JPH092152A - Alarm device - Google Patents

Abstract

PURPOSE: To generate an alarm sound which is always easy for a driver to hear in such a situation that various interior is present. CONSTITUTION: An alarm device is to sound an alarm by predicting the possibility of a deviation from a lane or the like from image data obtained by a CCD camera 11. The alarm device comprises a microphone 17 to collect interior noise; an alarm sound generating means 18 to detect a frequency band of the low sound pressure level of interior noise and generate an alarm sound within the frequency band; and an alarm 16 to emit an alarm sound according to the output of the alarm sound generating means when the possibility of a deviation from a lane is predicted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ADA system (Active Drive Assist S) that assists a driver's driving operation.
For vehicles equipped with ystem), an alarm device that issues a warning by predicting the possibility of lane departure, etc. from the image data obtained by the front monitoring camera. Regarding

[0002]

2. Description of the Related Art In recent years, in order to drastically improve the safety of vehicles against the increasing tendency of traffic accidents, that is, preventive safety so as not to fall into a dangerous state from the beginning, the driving operation is actively assisted. A comprehensive driving support system, a so-called ADA system (Active Drive Assist system) has been developed. This ADA system recognizes road conditions, white lines, traffic environment, etc. from image data of a front monitoring camera mounted on a vehicle, and the vehicle is used when the driver is driving with a decreased awakening level due to a drowsiness, etc. Predict the possibility of lane departure, rear-end collision, etc. Then, as a way of providing driving assistance when predicting a lane departure, etc., based on the idea that a vehicle is operated by a human being, a warning is first issued to prompt the driver to perform an avoidance operation. If the driver does not perform appropriate avoidance operation even if an alarm is issued, it is suggested to automatically control the driving operation system of the brake, throttle, or steering to the safe side, or assist the driver to temporarily perform the driving operation. Has been done.

Therefore, the alarm device of the ADA system is very important for allowing the driver to take a risk avoidance action by himself. For this reason, it is necessary for the alarm to appropriately notify the driver or the vehicle in various situations without causing discomfort to the driver.

Here, as an alarm means, it is advantageous that an alarm sound can be given aurally even when the driver's eyes are resting or facing sideways. However, since various vehicle interior sounds such as noise inside and outside the vehicle and audio sounds exist in the vehicle interior of a vehicle such as a traveling automobile, the alarm sound is inevitably affected by the vehicle interior sound. Further, the sound inside the vehicle changes each time under various conditions such as traveling speed, opening and closing of windows, condition of road surface and tires, audio content and volume. Therefore, the warning sound is required to appropriately notify the driver of the above-mentioned vehicle interior sound.

Conventionally, as for the above-mentioned alarm device, for example, there is a first prior art of Japanese Utility Model Laid-Open No. 61-90653.
It has been shown that in an alarm device that emits an alarm sound when an abnormality of a vehicle body is detected by various sensors, a noise sensor detects noise in the vehicle interior, and when the noise becomes high, the volume of the alarm sound is increased. In addition, automobile technology casebook, issue number 9
In the second prior art of 2178, in a collision prevention warning device using a laser radar, it is shown that the volume of the audio is reduced when the power of the audio is turned on when the warning sound is generated.

[0006]

By the way, in the above-mentioned first prior art, the volume of the alarm sound is increased according to the noise in the passenger compartment, so that it is unnecessarily high when the window is opened. An audible alarm sounds, which gives the driver an unpleasant feeling. In addition, the driver may be surprised by a sudden large alarm and make a mistake. Further, in the second prior art, the volume of the audio is reduced when the alarm sound is generated. Therefore, when the outside sound of the vehicle is large due to the opening of the window or the like, the alarm is generated even if the volume of the audio is reduced. You may not hear the sound. In addition, audio requires additional means for changing the volume in response to a signal from an alarm device, resulting in high cost and reduced versatility.

In view of the above points, the present invention has an object to generate a warning sound in a state where various in-vehicle sounds exist so that the driver can always easily hear the warning sound.

[0008]

In order to achieve this object, an alarm device according to claim 1 of the present invention issues an alarm by predicting the possibility of a lane departure or the like based on image data obtained by a front monitoring camera. The microphone that emits the sound inside the vehicle and the frequency band of the low sound pressure level of the sound inside the vehicle are detected.
An alarm sound generating means for generating an alarm sound in the frequency band;
An alarm device that emits an alarm sound according to the output of the alarm sound generation means when predicting the possibility of lane departure or the like is provided.

In the alarm device according to a second aspect of the present invention, the alarm sound generating means measures the in-vehicle sound volume by means of a microphone, and when the in-vehicle sound volume is equal to or higher than a predetermined value, the in-vehicle sound is frequency-analyzed to obtain the minimum sound pressure. Minimum sound pressure level frequency band detecting means for detecting the frequency band of the level, alarm volume setting means for setting the alarm sound volume according to the in-vehicle sound volume and the minimum sound pressure level, and the minimum sound when predicting the possibility of lane departure etc. It is characterized by comprising a driving means for outputting an alarm signal of a frequency of the pressure level frequency band and a predetermined alarm volume to an alarm device.

[0010]

Therefore, according to the first aspect of the present invention, while the driver is driving the vehicle, the front monitoring camera captures an image of the scenery, objects and the like in front of the vehicle. It is determined whether or not. Further, the sound inside the vehicle is collected by the microphone, the low-sound pressure level frequency band of the sound inside the vehicle is detected by the alarm sound generating means, and the alarm sound within the frequency band is generated. Therefore, when the window is opened even if the volume inside the vehicle is large, or in each situation where the audio sound is loud, a frequency band that is hardly included in the vehicle interior sound is detected. It becomes possible to hear.

When the driver's awakening level is lowered due to drowsiness or the like, and the possibility of lane departure or the like is predicted, an alarm sound of a frequency in this frequency band is generated by an alarm device. Therefore, the driver can clearly hear the alarm sound without being surprised or uncomfortable even if the alarm sound is low in a situation where the volume inside the vehicle is high, and accordingly, the possibility of a lane departure or the like is appropriately notified. To be done.

In the second aspect, the in-vehicle sound volume is measured by the in-vehicle sound volume measuring means. When the volume of the vehicle interior is equal to or higher than a predetermined value and it is difficult to hear the alarm sound, the minimum sound pressure level frequency band detection means performs a frequency analysis of the vehicle interior sound to detect the frequency band of the minimum sound pressure level. When the value is large, the frequency band not included in the vehicle interior sound is accurately detected.

Further, the alarm volume setting means sets the alarm volume to a value that can be heard even if it is low, depending on the volume in the vehicle and the minimum sound pressure level. And when predicting the possibility of lane departure etc.,
An alarm signal is output from the drive means to the alarm device, and an alarm sound having a predetermined alarm volume at a frequency in the minimum sound pressure level frequency band is generated. Therefore, the driver can clearly hear the alarm sound without being surprised or uncomfortable when the volume in the vehicle is high.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. An example of the ADA system and the alarm device will be described with reference to FIG. In the ADA system 10, two CCD cameras 11 are provided as front monitoring cameras on the ceiling in the passenger compartment 2 of the vehicle 1, and the image signals of these CCD cameras 11 are input to the image recognition means 12.

The two CCD cameras 11 stereoscopically capture and capture the landscape and objects in front of the vehicle. The image recognition means 12 processes the image signals picked up by the two CCD cameras 11 by the triangulation method based on the stereo method to calculate the distance, and creates a distance image having a three-dimensional distance distribution over the entire screen. Then, lanes, preceding vehicles, obstacles, etc. are separated and detected from the distance image, and the left and right white lines, the three-dimensional shape of the road, etc. are recognized from the lanes. Further, it recognizes what the front object is, the relative distance to the preceding vehicle and obstacles, the speed, etc., and thus obtains the image data of the road and the traffic environment.

The image data of the image recognizing means 12 is inputted to the lane departure determining means 13 to determine the possibility of lane departure on the left and right sides of the vehicle. When predicting the deviation of the vehicle from the traveling lane, for example, the positions YL and YR of the white lines H1 and H2 on the left and right of the traveling lane (YL and YR are positive on the right side and negative on the left side with respect to the center line of the vehicle). Is measured, and the road width D between the lanes is calculated by D = YR-YL. Further, the position Y of the vehicle with respect to the lane center line O is Y = (D / 2) −YR =
It is calculated by − (YR + YL) / 2. Then, depending on the maximum width W of the vehicle, the position Y, and the road width D between the lanes, Y ≧ 0 and Y +
When (W / 2) ≧ D / 2, the lane departure on the right side is determined, and the degree of possibility is determined based on the magnitude relationship of the values. When Y <0 and -Y- (W / 2) <-D / 2, the lane departure on the left side is determined, and the degree of possibility is similarly determined based on the magnitude relationship of the values.

The inter-vehicle distance L between the host vehicle 1 and the preceding vehicle M1
1. The possibility of a rear-end collision is determined by the following formula based on the host vehicle speed V, the preceding vehicle speed V1, the set acceleration / deceleration rate α of the host vehicle 1, the set acceleration / deceleration rate α1 of the preceding vehicle M1, and the set time T1 for allowing a margin. To do. L1 ≦ (−V1 ² / 2α1) + {(V ² / 2α) + V · T1} Then, when the possibility of the lane departure or the rear-end collision is predicted, the warning device 15 is instructed to give a warning.

The alarm device 15 is provided with an alarm device 16 for generating an alarm sound such as a speaker in the passenger compartment 2. Also in the passenger compartment 2
For example, a microphone 17 is provided on the ceiling inside the microphone 1.
The voice signal 7 is input to the alarm sound generating means 18. The microphone 17 collects an in-vehicle sound that changes according to various conditions such as traveling speed, opening and closing of windows, condition of road surface and tires, audio content and volume in the cabin 2 of the vehicle 1 such as a traveling automobile. .

The alarm sound generating means 18 has an in-vehicle sound volume measuring means 20, measures the overall in-vehicle sound volume of the in-vehicle sound collected by the microphone 17, and inputs this in-vehicle sound volume to the frequency and sound volume determining means 21. . The frequency / volume determination means 21 determines the volume of the volume in the vehicle, and in a relatively quiet indoor environment below a predetermined value, any alarm sound can be easily heard by the driver. Vo
And the alarm signal is input to the driving means 22. When it is difficult to hear the alarm sound in a noisy indoor environment where the volume inside the vehicle is equal to or higher than a predetermined value, the alarm frequency fs and the volume Vs are separately set as follows.

That is, it has a minimum sound pressure level frequency band detecting means 23 for inputting the in-vehicle sound of the microphone 17, and analyzes the frequency and sound pressure level of the in-vehicle sound as shown in FIG. 2 to determine the minimum sound pressure level as the minimum sound. The frequency band Df of the pressure level is detected.
Therefore, in each of the situations where the window is opened and the volume of the vehicle interior is high, and the volume of the audio is large, the frequency band Df that is hardly included in the vehicle interior sound is selected. Can be heard.

Here, even the alarm sound in the frequency band Df of the minimum sound pressure level may not be fully heard if the volume is insufficient. For this reason, the alarm volume setting means 24 is provided, and the alarm volume Vs is set to a value higher than at least the minimum sound pressure level according to the volume in the vehicle and the minimum sound pressure level. It will be possible to reliably hear. Frequency band D of these minimum sound pressure levels
The frequency f and the alarm volume Vs are input to the volume determining means 21, the predetermined frequency fs of the frequency band Df of the minimum sound pressure level is selected as the alarm frequency, and the amplification coefficient α corresponding to the alarm volume Vs is selected as the volume. Is calculated and this alarm signal is input to the driving means 22.

The drive means 22 drives the alarm device 16 in accordance with the volume of the vehicle interior volume when an alarm is issued by predicting the possibility of a lane departure or the like. That is, when the in-vehicle volume is low, the alarm sound is emitted at a predetermined frequency fo and a voltage corresponding to the volume Vo is applied to the alarm device 16 to generate an alarm sound of the frequency fo and the volume Vo. Further, when the volume in the vehicle is large, the alarm sound with the frequency fs and the volume Vs is generated by transmitting the voltage fs of the minimum sound pressure level for alarm and applying the voltage amplified by the amplification coefficient α to the alarm device 16. Is configured as follows.

Next, the alarm control will be described with reference to the flowchart of FIG. First, when the driver A operates the vehicle to travel, the image is recognized by the image signal from the CCD camera 11 (step S1), and the vehicle may deviate from the lane or collide with the vehicle based on the image data. It is determined whether or not (step S2). Then, when the driver A normally drives and there is no possibility of lane departure or the like, the process directly returns.

On the other hand, when the driver A is likely to fall awake due to a drowsiness or the like and deviates from the lane, the sound volume in the vehicle is measured (step S3), and it is determined whether the sound volume in the vehicle is a predetermined value or more. It is determined (step S4). In a quiet indoor environment below a predetermined value, a predetermined frequency fo and a volume Vo
Is set (step S5), and the alarm device 16 is activated under this condition to generate a small alarm sound as indicated by the alternate long and short dash line in FIG. 2 (step S10). Therefore, the driver A can hear the alarm sound without being surprised or uncomfortable, and the alarm sound is appropriately informed of the possibility of a lane departure or the like, and the driver can promptly take avoidance action.

In a noisy indoor environment where the window volume is open or the volume of the audio is too loud and the volume inside the vehicle is above a predetermined value,
Frequency analysis of in-vehicle sound by the microphone 17 (step S
6). Here, sounds below 100 Hz are very difficult to hear, and sounds above 1000 Hz are very annoying.
Sounds of 100 to 1000 Hz are easy to hear and are suitable as alarm sounds. Therefore, the in-vehicle sound is analyzed at 1/3 octave between 100 and 1000 Hz, with a center frequency of 500 Hz, for example. By this frequency analysis, there is always a frequency band of the minimum sound pressure level that is a band of sounds that is easy to hear, and the frequency band Df is easily detected (step S7). Therefore, a predetermined frequency fs in the frequency band Df is selected for alarm (step S8). Therefore, in a situation where the vehicle interior volume is high, the frequency fs that is easy to hear and is hardly included in the vehicle interior sound is selected.

Further, in this case, the amplification coefficient α of the alarm volume Vs corresponding to the in-vehicle volume and the minimum sound pressure level is calculated (step S9). Then, the alarm device 16 is operated under the conditions of the alarm frequency fs and the amplification coefficient α (step S
10) As a result, the alarm sound is generated with a low volume in the region of the minimum sound pressure level not included in the vehicle interior sound as shown by the solid line in FIG. Therefore, the driver A does not feel surprised or uncomfortable with the low volume Vs. Further, the driver A can clearly hear the sound of the frequency fs which is not included in the vehicle interior sound even if the vehicle interior volume is high. Then, the warning sound appropriately notifies the possibility of lane departure and the like, and in this case also, it becomes possible to promptly take avoidance action.

Although the embodiment of the present invention has been described above, the low sound pressure level is not limited to the minimum sound pressure level.

[0028]

As described above, in the alarm device according to the first aspect of the present invention, the microphone for collecting the in-vehicle sound and the frequency band of the low sound pressure level of the in-vehicle sound are detected and within the frequency band. The warning sound generating means for generating the warning sound and the warning device for generating the warning sound according to the output of the warning sound generating means when predicting the possibility of lane departure or the like are provided. In any of the above cases, an alarm sound in a frequency band that is hardly included in the vehicle interior is generated and can be heard clearly, and the alarm function is increased. Since the volume of the alarm sound is low, the driver is not surprised or uncomfortable.

In the alarm device according to the second aspect, the alarm sound generation means measures the in-vehicle sound volume by the microphone and the in-vehicle sound frequency-analyzes when the in-vehicle sound volume is equal to or higher than a predetermined value to obtain the minimum sound pressure. Minimum sound pressure level frequency band detecting means for detecting the frequency band of the level, alarm volume setting means for setting the alarm sound volume according to the in-vehicle sound volume and the minimum sound pressure level, and the minimum sound when predicting the possibility of lane departure etc. Since the driving means for outputting the frequency of the pressure level frequency band and the alarm signal of the alarm volume to the alarm device is provided, it is possible to appropriately generate the alarm sound of the frequency that is easy to hear when the volume in the vehicle is large. Further, the volume of the alarm sound is appropriately set, so that the alarm sound can be surely recognized.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a relationship between an in-vehicle sound and an alarm sound.

FIG. 3 is a flowchart of alarm control.

[Explanation of symbols]

 11 CCD camera (forward monitoring camera) 16 alarm device 17 microphone 18 alarm sound generating means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G08G 1/16 G08G 1/16 C

Claims (2)

[Claims] 1. An alarm device for predicting the possibility of a lane departure or the like based on image data obtained by a front monitoring camera and issuing an alarm, wherein a microphone for collecting vehicle interior sound and a frequency band of a low sound pressure level of vehicle interior sound are provided. And a warning device for generating a warning sound within the frequency band, and a warning device for issuing a warning sound according to the output of the warning sound generation means when predicting the possibility of lane departure or the like. Alarm device. 2. The alarm sound generating means detects an in-vehicle sound volume measuring means for measuring an in-vehicle sound volume by a microphone, and frequency-analyzes the in-vehicle sound to detect a frequency band of a minimum sound pressure level when the in-vehicle sound volume is a predetermined value or more. Minimum sound pressure level frequency band detection means, alarm sound volume setting means for setting an alarm sound volume in accordance with the in-vehicle sound volume and the minimum sound pressure level, and the frequency of the minimum sound pressure level frequency band when predicting the possibility of lane departure etc. The alarm device according to claim 1, further comprising a driving unit that outputs an alarm signal having a predetermined alarm volume to an alarm device.