JP2000065928A - Vehicle safety devices - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To automatically steer a steering device in order to avoid contact with an oncoming vehicle, by leaving a margin for controlling vehicle behavior by a driver's spontaneous steering, It achieves both the collision avoidance effect of automatic steering and manual steering. The size of the A vehicle behavior detected by the vehicle behavior detection means S _3, and allowance of spontaneous vehicle behavior that may be generated by the steering of the driver set in vehicle behavior allowance setting means M4, the vehicle behavior estimation The vehicle motion state calculating means M based on the magnitude of the vehicle behavior generated when the steering device is steered by the steering control means M3 estimated by the means M5.
6 calculates the vehicle motion state, and when the vehicle motion state exceeds a predetermined state range, the steering amount correction means M7 corrects the steering amount of the steering control means M3. Is generated, and even if new vehicle behavior occurs due to automatic steering, it is possible to leave a margin for further vehicle behavior to be generated by the driver's spontaneous collision avoidance operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving safety device for a vehicle which uses an object detecting means such as a radar device to prevent the vehicle from contacting an oncoming vehicle.

[0002]

2. Description of the Related Art Such a vehicle safety device is disclosed in Japanese Patent Application Laid-Open
It is already known from -14100.

[0003] The above-mentioned publication discloses that when the own vehicle may enter the oncoming lane and collide with the oncoming vehicle,
A warning is issued to prompt the driver to perform a voluntary collision avoidance operation, and a collision with an oncoming vehicle that automatically brakes the vehicle is avoided.

[0004]

However, since the above-mentioned prior art does not automatically steer the steering device of the own vehicle in order to avoid a collision with an oncoming vehicle, the driver performs steering to avoid the collision. When the vehicle is not spontaneously performed or the oncoming vehicle does not perform the collision avoidance operation, it is conceivable that the collision cannot be avoided even if the own vehicle is stopped by the automatic braking.
Therefore, it is conceivable to automatically steer the steering system of the own vehicle in order to avoid a collision, but if the vehicle behavior has already changed in the own vehicle at that time, the change in the vehicle behavior due to the automatic steering is considered. In addition, undesired changes in vehicle behavior may occur, which may affect subsequent driving operations of the driver.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is directed to a system for automatically steering a steering device in order to avoid contact with an oncoming vehicle. It is an object of the present invention to achieve both a collision avoidance effect by the automatic steering and a manual steering by leaving a margin for performing the operation.

[0006]

In order to achieve the above object, the invention described in claim 1 comprises an object detecting means for detecting an object present in the traveling direction of the own vehicle, and a detecting means for detecting a vehicle speed of the own vehicle. A vehicle speed detecting means that determines an oncoming vehicle based on a detection result of the object detecting means and a vehicle speed of the own vehicle detected by the vehicle speed detecting means, and includes a relative position, a relative distance, and a relative speed between the own vehicle and the oncoming vehicle. A relative relationship calculating unit that calculates a relative relationship, a contact possibility determining unit that determines a possibility of contact between the own vehicle and the oncoming vehicle based on the relative relationship calculated by the relative relationship calculating unit, and a contact possibility determining unit. Steering control means for automatically steering the steering device of the own vehicle to avoid contact when it is determined that there is a possibility of contact, vehicle behavior detecting means for detecting the magnitude of the vehicle behavior of the own vehicle, driver A vehicle behavior allowance setting means for setting a margin amount of the vehicle behavior can be generated by spontaneous steering,
A vehicle behavior estimating means for estimating the magnitude of the vehicle behavior of the own vehicle when the steering device is steered by the steering control means; and a steering operation based on outputs of the vehicle behavior detecting means, the vehicle behavior margin setting means and the vehicle behavior estimating means. A vehicle motion state calculating means for calculating a vehicle motion state when the steering device is steered by the control means; and a steering operation by the steering control means when the vehicle motion state calculated by the vehicle motion state calculating means exceeds a predetermined state range. And a steering amount correcting means for correcting the steering amount of the device.

According to the above configuration, the magnitude of the vehicle behavior of the own vehicle detected by the vehicle behavior detecting means, the margin of the vehicle behavior which can be generated by the driver's voluntary steering set by the vehicle behavior margin setting means, and When the steering device is steered by the steering control means estimated by the vehicle behavior estimation means, the vehicle motion state calculation means calculates the vehicle motion state based on the magnitude of the vehicle behavior of the own vehicle. Since the steering amount correction means corrects the steering amount of the steering device by the steering control means when the state exceeds the state range, the vehicle behavior has already occurred at the start of the automatic steering, and a new vehicle is started by the start of the automatic steering. Even if the behavior occurs, the driver's voluntary collision avoidance operation can leave room for further vehicle behavior, which allows automatic operation when avoiding contact with oncoming vehicles. It is possible to achieve both the spontaneous collision avoidance operation of a driver and.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, based on the relative relationship calculated by the relative relationship calculating means and a predetermined appropriate lateral distance, the own vehicle is determined as an oncoming vehicle. A proper course setting means for setting a proper course of the own vehicle for passing each other properly, and a contact position predicting means for predicting a contact predicted position at which the own vehicle contacts an oncoming vehicle based on the relative relationship and the vehicle speed of the own vehicle. The contact possibility determining means compares the predicted contact position with the appropriate course to determine the contact possibility of the own vehicle and the oncoming vehicle.

According to the above configuration, the proper course of the own vehicle is set based on the relative relationship calculated by the relative relationship calculating means and the predetermined appropriate lateral distance so that the own vehicle can pass the oncoming vehicle properly. Estimating a predicted contact position at which the own vehicle comes into contact with the oncoming vehicle based on the relative relationship and the vehicle speed of the own vehicle, and comparing the predicted contact position with the appropriate course of the own vehicle to determine the possibility of contact between the own vehicle and the oncoming vehicle. Is determined, the contact possibility can be determined at the time when the oncoming vehicle is determined by the object detecting means without continuously detecting the relative relationship between the own vehicle and the oncoming vehicle by the object detecting means. As a result, it is possible to effectively avoid a head-on collision in which the relative speed of the own vehicle and the oncoming vehicle is large and there is not enough time until contact.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the predetermined state range is an allowable steering amount determined according to a vehicle speed of the own vehicle, and When the steering amount calculated by the calculation means exceeds the maximum value of the allowable steering amount, the steering amount correction means sets the steering amount to the maximum value.

According to the above configuration, when the steering amount calculated by the vehicle motion state calculating means exceeds the maximum allowable steering amount, the steering amount is reduced, so that excessive steering is required so that the driver needs to change the steering wheel. It is possible to prevent the amount from being generated and to ensure steering operability.

According to a fourth aspect of the present invention, in addition to the configuration of the first or second aspect, the predetermined state range is an allowable lateral acceleration determined according to a vehicle speed of the own vehicle, and the vehicle motion state When the lateral acceleration calculated by the calculating means exceeds the maximum value of the allowable lateral acceleration, the steering amount correcting means reduces the steering amount.

According to the above construction, when the lateral acceleration calculated by the vehicle motion state calculating means exceeds the maximum value of the allowable lateral acceleration, the steering amount is reduced, so that the driver's steering can be performed without generating excessive lateral acceleration in the vehicle. , The vehicle behavior can be generated.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the allowable lateral acceleration is such that the rate of increase of the steering amount rapidly increases with respect to the increase of the lateral acceleration in the vehicle turning characteristics. Is set based on the value of.

According to the above configuration, the allowable lateral acceleration is set based on the value of the lateral acceleration at which the rate of increase of the steering amount sharply increases with respect to the increase of the lateral acceleration in the vehicle turning characteristics. Vehicle behavior can be generated.

According to a sixth aspect of the present invention, in addition to the first or second aspect, the predetermined state range is an allowable lateral acceleration determined according to a driving wheel torque of the own vehicle.
When the lateral acceleration calculated by the vehicle motion state calculating means exceeds the maximum value of the allowable lateral acceleration, the steering amount correcting means reduces the steering amount.

According to the above configuration, when the lateral acceleration calculated by the vehicle motion state calculating means exceeds the maximum value of the allowable lateral acceleration determined according to the driving wheel torque of the own vehicle, the steering amount is reduced. A margin can be left in the lateral force of the tire for generating the vehicle behavior in response.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 21 show an embodiment of the present invention. FIG. 1 is an overall structural view of a vehicle provided with a driving safety device.
2 is a block diagram of a driving safety device, FIG. 3 is a perspective view of a steering device of a vehicle, FIG. 4 is an explanatory diagram of functions of an electronic control unit,
FIG. 5 is a block diagram showing a circuit configuration of the electronic control unit.
6 is a flowchart of a main routine, FIG. 7 is a flowchart of a frontal collision avoidance control routine, FIG. 8 is a flowchart of a turning collision avoidance control routine, FIG. 9 is a flowchart of a frontal collision determination routine, FIG. 10 is a flowchart of an alarm control routine, FIG. 11 is a flowchart of an avoidance steering control routine, FIG. 12 is a diagram showing the content of collision avoidance control during turning, FIG. 13 is an explanatory diagram of a method of calculating a lateral deviation δd (when a collision occurs), and FIG. FIG. 15 is an explanatory diagram of a method for calculating δd (when the own vehicle passes on the left side of the oncoming vehicle), and FIG. 15 is an explanatory diagram of the method for calculating the lateral deviation δd (when the own vehicle passes on the right side of the oncoming vehicle). 16 is the lateral deviation δ
d is a map for searching for a correction coefficient, FIG. 17 is an explanatory diagram of a method for calculating a target steering angle for collision avoidance, FIG. 18 is a map for searching for a steering angle correction value δ (θ), and FIG. FIG. 2 is a diagram showing a map or the like for explaining a correction method, and FIG.
0 is a block diagram of a control system of the actuator, and FIG. 21 is a flowchart of an excessive control determination routine.

As shown in FIGS. 1 and 2, a vehicle having left and right front wheels Wf, Wf and left and right rear wheels Wr, Wr has a steering wheel for steering left and right front wheels Wf, Wf which are steering wheels. 1 and an electric power steering device 2 for generating a steering force for assisting the driver in operating the steering wheel 1 and a steering force for collision avoidance. The electronic control unit U that controls the operation of the electric power steering device 2 is input to the steering device 1, the radar device 3 as an object detection unit, the steering angle sensor S ₁ that detects the steering angle of the steering wheel 1, and the steering wheel 1. a steering Tokurusensa S ₂ for detecting a steering torque, a lateral acceleration sensor S ₃ for detecting the lateral acceleration of the vehicle body, a vehicle yaw rate sensor S ₄ for detecting a vehicle yaw rate, the wheels Wf, Wf; Wr, Wr rotation Signals from the vehicle speed sensors S ₅ ... Electronic control unit U constituting frontal collision prevention ECU
The radar device 3, each of the sensors S ₁ to S ₅ ..., engine ECU6 and automatic transmissions EC
The operation of the electric power steering device 2 is controlled based on the signal from U7, and the operation of the display 4 composed of a liquid crystal display and the alarm 5 composed of a buzzer and a lamp are controlled.

The radar device 3 transmits an electromagnetic wave toward a predetermined range in the left and right direction in front of the vehicle and receives a reflected wave of the electromagnetic wave reflected by the object, thereby detecting the relative distance between the vehicle and the object, Detects the relative speed between the car and the object and the direction of the object. In this embodiment, a millimeter-wave radar capable of detecting the above-mentioned relative relationship between the vehicle and the object by one transmission / reception is used.

FIG. 3 shows the structure of the steering device 11.
The rotation of the steering wheel 1 is transmitted to the rack 1 via a steering shaft 12, a connecting shaft 13 and a pinion 14.
5 and the reciprocating motion of the rack 15 is transmitted to the left and right front wheels Wf, Wf via the left and right tie rods 16, 16. The electric power steering device 2 provided in the steering device 11 includes a drive gear 18 provided on an output shaft of an actuator 17, a driven gear 19 meshing with the drive gear 18, and a screw shaft 20 integrated with the driven gear 19. And a nut 21 meshed with the screw shaft 20 and connected to the rack 15.
Therefore, when the actuator 17 is driven, the driving force is transmitted to the driving gear 18, the driven gear 19, the screw shaft 2
0, nut 21, rack 15 and left and right tie rods 1
It can be transmitted to the left and right front wheels Wf, Wf via the wheels 6, 16.

As shown in FIG. 4, the electronic control unit U includes an electric power steering control means 22, a head-on collision avoidance control means 23, a switching means 24, and an output current determination means 2.
5 is provided. Normally, the switching means 24 is connected to the electric power steering control means 22 side, and the electric power steering device 2 performs a normal power steering function. That is, the steering torque sensor steering torque vehicle speed is calculated based on the output of the S ₂ sensor S ₅ ... output current determining means 25 to a predetermined value corresponding to the vehicle speed calculated based on the output of the actuator 17 The output current to the steering wheel 1 is determined, and the output current is output to the actuator 17 via the drive circuit 26, whereby the operation of the steering wheel 1 by the driver is assisted.
On the other hand, when there is a possibility that the own vehicle collides head-on with the oncoming vehicle, the switching means 24 is connected to the front collision avoidance control means 23 side, and the driving of the actuator 17 is controlled by the front collision avoidance control means 23. Automatic steering is performed to avoid a frontal collision with an oncoming vehicle. The details of the automatic steering will be described later.

Next, the configuration of the frontal collision avoidance control means 23 and an outline of its function will be described with reference to FIG.

The head-on collision avoidance control means 23 includes a relative relation calculation means M1, a contact possibility determination means M2, a steering control means M3, a vehicle behavior margin setting means M4, a vehicle behavior estimation means M5, It comprises a state calculating means M6, a steering amount correcting means M7, an appropriate course setting means M8, and a contact position predicting means M9.

The relative relationship calculating means M1 includes an object detecting means (radar device 3) and a vehicle speed detecting means (vehicle speed sensor S).
₅ ), the relative angle (relative position) θ, the relative distance L, and the relative speed Vs between the own vehicle Ai and the oncoming vehicle Ao.
Is calculated. The proper course setting means M8 sets an original proper course R of the own vehicle Ai so that the own vehicle Ai passes the oncoming vehicle Ao properly. The contact position prediction means M9 predicts a contact position P at which the own vehicle Ai contacts the oncoming vehicle Ao at a contact time when the own vehicle Ai passes the oncoming vehicle Ao. Then, the contact possibility determining means M2 determines the contact position P with the appropriate course R
Then, the possibility of contact between the own vehicle Ai and the oncoming vehicle Ao is determined. When the contact possibility determining means M2 determines that the own vehicle Ai may come into contact with the oncoming vehicle Ao, the steering control means M3 controls the steering device 1 of the own vehicle Ai to avoid the contact.
Activate 1

The vehicle behavior margin setting means M4 sets a vehicle behavior margin required when the driver performs a voluntary contact avoidance operation to avoid contact between the own vehicle Ai and the oncoming vehicle Ao. The vehicle behavior estimation means M5 estimates the magnitude of the vehicle behavior of the own vehicle when the steering device 11 is steered by the steering control means M3. Vehicle motion state calculation means M
Reference numeral 6 denotes a steering control unit based on the vehicle behavior that has already occurred in the vehicle Ai, the vehicle behavior set by the vehicle behavior margin setting unit M4, and the vehicle behavior estimated by the vehicle behavior estimation unit M5. The vehicle motion state is calculated as the total vehicle behavior when the steering device 11 is steered by M3. Then, the steering amount correction means M7 corrects the steering amount δh to be output to the steering device 11 in order to secure the necessary vehicle motion margin when the vehicle motion state exceeds a predetermined state range. The operation of the present embodiment will be described in detail with reference to the flowcharts of FIGS. 6 to 11 and the flowchart of FIG.

First, step S of the main routine shown in FIG.
At 11, the state of the own vehicle is detected based on the outputs of the steering angle sensor S ₁ , the steering torque sensor S ₂ , the lateral acceleration sensor S ₃ , the own vehicle yaw rate sensor S _4, and the vehicle speed sensor S ₅ .
In the following step S12, the state of the oncoming vehicle is detected by the radar device 3. The radar device 3 is not only the oncoming vehicle but also the preceding vehicle,
Although a pedestrian bridge, a sign, a cat's eye, and the like are detected, an oncoming vehicle can be identified from other objects based on the relative speed with the own vehicle. In the following step S13, the state of the own vehicle and the state of the oncoming vehicle are displayed on the display 4.

In the following step S14, it is checked whether or not the head-on collision avoidance control is properly performed based on the detection results of the radar device 3 and the sensors S _{1 to} S ₅ . The frontal collision avoidance control is executed only when the driver is not traveling excessively. For example, when traveling at overspeed, the operation of the system is stopped in step S15, and the driver is notified by the display 4 to that effect. Notify and encourage appropriate driving. Step S14
As a result of the system check, when it is detected that the driver has performed a voluntary steering operation to avoid a frontal collision with the oncoming vehicle, the frontal collision avoidance control is stopped in step S16 and the normal electric power The control returns to the steering control, and the driver is notified of the fact by the display 4. Thus, it is possible to prevent the driver's spontaneous steering operation from interfering with the automatic steering control of the head-on collision avoidance control.

If the result of the system check in step S14 is normal, the running state of the own vehicle is determined in step S17. The own vehicle is in a running state close to straight ahead, the time when the vehicle passes (collides) with the oncoming vehicle based on the detection results of the radar device 3 and the sensors S _{1 to} S ₅ , and the positions of the own vehicle and the oncoming vehicle If the relationship can be accurately estimated, the process shifts to step S18 to execute the frontal collision avoidance control. On the other hand, although the vehicle is not traveling excessively, the turning degree of the own vehicle is strong, and the time when the vehicle passes (collides) with the oncoming vehicle,
If the positional relationship between the own vehicle and the oncoming vehicle at that time cannot be accurately estimated, the process proceeds to step S19 to execute the turning collision avoidance control. Then, in step S20, the actuator 17 of the electric power steering device 2 is operated based on the front collision avoidance control or the turning collision avoidance control in order to avoid a collision between the own vehicle and the oncoming vehicle.

Next, the contents of the "frontal collision avoidance control" of step S18 will be described with reference to the flowchart of FIG.

First, in step S21, a collision determination parameter indicating the degree of possibility of collision between the own vehicle and the oncoming vehicle is determined.
That is, the lateral deviation δd between the own vehicle and the oncoming vehicle at the time when the own vehicle and the oncoming vehicle pass each other (or the time when the vehicle collides) is calculated. Then, in step S22, the presence / absence of a collision is determined by comparing the lateral deviation δd with a threshold value to be described later. If there is a possibility of collision and the possibility is small, the alarm device 5 is set in step S23. To alert the driver. If there is a possibility of collision and the possibility is high, a warning is issued and the actuator 17 is driven in step S24 to execute automatic steering for avoiding an oncoming vehicle. Step S2
No. 2 “collision judgment”, Step S23 “warning control”
The specific contents of the “avoidance steering control” in step S24 will be described later in detail with reference to FIGS. 9, 10, and 11.

Next, the contents of the "turning collision avoidance control" in step S19 will be described with reference to the flowchart of FIG.

First, in step S31, the collision risk during turning is calculated. As shown in FIG. 12, the collision risk is determined based on the difference between the turning radius of the own vehicle and the turning radius of the oncoming vehicle, and the risk is determined to be higher as the difference increases. . Then, in step S32, the warning control and the lane departure prevention control according to the collision risk are executed. At the time of turning, it is difficult to accurately estimate the time of passing (collision) with the oncoming vehicle and the positional relationship between the own vehicle and the oncoming vehicle at that time, so that the collision avoidance control is weaker than that of straight ahead. .

As shown in FIG. 12, the collision risk during turning is set at three levels, Level 1, Level 2 and Level 3. For example, in the case of left-hand traffic, the vehicle turns right. If the vehicle is turning, the determination is made based on the turning radius of the oncoming vehicle minus the turning radius of the own vehicle. If the vehicle is turning left, the determination is made based on the turning radius of the own vehicle minus the turning radius of the oncoming vehicle. At level 1 where the degree of danger is low, only the alarm by the alarm 4 is executed, and at level 2 where the degree of danger is medium, an alarm by the alarm 4 and weak lane departure prevention control by the actuator 17 are executed, and level 3 where the degree of danger is high Then, the warning by the alarm 4 and the strong lane departure prevention control by the actuator 17 are executed. The lane departure prevention control prevents the lane departure by driving the actuator 17 of the electric power steering device 2 to generate a steering reaction force that hinders the steering when the driver performs steering in a direction deviating from the lane. Is what you do.

It should be noted that the warning in the "collision avoidance control during turning" is distinguished from the warning in the "front collision avoidance control".
The tone color of the buzzer and the color of the lamp of the alarm 5 are made different.

Next, the "collision judgment" in step S22 is performed.
Are described in the flowchart of FIG. 9 and FIGS.
A description will be given based on the explanatory diagram of FIG.

First, at step S41, vehicle speed sensors S ₅ .
Calculating a vehicle speed Vi of the vehicle Ai based on the output, calculates a yaw rate γi of the vehicle Ai based on the output of the vehicle yaw rate sensor S ₄ at step S42, based on the output of the radar device 3 at step S43 Own car Ai and oncoming car Ao
Is calculated based on the output of the radar device 3 in step S44, and the relative speed Vs between the own vehicle Ai and the oncoming vehicle Ao is calculated in step S44. Is calculated with respect to the oncoming vehicle Ao. In a succeeding step S46, an original proper course R of the own vehicle Ai to pass without colliding with the oncoming vehicle is set based on the appropriate lateral distance da measured from the current position of the oncoming vehicle Ao. The appropriate lateral distance da is set in advance, and its value is, for example, 3 m. In a succeeding step S47, the yaw rate γo of the oncoming vehicle Ao is calculated from the vehicle speed Vi and the yaw rate γi of the own vehicle Ai and the relative positional relationship of the oncoming vehicle Ao with respect to the own vehicle Ai. Then, in step S48, the lateral deviation δd between the own vehicle Ai and the proper course R at the position where the own vehicle Ai passes the oncoming vehicle Ao (contact position P) is calculated. Hereinafter, the process of calculating the lateral deviation δd will be described in detail with reference to FIG.

FIG. 13 shows a state in which the host vehicle Ai tries to accidentally enter the lane of the oncoming vehicle Ao on the left-hand traffic road. Here, the proper lateral position Ai 'is a position on the proper course R of the own vehicle Ai and corresponding to the lateral direction of the current position of the oncoming vehicle Ao.
The distance from the distance o is an appropriate lateral distance da (for example, 3 m). L is the relative distance between the own vehicle Ai and the oncoming vehicle Ao, and is calculated based on the output of the radar device 3. θ is the vehicle A
It is a relative angle between i and the oncoming vehicle Ao, and is calculated based on the output of the radar device 3. ε is the proper course R of the vehicle Ai
And the direction of the oncoming vehicle Ao, and is obtained geometrically based on the relative distance L and the appropriate lateral distance da. Vi is the vehicle speed of the own vehicle Ai, and the vehicle speed sensor S
₅ Calculated based on the output of. Vs is a relative vehicle speed corresponding to a difference between the vehicle speed Vi of the own vehicle Ai and the vehicle speed Vo of the oncoming vehicle Ao, and is calculated based on the output of the radar device 3.

In FIG. 13, in the hatched triangle, X cos (θ + ε) = L sin θ (1) is established. When this is solved for X, X = L sin θ / cos (θ + ε) (2) Is obtained. The contact time tc measured based on the present time
(Elapsed time until passing time or collision time)
It is obtained as a value obtained by dividing the relative distance L by the relative speed Vs.

Tc = L / Vs (3) The distance Lc from the host vehicle Ai to the contact position P (passing position or collision position) is obtained as a product of the vehicle speed Vi and the contact time tc.

Lc = Vi · tc = L (Vi / Vs) (4) As is apparent from FIG. 13, the similarity between two right triangles sharing the vertex of the angle θ + ε at the position of the vehicle Ai is given by Lc ': L = δd: da + X (5) holds, and from the relationship of Lc ′ cosε = Lc cos (θ + ε) and the above equations (2), (4) and (5),
The lateral deviation δd is obtained as in the following equation.

[0043]

(Equation 1)

Of the five variables on the right side of equation (6), Vi can always be calculated, and Vs, L, θ, ε
Can be calculated by one transmission / reception of the radar device 3, so that the lateral deviation δd can be calculated promptly when the oncoming vehicle Ao is first determined by the radar device 3. Accordingly, even when the own vehicle Ai and the oncoming vehicle Ao approach each other, there is no room for the contact time tc, and it is possible to quickly determine the possibility of contact and start the collision avoidance control.

Then, in step S49 of the flowchart of FIG. 9, the lateral deviation δd is compared with a preset contact judgment reference value, and the lateral deviation δd is compared with the first contact judgment reference value δdn and the second contact judgment reference value. If it is between δdx, that is, if δdn <δd <δdx is satisfied, it is determined in step S50 that the own vehicle Ai may collide with the oncoming vehicle Ao (see FIG. 13). On the other hand, as shown in FIG.
dn or δd ≧ δd as shown in FIG.
If x, it is determined in step S51 that there is no possibility that the own vehicle Ai will collide with the oncoming vehicle Ao. The state shown in FIG. 15 corresponds to, for example, a case where the own vehicle Ai crosses the lane of the oncoming vehicle Ao diagonally to enter the branch road.

The first contact judgment reference value δdn and the second contact judgment reference value δdx are appropriately set according to the vehicle width of the host vehicle Ai, and are, for example, the first contact judgment reference value δd.
n = 1.5 m, and the second contact determination reference value δdx = 4.5 m.

In the above description, the yaw rate γi of the own vehicle Ai and the yaw rate γo of the oncoming vehicle Ao are not taken into account when calculating the lateral deviation δd.
By considering o, collision avoidance with higher accuracy is performed.

When the vehicle Ai travels at the vehicle speed Vi and the yaw rate γi, a lateral acceleration of Viγi occurs.
The lateral movement amount yi of the vehicle Ai is calculated by integrating γi twice. Therefore, the lateral movement amount yi of the vehicle Ai at the contact time tc = L / Vs is given by yi = (Vi · γi / 2) · (L / Vs) ² (7).

Similarly, when the oncoming vehicle Ao runs at the vehicle speed Vo and the yaw rate γo, a lateral acceleration of Voγo is generated. Therefore, the oncoming vehicle Ao is integrated by integrating this Voγo twice.
Is calculated in the horizontal direction. Therefore, the contact time t
Lateral movement amount yo of oncoming vehicle Ao at c = L / Vs
Is given by: yo = (Vo · γo / 2) · (L / Vs) ² (8)

The lateral deviation δd of the above equation (6) is corrected by the following equation, which is corrected by the lateral movement amount yi of the own vehicle Ai and the lateral movement amount yo of the oncoming vehicle Ao.
Accuracy can be further improved.

[0051]

(Equation 2)

The yaw rate γo of the oncoming vehicle Ao is determined by detecting the position of the oncoming vehicle Ao a plurality of times based on the output of the radar device 3 and estimating the turning trajectory of the oncoming vehicle Ao. It is calculated based on the vehicle speed Vo. Therefore, the yaw rate γo of the oncoming vehicle Ao cannot be detected by one transmission / reception of the laser device 3, and it takes some calculation time to perform the correction using the yaw rate γo of the oncoming vehicle Ao in equation (9). become. However, as described in step S17 of the flowchart in FIG. 6, the frontal collision avoidance control is performed when the vehicle Ai is traveling substantially straight (when traveling on a straight road). At this time, the yaw rate γo of the oncoming vehicle Ao rarely has a large value. From this, the yaw rate γ of the oncoming vehicle Ao
Sufficient accuracy can be ensured without performing correction using o.

Incidentally, the first contact determination reference value δdn
And the first contact determination reference value δdn and the second contact determination reference value δdx are replaced with the fixed value of the second contact determination reference value δdx.
If the correction is made in the traveling state of the oncoming vehicle Ao, the frontal collision avoidance control can be performed with higher accuracy. That is, the first contact determination reference value δdn is corrected by three correction coefficients k1
Using n, k2n, and k3n, δdn ← k1n · k2n · k3n · δdn (10), and the correction of the second contact determination reference value δdx is 3
Δdx ← k1x · k2x · k3x · δdx (11) using the three correction coefficients k1x, k2x, and k3x.

The correction coefficients k1n and k1x are shown in FIG.
Are searched based on the time until the collision (contact time tc) from the map shown in FIG. In the region where the calculation error of the lateral deviation δd is estimated to be small due to the short contact time tc, the correction coefficients k1n and k1x are held at 1. In a region where the calculation error of the lateral deviation δd is estimated to be large because the contact time tc is large, the correction coefficient k1n increases from 1 with the increase of the contact time tc, and the correction coefficient k1x increases with the increase of the contact time tc. Accordingly, it decreases from 1. Thereby, the first contact determination reference value δ is calculated in a region where the calculation error of the lateral deviation δd is large.
By reducing the width between dn and the second contact determination reference value δdx, it is possible to avoid performing uncertain frontal collision avoidance control.

The correction coefficients k2n and k2x are shown in FIG.
The relative distance L between the own vehicle Ai and the oncoming vehicle Ao from the map shown in FIG.
Is searched based on In an area where the calculation error of the lateral deviation δd is estimated to be small due to the small relative distance L, the correction coefficients k2n and k2x are held at 1. In a region in which the calculation error of the lateral deviation δd is estimated to be large because the relative distance L is large, the correction coefficient k2n increases from 1 with an increase in the relative distance L, and the correction coefficient k2x becomes the relative distance L
Decreases from 1 with the increase of. This gives the lateral deviation δ
In the region where the calculation error of d is large, the first contact determination reference value δdn
And the width between the second contact determination reference value δdx and
Uncertain frontal collision avoidance control can be avoided.

The correction coefficients k3n and k3x are shown in FIG.
Is searched based on the yaw rate γi of the vehicle Ai. When the yaw rate γi of the vehicle Ai is 0 and the calculation error of the lateral deviation δd is estimated to be small, the correction coefficients k3n and k3x are set to 1. When the calculation error of the lateral deviation δd increases with an increase in the yaw rate γi of the vehicle Ai, the correction coefficient k3n increases from 1 and the correction coefficient k3x decreases from 1. This gives the lateral deviation δ
In the region where the calculation error of d is large, the first contact determination reference value δdn
And the width between the second contact determination reference value δdx and
Uncertain frontal collision avoidance control can be avoided.

Next, the "alarm control" of step S23 is performed.
Will be described based on the flowchart of FIG.

First, collision information is received in step S61. The collision information includes contact time tc (time until collision),
Traveling state of the own vehicle Ai and the oncoming vehicle Ao at the contact position P,
And the lateral deviation δd. In the subsequent step S62, a primary alarm is determined, and when the contact time tc becomes, for example, less than 4 seconds,
In step S63, the alarm 5 is operated to start a primary alarm. Subsequently, in step S64, a secondary alarm is determined,
If the contact time tc is less than 3 seconds, for example, step S6
At 5, the alarm 5 is activated to start a secondary alarm. The primary warning is performed when the time margin before the collision is relatively large, and the secondary warning is performed when the time margin before the collision is relatively small, so that the difference is recognized by the driver. In order to change the tone of the buzzer and the color of the lamp. The driver recognizes the danger of the collision by the alarm from the alarm device 5 and can perform a voluntary avoidance operation.

Next, the contents of the "avoidance steering control" of step S24 will be described with reference to the flowchart of FIG.

First, in step S71, step S71
After receiving the collision information as in step 61,
At 72, the start of steering is determined, and the contact time tc is set to a threshold value τ ₀ shorter than the secondary alarm threshold value of 3 seconds (for example, 2.
If less than 2 seconds), a lateral movement amount for avoiding collision is calculated in step S73. This lateral movement amount is basically filled with the current value of the lateral deviation δd calculated in step S48, but an averaging process is performed using the previous value to remove an error.

First, in step S74, the vehicle speed V of the own vehicle Ai
Based on i, a target steering angle δh that does not cause a feeling of strangeness to the driver is obtained. As shown in FIGS. 17 (A) and (B), the avoidance movement is performed after the own vehicle Ai avoids the oncoming vehicle Ao.
The reference value of the lateral movement amount at the time when the contact time tc (threshold value τ ₀ ) has elapsed is determined based on the effect of collision avoidance and the fact that the vehicle does not eventually deviate from the lane. Is set to 2 m, for example. Also, the maximum lateral acceleration YG generated by the avoidance steering is too large or the steering speed is too fast so that the driver does not feel uncomfortable, and the lateral movement of 2 m is performed when τ ₀ has elapsed from the start of the steering. Must be. From the above, in the present embodiment, for example, the maximum lateral acceleration YG is set to about 0.15 G, and the steering cycle is set to about 4 seconds (0.25 Hz).

Thus, the target steering angle δh for collision avoidance
Is given by the following equation, where N is the steering gear ratio and Ks is the stability factor.

[0063]

(Equation 3)

The target steering angle δ given by the above equation (12)
In h, if the direction of the relative angle θ between the own vehicle Ai and the oncoming vehicle Ao is directed from the own vehicle Ai to the oncoming vehicle Ao, it may be insufficient to avoid a collision. Therefore, the target steering angle correction value δ (θ) based on the relative angle θ (FIG. 1)
8), the target steering angle δh in the equation (12) is corrected.

[0065]

(Equation 4)

In the following step S75, the target steering angle δh
Is determined to be excessive. As a result, if the target steering angle δh is excessive, the target steering angle δh is corrected to an appropriate value in step S76, and the target steering angle δh
The amount of lateral movement given by the steering in accordance with the correction of the target steering angle δ
A correction is made to decrease by the reduction rate of h. In step S77, the actuator 1 of the steering device 11 is controlled according to the target steering angle δh in order to avoid a collision with the oncoming vehicle Ao.
7 is controlled. That is, as shown in FIG.
The PI controller, to which the deviation between the target steering angle δh and the actual steering angle of the steering device 11 is input, performs feedback control of the actuator 17 of the steering device 11 so as to converge the deviation to zero.

Next, the contents of the "excess control determination" in step S75 will be specifically described based on the flowchart of FIG.

In the present embodiment, by preventing the steering device 11 from being excessively controlled to prevent a collision, the steering operability of the driver is maintained, and the steering of the driver is performed during and after execution of the control. The aim is to secure a sufficient amount of vehicle behavior so that the vehicle responds as intended to the operation. Specifically, the steering angle, the magnitude of the vehicle behavior, and the performance of the tire are selected as parameters. The steering angle is adjusted so that the rotational position of the steering wheel 1 does not change to a position where it is difficult to operate. Regarding the magnitude of the vehicle behavior, it is possible to prevent the occurrence of the lateral acceleration YG that gives a sense of incongruity to the driver, and to limit the magnitude of the lateral acceleration YG to a magnitude that leaves a sufficient margin for steering response. Regarding the performance of the tire, the grip force of the tire not only leaves a margin for the whole vehicle, but also leaves a margin in the grip force for each wheel of the tire.

For this purpose, the vehicle behavior (lateral acceleration YG) detected by the vehicle behavior detecting means S ₃ (lateral acceleration sensor S ₃ ) which has already occurred before the start of control and set by the vehicle behavior margin setting means M4. The automatic steering operation is performed such that the sum of the surplus amount of the vehicle behavior and the vehicle behavior estimated by the vehicle behavior estimation means M5, which is estimated to be generated by the automatic steering for avoiding contact, does not exceed a preset value. Limit the amount,
The vehicle behavior is to leave room for steering responsiveness without giving the driver a sense of incongruity. This allows the driver to voluntarily perform an effective contact avoidance operation with peace of mind.

Step S81 of the flowchart in FIG.
In, it calculates a target steering angle maximum .delta.h ₁ on the basis of a map which is set according to the vehicle speed Vi shown in FIG. 19 (A), is compared with this target steering angle maximum .delta.h ₁ wherein the target steering angle .delta.h . As a result, if a too large target steering angle .delta.h exceeds the target steering angle maximum .delta.h _1, the process proceeds to step S82 corrects for updating the maximum value .delta.h ₁ as a new target steering angle .delta.h. Since the target steering angle δh is set based on the lateral acceleration, when the vehicle speed Vi is low, the target steering angle δh becomes large, so that the driver may have to change the steering wheel 1 in some cases. However, the target steering angle δh is changed to the maximum value δh
By regulating in _1, it can be large steering angle driver that Mochikaeru the steering wheel 1 by the automatic steering can be prevented from occurring, to eliminate the uncomfortable feeling of the driver.

[0071] followed by step S83, the detected lateral acceleration YG based on the output of the lateral acceleration sensor S ₃ constituting the vehicle behavior detection means of the present invention, the target steering angle the lateral acceleration YG as a parameter representative of the vehicle behavior It is determined whether or not δh is appropriate. Thereby, even when the vehicle behavior has already occurred at the start of the collision avoidance control, it is possible to prevent the occurrence of excessive vehicle behavior due to the automatic steering. That is, the total lateral acceleration after the control is YGo, the lateral acceleration generated by the control is YGs, and the lateral acceleration before the control is YGs.
Assuming i, the following equation is established.

YGo = YGs + YGi (14)

[0073]

(Equation 5)

Then, from the map shown in FIG.
Total lateral acceleration YGo set according to vehicle speed Vi
Is searched for the maximum value of YG _MAX . This maximum value YG _MAX is not a limit value at which the occurrence of a vehicle may occur, but a value set as a maximum value to be generated when the frontal collision avoidance device operates.

FIG. 19C shows the relationship between the lateral acceleration and the steering angle when the speed of the vehicle changes while the general vehicle runs on a circle having a constant radius. In a region where the lateral acceleration is small to some extent (linear region), the steering angle increases little by little even if the lateral acceleration increases. However, when the lateral acceleration increases beyond the linear region, the steering angle starts to increase sharply (steering angle). Of the vehicle) and eventually reaches the limit lateral acceleration of the vehicle. In this embodiment, in the linear region, the lateral acceleration Y
Set the maximum value of Go, YG _MAX . Therefore, the lateral acceleration Y
Go even if increased beyond the maximum value YG _MAX, it is possible to secure a sufficient margin to reach the limit lateral acceleration of the vehicle. Thus, as shown in FIG. 19B, the maximum value YG _MAX of the lateral acceleration YGo is set according to the vehicle speed Vi. The reason why the maximum value YG _MAX increases in accordance with the decrease in the vehicle speed Vi is that the driver's adaptability to the lateral acceleration increases during low-speed running.

[0076] From the above, when the lateral acceleration YGo exceeds the maximum value YG _MAX at step S83, the to limit the upper limit value of the target steering angle δh in the maximum value YG _MAX proceeds to step S84 Is corrected. That is, the lateral acceleration YGS ₂ for generating the control after correction is given by _{YGs 2 = YG MAX -YGi ... (} 16), the target steering angle .delta.h ₂ after correction,

[0077]

(Equation 6)

Is given by And the corrected target steering angle
δh_TwoIs the target steering angle δh or the corrected target
Steering angle δh₁If it is smaller, the corrected target steering
Angle δh _TwoIs updated as a new target steering angle δh.
Do.

In the following step S85, it is determined whether or not the tire grip state is appropriate. Here, a general front-wheel drive vehicle is considered. FIG. 19D is a friction ellipse of a tire of a front wheel which is a driving wheel, and a vertical axis and a horizontal axis represent a lateral force and a longitudinal force, respectively. The maximum force that the tire can generate is on the circumference of the ellipse, and when the tire is generating driving force (front-rear force), the maximum lateral force is reduced by that amount. It is necessary to leave a margin in the lateral force of the tire even after the automatic steering so that the driver's avoidance steering works effectively when the frontal collision is avoided. For this reason, when the driving force is large, a limit is imposed so that the maximum lateral force of the tire that can cause automatic steering is not used up. At this time, it is strictly necessary to limit the lateral force of the tire due to automatic steering according to the driving force, but to obtain the lateral force accurately, a sensor that detects the tire's ground load and related arithmetic processing are required Therefore, since the frontal collision avoidance control is performed when the vehicle is substantially traveling straight ahead, the lateral force of the tire is considered to be proportional to the lateral acceleration YG, and the lateral force of the tire is limited. Instead, the lateral acceleration YG is limited.

That is, as shown in FIG.
Lateral acceleration so that it decreases as the ear driving force increases
Maximum value YG of degree YGo_MAXBeforehand, and
In step S85, the lateral acceleration YGo is the maximum value YG_MAXA place beyond
In this case, the process proceeds to step S86, where the maximum value YG_MAX
To correct the upper limit of the target steering angle δh.
U. Corrected target steering angle δh_ThreeCorresponds to the vehicle behavior described above.
Target steering angle δh for performing correction by_Two((1
It can be calculated in the same manner as in (7) Expression). And goals
Steering angle δh_ThreeIs the target steering angle δh or after the correction
Target steering angle δh ₁, Δh_TwoIf it is smaller than
Immediate target steering angle δh_ThreeAs the new target steering angle δh
Make the correction to be updated. Thus, step S8
In step 7, the corrected target steering angle δh is finally determined.

The driving force of the tire can be calculated from the engine torque, the shift position, the torque amplification factor of the torque converter obtained by communication with the engine ECU 6 and the automatic transmission ECU 7, and the radius of the tire known in advance. .

In step S76 of the flowchart of FIG. 11, the lateral movement amount (ie, lateral deviation δd) calculated in step S73 is compared with the corrected target steering angle δ.
h is compared with the amount of lateral movement caused by h. As a result, when the lateral movement amount of the latter is larger than the lateral movement amount of the former, that is, when the lateral movement amount generated by the target steering angle δh is larger than the lateral movement amount necessary for collision avoidance, The target steering angle δh is corrected in a decreasing direction to a value that can obtain a large lateral movement amount. Conversely, when the lateral movement amount of the latter is smaller than the lateral movement amount of the former, that is, when the lateral movement amount generated by the target steering angle δh is smaller than the lateral movement amount necessary for collision avoidance, the target No correction of the steering angle δh is performed. Then, in step S77, the actuator 17 of the steering device 11 is operated so as to obtain the final lateral movement amount.

As described above, by restricting the amount of lateral movement generated by the target steering angle δh so as not to exceed the amount of lateral movement necessary for collision avoidance, the target steering angle δh
Can be prevented from being output and giving a feeling of strangeness to the driver.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

[0085]

As described above, according to the first aspect of the invention, the magnitude of the vehicle behavior of the own vehicle detected by the vehicle behavior detecting means and the driver's spontaneity set by the vehicle behavior margin setting means are set. The vehicle motion state calculation means calculates the vehicle motion state based on the amount of vehicle motion margin that can be generated by the proper steering and the magnitude of the vehicle behavior of the own vehicle when the steering device is steered by the steering control means estimated by the vehicle behavior estimation means. The state is calculated, and when the vehicle motion state exceeds a predetermined state range, the steering amount correcting means corrects the steering amount of the steering device by the steering control means, so that the vehicle behavior already occurs at the start of the automatic steering. Even if new vehicle behavior occurs due to the start of automatic steering, there is room for further vehicle behavior due to the driver's spontaneous collision avoidance operation. It is possible to achieve both the spontaneous collision avoidance operation of the automatic steering and the driver at the time of contact avoidance between.

According to the second aspect of the present invention,
Based on the relative relationship calculated by the relative relationship calculating means and a preset appropriate lateral distance, the own vehicle sets an appropriate course of the own vehicle for appropriately passing the oncoming vehicle,
Based on the relative relationship and the vehicle speed of the own vehicle, a predicted contact position at which the own vehicle comes into contact with the oncoming vehicle is estimated, and the predicted contact position is compared with the appropriate course of the own vehicle to determine the possibility of contact between the own vehicle and the oncoming vehicle. Since the determination is made, the possibility of contact can be determined when the oncoming vehicle is determined by the object detection means without continuously detecting the relative relationship between the own vehicle and the oncoming vehicle by the object detection means. As a result, it is possible to effectively avoid a head-on collision in which the relative speed of the own vehicle and the oncoming vehicle is large and there is not enough time until contact.

According to the third aspect of the present invention,
Since the steering amount is reduced when the steering amount calculated by the vehicle motion state calculation means exceeds the maximum value of the allowable steering amount, it is possible to prevent an excessive steering amount from being generated so that the driver needs to change the steering wheel, Steering operability can be ensured.

According to the fourth aspect of the present invention,
When the lateral acceleration calculated by the vehicle motion state calculating means exceeds the maximum value of the allowable lateral acceleration, the steering amount is reduced, so that the vehicle behavior is generated in response to the driver's steering without generating excessive lateral acceleration in the vehicle. be able to.

According to the invention described in claim 5,
Since the allowable lateral acceleration is set based on the value of the lateral acceleration at which the rate of increase of the steering amount rapidly increases with respect to the increase of the lateral acceleration in the vehicle turning characteristics, accurate vehicle behavior can be generated according to the driver's steering. .

According to the invention described in claim 6,
When the lateral acceleration calculated by the vehicle motion state calculation means exceeds the maximum value of the allowable lateral acceleration determined according to the driving wheel torque of the own vehicle, the steering amount is reduced, so that the vehicle behavior is generated in response to the driver's steering. It can leave a margin in the lateral force of the tire.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle including a driving safety device.

FIG. 2 is a block diagram of a driving safety device.

FIG. 3 is a perspective view of a steering device.

FIG. 4 is an explanatory diagram of functions of an electronic control unit.

FIG. 5 is a block diagram showing a circuit configuration of an electronic control unit.

FIG. 6 is a flowchart of a main routine.

FIG. 7 is a flowchart of a frontal collision avoidance control routine;

FIG. 8 is a flowchart of a turning collision avoidance control routine.

FIG. 9 is a flowchart of a frontal collision determination routine.

FIG. 10 is a flowchart of an alarm control routine.

FIG. 11 is a flowchart of an avoidance steering control routine.

FIG. 12 is a diagram showing details of a collision avoidance control during turning.

FIG. 13 is an explanatory diagram of a calculation method of a lateral deviation δd (when a collision occurs).

FIG. 14 is an explanatory diagram of a calculation method of the lateral deviation δd (when the own vehicle passes the left side of the oncoming vehicle)

FIG. 15 is an explanatory diagram of a calculation method of the lateral deviation δd (when the own vehicle passes the right side of the oncoming vehicle).

FIG. 16 is a map for searching for a correction coefficient of the lateral deviation δd.

FIG. 17 is an explanatory diagram of a calculation method of a target steering angle for avoiding a collision.

FIG. 18 is a map for searching for a target steering angle correction value δ (θ).

FIG. 19 is a diagram showing a map or the like for explaining a method of correcting a target steering angle.

FIG. 20 is a block diagram of a control system of the actuator.

FIG. 21 is a flowchart of an excessive control determination routine.

[Explanation of symbols]

Ai Own vehicle Ao Oncoming vehicle da Appropriate lateral distance L Relative distance M1 Relative relation calculation means M2 Contact possibility determination means M3 Steering control means M4 Vehicle behavior margin setting means M5 Vehicle behavior estimation means M6 Vehicle motion state calculation means M7 Steering amount correction means M8 proper path setting means M9 contact position prediction means P predicted contact position R proper path S ₃ lateral acceleration sensor (vehicle behavior detecting means) S ₅ speed sensor (vehicle speed detecting means) Vi of the vehicle speed Vs relative velocity δh steering angle ( Steering amount) θ relative angle (relative position) 3 radar device (object detection means) 11 steering device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H180 AA01 CC12 CC14 CC27 LL01 LL02 LL04 LL07 LL08 LL09 5J070 AB24 AC01 AC02 AC06 AC11 AE01 AH04 AH14 AH50 AK04 AK14 AK40 BD10 BF02 BF03 BF04 BF10 BF12 BF12 BF12

Claims (6)

[Claims] And 1. A object detecting means for detecting an object present in the traveling direction of the vehicle (Ai) (3), a vehicle speed detecting means for detecting a vehicle speed (Vi) of the vehicle (Ai) (S _5), together determine facing car (Ao) based on the detection result and the vehicle speed detecting means by the object detecting means (3) speed of (S ₅₎ by the detected vehicle (Ai) (Vi), the vehicle (Ai)
Position (θ), relative distance (L) between the vehicle and oncoming vehicle (Ao)
A relative relationship calculating means (M1) for calculating a relative relationship consisting of the vehicle speed (Ai) and the oncoming vehicle (Ao) based on the relative relationship calculated by the relative relationship calculating device (M1). Contact possibility determining means (M2) for determining the possibility of contact; and steering of the vehicle (Ai) to avoid contact when the contact possibility determining means (M2) determines that there is a possibility of contact. Steering control means (M) for automatically steering the device (11).
3), a vehicle behavior detecting means (S ₃ ) for detecting the magnitude of the vehicle behavior of the own vehicle (Ai), and a vehicle behavior margin for setting a margin of the vehicle behavior that can be generated by the driver's spontaneous steering. Setting means (M4)
If, steering system by the steering control means (M3) (11) and the vehicle behavior estimating means for estimating the size of the vehicle behavior the host vehicle (Ai) when steering (M5), vehicle behavior detecting means (S ₃₎ Vehicle motion state calculation for calculating a vehicle motion state when the steering device (11) is steered by the steering control means (M3) based on the outputs of the vehicle behavior margin setting means (M4) and the vehicle behavior estimation means (M5). Means (M6) and a steering amount (δh) of the steering device (11) by the steering control means (M3) when the vehicle motion state calculated by the vehicle motion state calculation means (M6) exceeds a predetermined state range. A driving safety device for a vehicle, comprising: a steering amount correcting unit (M7) for correcting the steering amount. 2. The relative relationship calculated by a relative relationship calculating means (M1) and a predetermined appropriate lateral distance (d
an appropriate course setting means (M8) for setting an appropriate course (R) of the own vehicle (Ai) so that the own vehicle (Ai) passes the oncoming vehicle (Ao) properly based on a); The predicted contact position (P) at which the vehicle contacts the oncoming vehicle (Ao) is determined by the relative relationship and the vehicle speed (V) of the own vehicle (Ai).
contact position prediction means (M9) for predicting based on i),
The contact possibility determining means (M2) compares the predicted contact position (P) with the proper course (R) to determine the contact possibility of the own vehicle (Ai) and the oncoming vehicle (Ao). The driving safety device for a vehicle according to claim 1, wherein the determination is performed. 3. The predetermined state range is an allowable steering amount determined according to a vehicle speed (Vi) of the vehicle (Ai), and the steering amount calculated by the vehicle motion state calculating means (M6) is the allowable steering amount. The vehicle safety device according to claim 1 or 2, wherein the steering amount correction means (M7) sets the steering amount (δh) to the maximum value when the amount exceeds the maximum value. . 4. The predetermined lateral range is an allowable lateral acceleration determined according to a vehicle speed (Vi) of the vehicle (Ai), and the lateral acceleration calculated by the vehicle motion state calculating means (M6) is the allowable lateral acceleration. The driving safety device for a vehicle according to claim 1, wherein the steering amount correction means (M7) decreases the steering amount (δh) when the acceleration exceeds the maximum value. 5. The method according to claim 4, wherein the allowable lateral acceleration is set based on a value of a lateral acceleration at which a rate of increase of a steering amount sharply increases with respect to an increase of a lateral acceleration in a vehicle turning characteristic. A driving safety device for a vehicle according to the above. 6. The predetermined lateral range is an allowable lateral acceleration determined according to a driving wheel torque of the vehicle (Ai), and the lateral acceleration calculated by the vehicle motion state calculating means (M6) is the allowable lateral acceleration. The driving safety device for a vehicle according to claim 1 or 2, wherein the steering amount correction means (M7) decreases the steering amount (δh) when the maximum value is exceeded.