JP3002030B2 - Vehicle risk assessment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle risk evaluation device, and more particularly to a vehicle risk evaluation device capable of comprehensively evaluating a plurality of mutually related risk factors.

[0002]

2. Description of the Related Art In an autonomous traveling vehicle or the like, it is necessary to always evaluate the danger in the current traveling state and perform control to avoid the danger. For example, Japanese Patent Application Laid-Open No. 64-2691
No. 3 discloses a technique for such a risk evaluation. In general, when performing a risk evaluation of a vehicle, risk factors such as “colliding with a preceding vehicle” and “deviating from a running path” are defined in advance, and the risk level of each risk factor in the current driving state is obtained. Usually, a measure such as issuing an alarm is taken for the highest risk factor.

[0003]

However, in the conventional vehicle risk evaluation device, each risk factor is evaluated independently, and no consideration is given to the relationship with other risk factors. However, when the vehicle is actually run, a plurality of risk factors are often associated with each other. For example, in order to avoid a rear-end collision with a preceding vehicle, it is a common practice to steer the vehicle so as to deviate from the traveling path (for example, to avoid an adjacent empty lane). In such a case, the risk factor of "colliding with the preceding vehicle" should be given priority over the risk factor of "departure from the traveling road". Also "raise the skid"
The risk factor described above is a risk factor that should be prioritized in any case, because if a skid actually occurs, the vehicle may fall into a very dangerous state in which vehicle control is impossible.
Conventional risk assessment devices for vehicles do not take into account the interrelationships of such multiple risk factors and make independent decisions about each risk factor, making it impossible to perform an accurate risk assessment. Was.

Accordingly, an object of the present invention is to provide a vehicle risk evaluation device capable of comprehensively evaluating a plurality of mutually related risk factors.

[0005]

According to the present invention, there is provided an apparatus for evaluating the danger of a vehicle, comprising: an environmental state recognizing means for recognizing an external environmental state; an operating state recognizing means for recognizing a driving operation state of a driver; A state recognition means having a driving state recognition means for recognizing a driving state; and a plurality of danger factors defined for safe driving of the vehicle, each of which is determined on the basis of a recognition result of the state recognition means to obtain a danger level. A danger determining means for selecting a more important danger factor based on the danger level determined for the factor and a priority defined for each danger factor, and avoiding danger for the danger factor selected by the danger determination means To do
Danger coping means for notifying a driver of danger or outputting a driving operation amount to a vehicle.

[0006]

In the vehicle risk evaluation apparatus according to the present invention, the state recognition means recognizes the external environment state, the driving operation state by the driver, and the vehicle running state. On the other hand, a plurality of risk factors are defined in the risk determination means, and their priorities are defined. Further, an algorithm for determining the degree of danger for each danger factor is defined in the danger determination means, and the degree of danger is calculated based on the external environment state, the driving operation state of the driver, and the vehicle driving state. Can be A more important risk factor is selected by considering a priority defined in advance for each risk factor together with the risk level thus obtained. The danger coping means may notify the driver of danger of the selected danger factor to prompt a danger avoidance operation,
Alternatively, the driving operation amount is output to control the vehicle in a danger avoiding direction. After all, discussing multiple risk factors, taking into account the risks and priorities (cooperation and competition)
By doing so, which is the more important risk factor will be selected. Therefore, a more accurate risk evaluation can be performed as compared with a conventional evaluation device that individually handles each risk factor.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram showing a basic configuration of a vehicle risk evaluation device according to one embodiment of the present invention. The main components of this device are a state recognition unit 10, a danger judgment unit 2
0, danger coping means 30. The state recognizing means 10 includes an environmental state recognizing means 11 for recognizing an external environmental state based on detection signals from sensors 1 and 2 (for example, a video camera, an inter-vehicle distance sensor, etc.), and sensors 3 and 4 (for example, a steering angle). Operation state recognizing means 12 for recognizing a driver's driving operation state based on a detection signal of a sensor, an accelerator opening sensor, etc., and detection signals of sensors 5, 6 (for example, a vehicle speed sensor, an RPM sensor, etc.). Traveling state recognition means 13 for recognizing the traveling state of the vehicle. That is, each recognizing unit has a function of recognizing each state based on detection signals from various sensors 1 to 6 attached to the vehicle. The recognition result thus obtained is given from the state recognition means 10 to the danger judgment means 20. In this embodiment, specifically, the vehicle speed V, the steering amount φ, the deviation δ from the reference traveling position of the vehicle (for example, deviation from the center line), the direction θ of the vehicle with respect to the reference traveling direction, the inter-vehicle distance from the preceding vehicle d
1. The state recognizing means 10 recognizes the distance d2 between the vehicle and the following vehicle, the radius of curvature R of the traveling road, and the friction coefficient μ of the traveling road.

On the other hand, a plurality of danger factors relating to safe driving of the vehicle are defined in the danger determining means 20. In this example, risk factors A, B, and C are defined in blocks 21 to 23. This risk factor is inextricably linked to a factor generally referred to as a “safe desire agent”. The following is an example of a specific “safe desire agent” (the parentheses indicate the corresponding risk factors). (a) Agents who do not want to collide with the preceding vehicle (risk factors for collision with the preceding vehicle) (b) Agents who do not want to be collided with the following vehicle (risk factors for being collided with the following vehicle) (c) Want to run over the roadside No agent (risk factor protruding over the shoulder) (d) Agent who does not want to protrude from center line (risk factor protruding from center line) (e) Agent who does not want to overrun on the curve (overrun on the curve) Risk factor) (f) Agent who does not want to cause skid (risk factor for causing skid) For each risk factor, an algorithm for calculating the degree of risk based on the recognition result given from the state recognition means 10 is defined. . Therefore, when the recognition results of the state recognition means 10 are given to the blocks 21, 22, and 23 in FIG. 1, the degrees of risk Ua, Ub, and Uc are obtained. The determination unit 24 determines the degree of danger Ua, Ub, Uc
And three risk factors A, B, and C based on the priority defined in advance for the three risk factors A, B, and C.
Which are the most important. Information about the most important risk factors is provided to the risk handling means 30.

The danger coping means 30 performs a measure for avoiding danger for the danger factor determined to be the most important danger factor. This action is a danger alert to the driver,
Alternatively, it is a driving operation amount output to the vehicle for danger avoidance. In this embodiment, three treatments are selectively performed based on the degree of risk of the most important risk factor. In other words, if the risk is relatively small, the display “XX attention!” Is given to the driver, and if the risk is greater than this, the display “XX danger!” Is given to the driver. If the degree of danger is higher, a driving operation amount (for example, steering or brake operation) for avoiding danger is output.

The above is the basic configuration of the vehicle risk evaluation apparatus according to the present invention. Next, this apparatus will be described based on more specific embodiments. FIG. 2 is a block diagram showing an embodiment in which the device according to the present invention is applied to steering.
In this embodiment, the following three risk factors are prepared in the risk determination means 20. ◎ Danger factor A: “Driving off the road”: Priority 1 ◎ Danger factor B: “Risk against the preceding vehicle”: Priority 2 ◎ Danger factor C: “Skidding”: Priority 3 Here, each danger As the factors, the priorities are defined as described above (the higher the number, the higher the priority). Each value shown on the left side of FIG. 2 is a recognition result given from the state recognition means 10, and based on this recognition result, each of the risk levels U
a, Ub and Uc are determined. Specifically, the degree of risk is obtained based on the following algorithm. The risk level Ua for the risk factor A “departure from the traveling road” is determined based on the vehicle speed V, the steering amount φ, the vehicle deviation δ, and the vehicle direction θ. Specifically, for example, the shortest distances Lright and Lleft from the left and right ends of the traveling path are determined based on these amounts, and Ua = K · [(1 / Lright−1 / Ln) using constants K and Ln. ^{2/2 + 1 / Lleft -1} / Ln) may be determined the risk Ua by ^2/2 equation. The degree of risk Ub for the risk factor B “collides with the preceding vehicle” is determined based on the inter-vehicle distance d1 to the preceding vehicle and the vehicle speed V. Specifically, for example, by h1 = d1 / V becomes equation, calculated the time headway h1 of the preceding vehicle, the constant K, Ub = K · using hn (1 / h1-1 / hn) 2/2 becomes The degree of risk Ub may be obtained by the equation. The risk Uc for the risk factor C "cause skidding" is determined based on the radius of curvature R of the traveling road, the vehicle speed V, and the friction coefficient μ of the traveling road. Specifically, the lateral acceleration G applied to the vehicle is determined from the radius of curvature R and the vehicle speed V, and the degree of risk Uc is calculated by the following equation using a constant K: Uc = K · [1− (μ−G) / μ] Just ask.

In the apparatus according to the present embodiment, the degree of risk U thus obtained is classified into four ranks. That is, three set values Ucaution, Udanger, and Uoperation are defined, and rank 0 if U <Ucaution, rank 1 if Ucaution ≦ U <Udanger, rank 2 if Udanger ≦ U <Uoperation, and rank 2 if Uoperation ≦ U. Is rank 3. And in the case of rank 1, "XX attention!"
Danger information is given, and in the case of rank 2, "○ danger!"
In the case of rank 3, the driving operation amount is output. Therefore, in the case of rank 3, the operation amount is calculated. Since the embodiment shown in FIG. 2 is an embodiment in which the present invention is applied to steering, the driving operation amount is the steering amount φ. Then, a steering amount φ * that minimizes the degree of danger U is obtained, and a deviation Δφ = |
φ-φ * | is output as the operation manipulated variable. To explain this more specifically, for example, the danger level Ub for the above-mentioned danger factor B “collision with the preceding vehicle” is given. In the case of rank 2, a danger notification of "Risk collision!" Is issued to the driver, and in the case of rank 3, a steering amount deviation .DELTA..phi. Required to avoid a collision is given to the steering system of the vehicle. .

However, in the example shown in FIG. 2, three risk factors A, B, and C are defined as risk factors related to steering. Therefore, a risk level of rank 1 or higher may be obtained for a plurality of risk factors. In this case, it is not preferable to perform the danger notification and the driving operation amount output for all the danger factors. For example, risk factor A
Let us consider a case in which the risk Ua for the risk factor B is rank 1, the risk Ub for the risk factor B is rank 2, and the risk Uc for the risk factor C is rank 3. In this case, when all of the danger factors are addressed, the driver is informed of the danger warning of "Driving on the road!" And the danger notification of "Risk of rear-end collision" at the same time. Doing so can cause confusion. In addition, as for the danger factor C, since the steering amount control that does not cause skidding is automatically performed, there is a possibility that the steering control in the direction opposite to the steering by the driver may be performed. An object of the present invention is that when a plurality of risk factors compete as described above, a risk evaluation is performed in which both the risk level and the priority level of each risk factor are considered, and the risk factors are coordinated.

In the embodiment shown in FIG. 2, cooperative work is performed by the following method, and only one of the risk factors A, B, and C is selected as the most important risk factor. That is, the determination units 41 and 42 determine which of the danger ranks is higher, and preferentially select the higher one.
However, if the danger ranks are the same, the higher priority described above is selected with priority. For example, the risk level U
If both a and Ub are rank 2 and danger Uc is rank 1, the judgment unit 42 selects a higher-rank danger Ub from danger Ub and Uc. On the other hand, since the danger levels Ua and Ub have the same rank, the determination unit 41 selects the danger level Ub having a higher priority. Thus, the risk factor B is finally selected as the most important risk factor, and a measure corresponding to the risk level Ub is performed by the risk handling means 30. In other words, the danger notification "Risk of rear-end collision!" The risk level Uc indicates that there is a possibility of skidding, but is ignored because the rank is low. On the other hand, the risk level Ua indicates that there is a risk of deviating from the traveling road, but is ignored because the priority level is low. The driver can concentrate on the process for avoiding the rear-end collision with the preceding vehicle, after receiving the danger notification “Rear-end collision!” Indicating the evocation of the most important danger factor. Further, in the above example, when the rank of the danger degree Uc is 3 instead of 1, the danger factor C is selected as the most important danger factor, and steering control to avoid skid is automatically performed. Done. At this time, the danger information about the rear-end collision and the deviation from the traveling road is ignored.

FIG. 3 is a block diagram showing an embodiment in which the apparatus according to the present invention is applied with respect to speed. In this embodiment, the following two risk factors are prepared in the risk determination means 20. ◎ Danger factor D: "I am hit by a following vehicle"
: Priority 1 ◎ Risk factor E… "overrun occurs in the curve": Priority 2 Here, the priority (the higher the number, the higher the priority) is defined for each risk factor as described above. I have. Each value shown on the left side of FIG. 3 is a recognition result given from the state recognition means 10, and based on this recognition result, each of the risk levels U
d and Ue are required. For example, the degree of danger Ud is obtained based on the following distance d2 with the following vehicle and the vehicle speed V. Specifically, for example, by h2 = d2 / V becomes equation, calculated the time headway h2 for the following vehicles, the constant K, Ub = K · using hn (1 / h2-1 / hn) 2/2 becomes The degree of danger Ud may be obtained by the equation. The risk Ue is determined based on the radius of curvature R of the traveling road and the vehicle speed V. Specifically, a lateral acceleration G applied to the vehicle is obtained from the curvature radius R and the vehicle speed V, and the G and the curvature radius R are calculated.
The danger degree Ue may be obtained by the following function. These danger levels are divided into four ranks, as in the above-described embodiment. In the case of rank 3, the driving operation amount output (for example, the driving operation amount output for changing the vehicle speed V in the direction in which the danger level U becomes the smallest) is obtained.
Brake operation) is performed.

When two risk factors conflict with each other, a risk evaluation is performed in which both the risk levels and the priority levels of the respective risk factors are considered and the two risk factors are coordinated. That is, the determination unit 43 determines which rank of the risk level is higher, and preferentially selects the higher one. However, when the ranks of the risk levels are the same, the higher priority (that is, the risk factor E) described above is preferentially selected. For example, when both the danger levels Ud and Ue are rank 2, the determination unit 43 selects the danger level Ue with a higher priority.
In this case, the danger notification “overrun danger!” Is performed, and the danger notification “subsequent vehicle rear-end danger!” Is ignored.
In other words, priority is given to a measure for avoiding overrun of the own vehicle rather than a measure for avoiding a rear-end collision from another vehicle.

Although the present invention has been described based on several embodiments, the present invention is not limited to these embodiments, and can be implemented in various other modes.
For example, in the above-described embodiment, either one of the danger notification or the driving operation amount output is performed according to the rank of the degree of danger, but both may be performed simultaneously. In addition, more danger ranks may be provided, and the danger notification mode or the driving operation amount output mode may be changed for each rank.

Furthermore, in the above description, the risk factors corresponding to some "safe desire agents" have been exemplified.
In the present invention, any other risk factors may be used. For example, it is also possible to define the following risk factors related to the agent, which are not the "safe desire agent" itself. (a) Agent watching the approach of the vehicle ahead ahead (b) Agent watching the approach of the following vehicle (c) Agent watching the traffic in the adjacent lane (d) Agent judging a decrease in the friction coefficient μ of the road surface (e) Obstacle Agent for finding objects (f) Agent for finding sharp curves (g) Agent for measuring the line of sight (parallax)

[0018]

As described above, according to the vehicle risk evaluation apparatus of the present invention, a plurality of risk factors are evaluated in consideration of both the risk level and the priority level. Multiple risk factors can be comprehensively evaluated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a risk evaluation device for a vehicle according to the present invention.

FIG. 2 is a block diagram illustrating a principle of risk evaluation in a vehicle risk evaluation device in which the present invention is applied to steering.

FIG. 3 is a block diagram illustrating a principle of risk evaluation in a vehicle risk evaluation device to which the present invention is applied to speed.

[Explanation of symbols]

 1-6 Sensor 10 State recognition means 11 Environmental state recognition means 12 Operation state recognition means 13 Running state recognition means 20 Danger determination means 21 Risk factor A 22 Risk factor B 23 Risk factor C 24 Judgment unit 30 ... danger coping means 41-43 ... Judgment unit

──────────────────────────────────────────────────続 き Continued from the front page (56) References JP-A-1-298500 (JP, A) JP-A-63-38056 (JP, A) JP-A-57-157400 (JP, A) JP-A-4- 245600 (JP, A) JP-A-4-372100 (JP, A) JP-A-4-304600 (JP, A) JP-A-4-38600 (JP, A) JP-A-3-273498 (JP, A) JP-A-3-197252 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08G 1/00-1/16 B60K 31/00 B60R 21/00

Claims (3)

(57) [Claims] 1. A state having environmental state recognizing means for recognizing an environmental state of the outside world, operation state recognizing means for recognizing a driving operation state of a driver, and running state recognizing means for recognizing a running state of a vehicle. Recognition means, for each of a plurality of risk factors defined for the safe driving of the vehicle, a risk level is determined based on the recognition result of the state recognition means, and the risk level determined for each risk factor and each risk factor are determined in advance. Danger determination means for selecting a more important danger factor based on the defined priority; and danger notification for the driver and driving for the vehicle to avoid danger for the danger factor selected by the danger determination means. And a danger coping means for performing one or both of the manipulated variable output. 2. The risk assessment device for a vehicle according to claim 1, wherein at least three dangers relating to steering include “cause a skid”, “collide with a preceding vehicle”, and “disengage from a traveling road”. A risk evaluation device for a vehicle, wherein factors are defined, and one or both of danger notification and steering amount output are performed for the most important danger factors selected from the factors. 3. The risk evaluation device for a vehicle according to claim 1, wherein at least two risk factors of “causing an overrun in a curve” and “colliding with a following vehicle” are defined as the speed-related risk factors. And a danger notification and / or speed control output for the most important danger factor selected from the danger factors.