JP7279308B2 - Vehicle control device and vehicle control method - Google Patents

Description

The present invention relates to a vehicle control device and a vehicle control method, and more particularly to steering assist technology.

Some vehicles, such as automobiles, are applied with steering assist technology for avoiding lane deviation as a kind of accident prevention technology. For example, Japanese Patent Laid-Open No. 2002-200001 discloses a technique for preventing a vehicle from departing from its lane by applying a steering force when the vehicle is about to depart from its lane.

In the technology disclosed in Patent Document 1, an on-vehicle camera detects a roadway line (division line) and a road edge, and the inside of the roadway line (lane side) is detected according to the width between the roadway line and the road edge. ) is set as the steering force application start position.

In the technology disclosed in Patent Document 1, when the vehicle approaches the outside line of the roadway, a steering force is applied to return the vehicle to the inside of the lane, thereby causing the vehicle to move toward the roadside from the outside line of the roadway. deviance can be suppressed.

JP 2017-174017 A

However, in the technique disclosed in Patent Document 1, when the vehicle approaches the outside line of the roadway, a constant steering force is applied irrespective of the vehicle speed without considering the running speed (vehicle speed) of the vehicle. As a result, the driver may feel annoyed or uncomfortable, and may be given a strong stress. In other words, even when the same steering force is applied, the driver feels different annoyance and discomfort between an urban area where the vehicle speed is relatively slow and an expressway where the vehicle speed is relatively fast.

For example, when driving on a highway at a high speed, the driver does not want to apply a very strong steering force. You will feel annoyance and discomfort.

The present invention is intended to solve the above-mentioned problems, and prevents accidents by suppressing deviations from the road regardless of the vehicle speed, while at the same time preventing the driver from feeling annoyed or uncomfortable. To provide a vehicle control device and a vehicle control method which are difficult to remember and stress.

A vehicle control device according to an aspect of the present invention is a vehicle control device that applies a steering force to the vehicle for suppressing the vehicle from deviating from a road according to a driving situation, the vehicle control device comprising : In the direction, the end portion that is the boundary between the lane in which the vehicle travels and the outside of the road is defined as a road edge, and the edge in the width direction of the lane is provided so as to extend along the road edge inside the road edge. When a line defining a section is defined as a marking line, a steering force generating section that generates the steering force to the vehicle, a marking line detecting section that detects the marking line , and a road edge detecting section that detects the road edge. and the vehicle speed detection unit for detecting the vehicle speed of the vehicle, the lane marking detection unit, the road edge detection unit, and the vehicle speed detection unit sequentially acquire detection results from the vehicle speed detection unit, and based on the acquired detection results, the steering a vehicle control unit that commands a force generation unit to apply the steering force to the vehicle, wherein the vehicle control unit applies a first steering force that is the steering force based on a first steering characteristic. and a second steering force greater than the first steering force based on a second steering characteristic different from the first steering characteristic. and a second steering force applying unit that commands the steering force generating unit to apply a second steering force applying unit that determines that the vehicle speed is within a predetermined speed range, and determines that the vehicle speed is within a predetermined speed range from the marking line to the road edge. The first steering force is applied to the vehicle when the side edge of the vehicle is positioned in the range to a predetermined point between the two, and the side edge of the vehicle is positioned in the range from the predetermined point to the road edge. the vehicle is positioned outside the predetermined speed range, and the vehicle is positioned within a range from the lane marking to the road edge. second steering control is executed to apply the first steering force to the vehicle if the

In the vehicle control device according to the above aspect, in the first steering control when the vehicle speed is within the predetermined speed range, the first steering force and the second steering force are applied by switching according to the position of the vehicle in the vehicle width direction. On the other hand, in the second steering control when the vehicle speed is outside the predetermined speed range , the first steering force is relatively small over the entire roadside strip. Therefore, in the vehicle control device according to the above aspect, when the vehicle speed is high, a large steering force (second steering force) is not applied. It is possible to suppress the person from feeling annoyance and discomfort.

Further, in the vehicle control device according to the aspect described above, when the vehicle deviates from the lane marking, the vehicle control unit selectively executes the first steering control or the second steering control to keep the vehicle in the lane. It is possible to return to Therefore, in the above aspect, it is possible to ensure safety while preventing the driver from feeling annoyed or uncomfortable.

Therefore, the vehicle control device according to the above aspect prevents accidents by suppressing deviation to the outside of the road regardless of the vehicle speed, while making it difficult for the driver to feel annoyed, uncomfortable, and stressed.

In the vehicle control device according to the aspect described above, when the vehicle control unit executes the first steering control, the second steering force applying unit relatively decreases the second steering force as the vehicle speed increases. It is also possible to instruct the steering force generation unit to do so.

In the vehicle control device employing the above configuration, even when the vehicle control unit executes the first steering control, instead of applying the second steering force based on the constant steering characteristic to the vehicle, the above steering force is applied according to the vehicle speed. Since the second steering force with varying strength of the steering force is applied to the vehicle as described above, it is possible to more reliably prevent the driver from feeling annoyed or uncomfortable.

In the vehicle control device according to the aspect described above, when the vehicle control unit executes the first steering control, the first steering force application unit controls the first steering characteristic based on the constant first steering characteristic regardless of the vehicle speed. It is also possible to instruct the steering force generator to apply a steering force of 1.

In the above vehicle control device, the first steering characteristic is a constant characteristic regardless of the vehicle speed, so the minimum steering force that is applied when the vehicle deviates from the lane marking is secured, and the safety of the vehicle is ensured. It is more suitable for

The vehicle control device according to the aspect described above further includes a driving environment detection unit that detects a driving environment of a lane in which the vehicle is traveling, wherein the vehicle control unit selectively selects between the first steering control and the second steering control. It is also possible to use the detection result from the driving environment detection unit when executing the above.

The vehicle control device selects between the first steering control and the second steering control using not only the actual vehicle speed of the own vehicle but also the running environment of the lane in which the own vehicle is running. Therefore, it is possible to ensure a higher level of safety while preventing the driver from feeling annoyed or uncomfortable.

In the vehicle control device according to the aspect described above, the driving environment detection unit may detect, as the driving environment, the speed limit of a speed limit sign installed for the lane.

Since the vehicle control device uses the speed limit read from the speed limit sign as an example of the driving environment, it is preferable from the viewpoint of ensuring safety.

A vehicle control method according to one aspect of the present invention is a vehicle control method for applying a steering force to the vehicle for suppressing the vehicle from deviating from a road according to a driving situation, the vehicle control method comprising : In the direction, the end portion that is the boundary between the lane in which the vehicle travels and the outside of the road is defined as a road edge, and the edge in the width direction of the lane is provided so as to extend along the road edge inside the road edge. When a line defining a section is defined as a lane marking, a lane marking detection step of detecting the lane marking; a road edge detection step of detecting the road edge; a vehicle speed detection step of detecting the vehicle speed of the vehicle; a steering force applying step capable of applying the steering force to the vehicle based on each detection result detected in the line detection step, the road edge detection step, and the vehicle speed detection step; are a first steering force applying substep of applying a first steering force that is the steering force based on the first steering characteristic; and a second steering characteristic that is different from the first steering characteristic. and a second steering force applying substep of applying a second steering force that is the steering force greater than the steering force, determining that the vehicle speed is within a predetermined speed range, determining that the vehicle speed is within a predetermined speed range, and determining that the vehicle speed is within a predetermined speed range from the lane marking to the road edge. The first steering force is applied to the vehicle when the side edge of the vehicle is positioned in the range up to a predetermined point between a first steering control that applies the second steering force to the vehicle if the vehicle is positioned, determines that the vehicle speed is outside the predetermined speed range, and determines that the vehicle is within a range from the lane marking to the road edge; A second steering control is executed to apply the first steering force to the vehicle when the vehicle is positioned.

In the vehicle control method according to the above aspect, in the first steering control when the vehicle speed is within the predetermined speed range, the first steering force and the second steering force are applied by switching according to the position of the vehicle in the vehicle width direction. On the other hand, in the second steering control when the vehicle speed is outside the predetermined speed range , the first steering force is relatively small over the entire roadside strip. Therefore, in the vehicle control method according to the above aspect, a large steering force (second steering force) is not applied when the vehicle speed is high. It is possible to suppress the person from feeling annoyance and discomfort.

Further, in the vehicle control method according to the aspect described above, when the vehicle deviates from the lane marking, the vehicle control unit selectively executes the first steering control or the second steering control to keep the vehicle in the lane. It is possible to return to Therefore, in the above aspect, it is possible to ensure safety while preventing the driver from feeling annoyed or uncomfortable.

Therefore, in the vehicle control method according to the aspect described above, by suppressing the deviation to the outside regardless of the vehicle speed, an accident is prevented, and the driver is less likely to feel annoyed or uncomfortable, and is less likely to be stressed.

In the vehicle control method according to the aspect described above, when the first steering control is executed in the steering force application step, the second steering force in the second steering force application sub-step is relatively increased as the vehicle speed increases. can also be reduced to

In the vehicle control method described above, even when the vehicle control unit executes the first steering control, instead of applying the second steering force based on the constant steering characteristic to the vehicle, the steering force is applied according to the vehicle speed as described above. Since the second steering force whose strength changes is applied to the vehicle, it is possible to more reliably prevent the driver from feeling annoyed or uncomfortable.

In the vehicle control method according to the above aspect, when the first steering control is executed in the steering force applying step, the first steering force in the first steering force applying sub-step is set to the constant steering force regardless of the vehicle speed. It can also be set based on the first steering characteristic.

In the above vehicle control method, since the first steering characteristic is a constant characteristic regardless of the vehicle speed, the minimum steering force to be applied when the vehicle deviates from the lane marking is secured, and the safety of the vehicle is ensured. It is more suitable for

The vehicle control method according to the aspect described above further includes a driving environment detection step of detecting a driving environment of a lane in which the vehicle travels, wherein the steering force applying step selects between the first steering control and the second steering control. It is also possible to use the result related to the driving environment detected in the driving environment detection step when executing the method.

In the above vehicle control method, not only the actual vehicle speed of the own vehicle but also the detection results regarding the driving environment of the lane in which the own vehicle is traveling are used to select the first steering control or the second steering control. Since it is supposed to be performed, even higher safety can be ensured while suppressing the driver's feeling of annoyance and discomfort.

In the vehicle control method according to the aspect described above, in the driving environment detection step, the speed limit of a speed limit sign installed for the lane may be detected as the driving environment.

In the vehicle control method described above, the speed limit read from the speed limit sign is used as an example of the driving environment, which is preferable from the viewpoint of ensuring safety.

In each of the above modes, by suppressing the deviation to the outside regardless of the vehicle speed, an accident is prevented, and the driver is less likely to feel annoyed or uncomfortable, and is less likely to be stressed.

1 is a schematic diagram showing a schematic configuration of a vehicle according to an embodiment; FIG. FIG. 2 is a block diagram showing the control configuration of the vehicle; FIG. FIG. 4 is a schematic diagram for explaining the detection of lane markings and road edges by an exterior camera; 4 is a flowchart showing a steering control method executed by a control unit; FIG. 5 is a schematic diagram showing the relationship between the positions of lane markings and roadsides and the applied steering torque when the first steering control mode is set; FIG. 9 is a schematic diagram showing the relationship between the positions of lane markings and roadsides and the applied steering torque when the second steering control mode is set; (a) is a schematic diagram showing a state in which a vehicle crosses a lane marking and begins to deviate into a roadside strip, and (b) is a schematic diagram showing a state in which the vehicle further deviates from the roadside strip toward the road edge. It is a diagram. 7 is a flowchart showing a method of setting a second steering torque value when the control unit executes the first steering control mode; 4 is a schematic diagram showing a reference table stored in a table storage unit; FIG. FIG. 5 is a schematic diagram showing a second steering torque value that is set according to the vehicle speed of the host vehicle; 9 is a flowchart showing a method of setting a second steering torque value when the control unit executes a first steering control mode in steering control according to a modification;

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described, considering drawing into consideration. In addition, the form described below is an example of the present invention, and the present invention is not limited to the following forms except for its essential configuration.

In the drawings used in the following description, "Fr" is the front of the vehicle (direction of travel), "Re" is the rear of the vehicle, "Le" is the left of the vehicle, and "Ri" is the right of the vehicle. direction.

[Embodiment]
1. Schematic Configuration of Vehicle 1 A schematic configuration of a vehicle 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG.

As shown in FIG. 1, a vehicle 1 has an engine 2 as a power source. In the vehicle 1 according to this embodiment, a multi-cylinder gasoline engine is used as an example of the engine 2 .

A transmission 3 is connected to the engine 2 , and a differential gear 4 is connected to the transmission 3 . A drive shaft 5 extends laterally from the differential gear 4 . Left and right front wheels 6 l and 6 r are attached to the ends of the drive shaft 5 .

The drive shaft 5 is provided with a left front brake 7l at a portion near the left front wheel 6l and a right front brake 7r at a portion near the right front wheel 6r.

Left and right rear wheels 8 l and 8 r are arranged behind the vehicle 1 . The left and right rear wheels 8l and 8r are attached to rear arms (not shown). A shaft (not shown) that supports the left rear wheel 8l is provided with a left rear brake 9l, and a shaft (not shown) that supports the right rear wheel 8r is provided with a right rear brake 9r. there is

As shown in FIG. 1 , a steering handle 10 is arranged in front of the driver's seat in the passenger compartment of the vehicle 1 . The steering handle 10 is attached to the tip portion of the steering shaft 11 . The other end of steering shaft 11 is connected to steering gear 12 . A steering actuator 14 is connected to the steering shaft 11 so that steering torque (steering force) can be applied to the steering shaft 11 . That is, in the vehicle 1, the steering actuator 14 functions as a steering force generator that generates steering force.

A tie rod 13 is connected to the steering gear 12 . As the tie rod 13 moves left and right, the directions of the front wheels 6l and 6r are changed.

As shown in FIG. 1 , the vehicle 1 is provided with three radars 15 , 16 , 17 and an exterior camera (imaging device) 18 . Of the three radars 15 , 16 , 17 , the radar 15 is arranged on the front part of the vehicle 1 and the remaining two radars 16 , 17 are arranged on the sides of the vehicle 1 . These radars 15, 16, and 17 have functions of detecting vehicles around the own vehicle (vehicle 1), and detecting relative speeds and relative distances between the vehicle 1 and the surrounding vehicles.

The vehicle exterior camera 18 detects lane markings and roadsides in front of the vehicle 1, and also detects signs provided for the lane in which the vehicle 1 travels. That is, in the vehicle 1 according to the present embodiment, the lane marking detection unit (roadway outside line detection unit, roadway center line detection unit) that detects the lane markings (roadway outside line, roadway center line, etc.) on both sides of the traveling lane There is a road edge detection unit that detects a road edge located on the road outside of the lane marking, and a driving environment detection unit that detects the driving environment including the sign.

The vehicle 1 is also provided with a map information storage unit 19 . The map information storage unit 19 stores information about roads on which the vehicle 1 travels. The map information stored in the map information storage unit 19 also includes lane information on roads.

Note that the map information storage unit 19 may have a function of communicating with an external server. It is also possible to configure so that information can be acquired.

In addition, the vehicle 1 is provided with an alarm device 20 capable of issuing an alarm to a passenger on board.

A vehicle speed sensor 21 for detecting the vehicle speed of the vehicle 1 is connected to the output shaft (not shown) of the transmission 3 of the vehicle 1 . That is, in the vehicle 1, the vehicle speed sensor 21 is a vehicle speed detector.

The vehicle 1 is also provided with a control unit (vehicle control section) 22 . The control unit 22 comprises a microprocessor comprising a CPU, a ROM, a RAM, etc., and as shown in FIGS. It is connected to the information storage unit 19, the vehicle speed sensor 21, etc., and is configured to receive various types of information.

Based on the received information, the control unit 22 can issue commands to the engine 2, the steering actuator 14, the alarm device 20, and the brakes 7l, 7r, 9l, 9r.

Furthermore, as shown in FIG. , and a driving environment determination unit 224 . These will be described later.

2. Detection of lane markings DL _L , _DLR , road edge E _RL , and sign 500 by exterior camera 18 Detection of lane markings DL _L , _DLR , road edge E _RL , and sign 500 by exterior camera 18 is shown in FIG. will be used for explanation. FIG. 3 is a schematic diagram for explaining the detection of the lane markings DL _L and DL _R , the roadside E _RL and the sign 500 by the vehicle exterior camera 18 .

As shown in FIG. 3 , the vehicle exterior camera 18 provided on the interior side of the front windshield of the vehicle 1 can detect a range θ ₁₈ on the front side of the vehicle 1 .

Here, in the present embodiment, as an example, the vehicle 1 is traveling on the left lane LN. A left lane marking (roadway outer line) DL _L is provided on the left side of the lane LN, and a right lane marking (roadway center line) DL _R is provided on the right side of the lane LN. A roadside _ERL exists on the left side of the roadway outside line _DLL .

The vehicle exterior camera 18 can detect at least the roadway outer line DL _L , the roadway center line DL _R , and the road edge E _RL . In the detection of the roadway outer line _DLL and the roadway center line _DLR by the vehicle exterior camera 18, the outer ends _EDLL and _EDLR of the lane markings _DLL and _DLR can also be detected.

The road edge E _RL is the boundary between the roadside strip on the left side (outside) of the roadway outside line _DLL and the road outside OR. Various types of roadside _ERL are stored in the control unit 22 according to road conditions. , road edge E _RL .

In addition, the exterior camera 18 can also detect a roadside strip or a sign 500 provided outside the road. FIG. 3 shows a speed limit sign 500 as an example.

3. Steering Control by Control Unit 22 Steering control by the control unit 22 will be described with reference to FIGS. 4 to 7. FIG. FIG. 4 is a _{flow chart showing the steering control executed by the control unit 22, and FIG .} FIG. 6 is a schematic diagram showing the relationship between the steering torque and the steering torque, and FIG. 6 shows the relationship between the positions of the lane markings _DLL and the road edge _ERL and the applied steering torque when the second steering control mode is set. FIG. 7A is a schematic diagram showing a state in which the vehicle 1 crosses the roadway outside line _DLL and begins to deviate toward the road edge _ERL ; FIG. (b) is a schematic diagram showing a state in which the vehicle 1 has deviated further from the side strip toward the road edge _ERL .

As shown in FIG. 4, the control unit 22 acquires the detection results from the vehicle exterior camera 18 (detection results of the roadway outer line DL _L , the roadway center line DL _R , the road edge E _RL , and the sign 500) ( step S1). The control unit 22 determines whether or not the vehicle speed V of the own vehicle 1 is within a predetermined speed range (V _TH1 to V _TH2 ) based on the acquired detection results (step S2).

Here, in the present embodiment, 100 km/h is set as an example of the speed V _TH1 , and 60 km/h is set as an example of the speed V _TH2 . These velocities V _TH1 and V _TH2 are values stored in advance in the control unit 22 .

Returning to FIG. 4, when the control unit 22 determines in step S2 that the vehicle speed V is within the predetermined speed range (V _TH1 to V _TH2 ) (step S2: Yes), the first steering control mode is set for the steering actuator 14 (step S3).

On the other hand, when the control unit 22 determines in step S2 that the vehicle speed V is not within the predetermined speed range (V _TH1 to V _TH2 ) (step S2: No), the second steering control mode is set to the steering actuator. 14 (step S4).

(i) First steering control mode As shown in FIG. 5, the first steering control mode set by the control unit 22 for the steering actuator 14 includes steering torque (steering force) based on the first steering characteristic CH1, 2 Prepare to apply a steering torque (steering force) based on the steering characteristic CH2 to the vehicle 1, and as shown in _FIG . When the _DLL begins to deviate from the left lane marking line outer edge E _DLL , the steering torque ST1 based on the first steering characteristic CH1 is applied, and as shown in FIG. In this mode, the steering torque ST2 based on the second steering characteristic CH2 is applied when the E _VCL deviates further to the outside (road edge E _RL ) from the left lane marking line outer edge E _DLL of the roadway outer line _DLL .

In the above description, it is the first steering torque applying section 221 of the control unit 22 that commands the steering actuator 14 to apply the steering torque ST1 based on the first steering characteristic CH1, and the steering torque based on the second steering characteristic CH2. It is the second steering torque applying section 222 of the control unit 22 that commands the application of ST2.

Returning to FIG. 5, the first steering characteristic CH1 is set with the steering torque corresponding to the position in the direction toward the road edge _ERL with the left lane marking line outer edge _EDLL of the roadway outer line _DLL as a base point. characteristics. Specifically, the first steering characteristic CH1 includes a torque increase portion (steering force increase portion) L1 that gradually increases to the first steering torque value TO1 in the range from the left side marking line outer end _EDLL to the point P2, and a torque increase portion (steering force increase portion) L1 that gradually increases from the point P2 to the point P2. (Characteristic switching point) In the range up to P1, there is a torque maintaining portion L2 in which the first steering torque value TO1 is maintained.

The second steering characteristic CH2 is a characteristic in which the steering torque is set corresponding to the position in the direction toward the road edge _ERL with the point P3 as the base point. Specifically, the second steering characteristic CH2 includes a torque increase portion (steering force increase portion) L3 that gradually increases to the second steering torque value TO2 in the range from the point P3 to the road edge _ERL , and a torque increase portion (steering force increase portion) _L3 that and a torque maintaining section L4 in which the second steering torque value TO2 is maintained in the range of (off-road OR).

As shown in FIG. 5, in the present embodiment, as an example, the slope of the torque increase portion L3 in the second steering characteristic CH2 is set substantially the same as the slope of the torque increase portion L1 in the first steering characteristic CH1. It is

In addition, since the first steering characteristic CH1 and the second steering characteristic CH2 overlap in the range from the point P3 to the characteristic switching point P1, the steering torque based on the second steering characteristic CH2 is actually applied. This is the range from the characteristic switching point P1 to the road edge _ERL .

(ii) Second steering control mode As shown in FIG. 6, in the second steering control mode set by the control unit 22 for the steering actuator 14, only the steering torque (steering force) based on the first steering characteristic CH1 is applied to the vehicle. 1, and as shown in FIG. 7(a), when the vehicle left edge _EVCL of vehicle 1 begins to deviate from the left lane outer edge E _DLL of the roadway outside line _DLL as indicated by arrow A. In this mode, the steering torque ST1 based on the first steering characteristic CH1 is applied and the application of the steering torque ST1 is maintained until the left side edge _EVCL of the vehicle 1 reaches the road edge _ERL .

Returning to FIG. 6, the first steering characteristic CH1 in the second steering control mode is also the same as the first steering control characteristic in the first steering control mode.

4. Setting the second steering torque value TO2 according to the vehicle speed V The control unit 22 of the vehicle 1 according to the present embodiment sets the second steering torque value TO2 according to the vehicle speed V of the host vehicle 1 when the first steering control mode is selected. It is assumed that the value TO2 is variable. This will be described with reference to FIGS. 8 to 10. FIG. FIG. 8 is a flowchart showing a method of setting the second steering torque value TO2 when the control unit 22 executes the first steering control mode, and FIG. FIG. 10 is a schematic diagram showing a second steering torque value TO2 that is set according to the vehicle speed V of the host vehicle 1. FIG.

As shown in FIG. 8, when the first steering control mode is selected, the control unit 22 first acquires the detection result (vehicle speed data of the own vehicle 1) from the vehicle speed sensor 21 (step S11). In this case, since the first steering control mode is selected, the vehicle speed V is within the predetermined speed range (V _TH1 to V _TH2 ).

Then, the control unit 22 refers to the reference table Tab stored in the table storage section 223, and sets the second steering torque value TO2 according to the vehicle speed V (step S12). As shown in FIG. 9, in the reference table Tab, second steering torque values TO2x (TO2 ₁ to TO2 ₂₂ ) are associated with vehicle speeds V (velocities V _TH1 to V _TH2 ).

Here, the velocities V _TH1 to V _TH2 and the second steering torque values TO2 ₁ to TO2 ₂₂ respectively satisfy the following relationships.

V _TH1 >V ₁ >V ₂ >...>V ₁₉ >V ₂₀ >V _TH2 (Equation 1)
TO2 ₁ <TO2 ₂ <TO2 ₃ <... <TO2 ₂₀ <TO2 ₂₁ <TO2 ₂₂ (Equation 2)
FIG. 10 shows the relationship between (Equation 1) and (Equation 2) above. That is, as shown in FIG. 10, the faster the vehicle speed V of the host vehicle 1, the smaller the second steering torque value TO2 is set. Conversely, the slower the vehicle speed V of the host vehicle 1, the larger the second steering torque value TO2 is set. be done.

As shown in FIG. 10, in the steering control of the vehicle 1 according to the present embodiment, when the control unit 22 selects and executes the first steering control mode, the first steering characteristic CH1 is related to the vehicle speed V and the like. constant characteristics are maintained.

In the steering control of the vehicle 1 having the configuration as described above, the vehicle 1 is prevented from causing an accident by suppressing the deviation to the off-road OR regardless of the magnitude of the vehicle speed V. It's hard to let go, and it's hard to stress.

[Modification]
A steering control method for the vehicle 1 according to the modification will be described with reference to FIG. 11 . FIG. 11 is a flowchart showing a method of setting the second steering torque value TO2 when the control unit 22 executes the first steering control mode in the steering control according to the modification. The steering control method according to this modification is the same as the steering control method according to the above-described embodiment, except for the method of setting the second steering torque value TO2.

As shown in FIG. 11, in the steering control according to this modified example, when the control unit 22 selects the first steering control mode, the detection result from the vehicle exterior camera 18 and the map information from the map information storage unit 19 and are obtained (step S21). Here, in the steering control according to the present modification, the driving environment determination unit 224 extracts the speed limit sign 500 from the imaging data of the vehicle exterior camera 18, and determines the speed limit of the lane in which the vehicle 1 is traveling. Read from the map information storage unit 19 .

Then, the driving environment determining section 224 of the control unit 22 determines the driving environment (speed limit) from the acquired information on the speed limit (step S22). In addition to the vehicle speed V of the own vehicle 1, the control unit 22 sets the second steering torque value TO2 after considering the driving environment (speed limit) determined by the driving environment determination unit 224 (step S23).

For example, the control unit 22 temporarily sets the second steering torque value TO2 from the reference table Tab based on the vehicle speed V of the host vehicle 1, and then sets the second steering torque value TO2 based on the driving environment (speed limit). correct. The second steering torque value TO2 is corrected, for example, by increasing the second steering torque value TO2 as the speed displayed on the speed limit sign 500 increases, and decreasing the displayed speed. 2 Correct the steering torque value TO2 so that it becomes smaller. This is because roads with high speed limits generally have wide lane widths and roadside strip widths, while roads with low speed limits tend to have narrow lane widths and roadside strip widths.

The control unit 22 of the vehicle 1 according to the present modification, which executes the steering control as described above, suppresses the deviation to the off-road OR regardless of the magnitude of the vehicle speed V, thereby preventing an accident from occurring and giving the driver a command. It is difficult to further remember the annoyance and discomfort of facing, and it is difficult to stress.

[Other Modifications]
In the above embodiment and modification, the second steering torque value TO2 is set when the control unit 22 selects the first steering control mode by referring to the reference table Tab stored in the table storage section 223. However, the present invention is not limited to this. For example, based on the detected vehicle speed V, the second steering torque value may be calculated sequentially.

Further, in the above embodiment, when the left side edge _EVCL of the vehicle approaches the road edge _ERL , the vehicle speed is reduced and an alarm is issued, but these are not essential. Alternatively, only one of the deceleration of the vehicle speed and the issuance of an alarm may be performed.

Further, in the above-described embodiment and modified example, the second steering characteristic CH2 also has the torque maintaining portion L4, but this is also not essential. For example, when the left side of the vehicle contacts or exceeds the road edge, the vehicle may be stopped without applying the steering torque.

In addition, when the left end of the vehicle approaches the road edge, the warning device 20 is instructed to issue an alarm, and the engine 2 and the brakes 7l, 7r, 9l, 9r are controlled by the vehicle. It is also possible to issue a command to decelerate the vehicle speed.

Further, in the above-described embodiment and modified example, the engine 2 is used as the power source of the vehicle 1, but the present invention is not limited to this. For example, it is also applicable when an electric motor is used as a drive source.

Further, in the above-described embodiment and modified example, it is assumed that the vehicle 1 is traveling in the left lane LN, but the present invention is not limited to this. For example, it can also be applied to the case of right-hand traffic. In this case, the first steering control and the second steering control can be selected based on the width of the side strip between the right lane marking and the road edge further to the right.

In addition, in the above modified example, as an example of the driving environment, the information about the vehicle speed extracted from the speed limit sign 500 provided in the lane in which the vehicle 1 is driving is adopted. is not limited to For example, obstacles, pedestrian crossings, and even railroad crossings in front of the vehicle can be detected as the driving environment related to the vehicle speed of the vehicle.

Further, in the above-described embodiment and modification, the range of 60 km/h to 100 km/h is adopted as an example of the "predetermined speed range", but the present invention is not limited to this. For example, the lower limit of the predetermined speed range can be set to a value within the range of 10 km/h to 50 km/h, and the upper limit can be set to a value within the range of 120 km/h to 200 km/h. It can be set in consideration of the vehicle type and the road environment of the destination.

1 Vehicle 14 Steering Actuator (Steering Force Generation Unit)
18 Vehicle exterior camera (laning line detection unit, road edge detection unit, driving environment detection unit)
21 vehicle speed sensor (vehicle speed detector)
22 Control unit (vehicle control unit)
221 First steering torque applying section 222 Second steering torque applying section 223 Table storage section 224 Driving environment determining section 500 Speed limit sign CH1 First steering characteristic CH2 Second steering characteristic DL _L lane (roadway outside line)
DL _R division line (roadway center line)
E _RL road edge E _VCL vehicle left edge (vehicle side edge)
LN lane (lane)
OR off road

Claims (10)

A vehicle control device that applies a steering force to the vehicle for suppressing the vehicle from deviating from the road according to the driving situation,
In the left-right direction of the vehicle, the edge portion that is the boundary between the lane in which the vehicle travels and the outside of the road is defined as a road edge, and is provided so as to extend along the road edge inside the road edge and in the lane When the line that defines the end in the width direction is the division line,
a steering force generator that generates the steering force to the vehicle;
a marking line detection unit that detects the marking line;
a road edge detection unit that detects the road edge;
a vehicle speed detection unit that detects the vehicle speed of the vehicle;
The detection results from the lane marking detection section, the road edge detection section, and the vehicle speed detection section are sequentially acquired, and based on the acquired detection results, the steering force generation section instructs the steering force generation section to apply the steering force to the vehicle. a vehicle control unit that commands the application;
with
The vehicle control unit
a first steering force applying unit that commands the steering force generating unit to apply a first steering force that is the steering force based on the first steering characteristic;
Applying a second steering force for instructing the steering force generator to apply a second steering force that is the steering force greater than the first steering force, based on a second steering characteristic different from the first steering characteristic. Department and
has
When it is determined that the vehicle speed is within a predetermined speed range, and the side edge of the vehicle is positioned within a range from the lane marking to a predetermined point between the lane marking and the road edge, the first steering force is applied. executing a first steering control that applies the second steering force to the vehicle and applies the second steering force to the vehicle when the side edge of the vehicle is positioned within a range from the predetermined location to the road edge;
determining that the vehicle speed is outside the predetermined speed range, and executing a second steering control that applies the first steering force to the vehicle when the vehicle is positioned within a range from the lane marking to the road edge;
Vehicle controller. The vehicle control device according to claim 1,
When the vehicle control unit executes the first steering control, the second steering force applying unit relatively decreases the second steering force as the vehicle speed increases. command to
Vehicle controller . The vehicle control device according to claim 1 or 2,
When the vehicle control unit executes the first steering control, the first steering force application unit applies the first steering force based on the constant first steering characteristic regardless of the vehicle speed. command the steering force generator ,
Vehicle controller . The vehicle control device according to any one of claims 1 to 3,
Further comprising a driving environment detection unit that detects the driving environment of the lane on which the vehicle travels,
The vehicle control unit also uses a detection result from the driving environment detection unit when selectively executing the first steering control and the second steering control .
Vehicle controller . In the vehicle control device according to claim 4,
The driving environment detection unit detects the speed limit of the speed limit sign installed for the lane as the driving environment. A vehicle control method for applying a steering force to the vehicle for suppressing the vehicle from deviating from the road according to the driving situation,
In the left-right direction of the vehicle, the edge portion that is the boundary between the lane in which the vehicle travels and the outside of the road is defined as a road edge, and is provided so as to extend along the road edge inside the road edge and in the lane When the line that defines the end in the width direction is the division line,
a marking line detection step of detecting the marking line;
a road edge detection step of detecting the road edge;
a vehicle speed detection step of detecting the vehicle speed of the vehicle;
a steering force applying step capable of applying the steering force to the vehicle based on each detection result detected in the lane marking detection step, the road edge detection step, and the vehicle speed detection step;
with
The steering force application step includes:
a first steering force applying substep of applying a first steering force that is the steering force based on the first steering characteristic;
a second steering force applying substep of applying a second steering force, which is the steering force greater than the first steering force, based on a second steering characteristic different from the first steering characteristic;
has
When it is determined that the vehicle speed is within a predetermined speed range, and the side edge of the vehicle is positioned within a range from the lane marking to a predetermined point between the lane marking and the road edge, the first steering force is applied. executing a first steering control that applies the second steering force to the vehicle and applies the second steering force to the vehicle when the side edge of the vehicle is positioned within a range from the predetermined location to the road edge;
determining that the vehicle speed is outside the predetermined speed range, and executing a second steering control that applies the first steering force to the vehicle when the vehicle is positioned within a range from the lane marking to the road edge;
Vehicle control method. A vehicle control method according to claim 6,
when the first steering control is executed in the steering force application step, the second steering force in the second steering force application sub-step is made relatively smaller as the vehicle speed increases ;
Vehicle control method . A vehicle control method according to claim 6 or claim 7,
setting the first steering force in the first steering force applying sub-step based on the first steering characteristic that is constant regardless of the vehicle speed when the first steering control is executed in the steering force applying step ;
Vehicle control method . The vehicle control method according to any one of claims 6 to 8,
Further comprising a driving environment detection step of detecting the driving environment of the lane on which the vehicle travels,
In the steering force applying step, when selectively executing the first steering control and the second steering control, the results related to the driving environment detected in the driving environment detecting step are also used .
Vehicle control method . A vehicle control method according to claim 9,
In the driving environment detection step, the speed limit of a speed limit sign installed for the lane is detected as the driving environment .
Vehicle control method .

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