JP2006268455A - Apparatus for generating notification sound in vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for generating a notification sound in a vehicle preventing the notification sound from being hard to hear due to a noise around a driver. <P>SOLUTION: Sensors A-C detect abnormality such as approach of other vehicles, to output detection signals. Microphones 7-9 detect the noise around the driver. A spectrum analysis apparatus 11 detects a frequency characteristic of a synthetic signal outputted from the microphones 7-9. A CPU 1 inputs the frequency characteristic of the ambient noise from the spectrum analysis apparatus 11 when the detection signal is outputted from any of the sensors A-C, detects a frequency whose frequency component is comparatively low level among respective frequency components of the noise from the frequency characteristic, and outputs data showing the detected frequency to an oscillator 13. The oscillator 13 generates a notification signal including a frequency component corresponding to the data outputted from the CPU 1, to output it to a speaker 15 via an amplifier 14. The speaker 15 emits a sound of the notification signal as a notification sound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle notification sound generating device that provides warnings such as rear-end collision prevention and drowsiness prevention to a driver of an automobile, or notification of operation of a lever or the like.

  With the development of ITS (Intelligent Trasport System), an in-vehicle warning sound generating device has been developed that detects various dangers inside and outside the vehicle with a sensor or the like during driving and warns the driver of the danger by an alarm sound. In this apparatus, the alarm sound is generated, for example, for preventing rear-end collision, lane keeping, preventing rear collision, preventing drowsiness, etc., and an automobile equipped with such an apparatus is an ASV (Advanced Safety Vehicles). It is said.

By the way, the conventional in-vehicle warning sound generating device always warns the driver of the occurrence of danger by the same warning sound. However, road noise, surrounding traffic noise, audio sounds, and various other noises (interfering noises) for warning sounds enter the driver's ears, and these noises are road conditions, traffic volume outside the vehicle, vehicle speed, etc. It changes sequentially. For this reason, when the alarm sound is the same, the alarm sound may be difficult to hear. In addition, it may be difficult to hear the notification sound for informing the operation of a lever or the like in the vehicle.
JP 7-322403 A

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an in-vehicle notification sound generating device that does not make it difficult to hear a notification sound in accordance with noise around the driver.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The invention according to claim 1 is an in-vehicle notification sound generator that detects an event occurring in a vehicle and notifies the driver by sound. A sensor for detecting an event and outputting a detection signal; a detection means for detecting a frequency characteristic of noise around the driver; a detection signal output from the sensor; and a frequency characteristic input from the detection means; A first control means for detecting a frequency component having a relatively low level among the frequency components of the noise from the frequency characteristics, and outputting data indicating the detected frequency, and an output from the first control means An in-vehicle notification sound generating device comprising: a notification sound generating means for generating a notification sound having a frequency corresponding to the recorded data.

According to a second aspect of the present invention, in the in-vehicle notification sound generating device according to the first aspect, in place of the first control unit, a detection signal output from the sensor is received, and a frequency characteristic is obtained from the detection unit. A table in which the frequency of the frequency component having a relatively low level among the frequency components of the noise is detected from the frequency characteristics, the data indicating the detected frequency is stored, and the data indicating the loudness of the human ear is stored. And a second control means for determining a frequency based on the corrected data and outputting data indicating the determined frequency.
According to a third aspect of the present invention, in the in-vehicle notification sound generating device according to the first or second aspect, the notification sound generating means is configured such that when the data output from the control means is higher than a predetermined frequency, Instead of a notification sound having a frequency corresponding to data, a sound in which a frequency component of the data is enhanced is generated.

  According to the present invention, the notification sound does not become difficult to hear according to the noise around the driver, and the driver can always reliably hear the notification sound. As a result, there is an advantage that the danger that occurs during driving of the vehicle can be more easily avoided.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an in-vehicle notification sound generator according to an embodiment of the present invention. In this figure, reference numeral 1 is a CPU (central processing unit) for controlling each part of the apparatus, and 2 is a ROM (read only memory) in which a program of the CPU 1 and a loudness table are stored. Here, the loudness table is a table in which loudness data indicating the sensitivity of the human ear is stored for each frequency band. In general, the human ear is most sensitive to sounds in the 2-5 KHz band, and the loudness data (dB) in that band is low, and it is sensitive to both low frequency and high sound. And the loudness data (dB) in that band is high.

  Reference numeral 3 denotes a RAM (random access memory) for temporarily storing data. Each of the sensors A to C is a sensor for detecting an event that occurs in various vehicles, but in the present embodiment, it is a sensor for detecting a danger that occurs during driving. For example, a front approach sensor that detects that the vehicle has approached the vehicle ahead of a certain distance and outputs a detection signal, a rear approach sensor that detects that the vehicle behind has approached a distance of a certain distance and outputs a detection signal, There is a sleep sensor that detects that the driver is in a sleep state and outputs a detection signal.

  When the interface 5 receives a detection signal notifying the occurrence of danger from any of the sensors A to C, the interface 5 outputs sensor data including the code number of the sensor and data indicating the occurrence of danger to the CPU 1. Reference numerals 7 to 9 denote microphones for detecting in-vehicle noise and outside-vehicle noise, and are installed at appropriate locations of the vehicle. A synthesis circuit 10 synthesizes output signals from the microphones 7 to 9 and outputs the synthesized signals to the spectrum analyzer 11. The spectrum analyzer 11 performs frequency analysis on the output signal of the synthesis circuit 11 by an analysis technique such as FFT (Fast Fourier Transform), LPC (Linear Prediction Analysis), etc., every time a predetermined time elapses, and obtains a spectrum envelope. Store in the memory. Then, in response to a request from the CPU 1, the analysis result in the memory is output to the CPU 1 via the bus line B.

  An oscillator 13 generates an AC signal having a frequency indicated by frequency data (described later) supplied from the CPU 1 via the bus line B and outputs the AC signal to the amplifier 14. The amplifier 14 amplifies the output signal of the oscillator 13 and outputs it to the speaker 15. The speaker 15 is installed at a position relatively close to the driver in the vehicle and generates an output signal from the amplifier 14 as a notification sound.

Next, the operation of the above-described in-vehicle notification sound generating device will be described with reference to the flowchart shown in FIG.
When the apparatus is powered on, the CPU 1 first instructs the interface 5 to output sensor data, and inputs the sensor data output from the interface 5 (step S1). Then, it is determined whether or not the sensor data is data indicating that there is an abnormality (occurrence of danger) (step S2). If the determination result is “NO”, the process returns to step S1, and thereafter step S2 Steps S1 and S2 are repeated until the determination becomes “YES”.

  Next, when sensor data indicating the occurrence of danger is output from the interface 5, the determination result in step S2 is “YES”, and the process proceeds to step S3, where the CPU 1 instructs the spectrum analyzer 11 to output data. The spectrum analyzer 11 receives the instruction, and outputs the spectrum analysis result (spectrum envelope: see FIG. 2) of the synthesis circuit 10 to the CPU 1. The CPU 1 receives the spectrum analysis result input from the spectrum analyzer 11. Is stored in the RAM 3 (step S3).

Next, the CPU 1 proceeds to step S4, and detects the valley of the envelope (see the arrow in FIG. 2) stored in the RAM 3. Next, the process proceeds to step S5, where the detected valley levels (dB) are sorted in ascending order, for example, the next noise data table is created and stored in the RAM 3.
Frequency (Hz) Level (dB)
1200 5
2000 7
550 12
230 18

Next, the process proceeds to step S6, and weighting correction by loudness is performed on the above data. That is, the loudness data (dB) of each frequency is read from the loudness table stored in the ROM 2 in advance, and the read loudness data is added to the level data. For example, the following new noise data table is obtained. Created in RAM3.
Frequency (Hz) Level (dB)
1200 11.0
2000 8.5
550 19.5
230 31.2

Next, the process proceeds to step S7, and the lowest level frequency is detected from the loudness corrected noise data table. In this case, 2000 Hz is detected. Next, the process proceeds to step S8, and the frequency data indicating the detected frequency is output to the oscillator 13.
The oscillator 13 generates an AC signal having the frequency indicated by the frequency data input from the CPU 1 and outputs the AC signal to the speaker 15 via the amplifier 14. As a result, a notification sound for notifying the occurrence of an abnormality from the speaker 14 is generated, and the notification sound having the lowest ambient noise component at that time and having a good loudness characteristic is generated. As a result, the driver can reliably detect the notification sound. Note that the flow after step S8 returns to the start, and if sensor data indicating danger is continuously output from the interface 5 in step S2, the processing of steps S3 to S8 is performed to continuously generate the notification sound.

  The above is the content of the embodiment of the present invention. Noise around the driver changes sequentially depending on road conditions, traffic volume outside the vehicle, vehicle speed, engine speed, and the like. According to the above embodiment, the spectrum analyzer 11 always analyzes the frequency of ambient noise, and the CPU 1 instructs the oscillator 13 on the frequency of the notification sound according to the analysis result, so that it corresponds to the noise at that time. A notification sound that is easy to hear can be generated.

In the above embodiment, the same notification sound is generated when a detection signal is output from any of the sensors A to C. Instead, a different notification sound is generated for each sensor. You may do it. For example, when a detection signal is output from the sensor A, a continuous sound, when a detection signal is output from the sensor B, a short-period intermittent sound, and when a detection signal is output from the sensor C, a long-period intermittent sound To generate.
In the above embodiment, the lowest level frequency is detected in step S7 of FIG. 2. However, a frequency having a relatively low level may be detected if not the lowest level.

  In the above embodiment, the frequency of the notification sound is determined only by the noise data table after the loudness correction. In this case, the notification sound frequency may be in a high frequency band depending on the frequency characteristics of the ambient noise. At this time, the notification sound becomes a high pitch sound of “pea”, which may be difficult to hear. Therefore, when the frequency determined from the noise data table is higher than a certain level, the basic frequency of the notification sound is set to a normal frequency lower than the frequency determined from the table, and the harmonic component of the sound is enhanced with the frequency component determined from the table. Also good. By doing so, it is possible to generate an easily audible notification sound that is not masked by noise while being a normal pitch sound. In the above-described embodiment, the sound for notifying danger is described. However, the sound may be applied to sound indicating operation of an ignition key or various levers, time signal sound, notification sound such as car navigation.

  The present invention is used in vehicles such as passenger cars and commercial vehicles.

It is a block diagram which shows the structure of the notification sound generator in a vehicle by one Embodiment of this invention. It is a flowchart for demonstrating operation | movement of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... CPU, 2 ... ROM, 3 ... RAM, 5 ... Interface, 7-9 ... Microphone, 11 ... Spectrum analyzer, 13 ... Oscillator, 14 ... Amplifier, 15 ... Speaker, AC ... Sensor.

Claims (3)

In-vehicle notification sound generator for detecting an event occurring in a vehicle and notifying the driver by sound,
A sensor that detects a predetermined event and outputs a detection signal;
Detection means for detecting frequency characteristics of noise around the driver;
The detection signal output from the sensor is received, the frequency characteristic is input from the detection means, and the frequency component having a relatively low level among the frequency components of the noise is detected and detected from the frequency characteristic. First control means for outputting data indicating the frequency;
Notification sound generating means for generating a notification sound having a frequency corresponding to the data output from the first control means;
An in-vehicle notification sound generating device comprising: Instead of the first control means,
The detection signal output from the sensor is received, the frequency characteristic is input from the detection means, and the frequency component of the frequency component having a relatively low level is detected and detected from the frequency characteristic. Data indicating the frequency is corrected by a table storing data indicating the loudness of the human ear, a second control unit is provided that determines the frequency based on the corrected data and outputs data indicating the determined frequency. The in-vehicle notification sound generating device according to claim 1.   When the data output from the control means is higher than a predetermined frequency, the notification sound generating means generates a sound in which the frequency component of the data is enhanced instead of the notification sound of the frequency corresponding to the data. The in-vehicle notification sound generator according to claim 1 or 2, wherein

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