JP5554037B2 - Vehicle contact avoidance support device - Google Patents

Description

  The present invention relates to a vehicle contact avoidance support device, and more particularly to vehicle contact avoidance that performs automatic brake control and steering assist control based on the possibility of contact between the host vehicle and an obstacle in front of the host vehicle (such as a preceding vehicle). The present invention relates to a support device.

  Conventionally, when the relative speed (inter-vehicle distance) and relative speed from an own vehicle to an obstacle in front of the own vehicle (fixed object or preceding vehicle) and relative speed are detected, the vehicle speed of the own vehicle is faster than the vehicle speed of the preceding vehicle In addition, a margin time (contact margin time) TTC (Time To Contact), which is a value obtained by dividing the relative distance by the relative speed and until the vehicle contacts the obstacle, is calculated, and the calculated contact margin time TTC is calculated. There has been proposed an automatic brake control device that automatically generates a braking force in accordance with (Patent Document 1).

  In this case, in the automatic brake control device proposed in Patent Document 1, the overlapping degree of the travel locus defined by the width of the vehicle and the width of the obstacle ahead of the vehicle, the relative speed, and the contact margin are determined. The braking force of automatic brake control is changed according to time. More specifically, control is performed so that the braking force of the automatic brake decreases as the degree of overlap increases, the relative distance decreases, and the contact margin time increases.

  Further, Patent Document 1 discloses that control is performed so that the braking force decreases as the steering wheel steering angular velocity of the steering handle increases, in other words, as the driver rotates the steering handle faster. It is described that the applied braking force is suppressed and the lane can be changed smoothly.

JP 2005-1500 A ([0019], [0020], [0038])

  By the way, when avoiding contact with an obstacle ahead of the host vehicle, it is considered that steering assist control is also effective in addition to automatic brake control.

  However, Patent Document 1 does not disclose the relationship between automatic brake control and steering assist control.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a vehicle contact avoidance assistance device that enables accurate cooperative control of automatic brake control and steering assist control.

  A vehicle contact avoidance support device according to the present invention is a vehicle contact avoidance support device that performs contact avoidance support of a host vehicle with respect to the obstacle according to a positional relationship between the host vehicle and an obstacle ahead of the host vehicle. Features 1-4.

  1. In a vehicle contact avoidance assistance device that performs contact avoidance support for a host vehicle with respect to the obstacle according to a positional relationship between the host vehicle and an obstacle ahead of the host vehicle, the relative position between the host vehicle and the obstacle ahead of the host vehicle Based on the relative position of the detected obstacle, the automatic brake control means for performing automatic brake control based on the relative position of the detected obstacle, and the detected relative position of the obstacle, Steering assist control means for performing steering assist control of steering of the host vehicle in a direction that avoids contact with the obstacle, and the relative position of the detected obstacle is within a first region in front of the host vehicle. The automatic brake control is performed by the automatic brake control means, and the detected relative position of the obstacle is within the second region wide in the vehicle width direction outside the first region in front of the host vehicle. In the case of And performing the steering assist control by the steering assist control means.

  According to the invention having the feature 1, when the relative position of the obstacle ahead of the host vehicle detected by the relative position detection means is within the first area in front of the host vehicle, the automatic brake control is performed and detected. Since the steering assist control is performed when the relative position of the obstructed obstacle is within the second region wide in the vehicle width direction outside the first region, the obstacle is a vehicle in front of the host vehicle. When the vehicle is present in a narrow region in the width direction, automatic brake control is performed, and steering assist control is performed in the second region where the offset (deviation) in the vehicle width direction between the obstacle and the vehicle is large. Accurate coordinated control of automatic brake control and steering assist control is performed.

  2. In the invention having the above feature 1, when the relative position of the detected obstacle is within the first region in front of the host vehicle, the automatic brake control means performs the automatic brake control and the The steering assist control is performed by a steering assist control means.

  According to the invention having the feature 2, when the obstacle exists in a narrow area in the vehicle width direction in front of the host vehicle, the automatic brake control is performed and the steering assist control is performed. Since the steering assist control is performed in the second region in which the offset in the vehicle width direction increases, more accurate cooperative control of the automatic brake control and the steering assist control is performed.

  3. In the invention having the above feature 1 or 2, the first region in front of the host vehicle is characterized in that the length in the vehicle width direction is set to be equal to the vehicle width of the host vehicle.

  With this setting, more accurate cooperative control of automatic brake control and steering assist control is performed.

  4). In the invention having any one of the above characteristics, the first region or the second region in front of the host vehicle changes a length in the vehicle width direction according to a relative vehicle speed of the host vehicle with respect to the obstacle. It is characterized by that.

  By controlling in this way, it is possible to perform coordinated control of accurate automatic brake control and steering assist control according to the relative vehicle speed.

  According to the present invention, when the relative position of the obstacle in front of the host vehicle is within the first region in front of the host vehicle, automatic brake control is performed, and the relative position is a vehicle width outside the first region. When the vehicle is in the second region that is wide in the direction, the steering assist control is performed, so that accurate cooperative control of the automatic brake control and the steering assist control can be performed.

  For example, if the driver who drives the vehicle operates the steering handle to avoid the obstacle in the second region where the offset (deviation) in the vehicle width direction between the obstacle and the vehicle increases, In addition, since the steering assist control is performed to reduce the amount of steering wheel operation by the driver, a margin can be given to the operation of the steering wheel by the driver.

  On the other hand, since the offset (deviation) in the vehicle width direction between the obstacle and the own vehicle is small, for example, when they overlap, automatic brake control is performed. Can do.

1 is a schematic block configuration diagram of a vehicle in which a vehicle contact avoidance assistance device according to an embodiment of the present invention is incorporated. It is relative position explanatory drawing, such as a lateral distance detected by a radar. It is explanatory drawing of an automatic brake control area | region and an avoidance steering assist control area | region. It is a flowchart with which description of the 1st Example of the contact avoidance operation | movement of the vehicle incorporating the contact avoidance assistance apparatus for vehicles is built. FIG. 5A is an explanatory diagram of an operation effective region in the automatic brake control region and the steering assist control region, and FIG. 5B is an explanatory diagram of an operation effective region in the steering assist control region. It is a flowchart used for description of 2nd Example of the contact avoidance operation | movement of the vehicle incorporating the contact avoidance assistance apparatus for vehicles. It is explanatory drawing with which description of 2nd Example of the contact avoidance operation | movement of the vehicle incorporating the contact avoidance assistance apparatus for vehicles is provided. It is explanatory drawing of the modification of an automatic brake control area | region and a steering assist control area | region.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic block diagram of a vehicle 10 (also referred to as a host vehicle) in which a vehicle contact avoidance assistance device according to an embodiment of the present invention is incorporated.

  The vehicle 10 includes a contact avoidance ECU 20 (contact avoidance support means) that is an electronic control unit (ECU) having various function parts (various function means) realized by a CPU executing a program stored in a memory. Steering assist control and automatic brake control are executed by a steering assist control unit 90 (steering assist control unit) and an automatic brake control unit 92 (automatic brake control unit), which are functional units of the contact avoidance ECU 20, respectively.

  The vehicle 10 has four wheels 22 {front wheel right wheel (FRW) 22R, front wheel left wheel (FLW) 22L}, wheel 24 {rear wheel right wheel (RRW) 24R, rear wheel left wheel (RLW) 24L}, Wheel speed sensors 61 to 64 are respectively attached to the four wheels 22 and 24, and each wheel speed Vw is taken into the contact avoidance ECU 20 from the wheel speed sensors 61 to 64. The contact avoidance ECU 20 constantly updates the average value of these four wheel speeds Vw as the vehicle speed Vs that is the speed of the vehicle 10.

  The four wheels 22 and 24 are provided with brake actuators 51 to 54 each constituted by a disc brake or the like that generates a braking force. Each braking force (braking hydraulic pressure) of the brake actuators 51 to 54 is independently controlled by four pressure regulators (not shown) in the hydraulic control device 44.

  The hydraulic control device 44 generates a braking hydraulic pressure corresponding to the depression amount θb of the brake pedal 40 detected by the depression amount sensor 42 and applies to the brake pedal 40 output from the automatic brake control unit 92 configuring the contact avoidance ECU 20. The above four pressure regulators (not shown) generate braking hydraulic pressures according to braking force command values Fb that are not dependent (so-called braking force command values by the brake-by-wire), and output the braking hydraulic pressures to the brake actuators 51 to 54, respectively. ing.

  When the depression amount θb is input from the depression amount sensor 42 and the braking force command value Fb is input from the automatic brake control unit 92 based on the depression operation of the brake pedal 40 by the driver, the hydraulic control device 44 The brake hydraulic pressure is generated in accordance with whichever is greater.

  Therefore, when the vehicle 10 turns {including, for example, any case where the vehicle 10 slips and steers, or is steered (steered) by operating the steering handle 70. }, If the braking hydraulic pressure transmitted to the brake actuators 51 to 54 is independently controlled by the braking force command value Fb, a difference is generated between the braking forces of the left and right wheels 22L, 24L, 22R, 24R, and the yaw moment of the vehicle 10 is increased. Can be controlled arbitrarily and accurately, avoiding the occurrence of understeering at the time of turning, and avoiding oversteering and spins, thereby stabilizing the behavior of the vehicle. Also, when braking (automatic braking when the brake pedal 40 is not depressed or when the brake pedal 40 is depressed), if the brake hydraulic pressure transmitted to each brake actuator 51 to 54 is controlled independently, the wheels 22 and 24 are controlled. Anti-lock brake control can be performed to suppress the lock.

  On the other hand, in this embodiment, the driving force is transmitted from the engine 34 to the front wheels 22 (22R, 22L) through the transmission (T / M) 36 among the four wheels 22, 24. The rear wheels 24 (24R, 24L) function as driven wheels that rotate as the vehicle 10 travels.

  The engine 34 has its rotational speed (engine rotational speed) controlled through a throttle actuator 32 that adjusts the throttle opening of a throttle valve 33 provided in the engine 34.

  The throttle opening of the throttle valve 33 is adjusted through the engine ECU 30 and the throttle actuator 32 according to the operation angle (accelerator angle, operation amount) θa of the accelerator pedal 26 detected by the operation amount sensor 28.

  The steering device 88 of the vehicle 10 basically includes a steering handle 70 (steering wheel) that is rotated (steered) by a driver, a steering angle sensor 72 that detects a steering angle θs of the steering handle 70, A steering actuator 76 constituting the power steering device and a steering mechanism 74 having a rack and pinion mechanism for steering the front wheels 22 (front and left and right wheels) are configured.

  In this case, the steering device 88 transmits the rotation of the steering handle 70 by the driver to the pinion constituting the steering mechanism 74 through the steering shaft and the connecting shaft, and the rack reciprocates due to the rotation of the pinion. Is transmitted to the front wheels 22 through the tie rods, so that the vehicle 10 is steered.

  When the steering of the vehicle 10 is executed, the steering angle θs accompanying the rotation of the steering handle 70 by the driver is input to the steering actuator 76, so that the driving force of the steering actuator 76, that is, the steering handle. A steering assist force depending on the operation of 70 is transmitted to the front wheels 22 through the rack of the steering mechanism 74.

  On the other hand, the steering assist command value Fs output from the steering assist control unit 90 constituting the contact avoidance ECU 20 (here, the steering assist command value by the steer-by-wire, also referred to as the avoidance steering assist command value Fs) is the steering actuator 76. , The steering assist torque (steering torque, also referred to as avoidance steering assist torque) corresponding to the steering assist command value Fs is output to the steering mechanism 74. Note that the steering assist is not limited to the processing by steer-by-wire, but may be processing for changing the gear ratio of the steering mechanism 74 or processing for changing the assist value of the EPS device.

  In addition, when the avoidance steering assist force is generated, when the steering assist command value Fs is output to the steering actuator 76, the braking force command value Fb that does not depend on the brake pedal 40 from the automatic brake control unit 92 is hydraulically combined or independently. The braking hydraulic pressure output to the control device 44 and transmitted to the brake actuators 51 to 54 is independently controlled, and a difference in braking force between the left and right wheels 22L, 24L, 22R, 24R is generated to generate a yaw moment in the vehicle 10. Thus, the avoidance steering assist force may be generated.

  The steering mechanism 74 outputs a steering assist force corresponding to the steering assist torque corresponding to the steering assist command value Fs to the front wheels 22, so that the front wheels 22 steer the front wheels 22 by a steering amount corresponding to the steering assist force. Can be made. As will be described later, this steering assist command value Fs is basically avoided by the rotation operation of the steering handle 70 by the driver when trying to avoid contact with an obstacle ahead of the vehicle 10. When it is determined that the steering is not sufficient, it is generated to assist this.

  Further, the vehicle 10 is provided with a radar 80 in a front grill portion or the like. The radar 80 transmits an electromagnetic wave such as a millimeter wave toward the front of the vehicle 10 as a transmission wave, detects the size of an obstacle (for example, a preceding vehicle, etc.) based on the reflected wave, and the obstacle vehicle. The direction from 10 (own vehicle) is detected, and at the same time, the relative distance L between the obstacle and the own vehicle (inter-vehicle distance if the obstacle is a vehicle), the relative speed Vr between the obstacle and the own vehicle. It operates as a relative position detecting means for detecting the like. Note that a laser radar, a stereo camera, or the like can be employed instead of the millimeter wave radar as a relative position detecting means for detecting a relative position with respect to an obstacle.

  The contents such as the relative position detected by the radar 80 will be described with reference to FIG. In this embodiment, the obstacle is a vehicle 12 (another vehicle or a preceding vehicle) traveling in front of the vehicle 10 (own vehicle) traveling on the road 200 in the direction of the arrow. The present invention can also be applied to obstacles that are present.

  As is well known, the radar 80 first detects the relative distance L from the vehicle 10 (the own vehicle, which is depicted in two places at different positions in FIG. 2) to the vehicle 12 ahead. Can do. Further, the vehicle width Wo of the vehicle 12 ahead can be detected. The vehicle width Wm of the host vehicle 10 is stored in advance in a memory (storage unit) in the contact avoidance ECU 20 and the radar 80. Next, the relative speed Vr of the vehicle 10 with respect to the vehicle 12 can be detected. Further, a contact margin time TTC as a contact margin value can be calculated as TTC = L / Vr from the detected relative distance L from the vehicle 10 to the preceding vehicle 12 and the relative speed Vr.

In this case, the contact avoidance ECU 20 determines, for example, from the vehicle width Wm of the vehicle 10 (own vehicle) itself, the vehicle width Wo of the vehicle 12 ahead detected by the radar 80, and a predetermined margin width (margin lateral distance) α. The target lateral avoidance distance Dt required when the vehicle 10 (the host vehicle) avoids contact with the preceding vehicle 12 and passes is calculated by the following equation (1).
Dt = (Wo / 2) + α + (Wm / 2) (1)

  The lateral avoidance distance (referred to as lateral distance, deviation, deviation amount, offset, or offset amount) D increases because the vehicle 10 (own vehicle) avoids contact with the preceding vehicle 12 and overtakes it. This is a case where the other vehicle center axis 12c of the front vehicle 12 overlaps the center axis 10c, that is, a case where the front vehicle 12 exists in front of the vehicle 10 (own vehicle).

  Even when the vehicle 12 ahead is present in front of the vehicle 10 (own vehicle), when the vehicle 10 catches up with another vehicle 12 traveling on the same route on the road 200, the vehicle 10 If the vehicle 10 moves in the vehicle width direction (lateral direction) by the above-mentioned target lateral avoidance distance Dt when passing the side of the vehicle 12 ahead of the vehicle by changing the course and exiting ahead of the vehicle 12, It is possible to pass through the side of the vehicle 12 ahead, leaving a lateral distance corresponding to the margin width α. In addition, the distance (deviation) in the vehicle width direction between the own vehicle center axis 10c and the other vehicle center axis 12c of the vehicle 12 ahead is referred to as an offset D as described above.

  In FIG. 1 again, the vehicle 10 is provided with a lateral G sensor 84 that detects lateral G (lateral acceleration) generated in the vehicle 10 and a yaw rate sensor 82 that detects the yaw rate Yr generated in the vehicle 10. It has been.

  The vehicle 10 incorporating the vehicle contact avoidance assistance device according to the embodiment of the present invention is basically configured as described above. Next, the operation thereof will be described.

  Here, first, an example of an operation condition of automatic brake control by the automatic brake control unit 92 and an example of an operation condition of contact avoidance steering assist control (avoidance steering assist control) by the steering assist control unit 90 will be qualitatively described.

  The operating condition of the automatic brake control by the automatic brake control unit 92 is basically determined based on a contact margin time TTC (TTC = L / Vr) as a contact margin value for an obstacle ahead of the vehicle 10. The determination may be made based on the relative distance L to an obstacle ahead of the vehicle 10 (including the preceding vehicle).

  The contact margin value is a parameter for determining the possibility of contact between an obstacle (here, the vehicle 12) in front of the host vehicle (vehicle 10) and the host vehicle. On the contrary, the smaller the contact margin value, the higher the possibility of contact. The contact margin value includes the contact margin time TTC and the relative distance L to the obstacle.

  The smaller the contact allowance time TTC is, the higher the possibility of contact with an obstacle is. Therefore, when the contact allowance time TTC is smaller than a predetermined threshold value, automatic brake control and / or operation is performed to avoid contact. When the direction handle 70 is operated, the avoidance steering assist control is activated.

  In this case, the automatic brake control unit 92 calculates a braking force command value Fb for applying an appropriate braking force to the brake actuators 51 to 54 and outputs the braking force command value Fb to the hydraulic control device 44 in order to generate a necessary deceleration. As a result, a braking hydraulic pressure corresponding to the braking force command value Fb is generated by the hydraulic control device 44, and the braking force is applied to the wheels 22 and 24 through the brake actuators 51 to 54 by the generated braking hydraulic pressure.

  When the automatic brake control unit 92 determines that the accelerator pedal 26 is not depressed from the operation amount θa of the accelerator pedal 26, the automatic brake control unit 92 simultaneously controls the throttle actuator 32 to operate the throttle valve 33 in the closing direction by a predetermined amount ( Throttle-by-wire) (see the dotted arrow line from the contact avoidance ECU 20 toward the throttle actuator 32 in FIG. 1).

In this embodiment, as shown in FIG. 3 (see also FIG. 2), the automatic brake control region Bca (the first region in the vehicle width direction in front of the host vehicle) has a length in the vehicle width direction in front of the vehicle 10. Is set. For example, it is set to an area equivalent to the vehicle width Wm of the vehicle 10 (own vehicle) (Bca≈Wm). The radar 80 detects whether or not the other vehicle center axis 12c of the vehicle 12 in front of the vehicle 10 is in the automatic brake control region Bca, and if so, the automatic brake control flag fb is turned on (fb → ON) state. In other words, as shown in FIG. 2, the offset D between the other vehicle central axis 12c of the vehicle 12 ahead and the own vehicle central axis 10c is equal to or less than half the vehicle width Wm {D ≦ (Wm / 2)}. Sometimes the automatic brake control flag fb is turned on (fb → ON).

  In FIG. 2, the automatic brake control flag fb of the vehicle 10 drawn on the lower side is turned on, and the automatic brake control flag fb of the vehicle 10 drawn on the upper side is turned off.

  In this embodiment, when the automatic brake control flag fb is in the ON state (fb = ON), the automatic brake control unit 92 is a case where the contact margin time TTC is smaller than the threshold value and the steering is performed. When the operation of the handle 70 is not detected, for example, the time change value of the steering angle θs output from the steering angle sensor 72, that is, the steering angular velocity dθs / dt (time differential value) is dθs / dt≈0, When the steering handle 70 is at the midpoint position, the automatic brake control is actually activated. At this time, the automatic brake control unit 92 generates a braking force command value Fb (Fb> 0).

  On the other hand, the operating condition of the avoidance steering assist control by the steering assist control unit 90 is basically the midpoint obtained from the steering angle sensor 72 (the vehicle 10 travels linearly for a predetermined time in addition to the above-described contact margin time TTC. The steering angle θs from the steering angle θ), the steering angular velocity dθs / dt obtained by time differentiation of the steering angle θs, the lateral G detected by the lateral G sensor 84, and the yaw rate sensor 82. The determination is made in consideration of the yaw rate (actual yaw rate) Yr.

  SE = SE (θs, dθs / dt, lateral), which is a predetermined function, with the steering angle θs, steering angular velocity dθs / dt, lateral G, yaw rate Yr, and the like as variables. G, Yr) is digitized (assuming that the larger the SE is, the greater the avoidance steering operation is determined by the driver), and this value requires the avoidance steering assist operation. When it is determined that the value (threshold value) or a value lower than the value (threshold value), avoidance steering assist control is activated.

  In this case, the reference yaw rate Ys calculated according to the steering angle θs and the vehicle speed Vs is changed to the assist yaw rate Ya.

  When calculating the assist yaw rate Ya, the difference between the above-described target lateral avoidance distance Dt and the lateral distance D (the amount of deviation between the vehicle center axis 10c and the other vehicle center axis 12c) is multiplied by a predetermined gain to assist. Calculate the lateral acceleration. Further, the assist yaw rate Ya is calculated by dividing the assist lateral acceleration by the vehicle speed Vs.

  The steering assist control unit 90 outputs a steering assist command value Fs for generating the calculated assist yaw rate Ya to the steering actuator 76.

  Accordingly, a steering assist torque corresponding to the steering assist command value Fs is applied from the steering actuator 76 to the steering mechanism 74, whereby the turning behavior of the vehicle 10 is controlled and assisted by the assist yaw rate Ya.

  In this embodiment, as shown in FIG. 3, the steering assist control area Sca is wider in the vehicle width direction (width direction of the road 200) than the automatic brake control area Bca (first area ahead of the host vehicle) described above. It is set within (in the second area ahead of the host vehicle). That is, the steering assist control area Sca is executed in the automatic brake control area Bca and also in the outer area Sca1 (Sca = Bca + 2 × Sca1). The steering assist control area Sca1 is, for example, a half value (Sca1≈Wm / 2) of the automatic brake control area Bca (≈Wm).

  A road center line 202 and a road left end line 204 are displayed on the road 200 in FIG.

  Whether the vehicle 12 in front of the vehicle 10 is in the steering assist control region Sca is detected by the radar 80, and if it is, the steering assist flag fs (this flag generates the steering assist command value Fs). Flag) is turned on (fs → ON).

  When the steering assist flag fs is in the on state, the driver's avoidance steering operation state determination value SE is determined, and the value of the avoidance steering operation state determination value SE is a value that requires avoidance steering assist control. Alternatively, when it is determined that the value is lower than this, the avoidance steering assist control is activated and the steering assist command value Fs is generated (Fs> 0).

  Even when the steering assist flag fs is on, the steering assist command value Fs is determined when it is determined from the avoidance steering operation state determination value SE that the steering assist operation is not necessary. Not generated (Fs = 0).

  The reason why the offset D of the steering assist control area Sca is expanded to the area {D> (Wm / 2)} that exceeds half of the vehicle width Wm of the vehicle 10 is that the avoidance steering assist operation is not fully automatic and driving. Since the operation of the steering handle 70 of the driver, that is, the so-called steering operation is assumed, it is difficult for the driver to operate excessively. Even if the driver operates excessively, the driver feels uncomfortable because the driver's steering operation is assisted. It is because it does not give.

[First embodiment]
Next, the operation of the first example based on the offset (lateral distance) D by the contact avoidance ECU 20 of the vehicle 10 equipped with the contact avoidance support device according to this embodiment will be described with reference to the flowchart of FIG.

  In step S1, the vehicle 10 that is traveling on the road 200 uses the radar 80 to determine the relative position (relative distance L, vehicle width Wo, relative speed Vr, contact margin time TTC, vehicle 12 in front of the vehicle 10 (own vehicle). Detect offset D). At this time, the contact avoidance ECU 20 calculates the target lateral avoidance distance Dt {Dt = (Wo / 2) + α + (Wm / 2)}. The relative position detection process is always performed by timer interruption in the ms order.

In step S2, the preceding is based on the value of the offset (lateral distance) D and the value Wm / 2 that is half the vehicle width Wm of the vehicle 10 (or the value Wo / 2 that is half the vehicle width Wo of the vehicle 12). It is determined whether or not the vehicle 12 to be operated is located in {D ≦ Wm / 2} within the automatic brake control region Bca (automatic brake control region). If not, the vehicle 12 is within the steering assist control region Sca1 in step S3. It is determined whether or not the vehicle is located at (Wm / 2 ≦ D ≦ Wm ), and if it is outside the steering assist control region Sca1 (D > Wm ), the automatic brake control flag fb and the steering assist flag fs are set in step S4. Both are turned off (fb → OFF, fs → OFF), and the automatic brake control operation and the avoidance steering assist control are not executed.

  On the other hand, when the vehicle 12 positioned in front of the vehicle 10 (own vehicle) is located in the automatic brake control region Bca in step S2, the automatic brake control flag fb and the steering assist flag fs are determined in step S5. Are turned on (fb → ON, fs → ON), and the automatic brake control operation and the steering assist control are executed according to the contact margin time TTC and the avoidance steering operation state determination value SE described above.

  If the vehicle 12 is located outside the automatic brake control region Bca in the determination in step S2, but it is determined in step S3 that the vehicle 12 is located in the steering assist control region Sca, the automatic brake control is performed in step S5. Both the flag fb and the steering assist flag fs are turned on (fb → ON, fs → ON), and the steering assist control (control of the left and right wheels 22L, 24L, 22R, 24R described above) is performed according to the avoidance steering operation state determination value SE. Including generation of avoidance steering assist force by automatic brake control that generates a yaw moment in the vehicle 10 by generating a difference in power).

  As described above, according to the first embodiment described above, as shown in FIG. 5A, the relative position of an obstacle such as the vehicle 12 in front of the host vehicle 10 detected by the radar 80 as the relative position detecting means is When the vehicle is located in the automatic brake control region Bca that is in the first region in front of the host vehicle, in other words, the offset D that is the lateral movement range of the host vehicle central axis 10c with respect to the obstacle 12o of the vehicle 10 is If it is within the range of ± (Wm / 2) (left direction is “−” and right direction is “+”) with respect to the axis 12co, {D <± (Wm / 2)}, automatic brake control flag Both fb and the steering assist flag fs are turned on (fb = ON, fs = ON) to perform automatic brake control and avoidance steering assist control, or the automatic brake control flag fb is turned on and the steering assist flag fs is turned off. (Fb = ON, fs = OFF) only the automatic brake control is performed.

On the other hand, as shown in FIG. 5B, the relative position of the obstacle 12o in front of the host vehicle 10 detected by the radar 80 is located in the second region wide in the vehicle width direction outside the first region in front of the host vehicle. In this case, specifically, the offset D, which is the lateral movement range of the vehicle center axis 10c, is between − (Wm / 2) and − ( Wm ) with respect to the obstacle center axis 12co, or (Wm / 2). If it is between ( Wm ), the automatic brake control flag fb and the steering assist control flag fs are turned on (fb = ON, fs = ON), and the steering assist control (as described above for the steering assist control). In addition, avoidance steering assist control by automatic brake control that generates a yaw moment in the vehicle 10 by generating a difference between the left and right braking forces is also performed.

[Second Embodiment]
Next, regarding the operation of the second example in consideration of the contact allowance time TTC (or the inter-vehicle distance L) in addition to the offset (lateral distance) D by the contact avoidance assist ECU in which the contact avoidance assist device according to this embodiment is mounted. This will be described with reference to the flowchart of FIG. 6 and the operation explanatory diagram of FIG.

  In the flowchart of FIG. 6, the processing from step S1 to S5 is the same as the processing shown in the flowchart of FIG.

  Based on the offset (lateral distance) D, the automatic brake flag fb and the steering assist flag fs (both may be considered as flags related to the vehicle width direction) are both turned on. In S6, it is determined whether or not the contact margin time TTC detected in step S1 is equal to or shorter than a predetermined time T1 (TTC ≦ T1).

  If the time exceeds the predetermined time T1 (in FIG. 7, a time before time t1), it is determined that it is not necessary to avoid contact, and in step S7, the automatic brake flag fb and the steering assist flag fs {the distance between the vehicles ( It can be considered as a flag related to the (axle) direction. } Are turned off.

  If the time is within the predetermined time T1 (time point after time t1), in step S8, the ON state of the automatic brake flag fb and the steering assist flag fs is confirmed {both the flags related to the inter-vehicle (axle) direction are turned on. May be considered}, a contact avoidance standby state is set (after time t1). As a result, the automatic brake control and the avoidance steering assist control are set in a standby state (time points t1 to t3).

  Between time t0 and time t1 in FIG. 7, the contact margin time TTC of the vehicle 10 with respect to the vehicle 12 is longer than the predetermined time T1, and the avoidance steering operation state determination value SE is also greater than the threshold value. Neither is executed.

  Between time points t1 and t2, the vehicle is in a standby state (fb → ON, fs → ON), and automatic brake control is executed when the contact margin time TTC of the vehicle 10 with respect to the vehicle 12 becomes smaller than the threshold value Tth1. However, since the acceleration of the steering angle θs has a substantially zero value and is smaller than the threshold value, the avoidance steering assist control is not executed (see time t1b in FIG. 7).

  Further, when the avoidance steering operation state determination value SE becomes smaller than the threshold value between the time points t2 and t3 when the steering handle 70 of the vehicle 10 is operated, the avoidance steering assist control (the left and right wheels 22L described above) is performed. , 24L, 22R, and 24R are also generated (including generation of avoidance steering assist force by automatic brake control that generates a yaw moment in the vehicle 10) (see, for example, time t2b in FIG. 7). ).

  As described above, according to the first and second embodiments described above, the avoidance steering assist control (steer assist control) for assisting the driver's operation of the steering handle 70, that is, the so-called steering operation, and the obstacle If the vehicle has an automatic brake control that automatically brakes according to the distance from the vehicle 12 (the preceding vehicle), etc., and the offset D between the vehicle 12 and the vehicle 10 (own vehicle) is relatively large, When only the avoidance steering assist control is performed and the offset D is relatively small, only the automatic brake control or the automatic brake control is performed in addition to the avoidance steering assist control.

  Therefore, the contact avoidance steering by the driver's steering handle 70 is performed even when the offset D with respect to the vehicle 12 ahead is relatively large, and even in such a case, avoidance steering assist control is reliably executed. . Further, since the automatic brake control is executed only when the offset D that actually requires automatic braking is relatively small and is not executed when the offset D is relatively large, the avoidance steering assist control and the automatic brake control are not performed. Accurate cooperative processing can be performed.

  The present invention is not limited to the above-described embodiment. For example, as shown in FIG. 8, in the automatic brake control region Bca and the steering assist control region Sca set in front of the host vehicle, the relative vehicle speed Vr is the threshold vehicle speed Vrth. If the vehicle speed exceeds the automatic vehicle speed control range Bca ′ and the avoidance steering assist control region Sca ′, which are narrow control regions (unit: [m]) according to the increase in the relative vehicle speed Vr, It goes without saying that various configurations can be adopted based on the description in this specification.

DESCRIPTION OF SYMBOLS 10 ... Vehicle 22, 24 ... Wheel 20 ... Contact avoidance ECU 80 ... Radar 90 ... Steering assist control part 92 ... Automatic brake control part

Claims (4)

In the vehicle contact avoidance support device that performs contact avoidance support of the host vehicle with respect to the obstacle according to the positional relationship between the host vehicle and the obstacle ahead of the host vehicle,
Relative position detecting means for detecting the position of the obstacle center axis with respect to the host vehicle center axis ;
Automatic brake control means for performing automatic brake control based on the position of the obstacle center axis with respect to the detected vehicle center axis ;
Steering assist control means for performing steering assist control in a direction to avoid contact with the obstacle based on the detected position of the obstacle center axis with respect to the own vehicle center axis ;
Position before Symbol obstacle central axis, wherein when in the vehicle center axis within the first region of the vehicle front consisting of the left and right uniform region in the vehicle width direction with respect to line the automatic brake control by the automatic brake control means wherein by the steering assist control means performs the steering assist control, when the position of said detected obstacle central axis, in said second region of either a respective uniform region of the outer side of the first region performs In the vehicle contact avoidance assisting device, the steering assist control is performed by the steering assist control means. In the vehicle contact avoidance assistance device according to claim 1,
Wherein the first region of the front of the vehicle is set equal to the vehicle width of the vehicle, before Symbol realm plus both second region outside of the first region in the first region, the vehicle of the vehicle vehicular contact avoidance support device characterized in that it is set to 2 times the width. In the vehicle contact avoidance assistance device according to claim 1 or 2,
The steering assist control includes a avoidance steering assist control by an automatic brake control that generates a yaw moment in the host vehicle by generating a difference in the left and right braking force of the host vehicle. In the vehicle contact avoidance assistance device according to claim 1 ,
Said first region or said second region ahead of the vehicle, when the relative speed with respect to the obstacle of the vehicle is above a threshold vehicle speed, depending on the amount exceeds said first and second regions of pre-Symbol vehicle width direction The vehicle contact avoidance assisting device characterized in that each is changed to a narrow area.

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