JP2004021815A - Rear-end collision alarm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alarm an rear-end collision according to an actual driving characteristic of a vehicle. <P>SOLUTION: This system is provided with a distance measurement means 2 which measures the distance to a preceding vehicle 200, a speed measurement means 3 which measures speed of an own vehicle 100, a relative speed calculating means 4 which detects relative speed between the own vehicle 100 and the preceding vehicle 200, and the following means based on the relative speed between the own vehicle 100 and the preceding vehicle 200. Thus, it is provided with a set-distance between the cars calculating means 5 which calculates set-distance between the own car 100 and the preceding car 200, a collision driving situation judging means 8 which predicts a collision driving situation that the own car 100 collides with the preceding car 200, a set-distance correcting means 9 which corrects the set-distance calculated at the set-distance between the cars calculating means 5 based on the collision driving situation, a risk rate judging means 6 which judges the collision risk rate between the own car 100 and the preceding car 200 based on the set-distance calculated at the set-distance between the cars calculating means 5 or the corrected set-distance and the distance to the preceding car 200, and an alarm means 7 which raises an alarm based on the collision risk rate. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rear-end collision warning device that calculates a possibility of a rear-end collision with a preceding vehicle and issues a warning to a driver.
[0002]
[Prior art]
An example of a rear-end collision warning device that calculates a rear-end collision possibility with a preceding vehicle and issues a warning to a driver is disclosed in, for example, Japanese Patent Application Laid-Open No. H8-179042. This conventional rear-end collision warning device calculates a set inter-vehicle distance between a host vehicle and a preceding vehicle based on a vehicle speed of the host vehicle and a relative speed between the host vehicle and the preceding vehicle, and detects a driver's sideways operation. Then, the rear-end collision degree with the preceding vehicle is calculated based on the inter-vehicle distance to the preceding vehicle, the set inter-vehicle distance, and the side-by-side motion detection signal.
[0003]
[Problems to be solved by the invention]
However, the conventional rear-end collision warning device is configured to issue an alarm when it is determined that the possibility of rear-end collision is high based on an instantaneous driving situation or a driver's look-aside state. Even when the distance is shortened, an alarm is uniquely generated, and there is a problem that troublesomeness is generated.
[0004]
[Means for Solving the Problems]
A rear-end collision warning device according to the present invention includes a distance measuring unit that measures a distance to an object in front of the own vehicle, a vehicle speed measuring unit that measures a speed of the own vehicle, and a relative speed detection that detects a relative speed between the own vehicle and the object. Means, a set inter-vehicle distance calculating means for calculating a set inter-vehicle distance between the own vehicle and the object based on the speed measured by the vehicle speed measuring means and the relative speed detected by the relative speed detecting means; Based on the rear-end collision situation predicted by the rear-end collision state prediction means for predicting the rear-end collision state where the vehicle collides with the object, the set inter-vehicle distance calculated by the rear-end collision distance calculation means is calculated. The set inter-vehicle distance correction means to be corrected, the set inter-vehicle distance calculated by the set inter-vehicle distance calculation means or the set inter-vehicle distance corrected by the set inter-vehicle distance correction means, and measured by the distance measurement means. A rear-end collision degree determining unit that determines a rear-end collision degree between the host vehicle and the object based on the distance to the collision object, and an alarm that issues an alarm based on the rear-end collision degree determined by the rear-end collision degree determining unit. The above-mentioned object is achieved by providing means.
[0005]
【The invention's effect】
According to the rear-end collision warning device of the present invention, when determining the rear-end collision risk degree at which the own vehicle collides with the object based on the set inter-vehicle distance between the own vehicle and the object and the distance to the object, Predicts a rear-end collision situation in which the vehicle collides with an object and corrects the set inter-vehicle distance, so that not only an instantaneous traveling state but also a rear-end collision warning according to the actual traveling characteristics of the vehicle can be issued.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
-1st Embodiment-
FIG. 1 is a diagram showing a configuration of a rear-end collision warning device according to a first embodiment of the present invention. The rear-end collision warning device according to the first embodiment includes an inter-vehicle distance measurement unit 2, a vehicle speed measurement unit 3, a relative speed calculation unit 4, a set inter-vehicle distance calculation unit 5, a risk degree determination unit 6, and an alarm unit 7. , A rear-end collision traveling state determining means 8 and a set inter-vehicle distance correcting means 9.
[0007]
The inter-vehicle distance measuring means 2 is, for example, a laser radar, and transmits a laser beam to the front of the vehicle, and measures an inter-vehicle distance L to the preceding vehicle 200 based on a time until the laser beam is reflected by the preceding vehicle 200 and returns. . The vehicle speed measuring means 3 is, for example, a vehicle speed sensor, and the speed V of the vehicle 100 _F Is measured. The measured vehicle speed V of the own vehicle 100 _F Is sent to the set inter-vehicle distance calculating means 5 and the rear-end collision traveling state determining means 8. The relative speed calculating means 4 is a calculating circuit mounted in the above-mentioned laser radar, and based on the inter-vehicle distance L to the preceding vehicle 200 measured by the inter-vehicle distance measuring means 2, the relative speed calculating means 4 Relative velocity V _R Is calculated. Calculated relative speed V _R Is sent to the set inter-vehicle distance calculating means 5.
[0008]
The set inter-vehicle distance calculating means 5 calculates the relative speed V calculated by the relative speed calculating means 4. _R And the vehicle speed V measured by the vehicle speed measuring means 3 _F Based on this, the set inter-vehicle distance La with the preceding vehicle 200 is calculated. When a predetermined condition described later is satisfied, the set inter-vehicle distance La is corrected using a set inter-vehicle distance correction coefficient (hereinafter, simply referred to as a correction coefficient) k sent from the set inter-vehicle distance correction means 9. The calculated set inter-vehicle distance La is sent to the risk degree judgment means 6 and the rear-end collision traveling state judgment means 8. The set inter-vehicle distance calculating means 5 calculates the relative speed V _R And the vehicle speed V of the vehicle 100 _F Vehicle speed V of preceding vehicle 200 based on _L Is calculated, and the calculated vehicle speed V of the preceding vehicle 200 is calculated. _L Is calculated based on the deceleration α of the preceding vehicle 200.
[0009]
The risk degree judging means 6 collides between the host vehicle 100 and the preceding vehicle 200 based on the set inter-vehicle distance La calculated by the set inter-vehicle distance calculating means 5 and the inter-vehicle distance L measured by the inter-vehicle distance measuring means 2. A risk level D2 indicating a risk is determined. The determined risk degree D2 is sent to the alarm unit 7. The warning unit 7 issues a warning that prompts the driver to decelerate based on the risk level D2 determined by the risk level determination unit 6. The alarm can be issued using a speaker or an indicator (not shown).
[0010]
The rear-end collision traveling state determining means 8 calculates the vehicle speed V of the preceding vehicle 200 calculated by the set inter-vehicle distance calculating means 5. _L And deceleration α, and the vehicle speed V of the own vehicle 100 measured by the vehicle speed measuring means 3 _F And a rear-end collision traveling state D1 with the preceding vehicle is determined based on the inter-vehicle distance L measured by the inter-vehicle distance measuring means 2. Here, the rear-end collision traveling state D1 refers to a state in which the traveling vehicle 200 collide with the traveling preceding vehicle 200 when the traveling state of the own vehicle 100 and the preceding vehicle 200 continues as it is, or the own vehicle 100 after the preceding vehicle 200 decelerates and stops. Is a driving situation in which a rear-end collision occurs. The method of determining the rear-end collision traveling state D1 will be described later.
[0011]
The set inter-vehicle distance correcting means 9 calculates a correction coefficient k for correcting the set inter-vehicle distance La based on the rear-end collision traveling state D1 determined by the rear-end collision traveling state determining means 8. A method of correcting the set inter-vehicle distance La using the correction coefficient k based on the rear-end collision situation D1 will be described later. The set inter-vehicle distance calculating means 5, the risk degree judging means 6, the rear-end collision situation judging means 8, and the set inter-vehicle distance correcting means 9 are realized by a control device including a CPU and its peripheral devices.
[0012]
A method in which the rear-end collision traveling state determination means 8 determines the rear-end collision traveling state D1 will be described. FIG. 2 is a diagram illustrating a positional relationship between the preceding vehicle 200 and the host vehicle 100. 2A is a diagram illustrating a situation before the preceding vehicle 200 decelerates, FIG. 2B is a diagram illustrating a situation when the preceding vehicle 200 starts decelerating, and FIG. FIG. 9 is a diagram illustrating a situation when t seconds have elapsed since the preceding vehicle 200 started decelerating.
[0013]
As shown in FIG. 2A, the vehicle speed of the preceding vehicle 200 when the preceding vehicle 200 is decelerated is represented by V _L0 And the vehicle speed of the vehicle 100 _F0 And In this state, the inter-vehicle distance between the host vehicle 100 and the preceding vehicle 200 when the preceding vehicle 200 starts to decelerate is represented by L. ₀ (See FIG. 2B). When the preceding vehicle 200 starts decelerating, the relative speed calculated by the relative speed calculating means 4 is represented by V _R0 Then, the vehicle speed V of the preceding vehicle 200 _L0 Is represented by the following equation (1).
V _L0 = V _F0 -V _R0 … (1)
The deceleration α of the preceding vehicle 200 is the vehicle speed V calculated by the equation (1). _L0 Can be obtained by performing a time differential operation (Equation (2)).
α = dV _L0 /Dt...(2)
[0014]
Distance L that host vehicle 100 advances in t seconds after preceding vehicle 200 starts decelerating _L (T) and the distance L that the following vehicle 200 travels _F (T), the vehicle speed V of the host vehicle after t seconds have elapsed. _L (T) is represented by equations (3), (4), and (5), respectively.
L _L (T) = V _L0 (T)-(1/2) αt ² … (3)
L _F (T) = V _F0 t ... (4)
V _L (T) = V _L0 -Αt (5)
[0015]
The inter-vehicle distance ΔL (t) after elapse of t seconds is L _L (T), L _F (T), L ₀ And is expressed by the following equation (6).
ΔL (t) = L _L (T) + L ₀ -L _F (T) ... (6)
Further, when the condition of the following expression (7) is satisfied, the own vehicle 100 will collide with the preceding vehicle 200.
ΔL (t) ≦ 0 (7)
[0016]
The time t1 from when the preceding vehicle starts to decelerate to when it stops is V _L From (t) = 0, it is expressed by the following equation (8).
t1 = V _L0 / Α… (8)
Therefore, the conditional expression in which the own vehicle 100 collides with the preceding vehicle 200 after the preceding vehicle 200 starts to decelerate and stops, is expressed by the following expression (9) using the expressions (3) to (8). You.
L ₀ ≧ V _L0 (2V _F0 -V _L0 ) / 2α (9)
When the condition of the expression (9) is satisfied, that is, a driving situation in which the host vehicle 100 collides with the preceding vehicle 200 after the preceding vehicle 200 decelerates and stops, is a driving situation in which a rear-end collision is likely to occur, and a type of behavior in which many accidents occur. It is.
[0017]
Therefore, the conditional expression in which the own vehicle 100 collides with the preceding vehicle 200 during the travel from the start of the deceleration to the stop of the preceding vehicle 200 is expressed by the following expression (10).
0 ≦ L ₀ <V _L0 (2V _F0 -V _L0 ) / 2α (10)
When the condition of the expression (10) is satisfied, that is, a traveling situation in which the own vehicle 100 collides with the preceding vehicle 200 during traveling is a traveling situation in which a rear-collision is relatively unlikely to occur, and is a behavior type with few accidents. . Therefore, the rear-end collision traveling state determining means 8 determines the rear-end collision traveling state D1 using Expressions (9) and (10).
[0018]
FIG. 3 is a flowchart of an embodiment showing a processing procedure of calculating the set inter-vehicle distance La and calculating the degree of rear-end collision with the preceding vehicle 200. The process starting from step S1 is performed, for example, at predetermined time intervals in the CPU of the control device described above. In step S <b> 1, the set inter-vehicle distance calculating means 5 calculates the inter-vehicle distance L from the preceding vehicle 200 measured by the inter-vehicle distance measuring means 2 and the vehicle speed V of the own vehicle 100 measured by the vehicle speed measuring means 3. _F And take in. In the next step S2, the relative speed calculating means 4 calculates the relative speed V between the host vehicle 100 and the preceding vehicle 200. _R Is calculated. Relative speed V calculated by set inter-vehicle distance calculating means 5 _R , The process proceeds to step S3. Note that the relative speed V _R Is plus in the direction approaching the preceding vehicle 200 and minus in the direction away from it.
[0019]
In step S3, the set inter-vehicle distance calculating means 5 determines the vehicle speed V of the host vehicle 100. _F And relative speed V _R Vehicle speed V of preceding vehicle 200 based on _L And the deceleration α of the preceding vehicle 200 is calculated. In the next step S4, the set inter-vehicle distance calculating means 5 sets the vehicle speed V of the own vehicle 100 acquired in step S1. _F And the relative speed V calculated in step S2 _R Based on this, the set inter-vehicle distance La is calculated. After calculating the set inter-vehicle distance La, the process proceeds to step S5.
[0020]
In step S5, the deceleration of the preceding vehicle 200 is determined based on the deceleration α calculated in step S3. If the deceleration of the preceding vehicle 200 is determined, the process proceeds to step S6, and if it is determined that the vehicle is not decelerated, the process proceeds to step S10.
[0021]
In step S6, the set inter-vehicle distance calculating means 5 determines that the vehicle speed V of the own vehicle 100 during the deceleration of the preceding vehicle 200 _F0 And the vehicle speed V of the preceding vehicle 200 _L0 And deceleration α, and the following distance L ₀ And read. When these parameters are read, the process proceeds to step S7. In step S7, a conditional expression ΔL for determining the rear-end collision situation D1 is calculated by the following equation (11). Note that ΔL represented by Expression (11) is derived from Expression (9) or (10) described above.
ΔL = V _L0 (2V _F0 -V _L0 ) / 2α (11)
[0022]
After calculating the conditional expression ΔL, the process proceeds to step S8. In step S8, the inter-vehicle distance L read by the rear-end collision traveling state determination means 8 in step S6. ₀ Then, the rear-end collision traveling state D1 is determined based on the conditional expression ΔL calculated in step S7. That is, the inter-vehicle distance L ₀ Is greater than or equal to ΔL, it is determined that the vehicle 200 is in a rear-end collision state in which the preceding vehicle 200 starts decelerating and stops and then collides. In this case, since there is a high possibility that the vehicle will collide with the preceding vehicle 200, the process proceeds to step S9 in order to correct the set inter-vehicle distance La calculated in step S4. In step S9, in order to make the set inter-vehicle distance La longer, the set inter-vehicle distance La calculated in step S4 is multiplied by a correction coefficient k (> 1) to calculate the corrected set inter-vehicle distance La (Equation ( 12)).
La = k · La (12)
In the present embodiment, k = 1.6. After correcting the set inter-vehicle distance La, the process proceeds to step S10.
[0023]
On the other hand, in step S8, the inter-vehicle distance L ₀ Is smaller than ΔL, it is determined that the own vehicle 100 is in a rear-end collision while the preceding vehicle 200 is traveling. In this case, since the vehicle is in a traveling state in which a rear-end collision is unlikely to occur, the process proceeds to step S10 without correcting the set inter-vehicle distance La.
[0024]
In step S10, the risk degree determination means 6 compares the inter-vehicle distance L captured in step S1 with the set inter-vehicle distance La calculated in step S4 or the set inter-vehicle distance La after correction in step S9. To determine the possibility of collision. When La> L holds, it is determined that the rear-end collision possibility is high, and the process proceeds to step S11. In step S11, an alarm is issued by the alarm means 7 to urge the driver to decelerate. On the other hand, when La ≦ L is satisfied in step S10, it is determined that the possibility of a rear-end collision is low, and the process returns to step S1.
[0025]
According to the rear-end collision warning device in the first embodiment, the vehicle speed V of the vehicle 100 _F And the relative speed V with respect to the preceding vehicle 200 _R The set inter-vehicle distance La is calculated on the basis of the following formula (Step S4), and the possibility of collision is determined by comparing the inter-vehicle distance L with the preceding vehicle 200 and the set inter-vehicle distance La (Step S10). At this time, when it is determined that the preceding vehicle 200 is decelerating (step S5), the vehicle speed V of the host vehicle 100 at that time is determined. _F0 And the vehicle speed V of the preceding vehicle 200 _L0 And deceleration α, and the following distance L ₀ Is used to calculate a conditional expression ΔL for determining the rear-end collision situation D1 (step S7), and the inter-vehicle distance L is calculated. ₀ The rear-end collision traveling state D1 is determined based on the conditional expression ΔL (step S8). If it is determined that the rear-end collision traveling state D1 is a rear-end collision traveling state in which the preceding vehicle 200 starts decelerating and stops and then collides, the possibility of rear-end collision with the preceding vehicle 200 is high. Therefore, the set inter-vehicle distance La is corrected. A new set inter-vehicle distance La is calculated (step S9). Thereby, the running conditions of the preceding vehicle 200 and the own vehicle 100 when the preceding vehicle 200 starts to decelerate, and the inter-vehicle distance L ₀ Can be determined using the set inter-vehicle distance La in consideration of the above, it is possible to prevent a troublesome alarm based on an instantaneous collision risk from being issued. That is, it is possible to issue an appropriate rear-end collision warning based on the traveling situation viewed on the time axis.
[0026]
The rear-end collision traveling state determination means 8 predicts the rear-end collision traveling state D1 when the deceleration of the preceding vehicle 200 is determined, so that the rear-end collision traveling state can be predicted in a state where there is a high possibility of a rear-end collision. In addition, the prediction of the rear-end collision traveling state is based on the speed V of the own vehicle 100 when it is determined that the preceding vehicle 200 is decelerating. _F0 And the vehicle speed V of the preceding vehicle 200 _L0 And deceleration α, and the following distance L ₀ Therefore, it is possible to predict the rear-end collision traveling state according to the actual traveling state.
[0027]
The rear-end collision state determination means 8 performs one of a rear-end collision state in which the host vehicle 100 collides with the traveling front vehicle 200 and a rear-end collision state in which the host vehicle 100 collides after the preceding vehicle 200 decelerates and stops. Since the traveling state is predicted, an appropriate set inter-vehicle distance La can be calculated according to the predicted rear-end collision traveling state. That is, when it is predicted that the own vehicle 100 will collide after the preceding vehicle 200 has decelerated and stopped, the correction for increasing the set inter-vehicle distance La calculated by the set inter-vehicle distance calculation means 5 is performed. In addition, a troublesome alarm based on a momentary collision possibility can be prevented from being issued.
[0028]
-2nd Embodiment-
The configuration of the rear-end collision warning device according to the second embodiment is the same as the configuration of the rear-end collision warning device according to the first embodiment shown in FIG. The rear-end collision warning device according to the second embodiment is characterized in the processing performed by the rear-end collision traveling state determination means 8. Hereinafter, a processing procedure performed by the rear-end collision warning device according to the second embodiment will be described with reference to a flowchart illustrated in FIG.
[0029]
Among the processes performed in the flowchart illustrated in FIG. 4, the same processes as those performed in the flowchart illustrated in FIG. 3 are denoted by the same reference numerals. That is, the processing performed in steps S1 to S11 is the same as the processing according to the flowchart shown in FIG. 3, and a detailed description thereof will be omitted. In step S <b> 8, the rear-end collision traveling state determining means 8 determines that the inter-vehicle distance L during which the ₀ Is compared with the conditional expression ΔL calculated in step S7 to determine the rear-end collision traveling situation D1. That is, L ₀ When ≧ ΔL holds, it is determined that the vehicle 100 is in a rear-end collision traveling situation in which the own vehicle 100 collides after the preceding vehicle 200 stops after deceleration.
[0030]
However, under actual driving conditions, L ₀ As a rear-end collision situation when ≧ ΔL is established, (1) a rear-end collision situation where the own vehicle 100 follows the preceding vehicle 200 that has recognized that the self-vehicle 100 is following, and (2) a rear-end collision situation where the own vehicle 100 follows There is a driving situation in which the vehicle collides with a preceding vehicle 200 that does not recognize that the vehicle is in a stop, for example, a vehicle that has already stopped. The rear-end collision situation of (2) may occur when the distance to the preceding vehicle 200 is long. In this case, if the relative speed with respect to the preceding vehicle 200 is high, the risk of a rear-end collision increases, but the driver's caution is high because the inter-vehicle distance is long. That is, in the process of approaching the preceding vehicle 200, the interruption of another vehicle and the risk of collision with an object other than the preceding vehicle 200 are also conscious, so that it can be determined that the vehicle is in a situation in which a rear-end collision is unlikely to occur as a result.
[0031]
In the second embodiment, in order to distinguish between the rear-end collision situations (1) and (2), the inter-vehicle distance L during which the preceding vehicle 200 is decelerating is determined. ₀ Predetermined inter-vehicle distance L for comparison with _T Set. The rear-end collision traveling state determining means 8 calculates the following distance L ₀ Is greater than or equal to ΔL and a predetermined inter-vehicle distance L _T If smaller, it is determined that the vehicle is in the rear-end collision condition (1), and L ₀ > L _T Is established, it is determined that the vehicle is in the rear-end collision situation of (2). In the present embodiment, the predetermined inter-vehicle distance L _T Is set to 40 m.
[0032]
In the determination in step S8 of the flowchart shown in FIG. ₀ If it is determined that is less than or equal to ΔL, the process proceeds to step S12, and if it is determined that is less than ΔL, the process proceeds to step S10. In step S12, the inter-vehicle distance L ₀ Is the predetermined distance L _T It is determined whether it is smaller than. L ₀ <L _T Is satisfied, the above-described (1) rear-end collision traveling state, that is, the rear-end collision traveling state in which the own vehicle 100 collides after the preceding vehicle 200 following the deceleration stop, and the rear-end collision is likely to occur. The process proceeds to step S9 to correct the set inter-vehicle distance La. On the other hand, L ₀ <L _T In the case of (2), since the rear-end collision traveling state described in (2) above is a traveling state in which rear-end collision is unlikely to occur, the process proceeds to step S10 without correcting the set inter-vehicle distance La.
[0033]
According to the rear-end collision warning device in the second embodiment, the following distance L during deceleration of the preceding vehicle 200 is obtained. ₀ And the predetermined inter-vehicle distance L _T Based on this, it is determined whether there is a high possibility that the host vehicle 100 will collide with the preceding vehicle 200, and if it is determined that there is a high possibility of collision, the set inter-vehicle distance La is corrected. Further, it is possible to determine the degree of rear-end collision according to the actual driving behavior and the situation where a rear-end collision occurs. Conversely, L ₀ Even if the condition of ≧ ΔL is satisfied, if the rear-end collision possibility is low, the correction of the set inter-vehicle distance La is not performed, so that it is possible to prevent a troublesome alarm from being issued in a situation where the rear-end collision possibility is low. it can.
[0034]
The set inter-vehicle distance La is determined by the rear-end collision traveling state determining means 8 to be a traveling state in which the own vehicle 100 collides after the preceding vehicle 200 has decelerated and stopped, and the inter-vehicle distance during which the preceding vehicle 200 is decelerating is a predetermined distance. L _T When the distance is shorter, the lengthening correction is performed, so that it is possible to realize a more detailed rear-end collision warning suitable for the actual driving behavior.
[0035]
-Third embodiment-
FIG. 5 is a diagram illustrating a configuration of a rear-end collision warning device according to the third embodiment. The rear-end collision warning device according to the third embodiment includes an inattentive movement detection unit 10 in addition to the configuration of the rear-end collision alarm device according to the first embodiment shown in FIG. The inattentive motion detection means 10 detects an inattentive motion such as the driver turning sideways based on, for example, the position of the driver's viewpoint. The detected inattentive movement information D3 is sent to the risk degree determination means 6. The risk degree judging means 6 includes an inter-vehicle distance L between the vehicle and the preceding vehicle 200 measured by the inter-vehicle distance measuring means 2, a set inter-vehicle distance La calculated by the set inter-vehicle distance calculating means 5, and an inattentive motion detecting means. The rear-end collision risk level D2 is determined based on the inattentive motion information D3 detected at 10.
[0036]
FIG. 6 is a flowchart illustrating a control procedure performed by the rear-end collision warning device according to the third embodiment. Steps for performing the same processing in the flowchart shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted. In step S13, the set inter-vehicle distance calculating means 5 takes in the inattentive movement information D3 detected by the inattentive movement detecting means 10. When the inattentive movement information D3 is captured, the process proceeds to step S1. The processing performed in steps S1 to S8 is the same as the processing in steps S1 to S8 in the flowchart shown in FIG.
[0037]
In step S8, L ₀ If it is determined that the condition of ≧ ΔL is satisfied, the process proceeds to step S14. In step S14, it is determined whether or not the driver's inattentive operation has been detected based on the inattentive operation information D3 captured in step S13. If it is determined that the driver's inattentive operation has been detected, there is a high possibility that the vehicle will collide with the preceding vehicle 200, so the process proceeds to step S9 to correct the set inter-vehicle distance La. In step S9, the set inter-vehicle distance La calculated in step S4 is corrected using the correction coefficient k. However, when the driver is performing an inattentive operation, it can be said that the possibility of a rear-end collision is extremely high. Let k be, for example, 2.0. On the other hand, when the driver's inattentive operation is not detected, the process proceeds to step S10 without correcting the set inter-vehicle distance La, and the collision risk degree D2 is determined.
[0038]
According to the rear-end collision warning device according to the third embodiment, the set inter-vehicle distance is set in a rear-end collision state in which the host vehicle 100 collides after the preceding vehicle 200 stops after deceleration and when the driver's inattentive operation is detected. Since La is corrected, it is possible to issue a rear-end collision warning in consideration of the driving situation of the driver.
[0039]
In other words, by further including the inattentive movement detection means 10 for detecting the inattentive movement of the driver of the own vehicle 100, the rear-end collision traveling state is determined by the rear-end collision traveling state determination means 8 so that the own vehicle 100 collides after the preceding vehicle 200 stops. Is determined, and when the driver's inattentive motion detection means 10 detects the driver's inattentive motion, a correction to increase the set inter-vehicle distance La is performed, so that a rear-end collision warning taking into account the driver's attention to the front is realized. Becomes possible.
[0040]
The present invention is not limited to the above embodiment. For example, the correction coefficient k and the predetermined distance L _T Is not limited to the values described above. In addition, the processing up to the calculation of the set inter-vehicle distance La and the calculation of the rear-end collision risk degree has been described in one flowchart, but the correction calculation processing of the set inter-vehicle distance La may be performed as another routine. For example, in the case of the flowchart shown in FIG. 3, the processing of steps S1 to S4 and steps S10 and S11 may be a series of processing, and the correction calculation processing of the set inter-vehicle distance La performed in steps S5 to S9 may be performed in parallel. . In this case, when a new set inter-vehicle distance La is calculated in the correction calculation processing, the rear-end collision determination processing in step S10 is performed using the newly calculated set inter-vehicle distance La.
[0041]
The correspondence between the components of the claims and the components of the embodiment is as follows. That is, the following distance measuring means 2 is a distance measuring means, the vehicle speed measuring means 3 is a vehicle speed measuring means, the relative speed calculating means 4 is a relative speed detecting means, and the set following distance calculating means 5 is a set following distance calculating means and deceleration judgment. Means, a rear-end collision situation determination means 8, a rear-end collision situation prediction means, a set inter-vehicle distance correction section 9, a set inter-vehicle distance correction section, a risk degree judgment section 6, a rear-end collision risk degree judgment section, and an alarm section 7, an alarm section. Respectively.
[0042]
In the above-described embodiment, the deceleration of the preceding vehicle 200 is determined in step S5. However, the determination can be made by detecting the start of deceleration. In step S6, the host vehicle speed and the like can be changed throughout the deceleration. However, the detection may be replaced with the detection of the own vehicle speed or the like immediately before the preceding vehicle 200 decelerates. In the above-described embodiment, the correction for increasing the inter-vehicle distance is performed. However, it is needless to say that the correction for shortening the set inter-vehicle distance can be performed to reduce troublesomeness. Note that each component is not limited to the above configuration as long as the characteristic functions of the present invention are not impaired.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a rear-end collision warning device according to a first embodiment.
2A and 2B are diagrams showing a positional relationship between a preceding vehicle and a host vehicle, wherein FIG. 2A shows a situation before the preceding vehicle decelerates, and FIG. FIG. 2C is a diagram illustrating a situation when deceleration is started, and FIG. 2C is a diagram illustrating a situation when t seconds have elapsed since the preceding vehicle started decelerating.
FIG. 3 is a flowchart illustrating a processing procedure performed by the rear-end collision warning device according to the first embodiment;
FIG. 4 is a flowchart showing a processing procedure performed by the rear-end collision warning device according to the second embodiment;
FIG. 5 is a diagram showing a configuration of a rear-end collision warning device according to a third embodiment.
FIG. 6 is a flowchart illustrating a processing procedure performed by the rear-end collision warning device according to the third embodiment;
[Explanation of symbols]
2 ... inter-vehicle distance measuring means, 3 ... vehicle speed measuring means, 4 ... relative speed calculating means, 5 ... set inter-vehicle distance calculating means, 6 ... risk degree judging means, 7 ... alarm means, 8 ... rear-end collision situation judging means, 9 ... Set inter-vehicle distance correction means, 10 ... inattentive motion detection means, 100 ... own vehicle, 200 ... preceding vehicle

Claims (7)

Distance measuring means for measuring a distance to an object in front of the vehicle,
Vehicle speed measuring means for measuring the speed of the vehicle,
Relative speed detecting means for detecting a relative speed between the host vehicle and the object,
A set inter-vehicle distance calculating unit that calculates a set inter-vehicle distance between the host vehicle and the object based on the speed measured by the vehicle speed measuring unit and the relative speed detected by the relative speed detecting unit;
A rear-end collision traveling state prediction unit that predicts a rear-end collision traveling state in which the host vehicle collides with the object;
A set inter-vehicle distance correction unit that corrects the set inter-vehicle distance calculated by the set inter-vehicle distance calculation unit based on the rear-end collision situation predicted by the rear-end collision situation prediction unit;
On the basis of the set inter-vehicle distance calculated by the set inter-vehicle distance calculation means or the set inter-vehicle distance corrected by the set inter-vehicle distance correction means, and the distance to the object measured by the distance measurement means, A rear-end collision risk degree determining unit that determines a rear-end collision degree between a vehicle and the object,
A rear-end collision warning device comprising: an alarm unit that issues an alarm based on the rear-end collision risk degree determined by the rear-end collision degree determination unit. The rear-end collision warning device according to claim 1,
The apparatus further includes deceleration determining means for determining deceleration of the object,
The rear-end collision warning device, wherein the rear-end collision traveling state predicting unit predicts the rear-end collision traveling state when the deceleration determining unit determines that the object is decelerated. The rear-end collision warning device according to claim 1,
Object speed detecting means for detecting the speed of the object, based on the speed of the own vehicle measured by the vehicle speed measuring means and the relative speed detected by the relative speed detecting means,
A deceleration detecting unit configured to detect a deceleration of the object based on the speed of the object detected by the object speed detecting unit,
The rear-end collision situation predicting means is based on a speed of the own vehicle when the deceleration determining means determines the deceleration of the object, a speed of the object, a distance to the object, and a deceleration of the object. A rear-end collision warning device for predicting the rear-end collision traveling state. The rear-end collision warning device according to any one of claims 1 to 3,
The rear-end collision traveling state predicting means may perform one of a rear-end collision traveling state in which the own vehicle collides with the moving object and a rear-end collision traveling state in which the own vehicle collides after the object decelerates and stops. A rear-end collision warning device characterized by predicting a collision. The rear-end collision warning device according to claim 4,
The set inter-vehicle distance correction means is calculated by the set inter-vehicle distance calculation means when the rear-end collision state prediction means predicts that the own vehicle is in a rear-end collision traveling state after the object has decelerated and stopped. A rear-end collision warning device that performs a correction for increasing a set inter-vehicle distance. The rear-end collision warning device according to claim 4,
The set inter-vehicle distance correction unit is predicted to be in a rear-end collision state in which the own vehicle collides after the object is decelerated and stopped by the rear-end collision state prediction unit, and the distance to the object in which the object is decelerating. A rear-end collision warning device that performs a correction for increasing the set inter-vehicle distance calculated by the set inter-vehicle distance calculation means when is shorter than a predetermined distance. The rear-end collision warning device according to any one of claims 1 to 4,
Further comprising an inattentive operation detection means for detecting an inattentive operation of the driver of the vehicle,
The set inter-vehicle distance correction unit is configured to predict the rear-end collision state in which the subject vehicle collides after the object has decelerated and stopped by the rear-end collision state prediction unit, and that the inattention operation of the driver is performed by the inattention operation detection unit. A rear-end collision warning device that performs a correction for increasing the set inter-vehicle distance calculated by the set inter-vehicle distance calculation means when is detected.

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