in the flowchart of FIG. 7 are executed by the control device 50 in the same manner as steps S10 to S14 in the flowchart of FIG.

  Further, as in step S14, in step S54, it is determined whether or not the accelerator hold operation is continued.

  In step S54, the position of the accelerator pedal 81 detected by the accelerator position sensor 82 is maintained at a constant opening degree even when the vehicle is stopped, or the hill hold is determined by determining the accelerator hold operation by maintaining the predetermined time. When the control is being executed and the accelerator hold operation has been continued for a certain time or longer (YES in step S54), the process proceeds to the next step S55.

  If the accelerator hold operation has not been continued and is released (NO in step S54), the process proceeds to return.

  In step S <b> 55, the hybrid control unit 52 outputs a warning notified to the user from the notification unit 90. The warning is performed by at least one of sound and display.

  In step S56, the hybrid control unit 52 determines whether or not the user has switched from the accelerator pedal 81 to the brake pedal 85 according to the switch warning.

  If it is determined in the hybrid control unit 52 that the user has switched from the accelerator pedal 81 to the brake pedal 85, the process proceeds to the next step S57.

In step S57, the balance torque value is stored in the storage unit 42 as a numerical value.
When the process proceeds to the next step S58, the brake release time is delayed in step S48.

[Release brake operation]
FIG. 8 is a flowchart illustrating processing for releasing the brake operation in the driving force control of the vehicle according to the third embodiment. In the third embodiment, the vehicle 1 is prevented from slipping by outputting the balancing torque from the second electric motor MG2 without releasing the brake operation and waiting for switching to the accelerator pedal 81.

  The position of the balance torque of the accelerator pedal 81 stored in advance in the storage unit 42 is used in this driving force control. First, when this driving force control is started, it is determined in step S60 whether or not the brake operation has been released from ON to OFF. If it is determined that the brake operation has been released from ON to OFF, the process proceeds to the next step S61. If it is determined that it has not been released, the process proceeds to return.

  When the process proceeds to step S61, the hybrid control unit 52 outputs a balance torque. Along with the release of the brake operation, which is the initial operation of the step change, an accelerator opening corresponding to the depression amount of the accelerator pedal 81 that can obtain the balance torque stored in advance in the storage unit 42 is given, and the drive device 11 immediately starts the slope. Stop torque is generated. For this reason, the hill hold state is maintained without the vehicle 1 sliding down from the uphill road.

  When the process proceeds to step S62, the hybrid controller 52 starts the brake 88 after a certain delay time from the time when the user's foot is released from the brake pedal 85 or the time of switching to the accelerator pedal 81. Is released.

  In the driving force control of the third embodiment, the time during which the brake 88 is released is delayed compared to the normal brake release on a flat road or the like. For this reason, it is possible to reduce the possibility that the vehicle 1 will slip down when the vehicle 1 restarts on the uphill road.

  Further, in the third embodiment, when the user switches to the brake pedal 85 in accordance with the warning in step S56, the user's foot is released from the brake pedal 85 when switching from the brake pedal 85 to the accelerator pedal 81 again. At the time, the hybrid control unit 52 calls the balance torque value stored in the storage unit 42 and causes the second electric motor MG2 to output it.

  For this reason, the driving force corresponding to the balance torque value is quickly output from the second electric motor MG2 from the time when the user's foot is released from the brake pedal 85 to the time when the accelerator pedal 81 is reached. Then, the driving force of the second electric motor MG2 is replaced with the braking force of the brake 88, and the vehicle 1 can be prevented from sliding down due to the time lag of switching.

The embodiment described above will be summarized with reference to the drawings again.
As shown in FIG. 1, the vehicle 1 is based on a driving device 11 that applies driving force to the wheels 38, a braking device 80 that applies braking force to the wheels 38, an operation of the accelerator pedal 81, and an operation of the brake pedal 85. And a control device 50 that controls the driving device 11 and the braking device 80.

  When the state in which the vehicle 1 is stopped on the way of the uphill road is continued by the uphill road stop torque using the driving force of the drive device 11, the control device 50 determines the uphill road stop torque from the drive force of the drive device 11 as a braking device. The first control for shifting to the braking force using 80 is executed, and after the execution of the first control, the accelerator pedal 81 is operated in the acceleration direction, and the driving force exceeding the uphill road stop torque is applied to the driving device. 11 is executed, the second control for releasing the braking force by the braking device 80 is executed.

  Preferably, in the first control, the control device 50 uses the braking device 80 as the braking force of the driving device 11 when the accelerator pedal 81 is held at a position corresponding to the uphill road stop torque. Replace with.

  More preferably, the control device 50 releases the braking force when a stepping-up operation from a position corresponding to the uphill road stop torque of the accelerator pedal 81 by the user is detected.

  More preferably, the control device 50 prompts the user to switch from the accelerator pedal 81 to the brake pedal 85 in the first control.

  More preferably, the information processing apparatus 90 further includes a notification unit 90 that notifies the user of an alarm when the state in which the vehicle 1 is stopped in the middle of the uphill road is continued by the uphill road stop torque using the driving force of the drive device 11.

  More preferably, the control device 50 performs an operation of releasing the brake pedal 85 after operating the braking device 80 from a state where the vehicle 1 is stopped in the middle of the uphill road by the uphill road stop torque using the driving force of the drive device 11. Then, the braking device 80 is controlled so that the braking force is released more gently than usual.

  More preferably, the control device 50 controls the driving device 11 to add an amount of driving force that cancels out the degree of release of the braking force of the braking device 80.

  More preferably, when the state where the vehicle 1 is stopped in the middle of the uphill road due to the uphill road stop torque using the driving force of the drive device 11 is further provided with a storage unit 42 that stores the accelerator opening. The control device 50 reads the accelerator opening stored in the storage unit 42 when the brake pedal 85 is released again after switching from the accelerator pedal 81 to the brake pedal 85.

  More preferably, when the state where the vehicle 1 is stopped in the middle of the uphill road due to the uphill road stop torque using the driving force of the drive device 11 is further provided with a storage unit 42 that stores the accelerator opening.

  The control device 50 reads the accelerator opening stored in the storage unit 42 when the brake pedal 85 is released again after switching from the accelerator pedal 81 to the brake pedal 85.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Vehicle, 8 engine, 11 Drive apparatus, 16 Power split mechanism, 20 Reduction gear, 79 Drive shaft, 36 Sensor, 38 Wheel, 42 Memory | storage part, 44 Slope determination part, 46 Operation apparatus, 48 Shift lever, 49 Shift position sensor , 50 control device, 52 hybrid control unit, 56 brake control unit, 58 engine control unit, 60 power storage device, 62 inverter, 72, 74, 76, 78 rotation sensor, 80 braking device, 81 accelerator pedal, 82 accelerator position sensor, 84 brake pedal stroke sensor, 85 brake pedal, 86 brake hydraulic pressure control unit, 88 brake, MG1 first motor, MG2 second motor.

Claims (8)

A driving device that applies driving force to the wheels;
A braking device for applying a braking force to the wheel;
A control device for controlling the driving device and the braking device based on an operation of an accelerator pedal and an operation of a brake pedal;
When the state where the vehicle is stopped on the way of the uphill road by the uphill road stop torque using the driving force of the drive device, the control device determines the uphill road stop torque from the drive force of the drive device as the braking force. The first control for shifting to the braking force using the device is executed, and after the execution of the first control, the accelerator pedal is operated in the acceleration direction, and the driving force exceeding the uphill road stop torque is When output from the driving device, the second control is executed to release the braking force by the braking device and add an amount of driving force that cancels out the degree of release of the braking force of the braking device . Vehicle control device.   In the first control, the control device converts the driving force of the driving device into a braking force using the braking device when the accelerator pedal is held at a position corresponding to the uphill stop torque. The vehicle control device according to claim 1, wherein the vehicle control device is replaced.   3. The vehicle according to claim 1, wherein the control device releases the braking force when a stepping-up operation from a position corresponding to the uphill road stop torque of the accelerator pedal by the user is detected. Control device.   The vehicle control device according to claim 1, wherein the control device prompts the user to switch from the accelerator pedal to the brake pedal in the first control.   5. The vehicle according to claim 4, further comprising a notification unit that notifies a user of an alarm when a state in which the vehicle is stopped in the middle of the uphill road is continued by the uphill road stop torque using the driving force of the driving device. Control device.   The controller is configured to release the brake pedal from the normal state by operating the brake device from a state where the vehicle is stopped in the middle of the uphill road by the uphill road stop torque using the driving force of the drive device. The vehicle control device according to claim 1, wherein the braking device is controlled so that release of the vehicle is moderated. When the state of stopping the vehicle in the middle of the uphill road by the uphill road stop torque using the driving force of the drive device continues, the storage device further stores the accelerator opening,
Wherein the controller, after Stepping replacement from the accelerator pedal to the brake pedal, when released the brake pedal again, reads the accelerator opening stored in the storage unit, any one of claims 1 to 6 The vehicle control device described in 1. A vehicle control method comprising:
Vehicle
A driving device that applies driving force to the wheels;
A braking device for applying a braking force to the wheel;
A control device for controlling the driving device and the braking device based on an operation of an accelerator pedal and an operation of a brake pedal;
The control method is
Detecting the continuation of a state where the vehicle is stopped on the way uphill by the uphill road stop torque using the driving force of the drive device when running uphill;
Executing a first control for shifting an uphill stop torque from a driving force of the driving device to a braking force using the braking device;
When the accelerator pedal is operated in the acceleration direction after execution of the first control and a driving force exceeding the climbing road stop torque is output from the driving device, the braking force by the braking device is released. And executing a second control for adding an amount of driving force that cancels out the degree of release of the braking force of the braking device .

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