JP3063328B2 - Vehicle alarm system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm system for a vehicle, and more particularly to an alarm system for generating an alarm based on the distance between the vehicle and a preceding vehicle.

[0002]

2. Description of the Related Art Conventionally, a vehicle which aims to avoid the danger of a rear-end collision with a preceding vehicle, issues an alarm when the inter-vehicle distance from the preceding vehicle becomes a predetermined value or less, and prompts the driver to decelerate. Alarm devices have been proposed.

For example, in a rear-end collision warning device for an automobile disclosed in Japanese Utility Model Laid-Open Publication No. 2-71535, a safe inter-vehicle distance is calculated from a vehicle speed, an idling time, and a judgment time until a braking operation is performed. A configuration is shown in which an alarm is output when the distance becomes equal to or less than the safe inter-vehicle distance, the determination time can be selectively switched, and an alarm that matches the driving environment of the driver can be generated.

[0004]

As described above, by making it possible to appropriately switch the judgment time, an alarm can be generated according to the driver's skill, day or night, weather, or the like. At the time of monotonous driving such as road driving, the driver's consciousness level may decrease, and the environment changes from a driving environment with a normal high consciousness level. was there. In other words, immediately after the start of traveling with a sufficiently high consciousness, the setting of the judgment time is appropriate, and an alarm that matches the driver's feeling is generated. However, in a state where the consciousness starts to decrease, this judgment time is not necessarily It is not appropriate (it becomes longer than in normal operation), and it becomes necessary to output an alarm on the safer side.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to objectively evaluate the consciousness level of a driver and to generate an alarm according to the consciousness level. It is an object of the present invention to provide a vehicular alarm device.

[0006]

In order to achieve the above object, the present invention provides a vehicle speed detecting means 1 as shown in FIG.
An inter-vehicle distance detecting means 2 for detecting an inter-vehicle distance with a preceding vehicle;
An alarm for a vehicle, comprising: arithmetic means 3 for outputting an alarm signal based on a magnitude comparison between the inter-vehicle distance and a predetermined value corresponding to a vehicle speed; and alarm means 4 for generating an alarm based on the alarm signal from the arithmetic means 3. The system calculates the distance between the vehicle during braking and the distance between vehicles during normal operation in the same vehicle speed section.
Evaluation means 5 for evaluating the driver's consciousness level based on the average value and the standard deviation , and adjustment means 6 for adjusting the output timing of the alarm signal from the arithmetic means 3 according to the evaluation result by the evaluation means 5. It is characterized by the following.

[0007]

The vehicle alarm device of the present invention has the above-described configuration, and determines the driver's consciousness level based on the inter-vehicle distance average during normal driving, the inter-vehicle distance standard deviation, and the current inter-vehicle distance during brake operation. Evaluation is performed, and the output timing of the alarm is adjusted to a safe side according to the evaluation result.

[0008] That is, the driver's consciousness level can be grasped by the displacement from the following distance during normal driving.
By evaluating the displacement during normal operation using the standard deviation during normal operation, a more reliable evaluation becomes possible.
Since the alarm output timing is adjusted according to the evaluation of the consciousness level, an alarm is issued earlier in a state where the consciousness level is lowered, and the danger of a rear-end collision with the preceding vehicle can be reliably avoided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a vehicle alarm system according to the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of this embodiment. As an inter-vehicle distance detecting means, an inter-vehicle distance sensor 10 such as a radar device or a laser radar device is provided at a front portion of the vehicle. The detected inter-vehicle distance data is supplied to the microcomputer 14 via the bus 13. The microcomputer 14 includes a CPU 14a, a ROM 14b in which a predetermined control program is stored, and a RAM 14c for the calculation results of the CPU 14a, and performs the following calculation to supply an alarm signal to the alarm device 16 via the input / output port 15. And
This is a configuration that gives a warning to the driver.

That is, as a basic operation, the vehicle speed sensor 1
Based on the vehicle speed signal from No. 1, the safety inter-vehicle distance is calculated in the same manner as in the related art, and the safety inter-vehicle distance is compared with the current inter-vehicle distance. Then, the alarm 16 is activated. At this time, the safe inter-vehicle distance may be calculated from the vehicle speed, the idle running time, and the determination time as in the related art.

As described above, the microcomputer 14 compares the safe inter-vehicle distance with the safe inter-vehicle distance and activates the alarm device 16. The characteristic of the present embodiment is that the inter-vehicle distance during the brake operation and the inter-vehicle distance during the normal operation. The consciousness level of the driver is evaluated from the average distance value and the standard deviation, and the output timing of the alarm is adjusted according to the evaluation result.

FIG. 3 shows a flowchart for adjusting the alarm output timing. First, it is determined based on a signal from the brake 12 whether or not the brake has been operated (S101). When the current inter-vehicle distance is dangerous, the driver operates the brake to decelerate. In this case, the current vehicle speed v is further reduced to a predetermined lower limit v ₀ (for example, 5
0 km / h) is determined using the vehicle speed signal from the vehicle speed sensor 11 and the lower limit value v ₀ stored in the ROM 14b in advance (S102). If the current vehicle speed v is the lower limit value v ₀ (e.g., 50 km / h), the inter-vehicle distance L _B at this time is detected by the inter-vehicle distance sensor 10, it is stored in the RAM 14 c.

[0014] Then, the inter-vehicle distance L _B is previously predetermined vehicle speed width Δ
v (for example, 5 km / h), sampling is performed until the number of inter-vehicle distance data in each vehicle speed section exceeds a predetermined value N ₀ (for example, 10), and these inter-vehicle distances are sampled. mean values m _n and the standard deviation sigma _n data calculated by CPU 14a (S105).
FIG. 4 shows sections [v ₀ , v ₀ + Δv], [v ₀ + Δv, v
_{0 + 2Δv], [v 0} + 2Δv, v 0 + An example of the average value m _n of inter-vehicle distance L _B in the three sections of 3Derutav] is shown. As described above, the average value _mn in each vehicle speed section represents the average value of the ten inter-vehicle distance data during the brake operation in that section. The average value _mn of the inter-vehicle distance is gradually increasing with the increase in the vehicle speed. Generally, when the vehicle speed increases, the driver tends to increase the inter-vehicle distance with the preceding vehicle in accordance with the vehicle speed. Therefore, it is based on the fact that the inter-vehicle distance at the time of the brake operation is also generally large.

[0015] Thus, after the average value m _n and the standard deviation sigma _n of inter-vehicle distance in each speed interval is calculated, and stored in RAM14c every vehicle speed intervals (S106), the average value m
_The driver's consciousness level is evaluated using _n and the standard deviation σ _n . That is, when the number of data in each speed interval reaches a predetermined value, that is, after the average value m _n and the standard deviation sigma _n in each speed interval is calculated all the current inter-vehicle distance L _B during braking operation, the vehicle speed zone mean values m _n belonging to consciousness level of the driver in accordance with the following evaluation formula using the standard deviation sigma _n belonging to the vehicle speed interval is evaluated.

D _n = | (L _B −m _n ) / σ _n | When the driver's consciousness level decreases, the average value _mn in each vehicle speed section and the inter-vehicle distance L _B at the time when the brake is operated are determined. Differences arise, and the differences increase as the level of consciousness decreases. Therefore, dn shows a larger value as the driver's consciousness level decreases. Conversely, dn approaches 0 when the driver's consciousness level is higher, that is, when the consciousness level is during normal driving. Thus, objectively can be evaluated (normal from the time of operation displacement indicates what times the standard deviation) consciousness level of the driver by the evaluation value d _n.

After evaluating the driver's consciousness level, the output timing of the warning signal is adjusted in order to set the warning on the safe side using this consciousness level (S1).
08). As a method of adjusting the output timing, as described above, in the present embodiment, the safety inter-vehicle distance is calculated, and an alarm signal is output based on the magnitude comparison with the safe inter-vehicle distance. by changing by the evaluation value d _n, and it is possible to adjust the output timing. Specifically, for example, when the calculated a safe distance to the Ds, new safe inter-vehicle distance G · d _n · D
By setting s (G: predetermined gain), the output timing can be adjusted to a safe side. That is, when the level of consciousness is decreased, the evaluation value d _n is large as described above, therefore, since the possible increases with the also reduced level of consciousness safe distance, and more early warning than normal during operation Will be emitted.

[0018] Thus, in the present embodiment, the evaluation value d _n of consciousness level of the driver = | and adjusts the output timing of the warning as assessed _{by, | (L B -m n)} σ n An alarm can be generated according to the driver's consciousness level, and safer traveling can be guaranteed.

In the present embodiment, the driver's consciousness level is evaluated by the above-described formula. However, the driver's consciousness level may be evaluated by using another calculation formula using the average value and the standard deviation. It is possible.

[0020]

As described above, according to the vehicular alarm system of the present invention, a warning is issued when the inter-vehicle distance from the preceding vehicle is less than the safe inter-vehicle distance. Since the warning is generated in consideration of the level, the warning can be more reliably generated, and there is an effect that extremely high safe driving can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of the present invention.

FIG. 2 is a configuration block diagram of one embodiment of the present invention.

FIG. 3 is an operation flowchart of the embodiment.

FIG. 4 is an explanatory diagram of an average value for each vehicle speed section in the embodiment.

[Explanation of symbols]

 Reference Signs List 10 inter-vehicle distance sensor 11 vehicle speed sensor 12 brake 13 bus 14 microcomputer 15 input / output port 16 alarm

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI G01S 17/88 A (58) Field surveyed (Int.Cl. ⁷ , DB name) B60R 21/00 G08G 1/00-9 / 02

Claims (1)

(57) [Claims] An inter-vehicle distance detecting means for detecting an inter-vehicle distance from a preceding vehicle; an arithmetic means for outputting an alarm signal based on a magnitude comparison between the inter-vehicle distance and a predetermined value according to the vehicle speed; Alarm means for generating an alarm based on the alarm signal from the arithmetic means, comprising: an alarm device for the vehicle, comprising: an average value and a standard deviation of the inter- vehicle distance during brake operation and the inter-vehicle distance during normal operation in the same vehicle speed section. An alarm device for a vehicle, comprising: an evaluation unit that evaluates a driver's consciousness level based on the evaluation unit; and an adjustment unit that adjusts an output timing of an alarm signal from the arithmetic unit in accordance with an evaluation result by the evaluation unit. .