JP6884999B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device for controlling a vehicle during cruise control.

A cruise control device has been developed that enables a vehicle to run while maintaining a constant vehicle speed.

In addition to the conventional cruise control function, Adaptive Cruise Control (ACC) also controls the vehicle speed according to the movement of the vehicle in front. As shown in Patent Document 1, during ACC, the distance to the vehicle in front is measured by a radar, a camera, or the like, and the follow-up running is performed while maintaining the distance.

In the ACC control, the target acceleration is set according to the distance to the vehicle in front and the set vehicle speed. For example, when the distance to the vehicle in front is approached, the engine brake is activated to set the target acceleration to a negative acceleration. As a result, the vehicle is controlled to maintain a distance from the vehicle in front.

Japanese Unexamined Patent Publication No. 9-323628

However, for example, when the vehicle is traveling downhill, even if the engine brake is activated and the target acceleration is set to a negative acceleration, the vehicle accelerates above the set vehicle speed, and the engine brake alone is sufficient for the vehicle in front. The distance may be too close.

At this time, in addition to the engine brake, the vehicle is controlled by applying the brake by the friction braking force using the braking part such as the disc brake or the drum brake on the wheel, but the brake by the friction braking force continues to be applied for a long time. , There is a problem that the burden on the braking part becomes large.

In the automatic mode of the automatic transmission, the automatic adjustment of the downshift by the transmission means is activated, so that the above problem does not occur. However, in the manual mode of the automatic transmission, the driver must execute the downshift by himself / herself. However, the above problem becomes prominent.

The present invention has been made in view of this point, and an object of the present invention is to provide a vehicle control device capable of reducing a burden on a braking unit that applies frictional braking force to wheels in a manual mode of an automatic transmission.

In the vehicle control device according to the present invention, the braking unit that applies frictional braking force to the wheels and the automatic transmission are set to the manual mode, and the friction braking force is applied to the wheels by the braking unit based on the target vehicle speed or the target vehicle-to-vehicle distance. There are added, the the Rutoki product exceeds the threshold value of the liquid pressure application value indicated operation time and the braking portion of the brake unit, the control unit automatically performs the downshift of the automatic transmission And, characterized by having.

According to this configuration, when braking intervention by friction braking force continues for a long time during cruise control, the load on the braking part is reduced by automatically executing the downshift of the automatic transmission in the manual mode. Can be done. In addition, by determining the frictional braking force applied to the wheels in consideration of the operating time of the braking unit, the frictional braking force that is the reference for downshifting can be appropriately determined, and as a result, the burden on the braking unit is effective. Can be mitigated .

Alternatively, in the vehicle control device according to the present invention, the braking unit that applies frictional braking force to the wheels and the automatic transmission are set to the manual mode, and the braking unit rubs against the wheels based on the target vehicle speed or the target vehicle-to-vehicle distance. braking force and is added to the Rutoki product exceeds the threshold value of the liquid pressure application value indicated in the braking unit and the operating time of the braking portion, and a control unit for determining the downshift of the automatic transmission The control unit has an instruction unit for instructing the driver to downshift the automatic transmission based on the determination of the control unit, and the control unit instructs the driver to downshift the automatic transmission by the instruction unit. It is characterized in that the downshift is automatically executed for the automatic transmission when the downshift by the manual operation is not executed even after a lapse of a predetermined time.

According to this configuration, when braking intervention by frictional braking force continues for a long time during cruise control, a downshift instruction is displayed or announced on the instruction unit during manual operation in order to reduce the burden on the braking unit. Therefore, the driver can be encouraged to downshift. In addition, by determining the frictional braking force applied to the wheels in consideration of the operating time of the braking unit, the frictional braking force that is the reference for downshifting can be appropriately determined, and as a result, the burden on the braking unit is effective. Can be mitigated .

It is a conceptual diagram which shows the vehicle including the vehicle control device which concerns on this embodiment. It is a flowchart which shows the downshift control routine which used the vehicle control device which concerns on this embodiment. It is a flowchart which shows the establishment condition of the downshift.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the vehicle control device 2 according to the present embodiment is mounted on the vehicle 1. The vehicle control device 2 shown in FIG. 1 is equipped with an adaptive cruise control (hereinafter referred to as ACC) device. During ACC, when the vehicle in front of the vehicle 1 is not captured, the vehicle maintains the traveling at the preset vehicle speed, and when the vehicle in front is captured in the front, the distance between the vehicle and the vehicle in front is maintained. Is controlled. Note that FIG. 1 describes a vehicle 1 provided with an automatic transmission 14.

The vehicle control device 2 includes a braking unit 4 that applies a braking force to the wheels 3, and a control unit 5 that includes an ACC controller 6, a downshift determination unit 7, an engine control controller 8, and a brake control controller 9. It is composed. The vehicle control device 2 shown in FIG. 1 is further configured to include an operation unit 16 and a display unit 15. The vehicle control device 2 of the present embodiment may have a configuration in which the display unit 15 or the operation unit 16, or the display unit 15 and the operation unit 16 are not provided.

The braking portion 4 is provided on each wheel 3. The braking unit 4 is a device for applying a braking force due to friction to each wheel 3, and includes, for example, a disc brake or a drum brake. Although not limited, each brake will be described below as a hydraulic braking device.

As shown in FIG. 1, the braking unit 4 is electrically connected to the brake control controller 9 of the control unit 5. Then, the brake control controller 9 instructs the braking unit 4 to add a hydraulic pressure, whereby a predetermined friction braking force acts on the wheels 3.

The ACC controller 6 shown in FIG. 1 controls when following a vehicle in front. The ACC controller 6 has a camera radar 10 that measures the distance to the vehicle in front, a sensor 11 that detects the vehicle speed and engine speed, and a setting switch 12 that can set the set vehicle speed and the distance to the vehicle in front. Etc. are connected.

The camera radar 10 photographs the vehicle in front from behind, and the ACC controller 6 calculates the distance to the vehicle in front based on the image obtained by this imaging.

The sensor 11 is a vehicle speed sensor, an engine speed sensor, an accelerator opening sensor, or the like, and the sensor value is sent to the electrically connected ACC controller 6.

The setting switch 12 constitutes an ACC on / off switch, a target vehicle speed setting switch, a target vehicle-to-vehicle distance setting switch, and the like, and each switch information is transmitted to the ACC controller 6 electrically connected to the setting switch 12.

In this way, the vehicle speed, engine speed information, target vehicle speed, target vehicle-to-vehicle distance, and the like are input to the ACC controller 6. Then, the ACC controller 6 calculates the target acceleration and the required engine torque from the measured distance information with the vehicle in front.

The downshift determination unit 7 determines whether or not to downshift the automatic transmission 14 based on the friction braking force applied to the wheels 3.

The engine control controller 8 controls the engine 13 in accordance with the request from the ACC controller 6. That is, the required engine torque information calculated by the ACC controller 6 is transmitted to the engine control controller 8, and the engine throttle instruction value is transmitted to the electronic throttle device (not shown) based on the required engine torque. Then, the throttle opening degree is adjusted by the electronic throttle device, and the output of the engine 13 is controlled.

The brake control controller 9 controls the brake in accordance with the request from the ACC controller 6. That is, the target acceleration information calculated by the ACC controller 6 is transmitted to the brake control controller 9, and the brake control controller 9 applies a predetermined friction braking force from the braking unit 4 to the wheels 3 based on the target acceleration. Instruct. In this embodiment, as described above, the brake control controller 9 instructs the braking unit 4 of the hydraulic pressure addition value, whereby a predetermined friction braking force is applied to the wheels 3.

As shown in FIG. 1, the brake control controller 9 executes a downshift of the automatic transmission 14 when the friction braking force applied to the wheels 3 satisfies a predetermined condition in the manual mode of the automatic transmission 14. .. Although the "predetermined condition" is not particularly limited, it is preferable to set the condition in consideration of the operating time of the braking unit 4. The "execution of downshifting of the automatic transmission 14" refers to a state in which the driver automatically downshifts the automatic transmission 14 instead of manually downshifting. The same applies hereinafter.

As described above, in the manual mode of the automatic transmission 14, when the friction braking force applied to the wheels 3 satisfies a predetermined condition, the brake control controller 9 automatically executes the downshift of the automatic transmission 14. .. As a result, the engine brake based on the downshift acts, and the vehicle 1 is decelerated and controlled to reach the target vehicle speed or the target vehicle-to-vehicle distance.

The vehicle control device 2 of the embodiment shown in FIG. 1 includes a display unit 15 as an instruction unit electrically connected to the brake control controller 9. The display unit 15 is a device capable of displaying a display prompting the driver to shift gears. In the manual mode of the automatic transmission 14, when the friction braking force applied to the wheels 3 satisfies a predetermined condition, a downshift instruction can be displayed on the display unit 15 to encourage the driver to downshift. ..

Here, in the configuration in which the brake control controller 9 automatically executes the downshift to the automatic transmission 14, the display unit 15 for displaying the downshift instruction may not be provided. Further, in the configuration provided with the display unit 15 for displaying the downshift instruction, the brake control controller 9 does not automatically control the automatic transmission 14 to execute the downshift. Good. However, the configuration may include both the downshift execution to the automatic transmission 14 and the downshift display instruction to the display unit 15. For example, a downshift instruction is displayed on the display unit 15, but if the driver does not execute the downshift even after a predetermined time has elapsed, the automatic transmission 14 is automatically downshifted. It may be configured.

Further, in the vehicle control device 2 of the embodiment shown in FIG. 1, an operation unit 16 is provided so that the driver can switch between the automatic mode and the manual mode of the automatic transmission 14. In the auto mode, the gear ratio is automatically set based on the driving conditions such as the vehicle speed and the accelerator opening. On the other hand, in the manual mode, the driver manually selects the gear ratio. The operation information of the operation unit 16 is transmitted to the control unit 5. The operation information of the operation unit 16 is sent to the ACC controller 6, the brake control controller 9, and the like.

During ACC, when the automatic transmission 14 is set to the manual mode, the downshift determination unit 7 determines whether or not the friction braking force applied to the wheels 3 satisfies a predetermined condition. When in ACC and the automatic transmission 14 is in auto mode, the existing cruise control is executed. In this way, by using the operation information related to the mode switching from the operation unit 16, it is possible to quickly and accurately control the downshift in the control unit 5 in the manual mode of the automatic transmission 14.

For example, during ACC, the vehicle 1 in which the automatic transmission 14 is set to the manual mode travels downhill, and at this time, a friction braking force is applied to the wheels 3 based on the target vehicle speed or the target vehicle-to-vehicle distance. At that time, in the vehicle control device 2 of the present embodiment, downshift control to the automatic transmission 14 is performed by satisfying a predetermined condition. The downshift control routine using the vehicle control device 2 shown in FIG. 1 will be described below.

In step ST1 shown in FIG. 2, whether or not the automatic transmission 14 is set to the manual mode is determined by the control unit 5 based on the operation signal from the operation unit 16 shown in FIG. Whether the automatic transmission 14 is in the manual mode or the automatic mode can be determined by the downshift determination unit 7 or the ACC controller 6 if the ACC controller 6 is operating. However, the determination that the automatic transmission 14 is in the manual mode may be made by a controller other than the downshift determination unit 7 or the ACC controller 6. When the automatic transmission 14 is in the auto mode, the downshift control routine shown in FIG. 2 is not executed. When the automatic transmission 14 is in the auto mode during ACC, the existing cruise control is executed.

Next, when the automatic transmission 14 is set to the manual mode, it is determined in step ST2 whether or not ACC is in progress. When the ACC switch of the setting switch 12 is turned on, the ACC controller 6 operates, so that it can be determined that ACC is in progress. If not in ACC, the downshift control routine shown in FIG. 2 is not executed.

In this way, when the control unit 5 determines that the automatic transmission 14 is in the manual mode and is in the ACC, the downshift determination unit 7 subsequently performs a downshift with respect to the automatic transmission 14. Decide whether to execute. The downshift execution condition can be determined based on, for example, the flow shown in FIG.

That is, as shown in step ST5 shown in FIG. 3, for example, the downshift determination unit 7 determines whether or not the product of the brake operating time and the required hydraulic pressure exceeds a predetermined value (hereinafter, referred to as a threshold value). Here, the "required hydraulic pressure" is a hydraulic pressure addition value instructed by the brake control controller 9 to the braking unit 4 based on the target acceleration calculated by the ACC controller 6. The threshold value is set by multiplying the brake operating time to which the hydraulic pressure addition value is applied by the above-mentioned hydraulic pressure addition value. The brake operating time can be obtained from the brake control controller 9 by the indicated time of the hydraulic pressure added value to the braking unit 4. Information on the indicated time (operating time) is sent to the downshift determination unit 7. The threshold value can be arbitrarily determined based on the friction braking force applied to the wheel 3. The threshold value is stored in a storage unit (not shown), and the downshift determination unit 7 can obtain threshold information from the storage unit. Then, the downshift determination unit 7 determines whether or not the product of the hydraulic pressure added value instructed by the brake control controller 9 to the braking unit 4 and the brake operation time exceeds the threshold value.

As described above, in the present embodiment, not only the hydraulic pressure addition value but also the brake operation time is taken into consideration to determine the friction braking force applied to the wheel 3. That is, it is a condition that the brake operating time is equal to or longer than a predetermined time with respect to the hydraulic pressure added value. As described above, the reason why the brake operating time is added as the threshold value is that the frictional braking force applied to the wheel 3 cannot be accurately determined only by the hydraulic pressure addition value. For example, if the threshold value is set only by the hydraulic pressure addition value, the downshift determination unit 7 does not execute the downshift when the hydraulic pressure addition value is lower than the threshold value. However, even if the hydraulic pressure addition value is low, the longer the brake operating time, the larger the brake load on the wheel 3. Therefore, the frictional braking force, which is the reference for downshifting, can be appropriately determined by taking into account the braking operation time.

For example, the vehicle 1 in which the automatic transmission 14 is set to the manual mode is traveling downhill during ACC, and the brake control controller 9 sends the braking unit 4 to the predetermined hydraulic pressure of the hydraulic braking device. Is added. Then, in the vehicle control device 2 of the present embodiment, the downshift determination unit 7 calculates the product of the hydraulic pressure addition value and the brake operation time, and whether or not the product exceeds a preset threshold value. To judge.

When the product of the brake operating time and the hydraulic pressure added value exceeds the threshold value, the downshift execution condition for the automatic transmission 14 is satisfied as shown in step ST6 of FIG.

When the downshift execution condition for the automatic transmission 14 is satisfied in this way, the downshift to the automatic transmission 14 is executed as shown in step ST4 shown in FIG. At this time, as shown in FIG. 1, the downshift execution signal is transmitted from the brake control controller 9 to the automatic transmission 14 to downshift the automatic transmission 14.

When the shift lever is located at "D (drive)", for example, the brake control controller 9 automatically downshifts the shift lever of the automatic transmission 14 to "2 (second)". As a result, the engine brake associated with the downshift is applied to control the vehicle to return to the target vehicle speed or the target vehicle-to-vehicle distance. At this time, the brake control controller 9 reduces the load on the braking unit 4 by releasing the frictional braking force applied to the wheel 3 or reducing the frictional braking force applied to the wheel 3. can do.

2 and 3, the configuration for executing the downshift of the automatic transmission 14 has been described, but the configuration for displaying the downshift instruction on the display unit 15 shown in FIG. 1 will be described below. Even when the downshift instruction is displayed on the display unit 15, there is no change in steps ST1 to ST3 in FIG. 2 and steps ST5 and ST6 in FIG.

That is, during ACC, when the automatic transmission 14 is in the manual mode, when the product of the brake operating time and the hydraulic pressure added value exceeds the threshold value, the downshift instruction display condition to the display unit 15 is satisfied. To do.

Then, in step ST4 shown in FIG. 2, a downshift instruction display is executed on the display unit 15. At this time, as shown in FIG. 1, the downshift instruction display signal is transmitted from the brake control controller 9 to the display unit 15, and the display unit 15 displays the downshift instruction. The driver sees the downshift instruction displayed on the display unit 15 and manually executes the downshift.

For example, when the shift lever is located at "D (drive)" and instructs "2 (second)" to downshift, the display of "2" on the instrument panel as the display unit 15 blinks. For example, the driver can be prompted to give a downshift instruction. In addition to blinking, the display method can be changed in color and size, and can be accompanied by voice information.

According to the above configuration, for example, when braking intervention continues for a long time during ACC and there is concern about fading or wear of the braking unit 4, a downshift is executed during manual operation to move the braking unit 4 to the braking unit 4. The burden can be reduced. As a result, fading and the like can be avoided.

Further, for the downshift instruction display to the display unit 15, for example, when the gear shift indicator is mounted on the vehicle, the display unit 15 is added again by making the gear shift indicator function as the display unit 15 of the present embodiment. You don't have to. Therefore, it is possible to suppress the cost increase.

Further, in FIG. 1, the brake control controller 9 executes the downshift of the automatic transmission 14, or the display unit 15 is instructed to display the downshift, but it is also possible to execute the downshift from another controller. ..

The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the configuration of the block diagram shown in FIG. 1 and the steps of the flowchart shown in FIGS. 2 and 3 are not limited to this, and may be appropriately changed within the range in which the effects of the present invention are exhibited. It is possible. In addition, it can be appropriately modified and implemented as long as it does not deviate from the scope of the object of the present invention.

For example, in the block diagram shown in FIG. 1, a voice unit may be used instead of the display unit. That is, the downshift instruction voice signal is transmitted from the brake control controller 9 to the voice unit, and the downshift instruction is announced by the voice unit. The driver listens to the announcement of the downshift instruction and manually executes the downshift.

Further, it is also possible to make the downshift determination function in the ACC controller 6, for example, without individually providing the downshift determination unit 7 in the control unit 5. At this time, in the ACC controller 6, it is determined whether or not the product of the hydraulic pressure added value and the brake operating time exceeds the threshold value.

As described above, the present invention is useful as a vehicle control device during manual driving during cruise control.

1 Vehicle 2 Vehicle control device 3 Wheels 4 Braking unit 5 Control unit 6 ACC controller 7 Downshift judgment unit 8 Engine control controller 9 Brake control controller 10 Camera radar 11 Sensor 12 Setting switch 13 Engine 14 Automatic transmission 15 Display unit 16 Operation unit

Claims (2)

A braking part that applies frictional braking force to the wheels,
The automatic transmission is set to the manual mode, and a frictional braking force is applied to the wheels by the braking unit based on the target vehicle speed or the target vehicle-to-vehicle distance, and the operating time of the braking unit and the liquid instructed by the braking unit. to exceed the threshold value the product of the pressure application value Rutoki, and a control unit for executing downshift automatically the automatic transmission,
A vehicle control device characterized by having. A braking part that applies frictional braking force to the wheels,
The automatic transmission is set to the manual mode, and a frictional braking force is applied to the wheels by the braking unit based on the target vehicle speed or the target vehicle-to-vehicle distance, and the operating time of the braking unit and the liquid instructed by the braking unit. a control unit for the product of the pressure application value in Rutoki exceeds a threshold value, determines the downshift of the automatic transmission,
Based on the judgment of the control unit, an instruction unit that instructs the driver to downshift the automatic transmission, and an instruction unit.
Have,
The control unit automatically downshifts the automatic transmission when the downshift by manual operation is not executed even after a predetermined time has elapsed after the instruction unit instructs the downshift of the automatic transmission. A vehicle control device characterized by performing a shift.

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