JP2005178622A - Safety controller of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform safety control for improving the safety of an occupant of one's own vehicle with timing as early as possible when it is forecasted that the own vehicle may collide with a preceding vehicle based on the behavior variation of a preceding vehicle. <P>SOLUTION: When it is detected that lateral slipping occurs based on the behavior variation of the preceding vehicle in an image signal having the photographed travel direction of the own vehicle, safety control such as warning processing, automatic braking processing, or the operation processing of an occupant crash protection device 130 is performed. Since the safety control is performed based on the occurrence of the lateral slipping as an abnormal behavior of the preceding vehicle, the safety control can be performed with earlier timing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle safety control device that executes safety control for enhancing the safety of an occupant of a host vehicle when a possibility of a collision with a preceding vehicle occurs.

  Conventionally, for example, Patent Document 1 discloses a driving support apparatus that prevents a traffic accident with another vehicle by determining the presence of a vehicle that cannot be visually recognized by the driver and appropriately notifying the driver. ing.

In this driving support device, travel information including the position, traveling direction, and vehicle speed of the host vehicle is detected, and the position, traveling direction, and vehicle speed of another vehicle are detected from a navigation device mounted on the other vehicle via a communication device. Object information including is acquired. Based on these travel information and object information, the possibility of contact between the host vehicle and another vehicle is determined. If there is a possibility of contact, the level of risk is determined. Then, when displaying the positional relationship between the host vehicle and the other vehicle on the map, the other vehicle is displayed in different colors according to the level of danger.
JP 2002-342899 A

  According to the driving support apparatus described above, the position of a vehicle or the like hidden behind an obstacle such as a building can be confirmed, which is effective in preventing a so-called encounter accident. However, the conventional driving assistance device is based on the premise that each vehicle is equipped with a navigation device having a communication function. For other vehicles that do not have such a navigation device, its position and risk of collision Cannot be reported.

  A so-called pre-crash safety system is also known that protects an occupant by, for example, winding a seat belt and restraining the occupant when a possibility of a collision with a preceding vehicle or the like occurs. In this pre-crash safety system, for example, the time to the collision (collision margin time) is calculated by dividing the distance to the collision target by the current value of the relative speed. When the collision margin time becomes equal to or less than a threshold time set with reference to the minimum time during which collision cannot be avoided, a seat belt hoisting operation or the like is started.

  Thus, the conventional pre-crash safety system considers only the distance and relative speed between the host vehicle and the collision target in order to determine the possibility of collision with the collision target. For this reason, even in a situation where there is a high possibility of a collision with the preceding vehicle, control that increases the safety of the passenger is executed until the relationship regarding the distance and relative speed with the preceding vehicle satisfies the above-described relationship. There is a problem with not being.

  The present invention has been made in view of the above-described points, and when it is predicted that there is a possibility of collision between the host vehicle and the preceding vehicle from the behavior change of the preceding vehicle, the host vehicle is as soon as possible. An object of the present invention is to provide a vehicle safety control device capable of executing safety control for improving the safety of passengers.

In order to achieve the above object, a vehicle safety control device according to claim 1 comprises:
Imaging means for imaging a predetermined range in the traveling direction of the host vehicle;
In the image signal picked up by the image pickup means, a detection means for extracting a preceding vehicle and detecting that a skid has occurred from a behavior change of the preceding vehicle;
And safety control means for executing safety control for enhancing the safety of the occupant of the host vehicle when the detection means detects that a skid has occurred in the preceding vehicle.

  When skidding occurs in the preceding vehicle, it is difficult for the driver of the succeeding vehicle to predict the subsequent travel locus of the preceding vehicle. For example, if the front wheel of the preceding vehicle skids, the steering will not work, hits an obstacle such as a card rail, rebounds on the road, or if the rear wheel of the preceding vehicle skids, spins Sometimes it falls into. In this way, it is very difficult to determine in a short time what traveling track the preceding vehicle that has fallen into an uncontrollable state will follow, and the following vehicle may collide with this preceding vehicle. Increases nature.

  Therefore, the vehicle safety control device according to the first aspect of the present invention, when it is detected from the behavior change of the preceding vehicle in the image signal obtained by imaging the traveling direction of the own vehicle, the safety of the occupant of the own vehicle. Execute safety control to enhance Thus, since safety control is performed based on the occurrence of skid, which is an abnormal behavior of the preceding vehicle, safety control can be performed at an earlier timing.

  According to a second aspect of the present invention, it is preferable that the safety control means gives an alarm to a passenger of the host vehicle as safety control. Thereby, the driver of the own vehicle can notice the abnormal behavior of the preceding vehicle at an early stage, and can perform a driving operation for avoiding a collision with the preceding vehicle with a margin.

  According to a third aspect of the present invention, the safety control means may automatically brake the host vehicle as the safety control. For example, even if a spin occurs in the preceding vehicle and the driver of the host vehicle that is the subsequent vehicle turns and the brake operation is delayed, by executing automatic braking, the speed of the host vehicle decreases. It is easy to avoid a collision with a preceding vehicle.

  Furthermore, as described in claim 4, the safety control means may operate an occupant protection device that reduces the collision damage of the occupant of the host vehicle as the safety control. As a result, even if the host vehicle collides with the preceding vehicle, the collision damage applied to the passenger of the host vehicle can be reduced.

According to a fifth aspect of the present invention, road surface μ estimation means for estimating a road surface friction coefficient (road surface μ) of a road surface on which the host vehicle travels is provided, and the road surface on which the host vehicle travels is determined to have a predetermined low μ. When it is determined that the road is a road, the safety control means preferably performs safety control.
For example, on a low μ road such as a snowy road or a frozen road, a side slip of a preceding vehicle or the like is likely to occur, and it becomes difficult for the driver of the own vehicle to avoid the preceding vehicle. For this reason, it is preferable to execute the above-described safety control particularly on a low μ road.

  According to a sixth aspect of the present invention, based on the detection result of the relative relationship detecting means for detecting the relative relationship including the relative speed and the relative distance between the own vehicle and the preceding vehicle, the own vehicle and the preceding vehicle. Determining means for determining the possibility of a collision with the vehicle. When the determining means determines that there is a possibility of collision between the host vehicle and the preceding vehicle, the safety control means performs safety control, particularly occupant protection. It may execute the operation of the apparatus. This is because even if the preceding vehicle spins, there is a possibility that there is no possibility of colliding with the host vehicle from the position and moving direction at that time.

  Hereinafter, a vehicle safety control device of the present invention will be described with reference to the drawings.

  In FIG. 1, the whole structure of the vehicle safety control apparatus in this embodiment is shown. As shown in the figure, the vehicle safety control device 200 includes an accelerator sensor 10, a steering sensor 20, a laser radar sensor 30, a vehicle speed sensor 40, a brake sensor 50, and a CCD camera 60, which are connected to a computer 70. .

  The vehicle safety control device 200 further includes a throttle driver 80, a brake driver 90, a steering driver 100, an automatic transmission controller 110, an alarm device 120, and an occupant protection device 130, each of which is a computer. 70 and is driven in accordance with a control signal from the computer 70.

  The computer 70 includes an input / output interface (I / O) and various drive circuits in addition to the CPU, ROM, and RAM. Since these hardware configurations are general, a detailed description of the configuration is omitted. When the computer 70 detects that the preceding vehicle exhibits an abnormal behavior such as spin in the image signal output from the CCD camera 60 that captures a predetermined range in the traveling direction of the host vehicle, the computer 70 collides with the preceding vehicle. In order to avoid this, the alarm device 120 is used to execute alarm processing for alerting the driver, or when the driver does not perform an operation for avoiding a collision, the brake driver 90 or the like is driven. The automatic braking process for automatically braking is executed. Further, when it is determined that the collision cannot be avoided, the occupant protection device 130 such as a pretensioner is operated to execute an occupant protection device operation process that reduces damage caused by the occupant's collision. The safety control process including the alarm process, the automatic braking process, and the occupant protection device operation process will be described in detail later.

  Further, the computer 70 has a lane maintaining control function for driving the host vehicle so as to maintain the traveling lane, and an inter-vehicle distance control function for driving the host vehicle following the preceding vehicle when there is a preceding vehicle. It has a speed control function. These control functions are executed by driving the throttle driver 80, the brake driver 90, the steering driver 100, the automatic transmission controller 110, and the like based on information from each sensor.

  The accelerator sensor 10 detects whether or not the driver has operated the accelerator pedal (On / Off). The detected accelerator pedal operation signal is used in the computer 70 to determine whether or not the driver has performed an avoidance operation on the preceding vehicle. The steering sensor 20 detects the amount of change in the steering angle of the steering wheel, and the computer 70 calculates the steering angle from the amount of change in the steering angle detected by the steering sensor 20. This steering angle is used to determine the possibility of a collision with a preceding vehicle and to determine the presence or absence of an avoidance operation.

  The laser radar sensor 30 irradiates a predetermined range in front of the vehicle with the laser beam, thereby detecting the distance from the reflecting object such as the preceding vehicle that reflects the laser beam, the relative speed, and the direction of the reflecting object with respect to the host vehicle. To do. These detection results are output to the computer 70 for each reflective object. The radar sensor 30 may detect an object using radio waves such as millimeter waves and microwaves, ultrasonic waves, or the like, in addition to detecting an object using laser light.

  The vehicle speed sensor 40 is a sensor that detects a signal corresponding to the rotational speed of the wheel. The brake sensor 50 detects whether or not the driver has operated the brake pedal (On / Off). These detection signals are also output to the computer 70, and are used when determining the presence of a collision determination or avoidance operation.

  The CCD camera 60 is an optical camera that is installed on the back side of a room mirror, for example, and is used as an imaging unit that captures a predetermined range in front of the host vehicle. Output. In the present embodiment, based on the image signal captured by the CCD camera 60, it is determined whether or not the preceding vehicle skids and exhibits an abnormal behavior such as spin. Furthermore, the computer 70 specifies the road surface state ahead of the host vehicle based on the image signal captured by the CCD camera 60, and estimates the road surface friction coefficient (road surface μ) from the specified road surface state. The method for estimating the road surface μ will also be described in detail later.

  The throttle driver 80, the brake driver 90, the steering driver 100, and the automatic transmission controller 110 all operate according to instructions from the computer 70. The throttle driver 80 adjusts the opening of a throttle valve (not shown) and controls the output of the internal combustion engine. The brake driver 90 adjusts the brake pressure, and the steering driver 100 drives the steering by generating rotational torque on the steering shaft. The automatic transmission controller 110 changes the gear position of the automatic transmission necessary for controlling the speed of the vehicle.

  The alarm device 120 is a device that generates an alarm sound and an alarm sound for alerting the driver, and outputs an alarm according to an instruction from the computer 70. As described above, the occupant protection device 130 is composed of, for example, a seat belt pretensioner. When the collision becomes unavoidable, the occupant protection device 130 increases the restraining effect of the occupant by the seat belt, thereby reducing the collision damage to the occupant. Reduce.

  Next, a safety control process that is executed when the preceding vehicle exhibits an abnormal behavior such as spin will be described in detail based on the flowchart of FIG.

  In the flowchart of FIG. 2, first, in step S10, the road surface μ is detected (estimated) based on the image signal photographed by the CCD camera 60. That is, a road surface state (for example, dry, wet, etc.) is specified from an image of the road surface ahead of the host vehicle photographed by the CCD camera 60, and a road surface μ corresponding to the specified road surface state is obtained from a conversion table prepared in advance. . Hereinafter, the specification of the road surface state and the conversion from the road surface state to the road surface μ will be specifically described.

  First, when the road surface state is specified from the road surface image captured by the CCD camera 60, for example, the luminance of each pixel of the road surface image is obtained, and the average luminance of the obtained luminance of each pixel of the road surface is calculated. Then, the calculated average brightness is compared with a preset brightness threshold, and when the average brightness is equal to or higher than the brightness threshold, the road surface state is specified as being wet, and when the average brightness is less than the brightness threshold. Specifies that the road surface condition is dry.

  Note that a plurality of brightness threshold values may be set to specify road surface conditions such as water film, freezing, and snow cover. Various methods for specifying the road surface condition have been proposed in the past, and the conventional specifying method is adopted without being limited to the method of specifying from the image of the CCD camera 60 or the like employed in the present embodiment. It may be a thing.

  Next, when the road surface μ is obtained from the road surface state, the identified road surface state is applied to the conversion table, and the road surface μ corresponding to the road surface state is obtained. For example, in the conversion table, if the road surface state is dry, the road surface μ is related to 0.8. In this way, the road surface μ corresponding to the road surface condition can be detected.

  The detection (estimation) of the road surface μ is not limited to the method described above. For example, the road surface μ is estimated based on weather information, road position information, information on weather conditions detected by sensors mounted on the vehicle, information on road surface conditions manually input by the driver, information obtained by attempting braking, etc. May be. Preferably, the current road surface μ is determined by substituting the wheel deceleration or vehicle speed reduction rate when the braking operation is performed into a built-in map representing the relationship between the wheel deceleration or vehicle speed reduction rate and the road surface friction coefficient. can do.

  Next, in step S20, by comparing the obtained road surface μ with a predetermined reference value, it is determined whether or not the current travel path of the host vehicle is a low μ road. When it is determined that the road is not a low μ road, the possibility of skidding in the preceding vehicle is low. Even if a side slip occurs in the preceding vehicle, the driver of the own vehicle can easily stop the own vehicle so as to avoid a collision with the preceding vehicle or avoid the preceding vehicle by steering. it can. Therefore, when it is determined that the road is not a low μ road, the process returns to step S10 without performing the processes after step S30.

  On the other hand, if it is determined in step S20 that the road is a low-μ road, there is a possibility that the preceding vehicle will exhibit an abnormal behavior such as spin, and the driver of the own vehicle will also advance by sudden braking, sudden steering, etc. It becomes difficult to avoid the vehicle. Therefore, in step S30, the preceding vehicle is extracted from the image signal captured by the CCD camera 60, and the behavior change of the preceding vehicle is determined.

  Here, if a side slip occurs on the front wheels of the preceding vehicle, as shown in FIG. 3, the vehicle does not bend even when the steering is turned, and proceeds toward the outside of the turning circle. At this time, if a guard rail is installed on the side of the road, the preceding vehicle may hit the card rail and rebound on the road. In addition, when the rear wheel of the preceding vehicle slips, it may fall into a spin state. In this way, when the preceding vehicle falls into an uncontrollable state, there is a high possibility that the following vehicle (own vehicle) will collide with the preceding vehicle. For this reason, in step S30, it is determined from the image signal whether or not a behavioral change that can be regarded as a skid has occurred in the preceding vehicle.

  For example, in the image signal, when the preceding vehicle crosses the white line defining the lane area, when the direction of the preceding vehicle differs from the direction of the lane by a predetermined angle or more, the traveling direction of the preceding vehicle and the angle formed by the lane differ by a predetermined angle or more. Cases are determined as abnormal behavior due to skidding.

  In step S40, it is determined whether or not skidding has occurred in the preceding vehicle based on the determination result in step S30. At this time, if it is determined that there is no abnormality in the behavior of the preceding vehicle and no skid has occurred, the process returns to step S10. On the other hand, if it is determined that skidding has occurred, the process proceeds to step S60.

  In step S60, the distance from the preceding vehicle, the relative speed, the heading of the preceding vehicle based on the own vehicle, the traveling direction of the own vehicle, the preceding vehicle, which are obtained from the detection signals of the sensors or the image signals of the CCD camera 60. The possibility of collision with the preceding vehicle is determined based on the moving direction of the vehicle. For example, if the travel prediction trajectory of the host vehicle and the travel prediction trajectory of the preceding vehicle are respectively calculated and the travel prediction trajectories of both vehicles approach within a predetermined distance at the same timing, there is a possibility of a collision. to decide.

  If it is determined in step S60 that there is a possibility of collision, in step S70, the alarm device 120 is used to perform an alarm process for generating an alarm indicating that there is a possibility of collision with the preceding vehicle. . Thereby, the driver of the own vehicle can notice the abnormal behavior of the preceding vehicle at an early stage, and can start the driving operation for avoiding the collision with the preceding vehicle.

  Subsequently, in step S80, it is determined whether or not a driving operation for avoiding a collision with a preceding vehicle is performed. If it is determined that an avoidance operation has been performed, the process of step S90 is skipped and the process proceeds to step S100. On the other hand, if it is determined that the avoidance operation has not been performed, a control signal for forcibly closing the throttle valve is output to the throttle driver 80 and the brake driver 90 is forcibly forced. A control signal for starting braking is output.

  That is, if a driving operation (for example, an operation to turn off the accelerator, an operation to turn on the brake, or an operation to steer the steering) is not performed after the alarm is generated, It can be assumed that the operation cannot be performed immediately. Therefore, in such a case, in order to easily avoid a collision with the preceding vehicle, the throttle valve is forcibly closed and a braking force is generated to reduce the speed of the host vehicle. That's right. At this time, the steering direction may be changed by driving the steering by the steering driver 100 so as to avoid the preceding vehicle.

  In step S100, it is determined whether or not a collision with a preceding vehicle can no longer be avoided. When it is determined that collision avoidance is impossible, a control signal for operating the occupant protection device 130 is output to the occupant protection device 130.

  That is, after the alarm is generated, the driver may collide with the preceding vehicle, and the collision with the preceding vehicle is performed regardless of the avoidance operation or the automatic braking described above. There are cases where it cannot be avoided. In this case, the occupant protection device 130 is operated to minimize the collision damage to the occupant.

  Whether or not collision avoidance is possible is determined based on the relative positional relationship between the preceding vehicle and the host vehicle, the vehicle state (for example, speed, acceleration / deceleration, steering rotation angle of the host vehicle, etc.), road surface condition, and the like. Based on the overall judgment.

  As described above, according to the present embodiment, when it is determined from the behavior change of the preceding vehicle that a skid has occurred in the preceding vehicle, it is considered that there is a possibility of colliding with the preceding vehicle. Carry out safety control to increase the safety of passengers. Thus, since safety control is performed based on the occurrence of skid, which is an abnormal behavior of the preceding vehicle, safety control can be started at an earlier timing.

  Note that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the process after step S30 (safety control process) in the flowchart of FIG. 2 is performed only when the road surface on which the vehicle travels is a low μ road. Regardless of the case, the safety control process may always be performed.

It is a block diagram which shows schematic structure of the vehicle safety control apparatus concerning embodiment. It is a flowchart which shows the safety control process performed when a preceding vehicle shows abnormal behaviors, such as a spin. It is explanatory drawing for demonstrating the behavior change of a preceding vehicle when a side slip generate | occur | produces in a preceding vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Acceleration sensor 20 Steering sensor 30 Laser radar sensor 40 Vehicle speed sensor 50 Brake sensor 60 CCD camera 70 Computer 80 Throttle driver 90 Brake driver 100 Steering driver 110 Automatic transmission controller 120 Alarm device 130 Crew protection device 200 Vehicle safety Control device

Claims (6)

Imaging means for imaging a predetermined range in the traveling direction of the host vehicle;
In the image signal picked up by the image pickup means, a detection means for extracting a preceding vehicle and detecting that a skid has occurred from a behavior change of the preceding vehicle;
A safety control device for a vehicle, comprising: safety control means for executing safety control for enhancing safety of an occupant of the host vehicle when the detection means detects that a skid has occurred in a preceding vehicle. .   The vehicle safety control device according to claim 1, wherein the safety control means gives an alarm to an occupant of the host vehicle as the safety control.   The vehicle safety control device according to claim 1 or 2, wherein the safety control means automatically brakes the host vehicle as the safety control.   The vehicle safety control according to any one of claims 1 to 3, wherein the safety control means operates an occupant protection device that reduces a collision damage of an occupant of the host vehicle as the safety control. apparatus. Road surface μ estimation means for estimating a road surface friction coefficient (road surface μ) of the road surface on which the host vehicle travels,
The safety control means executes the safety control when the road surface μ estimation means determines that the road surface on which the host vehicle travels is a predetermined low μ road. Item 5. The vehicle safety control device according to any one of Items 4 to 6. A relative relationship detecting means for detecting a relative relationship including a relative speed and a relative distance between the host vehicle and the preceding vehicle;
Determination means for determining the possibility of collision between the host vehicle and the preceding vehicle based on a detection result by the relative relationship detection means;
The safety control means executes the safety control when it is determined by the determination means that there is a possibility of collision between the host vehicle and the preceding vehicle. The vehicle safety control device according to any one of 4.

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