JP4396514B2 - Lane departure prevention device - Google Patents

Description

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

  Conventionally, this type of technology includes, for example, estimating a near-future travel trajectory of the host vehicle, and superimposing the estimated travel trajectory and the shape of the travel lane of the host vehicle so that the host vehicle Determining whether there is a possibility of deviating from the vehicle, operating the steering actuator when there is a possibility of deviating, and applying auxiliary steering force in a direction to avoid the deviation, thereby preventing deviation from the lane Has been proposed (see, for example, Patent Document 1).

In addition, regardless of the driver's steering operation, the braking force actuator is controlled according to the lateral deviation amount of the traveling position of the host vehicle, and the braking force is applied to the wheel on the opposite side to the departure direction of the left and right wheels. There have also been proposed ones that prevent deviation from the lane (see, for example, Patent Document 2).
JP-A-9-142327 JP 2000-33860 A

Here, in the above-described conventional method, it is determined whether to apply an auxiliary steering force or a braking force for avoiding a departure based on the traveling locus of the own vehicle with respect to the traveling lane or the traveling position of the own vehicle. I have to. For this reason, when the driver performs a deviation avoidance operation by steering while performing various controls for avoiding deviation, the vehicle posture change in the deviation avoidance direction caused by the control for avoiding deviation is generated. And the vehicle attitude change in the departure avoidance direction due to the driver's operation overlaps, and in some cases, the driver feels excessive control, or feels that the driver is returning too much in the lane departure avoidance direction. There is a problem that it may give an uncomfortable feeling.
Therefore, the present invention has been made paying attention to the above-mentioned conventional problem, and when a driver's departure avoidance operation is performed while control intervention by departure avoidance control is being performed, driving is performed. An object of the present invention is to provide a lane departure prevention device capable of suppressing excessive feeling of control given to a person.

In order to achieve the above object, the lane departure prevention apparatus according to the present invention performs vehicle behavior control by the departure avoidance control means so as to avoid the departure when the host vehicle tends to depart from the traveling lane. .
At this time, a steering angle detecting means for detecting a steering angle, and a steering angle holding means for holding a steering angle at the start of control, which is a steering angle detected by the steering angle detecting means at the start of control intervention by the departure avoidance control means. And the detected steering angle detected by the steering angle detecting means is within an angular range in a direction that avoids deviation from the steering angle at the start of control held by the steering angle holding means. When the deviation avoidance operation detecting means for detecting that the driver is performing an operation for avoiding the deviation is detected, the control avoidance by the deviation avoidance control means is avoided. The vehicle is generated by the control amount correction means so that the control amount becomes smaller than that when the driver is not detected to be performing the departure avoidance operation, that is, by the departure avoidance control. Corrected to energize the change is small.

According to the lane departure prevention apparatus according to the present invention, a steering angle detection unit that detects a steering angle, and a control start time that is a steering angle detected by the steering angle detection unit at the start of control intervention by the departure avoidance control unit. Steering angle holding means for holding the steering angle, and the detected steering angle detected by the steering angle detecting means avoids deviation from the steering angle at the start of control held by the steering angle holding means. When it is detected that the driver is performing the departure avoidance operation by the departure avoidance operation detecting means for detecting that the driver is performing the operation for avoiding the departure when the angle is within the angular range of Since the control amount by the avoidance control means is corrected by the departure avoidance control amount correction means so as to be smaller than when the driver is not detected to be performing the departure avoidance operation, the departure avoidance control means Even when a driver's departure avoidance operation is performed during departure avoidance control, it is possible to avoid excessive vehicle posture change and to ensure appropriate control by the departure avoidance control means while avoiding moderate departure Departure avoidance control can be performed, and it is possible to avoid giving the driver a feeling of excessive control.

Embodiments of the present invention will be described below.
FIG. 1 is a schematic vehicle configuration diagram illustrating an example of a lane departure prevention apparatus according to the first embodiment. This vehicle is a rear-wheel drive vehicle equipped with an automatic transmission and a conventional differential gear, and the braking device can control the braking force of the left and right wheels independently of the front and rear wheels.
Reference numeral 1 in FIG. 1 is a brake pedal, 2 is a booster, 3 is a master cylinder, and 4 is a reservoir. Normally, the braking fluid is boosted by the master cylinder 3 in accordance with the amount of depression of the brake pedal 1 by the driver. The pressure is supplied to the wheel cylinders 6FL to 6RR of the wheels 5FL to 5RR. A brake fluid pressure control circuit 7 is interposed between the master cylinder 3 and the wheel cylinders 6FL to 6RR. It is also possible to individually control the brake fluid pressures of the wheel cylinders 6FL to 6RR in the brake fluid pressure control circuit 7.

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

Further, in this vehicle, driving torque to the rear wheels 5RL and 5RR which are driving wheels is controlled by controlling the operating state of the engine 9, the selected transmission ratio of the automatic transmission 10, and the throttle opening of the throttle valve 11. A drive torque control unit 12 is provided for control. The operating state control of the engine 9 can be controlled, for example, by controlling the fuel injection amount and the ignition timing, and can also be controlled by controlling the throttle opening at the same time.
The drive torque control unit 12 can independently control the drive torque of the rear wheels 5RL and 5RR that are drive wheels. However, a drive torque command value is input from the control unit 8 described above. Sometimes, the drive wheel torque is controlled while referring to the drive torque command value.

In addition, the vehicle includes a monocular camera 13 and a camera controller that are configured by a CCD camera or the like as a front external field recognition sensor for detecting the position of the host vehicle in the travel lane for determining departure from the travel lane of the host vehicle. 14 is provided. The camera controller 14 detects, for example, a lane marker such as a white line from a captured image in front of the host vehicle captured by the monocular camera 13 to detect a travel lane, and the yaw angle of the host vehicle with respect to the travel lane according to a known procedure. φ, that is, the direction of the host vehicle with respect to the travel lane, the lateral displacement X of the host vehicle from the center of the travel lane, the curvature ρ of the travel lane, the travel lane width W, and the like can be calculated.
The camera controller 14 detects a driving lane by a known procedure, for example, as described in JP-A-11-296660, and detects each lane marker. Calculate the data.

  The vehicle also includes an acceleration sensor 15 that detects longitudinal acceleration Xg and lateral acceleration Yg generated in the host vehicle, a yaw rate sensor 16 that detects yaw rate γ generated in the host vehicle, an output pressure of the master cylinder 3, so-called master. A master cylinder pressure sensor 17 that detects the cylinder pressure Pm, an accelerator pedal depression amount, that is, an accelerator opening sensor 18 that detects the accelerator opening Acc, a steering angle sensor 19 that detects the steering angle θ of the steering wheel 21, and each wheel 5FL Are provided with wheel speed sensors 22FL to 22RR for detecting a rotational speed of 5RR, so-called wheel speed Vwi (i = FL to RR), and a direction indicating switch 20 for detecting a direction indicating operation by a direction indicator. Output to the control unit 8.

  Further, the yaw angle φ of the host vehicle with respect to the travel lane detected by the camera controller 14, the lateral displacement X of the host vehicle from the center of the travel lane, the curvature ρ of the travel lane, the travel lane width W, and the drive torque control unit 12 are controlled. The drive torque Tw on the wheel axis, the required drive force τm corresponding to the driver's accelerator operation amount, the engine torque τa, etc. are also output to the control unit 8.

  If the detected vehicle traveling state data has left and right directionality, the left direction is the positive direction and the right direction is the negative direction. That is, the yaw rate γ, the lateral acceleration Yg, the steering angle θ, and the yaw angle φ are positive values when turning left and negative values when turning right. Further, the lateral displacement X becomes a positive value when shifted to the left from the center of the traveling lane, and becomes a negative value when shifted laterally. Further, the curvature ρ of the traveling lane becomes a positive value in the case of the left curve, and becomes a negative value in the case of the right curve.

  Next, the processing procedure of the arithmetic processing performed by the control unit 8 will be described with reference to the flowchart of FIG. This calculation process is executed by a timer interrupt every predetermined sampling time ΔT (for example, 10 [ms]). In this flowchart, no communication step is provided, but information obtained by the arithmetic processing is updated and stored in the storage device as needed, and necessary information is read out from the storage device as needed.

  In this calculation process, first, the longitudinal acceleration Xg, lateral acceleration Yg, yaw rate γ, wheel speed Vwi, accelerator opening Acc, master cylinder pressure Pm, steering angle θ, Direction indication switch signal, yaw angle φ of own vehicle with respect to traveling lane from camera controller 14, lateral displacement X of own vehicle from center of traveling lane, curvature ρ of traveling lane, traveling lane width W, driving torque control unit 12 Then, information such as the driving torque Tw on the wheel axle, the required driving force τm corresponding to the driver's accelerator operation amount, and the engine torque τa is read.

In addition, the traveling speed V of the host vehicle is calculated from the average value of the front left and right wheel speeds VwFL and VwFR, which are non-driven wheels, among the wheel speeds Vwi (i = FL to RR).
Here, the case where the traveling speed V is calculated based on the front left and right wheel speeds VwFL, VwFR has been described. For example, the vehicle is equipped with ABS control means for performing known anti-skid control, When the anti-skid control is performed by the ABS control means, the estimated vehicle speed estimated in the process of the anti-skid control may be used.

Next, the process proceeds to step S2, and a future estimated lateral displacement Xs is calculated from the following equation (1) as an estimated deviation value.
Xs = Tt × V × (φ + Tt × V × ρ) + X (1)
In the equation (1), Tt is the vehicle head time, V is the traveling speed of the host vehicle calculated in step S1, φ is the yaw angle of the vehicle with respect to the traveling lane of the host vehicle, ρ is the curvature of the traveling lane, and X is the current time Is the lateral displacement from the center of the travel lane.

  Here, the case where the estimated lateral displacement Xs is calculated based on the equation (1) has been described. However, the present invention is not limited to this. For example, the estimated lateral displacement Xs is calculated in consideration of the yaw rate acting on the vehicle. May be. For example, when the accuracy of the yaw rate sensor 16 is high and noise is low, the deviation alarm and the deviation prevention control are activated at a more appropriate timing by calculating the estimated lateral displacement Xs in consideration of the yaw rate. It can also be released.

  Note that Tt is the vehicle head time for calculating the forward gaze distance, and when the vehicle head time Tt is multiplied by the traveling speed V of the host vehicle, the front gaze distance is obtained. That is, the estimated lateral displacement from the center of the traveling lane after the vehicle head time Tt becomes the estimated lateral displacement Xs in the future. As will be described later, in the present embodiment, when the estimated lateral displacement Xs in the future is equal to or greater than a predetermined deviation determination value, it is determined that the host vehicle may deviate from the traveling lane or tend to deviate.

  In general, it often takes some time for the driver to notice the warning and perform the departure avoidance operation. Even if it is determined that there is a high possibility that the host vehicle will depart from the lane and the departure prevention control is activated, the own vehicle does not immediately move toward the center of the lane in which the vehicle is traveling along with the operation of the departure prevention control. However, although the speed of deviating from the lane becomes low, the vehicle moves toward the outside of the traveling lane until the vehicle turns to the inside of the lane. For this reason, it is desirable to set the vehicle head time Tt to a value larger than “0” [s] in order to prompt the driver to perform the lane departure prevention operation with a margin.

Next, the process proceeds to step S3, where a departure judgment is made as to whether or not the host vehicle tends to depart from the traveling lane.
This departure determination is performed by comparing the estimated lateral displacement Xs calculated in step S2 with the departure determination threshold value Xc. Specifically, when Xs ≧ Xc, it is determined that the vehicle will deviate to the left, and the departure determination flag FLD is set to “LEFT”. Further, when Xs ≦ −Xc, it is determined that the vehicle departs to the right, and the departure determination flag FLD is set to “RIGHT”. If Xs ≧ Xc and Xs ≦ −Xc are not satisfied, it is determined that the host vehicle is not in a departure state, and the departure determination flag FLD is set to “OFF”.

The departure determination threshold value Xc is a constant, and in Japan, the lane width of an expressway is about 3.5 [m], so it may be set to about 0.8 [m], for example. Further, for example, a value obtained by subtracting a half value of the vehicle width of the host vehicle from a half value of the traveling lane width W and, for example, 0.8 [m], whichever is smaller, may be used.
Here, the case where the departure determination flag FLD is set by comparing the estimated lateral displacement Xs with the departure determination threshold value Xc has been described. However, is the driver more willing to change lanes? The departure determination flag FLD may be set in consideration of whether or not.

  For example, it is determined whether or not the direction indicating switch 20 is in the on state. If the direction indicating switch 20 is in the on state, the indicating direction of the direction indicating switch 20 and the departure direction specified by the estimated lateral displacement Xs calculated in step S2. Determine whether or not. Then, when they match, it is determined that the lane change is to be performed, and when the departure determination flag FLD set according to the comparison result between the estimated lateral displacement Xs and the departure determination threshold value Xc is “ON”. This is changed to “OFF”. On the other hand, if the indicated direction of the direction indicating switch 20 and the departure direction specified by the estimated lateral displacement Xs do not match, it is determined that the lane change has not occurred, and the estimated lateral displacement Xs is compared with the departure determination threshold value Xc. The set value of the deviation determination flag FLD set according to the result is maintained as it is.

  When the direction indicating switch 20 is switched from the on state to the off state, it is determined that the lane change is in a transitional state until the predetermined time elapses thereafter, and the direction indicating switch 20 is in the off state. Even so, the processing is performed assuming that it is in the ON state. Then, when a predetermined time elapses from the time when the direction indicating switch 20 is switched from the on state to the off state, the lane change is finished, and thereafter, processing is performed according to the state of the direction indicating switch 20.

Note that the predetermined time may be considered that the traveling position of the host vehicle has reached a position from the center of the lane of the lane change destination from the time when the direction indicating switch 20 is switched to the OFF state at the later stage of the lane change. The possible time is set, for example, about 4 seconds.
Next, the process proceeds to step S4, and a target yaw moment Msb, which is a yaw moment necessary for avoiding deviation, is calculated.

Specifically, when the departure determination flag FLD is “LEFT”, the target yaw moment Msb is calculated according to the following equation (2). When the departure determination flag FLD is “RIGHT”, the target yaw moment Msb is calculated according to the following equation (3). When the departure determination flag FLD is “OFF”, it is determined that the host vehicle is not in a departure state, and it is not necessary to generate the yaw moment, so the target yaw moment is set to Msb = 0.
Msb = −K1 × K2 × (Xs−Xc) (2)
Msb = −K1 × K2 × (Xs + Xc) (3)

  In the equations (2) and (3), K1 is a constant determined by vehicle specifications. K2 is a proportional coefficient set in accordance with the traveling speed V of the host vehicle. For example, when the traveling speed V is relatively high, the proportional coefficient K2 is set to a relatively small value to set the target yaw moment Msb. To prevent the vehicle behavior from becoming unstable due to a large yaw moment acting during high-speed driving, and conversely, when the driving speed V is relatively low, it is set to a proportionally large value to obtain a sufficient target yaw. By securing the moment Msb and generating the yaw moment, it is possible to promptly recover from the departure state.

Next, the process proceeds to step S5, and it is determined whether or not a departure avoidance operation has been performed.
Specifically, the steering angle θs when the departure determination result FLD changes from “OFF” to “LEFT”, or changes from “OFF” to “RIGHT”, that is, when departure avoidance control is started. On the other hand, the determination is made based on whether or not the steering angle θ is switched back in the departure avoidance direction. The steering angle (hereinafter also referred to as the control start steering angle) θs when the above-described departure avoidance control is started is determined when the departure determination result FLD changes from “OFF” to “LEFT” or “OFF”. The deviation avoidance control is started when it is changed from “RIGHT” to “RIGHT” and stored in a predetermined storage area.

The departure determination flag FLD is “LEFT”, it is determined that the departure is leftward, and the steering angle θ at the present time is smaller than the steering angle θs at the start of control (θ <θs), which is greater than at the start of the control. When it is determined that the switch has been made to return to the right, it is determined that the driver has performed a departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.
Further, the departure determination flag FLD is “RIGHT”, it is determined that the departure is in the right direction, and the steering angle θ at the current time is larger than the steering angle θs at the start of control (θ> θs), which is higher than at the start of the control. When it is determined that the vehicle has been switched back to the left, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

In other cases, it is determined that the departure avoidance operation is not performed, and the departure avoidance operation flag FDR is set to “OFF”.
Next, the process proceeds to step S6, and a decrease speed dMs of the target yaw moment Msb is calculated according to the determination result of the presence or absence of the driver's departure avoidance operation in step S5. As will be described later, the decreasing speed dMs is for defining the changing speed when the target yaw moment Msb is corrected in the suppression direction.

First, when the departure avoidance operation flag FDR is “OFF”, the decrease rate is dMs = 0.
On the other hand, when the departure avoidance operation flag FDR is “ON”, for example, as shown in FIG. 3A, in the departure avoidance direction with respect to the steering angle (control start steering angle) θs at the start of departure avoidance control. The reduction speed dMs is calculated according to the steering angle switchback amount | θ−θs | (absolute value).

  In FIG. 3A, the horizontal axis represents the steering angle switchback amount | θ−θs | in the departure avoidance direction, and the vertical axis represents the decrease speed dMs of the target yaw moment Msb. This decrease speed dMs is set to dMs = 0 when the steering angle switchback amount | θ−θs | is zero, and when the steering angle switchback amount | θ−θs | increases, the decrease speed dMs also increases proportionally. When the steering angle switchback amount | θ−θs | becomes a value in a relatively large region, the decrease speed dMs is maintained at a constant value. That is, the larger the steering angle switchback amount is, and the larger the vehicle attitude change in the departure avoidance direction is expected by the steering operation, the larger the reduction speed dMs is set, and the target yaw moment Msb is greatly reduced. ing.

  Here, the case where the decrease rate dMs is set with the characteristics shown in FIG. 3A has been described, but the present invention is not limited to this. For example, in order to avoid the target yaw moment Msb from being reduced despite the minute detection accuracy variation of the steering angle, etc., even though the driver is not performing the departure avoidance operation, for example, FIG. ), A dead zone may be provided in a range where the steering angle return amount is relatively small, and as shown in FIG. 3C, in a range where the steering angle return amount is relatively small, In order to avoid that the target yaw moment Msb is largely suppressed, the amount of change in the reduction speed dMs with respect to the change in the steering angle return amount may be made smaller.

  When the target yaw moment decrease rate dMs is calculated in this way, the process proceeds to step S7, where the target yaw moment Msb calculated in step S4 is decreased at the decrease rate dMs calculated in step S6, The target yaw moment correction value Ms is used. (Ms = Msb−dMs). When Ms <0, the target yaw moment correction value is Ms = 0.

Next, the process proceeds to step S8, where the target braking hydraulic pressure Psi (i = FL to RR) of each wheel is calculated as the target braking force for avoiding the departure.
First, when the departure determination flag FLD is “OFF”, the host vehicle is not in a departure state and there is no need to generate a yaw moment. The wheel target braking fluid pressure Psi (i = FL to RR) is calculated from the following equation (4). Note that PmR in the equation (4) is the rear wheel master cylinder hydraulic pressure in consideration of the front-rear distribution calculated from the master cinder hydraulic pressure Pm.
PsFL = PsFR = Pm
PsRL = PsRR = PmR (4)

On the other hand, when the departure determination flag FLD is “ON”, the target braking hydraulic pressure Psi (i = FL to RR) is calculated in consideration of the target yaw moment correction value Ms calculated in step S7.
First, cases are classified according to the magnitude of the target yaw moment correction value Ms, and the braking force differences ΔPsF and ΔPsR between the left and right wheels of the front and rear wheels are calculated. When the absolute value | Ms | of the target yaw moment correction value is smaller than a preset threshold value Ms0 (| Ms | <Ms0), the braking force differences ΔPsF and ΔPsR between the front and rear wheels are obtained from the following equation (5). When the calculated absolute value | Ms | of the target yaw moment correction value is equal to or greater than a preset threshold value Ms0 (| Ms | ≧ Ms0), the braking force differences ΔPsF and ΔPsR between the front and rear wheels are expressed by the following formulas ( Calculate from 6).

When | Ms | <Ms0, ΔPsF = 0
ΔPsR = 2 × KbR × | Ms | / T (5)
When | Ms | ≧ Ms0, ΔPsF = 2 × KbF × (| Ms | −Ms0) / T
ΔPsR = 2 × KbR × Ms0 / T (6)
In addition, T in Formula (5) and (6) is a tread. KbF and KbR are conversion coefficients for converting braking force into braking hydraulic pressure, and are constants determined by brake specifications.

Then, the target braking hydraulic pressure Psi (i = FL to RR) of each wheel is calculated in consideration of the departure direction and the master cylinder hydraulic pressure Pm that is a braking operation by the driver. Specifically, when the target yaw moment correction value Ms is a negative value, that is, when the host vehicle is about to deviate in the left direction, the target braking fluid pressure Psi is calculated by the following equation (7).
PsFL = Pm
PsFR = Pm + ΔPsF
PsRL = PmR
PsRR = PmR + ΔPsR (7)

On the other hand, when the target yaw moment correction value Ms is equal to or greater than zero, that is, when the host vehicle is about to depart from the lane in the right direction, the target braking fluid pressure Psi is calculated by the following equation (8).
PsFL = Pm + ΔPsF
PsFR = Pm
PsRL = PmR + ΔPsR
PsRR = PmR (8)
When the target brake fluid pressure Psi is calculated in this way, the process proceeds to step S9, and the target brake fluid pressure Psi calculated in step S8 is output to the brake fluid pressure control circuit 7.

When the control unit 8 detects a lane departure, an alarm device is provided to warn the driver. When the departure determination flag FLD is “ON”, a yaw moment is generated and this alarm is generated. The device may be activated. This alarm device includes, for example, a speaker and a monitor for generating sound and buzzer sound, and issues a warning to the driver by display information and sound information.
The calculation process shown in FIG. 2 is completed by the above process. When a series of arithmetic processing is completed, the timer interrupt processing is terminated and the process returns to a predetermined main program.

Next, the operation of the first embodiment will be described.
When the host vehicle is traveling straight ahead from the center of the travel lane, the estimated lateral displacement Xs is relatively small. Therefore, the estimated lateral displacement Xs is smaller than the departure determination threshold value Xc or less than -Xc. Since it becomes larger, the departure determination flag FLD is set to “OFF”. Therefore, the target yaw moment is set to Msb = 0 (steps S1 to S4).

Therefore, in the calculation process of FIG. 2, since the fluid pressure corresponding to the master cylinder pressure Pm is set as the target brake fluid pressure Psi in the process of step S8, no yaw moment is generated, and the driver's operation The vehicle behavior is in line with the operation.
If the host vehicle tends to deviate to the left from this state, the deviation determination flag FLD is set to “OFF” while the estimated lateral displacement Xs is smaller than the deviation determination threshold value Xc. Do not do.

  From this state, when the lane departure of the host vehicle further proceeds and the estimated lateral displacement Xs becomes equal to or greater than the departure determination threshold value Xc, the departure determination flag FLD is set to “LEFT”, and the estimated lateral displacement Xs and departure determination are made in step S4. A target yaw moment Msb corresponding to a difference from the threshold value Xc, that is, a lateral deviation amount of the host vehicle is calculated. At this time, if the driver is not performing the steering operation in the departure avoidance direction, the departure avoidance operation flag FDR is set to “OFF” in the process of step S5 (step S5), so that the target yaw moment Is decreased to dMs = 0 (step S6).

  For this reason, the target yaw moment Msb is not corrected, and the target yaw moment Msb is set as the target yaw moment correction value Ms as it is, so that a yaw moment corresponding to the lateral deviation amount of the host vehicle is generated in the vehicle. Thus, sufficient yaw moment for avoiding lane departure is generated in the vehicle, and sufficient departure avoidance is achieved by departure avoidance control. Further, since the departure determination flag FLD is switched to “LEFT”, the steering angle θ at this time is stored in the predetermined storage area as the steering angle θs at the start of the departure avoidance control operation.

From this state, if the driver recognizes that the host vehicle tends to deviate from the lane due to the yaw moment acting on the host vehicle, etc. When the angle θ becomes smaller than the steering angle θs at the start of the departure avoidance control operation stored in the predetermined storage area (θ <θs), it is determined that the driver has performed the departure avoidance operation. The avoidance operation flag FDR is set to “ON” (step S5).
Therefore, the target yaw moment decrease speed dMs is calculated from the control map shown in FIG. 3A according to the steering angle switchback amount | θ−θs |, and the decrease speed dMs is subtracted from the target yaw moment Msb. A target yaw moment correction value Ms is calculated, and braking force control is performed to generate the target yaw moment correction value Ms.

For example, when the driver steers in the departure avoidance direction and the steering angle θ is switched back beyond the steering angle θs at the start of control, and this state is maintained, the decrease speed dMs increases as the steering angle switch back amount increases. and its later when maintaining steering angle, will be maintained reducing speed dMs corresponding to the amount of switching back to the control start time of steering angle [theta] s. Therefore, when the control yaw moment Msb exceeds the steering angle θs at the start of control, the target yaw moment Msb is reduced according to the return amount, and is further decreased as the return amount is larger. When the steering angle is maintained, the speed is subsequently reduced at the reduction speed dMs at this time .

  At this time, the target yaw moment Msb itself calculated from the host vehicle moving in the departure avoidance direction by steering in the departure avoidance direction gradually decreases. Therefore, when the steering in the departure avoidance direction is performed and the steering angle θ falls below the steering angle θs at the start of control, the target yaw moment correction value Ms decreases according to the return amount by steering, and the return amount becomes smaller. If it increases, the degree of decrease also increases accordingly. Further, as the vehicle posture changes in the departure avoidance direction by steering, the degree of decrease increases accordingly. When the host vehicle returns to a certain extent in the departure avoidance direction and the target yaw moment Msb becomes equal to or less than the decrease speed dMs, the target yaw moment correction value becomes Ms = 0, and no yaw moment is generated thereafter.

Then, when the yaw moment is generated in this way and the estimated lateral displacement Xs of the host vehicle is decreased by the steering operation by the driver and falls below the departure determination threshold value Xc, the departure determination flag FLD is set at this time. Set to “OFF”, the control intervention by the departure avoidance control ends.
Here, the target yaw moment correction value Ms is suppressed to a value smaller than the target yaw moment Msb calculated as the yaw moment necessary for suppressing the lateral deviation amount. Since the driver is steering in the departure avoidance direction as much as the moment is reduced, the vehicle posture change due to the departure avoidance control and the vehicle posture change due to the driver's steering avoidance operation result in A vehicle posture change that can avoid a lane departure occurs.

  At this time, when the driver is steering in the departure avoidance direction and the yaw moment corresponding to the lateral deviation amount is generated, the vehicle posture changes due to the steering operation in the departure avoidance direction by the driver. Nevertheless, the vehicle posture change sufficient to suppress the lateral deviation amount is generated by the departure avoidance control, and in some cases, the posture change in the lane departure avoidance direction may become too large.

However, as described above, when the steering avoidance operation is performed by the driver, the yaw moment generated by the departure avoidance control is suppressed according to the steering angle switchback amount | θ−θs |. It is possible to avoid an excessive change in posture in the direction, and to avoid an unnecessary change in the vehicle posture caused by the departure avoidance control. Therefore, it is possible to avoid an excessive tendency of departure avoidance control, and to prevent the driver from feeling uncomfortable.
At this time, since the target yaw moment Msb is suppressed according to the steering angle switchback amount | θ−θs |, the vehicle posture by the deviation prevention control according to the vehicle posture change amount by the driver's steering operation. The change can be suppressed, and the target yaw moment Ms can be accurately limited.

  Further, since the target yaw moment correction value Ms is calculated by decreasing the decrease speed dMs corresponding to the steering angle return amount from the target yaw moment Msb, the target yaw moment Msb is decreased as described above. When dMs is reached, the generation of the yaw moment ends. At this time, the decrease speed dMs is a value set in accordance with the expected posture change in accordance with the return amount, so that even if the generation of the yaw moment is terminated at this time, the necessary vehicle posture change is realized. The generation of the yaw moment can be terminated before the actual vehicle attitude change occurs. Therefore, before the estimated lateral displacement Xs becomes equal to or less than the departure determination threshold value Xc, it is possible to end the generation of the yaw moment at an earlier time by predicting the change in the attitude of the vehicle, and to end the return from the lane departure tendency. The excessive control feeling given to the driver at the time can be more accurately suppressed.

  At this time, based on the steering angle θs at the start of the departure prevention control operation, it is determined that the departure avoidance operation is performed when the steering angle θ is operated in the departure avoidance direction with respect to the steering angle θs. Even if steering is performed in the avoidance direction, the target yaw moment Msb is not suppressed when the steering angle is in the departure direction rather than the steering angle θs and a sufficient yaw moment for avoiding lane departure is required. Therefore, by generating sufficient yaw moment by the departure prevention control together with the driver's steering avoidance operation, the lane departure can be quickly suppressed.

  Here, in the first embodiment, the arithmetic processing in FIG. 2 corresponds to the departure avoidance control means, the processing in step S5 corresponds to the departure avoidance operation detecting means, and the processing in steps S6 and S7 is the departure avoidance. Corresponding to the control amount correcting means, the steering angle sensor 19 corresponds to the steering angle detecting means. Further, when the deviation determination result FLD is changed from “OFF” to “LEFT” or changed from “OFF” to “RIGHT” in the process of step S3, the steering angle θ at this time is controlled by the deviation avoidance control. Whether the process of storing the steering angle θs at the start of the operation in the predetermined storage area corresponds to the steering angle holding means, and whether the departure avoidance operation was performed using the steering angle θs at the start of the departure avoidance control operation in the process of step S5 The process for determining whether or not corresponds to the first avoidance operation determination means. Further, the process of step S6 corresponds to the decrease speed setting means, and the processes of step S4, step S8, and step S9 correspond to the yaw moment generating means.

Next, a second embodiment of the present invention will be described.
The second embodiment is different from the first embodiment except that the determination method when determining whether the driver has performed the steering avoidance operation and the calculation method of the target yaw moment correction value Ms are different. The same.
FIG. 4 is a flowchart illustrating an example of a processing procedure of arithmetic processing according to the second embodiment, which is executed by the control unit 8.

The processing from step S11 to step S14 is the same as the processing from step S1 to step S4 in FIG. 2 in the first embodiment. When the control unit 8 starts the arithmetic processing, it reads various data and travels. A speed V is calculated (step S11), and a future estimated lateral displacement Xs is calculated (step S12).
Then, the estimated lateral displacement Xs is compared with the departure judgment threshold value Xc, and when the estimated lateral displacement Xs becomes greater than or equal to the departure judgment threshold value Xc, or the estimated lateral displacement Xs is less than or equal to the departure judgment threshold value -Xc. At this time, it is determined that the host vehicle tends to deviate, and the deviating determination flag FLD is set to “LEFT” or “RIGHT” according to the deviating direction (step S13). When the departure determination flag FLD is not “OFF”, a target yaw moment Msb that can prevent departure from the lane is calculated according to the amount of lateral deviation that is the difference between the estimated lateral displacement Xs and the departure determination threshold value Xc. (Step S14).

Next, the process proceeds to step S15, and a driver's departure avoidance operation determination is performed. In the second embodiment, the departure avoidance operation is determined according to the following procedure.
Specifically, the steering angle θs when the departure determination result FLD changes from “OFF” to “LEFT”, or changes from “OFF” to “RIGHT”, that is, when departure avoidance control is started. On the other hand, the determination is made based on whether or not the steering angle θ is turned back by the threshold θc or more in the departure avoidance direction. The steering angle θs when the departure avoidance control is started is avoided when the departure determination result FLD changes from “OFF” to “LEFT” or from “OFF” to “RIGHT”. The control is started and stored in a predetermined storage area.

  The departure determination flag FLD is “LEFT”, and it is determined that the departure is leftward, and the steering angle θ at the present time is switched back from the steering angle θs at the start of control by a predetermined value θc in the departure avoidance direction. When it is determined that the angle is smaller than the angle (θ <θs−θc), and when it is determined that the vehicle has been turned back more than the predetermined value θc to the right from the start of control, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR Is set to “ON”.

  Further, the departure determination flag FLD is “RIGHT”, it is determined that the departure is in the right direction, and the steering angle θ at the current time is switched back from the steering angle θs at the start of control by the predetermined value θc in the departure avoidance direction. Is greater than (θ> θs + θc), and when it is determined that the predetermined value θc or more has been turned back to the left from the start of control, it is determined that the driver has performed a departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”. And

In other cases, it is determined that the departure avoidance operation is not performed, and the departure avoidance operation flag FDR is set to “OFF”.
Subsequently, the process proceeds to step S16, where the target yaw moment Msb calculated at step S14 is decreased at a preset reduction speed dMs1, and the target yaw moment correction value Ms (Ms = Msb−dMs1) is reduced. ).

Next, the process proceeds to step S17, and thereafter, the target braking hydraulic pressure Psi (i = FL to RR) of each wheel for avoiding the deviation is calculated in the same manner as in the first embodiment, and the calculated target is calculated. The brake fluid pressure Psi is output to the brake fluid pressure control circuit 7 (step S18).
In other words, in this second embodiment, when the steering angle θ is switched back in the departure avoidance direction by a predetermined value θc or more than the steering angle θs at the start of departure avoidance control, the driver performs the departure avoidance operation. And starting to suppress the target yaw moment Msb, it is possible to prevent the target yaw moment Msb from being suppressed in a state where the steering operation by the driver is insufficient, and to change the vehicle posture by the departure prevention control. And excessive control due to a change in the vehicle posture caused by the departure avoidance operation by the driver is avoided.

Therefore, in this case as well, the same effect as the first embodiment can be obtained, and in this case, the reduction rate of the target yaw moment is set to the fixed value dMs1, so that it is as in the first embodiment. In comparison with the case of calculating the decrease rate dMs, the processing load of the control unit 8 can be reduced accordingly.
In the second embodiment, as in the first embodiment, the decrease rate dMs can be changed according to the switchback amount. In this case, the deviation depends on a deviation between the steering angle θ and the steering avoidance angle θs at the start of control by a predetermined value θc or a deviation between the steering angle θ and the steering angle θs at the start of control. The decrease rate dMs may be changed so as to increase as the value increases.

  Further, in the first and second embodiments, for example, a duration measuring means for measuring the elapsed time from the time when the departure avoidance operation flag FDR is “ON” is provided, and the time decreases as the measurement time becomes longer. The decreasing speed dMs may be set so that the speed dMs becomes a larger value. That is, as the duration time during which the departure avoidance operation is performed is longer, a larger vehicle posture change due to the steering operation can be expected. Therefore, the target yaw moment is increased so that the decrease speed dMs increases as the duration time increases. By correcting Msb, the same effect as described above can be obtained.

  Here, in the second embodiment, the calculation process of FIG. 4 corresponds to the departure avoidance control means, the process of step S15 corresponds to the departure avoidance operation detection means, and the process of step S16 corresponds to the departure avoidance control amount correction. Corresponding to the means, the steering angle sensor 19 corresponds to the steering angle detecting means. Further, when the deviation determination result FLD is changed from “OFF” to “LEFT” or changed from “OFF” to “RIGHT” in the process of step S13, the steering angle θ at this time is determined as a deviation avoidance. The process of storing the steering angle θs at the start of the control operation in the predetermined storage area corresponds to the steering angle holding means, and the departure avoidance operation is performed using the steering angle θs at the start of the departure avoidance control operation in the process of step S15. The process for determining whether or not it has been received corresponds to the first avoidance operation determination means. Further, the processing of step S14, step S17 and step S18 corresponds to the yaw moment generating means.

Next, a third embodiment of the present invention will be described.
The third aspect of the invention is the same as that of the first embodiment except that the calculation method of the target yaw moment correction value Ms is different from that of the first embodiment. The detailed description is omitted.
FIG. 5 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by the control unit 8 in the third embodiment.

  The processing from step S21 to step S25 is the same as the processing from step S1 to step S5 in FIG. 2 in the first embodiment, and reads various data and calculates the traveling speed V (step S21). After calculating the estimated lateral displacement Xs in the future (step S22), the estimated lateral displacement Xs is compared with the departure determination threshold value Xc to determine the departure of the host vehicle (step S23). Then, the target yaw moment Msb is calculated according to the departure determination result (step S24), and the departure prevention control which is the steering angle θ at the time when the departure determination flag FLD is switched from “OFF” to “LEFT” or “RIGHT”. It is determined whether or not the steering angle θ is switched back in the departure avoidance direction rather than the steering angle θs at the start of operation (step S25).

Next, the process proceeds to step S26, and the target yaw moment correction gain KDR is calculated according to the determination result of the presence or absence of the driver's departure avoidance operation in step S25. Specifically, when the departure avoidance operation flag FDR is “OFF”, that is, when the driver is not performing the departure avoidance operation, the correction gain KDR is initialized. For example, it is set to 100 [%].
On the other hand, when the departure avoidance operation flag FDR is “ON”, that is, when the driver is performing the departure avoidance operation, for example, as shown in FIG. 6A, the steering angle θs at the start of departure avoidance control. The correction gain KDR is calculated according to the steering angle switchback amount | θ−θs | (absolute value) in the deviation avoidance direction with respect to.

  In FIG. 6A, the horizontal axis represents the steering angle return amount | θ−θs | in the departure avoidance direction, and the vertical axis represents the target yaw moment correction gain KDR. The correction gain KDR is set to 100 [%] when the steering angle return amount | θ−θs | is zero, and the correction gain KDR is also inversely proportional to the increase of the steering angle return amount | θ−θs |. In a region where the steering angle switchback amount | θ−θs | is relatively large, the correction gain KDR is maintained at a constant value. In other words, the correction gain KDR is set to a smaller value as the amount of return is larger and a larger vehicle attitude change is expected by the steering operation, and the target yaw moment Msb is suppressed according to the correction gain KDR, as will be described later. Thus, the target yaw moment Msb is suppressed to a smaller value as the vehicle posture change is expected by the steering operation.

  Although the case where the correction gain KDR is set with the characteristics shown in FIG. 6A has been described here, the present invention is not limited to this. For example, in order to avoid that the target yaw moment Msb is largely suppressed despite the minute detection accuracy variation of the steering angle, etc., even though the driver does not perform the departure avoidance operation, FIG. As shown in FIG. 5, a dead zone may be provided in a range where the steering angle switching back amount is relatively small. Further, as shown in FIG. 6C, the change amount of the correction gain KDR with respect to the change in the return amount may be set to be smaller in the range where the steering angle return amount is relatively small.

Next, the process proceeds to step S27, and the target yaw moment correction value Ms (= KDR × Msb) is obtained by multiplying the target yaw moment Msb calculated in step S24 by the correction gain KDR of the target yaw moment calculated in step S26. ) Is calculated.
Next, the process proceeds to step S28, and thereafter, the target braking fluid pressure Psi is calculated in the same manner as in the first embodiment, and is output to the braking fluid pressure control circuit 7 (step S29).

As described above, in the third embodiment, the correction gain KDR is calculated according to the steering angle return amount | θ−θs | in the departure avoidance direction, and the target yaw moment Msb is multiplied by the correction gain KDR. Thus, the target yaw moment Msb is corrected according to the steering angle switchback amount | θ−θs |.
Therefore, for example, in a state where the host vehicle is in a lane departure tendency and the yaw moment is acting on the host vehicle due to the intervention of the departure avoidance control, the driver recognizes the lane departure tendency and performs a steering operation in the departure avoidance direction. Then, the correction gain KDR corresponding to the steering angle switchback amount at the time when it is determined that the steering operation is performed is set, and the target yaw moment Msb corresponding to the lateral deviation amount of the host vehicle is suppressed according to the switchback amount. Will be.

  Since the vehicle posture change due to the steering operation is predicted to be larger as the return amount is larger, the target yaw moment Msb is suppressed to be smaller. Conversely, the vehicle posture change due to the steering operation is expected to be smaller as the return amount is smaller. Therefore, the degree of suppression of the target yaw moment Msb is small. Then, when the direction of the host vehicle is changed to the departure avoidance direction by the steering operation and the target yaw moment Msb is reduced accordingly, the target yaw moment Msb is reduced while being suppressed at a degree of suppression according to the switchback amount. When the estimated lateral displacement Xs becomes equal to or less than the departure judgment threshold value Xc, the departure from the departure avoidance control is terminated because it is recovered from the departure tendency.

  Therefore, also in this case, when the steering operation is performed while the departure avoidance control is intervening, the control amount by the departure avoidance control is suppressed, so even when the driver performs the steering operation, It does not give the driver a sense of over-control. Also in this case, the steering yaw return amount | θ−θs | is large, and the target yaw moment Msb is suppressed more greatly as the vehicle posture change due to the steering operation can be expected. Can be avoided accurately.

  In the third embodiment, when the steering angle θ changes in the departure avoidance direction with respect to the steering angle θs at the start of the departure avoidance control operation, it is determined that the driver has performed the departure avoidance operation. However, the present invention is not limited to this, and the steering angle θ has changed in the departure avoidance direction by a predetermined value θc from the steering angle θs at the start of the departure avoidance control operation, as in the second embodiment. It may be determined that the departure avoidance operation is performed when the departure avoidance direction is greater than the angle.

  Here, in the third embodiment, the arithmetic processing in FIG. 5 corresponds to the departure avoidance control means, the processing in step S25 corresponds to the departure avoidance operation detection means, and the processing in steps S26 and S27 is the departure avoidance. Corresponding to the control amount correcting means, the steering angle sensor 19 corresponds to the steering angle detecting means. Further, when the departure determination result FLD is changed from “OFF” to “LEFT” or changed from “OFF” to “RIGHT” in the process of step S23, the steering angle θ at this time is determined as a departure avoidance. The process of storing the steering angle θs at the start of the control operation in the predetermined storage area corresponds to the steering angle holding means, and the departure avoidance operation is performed using the steering angle θs at the start of the departure avoidance control operation in the process of step S25. The process of determining whether or not has corresponded to the first avoidance operation determination means. Further, the process of step S26 corresponds to the gain setting means, and the processes of step S24, step S28 and step S29 correspond to the yaw moment generating means.

Next, the form of Reference Example 1 will be described.
The form of the reference example 1 is the same as that of the first embodiment except that the method for determining the presence / absence of the driver's departure avoidance operation is different, and thus the detailed description of the same part is omitted.
FIG. 7 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by the control unit 8 in the form of the reference example 1 .

  The processing from step S1 to step S4 is the same as the processing from step S1 to step S4 in FIG. 2 in the first embodiment. When the control unit 8 starts the arithmetic processing, it reads various data and travels. The speed V is calculated (step S1), the future estimated lateral displacement Xs is calculated (step S2), the estimated lateral displacement Xs is compared with the departure determination threshold value Xc, and the departure determination is performed and the departure direction is specified. (Step S3), the target yaw moment Msb is calculated according to the deviation determination result (Step S4).

Next, the process proceeds to step S5a, and it is determined whether or not the driver has performed a departure avoidance operation. This determination is made based on the departure direction detected in step S3 and the steering speed dθ in the departure avoidance direction. The steering speed dθ is calculated by differentiating the steering angle θ.
Specifically, first, the departure determination flag FLD is “LEFT”, deviates to the left, and the steering speed dθ in the right direction, which is the departure avoidance direction, is smaller than the departure avoidance operation determination threshold dθc ( dθ <−dθc), that is, when the steering speed dθ in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

  Further, the departure determination flag FLD is “RIGHT”, deviates rightward, and the steering speed dθ in the left direction which is the departure avoidance direction is larger than the departure avoidance operation determination threshold dθc (dθ> dθc). That is, when the steering speed dθ in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

In cases other than the above, it is determined that the departure avoidance operation is not performed, and the departure avoidance operation flag FDR is set to “OFF”. The departure avoidance operation determination threshold value dθc is an absolute value.
Next, the process proceeds to step S6a, and the target yaw moment decrease rate dMs is calculated. The decrease speed dMs is set according to the absolute value | dθ | of the steering speed in the departure avoidance direction, for example, as shown in FIG.

  In FIG. 8, the horizontal axis represents the absolute value | dθ | of the steering speed in the departure avoidance direction, and the vertical axis represents the decrease speed dMs. For example, when the absolute value | dθ | of the steering speed is equal to or less than the departure avoidance operation determination threshold value dθc, the decrease speed dMs is set to zero, and the absolute value | dθ | When it becomes larger than dθc, the decrease speed dMs also increases in proportion to the increase in dθc, and in the region where the absolute value | dθ | of the steering speed is relatively large, the decrease speed dMs is maintained at a constant value. That is, as the steering speed dθ is larger, the change in the steering angle in the departure avoidance direction is larger and the change in the vehicle posture is predicted to increase accordingly, so that the control amount by the departure avoidance control is reduced more quickly. It has become.

Next, the process proceeds to step S8, and thereafter, the target braking fluid pressure Psi of each wheel is calculated and output to the braking fluid pressure control circuit 7 in the same manner as in the first embodiment (step S8). S9).
That is, in the form of the reference example 1 , when the absolute value | dθ | of the steering speed in the departure avoidance direction is larger than the departure avoidance operation determination threshold value dθc, the driver It is determined that the departure avoidance operation has been performed, and the reduction speed dMs of the target yaw moment Msb is set according to the absolute value | dθ | of the steering speed in the departure avoidance direction, and the target yaw moment Msb is suppressed accordingly. At this time, as the absolute value of the steering speed | dθ | is larger and the vehicle posture change expected by the steering operation is predicted to be larger, the decrease speed dMs is increased, and the target yaw moment Msb is decreased more quickly. ing.

  Thus, for example, if the driver recognizes that the driver has a tendency to deviate in the state where departure avoidance control is intervening and switches back to the departure avoidance direction, and maintains the steering angle, the steering operation is performed during steering. As the steering angle increases, that is, the decrease speed dMs of the target yaw moment Msb increases according to the steering speed dθ, the decrease amount of the target yaw moment Msb also increases accordingly. In order to maintain the steering angle, when the steering speed is decreased and the steering angle is maintained, the decrease speed dMs decreases as the steering speed decreases, and the amount of decrease in the target yaw moment Msb also decreases.

For this reason, when the steering angle is changed by the steering operation, the target yaw moment Msb is reduced by an amount corresponding to the change in the vehicle posture by the steering operation when the vehicle posture change is predicted to be large according to the steering speed. When it is predicted that the change in the vehicle posture is reduced in accordance with the decrease in speed, the amount of decrease in the target yaw moment Msb is also reduced.
Therefore, in this case as well, it is possible to obtain the same operational effects as those of the first embodiment, and it is possible to accurately avoid excessive control due to deviation avoidance control according to the steering speed.

Here, in the form of the reference example 1 , the arithmetic processing in FIG. 7 corresponds to the departure avoidance control means, the processing in step S5a corresponds to the departure avoidance operation detection means, and the processing in steps S6a and S7 is the departure avoidance control. Corresponding to the amount correction means, the steering angle sensor 19 corresponds to the steering angle detection means. Further, in the process of step S5a, the process of calculating the steering speed dθ from the steering angle θ corresponds to the steering speed detection means, and it is determined whether the departure avoidance operation has been performed using the steering speed dθ in the process of step S5a. The processing corresponds to second avoidance operation determination means. Further, the process in step S6a corresponds to the decrease speed setting means, and the processes in steps S4, S8, and S9 correspond to the yaw moment generating means.

Next, the form of Reference Example 2 will be described.
The form of the reference example 2 is the same as that of the second embodiment except that the method for determining the presence or absence of the driver's departure avoidance operation is different, and thus the detailed description of the same part is omitted.
FIG. 9 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by the control unit 8 in the form of the reference example 2 .

  The processing from step S11 to step S14 in FIG. 9 is the same as the processing from step S11 to step S14 in FIG. 4 in the second embodiment, and the control unit 8 reads various data when the arithmetic processing is started. At the same time, the travel speed V is calculated (step S11), the future estimated lateral displacement Xs is calculated (step S12), and the estimated lateral displacement Xs is compared with the departure determination threshold value Xc to perform departure determination and departure. The direction is specified (step S13), and the target yaw moment Msb is calculated according to the deviation determination result (step S14).

Next, the process proceeds to step S15a, and it is determined whether or not the driver has performed a departure avoidance operation. This determination, in the form in Reference Example 1, carried out in the process similar to the steps in the step S5a in FIG.
That is, the departure determination flag FLD is “LEFT”, deviates to the left, and the steering speed dθ in the right direction, which is the departure avoidance direction, is smaller than the departure avoidance operation determination threshold dθc (dθ <−dθc). When the steering speed dθ in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

  Further, the departure determination flag FLD is “RIGHT”, deviates rightward, and the steering speed dθ in the left direction which is the departure avoidance direction is larger than the departure avoidance operation determination threshold dθc (dθ> dθc). That is, when the steering speed dθ in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

In cases other than the above, it is determined that the departure avoidance operation is not performed, and the departure avoidance operation flag FDR is set to “OFF”. The departure avoidance operation determination threshold value dθc is an absolute value.
Subsequently, the process proceeds to step S16, and thereafter, similarly to the second embodiment, the target yaw moment Msb is decreased at a preset reduction speed dMs1, and this is reduced to the target yaw moment correction value Ms (Ms = Msb−dMs1). ). And it transfers to step S17, the target braking fluid pressure Psi of each wheel is calculated, and this is output toward the said braking fluid pressure control circuit 7 (step S18).

That is, in the form of this reference example 2 , when the steering speed in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the target yaw moment Msb is set to a decrease speed dMs1 set in advance. Only decrease. Accordingly, in this case as well, when the steering speed in the departure avoidance direction is a certain speed and it is expected that the vehicle posture changes due to the steering operation, the target yaw moment Msb is decreased at the rate of the decrease speed dMs1. Therefore, excessive control by deviation avoidance control can be avoided.

Further, since the speed is decreased at a preset decrease speed dM1, the target yaw moment correction value Ms also changes in the same manner as the change in the target yaw moment Msb. The correction value Ms can be calculated. Further, since the reduction rate of the target yaw moment is set to a fixed value dMs1, the processing load on the control unit 8 can be reduced by that amount compared to the case where the reduction rate dMs is calculated as in the first embodiment. it can.

In the embodiment of the reference example 2, as in the embodiment of the reference example 1 , it is also possible to change the decrease rate dMs. In this case, for example, a duration measuring means for measuring the elapsed time from the time when the departure avoidance operation flag FDR is “ON” is provided, and the decrease speed dMs becomes smaller as the measurement time becomes longer. The decrease rate dMs may be set.

Here, in the embodiment of the reference example 2 , the arithmetic processing of FIG. 9 corresponds to the departure avoidance control means, the processing of step S15a corresponds to the departure avoidance operation detection means, and the processing of step S16 corresponds to the departure avoidance control amount correction means. The steering angle sensor 19 corresponds to the steering angle detection means. Further, in the process of step S15a, the process of calculating the steering speed dθ from the steering angle θ corresponds to the steering speed detection means, and the process of determining whether the steering avoidance operation has been performed based on the steering speed dθ in step S15a. Corresponds to the second avoidance operation determination means. Further, the processing of step S24, step S27 and step S28 corresponds to the yaw moment generating means.

Next, an embodiment of Reference Example 3 will be described.
The form of this reference example 3 is the same as that of the third embodiment except that the method for determining the presence or absence of the driver's departure avoidance operation is different. Detailed description is omitted.
FIG. 10 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by the control unit 8 in the embodiment of the reference example 3 .

  In FIG. 19, the processing from step S21 to step S24 is the same as the processing from step S21 to step S24 of FIG. 5 in the third embodiment, and the control unit 8 reads various data and travel speed. V is calculated (step S21), a future estimated lateral displacement Xs is calculated (step S22), the estimated lateral displacement Xs is compared with the departure determination threshold value Xc, and a departure direction is determined and a departure direction is specified. (Step S23), the target yaw moment Msb is calculated according to the deviation determination result (Step S24).

Next, the process proceeds to step S25a, and it is determined whether or not the driver has performed a departure avoidance operation. This determination is similar to the processing in step S15a of FIG. 9 in the embodiment of the reference example 2 above, based on the departure direction detected in step S23 and the steering speed dθ in the departure avoidance direction. To do. That is, the departure determination flag FLD is “LEFT”, deviates to the left, and the steering speed dθ in the right direction as the departure avoidance direction is smaller than the departure avoidance operation determination threshold dθc (dθ <−dθc). That is, when the steering speed dθ in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

  Further, the departure determination flag FLD is “RIGHT”, deviates rightward, and the steering speed dθ in the left direction which is the departure avoidance direction is larger than the departure avoidance operation determination threshold dθc (dθ> dθc). That is, when the steering speed dθ in the departure avoidance direction is a certain speed, it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag FDR is set to “ON”.

In cases other than the above, it is determined that the departure avoidance operation is not performed, and the departure avoidance operation flag FDR is set to “OFF”. The departure avoidance operation determination threshold value dθc is an absolute value.
Next, the process proceeds to step S26a, and the target yaw moment correction gain KDR is calculated according to the determination result of the departure avoidance operation in step S25a. This correction gain KDR is set so as to have the characteristics shown in FIG. 11, for example, based on the absolute value | dθ | of the steering speed.

  In FIG. 11, the horizontal axis represents the absolute value | dθ | of the steering speed in the departure avoidance direction, and the vertical axis represents the target yaw moment correction gain KDR. When the absolute value | dθ | of the steering speed is equal to or less than the departure avoidance operation determination threshold value dθc, the correction gain KDR is set to, for example, 100 [%]. When the absolute value | dθ | of the steering speed becomes larger than the deviation avoidance operation determination threshold value dθc, the correction gain KDR decreases in inverse proportion to the increase, and in a region where the absolute value | dθ | of the steering speed is relatively large. The correction gain KDR is set to 0 [%]. That is, the larger the absolute value | dθ | of the steering speed, the larger the vehicle posture change expected by the steering operation. In this case, the target yaw moment Msb is suppressed to be smaller.

Next, the process proceeds to step S27, where the target yaw moment Msb calculated in step S24 is multiplied by the correction gain KDR calculated in step S26a to obtain a target yaw moment correction value Ms.
Next, the process proceeds to step S28, and thereafter, the target braking fluid pressure Psi is calculated in the same procedure as in the third embodiment, and is output to the braking fluid pressure control circuit 7 (step S29).

That is, in the form of this reference example 3 , when the steering operation is performed at a certain steering speed in the departure avoidance direction, it is determined that the driver has performed the departure avoidance operation, and the target yaw moment Msb is suppressed. At this time, since the correction gain KDR is set to a smaller value and the target yaw moment Msb is suppressed to a smaller value as the steering speed is higher, the steering posture is larger and the vehicle posture change expected by the steering operation is larger. The target yaw moment Msb can be suppressed to a smaller value as occasion demands. Therefore, in this case as well, excessive departure avoidance control can be accurately suppressed, and the driver can be prevented from feeling uncomfortable.

Here, in the form of the reference example 3 , the arithmetic processing in FIG. 10 corresponds to the departure avoidance control means, the processing in step S25a corresponds to the departure avoidance operation detection means, and the processing in steps S26a and S27 corresponds to the departure avoidance control. Corresponding to the amount correction means, the steering angle sensor 19 corresponds to the steering angle detection means. Further, in the process of step S25a, the process of calculating the steering speed dθ from the steering angle θ corresponds to the steering speed detection means, and the process of determining whether or not the steering avoidance operation has been performed based on the steering speed dθ in step S25a. Corresponds to the second avoidance operation determination means. Further, the process of step S26a corresponds to the gain setting means, and the processes of step S24, step S28 and step S29 correspond to the yaw moment generating means.

Next, the form of Reference Example 4 will be described.
Since the form of this reference example 4 is the same as that of the said 1st Embodiment except that the process sequence of the arithmetic processing performed by the control unit 8 differs, detailed description of the same part is abbreviate | omitted.
FIG. 12 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by the control unit 8 in the form of the reference example 4 .

  The processing from step S31 to step S34 in FIG. 12 is the same as the processing from step S1 to step S4 in FIG. 2 in the first embodiment, and various data are read (step S31), and the estimated lateral displacement in the future. Xs is calculated (Step S32), the estimated lateral displacement Xs is compared with the departure judgment threshold value Xc to make a departure judgment and the departure direction is specified (Step S33), and the target yaw moment Msb is determined according to the departure judgment result. Is calculated (step S34).

  Next, the process proceeds to step S35, and a second departure avoidance operation determination is performed. This second departure avoidance operation determination is performed in the same procedure as the process of step S5a in FIG. 7, and is determined from the departure direction specified in step S33 and the steering speed dθ in the departure avoidance direction. That is, when the departure determination flag FLD is “LEFT” and the steering speed dθ is smaller than the departure avoidance operation determination threshold −dθc (dθ <−dθc), it is determined that the driver has performed the departure avoidance operation. The departure avoidance operation flag FDR1 is set to “ON”. Further, when the departure determination flag FLD is “LEFT” and the steering speed dθ is larger than the departure operation determination threshold value dθc (dθ> dθc), it is determined that the driver has performed the departure avoidance operation, and the departure avoidance operation flag Set FDR1 to "ON". In cases other than the above, the departure avoidance operation flag FLD is set to “OFF” because the departure avoidance operation is not performed.

If it is determined that the departure avoidance operation has been performed as a result of the departure avoidance operation, the process proceeds to step S36, where a predetermined value dMs1 set in advance is set as the target yaw moment decrease rate dMs.
On the other hand, when it is not determined in step S35 that the departure avoidance operation has been performed, the process proceeds to step S37, and the first departure avoidance operation determination is performed. This first departure avoidance operation determination is the same as the processing in step S5 in FIG. 2, and the departure determination flag FLD is switched from “OFF” to “LEFT” or from “OFF” to “RIGHT” in step S33. Based on the steering angle θs at the start of the departure avoidance control operation as a reference, the determination is made based on whether the steering angle θs is switched back in the departure avoidance direction with respect to the steering angle θs at the start of the operation.

  When the departure determination flag FLD is “LEFT” and the steering angle θ <the control start steering angle θs, it is determined that the departure avoidance operation has been performed, and the departure avoidance operation flag FDR2 is set to “ON”. Further, when the departure determination flag FLD is “RIGHT” and the steering angle θ> the control start steering angle θs, it is determined that the departure avoidance operation has been performed, and the departure avoidance operation flag FDR2 is set to “ON”. In cases other than the above, it is determined that the departure avoidance operation is not performed, and the departure avoidance operation flag FDR2 is set to “OFF”.

  If it is determined that the departure avoidance operation has been performed as a result of the determination of the presence / absence of the departure avoidance operation, the process proceeds to step S38, and the target yaw moment is determined according to the determination result of the departure determination avoidance operation in step S37. Decrease speed dMs is set. Specifically, when the deviation avoidance operation flag FDR2 is “ON”, the target yaw moment decrease speed dMs is calculated from the control map shown in FIG. In addition, you may set based not only on Fig.4 (a) but on FIG.4 (b) or FIG.4 (c).

On the other hand, when the departure avoidance operation flag FDR2 is “OFF”, the target yaw moment decrease rate dMs is set to zero.
In this way, if the decrease speed dMs is set in step S36 or step S38, the process proceeds to step S39, and the decrease speed dMs set in step S36 or step S38 is determined from the target yaw moment Msb calculated in step S34. Subtraction is performed to obtain a target yaw moment correction value Ms (= Msb−dMs).

Next, the process proceeds to step S40, and thereafter, the target braking fluid pressure Psi is calculated in the same manner as in the first embodiment, and the target braking fluid pressure Psi is output to the braking fluid pressure control circuit 7 ( Step S41).
In this way, the presence / absence of the departure avoidance operation is determined based on the steering speed dθ, and the presence / absence of the departure avoidance operation is determined based on the steering angle θ, so that it is determined that the departure avoidance operation is not performed because the steering speed dθ is small. Even when the steering angle θ is turned back in the departure avoidance direction with respect to the steering angle θs at the start of the departure avoidance control operation, this is avoided when the steering operation is performed in the departure avoidance direction. As the operation is being performed, the target yaw moment Msb can be suppressed, and the presence / absence of the driver's departure avoidance operation can be detected more accurately.

  Accordingly, in this case as well, it is possible to avoid excessive deviation prevention control due to the overlap of the vehicle attitude change caused by the driver's deviation avoidance operation and the vehicle attitude change caused by the deviation prevention control, and the steering speed dθ can be reduced. Since it is determined whether or not there is a departure avoidance operation based on both the departure avoidance operation determination based on the steering angle θ and the departure avoidance operation determination based on the steering angle θ, it is possible to more accurately avoid excessive departure prevention control. .

In the embodiment of the reference example 4, the case where the first embodiment and the embodiment of the reference example 1 are combined has been described. However, the present invention is not limited to this. Any of the first to third embodiments in which the presence / absence of the departure avoidance operation is determined based on the steering angle θ, and the reference example in which the presence / absence of the departure avoidance operation is determined based on the steering speed dθ. 1 to any one of the forms of Reference Example 3 are combined, the presence / absence of a departure avoidance operation is determined based on the steering angle θ and the steering speed dθ, and based on this, the decrease speed dMs is calculated, and thereby the target yaw moment Msb is calculated. The target yaw moment correction value Ms may be calculated after correction. Further, the correction gain KDR may be calculated according to the return amount of the steering angle θ, and the target yaw moment correction value Ms may be calculated based on the correction gain KDR. Further, for example, a duration measuring means for measuring an elapsed time from the time when the departure avoidance operation flag FDR is “ON” is provided, and the decreasing speed dMs is set to increase as the measurement time becomes longer. Also good.

In each of the above embodiments, the case where the yaw moment generating means that avoids the departure by generating the yaw moment in the host vehicle has been described as the departure prevention control means, but the present invention is not limited to this. Not. For example, it can be applied to deceleration control means that decelerates the host vehicle when the departure is detected and reduces the speed until the vehicle actually deviates, and any method can be used as long as the departure can be avoided. Even can be applied .

Here, in the form of the reference example 4 , the calculation process of FIG. 12 corresponds to the departure avoidance control unit, the processes of step S35 and step S37 correspond to the departure avoidance operation detection unit, and step S36, step S38, step S39. This process corresponds to the deviation avoidance control amount correcting means, and the steering angle sensor 19 corresponds to the steering angle detecting means. Further, when the deviation determination result FLD is changed from “OFF” to “LEFT” or changed from “OFF” to “RIGHT” in the process of step S33, the steering angle θ at this time is controlled by the deviation avoidance control. The process of storing the steering angle θs at the start of operation in a predetermined storage area corresponds to the steering angle holding means, and the departure avoidance operation is performed using the steering angle θs at the start of the departure avoidance control operation in the process of step S37. The process of determining whether or not has corresponded to the first avoidance operation determination means. Further, in the process of step S35, the process of calculating the steering speed dθ from the steering angle θ corresponds to the steering speed detection means, and in the process of step S35, it is determined whether the steering avoidance operation has been performed based on the steering speed dθ. This processing corresponds to the second avoidance operation determination means. Further, the process of step S38 corresponds to the decrease speed setting means, and the processes of step S34, step S40, and step S41 correspond to the yaw moment generating means.

It is a schematic block diagram which shows an example of the vehicle carrying the lane departure prevention apparatus in this invention. It is a flowchart which shows an example of the process sequence of the arithmetic processing performed with the control unit of FIG. It is an example of the control map used by the arithmetic processing of FIG. It is a flowchart which shows an example of the process sequence of the arithmetic processing performed by the control unit in 2nd Embodiment. It is a flowchart which shows an example of the process sequence of the arithmetic processing performed by the control unit in 3rd Embodiment. It is an example of the control map used by the arithmetic processing of FIG. It is a flowchart which shows an example of the process sequence of the arithmetic processing performed by the control unit in the form of the reference example 1 . It is an example of the control map used by the arithmetic processing of FIG. It is a flowchart which shows an example of the process sequence of the arithmetic processing performed by the control unit in the form of the reference example 2 . 10 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by a control unit in the form of Reference Example 3 . It is an example of the control map used by the arithmetic processing of FIG. 15 is a flowchart illustrating an example of a processing procedure of arithmetic processing executed by a control unit in the form of Reference Example 4 .

Explanation of symbols

5FL to 5RR Wheel 6FL to 6RR Wheel cylinder 7 Braking fluid pressure control circuit 8 Control unit 9 Engine 12 Drive torque control unit 13 Monocular camera 14 Camera controller 15 Acceleration sensor 16 Yaw rate sensor 17 Master cylinder pressure sensor 18 Accelerator opening sensor 19 Steering angle Sensor 20 Direction indication switch 22FL to 22RR Wheel speed sensor

Claims (9)

In the lane departure prevention device provided with the departure avoidance control means for performing departure avoidance control so as to avoid this departure when the host vehicle tends to depart from the traveling lane,
Steering angle detection means for detecting the steering angle;
Steering angle holding means for holding a steering angle at the start of control, which is a steering angle detected by the steering angle detecting means at the start of control intervention by the deviation avoidance control means;
When the detected steering angle detected by the steering angle detection means is within an angular range in a direction that avoids a deviation from the steering angle at the start of control held by the steering angle holding means. A deviation avoidance operation detecting means for detecting that an operation for avoiding deviation is in progress;
When it is detected by the departure avoidance operation detection means that the driver is performing a departure avoidance operation, the control amount in the departure avoidance control means is not detected by the driver. A lane departure prevention apparatus comprising a departure avoidance control amount correcting means for correcting in a smaller direction. The deviation avoidance operation detecting means is configured such that the detected steering angle is within an angle range in a direction in which the detected steering angle is more avoidable than the steering angle at the start of control, and a deviation amount from the steering angle at the start of control is in advance. 2. The lane departure prevention apparatus according to claim 1, wherein when it is equal to or more than a set threshold value, it is detected that the departure avoidance operation is being performed. 3. The deviation avoidance control amount correction means performs the correction so that the control amount in the departure avoidance control means decreases at a preset decrease rate. The lane departure prevention device according to item. The deviation avoidance control amount correction means includes a reduction speed setting means for setting the reduction speed based on a change state when the steering angle detected by the steering angle detection means changes in a direction to avoid departure. The lane departure prevention apparatus according to claim 3, further comprising: The reduction speed setting means is such that the detected steering angle detected by the steering angle detection means is within an angular range in a direction that avoids deviation from the steering angle at the start of control held by the steering angle holding means. 5. The lane departure according to claim 4, wherein the decrease speed is set so that the decrease speed increases as the deviation between the detected steering angle and the control start steering angle increases. Prevention device. The decrease speed setting means includes duration measurement means for measuring a duration when it is continuously detected that the deviation avoidance operation is being detected by the deviation avoidance operation detection means,
  5. The lane departure prevention apparatus according to claim 4, wherein the decreasing speed is set so that the decreasing speed increases as the duration time detected by the duration measuring means increases. 3. The deviation avoidance control amount correction unit corrects the control amount in the departure avoidance control unit by multiplying by a preset correction gain of 1 or less. The lane departure prevention device according to claim 1. The deviation avoidance control amount correction means includes gain setting means for setting the correction gain,
In the gain setting means, the detected steering angle detected by the steering angle detecting means is within an angle range in a direction that avoids a deviation from the steering angle at the start of control held by the steering angle holding means. 8. The lane departure prevention apparatus according to claim 7, wherein the correction gain is set to a smaller value as the deviation between the detected steering angle and the control start steering angle increases. The lane departure prevention according to any one of claims 1 to 8, wherein the departure avoidance control unit is a yaw moment generation unit that generates a yaw moment in a direction to avoid a departure of the host vehicle. apparatus.

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