JP2012196997A - Vehicle drive support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a driver smoothly perform a collision avoiding operation by releasing an automatic brake when the driver has performed the collision avoiding operation even during the automatic brake is operated, in a precrash control system.SOLUTION: A collision predicting time TTC of an own vehicle 1 with respect to a front obstacle and a preset brake assist determination time To are compared (S4), and when TTC≤To, it is checked whether an acceleration pedal is pedalled in (S6). Then, when the acceleration pedal is not pedalled in, automatic brake control is executed, and the own vehicle 1 is forcibly decelerated in speed (S8). Alternatively, when it is detected that the acceleration pedal is pedalled in, it is determined that the driver performs the collision avoiding operation, and the automatic brake is released (S9).

Description

  The present invention relates to a vehicle driving support device that releases an automatic brake when a collision avoidance operation of a driver is detected even when the automatic brake is activated.

  As is well known, the pre-crash control system recognizes an obstacle including a vehicle approaching the host vehicle based on environmental information in front of the host vehicle detected by an in-vehicle camera, a radar device, etc. Investigate whether or not a collision is unavoidable to the host vehicle from the speed / course, and issue a warning to the driver. If it is determined that a collision is unavoidable, the information is transmitted to a brake control device, etc. Is forcibly decelerated.

  Further, in the pre-crash control system, when the automatic brake is in operation, as disclosed in, for example, Patent Document 1 (Patent No. 3106631), the throttle valve is fully closed to operate the engine brake. A technique for improving the braking force is known.

Japanese Patent No. 3106631

  In the technique disclosed in the above-mentioned document, since the throttle valve is fully closed when the automatic brake is operating, even when the driver steps on the accelerator pedal, the inter-vehicle distance from the preceding vehicle is small. Until secured, the throttle valve will not open.

  However, even when the automatic brake is in operation, for example, when the driver determines that collision can be avoided, it may be preferable to cancel the automatic brake control and open the throttle valve in conjunction with the accelerator pedal. is there. Even in such a situation, since the throttle priority control is executed in the technique disclosed in the above-described document, the throttle valve opens even if the accelerator pedal is depressed until the inter-vehicle distance is secured. There is an inconvenience that makes the driver feel uncomfortable.

  In view of the above circumstances, the present invention enables the driver to release the automatic brake and smoothly perform the collision avoidance operation when the driver performs the collision avoidance operation even when the automatic brake is operating. An object of the present invention is to provide a vehicle driving support device that can reduce the uncomfortable feeling given to the vehicle.

  The present invention detects a front obstacle based on a traveling environment detection means mounted on a vehicle and detecting a traveling environment ahead of the traveling direction of the vehicle, and a traveling environment ahead of the host vehicle detected by the traveling environment detection means. A collision prediction time calculation means for obtaining a collision prediction time based on a distance and relative vehicle speed between the front obstacle and the vehicle, and the collision prediction time obtained by the collision prediction time calculation means is less than a brake assist determination time. In this case, in the vehicular driving support device including the automatic brake control unit that operates the automatic brake, the automatic brake control unit releases the automatic brake when the collision avoidance operation of the driver is detected.

  According to the present invention, even when the automatic brake control means is operating the automatic brake, when the driver's collision avoidance operation is detected, the automatic brake is released. The collision avoidance operation can be performed smoothly, and the uncomfortable feeling given to the driver can be reduced.

Schematic configuration diagram of a vehicle equipped with a vehicle driving support device Configuration diagram of vehicle driving support device Flow chart showing pre-crash control routine Flow chart showing automatic brake control subroutine The relationship between the right turn vehicle and the own vehicle at the intersection is shown, (a) is an explanatory diagram showing a state in which the predicted collision time between the own vehicle and the right turn vehicle is within the brake assist determination time, and (b) is a state in which a collision can be avoided. Explanatory drawing showing The relationship between the oncoming vehicle and the host vehicle on a narrow road is shown, (a) is an explanatory diagram showing a state where the predicted collision time between the host vehicle and the right turn vehicle is within the brake assist determination time, and (b) is a collision avoidance Explanatory diagram showing the state Explanatory diagram showing the relationship between the oncoming vehicle and the host vehicle at the level crossing

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 in FIG. 1 denotes a vehicle, and the vehicle 1 is provided with an in-vehicle camera 32 as a traveling environment detection means. The in-vehicle camera 32 is a stereo camera having a main camera 32a and a sub camera 32b, and an image of the traveling environment ahead of the traveling direction imaged by both the cameras 32a and 32b is imaged in a predetermined image by an image processing unit (IPU) 33. Processed and output.

  On the other hand, reference numeral 3 denotes a vehicle driving support device. As shown in FIG. 2, a pre-crash control unit 21, an engine control unit (hereinafter referred to as “E / G_ECU”) 22, a brake control unit (hereinafter referred to as “BK_ECU”). Each control unit is connected through an in-vehicle communication line 24 such as a CAN (Controller Area Network). Each unit 21 to 23 is configured by a microcomputer including a CPU, a ROM, a RAM, and the like, and a control program for realizing an operation set for each system is stored in the ROM.

  Further, on the input side of the pre-crash control unit 21, there are an IPU 33, a vehicle speed sensor 36 for detecting the vehicle speed S [Km / h], an accelerator opening sensor 37 for detecting the accelerator pedal depression amount AP [%], and the like. Various sensors are connected. Furthermore, alarm means 41 such as a buzzer, a warning lamp, and a speaker are connected to the output side of the pre-crash control unit 21.

  On the other hand, a throttle actuator 42 provided in the electronic control throttle 31 is connected to the output side of the E / G_ECU 22, and a brake actuator 43 for operating the brake is connected to the output side of the BK_ECU 23.

  As shown in FIG. 1, the electronic control throttle 31 is provided on the intake passage side of the engine 30. The throttle valve 31 a of the electronic control throttle 31 is opened and closed by a throttle actuator 42, and the operation of the throttle actuator 42 is performed. It is controlled by the E / G_ECU 22. Therefore, when the E / G_ECU 22 controls the operation of the throttle actuator 42, the opening degree of the throttle valve 31a is adjusted, and a desired engine output is obtained.

  The brake actuator 43 adjusts the brake hydraulic pressure supplied to the brake wheel cylinder 43a provided on each wheel. When the brake actuator 43 is driven by a drive signal from the BK_ECU 23, the brake wheel cylinder 43a. As a result, a braking force is generated on each wheel and the vehicle is forcibly decelerated.

  On the other hand, the pre-crash control unit 21 shown in FIG. 2 monitors an obstacle (a front obstacle) that exists in front of the vehicle traveling direction imaged by the in-vehicle camera 32 based on the image signal from the IPU 33. When a front obstacle is detected, the collision prediction time TTC is obtained based on the image captured by the in-vehicle camera 32, and the collision prediction time TTC is compared with a preset brake assist determination time To to determine the vehicle 1 Determine the possibility of collision with a forward obstacle. When it is determined that the possibility of a collision is high (TTC ≦ To), an alarm is issued from the alarm means 41 and automatic brake control is executed. At that time, if the driver detects the depression of the accelerator pedal, the automatic brake control is canceled.

  Specifically, the pre-crash control executed by the above-described pre-crash control unit 21 is processed according to the pre-crash control routine shown in FIG.

  This routine is executed every predetermined calculation cycle after the ignition switch is turned on. First, in step S1, image data in front of the host vehicle imaged by the in-vehicle camera 32, vehicle speed S detected by the vehicle speed sensor 36, accelerator opening degree. Parameters necessary for pre-crash control such as the accelerator pedal depression amount AP detected by the sensor 37 are read.

  Subsequently, in step S2, there is a front obstacle (stopped or traveling preceding vehicle, oncoming vehicle, pedestrian crossing the road, etc.) in the traveling direction of the vehicle based on the image data ahead of the vehicle captured by the in-vehicle camera 32. Investigate whether or not to do so. If a forward obstacle is detected, the process proceeds to step S3. If not detected, the routine is directly exited.

  In step S3, based on the parallax of both cameras 32a and 32b, the distance L between the front obstacle imaged by both cameras 32a and 32b and the host vehicle 1 is calculated, and this distance L is calculated from the front obstacle and the host vehicle. 1 is divided by the relative vehicle speed ΔS with respect to 1 to calculate a predicted collision time TTC (TTC ← L / ΔS). The processing in steps S2 and S3 corresponds to the collision prediction time calculation means of the present invention.

  Thereafter, the process proceeds to step S4, and the collision prediction time TTC is compared with a preset brake assist determination time To. The brake assist determination time To is a predicted time when it is determined that a collision with a front obstacle cannot be avoided, and is set to about 1.0 to 0.5 [sec}, for example.

  If the predicted collision time TTC is less than the brake assist determination time To (TTC ≦ To), the driver's braking operation is not performed or the braking force operated by the driver is weak. Is determined to be close to the front obstacle, and the process proceeds to step S5. When it is determined that TTC> To, it is determined that the vehicle can be stopped by the driver's brake operation, and the routine is directly exited.

  In step S5, an alarm signal is output to the alarm means 41, and a buzzer sound, lighting / flashing of a warning lamp, sound, etc. to the driver that the vehicle 1 is approaching a front obstacle. To inform. Next, the process proceeds to step S6, and it is checked whether or not the accelerator pedal is depressed based on the accelerator pedal depression amount AP [%] detected by the accelerator opening sensor 37. If depression of the accelerator pedal is not detected, the process proceeds to step S7. If depression of the accelerator pedal is detected, it is determined that the driver is performing a collision avoidance operation, and the process jumps to step S9.

  In step S7, a pre-crash control unit 21 outputs a throttle fully closed signal to the E / G_ECU 22. Then, the E / G_ECU 22 outputs a fully closed signal to the throttle actuator 42 so that the throttle valve 31a is fully closed. As a result, the vehicle is decelerated by the action of the engine brake.

  Next, the process proceeds to step S8, where automatic brake control is executed to assist the braking force and the routine is exited. This automatic brake control is processed in accordance with an automatic brake control subroutine shown in FIG. In this subroutine, first, the relative deceleration is obtained from the difference between the target deceleration set in advance in step S11 and the actual deceleration (actual deceleration) (relative deceleration ← target deceleration−actual deceleration). In step S12, the brake pressure corresponding to the relative deceleration is set, and the routine is exited.

  In the present embodiment, the target deceleration is set to a deceleration close to the maximum deceleration (for example, 0.8 G), but may be variably set according to the vehicle speed or the like. Further, the actual deceleration may be obtained by time differentiation of the vehicle speed S detected by the vehicle speed sensor 36, or may be obtained from the front and rear G detected by the front and rear G sensors in a vehicle equipped with the front and rear G sensors.

  The BK_ECU 23 reads the brake pressure set by the pre-crash control unit 21, outputs a corresponding drive signal to the brake actuator 43, causes the brake wheel cylinder 43a to perform a predetermined braking operation, and matches the actual deceleration to the target deceleration. . At that time, since the throttle valve 31a is in a fully closed state and the engine brake is operating, the load on the brake actuator 43 is reduced by the amount of the engine brake, and the braking operation of the brake wheel cylinder 43a is performed. Sudden deceleration is alleviated.

  On the other hand, when stepping on the accelerator pedal is detected in step S6 described above and it is determined that the driver is performing a collision avoidance operation, and branching to step S9, the automatic brake control is canceled and driving with driver priority is performed. Return to. In the driving with priority on the driver, the throttle valve 31a is basically opened in conjunction with the depression amount of the accelerator pedal, so that the host vehicle 1 can be driven according to the driver's intention.

  Thereafter, in step S10, the output of the warning signal to the warning means 41 is stopped, the warning notification to the driver is stopped, and then the routine is exited. Steps S6 to S9 correspond to the automatic brake control means of the present invention.

  Thus, in this embodiment, in the pre-crash control system, even when the automatic brake is operating, if the driver depresses the accelerator pedal, it is determined that the driver is performing a collision avoidance operation. Since the brake control is released, the driver can smoothly perform the collision avoidance operation without feeling uncomfortable, and can obtain good operability.

  That is, for example, assuming a situation in which a right-turn vehicle (a large trailer in the figure) as a front obstacle crosses the front of the vehicle 1 that goes straight at an intersection A as shown in FIG. When the predicted collision time TTC set based on the distance L to the right-turn vehicle and the relative vehicle speed ΔS falls below the preset brake assist determination time To, an alarm is issued and the automatic brake is activated to decelerate.

  On the other hand, when the driver recognizes that the space where the vehicle 1 can pass is secured on the rear end side after the right turn vehicle crosses, as shown in FIG. The person steps on the accelerator pedal, accelerates the vehicle 1 being decelerated, and tries to pass behind the right-turn vehicle while avoiding a collision by operating the steering wheel. At this time, in the pre-crash control unit 21, when the depression of the driver's accelerator pedal is detected based on the accelerator pedal depression amount AP detected by the accelerator opening sensor 37, the automatic brake is released and the driver's accelerator pedal is released. Since the throttle valve is opened in conjunction with the depression, the driver can pass the host vehicle 1 smoothly.

  Further, in a situation where the host vehicle 1 and the oncoming vehicle face each other on the narrow road B as shown in FIG. 6A, the predicted collision time TTC between the host vehicle 1 and the oncoming vehicle has a preset brake assist. When the determination time To is reached, the automatic brake is activated and decelerates. However, as shown in FIG. 4B, when the host vehicle 1 and the oncoming vehicle approach each other at a low speed, the host vehicle 1 can be passed. When recognizing the space, the driver depresses the accelerator pedal, increases the vehicle speed S, and tries to pass the side of the oncoming vehicle while avoiding a collision by operating the steering wheel. When the driver depresses the accelerator pedal, the pre-crash control unit 21 releases the automatic brake and returns to the driving with priority on the driver, so that good driving operability can be obtained.

  In this case, for example, even if the side of the narrow road B is mud such as a farm field and the driver causes the left wheel of the host vehicle 1 to enter the mud to avoid a collision with the oncoming vehicle, Since the automatic brake is released by depressing the accelerator pedal, the driver can easily escape from the quagmire without stacking the host vehicle 1.

  Similarly, as shown in FIG. 7, when the own vehicle 1 and the oncoming vehicle pass each other in the crossing C, the automatic brake is operated to decelerate the steering wheel so that the driver avoids a collision with the oncoming vehicle. Even when the left wheel is removed when the operation is performed, the automatic brake is released when the driver depresses the accelerator pedal during the collision avoidance operation. Can do.

  The present invention is not limited to the above-described embodiment. For example, the opening acceleration of the throttle valve 31a immediately after the driver depresses the accelerator pedal and the automatic brake is released is limited and the valve is opened slowly. A sudden increase in engine output may be suppressed. In addition to detecting the depression of the accelerator pedal, the collision avoidance operation may be determined by detecting the steering wheel angle and determining that the collision avoiding operation is performed when the steering wheel angle is greater than or equal to the setting.

1 ... vehicle,
3 ... Vehicle driving support device,
21 ... Pre-crash control unit,
23 ... Brake control unit,
31 ... Electronically controlled throttle,
31a ... throttle valve,
32 ... In-vehicle camera,
36 ... Vehicle speed sensor
37 ... accelerator opening sensor,
42 ... Throttle actuator,
43 ... Brake actuator,
AP ... accelerator pedal depression amount,
S ... Vehicle speed,
ΔS: relative vehicle speed,
To ... Brake assist determination time TTC ... Collision prediction time,

Claims (3)

A traveling environment detection means mounted on the vehicle for detecting a traveling environment ahead of the traveling direction of the vehicle;
Collision prediction time calculation means for detecting a front obstacle based on the traveling environment ahead of the host vehicle detected by the traveling environment detection means and obtaining a collision prediction time based on the distance and relative vehicle speed between the front obstacle and the vehicle. When,
In the vehicle driving support device comprising: an automatic brake control unit that activates an automatic brake when the predicted collision time obtained by the predicted collision time calculation unit is less than a brake assist determination time.
The vehicle driving support device according to claim 1, wherein the automatic brake control means releases the automatic brake when detecting a collision avoidance operation by a driver. 2. The vehicle driving support apparatus according to claim 1, wherein the automatic brake control means determines that the collision avoiding operation is detected when depression of an accelerator pedal is detected. 2. The automatic brake control device according to claim 1, wherein when the automatic brake is operated, the throttle valve is fully closed, and when the collision avoidance operation is detected, the throttle valve is interlocked with the depression of the accelerator pedal. Or the driving assistance apparatus for vehicles of 2.

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