JP2006007836A - Lane deviation preventive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform lane deviation preventive control without imparting a sense of incompatibility to a driver. <P>SOLUTION: When a direction indicating switch 20 is in an OFF state, the existence of intervention of steering is determined (Step S11); the existence of operation of the direction indicating switch 20 of the past is determined (Step S12); the existence of return steering operation of the past is determined (Step S13); and the existence of an adjacent traffic lane is determined (Step S14). Thus, when there is a tendency of a deviation, the direction indicating switch 20 has been operated lately, and the return steering operation has been performed, the lane deviation preventive control is performed with the yaw moment reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lane departure prevention apparatus for preventing a departure when a host vehicle is about to depart from a traveling lane during traveling.

Conventionally, as such a lane departure prevention device, for example, it is determined that the host vehicle is likely to deviate from the traveling lane, and each wheel is controlled according to the lateral deviation of the traveling position of the host vehicle with respect to the reference position of the traveling lane. There is one that controls the driving force and generates a yaw moment in the vehicle by combining the control in the yaw direction and the deceleration control, thereby preventing deviation from the traveling lane and preventing the passenger from feeling uncomfortable (for example, Patent Document 1). reference).
JP 2003-111540 A

In the technique disclosed in Patent Literature 1, when the direction indicator is operated in the departure direction, it is assumed that the driver intends to change the lane and the lane departure prevention control is not intervened.
However, the direction indicator may be canceled despite the driver's intention to change lanes. For example, if the driver stops steering while turning the steering wheel while turning on the direction indicator, or if the steering is returned by a small amount, the direction indicator may be canceled depending on the rotational position of the steering. is there. Also, some drivers change lanes after turning on the turn signal and turning it off immediately (that is, after blinking the turn signal only once). In this case, as long as there is a tendency to deviate as a rule, the lane departure prevention control intervenes, which makes the driver trying to change the lane feel uncomfortable.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a lane departure prevention apparatus that performs lane departure prevention control without causing a driver to feel uncomfortable.

A lane departure prevention apparatus according to the present invention includes a departure determination unit that determines that the host vehicle tends to deviate from the traveling lane, a direction indicator operation detection unit that detects an operation of the direction indicator, and the direction indicator. When it is determined that the storage means for storing the operation history and the deviation determination means tend to deviate, and the direction indicator operation detection means detects the turn-on operation of the direction indicator, the direction indicator And a departure prevention control intervention means for intervening departure prevention control based on the indicated direction and the direction of the departure tendency.
The lane departure prevention device is configured to prevent the departure prevention control contents to be intervened by the departure prevention control intervention means based on the operation history of the direction indicator stored in the storage means when the direction indicator is in an off state. The contents are changed by means of changing contents.

  According to the present invention, since the departure prevention control content is changed based on the operation history of the direction indicator, it is possible to intervene in the lane departure prevention control in consideration of the driver's intention to change the lane.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a vehicle illustrating an example of a lane departure prevention apparatus according to the present embodiment. This vehicle is a rear wheel drive vehicle equipped with an automatic transmission and a conventional differential gear, and the braking device can control the braking force of the left and right wheels independently of the front and rear wheels.

  In the figure, reference numeral 1 is a brake pedal, 2 is a booster, 3 is a master cylinder, and 4 is a reservoir. Normally, the brake fluid pressure boosted by the master cylinder 3 depends on the amount of depression of the brake pedal 1 by the driver. The brake fluid pressure control circuit 7 is interposed between the master cylinder 3 and the wheel cylinders 6FL to 6RR, while being supplied to the wheel cylinders 6FL to 6RR of the wheels 5FL to 5RR. In the braking fluid pressure control circuit 7, the braking fluid pressures of the wheel cylinders 6FL to 6RR can be individually controlled.

  The brake fluid pressure control circuit 7 uses a brake fluid pressure control circuit used for, for example, anti-skid control and traction control. In this embodiment, the brake fluid pressure of each wheel cylinder 6FL-6RR is increased or decreased independently. It is comprised so that it can press. The brake fluid pressure control circuit 7 controls the brake fluid pressures of the wheel cylinders 6FL to 6RR in accordance with a brake fluid pressure command value from a vehicle state control unit 8 described later.

  Further, this vehicle is provided with a CCD camera 13 and a camera controller 14 as a front external environment recognition sensor for detecting the position of the host vehicle in the traveling lane for determination of preventing the departure of the traveling lane of the host vehicle. The camera controller 14 detects, for example, a lane marker such as a white line from a captured image in front of the host vehicle captured by the CCD camera 13 to detect a travel lane, and also the yaw angle φ of the host vehicle with respect to the travel lane, that is, the lane The direction of the host vehicle, the lateral displacement X of the host vehicle from the center of the traveling lane, the curvature β of the traveling lane, and the like can be calculated.

  The camera controller 14 performs travel lane detection using a travel lane detection area for detecting a lane marker or the like, and calculates each data for the detected travel lane. For example, a technique described in Japanese Patent Application Laid-Open No. 11-296660 can be used for detecting the traveling lane. Specifically, lane markers such as white lines on both sides of the traveling lane in which the host vehicle is traveling are detected, and the traveling lane in which the host vehicle is traveling is detected using the lane marker. Here, if a lane marker such as a white line is detected (scanned) over the entire captured image, the calculation load is large and time is required. Therefore, a smaller detection area (so-called window) is set in an area where a lane marker is likely to exist, and the lane marker is detected within the detection area. Generally, when the direction of the host vehicle with respect to the lane changes, the position of the lane marker displayed in the image also changes. For example, in Japanese Patent Application Laid-Open No. 11-296660, the direction of the host vehicle with respect to the lane is estimated from the steering angle δ. The detection area is set in the area where the lane marker of the above will be displayed. Then, for example, a filtering process that makes the boundary between the lane marker and the road surface stand out is performed, a straight line that seems to be the boundary between the lane marker and the road surface is detected in each lane marker detection region, and one point (lane marker candidate point) on the straight line is detected as the lane marker. It is detected as a representative site. If the lane marker candidate points of each window obtained in this way are continued, it is possible to detect a traveling lane that is deployed ahead of the host vehicle.

Further, this vehicle is equipped with a navigation system 10 suitable for guiding the host vehicle. The navigation system 10 detects the longitudinal acceleration Xg and lateral acceleration Yg generated in the host vehicle, and the yaw rate φ ′ generated in the host vehicle, in addition to the position information, road information, map information, and the like of the host vehicle using a so-called GPS function. It has a function. The road information, longitudinal acceleration Xg, lateral acceleration Yg, and yaw rate φ ′ detected by the navigation system 10 are output to the vehicle state control unit 8. In addition, the vehicle includes a steering angle sensor 19 that detects the steering angle δ of the steering wheel 21 and a wheel speed sensor 22FL that detects a rotation speed of each wheel 5FL to 5RR, that is, a so-called wheel speed Vw _i (i = FL to RR). -22RR, a direction indicating switch 20 for detecting a direction indicating operation by the direction indicator is provided, and these detection signals are also output to the vehicle state control unit 8. Further, the yaw angle φ of the host vehicle with respect to the traveling lane detected by the camera controller 14, the lateral displacement X of the host vehicle from the center of the traveling lane, the curvature β of the traveling lane, and the engine driving torque controlled by the engine control unit Tw is also output to the vehicle state control unit 8 together. If the detected vehicle traveling state data has left and right directions, the left direction is the positive direction. That is, the yaw rate φ ′, the lateral acceleration Yg, the steering angle δ, and the yaw angle φ are positive values when turning left, and the lateral displacement X is a positive value when deviating from the center of the traveling lane to the left.

  Next, the logic of the arithmetic processing performed by the vehicle state control unit 8 will be described according to the flowchart of FIG. This calculation process is executed by a timer interruption every predetermined sampling time ΔT every 10 msec., For example. In this flowchart, no communication step is provided, but information obtained by the arithmetic processing is updated and stored in the storage device as needed, and necessary information is read out from the storage device as needed.

In this calculation process, first, in step S1, various data from each sensor, controller, and control unit are read. Specifically, the longitudinal acceleration Xg, the lateral acceleration Yg, the yaw rate φ ′ detected by the navigation system 10, the wheel speeds Vw _i detected by the sensors, the steering angle δ, the direction indication switch signal, and the camera controller 14. The yaw angle φ of the host vehicle with respect to the travel lane, the lateral displacement X of the host vehicle from the center of the travel lane, the curvature β of the travel lane, and the drive torque Tw from the engine control unit are read.

In step S2 Subsequently, the among the wheel speeds Vw _i I read in step S1, before a non-driven wheel left and right wheel speeds Vw _FL, calculates the traveling velocity V of the vehicle from an average value of Vw _FR. When the vehicle is a front wheel drive vehicle, the host vehicle travel speed V is calculated from the average value of the rear left and right wheel speeds Vw _RL and Vw _RR that are non-drive wheels.
Further, when the estimated vehicle speed is calculated by the anti-skid control device, the value may be used as the host vehicle traveling speed. Further, the traveling speed of the host vehicle used in the navigation system 10 may be used. Further, the traveling speed may be compared using the traveling speed of the host vehicle obtained from the transmission output shaft speed.

Subsequently, in step S3, a departure from the traveling lane of the host vehicle is determined. In the present embodiment, first, a future estimated lateral displacement XS is calculated as a deviation estimated value. Specifically, the yaw angle φ with respect to the traveling lane of the own vehicle read in step S1, the lateral displacement X of the own vehicle from the center of the traveling lane, the curvature β of the traveling lane, and the traveling speed of the own vehicle calculated in step S2. V is used to calculate a future estimated lateral displacement XS according to the following equation (2).
XS = Tt × V × (φ + Tt × V × β) + X (2)

Here, Tt is the vehicle head time for calculating the forward gaze distance, and when the vehicle head time Tt is multiplied by the traveling speed V of the host vehicle, the front gaze distance is obtained. That is, the estimated lateral displacement from the center of the traveling lane after the vehicle head time Tt becomes the estimated lateral displacement XS in the future. Then, the absolute value of future estimated lateral displacement as the deviation estimate | XS | when is lateral displacement limit value X _C or higher, and the departure flag F _LD for example, to be in a departure tendency vehicle from the traffic lane Otherwise, it is determined that the host vehicle does not tend to deviate from the traveling lane, for example, the departure determination flag _FLD is reset to “0”.

Subsequently, in step S4, a lane change of the host vehicle is determined. Specifically, the direction of the direction indicating switch signal read in step S1, the lateral displacement X of the host vehicle from the center of the traveling lane, or the estimated future lateral displacement XS as the deviation estimated value calculated in step S3. When the departure direction obtained from the above is the same, the departure determination flag _FLD is forcibly reset to “0” because it is a conscious lane change. On the other hand, if the direction of the direction indicating switch signal is different from the lateral displacement X or the departure direction, the departure determination flag _FLD is forcibly maintained at “1” because there is a possibility of departure. Therefore, as long as the processing is such, when the direction indicating switch 20 is not operated, the departure determination flag _FLD becomes “1” as long as there is a departure tendency.

Here, the direction indicator switch 20 being operated means that the direction indicator is being operated by the driver. Further, the departure determination flag _FLD is a flag for determining the intervention of the lane prevention control. In this step S4, when the direction indicating switch 20 is turned on, the direction of the direction indicating switch 20 (indicated direction) ) And the direction of departure tendency, the intervention for departure prevention control is determined.

Here, when the direction indicating switch 20 is not operated, the driver's intention to change lanes is determined. FIG. 3 is a flowchart showing the processing procedure of the processing.
First, in step S11, the presence or absence of steering intervention is determined. Specifically, the steering angle δ read in step S1 is compared with first and second set values (threshold values) Δδ ₁ and Δδ ₂ (Δδ ₁ > Δδ ₂ ) set in advance, and The presence or absence of steering intervention is determined based on the comparison result. FIG. 4 is a flowchart showing the processing procedure of the processing.

First, in step S21, it compares the steering angle δ and the first set value .DELTA..delta _1. If the steering angle δ is greater than or equal to the first set value Δδ ₁ (δ ≧ Δδ ₁ ), it is determined that the driver intends to change the lane, and the process proceeds to step S23, where the departure determination flag _{FLD is set} to “0”. Change to "". Then, the process of step S11 ends (proceeds to step S12). When the steering angle δ is less than the first set value Δδ ₁ (δ <Δδ ₁ ), the process proceeds to step S22.

In step S22, it compares the steering angle δ and the second set value .DELTA..delta _2. If the steering angle δ is greater than or equal to the second set value Δδ ₂ (δ ≧ Δδ ₂ ), the process proceeds to step S24, and the steering determination flag F _{str is set} to “1”. Then, the process of step S11 ends (proceeds to step S12). When the steering angle δ is less than the second set value Δδ ₂ (δ <Δδ ₂ ), the process proceeds to step S25, and the steering determination flag F _{str is set} to “0”. Then, the process of step S11 ends (proceeds to step S12).

The steering intervention determination as described above is performed in step S11.
Subsequently, in step S12, it is determined whether or not the past (most recent) direction switch 20 has been operated. FIG. 5 is a flowchart showing the processing procedure of the processing.
First, in step S31, it is determined whether or not the past direction indicating switch 20 has been operated. Specifically, the presence / absence of operation of the direction indicating switch 20 is determined from the history of the direction indicating switch signal read in step S1 within the latest predetermined period Δt.

FIG. 6A shows an example of a history of direction indication switch signals corresponding to the left and right operation directions of the direction indication switch 20. As shown in FIG. 6A, a direction indication switch signal can be detected in accordance with the operation direction of the direction indication switch 20.
FIG. 6B shows an example of a change in the steering angle δ. As shown in FIG. 6B, the return steering operation cancels the operation of the direction indicating switch 20, so that the direction indicating switch signal is also turned off as shown in FIG. 6A.

  In step S31, it is determined whether or not the direction indicating switch 20 is operated by looking at the change in the predetermined period Δt for the direction indicating switch signal changing in this way. Note that the predetermined period Δt is, for example, 1 second. Note that the operation history of the direction indicating switch 20 in the predetermined period Δt is stored in the storage device in the vehicle state controller 8 as needed, and the history data is updated.

Here, when it is determined from the history of the direction indicating switch signal within the predetermined period Δt that the direction indicating switch 20 is operated (that the direction indicating switch signal is detected), the process proceeds to step S32 and the direction indicating switch operation is performed. A flag (hereinafter simply referred to as a switch operation flag) F _{sw_turn} is _set to “1”. Then, the process of step S12 ends (proceed to the process of step S13). On the other hand, if it is determined from the history of the direction indicating switch signal within the predetermined period Δt that the direction indicating switch 20 is not operated (the direction indicating switch signal is not detected), the process proceeds to step S33 and the switch operation flag is set. _Set F _{sw_turn} to “0”. And the process of step S4 is complete | finished, without progressing to the process of step S13 (it progresses to the process of step S5).

The operation determination of the direction indicating switch 20 as described above is performed in step S12.
In step S13, it is determined whether or not there is a past (most recent) return steering operation. FIG. 7 is a flowchart showing the processing procedure of the processing.
First, in step S41, it is determined whether a return steering operation is being performed. Specifically, the return steering operation is determined from the history of the steering torque within the latest predetermined period Δt. As shown in FIG. 6B, the operating angle δ changes due to the return steering operation, but the value of the steering torque within the most recent predetermined period Δt is the opposite value, that is, from a positive value to a negative value, or negative When the value changes from positive to positive, it is determined that the return steering operation is being performed. When the return steering operation is performed, the process proceeds to step S42, and when the return steering operation is not performed, the process proceeds to step S43.

In step S42, the return steering determination flag F _{str_return} is _set to “1”, and further the lane change intention flag F _{relane_change} is _set to “1”. That is, when the lane change intention flag F _{relane_change} is “1”, this indicates that the vehicle has returned to the travel lane in the past to change the lane once. And the process of step S4 is complete | finished (it progresses to the process of step S5).
In step S43, the return steering determination flag F _{str_return} is _set to “0”. Then, the process proceeds to step S14.
The steering operation determination as described above is performed in step S13.
In step S14, it is determined whether there is an adjacent lane. FIG. 8 is a flowchart showing the processing procedure of the processing.

First, in step S51, it is determined whether there is an adjacent lane. Specifically, it is determined whether there is an adjacent lane based on the current travel lane information and the lane number information of the host vehicle obtained as road information from the navigation system 10. If there is an adjacent lane, the process proceeds to step S52. If there is no adjacent lane, the process proceeds to step S53, the adjacent lane flag F _{next is set} to “0”, and the process of step S14 is terminated (process of step S5). Go to).

In step S52, the adjacent lane flag F _{next is set} to “1”, and the process proceeds to step S54. In step S54, it is determined whether or not the steering determination flag _Fstr obtained in step S11 is "0". If the steering determination flag F _str is “0” (δ <Δδ ₂ ), the process proceeds to step S55. In step S55, the lane change intention flag F (relane_change) is set to “1”. Then, the process of step S14 ends (proceeds to step S5). If the steering determination flag F _str is not “0” (δ ≧ Δδ ₂ ), the process of step S14 ends (proceeds to step S5).

The adjacent lane determination as described above is performed in step S14, and the process in step S4 is terminated.
In step S4, _various flags including a departure determination flag F _LD , a switch operation flag F _{sw_turn} return steering determination flag F _{str_return} , an adjacent lane flag F _next , a steering determination flag F _str and a lane change intention flag F _{relane_change} are obtained. Based on the state of the flag, the processing after step S5 described later is performed.
That is, first, in step S5, it is determined whether or not to warn that the own vehicle tends to deviate from the traveling lane. Specifically, it is assumed that an alarm is issued when the departure determination flag _FLD is set to “1”, and no alarm is issued otherwise. Note that the alarm timing and the deviation prevention control intervention timing may be shifted.

Subsequently, in step S6, it is determined whether or not deceleration control is performed as part of the lane departure prevention control. Specifically, first, lateral displacement limit value the absolute value of the estimated lateral displacement from the X _C set in the step S3 | XS | calculating a lateral displacement allowance Xy by subtracting. On the other hand, according to the control map of FIG. 9, the deceleration control threshold value Xa corresponding to the curvature β of the traveling lane read in step S1 is set. The deceleration control threshold value Xa is set smaller as the traveling lane curvature β is larger. When the lateral displacement margin value Xy is equal to or less than the deceleration control threshold value Xa, the deceleration control flag F _LG is set to “1” as the one for performing the deceleration control. Otherwise, the deceleration control flag F _{LG is set} to “0”. Reset to “”. That is, even if the lateral displacement margin value Xy is equal, the tighter the curve of the traveling lane, the earlier the timing of deviating from the lane, so when the lateral displacement margin value Xy is equal to or less than the deceleration control threshold value Xa. The deceleration control is performed as a part of the lane departure prevention control.

Subsequently, in step S7, sets calculates a target yaw moment M _S for lane departure prevention. Configuring the target yaw moment _{M S} is performed when departure determination flag _{F LD} is set _(F LD = 1) only. Thereby, when the departure determination flag _FLD is set, the proportional coefficients K ₁ , K ₂ , K _lane , the estimated future lateral displacement XS calculated in the step S4, and the lateral displacement limit value X _C are used. Te, calculates a target yaw moment _{M S} in accordance with the following equation (3).
M _S = K ₁ × K ₂ × K _lane × (XS−X _C ) (3)

Here, the proportional coefficient K ₁ is a proportionality factor determined from the vehicle specification. Moreover, the proportional factor K ₂ is a proportionality coefficient set according to the vehicle running speed V as shown in FIG. 10. The proportional coefficient K _lane is a proportional coefficient that is set to a small value when the lane change intention flag F _{relane_change} is “1”.
Here, in the control map shown in FIG. 10, since a small proportional coefficient K ₂ as the vehicle running speed V is large is set, the target yaw moment M _S becomes small, that is the control amount becomes small. Further, when the lane change intention flag F _{relane_change} is “1”, a small proportional coefficient K _lane is set, so that the target yaw moment M _S becomes small, that is, the control amount becomes small.

The target yaw moment M _S when the departure determination flag F _LD is in the reset state to "0".
Then at step S8, the calculated target brake fluid pressure P _Si of each wheel to return from the output it toward the brake fluid pressure control circuit 7 to the main program. Specifically, with respect to the master cylinder pressure P _m read in step S1, when the wheel master cylinder pressure after based on front-rear braking force distribution and P _mR, deviation determination flag F _LD is and deceleration in the reset state when the control flag _{F LG} is in the reset state, the left and right front wheels 5FL, 5FR wheel cylinders 6FL, target brake fluid pressure _P SFL to _{6FR, P SFR} both the master cylinder pressure _{P m,} and the rear left and right wheels 5RL, the 5RR The target brake fluid pressures P _SRL and P _SRR applied to the wheel cylinders 6RL and 6RR are both the rear wheel master cylinder pressure P _mR .

On the other hand, even when the deceleration control flag F _LG is reset and departure determination flag F _LD is set, performs case analysis in accordance with the magnitude of the target yaw moment M _S calculated at step S7. That is, when the absolute value | M _S | of the target yaw moment is less than the predetermined value M _SO , a difference is generated only in the braking force of the rear left and right wheels, and the absolute value | M _S | of the target yaw moment is the predetermined value M _SO. When this is the case, a difference is generated in the braking force between the front, rear, left and right wheels. Therefore, when the absolute value | M _S | of the target yaw moment is less than the predetermined value M _SO , the front left and right wheel target braking fluid pressure difference ΔP _SF is “0”, and the rear left and right wheel target braking fluid pressure difference ΔP _SR is It is given by equation (4).

Similarly, the front left and right wheel target braking fluid pressure difference ΔP _SF when the absolute value | M _S | of the target yaw moment is equal to or greater than the predetermined value M _SO is the following equation (5), and the rear left and right wheel target braking fluid pressure difference ΔP _SR is It is given by the following equation (6). In the equation, T is a tread (the same _applies to front and rear wheels), K _bF and K _bR are conversion coefficients for converting braking force into braking fluid pressure, and are determined by brake specifications.
ΔP _SR = 2 × K _bR × | M _S | / T (4)
ΔP _SF = 2 × K _bF × (| M _S | −M _SO ) / T (5)
ΔP _SR = 2 × K _bR × | M _SO | / T (6)

Accordingly, the departure flag F _LD is in the set state and the deceleration control flag F _LG is in the reset state, and when the target yaw moment M _S is negative value, i.e., when the vehicle is about to lane departure to the left The target braking fluid pressure P _Si for each of the wheel cylinders 6FL to 6RR is given by the following equation (7).
P _SFL = P _m
P _SFR = P _m + ΔP _SF
P _SRL = P _mR
P _SRR = P _mR + ΔP _SR
... (7)

In contrast, deviation determination flag F _LD is in the set state and the deceleration control flag F _LG is in the reset state, and when the target yaw moment M _S is positive, i.e. the vehicle is about to lane departure to the right The target braking fluid pressure P _Si to the wheel cylinders 6FL to 6RR is given by the following equation (8).
P _SFL = P _m + ΔP _SF
P _SFR = P _m
P _SRL = P _mR + ΔP _SR
P _SRR = P _mR
... (8)

Further, in the present embodiment, when the deceleration control flag F _LG is set, the same braking force is applied to the left and right wheels to decelerate the host vehicle. The target deceleration braking fluid pressure P _G for applying the same braking force to the left and right wheels is a proportional coefficient K _G1 determined from the vehicle specifications and a proportional coefficient set according to the host vehicle traveling speed V shown in FIG. K _G2 and the absolute value of the calculated estimated future lateral displacement in the step S3 | XS | and using the lateral displacement limit value X _C, and a deceleration control threshold value Xa, is calculated according to the following equation (9). Incidentally, in the control map shown in FIG. 11, since a large proportional coefficient K _G2 as the vehicle running speed V is large is set, the target deceleration brake fluid pressure P _G increases, i.e. the deceleration is increased.
P _G = K _G1 × K _G2 × (| XS | −X _C −Xa) (9)

For this target deceleration brake fluid pressure P _G, the wheel target deceleration brake fluid pressure after based on front-rear braking force distribution and P _GR. The target deceleration brake fluid pressure P _G when the deceleration control flag F _LG is reset to "0".
Therefore, the deviation determination flag F _LD is set state and the deceleration control flag F _LG is in the set state, and when the target yaw moment M _S is negative value, i.e., when the vehicle is about to lane departure to the left The target braking fluid pressure P _Si for each of the wheel cylinders 6FL to 6RR is given by the following equation (10).
P _SFL = P _m + P _G / 2
P _SFR = P _m + ΔP _SF + P _G / 2
P _SRL = P _mR + P _GR / 2
P _SRR = P _mR + ΔP _SR + P _GR / 2
... (10)

In contrast, deviation determination flag F _LD is in the set state and the deceleration control flag F _LG is in the reset state, and when the target yaw moment M _S is positive, i.e. the vehicle is about to lane departure to the right The target braking fluid pressure P _Si to the wheel cylinders 6FL to 6RR is given by the following equation (11).
P _SFL = P _m + ΔP _SF + P _G / 2
P _SFR = P _m + P _G / 2
P _SRL = P _mR + ΔP _SR + P _GR / 2
P _SRR = P _mR + P _GR / 2
(11)

According to this processing, if not intentional lane change of the driver, and future estimated lateral displacement XS becomes lateral displacement limit value X _C or higher, the vehicle tends to deviate from the driving lane is set departure determination flag F _LD is determined that calculates a target yaw moment M _S on the basis of the difference between future estimated lateral displacement XS and lateral displacement limit value X _C, the target yaw moment M _S is achieved Thus, the braking force of each wheel is controlled. As a result, for example, when the steering input is small, a yaw moment that prevents the lane departure is generated in the vehicle, the lane departure is prevented, and the traveling speed of the vehicle is reduced by the braking force. Can be prevented.
Here, an operation example of the lane departure prevention control realized by the above-described arithmetic processing will be described with reference to FIG.

First, in step S71 and step S72, the history of the direction indicating switch signal within the latest predetermined period Δt is updated until a departure tendency is detected, that is, until the departure determination flag _FLD becomes “1” (the above-mentioned description). Step S1 to Step S3).
When the departure tendency is detected, that is, when the departure determination flag _FLD becomes “1”, the process proceeds to step S73 to determine whether or not there is a steering intervention by the driver at the present time. Here, it is first determined whether or not there is steering intervention by comparing the steering angle δ with the first set value Δδ ₁ (> Δδ ₂ ) (step S21).

Here, if there is a steering intervention with a steering amount (steering angle) δ greater than or equal to the first set value Δδ ₁ , the process proceeds to step S74, the departure determination flag _{FLD is set} to “0” (step S23), and further step Proceeding to S75, the lane departure prevention control is turned off (not implemented). Further, in the case of steering intervention with the steering amount (steering angle) δ less than the first set value Δδ ₁ , the process proceeds to step S76 while maintaining the departure determination flag _FLD at “1”, and detects the direction indicating switch signal most recently. It is determined whether or not (step S31).

If no direction indicating switch signal has been detected most recently, the process proceeds to step S77, and the switch operation flag F _{sw_turn} is _set to “0” (step S33). Then, the process proceeds to step S87, and intervention of lane departure prevention control based on the normal magnitude of the yaw moment is started. If the direction indicating switch signal is detected most recently, the process proceeds to step S78, and the switch operation flag F _{sw_turn} is _set to “1” (step S32). Then, the process proceeds to step S79, and it is determined whether or not there is a return steering operation most recently (step S41). That is, it is determined whether or not the most recent direction indicating switch canceling operation is a return steering operation.

Here, if there is a return steering operation most recently, the process proceeds to step S80, where the return steering determination flag F _{str_return} is _set to “1”, and the lane change intention flag F _{relane_change} is _set to “1” (step S42). . In step S89, the yaw moment is reduced and intervention for lane departure prevention control is started. If there is no return steering operation, the process proceeds to step S81, and the return steering determination flag F _{str_return} is _set to “0” (step S43). And it progresses to step S82 and it is determined whether there exists an adjacent lane (said step S51).

If there is no adjacent lane, the process proceeds to step S83, and the adjacent lane flag F _{next is set} to “0” (step S53). Then, the process proceeds to step S87, and intervention of lane departure prevention control based on the normal magnitude of the yaw moment is started. If there is no adjacent lane, the process proceeds to step S84, and the adjacent lane flag F _{next is set} to "1" (step S52). Then, the process proceeds to step S85, where it is determined whether there is steering intervention, specifically based on the steering intervention amount. That is, it is determined whether or not there is steering intervention by comparing the steering angle δ with the second set value Δδ ₂ (step S22).

Here, if there is a steering intervention with a steering amount (steering angle) δ greater than or equal to the second set value Δδ ₂ , the process proceeds to step S86, the steering determination flag F _{str is set} to “1” (step S24), and further step Proceeding to S87, lane departure prevention control intervention based on the magnitude of the normal yaw moment is started. Further, in the case of the steering intervention with the steering amount (steering angle) δ less than the second set value Δδ ₂ , the process proceeds to step S88, the steering determination flag F _{str is set} to “0” (step S25), and the lane change intention flag is set. _Set F _{relane_change} to “1”. In step S89, the yaw moment is reduced and intervention for lane departure prevention control is started.

Even if there is a tendency to deviate, the lane departure prevention control is not performed when the driver intervenes with a relatively large rudder angle amount (steering angle amount of Δδ ₁ or more).
Further, when there is a tendency to deviate by the above-described processing, the lane departure prevention control is performed by reducing the yaw moment when the direction indicating switch 20 is operated most recently and the return steering operation is performed. .

As described above, the absolute value of future estimated lateral displacement | XS | based on and the lateral displacement limit value X _C or higher, and to "1" and the departure flag F _LD if there is departure tendency (the Even in such a case, when the direction indicating switch 20 is operated, the departure determination flag _{FLD is set} to “0” based on the operating direction of the direction indicating switch 20. In such a processing procedure, if the direction indicating switch 20 is turned off by the driver's return steering operation after the direction indicating switch 20 is turned on, the absolute value | XS | as long as the deviation tendency based on the value X _C or higher and is detected, deviation determination flag F _LD becomes "1". In this case, when the driver tries to change the lane in the canceled operation direction of the direction indicating switch 20, the lane departure prevention control intervenes.

However, even though the driver has performed a return steering operation, since the driver has operated the direction indicating switch 20 once, it can be said that the driver has an intention to change the lane. Since it can be said that it is shortly after that, since the turn-on operation of the direction indicating switch 20 is canceled by the driver's own return steering operation, the departure determination flag _FLD is maintained at “1”, and the vehicle departs from the lane. If prevention control intervenes, it will give a driver a sense of incongruity when trying to change lanes.

  For this reason, even when there is a tendency to deviate, the direction indicating switch is operated by the return steering operation regardless of the driver's lane intention change when the direction indicating switch is operated most recently and the return steering operation is performed. Lane departure prevention control is performed by reducing the yaw moment. Thereby, it is possible to suppress the intervention of the lane departure prevention control from giving an uncomfortable feeling to the driver who changes the lane.

FIG. 13 shows a traveling example of the host vehicle to which such processing is applied.
At the position of the host vehicle 100A, the direction indicating switch 20 is turned on, and the direction indicating lamp is blinking. And in the position of the own vehicle 100B, it is in the state which the driver | operator tried to change into a lane to an adjacent lane, and was approaching the driving | running | working lane side. Here, when the host vehicle 100C moves to the center side of the traveling lane by the driver's return steering operation, the on operation of the direction indicating switch 20 is canceled. At this time, the direction indicator lamp is also extinguished.

  When the driver tries to move again to the adjacent lane from such a travel position and moves to the position of the host vehicle 100D, the direction indicator switch 20 is turned off, and the lane departure prevention control intervenes. End up. On the other hand, by applying the present invention, even when there is a tendency to deviate, the direction indicating switch has been operated most recently and the return steering operation has been performed. To come. Thereby, it is possible to suppress the intervention of the lane departure prevention control from giving an uncomfortable feeling to the driver who changes the lane.

  As can be seen from this point, the above processing is performed when the operation direction of the latest direction indicating switch 20 matches the departure direction. That is, when the operation direction of the latest direction indicating switch 20 and the departure direction are opposite, the direction in which the driver wants to change the lane is the opposite direction to the departure direction. Regardless of the normal lane departure prevention control.

Further, when there is a tendency to deviate by the above-described processing, the direction indicating switch 20 is operated most recently, but when the return steering operation is not performed, that is, the driver himself cancels the direction indicating switch 20. In such a case, the following departure prevention control is performed based on the steering operation amount and the presence or absence of an adjacent lane.
That is, when there is a tendency to deviate, the direction indicating switch 20 is operated most recently, but the return steering operation is not performed, there is an adjacent lane, and the driver has a small steering angle amount (a steering angle less than Δδ _2). Lane departure prevention control is performed by reducing the yaw moment.

For example, in this case, the driver himself / herself cancels the direction indicating switch 20 because the own vehicle has approached the adjacent lane in the traveling lane. In such a case, the driver's intention is respected, and the yaw moment is reduced to perform lane departure prevention control.
Further, when there is deviation tendency, although recently direction indicating switch 20 is operated, without being returning steering operation, and there is an adjacent lane, and a steering angle of moderate driver (.DELTA..delta less than _1, When steering intervention is performed with a steering angle amount of Δδ ₂ or more), lane departure prevention control is performed with a yaw moment having a normal magnitude. In other words, even when the driver himself cancels the direction indicating switch 20 due to the vehicle approaching the adjacent lane in the traveling lane, if the steering amount is large, the lane departure prevention is greater than the driver's intention. Prioritizing the necessity of control, lane departure prevention control is intervened by a yaw moment of a normal magnitude.

Further, when there is a tendency to deviate, the direction indicating switch 20 is operated most recently, but when the return steering operation is not performed and there is no adjacent lane, the lane departure prevention control is performed by the normal magnitude yaw moment. It becomes like this. For example, assuming that there is a road shoulder in the departure direction because there is no adjacent lane, lane departure prevention control is performed with a normal magnitude of yaw moment.
On the other hand, when there is a tendency to deviate by the above-described processing, if the direction indicating switch 20 is not operated most recently, the lane departure prevention control is performed by the normal magnitude yaw moment regardless of the presence or absence of steering intervention by the driver. I do. In this case, since the direction indicating switch 20 has not been operated most recently, it is assumed that the current departure tendency is not due to the driver's intention to change the lane or the like, and lane departure prevention control is performed with a normal magnitude of yaw moment. .

The embodiments of the present invention have been described above. However, the present invention is not limited to being realized as the above-described embodiment.
That is, in the above-described embodiment, the yaw moment (target yaw moment M _S ) used in the lane departure prevention control is reduced when the lane change intention flag F _{relane_change} is “1”. However, it is not limited to this. That is, if the purpose is to suppress the lane departure prevention control, other lane departure prevention control contents may be changed. For example, although the traveling speed of the vehicle is decelerated by the braking force, the deceleration may be reduced.

Further, in order to reduce the yaw moment, in addition to reducing the proportional coefficient K _lane and reducing the overall yaw moment as described above, the yaw moment at the beginning of the lane departure prevention control intervention is also included. It is also included that the yaw moment is gradually increased after the lane departure prevention control is reduced. In this case, for example, the amount of yaw moment applied as a whole through the lane departure prevention control may be the same as the amount of yaw moment applied through the normal lane departure prevention control.

In the above-described embodiment, the return steering operation is detected based on the history of the steering torque. However, it is not limited to this. For example, the return steering operation may be detected based on the history of the steering angle.
In this embodiment, the presence / absence of the return steering operation is detected. However, the present invention is not limited to this, and the yaw moment may be reduced simply based on the presence / absence of the operation history of the direction indicating switch in the past. good. Further, the vehicle state control unit 8 may change the yaw moment to zero, for example, in addition to changing the yaw moment small. At this time, only a lane departure warning is notified in step S5, and no yaw moment is applied.

  In the description of the above-described embodiment, the process of step S3 in FIG. 2 by the vehicle state control unit 8 realizes a departure determination unit that determines that the host vehicle tends to depart from the traveling lane. The processing in step S4 in FIG. 2 by the control unit 8 realizes a direction indicator operation detecting means for detecting the operation of the direction indicator, and the processing in steps S5 to S8 in FIG. When the deviation determining means determines that there is a tendency to deviate, and when the direction indicator operation detecting means detects an ON operation of the direction indicator, the indication direction of the direction indicator and the deviation tendency Based on the direction, a deviation prevention control intervention means for intervening the deviation prevention control is realized, and the processing of FIG. The deviation prevention control content changing means for changing the deviation prevention control content to be intervened by the departure prevention control intervention means based on the operation history of the direction indicator stored in the storage means when the direction indicator is in the OFF state. Realized.

It is an embodiment of the present invention and is a schematic configuration diagram showing an example of a vehicle equipped with a lane departure prevention device. It is a flowchart which shows the arithmetic processing for lane departure prevention control performed in the vehicle state control unit with which the said vehicle is mounted. It is a flowchart which shows the process of the driver | operator determination of the arithmetic processing for the said lane departure prevention control. It is a flowchart which shows the process of the steering intervention determination in the process of the said driver | operator intention determination. It is a flowchart which shows the process of the direction instruction | indication switch determination in the process of the said driver | operator intention determination. It is a characteristic view which shows the relationship between a direction instruction | indication switch signal and a steering angle. It is a flowchart which shows the process of the return steering operation determination in the process of the said driver | operator intention determination. It is a flowchart which shows the process of adjacent lane determination in the process of the said driver | operator intention determination. It is a control map used for the arithmetic processing for the said lane departure prevention control. It is a control map used for the arithmetic processing for the said lane departure prevention control. It is a control map used for the arithmetic processing for the said lane departure prevention control. It is the flowchart used for description of an example of the lane departure prevention control implement | achieved by the arithmetic processing for the said lane departure prevention control. It is a figure which shows the example of driving | running | working of the own vehicle.

Explanation of symbols

5FL to 5RR Wheel 6FL to 6RR Wheel cylinder 7 Braking fluid pressure control circuit 8 Vehicle state control unit 10 Navigation system 13 CCD camera 14 Camera controller 15 Acceleration sensor 19 Steering angle sensor 20 Direction indication switch 22FL to 22RR Wheel speed sensor

Claims (7)

Deviation judging means for judging that the own vehicle is in a tendency to deviate from the driving lane,
Direction indicator operation detecting means for detecting operation of the direction indicator;
Storage means for storing an operation history of the direction indicator;
When it is determined that the departure determination unit has a departure tendency, and the direction indicator operation detection unit detects an ON operation of the direction indicator, the direction indicated by the direction indicator and the direction of the departure tendency Based on the above, a deviation prevention control intervention means for intervening deviation prevention control,
When the direction indicator is in an off state, based on the operation history of the direction indicator stored in the storage unit, the departure prevention control content changing unit for changing the departure prevention control content to be intervened by the departure prevention control intervention unit;
A lane departure prevention apparatus comprising:   The lane departure prevention apparatus according to claim 1, wherein the departure prevention control content changing means changes the departure prevention control content based on a driver's steering operation. A determination means for determining whether the turn-off state of the direction indicator is due to cancellation of the operation of the direction indicator by a return steering operation by the driver;
The lane departure prevention apparatus according to claim 1 or 2, wherein the departure prevention control content changing unit changes the departure prevention control content based on a determination result of the determination unit.   When the determination result by the determination means is a result that the turn-off state of the direction indicator is due to cancellation of the operation of the direction indicator by a return steering operation by the driver, the deviation prevention control content change 4. The lane departure prevention apparatus according to claim 3, wherein the means suppresses the departure prevention control.   2. The departure prevention control content changing unit changes the departure prevention control content based on a direction instruction operation history from a time point when the departure determination unit determines a departure tendency to a predetermined time ago. The lane departure prevention apparatus according to any one of claims 1 to 4. The departure prevention control intervention means has a yaw control means for giving a yaw moment in a direction to prevent departure from the host vehicle,
6. The lane departure according to claim 1, wherein the departure prevention control content changing unit changes a yaw moment by the yaw control unit to a value smaller than a normal departure prevention control. Prevention device. The departure prevention control intervention means has a yaw control means for giving a yaw moment in a direction to prevent departure from the host vehicle,
6. The departure prevention control content changing unit changes a yaw moment by the yaw control unit to zero and notifies a driver of a departure warning. Lane departure prevention device.

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