JPH1166496A - Headway alarming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve collision preventing performance by continually outputting an inter-vehicle distance alarm when a distance between two vehicles is still reduced in spite of operating a brake when an inter-vehicle distance alarm is outputted. SOLUTION: At this alarming device, inter-vehicle distance detecting means 11 and 14 detect a distance between with a preceding vehicle and an arithmetic means 15 calculates a reference inter-vehicle distance from the speed of its own vehicle and the distance between vehicles, compares the reference inter- vehicle distance and an actual inter-vehicle distance and gives alarm outputting judgement when the inter-vehicle distance is short. Then at the time of the judging an inter-vehicle distance alarming output, a first alarming means 18 outputs a first inter-vehicle distance alarm and a second alarming means 19 operates at the time of detecting the braking operation of its own vehicle during judging the inter-vehicle distance alarming output and outputs a second inter- vehicle distance alarm varying an outputting mode according to the distance between vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward warning device which monitors a distance between a vehicle and a preceding vehicle and outputs a warning when the vehicle approaches a safe distance or less to alert a driver.

[0002]

2. Description of the Related Art Conventionally, an inter-vehicle distance from a preceding vehicle has been monitored,
2. Description of the Related Art Scanning laser radar devices and radio wave radar devices are known as forward warning devices that output an inter-vehicle distance alarm to alert a driver when the vehicle approaches a safe inter-vehicle distance or less. FIG. 5 shows such a conventional forward warning device, and FIG.
Shows a timing chart of the operation. In this conventional forward warning device, information on a forward object detected by a forward sensor 1 is calculated by a forward object detection device 2, and the calculation result of the forward object detection device 2 and the own vehicle speed from a vehicle speed sensor 3 are calculated. The data is input to the device 4, where the inter-vehicle distance to the preceding vehicle, the relative speed, and the relative speed due to a change in the inter-vehicle distance in unit time are calculated.

[0003] The arithmetic unit 4 further calculates the alarm distance at which an alarm is issued when the vehicle approaches the vehicle or less using parameters such as the own vehicle speed and the relative speed in consideration of the risk of a collision between the own vehicle and the preceding vehicle. When the measured inter-vehicle distance between the preceding vehicle and the own vehicle is equal to or shorter than the warning distance, the warning flag is output. The AND circuit 5 outputs the result to the alarm device 8 based on the AND logic of the result obtained by inverting the output of the brake switch 6 that is turned on when the brake is operated by the inverter 7 and the alarm flag from the arithmetic device 4, 8 is AN
An alarm device 8 such as a buzzer sound or a warning lamp for cautioning the following distance is operated by the output from the D circuit 5.

In such a conventional forward warning device, FIG.
As shown in, as long as the inter-vehicle distance is less than the alarm distance and the safe inter-vehicle distance required to avoid a rear-end collision can no longer be maintained, the alarm flag is set, and unless the brake is depressed and the brake switch 6 is turned on, The alarm device 8 is operated to issue an inter-vehicle distance alarm to the driver. Then, if the driver recognizes this inter-vehicle distance warning and operates the brake,
When the brake switch 6 is turned on and it is determined that the driver has performed an operation for avoiding a rear-end collision, the AND circuit 5 stops outputting the alarm command and cancels the alarm operation.

[0005]

However, such a conventional forward warning device has the following problems. As described above, when the inter-vehicle distance alarm is being output, the driver stops the alarm output when the driver operates the brake, so the driver determines that a safe inter-vehicle distance has been secured to prevent a collision by stopping the alarm. Brake operation may be interrupted, but especially when the preceding vehicle is suddenly braking, the brake operation is not sufficient if you do not pay close attention to the front and rely only on the judgment of the following distance warning Therefore, a situation may occur in which the inter-vehicle distance is rapidly reduced even though the inter-vehicle distance warning is stopped.

The present invention has been made in view of such a conventional problem. An inter-vehicle distance alarm is output, inter-vehicle distance monitoring is continued even after a brake operation is performed, and if the inter-vehicle distance tends to be reduced, a second inter-vehicle distance is monitored. It is an object of the present invention to provide a forward warning device which can output a warning of an inter-vehicle distance to warn a driver to take a safe inter-vehicle distance.

[0007]

According to a first aspect of the present invention, there is provided a forward warning device for detecting an inter-vehicle distance from a preceding vehicle, a relative speed based on a temporal change of the own vehicle speed and the inter-vehicle distance. Calculating a reference inter-vehicle distance from the vehicle, comparing the reference inter-vehicle distance with the inter-vehicle distance, determining an alarm output when the inter-vehicle distance is short, and outputting a first alarm when the alarm output is determined; Alarm means for outputting a second alarm when the own vehicle brake operation is detected while outputting the first alarm, wherein the alarm means changes the output mode of the second alarm according to the magnitude of the inter-vehicle distance. It is intended to be.

In the forward warning device according to the first aspect of the present invention, the inter-vehicle distance detecting means detects the inter-vehicle distance from the preceding vehicle, and the calculating means calculates the reference inter-vehicle distance from the own vehicle speed and a relative speed based on a temporal change in the inter-vehicle distance. Is calculated, and the reference inter-vehicle distance is compared with the actually measured inter-vehicle distance. When the inter-vehicle distance is short, an alarm output is determined. When the inter-vehicle distance alarm output is determined, the alarm unit outputs the first inter-vehicle distance alarm, and further detects the own vehicle brake operation while outputting the first inter-vehicle distance alarm.
A second inter-vehicle distance alarm, the output mode of which changes according to the inter-vehicle distance, is output.

As a result, the first inter-vehicle distance alarm is output, the approach of the inter-vehicle distance is monitored even after the driver operates the brake, and if the inter-vehicle distance is further reduced, the output mode is set according to the magnitude of the inter-vehicle distance. A second inter-vehicle distance warning in which the vehicle speed changes changes to prompt the driver to pay attention to the inter-vehicle distance, and to always maintain the safe inter-vehicle distance.

According to a second aspect of the present invention, there is provided the forward warning device according to the first aspect, wherein the first warning means outputs the first warning, and the second warning outputs the second warning. Means for outputting a first warning by the first warning means, and when detecting the own vehicle braking operation during the determination of the following distance warning, the second warning means responds to the magnitude of the following distance. And outputs a second alarm whose output mode changes.

According to a third aspect of the present invention, in the forward warning device according to the first or second aspect, the second warning is such that an output cycle or an output signal frequency becomes shorter as the inter-vehicle distance becomes shorter. It is.

According to a fourth aspect of the present invention, in the forward warning device according to any of the first to third aspects, the output level increases as the inter-vehicle distance decreases as the second warning.

In the forward warning device according to the third or fourth aspect of the present invention, when the brake operation is performed while the first warning is output due to the short distance between the vehicles, the warning means becomes smaller as the distance between the vehicles becomes shorter. A second alarm in which the output cycle or the output signal frequency is shortened is output, or a second alarm in which the output level is increased is output.

[0014]

As described above, according to the first and second aspects of the present invention, the first inter-vehicle distance warning is output, the approach of the inter-vehicle distance is monitored even after the driver operates the brake, and the inter-vehicle distance is further reduced. If this is the case, a second inter-vehicle distance alarm whose output mode changes in accordance with the magnitude of the inter-vehicle distance is output to prompt the driver to pay attention to the inter-vehicle distance, and to always maintain the safe inter-vehicle distance.

According to the third aspect of the present invention, when the brake operation is performed while the inter-vehicle distance is approaching and the alarm means is outputting the first alarm, the alarm means outputs as the inter-vehicle distance becomes shorter. A second alarm in which the cycle or the output signal frequency is shortened is output, and the driver can be warned by outputting an alarm in a more tense manner as the inter-vehicle distance becomes shorter.

According to the fourth aspect of the present invention, if the brake operation is performed while the inter-vehicle distance is approaching and the alarm means is outputting the first alarm, the alarm means outputs as the inter-vehicle distance becomes shorter. The second alarm that increases the level is output, and the driver can be warned by outputting an alarm in a more tense manner as the inter-vehicle distance becomes shorter.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration of a first embodiment of the present invention. A forward warning device according to the first embodiment emits a laser or a radio wave forward and reflects back to a preceding vehicle. A front sensor 11 that receives light, converts it into an electric signal, and outputs it, and a vehicle speed sensor 12 that detects the vehicle speed
And a brake switch 13 for outputting an ON signal when a brake is operated is provided as external signal input means. For the front sensor 11, a scanning laser radar device or a radio wave radar device is used.

The forward warning device further includes a forward object detection device 14 for calculating coordinate information of the forward object based on a reflected light reception signal of the forward sensor 11 and a vehicle speed input from the vehicle speed sensor 12 to obtain the forward object detection device 14. Enter the coordinate information of the object ahead, calculate the inter-vehicle distance with the preceding vehicle, the relative speed, the warning distance as a reference distance between vehicles that is safe to avoid rear-end collision, and compare the inter-vehicle distance with the warning distance A calculating device for determining whether or not to output the inter-vehicle distance approach warning and outputting a warning 1 flag and a warning 2 flag according to the input state of the brake switch 13; and a first device for driving the first warning device. An alarm generator (1) 16 and a second alarm generator (2) 17 for driving a second alarm device are provided.

The alarm 1 flag output by the arithmetic unit 15 is
This flag is set when the vehicle approaches the preceding vehicle suddenly, and if the vehicle approaches the preceding vehicle quickly, the rear-to-back distance becomes so high that there is a strong risk of collision. The alarm 2 flag is a flag that is set when a brake operation is performed while the alarm 1 flag is set.

The forward warning device further includes a first warning device (1) 18 for outputting a first warning when the inter-vehicle distance is short and the warning 1 flag is output, and a first warning device (1) for outputting the first warning when the warning 2 flag is output. A second alarm device (2) 19 for outputting a second alarm is provided as alarm output means.

Next, the operation of the forward warning device having the above configuration will be described with reference to FIGS. The front sensor 11 periodically emits a laser or radio wave signal forward, receives a reflected signal that is reflected back from a front object, and outputs the received signal to the front object detection device 14. Forward object detection device 1
Reference numeral 4 analyzes the reception signal of the front sensor 11, calculates coordinate information of the preceding vehicle from among the front objects, and outputs the result to the arithmetic unit 15.

The arithmetic unit 15 calculates the following distance, the relative speed, and the warning distance from the preceding vehicle based on the coordinate information of the front object calculated by the front object detecting device 14 and the own vehicle speed from the vehicle speed sensor 12. By comparing the inter-vehicle distance with the alarm distance, if the actual inter-vehicle distance is closer than the alarm distance, FIG.
As shown in (a), an alarm 1 flag is output. Also, as shown in FIGS. 3B and 3C, when a brake signal is input from the brake switch 13 while the alarm 1 flag is being output, the alarm 1 flag is output while the brake signal is being input. Is stopped and the alarm 2 flag is output instead.

When the alarm 1 flag is set, the first alarm generator (1) 16 outputs an alarm drive signal, and the first alarm device (1) 18 outputs a first alarm. For this first warning, a warning buzzer is used together with the lighting of the following distance warning lamp.

With this first alarm, the driver recognizes the approach of the inter-vehicle distance and operates the brake to operate the brake switch 1.
When 3 is turned on, the arithmetic unit 15 clears the alarm 1 flag and sets the alarm 2 flag. The operation of the first alarm device (1) 18 is stopped by clearing the alarm 1 flag. Then, by setting the alarm 2 flag, the second alarm generator (2) 17 outputs a drive signal, and the second alarm device (2) 19 performs an alarm output operation. The alarm output operation of the second alarm device (2) 19 will be described later.

Thereafter, when the driver releases the brake and the brake switch 13 is turned off, the alarm 2 flag is cleared. If the inter-vehicle distance is closer than the alarm distance at this moment, the arithmetic unit 15 outputs the alarm 1 The flag is set again, the first alarm device (1) is operated to output an inter-vehicle distance alarm, and the driver is notified that a brake operation is necessary. If the brake operation is sufficiently performed and the inter-vehicle distance is greater than the warning distance, the arithmetic unit 15 does not reset the warning 1 flag when the brake is released, and therefore, the first warning device (1) 18 operates again. Never.

Thus, if the actual inter-vehicle distance is closer than the warning distance, a warning is output by the first warning device (1) 18 when the brake operation is not performed. An alarm is output by the second alarm device (2) 19 until the inter-vehicle distance becomes longer than the inter-vehicle distance, and the driver can be alerted to the inter-vehicle distance.

Next, a description will be given of how the second alarm device (2) 19 changes the output mode according to the distance between the vehicles. As shown in FIGS. 3A and 3C, when the alarm 1 flag is set and the brake switch 13 is turned off, the first alarm generator (1) 16 outputs a drive signal of a predetermined level at a predetermined cycle. Accordingly, the first alarm device (1) 18 outputs an alarm of a constant output level at a constant period.

On the other hand, FIGS. 3 (b), (d) to (f)
While the brake switch 13 is turned on and the alarm 2 flag is set, the second alarm generator (2) 17 outputs a drive signal for changing the operating frequency depending on the actual distance between vehicles as shown in FIG. In response to this, the second alarm device (2) 19 also outputs an alarm whose output cycle changes in accordance with the change in the following distance. In the example of FIG. 3, an alarm drive signal whose output cycle becomes faster as the inter-vehicle distance becomes shorter is output. For example, at first, “Poo, Poo,
"...", the cycle is accelerated to "Poo, Poo, Poo, ...", and when approached further, the cycle is further advanced to "Poo, Poo, Poo, Poo, ...", and when approached further, the continuous sound " It changes in such a way that it changes to a sound like "-----".

As a result, the driver recognizes the first warning (1) of approaching the inter-vehicle distance and performs the brake operation. However, if the inter-vehicle distance is still small, the second variable which varies according to the inter-vehicle distance. By receiving the warning (2), it is possible to recognize that more urgent attention is required for the following distance, and to further maintain the safe following distance.

In the above-described embodiment, the case where the inter-vehicle distance warning is notified by sound has been described. However, the inter-vehicle distance warning lamp which is lit at a position recognizable by the driver's line of sight together with the sound warning is installed. In addition, it is possible to adopt a configuration in which the blinking cycle of the lamp changes according to the inter-vehicle distance together with the second alarm sound.

Further, in the inter-vehicle distance warning using the sound and the warning lamp, not only the output cycle is changed in accordance with the inter-vehicle distance, but also an embodiment in which the output frequency is changed together with or instead of the output cycle can be adopted. . In this case, particularly in the case of a warning sound, the driver needs to take more urgent attention to the following distance by changing from a relatively low-tone warning sound to a high-pitched warning sound that gives a sense of urgency as the following distance approaches. You will be able to recognize that.

Further, the second alarm generating circuit (2) 17 may be configured to operate as shown in FIG. That is, as shown in FIGS. 7A and 7C, when the alarm 1 flag is set and the brake switch 13 is turned off, the first alarm generator (1) 16 is driven at a predetermined period and at a predetermined level by the drive signal. And the first alarm device (1) 1
Numeral 8 outputs a constant period, constant output level alarm.

However, FIG.
As shown in (2), while the brake switch 13 is on and the alarm 2 flag is set, the second alarm generator (2) 17 outputs a drive signal for changing the output level depending on the actual distance between the vehicles. In response, the second alarm device (2) 19 also outputs an alarm in which the output level changes depending on the change in the following distance. In the example of FIG.
The output level increases as the inter-vehicle distance approaches, and the output level is changed so as to output a larger alarm sound.

As a result, the driver recognizes the first warning (1) of approaching the inter-vehicle distance and performs the brake operation. However, if the inter-vehicle distance is still short, a loud sound is generated according to the inter-vehicle distance. By listening to the change in the warning sound of No. 2, it becomes possible to recognize that more urgent attention is required for the following distance, and to further maintain the safe following distance.

It should be noted that the present invention is not limited to these embodiments. As a change mode corresponding to the change in the inter-vehicle distance of the second alarm, the output cycle and the output level can be changed simultaneously,
A combination that simultaneously changes the output signal frequency and the output level is also possible.

In the embodiment of FIG. 1, (1) and (2)
Although the above-mentioned alarm device is shown as a separate device, this may be configured as one common device so as to output both the first alarm and the second alarm.

As described above, according to the forward warning device of the present invention, in the case where the following distance is approached and the following distance is still approached even after the driver operates the brake, not only is the inter-vehicle distance warning output, The shorter the inter-vehicle distance, the faster the output cycle of the alarm, the higher the frequency of the output signal, and the higher the output level, so that the driver can better recognize the urgent need for collision avoidance operation for approaching the inter-vehicle distance. And safe driving performance for maintaining the following distance is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a timing chart showing an output operation of an inter-vehicle distance warning according to the embodiment.

FIG. 3 is a timing chart showing an example of an output operation of an alarm drive signal of a second alarm generation circuit (2) in the embodiment.

FIG. 4 is a timing chart showing another example of the output operation of the alarm drive signal of the second alarm generation circuit (2) in the above embodiment.

FIG. 5 is a block diagram of a conventional example.

FIG. 6 is a timing chart showing an output operation of an inter-vehicle distance warning according to a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 front sensor 12 vehicle speed sensor 13 brake switch 14 front object detection device 15 arithmetic device 16 first alarm generator (1) 17 second alarm generator (2) 18 first alarm device (1) 19 second Alarm device (2)

Claims (4)

[Claims] An inter-vehicle distance detecting means for detecting an inter-vehicle distance from a preceding vehicle, a reference inter-vehicle distance is calculated from a vehicle speed and a relative speed based on a temporal change in the inter-vehicle distance, and the reference inter-vehicle distance and the inter-vehicle distance are calculated. Calculating a warning output when the inter-vehicle distance is short, and outputting a first warning when the warning output is determined, and detecting a vehicle brake operation while outputting the first warning. Alarm means for outputting a second alarm, wherein the alarm means is configured to output the second alarm in accordance with the distance between the vehicles.
A forward warning device, wherein the output mode of the warning is changed. 2. The alarm unit includes: a first alarm unit that outputs the first alarm; and a second alarm unit that outputs the second alarm.
2. The forward alarm device according to claim 1, further comprising: an alarm unit. 3. The forward warning device according to claim 1, wherein the second warning shortens the output cycle or the output signal frequency as the inter-vehicle distance becomes shorter. 4. The forward warning device according to claim 1, wherein the second warning increases the output level as the inter-vehicle distance decreases.