JP5287826B2 - Vehicle travel control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress uncomfortable feeling to a driver in automatic traveling such as cruise traveling. <P>SOLUTION: The traveling control device for a hybrid vehicle has a means which is operated by the start operation by the driver, calculates a target drive force for automatically adjusting a traveling state to a state which is set by the driver, and controls fuel supply to an engine. When target drive torque corresponding to the target drive force reaches a value smaller than a negative value cruise coast F/C determination value which is set beforehand, F/C processing for stopping the fuel supply to the engine is performed in a state that the start operation is detected, the engine transmits the drive forces to drive wheels, and the hybrid vehicle is decelerated in speed. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a vehicular travel control technique for a hybrid vehicle that travels using an engine and a motor as drive sources and uses at least one of the engine and motor according to the travel state.

  As a travel control device for a hybrid vehicle, for example, there is a technique described in Patent Document 1. In the travel control device of Patent Document 1, when there is no accelerator operation request from the driver, the engine is stopped to reduce fuel consumption, and the vehicle speed is controlled by the output of the motor.

JP 2005-160252 A

In a general hybrid vehicle travel control apparatus, when the engine is stopped as described above during automatic constant speed travel (cruise travel), fuel supply to the engine is stopped (fuel cut: hereinafter referred to as “F / C ”) and stop the engine. Here, the above-mentioned F / C is a target drive torque having a predetermined value (for example, in a state where the hybrid vehicle is decelerating in a traveling mode by an engine and a motor (hereinafter sometimes referred to as “HEV mode”). 1 [kW] equivalent torque). The “target driving torque” is a torque corresponding to the target driving force for automatically adjusting to the driving state set by the driver during automatic constant speed driving.
When the fuel is supplied again to the engine from the above-described F / C state (hereinafter sometimes referred to as “F / C recovery”), the target drive torque exceeds the predetermined value. In addition, fuel is supplied to the engine.

However, in a general hybrid vehicle travel control apparatus, the predetermined value is a value corresponding to the positive torque. For this reason, F / C and F / C recover frequently occur when the road surface resistance changes in a small downward slope or when following a preceding vehicle at a low speed during automatic constant speed traveling. . As a result, the engine is started and stopped in a short time, and the driver may feel uncomfortable due to the engine stop / start.
The present invention pays attention to the above points, and an object thereof is to suppress a sense of discomfort given to a driver in automatic traveling such as cruise traveling.

  In order to solve the above problems, the present invention operates by a driver's starting operation, calculates a target driving force for automatically adjusting to a driving state set by the driver, and controls fuel supply to the engine. A travel control apparatus for a hybrid vehicle including means. In the vehicular travel control apparatus of the present invention, when the target drive torque corresponding to the target drive force becomes less than a predetermined negative cruise coast F / C determination value, a process of stopping fuel supply to the engine is performed. This process is performed in a state where the activation operation is detected, and further, the engine transmits the driving force to the driving wheels and the hybrid vehicle is decelerated.

  According to the present invention, it is possible to suppress a sense of discomfort given to the driver in automatic traveling such as cruise traveling.

1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is a figure which shows the structural example of the hybrid system which concerns on embodiment based on this invention. It is a figure which shows the flow of a basic signal in the integrated controller which concerns on embodiment based on this invention. It is a figure which shows the functional block of the integrated controller which concerns on embodiment based on this invention. It is a flowchart which shows the process which a request | requirement electric power generation torque calculating part performs. It is a functional block of a target drive torque calculation part. It is a figure which shows the transition relationship of vehicle state mode. It is a functional block of a vehicle state mode determination part. It is a flowchart which shows the process of a cruise coast F / C determination process part. It is a time chart which shows the state in which the target drive torque is changing during cruise driving. It is a time chart which shows operation | movement of the hybrid vehicle provided with the vehicle travel control apparatus of this embodiment. It is a figure which shows the change of the cruise coast F / C determination value in consideration of MG lower limit torque.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment. The hybrid vehicle shown in FIG. 1 is an example of rear wheel drive, but the present invention is also applicable to front wheel drive. In the following description, the hybrid vehicle may be described as “vehicle” or “own vehicle”.

(Configuration of drive system)
First, the configuration of the drive system (power train) will be described.
As shown in FIG. 1, the power train of the present embodiment has a motor 2 and an automatic transmission 3, that is, AT (= transmission T) in the middle of a torque transmission path from the engine 1 to the left and right rear wheels (drive wheels). / M). Further, the power train of the present embodiment includes the first clutch 4 between the engine 1 and the motor 2, and the second clutch is provided in the torque transmission path between the motor 2 and the drive wheel (rear wheel). 5 is inserted.

In this example, the second clutch 5 constitutes a part of the automatic transmission 3 (= transmission T / M). The automatic transmission 3 is connected to drive wheels 7 (rear wheels) through a propeller shaft, a differential 6 (DF: differential gear), and a drive shaft.
The engine 1 is a gasoline engine or a diesel engine. The engine 1 can control the valve opening degree of the throttle valve and the like based on a control command from an engine controller 22 described later. A flywheel may be provided on the output shaft of the engine 1.

  The motor 2 is, for example, a synchronous motor in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The motor 2 can be controlled by applying a three-phase alternating current generated by an inverter 8 described later based on a control command from a motor controller 23 described later. The motor 2 can also operate as an electric motor that rotates by receiving power supplied from a battery 9 (described later) (this state is referred to as “powering”).

Further, when the rotor is rotated by an external force, the motor 2 functions as a generator that generates an electromotive force at both ends of the stator coil, and can charge the battery 9 (this operation state is expressed as “ Called "regeneration"). The rotor of the motor 2 is connected to the input shaft of the automatic transmission 3 via a damper (not shown).
The first clutch 4 is a hydraulic single-plate clutch interposed between the engine 1 and the motor 2. The first clutch 4 is engaged or disengaged according to the control hydraulic pressure created by the first clutch hydraulic unit so as to obtain the input target clutch transmission torque based on a control command from the AT controller 24 described later. It becomes. The engagement / release of the first clutch 4 includes slip engagement and slip release.

The second clutch 5 is a hydraulic multi-plate clutch. Based on a control command from the AT controller 24, the second clutch 5 is engaged or disengaged by a control hydraulic pressure generated by a second clutch hydraulic unit (not shown) so as to achieve a target clutch transmission torque. Become. The engagement / release of the second clutch 5 includes slip engagement and slip release.
The automatic transmission 3 has a stepped gear ratio such as a forward 7-speed reverse 1-speed or a forward 6-speed reverse 1-speed according to the vehicle speed or a shift accelerator opening degree input from the integrated controller 21 described later. A transmission that automatically switches. Here, the second clutch 5 is not newly added as a dedicated clutch, and some of the frictional engagement elements among the plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission 3 are diverted. And configure.

Here, in the present embodiment, the case where the second clutch 5 is configured as a part of the automatic transmission 3 (= transmission T / M) is illustrated, but the present invention is not limited to this. That is, the second clutch 5 may be configured to be disposed between the motor 2 and the automatic transmission 3 or between the automatic transmission 3 and the differential 6, for example.
Each wheel is provided with a brake unit (not shown). Each brake unit includes, for example, a disc brake and a drum brake. Each brake unit may be a hydraulic brake device or an electric brake device. Each brake unit applies a braking force to the corresponding wheel in response to a command from the brake controller 25. Note that the brake unit need not be provided on all wheels.

Moreover, in FIG. 1, the code | symbol 14 shows an electric sub oil pump and the code | symbol 15 shows a mechanical oil pump. These oil pumps 14 and 15 generate hydraulic pressure for each clutch. Reference numeral 10 denotes an engine rotation sensor that detects the rotation speed of the engine 1, and reference numeral 11 denotes a motor rotation sensor such as a resolver that detects the rotation of the motor 2.
In FIG. 1, reference numeral 12 denotes an AT input rotation sensor that detects the rotation of the input shaft of the transmission, and reference numeral 13 denotes an AT output rotation sensor that detects the rotation of the output shaft of the transmission. Moreover, the code | symbol 27 shows the wheel speed sensor which detects rotation of a wheel. The wheel speed sensor 27 may also be provided on a driven wheel (front wheel) (not shown).

FIG. 2 is a configuration diagram illustrating the control system for the power train shown in FIG.
Reference numeral 33 denotes an accelerator pedal operated by the driver. The accelerator opening APO of the accelerator pedal 33 is detected by the accelerator sensor 20. Then, the accelerator sensor 20 outputs the detected accelerator opening APO information to the integrated controller 21.
Reference numeral 34 denotes a pedal actuator. The pedal actuator 34 is an actuator that applies a pedal reaction force to the accelerator pedal 33. Here, the pedal reaction force has a magnitude corresponding to a command from the inter-vehicle distance controller 31.

Reference numeral 32 indicates a radar unit constituting the preceding vehicle detection means. The radar unit 32 detects a preceding vehicle ahead of the host vehicle, and outputs the detected preceding vehicle information to the inter-vehicle distance controller 31.
Reference numeral 27 denotes a wheel speed sensor. The wheel speed sensor 27 outputs the detected wheel speed information to the brake controller 25. Further, the vehicle speed information obtained from the wheel speed information is output from the brake controller 25 to the integrated controller 21 and the inter-vehicle distance controller 31.

Moreover, the code | symbol 35 shows the meter for showing a driving | running | working state to a driver | operator. The meter 35 displays information such as auto cruise.
Reference numeral 29 denotes a brake switch. The brake switch 29 detects an operation of a brake pedal (not shown).
Reference numeral 28 denotes a steering switch. The steering switch 28 is an operator for a driver to start cruise traveling, which is automatic constant speed traveling, and to change a traveling condition (target vehicle speed). Here, the cruise travel includes inter-vehicle controlled cruise travel in addition to automatic constant speed travel.

Reference numeral 30 denotes a cruise cancel switch. This cruise cancel switch 30 is an operator for instructing the end of cruise traveling, and is provided in the vicinity of the steering switch 28 and on the brake pedal.
Reference numeral 18 denotes a voltage sensor that detects the voltage of the battery 9, and reference numeral 19 denotes a current sensor that detects the current of the battery 9.

(Control system configuration)
Next, the configuration of the control system of the hybrid vehicle will be described.
The hybrid vehicle control system includes an engine controller 22, a motor controller 23, and an inverter 8, as shown in FIG. 2. The hybrid vehicle control system includes a battery controller 26, an AT controller 24, a brake controller 25, an integrated controller 21, and an inter-vehicle distance controller 31.

The engine controller 22, the motor controller 23, the AT controller 24, the brake controller 25, the inter-vehicle controller 31 and the integrated controller 21 are connected via a CAN communication line (not shown) capable of transmitting and receiving information to and from each other.
The engine controller 22 inputs engine speed information from the engine speed sensor 10. Then, the engine controller 22 outputs a command for controlling the engine operating point (Ne, Te) according to the target engine torque or the like from the integrated controller 21, for example, to a throttle valve actuator (not shown). Information about the engine speed Ne is acquired from the integrated controller 21 via the CAN communication line.

The motor controller 23 inputs information from the motor rotation sensor 11 that detects the rotor rotation position of the motor 2. The motor controller 23 outputs a command for controlling the motor operating point (Nm, Tm) of the motor 2 to the inverter 8 in accordance with the target motor torque, the rotational speed command, etc. from the integrated controller 21.
The battery controller 26 monitors the battery SOC that represents the state of charge of the battery 9 based on information from the voltage sensor 18 that detects the voltage of the battery 9 and information from the current sensor 19 that detects the current of the battery 9. Then, the battery controller 26 supplies information on the monitored battery SOC as control information of the motor 2 to the integrated controller 21 via the CAN communication line.

  The AT controller 24 inputs sensor information from a first clutch oil pressure sensor (not shown) and a first clutch stroke sensor (not shown). Then, the AT controller 24 sends a command for controlling engagement / disengagement of the first clutch 4 according to the first clutch control command (target first clutch transmission torque command) from the integrated controller 21 to the first clutch hydraulic unit. (Not shown).

  The AT controller 24 inputs sensor information from a wheel speed sensor 27 and a second clutch hydraulic pressure sensor (not shown). Then, the AT controller 24 sends a command for controlling the engagement / release of the second clutch 5 in response to the second clutch control command (target second clutch torque command) from the integrated controller 21 in the AT hydraulic control valve. Output to the second clutch hydraulic unit. Here, the output of the command for controlling the engagement / disengagement of the second clutch 5 is performed in preference to the control of the second clutch in the shift control.

  The brake controller 25 inputs sensor information from a wheel speed sensor 27 that detects each wheel speed of each wheel (four wheels) and sensor information from a brake stroke sensor (not shown). The brake controller 25 calculates a target deceleration based on a brake pedal stroke amount, a braking request amount from the inter-vehicle controller 31 and the vehicle speed in a preset control cycle.

Then, the brake controller 25 distributes the braking force to the cooperative regenerative braking request torque with the target deceleration as the rotational braking force and the target hydraulic braking force as the mechanical braking force (hydraulic braking force) as the regenerative cooperative brake control. Further, the brake controller 25 outputs the cooperative regenerative brake request torque to the motor controller 23 of the integrated controller 21.
The brake controller 25 outputs the target hydraulic braking force to the hydraulic braking force device. For example, the brake controller 25 performs regenerative cooperative brake control when the regenerative braking force is insufficient with respect to the required braking force obtained from the brake stroke BS or the like when the brake pedal is depressed.

And the said brake controller 25 is based on the regenerative cooperative control instruction | command from the integrated controller 21 so that the said insufficiency may be supplemented with mechanical braking force (hydraulic braking force or the braking force which the motor 2 generate | occur | produces). Take control.
Further, the inter-vehicle controller 31 receives information on the steering switch 28 set by the driver, cruise control operation permission state, and other necessary information from the integrated controller 21. When the inter-vehicle controller 31 determines that the inter-vehicle control for the preceding vehicle is to be performed based on the information from the integrated controller 21, the inter-vehicle controller 31 calculates the target acceleration and the target deceleration for realizing the target inter-vehicle distance and the target inter-vehicle time for the preceding vehicle. Calculate. This calculation is performed based on the own vehicle speed, information on the preceding vehicle based on detection by the radar unit 32 (such as an inter-vehicle distance and a relative speed).

Then, the inter-vehicle control controller 31 outputs the obtained target acceleration to the integrated controller 21 as inter-vehicle cruise request torque (ACC required torque). Further, the inter-vehicle controller 31 outputs the obtained target deceleration to the brake controller 25 as a braking request torque.
The inter-vehicle distance controller 31 includes a DCA control (Distance Control Assist) unit 31A. The DCA control unit 31A calculates a pedal reaction force command based on accelerator opening APO information received from the integrated controller 21, vehicle speed information based on detection by the wheel speed sensor 27, and information from the radar unit 32. Then, the DCA control unit 31A outputs the calculated reaction force command to the pedal actuator 34 as support information for the driver to keep the distance from the preceding vehicle. The pedal actuator 34 applies a reaction force to the input accelerator pedal 33.
The integrated controller 21 is responsible for managing the energy consumption of the entire vehicle and running the vehicle with the highest efficiency.

The integrated controller 21 inputs information from the engine speed sensor 10 that detects the engine speed Ne, and inputs information from the motor speed sensor 11 that detects the motor speed Nm. Further, the integrated controller 21 inputs information from the AT input rotation sensor 12 that detects the transmission input rotation speed, and inputs information from the AT output rotation sensor 13 that detects the transmission output rotation speed.
Further, the integrated controller 21 inputs accelerator opening APO information from the accelerator sensor 20 and inputs information on the storage state SOC of the battery 9 from the battery controller 26.

Further, the integrated controller 21 outputs information acquired via the CAN communication line.
Further, the integrated controller 21 performs operation control of the engine 1 according to a control command to the engine controller 22. The integrated controller 21 executes operation control of the motor 2 in accordance with a control command to the motor controller 23.
Further, the integrated controller 21 executes the engagement / disengagement control of the first clutch 4 and the engagement / disengagement control of the second clutch 5 according to the control command to the AT controller 24.

(Basic operation mode in hybrid vehicle)
Here, the basic operation mode in the hybrid vehicle of the present embodiment will be described.
If the battery SOC is low while the vehicle is stopped, the engine 1 is started to generate power, and the battery 9 is charged. When the battery SOC is in the normal range, the engine 1 is stopped while the first clutch 4 is engaged and the second clutch 5 is released.
At the time of starting by the engine 1, the motor 2 is rotated according to the accelerator opening APO and the battery SOC state to switch to power running / power generation.

On the other hand, at the time of starting by the motor 2, the driving force by the motor 2 is increased until the vehicle moves forward, and then the second clutch 5 is shifted from slip control to engagement. Here, at the time of starting by the motor 2, for example, when the output rotation of the automatic transmission 3 becomes negative due to rollback, slip control of the second clutch 5 is performed and the rotation of the motor 2 is maintained at the positive rotation. To do.
In the motor running (EV mode), the motor torque and battery output necessary for starting the engine 1 are ensured. In addition, when the vehicle speed of the host vehicle becomes equal to or higher than a predetermined vehicle speed (EV prohibited vehicle speed) set in advance based on a preset map or the like, the motor drive (EV mode) is shifted to the engine drive (HEV mode). Further, when the engine is running, the motor 2 assists the engine torque delay in order to improve the response when the accelerator pedal is depressed. That is, while the engine is running, there is a mode in which the vehicle runs with only the power of the engine 1 or with both the power of the engine 1 and the motor 2.

At the time of brake ON deceleration (deceleration accompanied by operation of the brake pedal), a deceleration force corresponding to the driver's brake operation is obtained by regenerative cooperative brake control.
At the time of shifting during engine traveling or motor traveling, the motor 2 is regenerated / powered to adjust the rotational speed associated with shifting during acceleration / deceleration, thereby performing smooth shifting without a torque converter.

Next, a part related to the present invention in the braking / driving control process executed by the integrated controller 21 will be described using FIGS. 3 and 4 with reference to FIGS.
FIG. 3 illustrates a schematic configuration diagram illustrating a basic flow of basic command values in the control of the integrated controller 21 of the present embodiment. FIG. 4 is a functional block diagram functionally illustrating the control of the integrated controller 21 of the present embodiment.

As shown in FIG. 4, the integrated controller 21 includes a required power generation torque calculation unit 21A, a required engine torque calculation unit 21B, a motor output possible torque calculation unit 21C, a target drive torque calculation unit 21D, and a vehicle state mode determination unit 21E. As shown in FIG. 4, the integrated controller 21 includes an engine start control unit 21F, an engine stop control unit 21G, a target engine torque calculation unit 21H, a target motor torque calculation unit 21J, and a target clutch torque calculation unit 21K.
The required power generation torque calculation unit 21A calculates the required power generation torque to be generated by the motor 2 based on vehicle speed information, battery information such as SOC from the battery controller 26, and the like.

Further, the required power generation torque calculation unit 21 </ b> A has a torque (hereinafter referred to as “MG”) that corresponds to a lower limit value of power that the motor 2 can input to the battery 9 by regeneration (hereinafter may be referred to as “battery input lower limit power”). May be described as “lower limit torque”).
Hereinafter, the process in which the required power generation torque calculation unit 21A calculates the MG lower limit torque will be described with reference to FIGS. 1 to 5 and the flowchart of FIG.

First, in step S10, a battery input limit value (PIN) that is a limit value (upper limit value) of power that can be input to the battery 9 is calculated based on battery information such as SOC from the battery controller 26, and step S20. Migrate to
In step S20, based on the battery input limit value (PIN) described above, the battery input lower limit power corresponding to the battery input limit value (PIN) is calculated, and the process proceeds to step S30.
In step S30, the battery input lower limit power corresponding to the above-described SOC is calculated based on the SOC, and the process proceeds to step S40.

In step S40, the battery input lower limit power corresponding to the voltage and current of the battery 9 is calculated based on information from the voltage sensor 18 and the current sensor 19 via the battery controller 26, and the process proceeds to step S50.
In step S50, the above-described MG lower limit torque is calculated based on the various battery input lower limit powers calculated in steps S20 to S40, and the process proceeds to step S60.

Here, when calculating the MG lower limit torque, the above-described various battery input lower limit powers are converted into the regenerative torque generated by the motor 2 and calculated.
In step S60, the MG lower limit torque calculated in step S50 is output to request engine torque calculation unit 21B and vehicle state mode determination unit 21E, and the process ends. Then return.

Hereinafter, the description will return to the portion related to the present invention in the braking / driving control processing executed by the integrated controller 21.
The required engine torque calculation unit 21B calculates the required engine torque that should be generated in the engine 1 based on the running state such as the vehicle speed and the required power generation torque calculated by the required power generation torque calculation unit 21A.
The motor output possible torque calculation unit 21C calculates motor output possible torque that the motor 2 can output based on battery information such as SOC from the battery controller 26, vehicle speed, and the like.

The target drive torque calculation unit 21D calculates a target drive torque to be targeted. The target drive torque calculation unit 21D includes a driver request torque calculation unit and an automatic control request torque calculation unit.
The driver request torque calculation unit calculates the driver request torque that is estimated to be requested by the driver based on the operation amount (accelerator opening APO) of the accelerator pedal 33 operated by the driver.
In addition, the automatic control request torque calculation unit calculates an automatic control request torque for automatically adjusting to a driving state of a driving condition (set vehicle speed) preset by the driver. Here, the calculation of the automatic control request torque is started by operating a steering switch that is an automatic travel control switch, and is ended by operating the cruise cancel switch 30.

Then, the target drive torque calculator 21D calculates the target drive torque based on the driver request torque calculated by the driver request torque calculator and the automatic control request torque calculated by the automatic control request torque calculator.
As shown in FIG. 6, the target drive torque calculation unit 21D of the present embodiment includes a driver request torque calculation unit 21Da, an automatic control request torque calculation unit 21Db, a first target drive torque calculation unit 21Dc, a vehicle speed limiter torque calculation unit 21Dd, The final target drive torque calculation unit 21De is provided.

The driver request torque calculation unit 21Da calculates the driver request torque based on at least the accelerator opening APO information of the accelerator pedal 33 and the vehicle speed. Further, in the example shown in FIG. 3, the driver request torque calculation unit 21Da inputs the accelerator opening APO and the transmission input rotation speed, and calculates the basic driver request torque with reference to the base torque map.
Further, the driver request torque calculation unit 21Da calculates the first correction torque based on the vehicle speed with reference to the creep / coast driving force table. Further, the second correction torque is calculated with reference to the MG assist torque MAP based on the power limit information based on the accelerator opening APO information, the transmission input rotation speed, the SOC, and the like.

Then, the driver request torque calculation unit 21Da obtains a final driver request torque based on the calculated basic driver request torque, the first correction torque, and the second correction torque.
The automatic control request torque calculation unit 21Db outputs the steering switch 28 and the ACC permission signal to the inter-vehicle control controller 31 and inputs the inter-vehicle cruise request torque (ACC required torque) from the inter-vehicle control controller 31. Further, the automatic control request torque calculation unit 21Db calculates a constant speed cruise request torque for feedback control to the set vehicle speed based on the set vehicle speed set by the steering ring SW and the current vehicle speed.

  Then, the automatic control request torque calculation unit 21Db converts either the inter-vehicle cruise request torque (ACC required torque) or the constant speed cruise request torque according to the presence or absence of the ACC operation (inter-vehicle control operation). Choose as. Here, during the ACC operation, processing is performed so that the inter-vehicle cruise request torque is prioritized and selected over the constant speed cruise request torque.

The first target drive torque calculator 21Dc performs a select high of the driver request torque calculated by the driver request torque calculator 21Da and the automatic control request torque calculated by the automatic control request torque calculator 21Db. Then, the larger torque of the driver required torque and the automatic control required torque is selected and output as the first target drive torque.
The vehicle speed limiter torque calculating unit 21Dd calculates a vehicle speed limiter torque for setting the vehicle speed to be equal to or lower than the upper limit vehicle speed based on the set vehicle speed set by the steering switch 28 and the current vehicle speed.

The final target drive torque calculation unit 21De performs a select low between the first target drive torque output by the first target drive torque calculation unit 21Dc and the vehicle speed limiter torque calculated by the vehicle speed limiter torque calculation unit 21Dd. That is, the target drive torque is obtained by limiting the first target drive torque with the vehicle speed limiter torque.
The vehicle state mode determination unit 21E determines a target vehicle state mode (EV mode, HEV mode) as a target. This determination is based on the vehicle state mode area map (EV-HEV transition map) based on the accelerator opening APO, vehicle speed information (or transmission output speed), motor output possible torque, required engine torque, and target drive torque. Do it by reference. This is because, for example, when the torque obtained by adding the cranking torque necessary for starting the engine 1 to the target drive torque for vehicle braking / driving control falls below the torque that the motor 2 can output, the mode is changed from the HEV mode to the EV mode. The operation mode changes.

Further, the vehicle state mode determination unit 21E sets the target target vehicle state mode to the HEV mode when there is a required engine torque due to a request such as battery charging. If the current vehicle state mode is the EV mode and the target vehicle state mode is the HEV mode, the engine start sequence is processed. Further, when the current vehicle state mode is the HEV mode and the target vehicle state mode is the EV mode, the engine stop sequence is processed.
Here, as shown in FIG. 7, the vehicle state mode includes an HEV mode, an EV mode, and an engine stop sequence mode and an engine start sequence mode, which are modes at the time of transition.
The HEV mode is a vehicle state mode in which the vehicle travels with at least the engine 1 as a drive source.

The mode of the engine stop sequence is a vehicle state mode at the time of transition when shifting from the HEV mode to the EV mode. The engine start sequence mode is a vehicle state mode at the time of transition from the EV mode to the HEV mode. When the current vehicle state mode and the target vehicle state mode are the same, the previous state mode is maintained.
For example, when the current vehicle state mode is the EV mode and the target vehicle state mode is also the EV mode, the vehicle state mode is set to the EV mode. Further, when the current vehicle state mode is the HEV mode and the target vehicle state mode is also the HEV mode, the vehicle state mode is set to the HEV mode.

On the other hand, when the current vehicle state mode is the EV mode and the target vehicle state mode is the HEV mode, or when the current vehicle state mode is the HEV mode and the target vehicle state mode is the EV mode, the transition mode is Until the engine 1 is stopped or started, the engine stop sequence mode or the engine start sequence mode is set.
As shown in FIG. 8, the vehicle state mode determination unit 21E in the present embodiment includes a cruise coast F / C determination processing unit 21Ea.

Hereinafter, the processing of the cruise coast F / C determination processing unit 21Ea will be described with reference to the flowchart of FIG.
First, in step S100, the above-described target drive torque and MG lower limit torque are acquired, and the process proceeds to step S110.
In step S110, it is determined whether the following conditional expression (1) is satisfied. And when conditional expression (1) is materialized, it transfers to step S120. On the other hand, if the conditional expression (1) is not satisfied, the process proceeds to step S130. In step S110, the conditional expression (1) is described as “condition [1]”.
MG lower limit torque <(target drive torque−F / C recovery determination value) (1)
Here, the above-mentioned “F / C recovery determination value” refers to the F / C that supplies fuel to the engine 1 again from the F / C state in which the fuel supply to the engine 1 is stopped to stop the engine 1. This is a threshold value used for determination of recovery.

The F / C recovery determination value is a preset value and is stored in the cruise coast F / C determination processing unit 21Ea. In addition to storing the F / C recovery determination value in the cruise coast F / C determination processing unit 21Ea, for example, a dedicated storage unit may be provided and acquired from this storage unit.
Further, when setting the F / C recovery determination value, the F / C recovery determination value may be set by changing the magnitude according to the set speed or the like in the automatic constant speed running.

In step S120, it is determined whether the target drive torque is equal to or greater than the F / C recovery determination value. If the target drive torque is equal to or greater than the F / C recovery determination value, the process proceeds to step S140. On the other hand, when the target drive torque is less than the F / C recovery determination value, the process proceeds to step S150.
In step S150, it is determined whether or not the target drive torque is less than the cruise coast F / C determination value. When the target drive torque is less than the cruise coast F / C determination value, the process proceeds to step S160. On the other hand, if the target drive torque is equal to or greater than the cruise coast F / C determination value, the process proceeds to step S170.

Here, the “cruise coast F / C determination value” is a threshold value used for determination of F / C for stopping the fuel supply to the engine 1 in order to stop the engine 1, and the F / C recovery determination value. Is a negative value. Specifically, it is a value corresponding to the negative target drive torque.
The cruise coast F / C determination value is a preset value, and is stored in the cruise coast F / C determination processing unit 21Ea. In addition to storing the cruise coast F / C determination value in the cruise coast F / C determination processing unit 21Ea, for example, a dedicated storage unit may be provided and acquired from this storage unit.

Further, when setting the cruise coast F / C determination value, the cruise coast F / C determination value may be set by changing the magnitude according to the set speed or the like in the automatic constant speed running.
In step S130, the cruise coast F / C prohibition request is set to “ON”, and the process proceeds to step S180.
In step S140, the cruise coast F / C prohibition request is set to “ON”, and the process proceeds to step S180.

In step S160, the cruise coast F / C prohibition request is set to “OFF”, and the process proceeds to step S180.
In step S170, the cruise coast F / C prohibition request is held at the previous value, that is, “ON” is set to “ON” in the previous process, and “OFF” is set to “OFF” in the previous process. "OFF" is set, and the process proceeds to step S180.
Here, the cruise coast F / C prohibition request is a command that is prioritized over the base control coast F / C determination described later, and has a function of invalidating the base control coast F / C determination.

In step S180, the base control coast F / C determination result is detected, and the process proceeds to step S190.
Here, the “base control coast F / C determination” is a determination as to whether or not the target drive torque is less than the “base control coast F / C determination value”. Specifically, when the target drive torque is less than the base control coast F / C determination value, the result of the base control coast F / C determination is set to “ON”. On the other hand, if the target drive torque is equal to or greater than the base control coast F / C determination value, the base control coast F / C determination result is set to “OFF”.

  The “base control coast F / C determination value” is an F / C that stops fuel supply to the engine 1 in order to stop the engine 1 during normal (base) travel that is not automatic constant speed travel. It is a threshold value used for determination. Specifically, the “base control coast F / C determination value” is different from the cruise coast F / C determination value, is higher than the F / C recovery determination value, and is a positive value, and is a positive target. It is a value corresponding to the driving torque.

The base control coast F / C determination value is a preset value and is stored in the cruise coast F / C determination processing unit 21Ea. In addition to storing the base control coast F / C determination value in the cruise coast F / C determination processing unit 21Ea, for example, a dedicated storage unit may be provided and acquired from this storage unit.
Further, when setting the base control coast F / C determination value, the base control coast F / C determination value may be set in accordance with the weight of the host vehicle.

  In step S190, the base control coast F / C determination result detected in step S180 and the cruise coast F / C prohibition request set in steps S130 to S170 are referred to. Further, in step S190, it is determined whether the result of the base control coast F / C determination is “ON” and whether the cruise coast F / C prohibition request is “OFF”.

When the result of the base control coast F / C determination is “ON” and the cruise coast F / C prohibition request is “OFF”, the process proceeds to step S200. On the other hand, if at least one of the base control coast F / C determination result is “ON” and the cruise coast F / C prohibition request is “OFF” is not established, The process proceeds to S210.
In step S200, the coast F / C request is set to “ON”, and the process proceeds to step S220.
In step S210, the coast F / C request is set to “OFF”, and the process proceeds to step S220.

  Here, the “coast F / C request” is a request corresponding to the result of the base control coast F / C determination and the cruise coast F / C prohibition request. This is the final command for performing / C. That is, if the coast F / C request is “ON”, the F / C is performed and the fuel supply to the engine 1 is stopped. If the coast F / C request is “OFF”, the fuel supply to the engine 1 is not performed without performing the F / C, or the fuel supply is again performed to the engine 1 in which the fuel supply is stopped. (F / C recovery).

In step S220, processing for operating the engine start control unit 21F and the engine stop control unit 21G is executed in response to the coast F / C request set in step S200 or step S210. Then return.
The target engine torque calculation unit 21H calculates the target engine torque based on the target vehicle state mode determined by the vehicle state mode determination unit 21E, travel state information such as vehicle speed, target drive torque, and requested engine torque required for power generation. calculate. Note that when the target vehicle state mode is the EV mode, the engine torque is not required, so the target engine torque is zero or a negative value. Further, when the preset F / C condition is satisfied, the engine 1 is in an idle state with the fuel supply stopped.

  The target motor torque calculation unit 21J calculates the target motor torque based on the target vehicle state mode determined by the vehicle state mode determination unit 21E, travel state information such as vehicle speed, target drive torque, and required power generation torque. For example, a value obtained by subtracting a torque value obtained by performing delay correction on the target engine torque from the target drive torque is set as the target motor torque. When there is an input of regenerative brake request torque (<0) from another control unit, a value obtained by adding the regenerative brake request torque is set as the final target motor torque.

The engine start control unit 21F operates when the engine start flag is ON, performs a process of starting the engine 1 while the motor is running, and performs a transition process to the HEV mode.
In addition, the engine start control unit 21F performs F / C recovery for the engine 1 in which the F / C is performed in response to the coast F / C request set by the cruise coast F / C determination processing unit 21Ea. Do. Specifically, when the coast F / C request is “ON” and the engine 1 is stopped, the fuel supply is stopped when the coast F / C request is shifted to the “OFF” state. By supplying fuel to the stopped engine 1, the stopped engine 1 is started.

Next, a processing example of the engine start control unit 21F will be described.
The engine start control unit 21F is activated when an engine start command (engine start flag is ON) is acquired during motor running.
First, a target second clutch torque command for setting the second clutch 5 to the target clutch transmission torque is output to the AT controller 24. The target second clutch transmission torque command TCL2 is a transmission torque command capable of transmitting a torque equivalent to the output torque before the engine starting process. Even if the driving force output from the motor 2 is increased, the target second clutch transmission torque command TCL2 affects the output shaft torque. The range that does not give Here, the AT controller 24 controls the second clutch hydraulic unit so that the clutch hydraulic pressure according to the command is generated.

  Next, a command for increasing the voltage of the motor 2 and controlling the rotational speed of the motor 2 is output to the motor controller 23. The actual torque of the motor 2 is determined by the load acting on the motor 2. Subsequently, a torque command is output to the AT controller 24 so that the torque transmission torque of the first clutch 4 becomes the cranking torque of the engine 1. Further, when it is detected that the engine speed and the motor speed are synchronized, a command for completely engaging the first clutch 4 is output as the end of the cranking process.

Specifically, the synchronization determination of the first clutch 4 determines that the first clutch 4 has been synchronized when a state where the differential rotation between the actual motor rotation and the actual engine rotation is equal to or less than a specified value has elapsed. Here, as the specified value, a differential rotation corresponding to the response dead time at the time of transition from the complete clutch to the fully engaged state is set. Further, when it is detected that the engine speed is equal to or higher than the startable speed, an engine start command is output to the engine controller 22. And it returns.
The engine stop control unit 21G is activated when an engine stop command (engine stop flag is ON) is acquired, drives the motor 2 from engine travel, and performs transition processing to motor travel.

  The engine stop control unit 21G performs the above F / C in response to the coast F / C request set by the cruise coast F / C determination processing unit 21Ea. Specifically, when the coast F / C request is “OFF” and the engine 1 is operating, the fuel to the engine 1 is shifted to a state where the coast F / C request is “ON”. By stopping the supply, the operating engine 1 is stopped.

  In addition, for example, the engine stop control unit 21G is activated when an engine stop command (engine stop flag is ON) is acquired, and first, a preset torque that causes the AT controller 24 to slide and engage the first clutch 4 is set. Outputs a command. Then, in synchronism with this torque command, a command to increase the voltage of the motor 2 and to control the rotational speed of the motor 2 is output to the motor controller 23.

  Thereby, the motor torque is increased while the torque from the engine 1 by the first clutch 4 is decreased, and the target drive torque is obtained. When the target motor torque becomes the target drive torque, a target first clutch 4 torque command for setting the first clutch 4 to target clutch transmission torque = 0 is output to the AT controller 24. Thereafter, a command for setting the target engine torque = 0 is output to the engine controller 22 to perform F / C.

  The target clutch torque calculation unit 21K calculates target clutch torques of the first clutch 4 and the second clutch 5 based on the target vehicle state mode determined by the vehicle state mode determination unit 21E and the torque generated by the engine 1 and the motor 2. . In the EV mode state, the first clutch 4 is output to the AT controller 24 and the second clutch 5 is output to the AT controller 24 to release the first clutch 4. In addition, the second clutch 5 is brought into an engaged state. Here, the engagement state of the second clutch 5 includes slip engagement.

In the HEV mode state, the first clutch 4 is output to the AT controller 24 and the second clutch 5 is output to the AT controller 24, whereby the first clutch 4 is engaged. In addition, the second clutch 5 is brought into an engaged state. Further, in the case of engine start or stop processing, the clutch torque that is in the above-described engaged / disengaged state is calculated.
Note that the VAPO calculation unit 21L in FIG. 3 calculates the corresponding estimated accelerator opening by performing reverse calculation from the above-described various cruise request torques, and uses the calculated estimated accelerator opening as the shift accelerator opening. 24.

(Function)
When control at constant speed traveling (cruise traveling), which is automatic traveling, is not being performed, the output of at least one of the engine 1 and the motor 2 that are driving sources is set with the driver requested torque based on the accelerator opening APO as the target driving force. Be controlled.
When the steering switch 28 is operated to start cruise traveling, a cruise target torque for setting the vehicle speed set by the driver is calculated as a target driving force. Furthermore, the output of at least one of the engine 1 and the motor 2 that are drive sources is controlled so that the calculated target drive torque is obtained. In this case, when the driver does not make a temporary acceleration request, the accelerator pedal 33 is in an OFF state, and only when the driver wants to accelerate temporarily, the driver depresses the accelerator pedal 33, The vehicle is temporarily accelerated.

In this way, the accelerator pedal 33 is normally kept OFF during cruise traveling in the automatic traveling state. For this reason, during cruise traveling, for example, when the road surface resistance changes on a small downhill slope or when the preceding vehicle is followed at a low speed, the traveling resistance decreases and the above-described target drive torque decreases. There is a case.
An example of a time chart at this time is shown in FIG. Here, the time chart shown in FIG. 10 shows a state in which the target drive torque is changing during cruise traveling.

As shown in FIG. 10, when the target drive torque decreases and becomes less than the positive base control coast F / C determination value (at time “t1”), the result of the base control coast F / C determination is “ The F / C request is made to the engine 1 by changing from “OFF” to “ON”.
At this time, since the target drive torque is equal to or greater than the negative cruise coast F / C determination value, the cruise coast F / C prohibition request is “ON” (see steps S150 and S170). That is, the above F / C is prohibited.
Here, the cruise coast F / C prohibition request has a function of invalidating the base control coast F / C determination as described above. In other words, even if the target drive torque is decreased, the coast F / C request is not “OFF” but remains “ON” in the state where the cruise coast F / C prohibition request is “ON” (step) (See S190 and S210).

When the target drive torque further decreases from the time t1 and becomes less than the cruise coast F / C determination value (at the time “t2”), the cruise coast F / C prohibition request is changed from “ON” to “OFF”. (See steps S150 and S160). That is, at time t2, the result of the base control coast F / C determination is “ON”, and the cruise coast F / C prohibition request is “OFF”.
Therefore, at time t2, the coast F / C request changes from “OFF” to “ON” (see Steps S190 and S200), and the final command for performing the F / C in the cruise traveling is “ ON ", and F / C for the engine 1 is performed.
At this time, in the case of a hybrid vehicle such as the above-described conventional example, the value corresponding to the coast F / C request is a value corresponding to the positive torque, so that the target drive torque to be reduced is frequently increased by the coast. It becomes less than the value corresponding to the F / C request. For this reason, F / C frequently occurs.

On the other hand, in this embodiment, since the cruise coast F / C determination value is a negative value, the target drive torque to be decreased is less than the cruise coast F / C determination value in a state where there is a reliable deceleration request. Become. For this reason, it becomes possible to give sufficient hysteresis to the conditions for generating the above F / C, and it is possible to suppress the frequent occurrence of F / C.
After the coast F / C request changes from “OFF” to “ON” at time t2, the cruise coast F / C prohibition request is as long as the target drive torque does not exceed the F / C recovery determination value. The previous value is held (see step S170). That is, after the coast F / C request changes from “OFF” to “ON” at time t2, the coast F / C request is “unless the target drive torque is equal to or greater than the F / C recovery determination value”. The F / C for the engine 1 is continued while being held “ON”.

  Then, when the coast F / C request is “ON” and the target drive torque increases and becomes equal to or greater than the F / C recovery determination value (at the time “t3”), the cruise coast F / C prohibition request becomes “ From “OFF” to “ON”. That is, at time t3, the result of the base control coast F / C determination is “ON”, and the cruise coast F / C prohibition request is “ON”.

Therefore, at time t3, the coast F / C request changes from “ON” to “OFF”, and the final command for performing the above F / C in the cruise traveling is “OFF”. F / C is prohibited and the above-described F / C recovery is performed.
At this time, in the case of a hybrid vehicle such as the conventional example described above, the value corresponding to the coast F / C request and the value corresponding to the F / C recovery determination value are the same value, so the increased target drive torque is Often, the value is equal to or greater than the value corresponding to the F / C recovery determination value. For this reason, F / C recovery frequently occurs.

  On the other hand, in the present embodiment, the F / C recovery determination value is a positive value larger than the cruise coast F / C determination value, which is a negative value. It is possible to provide sufficient hysteresis between the F / C determination value. For this reason, the target drive torque to be increased is equal to or higher than the F / C recovery determination value in a state where the operation of the engine 1 is surely required. Therefore, it is possible to give sufficient hysteresis to the above-described conditions for generating F / C recovery, and it is possible to suppress frequent occurrence of F / C recovery.

As a result, in the present embodiment, frequent occurrence of F / C and F / C recovery can be suppressed, and the start and stop of the engine 1 can be suppressed in a short time. It is possible to suppress a sense of discomfort given to the driver in automatic constant speed traveling such as.
When the target drive torque further increases from time t3 and becomes equal to or greater than the base control coast F / C determination value (time “t4”), the result of base control coast F / C determination is “OFF”. The fuel supply to the engine 1 is continued.

(Operation)
Hereinafter, the operation of the hybrid vehicle (own vehicle) including the vehicle travel control device of the present embodiment will be described with reference to FIGS. 1 to 10 and FIGS. 11 and 12.
FIG. 11 is a time chart showing the operation of the hybrid vehicle provided with the vehicle travel control device of the present embodiment.
As shown in FIG. 11, the target drive torque decreases when the host vehicle traveling on a cruise travels on a downhill slope. When the reduced target drive torque becomes less than the base control F / C determination value (at time “t5”), and further becomes less than the cruise coast F / C determination value (at time “t6”), the coast F / C. The request changes from “OFF” to “ON”.

Here, when the above-described conditional expression (1) is not satisfied, that is, when the MG lower limit torque is equal to or greater than (target drive torque-F / C recovery determination value), as shown in FIG. The coast F / C determination value is increased by considering the MG lower limit torque. In addition, FIG. 12 is a figure which shows the change of the cruise coast F / C determination value in consideration of the MG lower limit torque.
Here, the case where the above conditional expression (1) is not satisfied is a case where the required deceleration cannot be realized only by the regenerative torque generated by the regeneration of the motor 2 during deceleration during cruise traveling. This is a case where the electric power generated by the regeneration of the motor 2 exceeds the lower limit value of the power that can be input to the battery 9 when the required deceleration is obtained only by the regenerative torque generated by the motor 2 by the regeneration. It is.

Therefore, when the above conditional expression (1) is not satisfied, the cruise coast F / C determination value is increased by an amount corresponding to the MG lower limit torque as described above. Thereby, the timing at which F / C is performed is advanced, and the deceleration required at the time of deceleration in cruise traveling is obtained using the braking force (engine braking) due to the friction of the engine 1. At this time, the first clutch 4 is in an engaged state (including slip engagement).
As a result, even if the above conditional expression (1) is not satisfied, the battery 9 is prevented from being damaged, and the deceleration required during deceleration during cruise traveling is obtained to improve the maintainability of the vehicle speed. It becomes possible to make it.

When the coast F / C request becomes “ON” at time t6 and the above-described F / C is performed and the fuel supply to the engine 1 is stopped, the vehicle speed of the host vehicle is temporarily reduced and then increased. Return to the speed (constant speed) set in cruise driving.
After the coast F / C request becomes “ON” at time t6, when the target drive torque increases and becomes equal to or greater than the F / C recovery determination value (time “t7”), the coast F / C request becomes “ From “ON” to “OFF”, the above-described F / C recovery is performed.

As shown in FIG. 11, the F / C recovery determination value may be a negative value (a value less than 0 [Nm]) as long as it is larger than the cruise coast F / C determination value.
As described above, in this embodiment, the cruise coast F / C determination value is increased when the regenerative torque generated by the motor 2 is less than the torque corresponding to the target driving force.
Here, the automatic control required torque calculation unit 21Db constitutes an automatic travel means. Further, the steering switch 28 constitutes an operator that performs a starting operation by the driver.

(Effect of this embodiment)
(1) The automatic driving means is activated by a driver's starting operation and calculates a target driving force for automatically adjusting to a driving state set by the driver. Then, when the target driving torque corresponding to the target driving force becomes less than a negative cruise coast F / C determination value set in advance, a process of stopping fuel supply to the engine is performed. Here, the process of stopping the fuel supply to the engine is performed in a state where the driver's starting operation is detected and the engine is transmitting the driving force to the driving wheels and the vehicle is decelerating. .
For this reason, by setting the cruise coast F / C determination value to a negative value, the target drive torque to be reduced is less than the cruise coast F / C determination value in a state where there is a reliable deceleration request.

Further, since the F / C recovery determination value is a positive value larger than the cruise coast F / C determination value, which is a negative value, the F / C recovery determination value and the cruise coast F / C determination value It is possible to provide sufficient hysteresis between them.
For this reason, the increasing target drive torque is equal to or greater than the F / C recovery determination value in a state where the engine operation is surely required.

Therefore, it is possible to give sufficient hysteresis to the conditions for generating F / C, and to give sufficient hysteresis to the conditions for generating F / C recovery.
As a result, it is possible to suppress frequent occurrence of F / C and F / C recovery, and to suppress the start and stop of the engine in a short time. In automatic traveling such as cruise traveling, It is possible to suppress the uncomfortable feeling given to the driver.

(2) When the regenerative torque generated by the motor is less than the torque corresponding to the target driving force, the cruise coast F / C determination value is increased.
For this reason, at the time of deceleration in cruise traveling, even when the required deceleration cannot be achieved only by the motor regenerative torque, the timing for performing F / C is advanced and the engine brake is used during deceleration at cruise traveling. It is possible to obtain the required deceleration.
As a result, it is possible to prevent the battery from being damaged and to obtain the deceleration required at the time of deceleration during cruise traveling and to improve the maintenance of the vehicle speed, thereby improving the speed stability during cruise traveling. Is possible.

(Modification)
(1) In the present embodiment, the cruise coast F / C determination value is increased when the regenerative torque generated by the motor 2 is less than the torque corresponding to the target driving force, but the present invention is not limited to this. . That is, even if the regenerative torque generated by the motor 2 is less than the torque corresponding to the target driving force, the cruise coast F / C determination value need not be changed.

DESCRIPTION OF SYMBOLS 1 Engine 2 Motor 3 Automatic transmission 4 1st clutch 5 2nd clutch 7 Drive wheel 20 Acceleration sensor 21 Integrated controller 21A Required power generation torque calculation part 21B Request engine torque calculation part 21C Motor output possible torque calculation part 21D Target drive torque calculation part 21Da Driver required torque calculation unit 21Db Automatic control required torque calculation unit (automatic travel means)
21Dc First target drive torque calculation unit 21Dd Vehicle speed limiter torque calculation unit 21De Final target drive torque calculation unit 21E Vehicle state mode determination unit 21Ea Cruise coast F / C determination processing unit 21F Engine start control unit 21G Engine stop control unit 21H Target engine torque Calculation unit 21J Target motor torque calculation unit 21K Target clutch torque calculation unit 21L VAPO calculation unit 22 Engine controller 23 Motor controller 24 AT controller 25 Brake controller 26 Battery controller 28 Steering switch 30 Cruise cancel switch 31 Inter-vehicle control controller

Claims (2)

A vehicle travel control device that controls the travel of a hybrid vehicle including an engine and a motor as a drive source for transmitting a drive force to drive wheels,
An automatic traveling means that is activated by a driver's starting operation and calculates a target driving force for automatically adjusting to the traveling state set by the driver;
In the state in which the activation operation is detected and the engine transmits the driving force to the driving wheels and the hybrid vehicle is decelerating, a target driving torque corresponding to the target driving force is set in advance. A vehicle travel control device that stops fuel supply to the engine when the value becomes less than a cruise coast F / C determination value.   2. The vehicular travel control apparatus according to claim 1, wherein the cruise coast F / C determination value is increased when a regenerative torque generated by the motor is less than a torque corresponding to the target driving force.

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