JP2763684B2 - Emergency vehicle detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for driving an automobile, and more particularly to an emergency vehicle detection device for detecting the approach of an emergency vehicle from a siren sound of the emergency vehicle.

[0002]

2. Description of the Related Art Heretofore, a driver of an automobile has judged by ear that an emergency vehicle is approaching. For this reason, when listening at a high volume of a car stereo or the like, the driver may not notice the approach of the emergency vehicle and may cause an accident or other obstacles.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the siren sound of an emergency vehicle without being disturbed by the noise of the surrounding environment. An object of the present invention is to provide an emergency vehicle detection device for identifying and outputting an emergency vehicle recognition signal.

[0004]

An emergency vehicle detection device according to the present invention includes a microphone for picking up a siren sound of an emergency vehicle, and an emergency vehicle recognition unit for recognizing that an output signal of the microphone is an emergency vehicle siren sound. And a microphone control unit that controls the passage of the output signal of the microphone, and turns on and off the output circuit of the microphone at a constant cycle until the emergency vehicle recognition unit recognizes the siren sound of the emergency vehicle. When the siren sound of the emergency vehicle is recognized, it turns on for a certain period of time. When the same siren sound is recognized again, an emergency vehicle recognition signal is output. When the same siren sound is not recognized again, the output circuit of the microphone is turned on and off at a fixed cycle. It is configured to be in the original state.

In the emergency vehicle detection device, the emergency vehicle recognition signal is output when the same siren sound is recognized a plurality of times again.

Further, in each of the emergency vehicle detection devices, the period during which the output circuit of the microphone is turned on once the emergency vehicle recognition unit recognizes the siren sound of the emergency vehicle is determined according to the length of the initial siren sound. It is.

[0007]

[Function] If the microphone for picking up the siren sound of the emergency vehicle is always kept on, it often causes a malfunction when the surrounding noise is input. By turning on the microphone for a predetermined period after the siren sound of the emergency vehicle is detected, the siren sound of the emergency vehicle in which a fixed voice signal pattern continues is detected without malfunction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An emergency vehicle detection device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a microphone, and a plurality of microphones are arranged outside a vehicle. The output signals of the microphones 1, 1,... Are input to the preamplifier 2. The preamplifier 2 is turned on / off by a control signal output from a microphone control unit 4. When the control signal is on, the preamplifier 2 amplifies the output signals of the microphones 1, 1,. The emergency vehicle recognition unit 3 includes an analog processor 3a, a CPU 3b, a RAM 3c, a ROM 3d, and an interface 3e. The analog processor 3a also includes a filter bank and an A / D converter. The analog processor 3a passes only the component of the siren sound band of the emergency vehicle from the analog signal input from the preamplifier 2 and converts it into a digital signal. The CPU 3b compares the signal pattern from the analog processor 3a with the pattern of the siren sound of the emergency vehicle stored in the ROM 3d according to the program stored in the ROM 3d, and communicates with the microphone control unit 4 or an external alarm via the interface 3e. Output a signal. The microphone control unit 4 normally outputs a signal that repeats a fixed short on-period and an off-period. However, when receiving an emergency vehicle recognition signal from the emergency vehicle recognizing unit 3, it outputs an on-signal for a predetermined long period.

In the above configuration, the output of the microphone 1 is identified by the emergency vehicle recognizing unit 3 while repeating a fixed short on-period and off-period, so that malfunction due to noise is prevented. When the emergency vehicle recognition unit 3 confirms the siren sound of the emergency vehicle, a signal indicating the length of the siren sound is output to the microphone control unit 4, and the microphone control unit 4 is turned on according to the length of the siren sound. A period is determined and an ON signal is output to the preamplifier 2. The preamplifier 2 continuously amplifies the signal of the microphone 1 and outputs it to the emergency vehicle recognition unit 3 while the microphone control unit 4 outputs the ON signal. When the emergency vehicle recognition unit 3 recognizes the same siren sound a predetermined number of times, it outputs an emergency vehicle recognition signal to an external alarm device, and the alarm device notifies the driver of the approach of the emergency vehicle.

FIG. 2 is a block diagram showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes a microphone for picking up a siren sound of an emergency vehicle, which is arranged outside a vehicle. The output signal of the microphone 1 is input to the variable gain amplifier 5. The variable gain amplifier 5 includes a level control unit 6
The gain is controlled by a control signal output from the controller 1, and the output signal of the microphone 1 is amplified and output to the emergency vehicle recognition unit 3. The emergency vehicle recognition unit 3 compares the input signal pattern with the siren sound pattern of the emergency vehicle stored in the ROM, and outputs an emergency vehicle recognition signal to an external alarm when the input signal matches the siren sound pattern. .
Reference numeral 1a denotes a microphone for picking up environmental noise, which is arranged outside the vehicle. The output signal of the microphone 1a is input to the level control unit 6. The level control section 6 outputs a control signal according to the input noise level, and increases the gain of the variable gain amplifier 5 when the noise level is high, and decreases the gain of the variable gain amplifier 5 when the noise level is low.

In the above configuration, since the output of the microphone 1 is amplified to an appropriate level corresponding to the noise level and is identified by the emergency vehicle recognition unit 3, malfunction due to noise is prevented. When the emergency vehicle recognition unit 3 recognizes the same panning signal as the siren sound of the emergency vehicle, it outputs an emergency vehicle recognition signal to an external alarm device, and the alarm device notifies the driver of the approach of the emergency vehicle.

FIG. 3 is a block diagram showing a second embodiment of the present invention. In the figure, reference numeral 1 denotes a microphone for picking up a siren sound of an emergency vehicle, which is arranged outside a vehicle. The output signal of the microphone 1 is passed through the bandpass filter 7, 7a, 7b or 7c to the emergency vehicle recognition unit 3.
Is input to The bandpass filters 7, 7a, 7b and 7c are narrow-band filters adapted to the siren sound band of ambulances, fire trucks, police cars, etc., and block the passage of noise. The emergency vehicle recognition unit 3 converts the input signal pattern to RO
A comparison is made with the siren sound patterns of the various emergency vehicles stored in M, and a recognition signal for each type of emergency vehicle is output to an external alarm device.

In the above configuration, the siren sound of the ambulance, fire engine, police car, etc. input from the microphone 1 passes through the band-pass filter 7, 7a, 7b or 7c of the band, and is input to the emergency vehicle recognition unit. Blocking by a bandpass filter prevents malfunctions due to noise. When the emergency vehicle recognition unit 3 recognizes the same pan signal as the siren sound of the emergency vehicle, it outputs a recognition signal for each emergency vehicle type to an external alarm, and the alarm notifies the driver of the approach of the emergency vehicle.

FIG. 4 is a block diagram showing a third embodiment of the present invention. In the figure, reference numeral 1 denotes a microphone, and a plurality of microphones are arranged outside a vehicle. The output signal of the microphone 1 is input to the preamplifier 2. The preamplifier 2 amplifies the output signal of the microphone 1 and performs an emergency vehicle recognition unit 3
Output to The emergency vehicle recognition unit 3 sets the input signal pattern to R
When the input signal matches the siren sound pattern stored in the OM and matches the siren sound pattern, the input signal is output to the false recognition prevention unit 8. The erroneous recognition prevention unit 8 includes an interface 8a, a CPU 8b, and a RAM 8c.
The CPU 8b stores the first input signal pattern in the RAM 8c according to the program stored in the ROM 8d. RAM 8c
The memory is divided into blocks and has a pattern storage area for each type of emergency vehicle, and the CPU 8b stores an input signal pattern in each storage area according to an output signal from the emergency vehicle recognition unit 3. Once the input signal pattern is R
When stored in the AM 8c, the RAM 8c
Is compared with the stored pattern. When the same pattern is input a predetermined number of times, an emergency vehicle recognition signal is output to an external alarm device. After a fixed period from the input of the first input signal pattern, the contents stored in the pattern storage area of each emergency vehicle in the RAM 8c are cleared.

The same pattern is repeated for the siren sound of the emergency vehicle. After the pattern of the input signal is confirmed a predetermined number of times by the above configuration, an emergency vehicle recognition signal is output, thereby preventing erroneous recognition due to noise.

FIG. 5A is a block diagram showing a fourth embodiment of the present invention. In the figure, reference numeral 1 denotes an omnidirectional microphone that picks up a siren sound of an emergency vehicle, and is arranged outside a vehicle. As shown in FIG. 5B, the microphones 1 are arranged rearward, front right, and front left at intervals of 120 ° on the same plane. Microphones 1, 1 ...
Are input to preamplifiers 2, 2a, and 2b through bandpass filters 7, 7a, and 7b, respectively. The band pass filters 7, 7a and 7b are narrow band filters adapted to the band of the siren sound of the emergency vehicle,
Block the passage of noise. Preamplifiers 2, 2a and 2b
Amplifies the signal for each channel of each microphone and outputs it to the azimuth calculation unit 9. The azimuth calculation unit 9 calculates the azimuth of the emergency vehicle from the own vehicle from the three-channel microphone output, and outputs an azimuth display signal to an external alarm device. The alarm indicates the location of the emergency vehicle on a display or display. To calculate the azimuth, first, the signals of the two microphones are calculated to determine the sound intensity (the sound energy flowing in a unit area per unit time) in the direction of the central axis of the two microphones. When the sound intensities of the two axes that are not parallel are obtained in this way, since they are components of the two axes of the vector, the vector of the sound intensity is obtained by vector synthesis, and the direction of the sound source and the sound intensity Is required.

In the above configuration, the microphones 1, 1.
It is preferable that the microphone has a small omnidirectional with a sensitivity deviation of 0.5 dB or less, and it is necessary to arrange microphones at intervals of 1 cm to several mm. In addition, in addition to the arrangement shown in FIG. 5B, they may be arranged on the left, right, and rear as shown in FIG. 5C. Further, as shown in FIG. 5D, the microphone input is made up of four channels, and the microphones are arranged in front and rear and left and right, so that the detection accuracy in all directions can be improved. A siren sound having a distortion component, that is, a level higher than two harmonics, requires sensitivity up to a relatively high frequency band. Also,
As the frequency of the detected sound increases, the interval between microphones needs to be narrowed. For example, at intervals of 5 mm, sound collection up to 10 kHz is possible. Also, noise components are included in the sound wave input to the microphone, and the detection accuracy is improved by removing these noise components by the bandpass filters 7, 7a, and 7b.

[0018]

According to the emergency vehicle detection device of the present invention,
Since a signal is output to the alarm device upon detection of the approach of the emergency vehicle without being disturbed by the noise of the surrounding environment, safety can be maintained even when the volume of a car stereo or the like is being listened to.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a first reference example of the present invention.

FIG. 3 is a block diagram showing a second reference example of the present invention.

FIG. 4 is a block diagram showing a third reference example of the present invention.

5 (a) is a block diagram showing a fourth embodiment of the present invention, FIG. 5 (b) is a diagram showing an arrangement of microphones in the embodiment, and FIGS. 5 (b) and (c) are the same. FIG. 14 is a diagram illustrating a modification of the microphone arrangement in the reference example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microphone 2 Preamplifier 3 Emergency vehicle recognition part 4 Microphone control part 5 Variable gain amplifier 6 Level control part 7 Bandpass filter 8 False recognition prevention part 9 Direction calculation part

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor, Democracy Takeda 2-17-5 Shibuya, Shibuya-ku, Tokyo Inside Kenwood Corporation (72) Inventor Shuhei Ota 2-17-5 Shibuya, Shibuya-ku, Tokyo (56) References JP-A-1-93797 (JP, A) JP-A-2-22799 (JP, A) JP-A-60-95598 (JP, A) JP-A-2-200046 (JP, A A) JP-A-62-119482 (JP, A) JP-A-58-221500 (JP, A) JP-A-54-46473 (JP, A) JP-A-56-129999 (JP, A) -8216 (JP, B2) JP-B-54-30271 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G08G 1/00-1/16

Claims (3)

(57) [Claims] A microphone for picking up a siren sound of an emergency vehicle, an emergency vehicle recognition unit for recognizing that an output signal of the microphone is a siren sound of an emergency vehicle, and a microphone control for controlling passage of the output signal of the microphone. The output circuit of the microphone is turned on and off at a constant cycle until the emergency vehicle recognition unit recognizes the siren sound of the emergency vehicle, and is turned on for a predetermined period once the emergency vehicle recognition unit recognizes the siren sound of the emergency vehicle. An emergency vehicle detection device configured to output an emergency vehicle recognition signal when the same siren sound is recognized again, and to return to the original state of turning on and off the output circuit of the microphone at a constant cycle if the same siren sound is not recognized again . 2. The emergency vehicle recognition signal is output when the same siren sound is recognized a plurality of times again.
Emergency vehicle detection device. 3. The emergency vehicle detection according to claim 1, wherein the period during which the output circuit of the microphone is turned on once the emergency vehicle recognition unit recognizes the siren sound of the emergency vehicle is determined according to the length of the initial siren sound. apparatus.