JP2010052546A - Vehicle running control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To assure an occupant's safety further properly by reducing a speed of an own vehicle at a proper timing in consideration of presence or absence of a following vehicle when a collision with an obstacle ahead is predicted. <P>SOLUTION: The vehicle running control apparatus includes an obstacle detection means (10) that detects the obstacle present ahead of the own vehicle, a collision control means 3 that applies a braking force to the own vehicle by activating a brake device 31 when the collision of the own vehicle is predicted based on information input from the obstacle detection means (10), and a following vehicle detection means (11) that detects the following vehicle running behind the vehicle. When the collision with the obstacle ahead is predicted and the presence of the following vehicle is detected by a rear millimeter wave radar 11, the collision control means 3 activates the brake device 31 at an earlier time point compared with a case in which the following vehicle is not detected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  According to the present invention, when a collision of the host vehicle is predicted based on an obstacle detection unit that detects an obstacle existing in front of the host vehicle and input information from the obstacle detection unit, the brake device is operated to detect the obstacle. The present invention relates to a vehicle travel control device including a collision control unit that applies a braking force to the vehicle.

  Conventionally, for the purpose of reducing damage at the time of a vehicle collision, for example, when a collision with an obstacle detected in front of the host vehicle is predicted, the host vehicle is forcibly braked. As a device using such an automatic brake, for example, a vehicle braking force generator disclosed in Patent Document 1 below is known.

Specifically, in Patent Document 1, a distance sensor using reflection of laser light detects a distance between an obstacle such as a preceding vehicle existing in front of the host vehicle and the host vehicle, and a relative speed between the two. Then, based on both pieces of the detected information, it is determined whether or not braking is necessary to avoid contact with the obstacle. The braking force is generated.
JP 2004-17925 A

  By the way, if a subsequent vehicle is traveling behind the host vehicle when a collision with an obstacle ahead is predicted and the automatic brake is forcibly applied, the subsequent vehicle will move to the movement of the host vehicle suddenly decelerating. There is a risk that the following vehicle may collide with the host vehicle. In other words, if the automatic brake is applied uniformly regardless of the presence or absence of the following vehicle, the automatic braking may reduce the collision against the obstacle in front of the vehicle, but it may increase the possibility of a rear-end collision accident. In view of this, it has been required to further improve the safety of passengers.

  The present invention has been made in view of the above circumstances, and when a collision with an obstacle ahead is predicted, by decelerating the host vehicle at an appropriate timing considering the presence or absence of a following vehicle. An object of the present invention is to provide a vehicle travel control device that can ensure the safety of passengers more appropriately.

  In order to solve the above problems, the present invention predicts an obstacle detection unit that detects an obstacle existing in front of the host vehicle, and a collision of the host vehicle based on input information from the obstacle detection unit. Then, the vehicle travel control device includes a collision control unit that operates the brake device to apply a braking force to the host vehicle, and includes a subsequent vehicle detection unit that detects a subsequent vehicle traveling behind the host vehicle. And the collision control means, when a collision with a front obstacle is predicted and a succeeding vehicle is detected by the succeeding vehicle detecting means, the brake device is started from a point in time earlier than when no succeeding vehicle is detected. Is operated (claim 1).

  According to the present invention, when it is predicted that the host vehicle will collide with an obstacle ahead, when the succeeding vehicle is detected behind the host vehicle, the operation of the brake device starts compared to when the subsequent vehicle is not detected. Since the timing can be advanced, in the state where there is a following vehicle, the required braking force can be reduced by the amount that the start of braking is accelerated, and the reduction that occurs in the host vehicle due to the operation of the brake device is reduced. The speed can be relatively reduced. For this reason, when a collision with an obstacle ahead is predicted, the own vehicle will not decelerate at such a rapid deceleration that the following vehicle cannot respond, and the following vehicle will collide with the own vehicle. While effectively preventing the collision, it is possible to effectively alleviate or avoid the collision with the obstacle by starting the brake at an early stage, and there is an advantage that the safety of the occupant can be ensured more appropriately.

  As a preferred mode of the present invention, the collision control means advances the operation start timing of the brake device when it is determined that the succeeding vehicle detected by the succeeding vehicle detecting means is approaching the host vehicle. Item 2).

  Further, the collision control means advances the operation start timing of the brake device when it is determined that the following vehicle detected by the following vehicle detecting means is within a predetermined distance from the own vehicle.

  According to these configurations, when there is a succeeding vehicle that is likely to collide with the own vehicle, the following vehicle can collide with the own vehicle by applying an automatic brake early to avoid sudden deceleration. There is an advantage that it is possible to effectively prevent and protect the occupant more appropriately.

  In the present invention, when the operation timing of the brake device is advanced, the collision control means preferably controls the brake device so that a substantially constant deceleration is generated from the start to the end of braking. .

  According to this configuration, for example, it is possible to reliably decelerate the own vehicle at a constant deceleration and effectively ensure the safety of the occupant while effectively avoiding a situation in which a trailing vehicle crashes due to a sudden increase in deceleration, for example. There is an advantage.

  The travel control device for a vehicle according to the present invention preferably includes a collision detection means for detecting that the host vehicle has collided, and the collision control means detects the collision of the seat belt when a collision is detected by the collision detection means. Control for winding up the seat belt by operating the pretensioner mechanism is performed (claim 5).

  According to this configuration, even when a collision actually occurs, there is an advantage that the occupant can be effectively protected from the impact at the time of collision by appropriately restraining the occupant with the seat belt.

  As described above, according to the vehicle travel control device of the present invention, when a collision with a front obstacle is predicted, the host vehicle is decelerated at an appropriate timing considering the presence or absence of a following vehicle. There is an advantage that the safety of passengers can be secured more appropriately.

  FIG. 1 is a diagram schematically illustrating an overall configuration of a vehicle to which a vehicle travel control device according to an embodiment of the present invention is applied, and FIG. 2 is a block diagram illustrating a control system of the travel control device. 1 and 2 has an operation control unit 1 composed of a well-known CPU, various memories, and the like, and the operation control unit 1 controls the operation of each part of the vehicle during operation. Controlled.

  The operation control unit 1 is electrically connected to a plurality of sensors for detecting various information relating to the driving state of the vehicle and the surrounding conditions of the vehicle. Specifically, the operation control unit 1 travels behind the host vehicle with a front millimeter wave radar 10 (corresponding to the obstacle detection unit according to the present invention) that detects an obstacle existing in front of the host vehicle. The rear millimeter wave radar 11 (corresponding to the following vehicle detecting means according to the present invention) for detecting the following vehicle, the vehicle speed sensor 12 for detecting the traveling speed of the host vehicle, and the steering angle of the steering wheel 5 (FIG. 1) are detected. A collision sensor 15 comprising a steering angle sensor 13, a yaw rate sensor 14 for detecting the yaw rate acting on the vehicle, and a G sensor for detecting that the host vehicle has collided with an obstacle (corresponding to the collision detection means according to the present invention). And are connected to each other.

  The forward millimeter wave radar 10 includes a transmitter that transmits an object detection millimeter wave toward the front of the host vehicle, and a receiver that receives a millimeter wave (reflected wave) reflected by the object. (All are not shown) By measuring the time from the transmission time of the millimeter wave to the reception time of the reflected wave in order, the distance and relative speed between the vehicle and the obstacle ahead are calculated and detected. The detection result is output to the control unit 1 as an electrical signal. Examples of the obstacle that can be detected by the forward millimeter wave radar 10 include a preceding vehicle and an oncoming vehicle that travel in front of the traveling direction of the host vehicle, a parked vehicle left on the road, a stationary object, and the like.

  The rear millimeter wave radar 11 has basically the same structure as the front millimeter wave radar 10 except that it transmits a millimeter wave toward the rear of the host vehicle. The vehicle is configured to detect the presence or absence of a following vehicle traveling behind the host vehicle by receiving the reflected wave.

  As shown in FIG. 2, the operation control unit 1 has an automatic speed control means 2 and a collision control means 3 as functional elements.

  The automatic speed control means 2 performs so-called auto-cruise control such as automatically adjusting the traveling speed of the host vehicle to match a preset target speed. Specifically, the automatic speed control means 2 outputs an opening / closing operation signal to the throttle valve 30 of the engine when an operation unit 20 described later is operated by a driver to turn on the auto cruise function. By adjusting the engine speed or outputting an operation signal for adjusting the braking force to the brake device 31 of the vehicle, the traveling speed of the host vehicle is made to coincide with a predetermined target speed.

  However, when there is a preceding vehicle within a predetermined distance ahead of the host vehicle, the automatic speed control means 2 does not perform the control to match the traveling speed of the host vehicle to the target speed as described above, and The traveling speed of the host vehicle is controlled so as to follow the vehicle with a certain inter-vehicle distance. Specifically, the automatic speed control means 2 predicts the traveling path of the host vehicle based on input information from the vehicle speed sensor 12, the steering angle sensor 13, and the yaw rate sensor 14, and an appropriate value is set in the traveling path. Whether or not a preceding vehicle exists is determined based on the input information from the forward millimeter wave radar 10. When it is confirmed that an appropriate preceding vehicle exists in the traveling path of the own vehicle, the distance between the preceding vehicle and the own vehicle is determined by appropriately controlling the throttle valve 30 and the brake device 31. The traveling speed of the host vehicle is adjusted so as to be maintained constant.

  The collision control means 3 determines whether or not the own vehicle is likely to collide with the obstacle based on the distance and relative speed between the obstacle and the own vehicle detected by the forward millimeter wave radar 10. A function for judging (a function for predicting a collision) and a function for warning a passenger when the collision is predicted as a result and operating the brake device 31 at a predetermined timing to decelerate the host vehicle. is doing.

  Specifically, when it is predicted that the host vehicle will collide with an obstacle ahead, the collision control means 3 first comprises a display lamp or an alarm generating device provided on an instrument panel or the like in the passenger compartment. By operating the alarm device 32, the passenger is notified that the possibility of a collision is high. When a predetermined time elapses from the operation of the alarm device 32 and the collision is still unavoidable, the brake device 31 is operated to decelerate the vehicle and the occupant restraint seat belt. By actuating the seat belt tensioner 35 (the pretensioner mechanism according to the present invention) that winds up 40 (FIG. 1), the seat belt 40 is wound up with a predetermined tension to restrain the occupant.

  As shown in FIG. 2, the seat belt tensioner 35 includes a first pretensioner 36 and a second pretensioner 37. Among these, the first pretensioner 36 is constituted by, for example, an electric motor or the like, and is to such an extent that the slack of the seat belt 40 is eliminated after the collision is predicted by the collision control means 3 until the actual collision occurs. By winding the seat belt 40 with the set first tension, the seat belt 40 has a function of restraining the occupant with a restraining force that does not affect the occupant's collision avoidance operation. On the other hand, the second pretensioner 37 is composed of, for example, an inflator using explosives, and when a collision actually occurs, the second pretensioner 37 instantaneously winds the seat belt 40 with a second tension larger than the first tension. , It has a function of protecting the occupant from an impact at the time of collision by restraining the occupant with a strong restraining force.

  As shown in FIGS. 2 and 3, the steering wheel 5 is provided with an operation unit 20 for performing a predetermined operation related to the auto-cruise function. The operation unit 20 includes a main switch 21 and a cancel switch 22. , And a target vehicle speed adjustment switch 23.

  The main switch 21 is a switch for turning on the auto-cruise function. When the main switch 21 is pressed by the driver, the automatic speed control means 2 for automatically controlling the traveling speed of the host vehicle is provided. It is designed to switch to the operating state. Specifically, when the main switch 21 is pressed while the host vehicle is traveling at a predetermined speed or more, the current traveling speed is set as the target vehicle speed, and the traveling state at the target vehicle speed is Control to operate the throttle valve 30 and the brake device 31 so as to be maintained is performed by the automatic speed control means 2.

  The cancel switch 22 is a switch for turning off the auto cruise function. When the cancel switch 22 is pressed by the driver during the operation of the automatic speed control means 2, the automatic speed control means 2 is operated. Is switched to the non-operating state, and the automatic speed control by the means 2 is released.

  The target vehicle speed adjustment switch 23 is composed of a lever switch that can be operated in the vertical direction. When the switch 23 is operated in the vertical direction by the driver, the target vehicle speed during auto-cruising is set to increase or decrease by a predetermined speed. It has become. Specifically, each time the target vehicle speed adjustment switch 23 is operated upward (on the side where “+” is displayed in FIG. 3), the target vehicle speed is increased by, for example, 5 km / h. Each time the switch 23 is operated once downward (on the side where “-” is displayed in FIG. 3), the target vehicle speed is set to decrease by 5 km / h, and a new target increased or decreased in this way is set. The automatic speed control means 2 is configured to control the throttle valve 30 and the brake device 31 so that the traveling speed of the host vehicle matches the vehicle speed.

  Here, the timing at which the collision control means 3 operates the brake device 31 when a collision of the host vehicle is predicted will be described in detail. In the present embodiment, the operation start timing of the brake device 31 by the control of the collision control means 3 is set to a different timing depending on the presence or absence of the following vehicle traveling behind the host vehicle. That is, when a collision with a front obstacle is predicted based on input information from the front millimeter wave radar 10, the collision control means 3 determines whether a rear vehicle is detected by the rear millimeter wave radar 11. When the following vehicle is detected, the operation start timing of the brake device 31 is advanced compared to the case where the following vehicle is not detected.

  FIG. 4 is a time chart showing changes in braking force over time when the collision control means 3 performs automatic brake control. In this figure, the horizontal axis indicates time, and the vertical axis indicates the magnitude of the braking force. The solid line in the figure indicates a brake diagram when there is a following vehicle, and the broken line indicates a brake line when there is no following vehicle. Each figure is shown.

  First, automatic brake control performed when there is no following vehicle will be described using the broken line in FIG. If it is predicted that the host vehicle will collide with an obstacle ahead at the time t0 on the horizontal axis, the collision control means 3 will detect that the predetermined time (for example, about 1 second) has elapsed from the time t0. The brake device 31 is operated to generate a predetermined braking force B1. Then, at a time point tz after this state is maintained for a predetermined time (for example, about 0.5 seconds), the braking force of the brake device 31 is increased, so that a braking force B2 larger than the braking force B1 is automatically applied. This state is maintained until the time point tc at which the collision occurs and is applied to the vehicle (for example, for about 0.5 seconds).

Thus, when there is no following vehicle, the collision control means 3 controls the operation of the brake device 31 so that the host vehicle decelerates in steps. Hereinafter, a light brake (brake having a braking force B1) applied first when a collision is predicted is referred to as a primary brake, and a sudden brake (brake having a braking force B2) applied next is referred to as a secondary brake. . The magnitudes of the braking forces B1 and B2 can be set as appropriate. For example, the braking force B1 during the primary braking is such that a deceleration of about 1.2 m / s ² is generated in the host vehicle. As the braking force, the braking force B2 at the time of the secondary braking is set to a braking force at which a deceleration of about 6.0 m / s ² is generated.

On the other hand, when there is a following vehicle behind the host vehicle, as shown by a solid line in FIG. 4, a time tx when a relatively short time has elapsed from the collision prediction time t0, that is, the primary brake start time ty. The brake device 31 is operated at a time tx earlier than the time δ by the time δ (for example, when about 0.2 seconds have passed since the collision prediction time), and a predetermined braking force B0 is applied to the host vehicle. The braking force B0 is a value between the braking force B1 during the primary braking and the braking force B2 during the secondary braking (for example, a braking force that generates a deceleration of about 2.0 m / s ² ). The same braking force B0 is maintained until the collision occurrence time tc.

  Thus, when there is a following vehicle, the start timing of automatic braking by the collision control means 3 is advanced by a predetermined time (δ) from the start timing when there is no following vehicle, and the braking force ( B0) is set to an intermediate value of the two-stage braking force (B1, B2) applied when there is no following vehicle, and is maintained at a constant value until the end of braking. As a result, the total amount of braking (braking force × time) is substantially the same when the following vehicle is present and when there is no following vehicle.

  Next, a specific procedure of the control operation by the collision control means 3 that controls the brake control at the time of collision prediction as described above will be described with reference to the flowchart of FIG. When this flowchart starts, the collision control unit 3 determines whether or not there is an obstacle such as another vehicle or a stationary object in front of the host vehicle based on the input information from the forward millimeter wave radar 10. Is executed (step S1). Specifically, the traveling path of the host vehicle is predicted based on input information from the vehicle speed sensor 12, the steering angle sensor 13, and the yaw rate sensor 14, and whether or not there is any obstacle in the traveling path. Is determined based on the input information from the forward millimeter wave radar 10.

  When it is determined as YES in step S <b> 1 and it is confirmed that there is an obstacle ahead of the host vehicle, the collision control unit 3 determines whether the obstacle detected by the front millimeter wave radar 10 is between the host vehicle and the obstacle. Based on the distance and relative speed, control is performed to determine whether or not the host vehicle is likely to collide with an obstacle ahead (step S2). And when it determines with YES here and it is confirmed that the possibility of a collision is high, the control which operates the said alarm device 32 is performed in order to alert | report that to a passenger | crew and to call attention (step S3). ).

  Next, the collision control means 3 determines whether or not there is a subsequent vehicle behind the host vehicle based on the input information from the rear millimeter wave radar 11 (step S4). Then, when it is determined YES here and it is confirmed that the following vehicle exists, the following vehicle is detected based on the inter-vehicle distance and the relative speed between the own vehicle and the following vehicle detected by the rear millimeter wave radar 11. Control for determining whether the vehicle is approaching the host vehicle and whether the following vehicle is within a predetermined distance from the host vehicle (that is, whether the inter-vehicle distance is equal to or less than a predetermined threshold). Execute (Steps S5 and S6).

When it is determined NO in any of the above steps S4 to S6 and it is confirmed that there is no subsequent vehicle approaching within a predetermined distance from the own vehicle, the collision control means 3 is as shown by the broken line in FIG. The brake device 31 is operated at a time ty when a predetermined time has elapsed from the time point t0 when a collision with an obstacle ahead is predicted (a time point YES is determined in step S2). By generating the power B1, control for applying a primary brake for decelerating the host vehicle at a relatively small deceleration (for example, about 1.2 m / s ² ) is started (step S10).

When the application of the primary brake is started in this way, the collision control means 3 can check whether or not the collision with the obstacle can be avoided by checking the input information from the front millimeter wave radar 10 again. Is determined (step S11). Then, when it is determined as NO here and it is confirmed that the collision is unavoidable, the braking force of the brake device 31 is increased at a time tz when a predetermined time has elapsed from the start time ty of the primary brake. By generating a relatively large braking force B1, control for applying a secondary brake for decelerating the host vehicle at a fairly rapid deceleration (for example, about 6.0 m / s ² ) is started (step S12). Further, substantially simultaneously with this, the first pretensioner 36 of the seatbelt tensioner 35 is operated to execute a control for winding the seatbelt 40 with a first tension set to such an extent that the occupant is not excessively restrained ( Step S13). On the other hand, if it is determined as YES in step S11 and it is confirmed that the collision can be avoided, the process returns as it is without applying the secondary brake and winding the seat belt 40.

Next, when it is determined YES in steps S4 to S6, that is, when it is confirmed that there is a succeeding vehicle within a predetermined distance from the host vehicle and this succeeding vehicle is approaching. The operation will be described. In this case, as shown by the solid line in FIG. 4, the collision control means 3 operates the brake device 31 at a time point tx that is a predetermined time δ earlier than the start time ty of the primary brake performed in step S10, By applying a braking force B0 set to a value between the braking forces B1 and B2 applied in steps S10 and S12 to the host vehicle, a predetermined deceleration (for example, about 2.0 m) that does not cause sudden braking. / S ² or so), the control for decelerating the host vehicle is started (step S7). The automatic braking started in step S7 is maintained at the braking force B0 until the host vehicle collides with an obstacle unless it is determined in step S8 that the collision can be avoided.

  When the automatic braking with the braking force B0 is started in this way, the collision control means 3 can avoid the collision with the obstacle by reexamining the input information from the front millimeter wave radar 10 and the like. It is determined whether or not it is possible (step S8). And when it is determined as NO here and it is confirmed that a collision is unavoidable, the first pretensioner 36 of the seat belt tensioner 35 is operated so that the occupant is not excessively restrained. Control for winding up the seat belt 40 with the first tension is executed (step S9). On the other hand, if it is determined as YES in step S8, the process returns as it is without winding the seat belt 40.

  After operating the first pretensioner 36 in step S9 or step S13, the collision control means 3 determines whether the host vehicle collides with the obstacle based on the input information from the collision sensor 15. The control to perform is executed (step S14). And when it determines with YES here and it is confirmed that the collision (front collision accident) with the said obstacle has occurred, a passenger | crew is operated by operating the 2nd pretensioner 37 of the said seatbelt tensioner 35. Control is performed to wind up the seat belt 40 with the second tension set to such a degree that it is restrained by a considerably large restraining force (step S15). On the other hand, if it is determined NO in step S14, the process returns as it is without winding the seat belt 40 with the second tension.

  As described above, the vehicle travel control apparatus according to the present embodiment includes the front millimeter wave radar 10 serving as an obstacle detection unit that detects an obstacle present in front of the host vehicle, and the forward millimeter wave radar 10 from the front millimeter wave radar 10. When a collision of the host vehicle is predicted based on the input information, the collision control means 3 that activates the braking device 31 to apply a braking force to the host vehicle, and the subsequent vehicle detection that detects a subsequent vehicle that travels behind the host vehicle. And a rear millimeter wave radar 11 as means. Then, when the collision with the obstacle ahead is predicted and the rear vehicle is detected by the rear millimeter wave radar 11, the collision control means 3 starts the braking from an earlier time than when the subsequent vehicle is not detected. The device 31 is configured to operate. According to such a configuration, when a collision with an obstacle ahead is predicted, the safety of the occupant is more appropriately secured by decelerating the own vehicle at an appropriate timing in consideration of the presence or absence of the following vehicle. There is an advantage that you can.

  That is, in the above-described embodiment, when it is predicted that the host vehicle will collide with an obstacle ahead, if the succeeding vehicle is detected behind the host vehicle, the brake device 31 is compared to when the subsequent vehicle is not detected. Since the operation start timing is advanced, in the state where the following vehicle exists, the required braking force can be reduced by the amount corresponding to the earlier start of the brake. The generated deceleration can be made relatively small. For this reason, when a collision with an obstacle ahead is predicted, the own vehicle will not decelerate at such a rapid deceleration that the following vehicle cannot respond, and the following vehicle will collide with the own vehicle. While effectively preventing the collision, it is possible to effectively alleviate or avoid the collision with the obstacle by starting the brake at an early stage, and there is an advantage that the safety of the occupant can be ensured more appropriately.

  In particular, in the above embodiment, when it is determined that the following vehicle is within a predetermined distance from the own vehicle and is approaching the own vehicle, the operation start timing of the brake device is advanced. When there is a succeeding vehicle that is likely to collide with the host vehicle, the automatic braking is applied early to avoid sudden deceleration, thereby effectively preventing the following vehicle from colliding with the host vehicle. There is an advantage that can be protected more appropriately.

  In the above embodiment, the collision control is performed so that a constant deceleration (B0 in FIG. 4) is generated from the start to the end of braking when the operation start timing of the brake device 31 is advanced because there is a following vehicle. Since the means 3 controls the brake device 31, for example, it effectively avoids a situation in which, for example, a sudden increase in deceleration causes a rear-end collision of the following vehicle, and the vehicle is surely decelerated at a constant deceleration, thereby improving the safety of the passenger. There is an advantage that it can be secured more appropriately.

  In the above-described embodiment, when the collision of the host vehicle is detected by the collision sensor 15 (collision detection unit), the collision control unit 3 operates the seat belt tensioner 35 (more specifically, the second pretensioner 37). Since the seat belt 40 is wound up by operating the seat belt 40, even when a collision actually occurs, the passenger is properly restrained by the seat belt 40, so that There is an advantage that an occupant can be effectively protected from an impact.

  In the above embodiment, the front millimeter wave radar 10 and the rear millimeter wave radar 11 that transmit and receive millimeter waves are used to detect an obstacle ahead of the host vehicle or a succeeding vehicle behind the host vehicle. Means for detecting the vehicle is not limited to the millimeter wave radars 10 and 11. For example, a sensor that detects an object by transmitting / receiving a laser wave or an ultrasonic wave as a radar wave (detection wave) other than the millimeter wave may be used as the detection unit.

  Further, in the above embodiment, when it is confirmed that the following vehicle detected by the rear millimeter wave radar 11 is within a predetermined distance from the own vehicle and is approaching the own vehicle (that is, in steps S5 and S6). In both cases, the timing at which the collision control means 3 operates the brake device 31 is advanced. However, only one of the two conditions is determined, and the brake device 31 is determined based on the result. The operation start timing may be determined.

  In the above embodiment, the automatic braking in the presence of the following vehicle is performed by operating the brake device 31 so that a constant deceleration is generated from the start to the end of the braking. There is no need to decelerate the host vehicle. For example, the brake device 31 may be operated so that the deceleration gradually increases from the start of braking.

1 is a diagram schematically showing an overall configuration of a vehicle to which a vehicle travel control device according to an embodiment of the present invention is applied. It is a block diagram which shows the control system of the said travel control apparatus. It is a figure which shows the specific structure of the operation part for performing operation regarding an auto-cruise function. It is a time chart which shows change of braking power at the time of automatic braking in time passage. It is a flowchart which shows the specific procedure of the control action performed by the said traveling control apparatus.

Explanation of symbols

3 Collision control means 10 Forward millimeter wave radar (obstacle detection means)
11 Rear millimeter wave radar (following vehicle detection means)
15 Collision sensor (collision detection means)
31 Brake device 35 Seat belt tensioner (pre-tensioner mechanism)
40 seat belts

Claims (5)

Obstacle detection means for detecting an obstacle present in front of the host vehicle, and when a collision of the host vehicle is predicted based on input information from the obstacle detection means, the brake device is activated to apply braking force to the host vehicle. A vehicle travel control device comprising a collision control means for providing
It has a following vehicle detection means for detecting a following vehicle traveling behind the host vehicle,
When the collision with the obstacle ahead is predicted and the following vehicle is detected by the following vehicle detection unit, the collision control unit operates the brake device from a point in time earlier than when no following vehicle is detected. A travel control device for a vehicle. The vehicle travel control apparatus according to claim 1,
The collision control means advances the operation start timing of the brake device when the succeeding vehicle detected by the succeeding vehicle detecting means is determined to be approaching the host vehicle. apparatus. In the travel control device according to claim 1 or 2,
The vehicle running control characterized in that the collision control means advances the operation start timing of the brake device when it is determined that the following vehicle detected by the following vehicle detecting means is within a predetermined distance from the own vehicle. apparatus. The vehicle travel control apparatus according to any one of claims 1 to 3,
The vehicle travel control device according to claim 1, wherein when the operation timing of the brake device is advanced, the collision control means controls the brake device so that a substantially constant deceleration is generated from the start to the end of braking. In the travel control device for a vehicle according to any one of claims 1 to 4,
Equipped with a collision detection means for detecting the collision of the host vehicle,
The vehicle travel control apparatus according to claim 1, wherein the collision control means executes a control for winding up the seat belt by operating a pretensioner mechanism of the seat belt when a collision is detected by the collision detection means.

Images