JPH1011700A - Alarm device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alarm device which gives an alarm at an appropriate time in accordance with the change tendency of the distance between a vehicle and a preceding vehicle, makes the meaning of the alarm clear, and can improve driving sense by predicting the operation of automatic braking when the time till an operated automatic braking starting period becomes below a prescribed value. SOLUTION: The inclinations α and β of tangents C and D at present time T1 on a characteristic line A showing the change of the distance between the vehicles and a characteristic line B showing the necessary degree of automatic braking are operated. The intersection 6 of the tangents C and D is calculated based on the respective inclinations α and β, and time T2 in the intersection 6 is predicted as the operation start time of automatic braking. At time T4 when necessary time from present time T1 to predicted time T2 becomes the previously set threshold, t1, for example, collision alarm for predicting the operation of automatic braking is given in a form where light automatic braking is operated, for example. Thus, the operation of automatic braking can be predicted even if the relative speed is high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm device for a vehicle which generates an alarm according to the distance between a host vehicle and a preceding vehicle and performs a rear-end collision prevention operation.

[0002]

2. Description of the Related Art Conventionally, after detecting the possibility of a rear-end collision on the basis of the inter-vehicle distance to a preceding vehicle and the relative speed, an alarm (primary alarm, secondary alarm, etc.) is issued to a driver, and then an automatic brake is applied. Conventionally, as a rear-end collision preventive device that is activated, for example, a method of generating an alarm by a method as shown in FIGS.
In some cases, the operation timing of the automatic brake is controlled.

In FIGS. 3 and 4, reference numeral 30 denotes an example of a characteristic line (inter-vehicle distance line) indicating a change in the inter-vehicle distance between the host vehicle and the preceding vehicle. Reference numeral 31 denotes an inter-vehicle distance at which the danger of a collision between the host vehicle and the preceding vehicle is to be warned, and is obtained from the host vehicle speed, the relative speed between the host vehicle and the preceding vehicle, and the relative acceleration.
(Alarm line) and 32 indicate the inter-vehicle distance (automatic brake line) at which the automatic brake should be activated, and are obtained in the same manner as the alarm line 31 described above. FIG. 4 shows a case where the relative speed between the own vehicle and the preceding vehicle is larger than the case of FIG. 3, and the inter-vehicle distance decreases sharply as the relative speed increases.
Along with that, warning line 31, automatic brake line 3
Both are rising sharply.

In the control based on FIG. 3 and FIG. 4, the inter-vehicle distance becomes L2 and the inter-vehicle distance line 30 starts from time T11 when the inter-vehicle distance line 30 and the warning line 31 intersect. An alarm is output until a time T12 at which the automatic brake line 32 crosses, and braking by the automatic brake is started after the time T12.

In addition, an alarm is issued when the inter-vehicle distance exceeds a predetermined threshold value, and the threshold value is set to be larger when approaching the vehicle than when following the preceding vehicle. In some cases, an alarm is generated according to the traveling state (see Japanese Patent Application Laid-Open No. 7-242132).

[0006] In addition, there is an apparatus in which the amount of an alarm generated by a driver's operation during the generation of an alarm is reduced, thereby alleviating the operation of an alarm unnecessary for the driver (Japanese Patent Application Laid-Open No. 7-257302). reference).

[0007] The collision risk may be determined from the margin time from the current time to the start time of the collision avoidance operation, the marginal time change acceleration that is this time change amount, and the confidence of the marginal time change acceleration that is this time change amount. In some cases, a degree of collision is obtained, and a collision avoidance operation is performed based on the plurality of degrees of danger to cope with an error in data from a sensor or the like that detects an inter-vehicle distance (see JP-A-8-36697). ).

[0008]

However, in the above-described conventional alarm generation devices based on FIGS. 3 and 4, when the vehicle speed is high, the inter-vehicle distance changes suddenly as shown in FIG.
Since the alarm generation time T11 to T12 is shortened, and the time from the alarm to the operation of the automatic brake is shortened, there is a problem that the meaning of the alarm is ambiguous, and since the automatic brake is unexpectedly activated, the ride is stopped. There is also a problem that sensation becomes worse.

In addition, the above-described method of changing the threshold value of the inter-vehicle distance for generating an alarm between following and approaching traveling, and a method of performing an avoiding operation based on a collision risk based on a plurality of certainty factors. In addition, since the method of reducing the amount of warning generated by driving operation operates according to the following distance,
A warning cannot be issued at an appropriate time according to the tendency of the inter-vehicle distance to change, and as described above, there is a problem that the meaning of the warning becomes ambiguous and the riding sensation deteriorates.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an alarm can be generated at an appropriate time in accordance with a change tendency of a distance between a vehicle and a preceding vehicle, and the meaning of the alarm can be clarified.
It is an object of the present invention to provide a vehicle alarm device that can improve the ride feeling.

[0011]

As shown in FIG. 5, the invention according to claim 1 comprises an inter-vehicle distance detecting means 50 for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle, and the inter-vehicle distance per unit time. The inter-vehicle distance change speed calculating means 51 for obtaining the inter-vehicle distance change speed which is the amount of change, the braking necessity calculating means 52 for obtaining the necessity of the automatic braking at the inter-vehicle distance, and the amount of change in the necessity of braking per time. Braking necessity change speed calculating means 53 for obtaining a brake necessity change speed, and automatic brake operation start timing calculating means for predicting and calculating an automatic brake operation start time based on the inter-vehicle distance change speed and the brake necessity change speed. 54, and an alarm generating means 5 for generating an alarm for notifying the operation of the automatic brake when the time from the present time to the calculated automatic brake start timing is equal to or less than a predetermined value. It is characterized by comprising and.

A second aspect of the present invention is characterized in that, in the first aspect, the alarm is a light automatic brake.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are diagrams for explaining an alarm device for a vehicle according to an embodiment of the present invention. FIG. 1 is a diagram showing a configuration of the alarm device, and FIG. 2 is a diagram for explaining an operation of the alarm device. FIG.

In FIG. 1, reference numeral 1 denotes an alarm device for an automobile. The alarm device 1 includes a laser radar 2 as an inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle, and a vehicle speed of the own vehicle and the preceding vehicle. A vehicle speed sensor 7 to detect, a primary alarm and an alarm generating device 3 for generating an alarm for announcing the operation of the automatic brake; an automatic brake device 4 for operating the braking device without a braking operation of a driving vehicle; And an ECU 5 for controlling the operation of the automatic brake device 4 and the like.

The ECU 5 serves as an inter-vehicle distance change speed calculating means for obtaining an inter-vehicle distance change speed which is a change amount of the inter-vehicle distance from the laser radar 2 per unit time.
As braking necessity degree calculating means for calculating the necessity degree of braking at the inter-vehicle distance as a required inter-vehicle distance, as braking necessity degree changing speed calculating means for obtaining a braking necessity changing speed which is a change amount per hour of the braking necessity, As an automatic brake operation start time calculating means for predicting and calculating an automatic brake operation start time based on the inter-vehicle distance change speed and the braking necessity change speed, a time from the present time to the automatic brake start time is equal to or less than a predetermined value. When it does, it functions as an alarm generating means for specifically generating an alarm for notifying that the automatic brake is activated by the alarm generating device 3.

Next, the operation of the alarm device 1 of the present embodiment will be described with reference to FIG. When the inter-vehicle distance to the preceding vehicle is detected by the laser radar 2 and the vehicle speeds of the own vehicle and the preceding vehicle are respectively detected by the vehicle speed sensor 7, the necessity of braking at the inter-vehicle distance is determined by the inter-vehicle distance, the own vehicle speed, and the own vehicle. It is sequentially set based on changes in relative speed and relative acceleration with the preceding vehicle, and characteristic lines A and B are formed as map data over time as shown by solid lines in FIG. The characteristic line A indicates a change in the inter-vehicle distance, and the characteristic line B indicates a change in the necessity of braking at the inter-vehicle distance. Specifically, as the relative speed or relative acceleration between the host vehicle and the preceding vehicle increases, the inter-vehicle distance between the host vehicle and the preceding vehicle decreases sharply, and the necessity of braking increases sharply.

Next, assuming that the current time is T1, the slopes α and β of the tangents C and D at the time T1 of the characteristic lines A and B are calculated, and based on the slopes α and β, the slopes of the tangents C and D are calculated. The intersection 6 is calculated, and the time T2 at the intersection 6 is estimated as the operation start time of the automatic brake. In this case, the inclination of the tangent C corresponds to the inter-vehicle distance change speed, which is the amount of change per unit time of the inter-vehicle distance, and the inclination of the tangent D corresponds to the amount of change per hour of the necessity of the automatic braking at the inter-vehicle distance. It corresponds to the braking necessity change speed.

The estimated time T is calculated from the current time T1.
At the time T4 when the required time up to 2 reaches a predetermined threshold value set in advance, for example, at time t1, a rear-end collision warning for notifying the operation of the automatic brake is issued, for example, in the form of operating the light automatic brake.

As described above, the tangents C and C of the characteristic line A indicating the change in the inter-vehicle distance and the characteristic line B indicating the necessity of automatic braking.
From the intersection 6 of D, the operation time T2 of the automatic brake is predicted,
The rear-end collision warning is issued according to the required time until the expected time, so that even when the relative speed is large, the operation of the automatic brake can be announced in advance, and the meaning of the alarm is clarified to activate the automatic brake. Can be accurately transmitted to the driver. In addition, it is possible to improve the riding sensation without an unexpected operation of the automatic brake.

[0020]

As described above, in the vehicle alarm system according to the first aspect of the present invention, the inter-vehicle distance to the preceding vehicle is detected, the amount of change in the inter-vehicle distance per unit time, and the automatic braking at the inter-vehicle distance. The amount of change in the degree of necessity per hour is calculated, and the operation start timing of the automatic brake is predicted and calculated based on the change speed of the following distance and the change speed of the braking necessity. When the time until the time is less than a predetermined value, the automatic brake operation is notified in advance, so even if the relative speed is large, the automatic brake operation can be accurately transmitted to the driver, improving the riding feeling. There is an effect that can be.

In the vehicle alarm device according to the second aspect of the present invention, since the light automatic brake is operated as an alarm for notifying the operation of the automatic brake, the driver can be more clearly notified of the operation of the automatic brake. There is an effect that can be done.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle alarm device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram for explaining the operation of the alarm device.

FIG. 3 is a diagram showing characteristics of a conventional automobile alarm device.

FIG. 4 is a diagram showing characteristics of a conventional automobile alarm device.

FIG. 5 is a diagram showing the configuration of the claims of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 automotive alarm device 50 inter-vehicle distance detecting means 51 inter-vehicle distance change speed calculating means 52 braking necessity calculating means 53 braking necessity changing speed calculating means 54 automatic braking operation start timing calculating means 55 alarm generating means

Claims (2)

[Claims] An inter-vehicle distance detecting means for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle; an inter-vehicle distance change speed calculating means for obtaining an inter-vehicle distance change speed which is an amount of change in the inter-vehicle distance per unit time; Braking necessity calculating means for calculating the necessity of automatic braking at the following distance, braking necessity changing speed calculating means for obtaining a braking necessity changing speed which is an amount of change in the braking necessity per time, and the inter-vehicle distance changing speed An automatic brake operation start time calculating means for predicting and calculating an automatic brake operation start time based on the braking necessity change speed and a time from the present time to the calculated automatic brake start time has become a predetermined value or less. And a warning generating means for generating a warning for notifying the operation of the automatic brake. 2. The vehicle alarm device according to claim 1, wherein the alarm is a light automatic brake.