JP4835309B2 - Lane departure prevention device - Google Patents

Description

  The present invention relates to a lane departure prevention device that prevents a vehicle from departing when the vehicle is about to depart from a traveling lane.

In Patent Document 1, when the vehicle tends to deviate from the travel lane, a steering torque is generated so that a yaw moment that avoids the departure from the travel lane is generated, and a yaw angle c with respect to the direction of the travel lane is set. A technique is disclosed in which the generation of the steering torque is stopped when it is smaller than the predetermined threshold value Cth, that is, when the traveling direction of the vehicle with respect to the traveling lane is parallel or substantially parallel.
JP 2004-70853 A

However, even if an attempt is made to set the threshold value Cth so that the vehicle posture after the control for avoiding the lane departure is made parallel or substantially parallel to the traveling lane, the vehicle state (vehicle traveling state, etc.) Depending on the driving environment (road radius condition, etc.), there may be variations in the vehicle posture after the end of control. Due to variations in the vehicle posture after the end of the control, the traveling direction with respect to the traveling lane will be different for each control, giving the driver a sense of incongruity.
The subject of this invention is suppressing the dispersion | variation in the vehicle attitude | position after completion | finish of the control which avoids a lane departure.

In order to solve the above problems, the lane departure prevention apparatus according to the present invention prevents the vehicle from deviating from the traveling lane when it is determined that the tendency of the vehicle to deviate from the traveling lane is high. Control means for starting the prevention control and ending the control at a predetermined timing, and detecting the yaw angle formed between the traveling lane and the vehicle as the vehicle state at the start of the lane departure prevention control by the state detection means The lane departure prevention when the vehicle returns to the traveling lane, for example, as the yaw angle formed between the traveling lane and the vehicle as the vehicle state detected at the start of the lane departure preventing control by the state detecting means becomes smaller. the end timing of the control is adapted to quickly by the control end timing correction means, and said control means, for example, after the lane departure prevention control is started When the yaw angle formed between the travel lane and the vehicle returns to a predetermined yaw angle, the lane departure prevention control is finished, and the control end timing correction means is, for example, at the start of the lane departure prevention control The end timing of the lane departure prevention control is advanced by increasing the predetermined yaw angle as the yaw angle formed by the traveling lane and the vehicle decreases .

According to the present invention, the end timing of the lane departure prevention control when the vehicle returns to the traveling lane is corrected based on the yaw angle formed between the traveling lane and the vehicle as the vehicle state at the start of the lane departure prevention control. it is, the vehicle state at the start of lane departure prevention control is suppressing the influence on the orientation of the vehicle during the lane departure prevention control ends, to suppress the variation occurs in the vehicle posture during the lane departure prevention control ends Can do.

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.
(First embodiment)
First, the first embodiment will be described.
(Constitution)
1st Embodiment of this invention is a rear-wheel drive vehicle carrying the lane departure prevention apparatus based on this invention. This rear-wheel drive vehicle is equipped with an automatic transmission and a conventional differential gear, and a braking device capable of independently controlling the braking force of the left and right wheels for both the front and rear wheels.

FIG. 1 is a schematic configuration diagram showing the first embodiment.
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 according to the amount of depression of the brake pedal 1 by the driver is shown. It supplies to each wheel cylinder 6FL-6RR of each wheel 5FL-5RR. Further, a braking fluid pressure control unit 7 is interposed between the master cylinder 3 and each wheel cylinder 6FL-6RR, and the braking fluid pressure control unit 7 individually controls the braking fluid pressure of each wheel cylinder 6FL-6RR. It is also possible to control.

  The brake fluid pressure control unit 7 uses a brake fluid pressure control unit used in, for example, anti-skid control (ABS), traction control (TCS), or vehicle dynamics control device (VDC). The brake fluid pressure control unit 7 can control the brake fluid pressure of each of the wheel cylinders 6FL to 6RR independently, but when a brake fluid pressure command value is input from the braking / driving force control unit 8 described later, The brake fluid pressure is controlled according to the brake fluid pressure command value.

For example, the brake fluid pressure control unit 7 includes an actuator in the hydraulic pressure supply system. Examples of the actuator include a proportional solenoid valve capable of controlling each wheel cylinder hydraulic pressure to an arbitrary braking hydraulic pressure.
The vehicle is provided with a drive torque control unit 12. The drive torque control unit 12 controls the drive torque to the rear wheels 5RL and 5RR which are drive wheels by controlling the operating state of the engine 9, the selected gear ratio of the automatic transmission 10, and the throttle opening of the throttle valve 11. To do. The drive torque control unit 12 controls the operating state of the engine 9 by controlling the fuel injection amount and ignition timing, and simultaneously controlling the throttle opening. The drive torque control unit 12 outputs the value of the drive torque Tw used for control to the braking / driving force control unit 8.

The drive torque control unit 12 can control the drive torque of the rear wheels 5RL and 5RR independently. However, when a drive torque command value is input from the braking / driving force control unit 8, the drive torque is controlled. Drive wheel torque is also controlled according to the command value.
In addition, this vehicle is provided with an imaging unit 13 with an image processing function. The imaging unit 13 is provided for detecting the position of the vehicle in the traveling lane for detecting the lane departure tendency of the vehicle. The imaging unit 13 is configured to capture an image with a monocular camera including a CCD (Charge Coupled Device) camera installed so as to capture the front of the vehicle. The imaging unit (front camera) 13 is installed in the front part of the vehicle.

The imaging unit 13 detects a lane marking such as a white line (lane marker) from a captured image in front of the vehicle, and detects a traveling lane based on the detected white line. Further, the imaging unit 13 calculates an angle (yaw angle) φ _front formed between the traveling lane and the longitudinal axis of the vehicle, a lateral displacement X _{front with} respect to the traveling lane, a traveling lane curvature β, and the like based on the detected traveling lane. To do.
Thus, the imaging unit 13 detects the white lines that form a travel lane, based on the white lines that the detected, calculates the yaw angle phi _front. The imaging unit 13 outputs the calculated yaw angle φ _front , lateral displacement X _front, travel lane curvature β, and the like to the braking / driving force control unit 8.

In the present invention, the lane marker may be detected by detection means other than image processing. For example, the lane marker may be detected by a plurality of infrared sensors attached to the front of the vehicle, and the traveling lane may be detected based on the detection result.
Further, the present invention is not limited to the configuration in which the traveling lane is determined based on the white line. In other words, when there is no white line (lane marker) on the road to recognize the driving lane, information on road shape and surrounding environment obtained by image processing and various sensors, the road range suitable for the vehicle and the driver May estimate the runway range where the vehicle should travel and determine the travel lane. For example, when there is no white line on the runway and both sides of the road are separated, the asphalt portion of the runway is determined as the travel lane. Moreover, what is necessary is just to determine a driving lane in consideration of the information, when there is a guardrail, a curb, etc.

Further, the traveling lane curvature β may be calculated based on a steering angle δ of the steering wheel 21 described later.
The vehicle is provided with a navigation device 14. The navigation device 14 detects the longitudinal acceleration Yg or lateral acceleration Xg generated in the vehicle or the yaw rate φ ′ generated in the vehicle. The navigation device 14 outputs the detected longitudinal acceleration Yg, lateral acceleration Xg, and yaw rate φ ′ to the braking / driving force control unit 8 together with the road information.
Each value may be detected by a dedicated sensor. That is, the longitudinal acceleration Yg and the lateral acceleration Xg may be detected by the acceleration sensor, and the yaw rate φ ′ may be detected by the yaw rate sensor.

  Further, the vehicle includes a master cylinder pressure sensor 17 that detects an output pressure of the master cylinder 3, that is, a master cylinder hydraulic pressure Pm, an accelerator pedal depression amount that detects an accelerator pedal depression amount, that is, an accelerator opening .theta. A steering angle sensor 19 for detecting a steering angle (steering angle) δ of the wheel 21, a direction indicating switch 20 for detecting a direction indicating operation by a direction indicator, and a rotation speed of each of the wheels 5FL to 5RR, so-called wheel speed Vwi (i = Wheel speed sensors 22FL to 22RR that detect = fl, fr, rl, rr) are provided. Detection signals detected by these sensors and the like are output to the braking / driving force control unit 8.

  Next, calculation processing (processing routine) performed by the braking / driving force control unit 8 will be described. FIG. 2 is a flowchart showing the procedure of the arithmetic processing. This calculation process is executed by a timer interrupt every predetermined sampling time ΔT every 10 msec., For example. Although no communication process is provided in the process shown in FIG. 2, information obtained by the calculation process is updated and stored in the storage device as needed, and necessary information is read out from the storage device as needed.

As shown in FIG. 2, when the process is started, first, in step S1, various data are read from each sensor, controller, and control unit. Specifically, the longitudinal acceleration Yg, the lateral acceleration Xg, the yaw rate φ ′ and road information obtained by the navigation device 14, the wheel speeds Vwi, the steering angle δ, the accelerator opening θ, the master cylinder hydraulic pressure detected by the sensors. The Pm and direction switch signals, the driving torque Tw from the driving torque control unit 12, and the lateral displacement X _front and the traveling lane curvature β are read from the imaging unit 13.

Subsequently, in step S2, the vehicle speed V is calculated. Specifically, the vehicle speed V is calculated by the following equation (1) based on the wheel speed Vwi read in step S1.
For front wheel drive V = (Vwr1 + Vwrr) / 2
For rear wheel drive V = (Vwfl + Vwfr) / 2
... (1)
Here, Vwfl and Vwfr are the wheel speeds of the left and right front wheels, and Vwrl and Vwrr are the wheel speeds of the left and right rear wheels. That is, in the equation (1), the vehicle speed V is calculated as the average value of the wheel speeds of the driven wheels. In this embodiment, since the vehicle is a rear-wheel drive vehicle, the vehicle speed V is calculated from the latter equation, that is, the wheel speed of the front wheels.

The vehicle speed V calculated in this way is preferably used during normal travel. For example, when an ABS (Anti-lock Brake System) control or the like is operating, an estimated vehicle speed estimated in the ABS control is used as the vehicle speed V.
Subsequently, in step S3, the yaw angle φ _front is calculated. Specifically, the yaw angle φ _{front of the} vehicle with respect to the far white line detected by the imaging unit 13 is calculated.

Incidentally, thus calculated yaw angle phi _front is made to the measured value by the imaging unit 13, calculation instead of using the actual measurement values, based on the white line of the vehicle near the imaging unit 13 is captured, the yaw angle phi _front You can also That is, for example, the yaw angle _φfront is calculated by the following equation (2) using the lateral displacement _Xfront read in step S1.
φ _front = tan ⁻¹ (V / dX ′ (= dY / dX)) (2)
Here, dX is a change amount per unit time of the lateral displacement X, dY is a change amount in the traveling direction per unit time, and dX ′ is a differential value of the change amount dX.

Further, when the yaw angle φ _front is calculated based on the white line near the vehicle, it is not limited to calculating the yaw angle φ _front using the lateral displacement X as in the equation (2). For example, a white line detected in the vicinity of the vehicle can be extended far away, and the yaw angle φ _front can be calculated based on the extended white line. V is the vehicle speed calculated in step S2.

Subsequently, in step S4, an estimated lateral displacement is calculated. Specifically, using the travel lane curvature β obtained in step S1 and the lateral displacement X _front of the current vehicle, the vehicle speed V obtained in step S2, and the yaw angle φ _front obtained in step S3, The estimated lateral displacement Xs is calculated by the equation (3).
Xs = Tt · V · (φ _front + Tt · V · β) + X _front (3)
Here, Tt is the vehicle head time for calculating the forward gaze distance. When this vehicle head time Tt is multiplied by the own vehicle speed V, a forward gazing 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. According to this equation (3), the larger the yaw angle _{phi front,} estimated lateral displacement Xs increases.

  Subsequently, in step S5, a yaw moment to be applied to the vehicle as lane departure prevention control (hereinafter referred to as a reference yaw moment) is calculated. In the lane departure prevention control, when the vehicle tends to deviate from the traveling lane, a predetermined yaw moment (predetermined lane departure prevention control amount) is given to the vehicle to prevent the vehicle from deviating from the traveling lane. In step S5, the yaw moment (reference yaw moment Ms0) is calculated based on the actual running state. FIG. 3 shows the definition of values used in this process.

Specifically, for calculating a reference yaw moment Ms0 by the following equation (4) based on the estimated lateral displacement Xs obtained and lateral displacement limit distance X _L in the step S4.
Ms0 = K1 · K2 · (| Xs | −X _L ) (4)
Here, K1 is a proportional gain determined from vehicle specifications, and K2 is a gain that varies according to the vehicle speed V. FIG. 4 shows an example of the gain K2. As shown in FIG. 4, the gain K2 becomes a small value in the low speed range, and when the vehicle speed V becomes a certain value, the gain K2 also increases as the vehicle speed V increases. It becomes a constant value.

Further, the lateral displacement limit distance _XL is a value that can be generally grasped as the vehicle tends to depart from the lane, and is obtained as an experience value, an experimental value, or the like. For example, the lateral displacement limit distance _XL is a value indicating the position of the boundary line of the traveling lane, and is calculated by the following equation (5).
X _L = (L−H) / 2 (5)
Here, L is the lane width of the travel lane (width between white lines forming the travel lane), and H is the width of the vehicle. The lane width L is obtained by processing the captured image by the imaging unit 13.

From the above, according to the equation (4), the estimated lateral displacement Xs and the difference between the lateral displacement limit distance X _L increases, the reference yaw moment Ms0 increases, also the relationship of estimated lateral displacement Xs and yaw angle phi _front from (the (3) reference expression), the larger the yaw angle _{phi front,} the reference yaw moment Ms0 increases.
Further, the reference yaw moment Ms0 is calculated by the above equation (4) when the departure determination flag Fout set in step S6 described later is ON, and the reference yaw moment Ms0 is set to 0 when the departure determination flag Fout is OFF. Set.

Subsequently, in step S6, a deviation tendency of the vehicle with respect to the traveling lane is determined. Specifically, the lateral displacement limit distance X _L used for calculation of the reference yaw moment Ms0 in step S5 and a departure-tendency threshold value, and this departure-tendency threshold value X _L, in step S4 The estimated lateral displacement Xs is compared to determine the departure tendency.
Setting (≧ _X L | | Xs), it is determined that there is a lane departure tendency, the ON and the departure flag Fout Here, when the estimated lateral displacement (absolute value) Xs is greater than or equal departure-tendency threshold value _{X L} and, when the estimated lateral displacement Xs is smaller than departure-tendency threshold value _{X L (| Xs | <X} L), it is determined that no lane departure tendency, setting the departure flag Fout to OFF.

Note that the lane departure tendency may be determined using the actual lateral displacement _Xfront (estimated lateral position Xs when Tt = 0) instead of the estimated lateral position Xs. In this case, the actual lateral displacement (absolute _{value) X} If _front is above the threshold _{X L} for determining the tendency to deviate _{(| X front} | ≧ _X L), it is determined that there is a lane departure tendency, the departure flag Fout Set to ON.
Further, as a condition for enabling the departure determination flag Fout to be set to ON, after the departure determination flag Fout is set to OFF, the vehicle is not in a departure state ((| Xs | <X _L ) or (| X _front | <X _L )). In addition, as a condition that allows the departure determination flag Fout to be set to ON, a time condition such as a predetermined time has elapsed after the departure determination flag Fout is set to OFF can be added.

Further, in FIG. 3, the deviation tendency determination threshold value (lateral displacement limit distance) _XL is set in the travel lane of the vehicle, but the present invention is not limited to this and is set outside the travel lane. May be. Further, the departure tendency determination threshold value _XL is not limited to that in which the departure tendency is determined before the vehicle departs from the travel lane, but for example, the departure tendency is determined after at least one of the wheels has deviated from the lane. It may be set.

After setting the departure determination flag Fout as described above, the departure direction Dout is determined based on the lateral displacement X. Specifically, when the vehicle is laterally displaced from the center of the lane to the left, the direction is set as the departure direction Dout (Dout = LEFT), and when the vehicle is laterally displaced from the center of the lane to the right, the direction is changed to the departure direction Dout. (Dout = RIGHT).
When anti-skid control (ABS), traction control (TCS), or vehicle dynamics control (VDC) is operating, the departure determination flag Fout is turned off so as not to operate the lane departure prevention control. It may be set to.

  Further, the departure determination flag Fout may be finally set in consideration of the driver's intention to change the lane. For example, when the direction indicated by the direction switch signal (the blinker lighting side) and the direction indicated by the departure direction Dout are the same, it is determined that the driver has intentionally changed the lane, and the departure determination flag Fout is turned off. Change to That is, it is changed to the determination result that there is no lane departure tendency. When the direction indicated by the direction switch signal (the blinker lighting side) is different from the direction indicated by the departure direction Dout, the departure determination flag Fout is maintained and the departure determination flag Fout is kept ON. That is, the determination result that there is a tendency to depart from the lane is maintained.

  When the direction indicating switch 20 is not operated, the departure determination flag Fout is finally set based on the steering angle δ. That is, when the driver is steering in the lane departure direction, when both the steering angle δ and the change amount of the steering angle (change amount per unit time) Δδ are equal to or larger than the set value, the driver is conscious. Therefore, it is determined that the lane has been changed, and the departure determination flag Fout is changed to OFF.

Subsequently, in step S7, the end timing of the output (giving) of the yaw moment to the vehicle in the lane departure prevention control is determined.
Based on the determination of the departure tendency in step S6, the lane departure tendency is resolved by the vehicle returning to the traveling lane or the vehicle changing lanes at the driver's intention (Fout = OFF). As a result, the lane departure prevention control is terminated, that is, the output (giving) of the yaw moment to the vehicle is terminated.

In step S7, in addition to the determination of the departure tendency, the yaw angle φ _front formed by the travel lane and the longitudinal axis of the vehicle is a predetermined value (control end posture) φ _end (for example, 0 ° (travel lane and If the angle is parallel to the longitudinal axis of the vehicle), hereinafter referred to as the control end determination yaw angle), it is determined that the lane departure prevention control end timing. If it is determined that the lane departure prevention control has ended (for example, φ _front <φ _end ), the departure determination flag Fout is set to OFF.
Subsequently, in step S8, a target yaw moment that is finally used as a control command value is set.

The lane departure prevention control of the present embodiment is based on the premise that the lane departure prevention control processing routine (the processing routine of FIG. 2) is executed a plurality of times before completion of lane departure avoidance, that is, yaw moment (specifically, Assumes that the target yaw moment Ms) is continuously applied to the vehicle in order to avoid the lane departure of the vehicle, and thus, a series of processes performed from the start of control to the end of control. According to the routine, the yaw moment (control amount) gradually increases and then gradually decreases.
In step S8, on the premise that such a yaw moment output form is used, a target yaw moment Ms is calculated by performing a limiter process on the reference yaw moment Ms0 calculated in step S5. For this reason, first, a limiter for performing the limiter process is set as a default value.

FIG. 5 shows the change with time of the reference yaw moment Ms0.
As shown in FIG. 5, an increase-side change amount limiter Lup is set as a limiter for limiting an increase rate of the reference yaw moment Ms0 on the increase side (value at the start of control or the first half of control), and the maximum value (control The maximum value limiter Lmax is set as a limiter that limits the value of the middle plate), and the decrease-side change amount limiter Ldown is set as a limiter that limits the decrease rate of the reference yaw moment Ms0 on the decrease side (value at the end of control or the latter half of the control). .

Here, the increase side change amount limiter Lup and the decrease side change amount limiter Ldown correspond to the change amount within one processing routine time of the lane departure prevention control. Further, the increase side change amount limiter Lup, the maximum value limiter Lmax, and the decrease side change amount limiter Ldown smooth the minimum yaw moment necessary for the vehicle to avoid deviation from the driving lane based on experience values and experimental values. To be changed
The increase side change limiter Lup, the maximum value limiter Lmax, and the decrease side change amount limiter Ldown are set as default values, and the set increase side change limiter Lup, maximum value limiter Lmax, and decrease side change limiter Ldown are set. The reference yaw moment Ms0 limited by the above is calculated as the target yaw moment Ms.

FIG. 6 shows the result obtained by limiting the reference yaw moment Ms0 with these limiters Lup, Lmax, and Ldown, that is, the target yaw moment Ms.
When the increase side change limiter Lup is small, the increase side inclination (increase rate) of the target yaw moment Ms is small, and when the decrease side change limiter Ldown is small, the decrease side inclination (decrease) of the target yaw moment Ms is reduced. Ratio) becomes smaller.

  Subsequently, in step S9, the end timing (end timing of the lane departure prevention control) of the output (giving) of the yaw moment to the vehicle by the lane departure prevention control is corrected. Specifically, first, when the vehicle is in a lane departure state (immediately after the lane departure is determined), the response characteristic (response sensitivity) of the vehicle behavior to the lane departure prevention control is estimated. Here, the response characteristic of the vehicle behavior to the lane departure prevention control is a response characteristic of the vehicle behavior to the yaw moment application when the yaw moment is applied to the vehicle as the lane departure prevention control, and the response characteristic ( When the response sensitivity is high, the vehicle attitude (yaw angle φ) is likely to return in the lane avoidance direction, and when the response characteristic (response sensitivity) is low, the vehicle attitude (yaw angle φ) is in the lane avoidance direction. Is difficult to return. Then, the yaw moment output end timing is corrected based on such response characteristics. FIG. 7 shows the processing procedure.

  As shown in FIG. 7, when the process is started, first, in step S21, it is determined whether or not the vehicle is in a lane departure state (lane departure has started). Specifically, it is determined whether or not the departure determination flag Fout set in step S6 has changed from OFF to ON. Here, the process of step S21 is repeated until it is determined that the vehicle is in a lane departure state (lane departure has started). If it is determined that the vehicle is in a lane departure state (lane departure has started), the process proceeds to step S22.

In step S22, a yaw angle (hereinafter referred to as a lane departure yaw angle) φ _depart formed between the traveling lane (white line) and the vehicle is detected. Since this step S22 is a step that proceeds when it is determined in step S21 that the vehicle is in a lane departure state, the yaw angle detected in step S22 is the yaw angle at the time of lane departure determination. This yaw angle (hereinafter referred to as a lane departure yaw angle) _φdepart is detected by the imaging unit 13 ( _φdepart = _φfront ).

Subsequently, in step S23, a response characteristic of the vehicle behavior with respect to the lane departure prevention control (hereinafter referred to as a vehicle behavior response characteristic estimated value) is set based on the lane departure yaw angle _φdepart detected in step S22. Specifically, the vehicle behavior response characteristic estimated value α is decreased as the lane departure yaw angle _φdepart increases. The vehicle behavior response characteristic estimated value α indicates that the larger the value, the higher the vehicle behavior response characteristic with respect to the lane departure prevention control (estimation).

FIG. 8 shows an example of the relationship between the lane departure yaw angle _φdepart and the vehicle behavior response characteristic estimated value α.
As shown in FIG. 8, the vehicle behavior response characteristic estimated value α decreases in a quadratic function as the lane departure yaw angle _φdepart increases. With reference to such a characteristic diagram, a vehicle behavior response characteristic estimated value α is set based on the lane departure yaw angle _φdepart .
Thus, for example, as shown in FIG. 9, in the running state of the vehicle 101 in FIG. 9, the lane departure yaw angle φ _depart is φ _depart 1, and at this time, this lane departure yaw angle φ _depart corresponds to Then, the vehicle behavior response characteristic estimated value α is set to α1, and as shown in the traveling state of the vehicle 101 in (b), the lane departure yaw angle _φdepart is (a) the lane departure yaw angle _φdepart 1. _Is greater than φ _depart 2 (> φ _depart 1), the vehicle behavior response characteristic estimated value α is greater than the vehicle behavior response characteristic estimated value α1 of (a) according to the lane departure yaw angle φ _depart 2. Large α2 (> α1) is set.

  Regarding the setting of the vehicle behavior response characteristic estimated value α, the vehicle behavior response characteristic estimated value α is obtained according to the yaw angle φ that changes within a predetermined time after the start of the lane departure prevention control, and the maximum value is set. The latched maximum value may be set to the final vehicle behavior response characteristic estimated value α. That is, in the present embodiment, at least one of the vehicle state and the driving environment is detected at the start of the lane departure prevention control, but at the start of the lane departure prevention control, a predetermined value after the start of the lane departure prevention control is detected. Including time.

Subsequently, in step S24, based on the vehicle behavior response characteristic estimated value α set in step S23, the control end determination yaw angle φ _end used for determining the end of the lane departure prevention control in step S7 is corrected (set). To do. Specifically, the control end determination yaw angle φ _end is corrected to a shallower angle (the degree of parallelism with the travel lane increases) as the vehicle behavior response characteristic estimated value α increases.

FIG. 10 shows an example of the relationship between the vehicle behavior response characteristic estimated value α and the control end determination yaw angle φ _end .
As shown in FIG. 10, in the region where the vehicle behavior response characteristic estimated value α is small, the control end determination yaw angle φ _end becomes a certain small value (φ _end <0, the angle toward the traveling lane), and the vehicle behavior. When the response characteristic estimated value α reaches a certain value, the control end determination yaw angle φ _end also increases as the vehicle behavior response characteristic estimated value α increases, and then the control ends when the vehicle behavior response characteristic estimated value α reaches a certain value. The determination yaw angle φ _end is a large and constant value (φ _end = 0, an angle parallel to the travel lane). With reference to such a characteristic diagram, the control end determination yaw angle φ _end is corrected (set) based on the vehicle behavior response characteristic estimated value α.

Subsequently, in step S10, when the departure determination flag Fout is ON, sound output or display output is performed as an alarm for avoiding lane departure.
When the departure determination flag Fout is ON, that is, when the absolute value | Ms | of the target yaw moment Ms is larger than 0, the application of the yaw moment (target yaw moment Ms) to the vehicle is started as lane departure prevention control. Therefore, the alarm is output simultaneously with the application of the yaw moment. However, the alarm output timing is not limited to this, and may be earlier than the start timing of the yaw moment application, for example.

Subsequently, in step S11, a target brake hydraulic pressure for each wheel is calculated. Specifically, it is calculated as follows.
When the departure determination flag Fout is OFF, that is, when the target yaw moment Ms is 0 (when lane departure prevention control is not performed), as shown in the following equations (6) and (7), the target braking of each wheel is performed. The hydraulic pressure Psi (i = fl, fr, rl, rr) is set to the braking hydraulic pressure Pmf, Pmr.
Psfl = Psfr = Pmf (6)
Psrl = Psrr = Pmr (7)
Here, Pmf is the brake fluid pressure for the front wheels. Further, Pmr is the braking fluid pressure for the rear wheels, and is a value calculated based on the braking fluid pressure Pmf for the front wheels in consideration of the front-rear distribution. For example, if the driver is operating a brake, the brake fluid pressures Pmf and Pmr are values corresponding to the amount of brake operation (master cylinder fluid pressure Pm).

On the other hand, when the departure determination flag Fout is ON, that is, when the absolute value | Ms | of the target yaw moment Ms is larger than 0 (when a determination result that there is a tendency to depart from the lane is obtained), the setting is made in step S9. Based on the target yaw moment Ms, the front wheel target braking hydraulic pressure difference ΔPsf and the rear wheel target braking hydraulic pressure difference ΔPsr are calculated. Specifically, the target braking hydraulic pressure differences ΔPsf and ΔPsr are calculated by the following equations (8) and (9).
ΔPsf = 2 · Kbf · (Ms · FR _ratio ) / T (8)
ΔPsr = 2 · Kbr · (Ms · (1-FR _ratio )) / T (9)

Here, the front and rear wheel hydraulic pressure distribution ratio FR _ratio is the value set in step S10. T represents a tread. The tread T is set to the same value before and after for convenience. Kbf and Kbr are conversion coefficients for the front wheels and the rear wheels when the braking force is converted into the braking hydraulic pressure, and are determined by the brake specifications. The target braking hydraulic pressure differences ΔPsr and ΔPsr are values for determining the distribution of the braking force applied to each wheel according to the magnitude of the target yaw moment Ms, and are values for generating a braking force difference between the front, rear, left and right wheels. .

Then, the final target brake hydraulic pressure Psi (i = fl, fr, rl, rr) of each wheel is calculated using the calculated target brake hydraulic pressure differences ΔPsf, ΔPsr. Specifically, when the departure determination flag Fout is ON and the departure direction Dout is LEFT, that is, when there is a lane departure tendency with respect to the white line on the left side, the target braking hydraulic pressure Psi of each wheel is expressed by the following equation (10). (I = fl, fr, rl, rr) is calculated.
Psfl = Pmf
Psfr = Pmf + ΔPsf
Psrl = Pmr
Psrr = Pmr + ΔPsr
... (10)

When the departure determination flag Fout is ON and the departure direction Dout is RIGHT, that is, when there is a lane departure tendency with respect to the white line on the right side, the target braking hydraulic pressure Psi (i = i = fl, fr, rl, rr) are calculated.
Psfl = Pmf + ΔPsf
Psfr = Pmf
Psrl = Pmr + ΔPsr
Psrr = Pmr
(11)
According to the equations (10) and (11), the braking force difference between the left and right wheels is generated so that the braking force of the wheel on the lane departure avoidance side is increased.
Further, here, as shown in the equations (10) and (11), the brake operation by the driver, that is, the target brake fluid pressure Psi (i = fl, fr) of each wheel in consideration of the brake fluid pressures Pmf and Pmr. , Rl, rr). Then, the braking / driving force control unit 8 uses the target braking hydraulic pressure Psi (i = fl, fr, rl, rr) calculated for each wheel thus calculated as a braking fluid pressure command value to the braking fluid pressure control unit 7. Output.

(Operation)
The operation is as follows.
While the vehicle is running, various data are read (step S1), and the vehicle speed V and yaw angle are calculated (steps S2 and S3). Subsequently, an estimated lateral displacement (deviation estimated value) Xs is calculated (step S4), and a lane departure tendency is determined (setting of the departure determination flag Fout) based on the calculated estimated lateral displacement Xs. The determination result of the departure tendency (the departure determination flag Fout) is corrected based on the driver's intention to change lanes (step S6).

On the other hand, the reference yaw moment Ms0 is calculated (step S5), and the target yaw moment Ms is calculated by subjecting the calculated reference yaw moment Ms0 to limiter processing (step S8). Further, the control end determination yaw angle φ _end for determining the yaw moment output end timing (end timing of the lane departure prevention control) is determined (step S7), and the vehicle behavior changes according to the lane departure yaw angle φ _depart. Correction is performed based on the response characteristic estimated value α (step S9). Based on the determination result of the lane departure tendency, a warning is output (step S10), and the target braking hydraulic pressure Psi (i = fl, fr, rl, rr) of each wheel is calculated based on the target yaw moment Ms. And the calculated target brake fluid pressure Psi (i = fl, fr, rl, rr) of each wheel is output to the brake fluid pressure controller 7 (step S11). As a result, a yaw moment is applied to the vehicle according to the lane departure tendency of the vehicle. When the yaw moment output end timing is reached (φ _front <φ _end ), the application of the yaw moment to the vehicle is finished, and the lane departure prevention control is finished.

(Function and effect)
The action and effect are as follows.
As described above, the vehicle behavior response characteristic estimated value α is set based on the lane departure yaw angle φ _depart , and the control end determination yaw angle φ _end is corrected based on the set vehicle behavior response characteristic estimated value α. Yes. Specifically, correction is performed to increase the control end determination yaw angle φ _end as the vehicle behavior response characteristic estimated value α increases. Thereby, the yaw moment output end timing by the lane departure prevention control is earlier as the vehicle behavior response characteristic estimated value α is larger. That is, as the vehicle behavior response characteristic estimated value α increases, the yaw moment output by the lane departure prevention control ends at an early stage of the process in which the vehicle returns into the traveling lane.

  Here, the response characteristic of the vehicle behavior to the lane departure prevention control is a response characteristic of the vehicle behavior to the yaw moment application when the yaw moment is applied to the vehicle as the lane departure prevention control, in other words, It can be said that the vehicle is easily affected by the lane departure prevention control or the resistance of the vehicle to the lane departure prevention control. Here, when the response characteristic is high, the vehicle attitude (yaw angle φ) is likely to face in the lane departure avoidance direction, and when the response characteristic is low, the vehicle attitude (yaw angle φ) is difficult to face in the lane departure avoidance direction. . Therefore, even if the same value of yaw moment is applied, if the response characteristics are high, the return amount (yaw angle) of the vehicle to the driving lane will be excessive, or if the response characteristics are low, The amount of return of the vehicle to the lane (yaw angle) may be insufficient. The response characteristics of the vehicle behavior with respect to the lane departure prevention control are easily affected by the vehicle state and the traveling environment when the lane departs, and as a result, the vehicle state and the traveling environment when the lane departs are affected by the lane departure prevention control. It greatly affects the vehicle posture at the end or immediately after the end.

Therefore, based on the lane departure yaw angle _φdepart , the response characteristic of the vehicle behavior to the lane departure prevention control is estimated as the vehicle behavior response characteristic estimated value α, and based on the estimated vehicle behavior response characteristic estimated value α. Thus, by correcting the control end determination yaw angle φ _end , that is, correcting the yaw moment output end timing by the lane departure prevention control, specifically, the yaw moment output increases as the vehicle behavior response characteristic estimated value α increases. By ending the end timing earlier, this makes it possible to obtain a variation in the vehicle orientation (yaw angle) after the end of the lane departure prevention control without being affected by or absorbed by the change in the response characteristic of the vehicle behavior to the lane departure prevention control. Can be suppressed. As a result, the sensation that the vehicle is returned to the driving lane more than necessary by the lane departure prevention control (large feeling of returning), and conversely, the sensation that the vehicle is not returned to the driving lane (sense of lack of control amount). Can be prevented from being given to the driver.

Here, FIG. 11 shows the yaw angle of the vehicle 101 after the end of the lane departure prevention control when the vehicle behavior response characteristic estimation value α (the lane departure yaw angle φ _depart ) is different.
As can be seen from a comparison between (a) and (b) in the figure, even when the vehicle behavior response characteristic estimation value α is different, the vehicle behavior response characteristic estimation value α increases (the lane departure yaw angle φ _depart By reducing the yaw moment output end timing by the lane departure prevention control earlier, the yaw angle (φ _front ) of the vehicle 101 after the lane departure prevention control ends becomes the same value.

Further, as described above, the vehicle behavior response characteristic estimation value α is set based on the lane departure yaw angle _φdepart . Here, as described above, the response characteristic of the vehicle behavior with respect to the lane departure prevention control is easily affected by the vehicle state, the traveling environment, and the like at the time of lane departure. In this embodiment, the yaw angle φ _depart at the time of lane departure is large. It is considered that the response characteristic of the vehicle behavior with respect to the lane departure prevention control becomes lower, becomes less susceptible to the influence of the lane departure prevention control, or the resistance force of the vehicle with respect to the lane departure prevention control increases.
For this reason, by setting the vehicle behavior response characteristic estimated value α based on the lane departure yaw angle φ _depart , the vehicle behavior response characteristic estimated value α is a highly accurate response of the vehicle behavior to the lane departure prevention control. It becomes an index indicating characteristics.

  In the description of the first embodiment, when the processing of FIG. 2 of the braking / driving force control unit 8 determines that the tendency of the vehicle to deviate from the driving lane is high, the vehicle deviates from the driving lane. A control means for starting the lane departure prevention control for preventing the lane departure and for ending the control at a predetermined timing is realized, and the process of step S22 of the braking / driving force control unit 8 is the same as the lane departure prevention control. State detection means for detecting at least one of the vehicle state at the start and the driving environment is realized, and the processing of steps S23 and S24 of the braking / driving force control unit 8 is performed by the vehicle detected by the state detection means. End timing of the lane departure prevention control when the vehicle returns to the traveling lane based on at least one of the state and the traveling environment It is realized a control end timing correction means for correcting the grayed.

  In addition, the process of step S23 of the braking / driving force control unit 8 estimates a response characteristic of the vehicle behavior to the lane departure prevention control based on at least one of the vehicle state and the traveling environment detected by the state detection unit. In response to the response characteristic estimation means, the processing in step S24 of the braking / driving force control unit 8 determines the end timing of the lane departure prevention control based on the response characteristic of the vehicle behavior estimated by the response characteristic estimation means. A control end timing correcting means for correcting is realized.

(Second Embodiment)
Next, a second embodiment will be described.
(Constitution)
Similar to the first embodiment, the second embodiment is a rear wheel drive vehicle equipped with the lane departure prevention apparatus according to the present invention.
In the second embodiment, the processing procedure of the arithmetic processing performed by the braking / driving force control unit 8 is the same as the processing procedure shown in FIG. 2 and is the same processing procedure as in the first embodiment. The criterion for determining the end timing of yaw moment output in step S7 (end timing of lane departure prevention control) is different from that in the first embodiment, and accordingly, correction of the yaw moment output end timing in step S9 is performed. Is different from that of the first embodiment.

That is, in step S7, after the start of the lane departure prevention control, the absolute value of the actual lateral displacement X _front (estimated lateral position Xs when Tt = 0) is referred to as a predetermined value (hereinafter referred to as lateral displacement for determining control end). ) When it is less than X _endin (| X _front | <X _endin ), it is determined that it is the end timing of the lane departure prevention control. And when it determines with it being the completion | finish timing of lane departure prevention control, the departure determination flag Fout is set to OFF.

Figure 12 shows the relationship between the departure-tendency threshold value _{X L} and the control end determination lateral displacement _{X endin.}
As shown in FIG. 12, the control termination determination for the lateral displacement X _Endin is set to the traffic lane inwardly relative departure-tendency threshold value X _L. In addition, by setting in this way, there exists an effect that the hunting of lane departure prevention control can be prevented.
Note that the end timing of the lane departure prevention control may be determined using the estimated lateral position Xs instead of the actual lateral displacement X _front . In this case, when the absolute value of the estimated lateral position Xs is less than the lateral displacement X _endin for control end determination (| Xs | <X _endin ), it is determined that the end timing of the lane departure prevention control is reached.

Basically, the determination based on the lateral displacement X _endin for determining the end of the control ends the lane departure prevention control on the assumption that the lane departure can be avoided, but the displacement to the outside of the lane is predetermined due to a lane change or the like. Even when the value is reached, the lane departure prevention control can be terminated. Control termination determination lateral displacement in this case, as shown in FIG. 12, the X _Endout being positioned in the travel lane outwardly relative departure-tendency threshold value X _L. Thus, the control termination determination for the lateral displacement _{X Endout} value obtained by subtracting the departure-tendency threshold value _{X L} from ls_w_LMT _{(= X endout} -X _L) is, the traffic lane outside of the departure-tendency threshold value _{X L} It becomes the control range of lane departure prevention control.

Incidentally, departure-tendency threshold value X _L and the control end determination lateral displacement X _Endin is displacement relative to the center of the traffic lane, since it is constant irrespective of the lane width, lane width is changed If it would, departure tendency end timing of determining threshold value X _L lane departure prevention control start timing and control end determination lateral displacement X _Endin lane departure prevention control based on based on the lane dividing line forming the driving lane ( With respect to the white line or the like), it changes according to the change in the lane width. For this reason, the threshold value for starting the lane departure prevention control (the threshold value for determining the departure tendency X based on the lane division line (white line or the like)) instead of the displacement amount based on the center of the traveling lane. _L equivalent) and, by setting the lane departure prevention control end determination threshold value (control end determination lateral displacement X _Endin equivalent), lane markings constituting the driving lane (the white line or the like) as a reference, the lane departure Prevention control can be started and ended. This is a difference in geometric expression, and there is no difference in lane departure prevention control.
As described above, the end timing of the lane departure prevention control is determined based on the control end determination lateral displacement _Xendin. Correspondingly, in step S9, the control end determination lateral displacement _Xendin is corrected. is doing.

FIG. 13 shows the processing procedure of step S9.
As shown in FIG. 13, first, as in the first embodiment, in step S21, it is determined whether the vehicle is in a lane departure state (lane departure has started) or not, and in the subsequent step S22, lane departure is determined. The hour yaw angle _φdepart is detected, and in step S23, the vehicle behavior response characteristic estimated value α is set based on the lane departure yaw angle _φdepart .
In the second embodiment, the control end determination lateral displacement _Xendin is corrected (set) in the subsequent step S31 based on the vehicle behavior response characteristic estimated value α set in step S23. Specifically, correction is performed so that the lateral displacement X _endin for control end determination increases as the vehicle behavior response characteristic estimated value α increases.

FIG. 14 shows an example of the relationship between the vehicle behavior response characteristic estimated value α and the control end determination lateral displacement _Xendin .
As shown in FIG. 14, in the region where the vehicle behavior response characteristic estimated value α is small, the control end determination lateral displacement _Xendin is a certain small value, and when the vehicle behavior response characteristic estimated value α is a certain value, control termination determination lateral displacement X _Endin with increasing response characteristic estimated value alpha also increased, then the vehicle behavior response characteristic estimation value and the control end determination lateral displacement _X endin α reaches a certain value and a constant value by a larger value Become. With reference to such a characteristic diagram, the control end determination yaw angle φ _end is corrected (set) based on the vehicle behavior response characteristic estimated value α.

(Operation, action and effect)
Thereby, particularly in the second embodiment, the lateral displacement _Xendin for determining the end of control for determining the end timing of yaw moment output (step S7) is a vehicle behavior response characteristic that changes in accordance with the lane departure yaw angle. Correction is performed based on the estimated value α (step S9). When the yaw moment output end timing comes (| X _front | <X _endin ), the _application of the yaw moment to the vehicle ends, and the lane departure prevention control ends.

  Here, when the response characteristic of the vehicle behavior to the lane departure prevention control is high, the vehicle easily returns into the traveling lane, and when the response characteristic is low, the vehicle does not easily return into the traveling lane. Therefore, even if the yaw moment of the same value is given, if the response characteristic is high, the return amount of the vehicle to the travel lane becomes excessive, or if the response characteristic is low, the vehicle to the travel lane There is a shortage of return amount. The response characteristics of the vehicle behavior with respect to the lane departure prevention control are easily affected by the vehicle state and the traveling environment when the lane departs, and as a result, the vehicle state and the traveling environment when the lane departs are affected by the lane departure prevention control. It greatly affects the vehicle posture at the end or immediately after the end.

Therefore, the response characteristic of the vehicle behavior to the lane departure prevention control is estimated as the vehicle behavior response characteristic estimated value α, and the lateral displacement X _endin for determining the end of the control is _calculated based on the estimated vehicle behavior response characteristic estimated value α. Correction, that is, by correcting the yaw moment output end timing by the lane departure prevention control, specifically, by increasing the yaw moment output end timing as the vehicle behavior response characteristic estimated value α increases, Variations in the amount of return of the vehicle into the traveling lane after the end of the lane departure prevention control can be suppressed without being influenced or absorbed by the change in the response characteristic of the vehicle behavior to the lane departure prevention control.

FIG. 15 shows the yaw angle of the vehicle 101 after the lane departure prevention control is completed when the vehicle behavior response characteristic estimation value α (lane departure yaw angle φ _depart ) is different.
As can be seen from a comparison between (a) and (b) in the figure, even when the vehicle behavior response characteristic estimation value α is different, the vehicle behavior response characteristic estimation value α increases (the lane departure yaw angle φ _depart By reducing the yaw moment output end timing by the lane departure prevention control earlier, the lateral position (X _front ) of the vehicle 101 after the lane departure prevention control ends becomes the same value.

(Third embodiment)
Next, a third embodiment will be described.
(Constitution)
Similar to the first and second embodiments, the third embodiment is a rear wheel drive vehicle equipped with the lane departure prevention apparatus according to the present invention.
In the third embodiment, the processing procedure of the arithmetic processing performed by the braking / driving force control unit 8 is the same as the processing procedure shown in FIG. 2 and is the same processing procedure as in the first embodiment. The correction of the yaw moment output end timing in step S9 is different from that in the first embodiment.
That is, in the third embodiment, in step S9, the yaw moment output end timing is corrected by maintaining (holding) the reference yaw moment Ms0 at the end of the lane departure prevention control for a predetermined time.

FIG. 16 shows the processing procedure of step S9.
As shown in FIG. 16, first, similarly to the first embodiment, in step S21, it is determined whether or not the vehicle is in a deviating state (lane departure has started). The yaw angle _φdepart is detected, and in the subsequent step S23, the vehicle behavior response characteristic estimated value α is set based on the lane departure yaw angle _φdepart .
In the third embodiment, in the following step S41, the yaw moment at the end of the control of the lane departure prevention control (specifically, the target yaw moment) is determined based on the vehicle behavior response characteristic estimated value α set in step S23. Ms0) hold time (hold time) is set.

FIG. 17 shows an example of the relationship between the vehicle behavior response characteristic estimated value α and the holding time T _hold .
As shown in FIG. 17, when the vehicle behavior response characteristic estimated value α is small, a large value becomes a constant value, and when the vehicle behavior response characteristic estimated value α reaches a certain value, the vehicle behavior response characteristic estimated value α increases. On the other hand, when the holding time T _hold decreases and then the vehicle behavior response characteristic estimation value α reaches a certain value, the holding time T _hold becomes a small value and a constant value (T _hold = 0). As a rough outline, as the vehicle behavior response characteristic estimated value α increases, the holding time T _hold decreases (shortens). With reference to such a characteristic diagram, the holding time T _hold is set based on the vehicle behavior response characteristic estimated value α.

Subsequently, in step S42, it is determined whether or not the departure determination flag Fout has changed from ON to OFF. Here, when the departure determination flag Fout is changed from ON to OFF, that is, when it is determined that the end timing of the lane departure prevention control is reached (φ _front <φ _end ), the process proceeds to step S43, and otherwise (the departure determination flag Fout Is maintained ON), the process starts again from step S21.

In step S43, it is determined to _hold the reference yaw moment Ms0 calculated in step S5 for the holding time T _hold set in step S41 ( _{hold the} previous value). Accordingly, the reference yaw moment Ms0 is held by the holding time _{T hold} at which departure judgment flag Fout is turned OFF from ON (the time that satisfies the φ _front <φ _end), the reference yaw moment Ms0 that is held Based on this, a yaw moment is applied to the vehicle.

(Operation, action and effect)
Thus, especially in the third embodiment, when the departure flag Fout is turned OFF from ON, (as the yaw angle reference, phi _front <time filled with phi _{end The)} that point to reduce the reference yaw moment Ms0 of Without any change, the vehicle behavior response characteristic estimation value α is held for the holding time T _{hold and the} yaw moment is applied to the vehicle based on the held reference yaw moment Ms0.

  Here, as described in the first embodiment, when the response characteristic of the vehicle behavior with respect to the lane departure prevention control is high, the vehicle posture (yaw angle φ) is easily oriented in the lane departure avoidance direction, and the response characteristic is When it is low, the vehicle posture (yaw angle φ) is difficult to face in the lane departure avoidance direction. Therefore, even if the same value of yaw moment is applied, if the response characteristics are high, the return amount (yaw angle) of the vehicle to the driving lane will be excessive, or if the response characteristics are low, The amount of return of the vehicle to the lane (yaw angle) may be insufficient. The response characteristics of the vehicle behavior with respect to the lane departure prevention control are easily affected by the vehicle state and the traveling environment when the lane departs, and as a result, the vehicle state and the traveling environment when the lane departs are affected by the lane departure prevention control. It greatly affects the vehicle posture at the end or immediately after the end.

For this reason, the response characteristic of the vehicle behavior to the lane departure prevention control is estimated as the vehicle behavior response characteristic estimated value α, and the holding time T _hold is set based on the estimated vehicle behavior response characteristic estimated value α. The holding time T _hold is reduced as the vehicle behavior response characteristic estimated value α increases. As a result, even if the yaw moment output end timing (φ _front <φ _end ) is originally reached, the vehicle behavior response characteristic estimated value α is applied to the vehicle for the time corresponding to the magnitude thereafter. ing. That is, the end timing of the lane departure prevention control is substantially extended.

  Thereby, it is possible to suppress variations in the vehicle direction (yaw angle) after the end of the lane departure prevention control without being influenced or absorbed by the change in the response characteristic of the vehicle behavior to the lane departure prevention control. As a result, the sensation that the vehicle is returned to the driving lane more than necessary by the lane departure prevention control (large feeling of returning), and conversely, the sensation that the vehicle is not returned to the driving lane (sense of lack of control amount). Can be prevented from being given to the driver.

(Fourth embodiment)
Next, a fourth embodiment will be described.
(Constitution)
The fourth embodiment has basically the same configuration as the third embodiment, but the determination of the end timing of the lane departure prevention control (whether the departure determination flag Fout has changed from ON to OFF). This is different from the third embodiment in that the determination) is performed based on the lateral displacement.
That is, in the step S7, after the start of the lane departure prevention control, when the absolute value estimation of the actual lateral displacement X _{front or} the absolute value of the constant lateral position Xs _becomes less than the lateral displacement X _endin for control end determination (| X _front | <X _endin or | Xs | <X _endin ), and the end timing of the lane departure prevention control is determined. And when it determines with it being the completion | finish timing of lane departure prevention control, the departure determination flag Fout is set to OFF.
Further, the end timing of the lane departure prevention control in step S9 is also determined based on the lateral displacement.

FIG. 18 shows the processing procedure of step S9.
As shown in FIG. 18, first, similarly to the third embodiment, in step S21, it is determined whether or not the vehicle is in a deviating state (lane departure has started). The yaw angle _φdepart is detected. In the subsequent step S23, the vehicle behavior response characteristic estimated value α is set based on the lane departure yaw angle _φdepart , and in the subsequent step S41, the vehicle behavior response characteristic estimation set in the step S23 is set. Based on the value α, the yaw moment holding time at the end of the lane departure prevention control is set.

In the fourth embodiment, in the subsequent step S51, it is determined whether or not the departure determination flag Fout has changed from ON to OFF based on the lateral displacement. That is, if | X _front | <X _endin or | Xs | <X _endin , the departure determination flag Fout is changed from ON to OFF, that is, it is determined as the end timing of the lane departure prevention control, and the _{process proceeds} to step S43. If not, the process starts again from step S21.

In step S43, as in the third embodiment, it is determined to _hold the reference yaw moment Ms0 calculated in step S5 for the holding time T _hold set in step S41 ( _{hold the} previous value). As a result, the reference yaw moment Ms0 at the time when the deviation determination flag Fout is changed from ON to OFF (when | X _front | <X _endin or | Xs | <X _endin is satisfied) is held for the holding time T _hold , A yaw moment is applied to the vehicle based on the retained reference yaw moment Ms0.

(Operation, action and effect)
Thus, particularly in the fourth embodiment, when the departure determination flag Fout is changed from ON to OFF, at that time (when the lateral displacement criterion satisfies | X _front | <X _endin or | Xs | <X _endin ) Without reducing the reference yaw moment Ms0, and holding the holding time T _hold corresponding to the vehicle behavior response characteristic estimated value α as it is, and giving the vehicle a yaw moment based on the held reference yaw moment Ms0. To do.

  Here, as described in the second embodiment, when the response characteristic of the vehicle behavior to the lane departure prevention control is high, the vehicle easily returns to the traveling lane, and when the response characteristic is low, the vehicle travels. The vehicle is difficult to return to the lane. Therefore, even if the yaw moment of the same value is given, if the response characteristic is high, the return amount of the vehicle to the travel lane becomes excessive, or if the response characteristic is low, the vehicle to the travel lane There is a shortage of return amount. The response characteristics of the vehicle behavior with respect to the lane departure prevention control are easily affected by the vehicle state and the traveling environment when the lane departs, and as a result, the vehicle state and the traveling environment when the lane departs are affected by the lane departure prevention control. It greatly affects the vehicle posture at the end or immediately after the end.

For this reason, the response characteristic of the vehicle behavior to the lane departure prevention control is estimated as the vehicle behavior response characteristic estimated value α, and the holding time T _hold is set based on the estimated vehicle behavior response characteristic estimated value α. The holding time T _hold is reduced as the vehicle behavior response characteristic estimated value α increases. As a result, even if the yaw moment output end timing (φ _front <φ _end ) is originally reached, the vehicle behavior response characteristic estimated value α is applied to the vehicle for the time corresponding to the magnitude thereafter. ing. That is, the end timing of the lane departure prevention control is substantially extended.

  Thereby, it is possible to suppress variations in the amount of return of the vehicle into the traveling lane after completion of the lane departure prevention control without being influenced or absorbed by the change in the response characteristic of the vehicle behavior to the lane departure prevention control. . As a result, the sensation that the vehicle is returned to the driving lane more than necessary by the lane departure prevention control (large feeling of returning), and conversely, the sensation that the vehicle is not returned to the driving lane (sense of lack of control amount). Can be prevented from being given to the driver.

(Fifth embodiment)
Next, a fifth embodiment will be described.
(Constitution)
In the fifth embodiment, the vehicle behavior response characteristic estimated value α in step S9 is set based on the vehicle speed V, and this point is different from the first to fourth embodiments.
FIG. 19 shows the processing procedure of step S9 in the fifth embodiment.
As shown in FIG. 19, first, in the same manner as in the first embodiment, in step S21, it is determined whether or not the vehicle is in a departure state (whether or not a lane departure has started). Proceed to step S61.

In the fifth embodiment, the vehicle speed _Vdepart is detected in step S61. This step S61 is a step that proceeds when it is determined in step S21 that the vehicle is in a lane departure state. Therefore, the vehicle speed detected in step S61 is the vehicle speed at the time of lane departure determination.
Subsequently, in step S23, a vehicle behavior response characteristic estimated value α is set based on the vehicle speed detected in step S61 (hereinafter referred to as lane departure vehicle speed) _Vdepart . Specifically, the vehicle behavior response characteristic estimated value α is decreased as the lane departure vehicle speed _Vdepart increases.

FIG. 20 shows an example of the relationship between the lane departure vehicle speed _Vdepart and the vehicle behavior response characteristic estimated value α.
As shown in FIG. 20, the vehicle behavior response characteristic estimated value α decreases in a quadratic function as the vehicle speed _Vdepart at the time of lane departure increases. With reference to such a characteristic diagram, the vehicle behavior response characteristic estimated value α is set based on the vehicle speed _Vdepart at the time of lane departure.
Subsequently, in step S24, as in the first embodiment, based on the vehicle behavior response characteristic estimated value α set in step S23, the control end determination used for determining the end of the lane departure prevention control in step S7. the use yaw angle φ _end to correction (set).

(Operation, action and effect)
As described above, particularly in the fifth embodiment, the control end determination yaw angle φ _end for determining the yaw moment output end timing (step S7), and the vehicle behavior that changes according to the lane departure vehicle speed _Vdepart. Correction is made based on the response characteristic estimated value α (step S9, FIG. 19).
Here, as the vehicle speed _Vdepart at the time of departure from the lane decreases, the straight-line restoring force of the vehicle that counteracts the yaw moment applied to the vehicle by the lane departure prevention control becomes weaker, and the response of the vehicle behavior to the lane departure prevention control. It is considered that the characteristics are improved.
For this reason, by setting the vehicle behavior response characteristic estimated value α based on the vehicle speed _Vdepart at the time of lane departure, the vehicle behavior response characteristic estimated value α can be obtained with high accuracy. It becomes the index which shows.

FIG. 21 shows the yaw angle of the vehicle 101 after the lane departure prevention control ends when the lane departure vehicle speed _Vdepart (vehicle behavior response characteristic estimated value α) is different.
As can be seen from a comparison between (a) and (b) in the figure, even when the lane departure vehicle speed _Vdepart (vehicle behavior response characteristic estimation value α) is different, the lane departure vehicle speed _Vdepart decreases. By making the yaw moment output end timing by the lane departure prevention control earlier, the yaw angle (φ _front ) of the vehicle 101 after the lane departure prevention control ends becomes the same value.

(Sixth embodiment)
Next, a sixth embodiment will be described.
(Constitution)
In the sixth embodiment, the vehicle behavior response characteristic estimated value α in step S9 is set based on the road radius (1 / β), which is different from the case of the fifth embodiment. .
FIG. 22 shows the processing procedure of step S9 in the sixth embodiment.
As shown in FIG. 22, first, in the same manner as in the fifth embodiment, in step S21, it is determined whether or not the vehicle is in a deviating state (whether the lane departure has started). Proceed to step S71.

In the sixth embodiment, in step S71, a road radius (hereinafter referred to as a lane departure road radius) _Rdepart is detected.
Subsequently, in step S23, a vehicle behavior response characteristic estimated value α is set based on the lane departure road radius _Rdepart detected in step S71. Specifically, the vehicle behavior response characteristic estimated value α is increased as the lane departure road radius _Rdepart increases.

FIG. 23 shows an example of the relationship between the road radius _Rdepart at the time of lane departure and the vehicle behavior response characteristic estimated value α.
As shown in FIG. 23, the vehicle behavior response characteristic estimated value α increases in a quadratic function with the road radius _Rdepart at the time of lane departure. With reference to such a characteristic diagram, the vehicle behavior response characteristic estimation value α is set based on the road radius _Rdepart at the time of lane departure.
Subsequently, in step S24, similarly to the fifth embodiment, based on the vehicle behavior response characteristic estimated value α set in step S23, the control end determination used for determining the end of the lane departure prevention control in step S7. the use yaw angle φ _end to correction (set).

(Operation, action and effect)
Thus, particularly in the sixth embodiment, the control end determination yaw angle φ _end for determining the yaw moment output end timing (step S7), and the vehicle changes in accordance with the lane departure road radius _Rdepart. Correction is performed based on the behavior response characteristic estimated value α (step S9, FIG. 22).
Here, as the road radius _Rdepart at the time of lane departure increases, the centrifugal force of the vehicle that counteracts the yaw moment applied to the vehicle by the lane departure prevention control becomes weaker, and the response of the vehicle behavior to the lane departure prevention control It is considered that the characteristics are improved.
For this reason, by setting the vehicle behavior response characteristic estimated value α based on the road radius _Rdepart at the time of lane departure, the vehicle behavior response characteristic estimated value α can be obtained as a response of the vehicle behavior to the lane departure prevention control with high accuracy. It becomes an index indicating characteristics.

FIG. 24 shows the yaw angle of the vehicle 101 after the lane departure prevention control ends when the lane departure road radius _Rdepart (vehicle behavior response characteristic estimated value α) is different.
As can be seen from a comparison of (a) and (b) in the figure, even when the road lane departure radius R _depart (vehicle behavior response characteristic estimation value α) is different, the lane departure road radius R _depart is large. The yaw angle (φ _front ) of the vehicle 101 after the end of the lane departure prevention control becomes a similar value by increasing the yaw moment output end timing by the lane departure prevention control.

(Seventh embodiment)
Next, a seventh embodiment will be described.
(Constitution)
In the seventh embodiment, the vehicle behavior response characteristic estimated value α in step S9 is set based on the degree of road surface cant (inclination in the lane width direction), which is the fifth and sixth implementations. It is different from the case of form.
FIG. 25 shows the processing procedure of step S9 in the seventh embodiment.
As shown in FIG. 25, first, similarly to the fifth and sixth embodiments, in step S21, it is determined whether or not the vehicle is in a deviating state (lane departure has started). If yes, the process proceeds to step S81.

In the seventh embodiment, in step S81, a road surface cant degree (hereinafter referred to as a lane departure cant degree) _Cdepart is detected. Here, the detection of the degree of the road surface cant may be performed by a generally used method. For example, the degree of road surface cant is estimated based on the difference between the steering value and the yaw rate value, the degree of road surface cant is estimated based on the road radius (it is estimated that the smaller the road radius, the more inside the turn is inclined), navigation The degree of the road surface cant may be estimated based on the information.

  Further, in this embodiment, the road surface cant degree is set to 0 when the vehicle is not inclined in the lane width direction, and the side where the vehicle deviates from the lane in the width direction of the traveling lane is an up cant (the lane center If the vehicle departs from the lane is high), the vehicle is increased by a positive value according to the degree of inclination, and if the vehicle deviates from the lane in the width direction of the traveling lane, it is descended to the lane (lane) When the vehicle departs from the lane with respect to the center is low), the value is decreased by a negative value according to the degree of inclination.

Subsequently, in step S23, a vehicle behavior response characteristic estimated value α is set based on the lane departure time road surface cant degree _Cdepart detected in step S81. Specifically, the vehicle behavior response characteristic estimation value α increases as the road surface cant degree C _depart at the time of departure from the lane increases (the tendency that the side where the vehicle departs from the lane in the width direction of the traveling lane tends to rise). To do.

FIG. 26 shows an example of the relationship between the lane departure road surface cant degree _Cdepart and the vehicle behavior response characteristic estimated value α.
As shown in FIG. 26, the vehicle behavior response characteristic estimated value α increases in a quadratic function with the lane departure road surface cant degree _Cdepart . With reference to such a characteristic diagram, the vehicle behavior response characteristic estimated value α is set based on the road surface cant degree C at the time of lane departure.
Subsequently, in step S24, similarly to the fifth and sixth embodiments, based on the vehicle behavior response characteristic estimated value α set in step S23, it is used for determining the end of the lane departure prevention control in step S7. The control end determination yaw angle _φend is corrected (set).

(Operation, action and effect)
Thus, particularly in the seventh embodiment, the control end determination yaw angle φ _end for determining the yaw moment output end timing (step S7) is changed according to the lane departure road surface cant degree C. Correction is performed based on the behavior response characteristic estimated value α (step S9, FIG. 25).
Here, as the lane departure road surface cant degree _Cdepart increases, the force acting on the vehicle to return the vehicle to the center of the lane increases, that is, the yaw moment applied to the vehicle by the lane departure prevention control Since the force acting in the same direction becomes large, it is considered that the response characteristic of the vehicle behavior to the lane departure prevention control becomes high.
For this reason, by setting the vehicle behavior response characteristic estimated value α based on the lane departure road surface cant degree C _depart , the vehicle behavior response characteristic estimated value α can be obtained with high accuracy. It becomes an index indicating response characteristics.

FIG. 27 shows the yaw angle of the vehicle 101 after the lane departure prevention control is completed when the road surface cant degree C _depart (vehicle behavior response characteristic estimated value α) at the time of lane departure is different.
As can be seen from a comparison between (a) and (b) of the figure, even when the lane departure road surface cant degree C _depart (vehicle behavior response characteristic estimation value α) is different, the lane departure road surface cant degree C _depart. By increasing the yaw moment output end timing by the lane departure prevention control, the yaw angle (φ _front ) of the vehicle 101 after the end of the lane departure prevention control becomes a similar value.

(Eighth embodiment)
Next, an eighth embodiment will be described.
(Constitution)
In the eighth embodiment, the vehicle behavior response characteristic estimated value α in step S9 is set based on the road surface friction coefficient. This is different from the fifth to seventh embodiments.
FIG. 28 shows the processing procedure of step S9 in the eighth embodiment.
As shown in FIG. 28, first, similarly to the fifth to seventh embodiments, in step S21, it is determined whether or not the vehicle is in a deviating state (whether lane departure has started), and the deviating state is entered. If yes, the process proceeds to step S91.

In the eighth embodiment, in step S91, a road surface friction coefficient (hereinafter, referred to as a lane departure road surface friction coefficient) _μdepart is detected. Here, the detection of the road surface friction coefficient may be performed by a generally used technique. For example, the road surface friction coefficient may be estimated from a change in wheel speed or a difference value between the target vehicle speed and the actual vehicle speed.
Subsequently, in step S23, a vehicle behavior response characteristic estimated value α is set based on the lane departure road surface friction coefficient μ _depart detected in step S91. Specifically, the vehicle behavior response characteristic estimated value α is decreased as the lane departure road surface friction coefficient μ _depart increases.

FIG. 29 shows an example of the relationship between the lane departure road surface friction coefficient μ _depart and the vehicle behavior response characteristic estimated value α.
As shown in FIG. 29, the vehicle behavior response characteristic estimated value α increases in a quadratic function with the road surface friction coefficient μ _depart at the time of lane departure. With reference to such a characteristic diagram, the vehicle behavior response characteristic estimated value α is set based on the road surface friction coefficient μ _depart at the time of lane departure.
Subsequently, in step S24, as in the fifth to seventh embodiments, based on the vehicle behavior response characteristic estimated value α set in step S23, it is used to determine the end of the lane departure prevention control in step S7. The control end determination yaw angle _φend is corrected (set).

(Operation, action and effect)
Thus, particularly in the eighth embodiment, the control end determination yaw angle φ _end for determining the yaw moment output end timing (step S7) changes according to the lane departure road surface friction coefficient μ _depart. Correction is performed based on the vehicle behavior response characteristic estimated value α (step S9, FIG. 28).
Here, as the road surface friction coefficient μ _depart at the time of departure from the lane increases, the degree of slip between the road surface and the wheel decreases, so that the yaw moment applied to the vehicle by the lane departure prevention control can be brought close to the target value. It is considered that the response characteristic of the vehicle behavior with respect to the departure prevention control becomes high.
For this reason, by setting the vehicle behavior response characteristic estimated value α based on the road surface friction coefficient μ _depart at the time of lane departure, the vehicle behavior response characteristic estimated value α can be obtained with a high degree of accuracy. It becomes an index indicating response characteristics.

(Ninth embodiment)
Next, a ninth embodiment will be described.
(Constitution)
The ninth embodiment is a rear-wheel drive vehicle equipped with the lane departure prevention apparatus according to the present invention, as in the first to eighth embodiments.
In the ninth embodiment, the yaw moment output end timing (end timing of the lane departure prevention control) corrected based on the vehicle behavior response characteristic estimated value α (such as the lane departure yaw angle φ _depart ) is used as the driving operation of the driver. Further correction based on the state.

FIG. 30 shows a calculation process performed by the braking / driving force control unit 8 of the ninth embodiment.
The basic part of the arithmetic processing performed by the braking / driving force control unit 8 of the ninth embodiment shown in FIG. 30 is the same as the arithmetic processing shown in FIG. 2, but in FIG. 30 in the ninth embodiment. In the calculation process shown, in particular, step S101 and step S102 are provided after step S9. In the following description, in the arithmetic processing shown in FIG. 30 in the ninth embodiment, the same reference numerals as those in the arithmetic processing shown in FIG. 2 in the first embodiment are the same unless otherwise specified. It is.

As shown in FIG. 30, in step S101, a driving operation state is detected. Specifically, as shown in (12) below, the amount of change (steering angle) within a predetermined time Tstr1 (for example, 0.2 seconds) of the steering angle δ (detected value of the steering angle sensor 19) read in step S1. The steering speed Δstr is calculated based on the difference between the current value δnow of δ and the value δtstr before a predetermined time.
Δstr = | (δnow−δtstr) / Tstr | (12)
Subsequently, in step S102, the yaw moment output end timing corrected in step S9 is further corrected based on the driving operation state.

FIG. 31 shows the processing procedure.
As shown in FIG. 31, first, in step S111, a steering determination threshold value Δstr_th for comparison with the steering speed Δstr calculated in step S101 is set. The steering determination threshold value Δstr_th is, for example, an experimental value or an empirical value, and is a value with which it can be determined that the driver has performed a steering operation.
In step S112, the steering speed Δstr calculated in step S101 is compared with the steering determination threshold value Δstr_th. If the steering speed Δstr is less than or equal to the steering determination threshold value Δstr_th (Δstr ≦ Δstr_th), the process proceeds to step S113. Otherwise (Δstr> Δstr_th), the process proceeds to step S114.

In step S113, it is determined to maintain the yaw moment output end timing corrected based on the vehicle behavior response characteristic estimated value α. In step S114, the yaw moment output end timing corrected based on the vehicle behavior response characteristic estimated value α is determined. Make further corrections. In step S114, specifically, the control end determination yaw angle φ _end , the control end determination lateral displacement X _endin or the holding time T _hold corrected based on the vehicle behavior response characteristic estimated value α is set to the maximum vehicle behavior. By returning to the control end determination yaw angle φ _end , the control end determination lateral displacement X _endin or the holding time T _hold corresponding to the response characteristic estimation value α (see FIGS. 10, 14, and 17), the yaw moment output Make corrections to restore the end timing.

  As a result, even when correction is made so that the yaw moment output end timing is delayed based on the vehicle behavior response characteristic estimated value α in step S9, the change amount of the steering angle δ or the steering speed can be determined in steps S101 and S102. Is large, it is assumed that the driver has an intention to drive (the driver has a high intention to drive), and the corrected yaw moment output end timing is corrected again in an earlier direction, that is, vehicle behavior response characteristics. Correction of the yaw moment output end timing based on the estimated value α is suppressed.

As a result, when the driver intends to perform a driving operation, it is possible to prevent the lane departure prevention control from causing trouble for the driver by increasing the operation time of the lane departure prevention control.
In addition, the said embodiment can also be implement | achieved by the following structures.
That is, in step S101 of the ninth embodiment, the steering speed Δstr2 is calculated based on the steering change amount within a longer time Tstr2 (> Tstr1, for example, 2 seconds) in response to a slower steering operation. (Equation (13) below).
Δstr2 = | (δnow−δtstr2) / Tstr2 | (13)
Here, δtstr2 is the steering angle δ before time Tstr2.

  In the ninth embodiment, the steering speed Δstr is calculated based on the steering angle δ, and the calculated steering speed Δstr is compared with the steering determination threshold value Δstr_th to determine the driver's intention to drive. is doing. On the other hand, in addition to the steering determination threshold value (hereinafter referred to as the first steering determination threshold value) Δstr_th, a second steering determination threshold value Δstr_th2 may be provided. In this case, the second steering determination threshold value Δstr_th2 is set to a value larger than the first steering determination threshold value Δstr_th (Δstr_th2> Δstr_th), and the steering speed Δstr is the second steering determination threshold value. If the value Δstr_th2 or less (Δstr ≦ Δstr_th2), it is determined to maintain the yaw moment output end timing corrected based on the vehicle behavior response characteristic estimated value α. If not (Δstr> Δstr_th2), the vehicle behavior response characteristic estimated value It is determined to further correct the yaw moment output end timing corrected based on α.

  In addition, the driver's intention to drive can be determined based on the amount of change in accelerator opening (for example, accelerator operation speed) Δθ and the amount of change in brake operation (for example, brake operation speed) ΔBrk. That is, the accelerator operation state and the brake operation state can be used as an index for determining the driver's intention to drive. In this case, the accelerator operation state is detected by the accelerator opening sensor 18, and the brake operation state is detected by the brake operation sensor.

In this case, for example, the change amount Δθ of the accelerator opening is calculated as in the following equation (14), and the change amount ΔBrk of the brake operation is calculated as in the following equation (15).
Δθ = | (θnow−θtθ) / Tθ | (14)
ΔBrk = | (Brknow−Brktbrk) / TBrk | (15)
Here, θnow is the current value of the accelerator opening θ, and θtθ is the accelerator opening θ before a predetermined time Tθ. Brknow is the current value of the brake operation position Brk, and Brktbrk is the brake operation position Brk before the predetermined time TBrk.

  Further, by obtaining a plurality of indicators for determining the driver's intention to drive, for example, obtaining the aforementioned Δstr, Δstr2, Δθ, ΔBrk, and further correcting the yaw moment output end timing based on each indicator for determination. You can also. In this way, the optimum yaw moment output end timing can be achieved by referring to the determination index of the driving operation intention of a plurality of drivers.

Moreover, in the said embodiment, a yaw angle etc. are mentioned and demonstrated concretely as a value which shows a vehicle state or driving environment. On the other hand, the vehicle state and the traveling environment can be set to other values.
Further, the present invention is not limited to the application of the yaw moment by the braking control, and for example, the yaw moment may be applied by the application of the driving force difference between the left and right wheels or the steering control.

1 is a schematic configuration diagram illustrating a vehicle according to a first embodiment of the present invention. It is a flowchart which shows the processing content of the control unit of the lane departure prevention apparatus of a vehicle. It is a diagram used for explanation of the estimated lateral displacement Xs and the departure tendency determination threshold value X _L. It is a characteristic view which shows the relationship between the vehicle speed V and the gain K2. FIG. 6 is a characteristic diagram showing a change with time of a reference yaw moment Ms0. It is a characteristic view which shows the time-dependent change of the target yaw moment Ms obtained by the limiter process. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the said control unit. FIG. 6 is a characteristic diagram showing a relationship between a lane departure yaw angle _φdepart and a vehicle behavior response characteristic estimated value α. It is the figure used for description of the relationship between yaw angle (phi) depart and vehicle behavior response characteristic estimated value (alpha). FIG. 7 is a characteristic diagram showing a relationship between a vehicle behavior response characteristic estimated value α and a control end determination yaw angle φ _end . It is the figure used for description of the effect in 1st Embodiment. It is a characteristic diagram showing the relationship between the departure-tendency threshold value X _L and the control end determination lateral displacement _X endin. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 2nd Embodiment. It is a characteristic view which shows the relationship between the vehicle behavior response characteristic estimated value (alpha) and the lateral displacement _Xendin for control completion determination. It is the figure used for description of the effect in 2nd Embodiment. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 3rd Embodiment. It is a characteristic view which shows the relationship between vehicle behavior response characteristic estimated value (alpha) and holding _| maintenance time _Thold . It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 4th Embodiment. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 5th Embodiment. FIG. 6 is a characteristic diagram showing a relationship between a vehicle speed _Vdepart at the time of lane departure and a vehicle behavior response characteristic estimated value α. It is the figure used for description of the effect in 5th Embodiment. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 6th Embodiment. FIG. 6 is a characteristic diagram showing the relationship between a road radius _Rdepart at the time of lane departure and a vehicle behavior response characteristic estimated value α. It is the figure used for description of the effect in 6th Embodiment. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 7th Embodiment. It is a characteristic view showing the relationship between the road surface cant degree _Cdepart at the time of lane departure and the vehicle behavior response characteristic estimated value α. It is the figure used for description of the effect in 7th Embodiment. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing by the control unit in 8th Embodiment. FIG. 6 is a characteristic diagram showing a relationship between a road surface friction coefficient μ _depart and a vehicle behavior response characteristic estimated value α when departing from a lane. It is a flowchart which shows the processing content of the control unit in 9th Embodiment. It is a flowchart which shows the processing content of the correction process of the yaw moment output completion timing based on a driving | running operation state by the control unit in 9th Embodiment.

Explanation of symbols

  6FL to 6RR wheel cylinder, 7 braking fluid pressure control unit, 8 braking / driving force control unit, 9 engine, 12 driving torque control unit, 13 imaging unit, 17 master cylinder pressure sensor, 18 accelerator opening sensor, 19 steering angle sensor, 22FL-22RR Wheel speed sensor

Claims (11)

Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting a yaw angle formed by the traveling lane and the vehicle at the start of the lane departure prevention control;
Control end timing correction means for accelerating the end timing of the lane departure prevention control when the vehicle returns to the travel lane, as the yaw angle detected by the state detection unit at the start of the lane departure prevention control decreases .
Equipped with a,
The control means ends the lane departure prevention control when the yaw angle formed by the traveling lane and the vehicle returns to a predetermined yaw angle after the lane departure prevention control starts.
The control end timing correcting means increases the predetermined yaw angle as the yaw angle formed between the travel lane and the vehicle at the start of the lane departure prevention control becomes smaller, thereby ending the lane departure prevention control. A lane departure prevention device characterized by speeding up the vehicle. Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting a yaw angle formed by the traveling lane and the vehicle at the start of the lane departure prevention control;
Control end timing correction means for accelerating the end timing of the lane departure prevention control when the vehicle returns to the travel lane, as the yaw angle detected by the state detection unit at the start of the lane departure prevention control decreases .
Equipped with a,
The control means terminates the lane departure prevention control when the lateral displacement amount of the vehicle with respect to the traveling lane returns to a predetermined displacement amount after the lane departure prevention control starts,
Before SL control end timing correcting means, wherein as the yaw angle formed between the traveling lane and the vehicle at the start of lane departure prevention control is reduced, by increasing the predetermined amount of displacement, the end of the lane departure prevention control A lane departure prevention device characterized in that the timing is advanced . Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting a vehicle speed at the start of the lane departure prevention control;
Control end timing correction means for accelerating the end timing of the lane departure prevention control when the vehicle returns to the travel lane, as the vehicle speed detected at the start of the lane departure prevention control by the state detection unit decreases .
Equipped with a,
The control means ends the lane departure prevention control when the yaw angle formed by the traveling lane and the vehicle returns to a predetermined yaw angle after the lane departure prevention control starts.
The control end timing correction means makes the end timing of the lane departure prevention control earlier by increasing the predetermined yaw angle as the vehicle speed at the start of the lane departure prevention control decreases. Lane departure prevention device. Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting a vehicle speed at the start of the lane departure prevention control;
Control end timing correction means for accelerating the end timing of the lane departure prevention control when the vehicle returns to the travel lane, as the vehicle speed detected at the start of the lane departure prevention control by the state detection unit decreases .
Equipped with a,
The control means terminates the lane departure prevention control when the lateral displacement amount of the vehicle with respect to the traveling lane returns to a predetermined displacement amount after the lane departure prevention control starts,
Before SL control end timing correction means, as the vehicle speed at the start of the lane departure prevention control is reduced, by increasing the predetermined amount of displacement, and characterized in that to speed up completion timing of the lane departure prevention control Lane departure prevention device. Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting a road radius of the travel lane at the start of the lane departure prevention control;
Control end timing correction means for increasing the end timing of the lane departure prevention control when the vehicle returns to the travel lane , as the road radius detected by the state detection unit at the start of the lane departure prevention control increases .
Equipped with a,
The control means ends the lane departure prevention control when the yaw angle formed by the traveling lane and the vehicle returns to a predetermined yaw angle after the lane departure prevention control starts.
The control end timing correction means increases the predetermined yaw angle as the road radius at the start of the lane departure prevention control increases, thereby accelerating the end timing of the lane departure prevention control. Lane departure prevention device. Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting a road radius of the travel lane at the start of the lane departure prevention control;
Control end timing correction means for increasing the end timing of the lane departure prevention control when the vehicle returns to the travel lane , as the road radius detected by the state detection unit at the start of the lane departure prevention control increases .
Equipped with a,
The control means terminates the lane departure prevention control when the lateral displacement amount of the vehicle with respect to the traveling lane returns to a predetermined displacement amount after the lane departure prevention control starts,
Before SL control end timing correcting means, wherein the road radius at the start of lane departure prevention control is larger, by increasing the predetermined amount of displacement, characterized in that to speed up completion timing of the lane departure prevention control A lane departure prevention device. Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting the degree of inclination of the outer position where the vehicle departs from the lane relative to the center position in the traveling lane at the start of the lane departure prevention control;
The lane departure when the vehicle returns to the traveling lane increases as the degree of the inclination detected at the start of the lane departure prevention control by the state detection unit increases in the direction in which the outer position becomes higher than the central position. Control end timing correction means for accelerating the end timing of prevention control;
Equipped with a,
The control means ends the lane departure prevention control when the yaw angle formed by the traveling lane and the vehicle returns to a predetermined yaw angle after the lane departure prevention control starts.
The control end timing correction means increases the predetermined yaw angle as the degree of inclination at the start of the lane departure prevention control increases in the direction in which the outer position increases with respect to the center position. A lane departure prevention apparatus characterized in that the lane departure prevention control end timing is advanced . Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detecting means for detecting the degree of inclination of the outer position where the vehicle departs from the lane relative to the center position in the traveling lane at the start of the lane departure prevention control;
The lane departure when the vehicle returns to the traveling lane increases as the degree of the inclination detected at the start of the lane departure prevention control by the state detection unit increases in the direction in which the outer position becomes higher than the central position. Control end timing correction means for accelerating the end timing of prevention control;
Equipped with a,
The control means terminates the lane departure prevention control when the lateral displacement amount of the vehicle with respect to the traveling lane returns to a predetermined displacement amount after the lane departure prevention control starts,
Before SL control end timing correction means, the degree of the inclination at the start of the lane departure prevention control, the greater the direction outer position is increased relative to the center position, increasing the predetermined amount of displacement Thus, the lane departure prevention apparatus is characterized in that the lane departure prevention control end timing is advanced . Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detection means for detecting a road surface friction coefficient at the start of the lane departure prevention control;
Control end timing correction means for increasing the end timing of the lane departure prevention control when the vehicle returns to the traveling lane , as the road surface friction coefficient detected by the state detection unit at the start of the lane departure prevention control increases .
Equipped with a,
The control means ends the lane departure prevention control when the yaw angle formed by the traveling lane and the vehicle returns to a predetermined yaw angle after the lane departure prevention control starts.
The control end timing correction means increases the predetermined yaw angle as the road surface friction coefficient at the start of the lane departure prevention control increases, thereby accelerating the end timing of the lane departure prevention control. A lane departure prevention device. Control means for starting the lane departure prevention control for preventing the vehicle from deviating from the traveling lane and determining that the control is terminated at a predetermined timing when it is determined that the vehicle has a tendency to deviate from the traveling lane. When,
State detection means for detecting a road surface friction coefficient at the start of the lane departure prevention control;
Control end timing correction means for increasing the end timing of the lane departure prevention control when the vehicle returns to the traveling lane , as the road surface friction coefficient detected by the state detection unit at the start of the lane departure prevention control increases .
Equipped with a,
The control means terminates the lane departure prevention control when the lateral displacement amount of the vehicle with respect to the traveling lane returns to a predetermined displacement amount after the lane departure prevention control starts,
Before SL control end timing correction means increases the road surface friction coefficient at the start of the lane departure prevention control, by increasing the predetermined amount of displacement, to quickly end timing of the lane departure prevention control A characteristic lane departure prevention device. Further provided is a driving operation intention detecting means for detecting the driving operation intention of the driver based on the driving operation state of the driver, and the control end timing correcting means detects the driving operation intention of the driver by the driving operation intention detecting means. The lane departure prevention apparatus according to any one of claims 1 to 10 , wherein, when the lane departure prevention control is performed, correction of an end timing of the lane departure prevention control is suppressed.

Images