JP2007065832A - Exterior noise processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exterior noise processor for detecting an object approaching by emitting a sound in various traveling states. <P>SOLUTION: This exterior noise processor is configured of a microphone 1 for picking up an exterior noise; a vehicle state detecting part 4 for detecting the state of a vehicle; a storage part 13 for storing an acoustic signal picked up by the microphone 1 by associating it with a vehicle state when the acoustic signal is picked up; a vehicle sound/vehicle state contrast storing part 15 for storing information acquired by averaging the acoustic signals in a predetermined period for each vehicle state by associating it with the state of the vehicle; a vehicle sound comparing part 16 for comparing the acoustic signal collected by the microphone 1 when the vehicle travels with the averaged information corresponding to the vehicle state when the acoustic signal is picked up; and an approach deciding part 17 for deciding that there is an object approaching the vehicle when the acoustic signal when the vehicle travels is larger and becomes larger successively than the averaged vehicle sound as the result of the comparison of the acoustic signal when the vehicle travels with the averaged information corresponding to the vehicle state at that time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle exterior sound processing apparatus that notifies a driver that there is an object approaching a vehicle by a sound outside the vehicle.

  In recent vehicles, the sound insulation performance of the vehicle has been improved in order to improve the comfort of passengers on the move, and to reduce the fatigue caused by noise on the driver. In addition, the vehicle is often provided with an audio device, and music and broadcasts are often heard while traveling. In such a situation, since it is difficult to hear the sound outside the vehicle, the driver may be delayed in noticing the approach of a motorcycle or emergency vehicle approaching from the blind spot of the vehicle.

  Notifying the driver of the existence of an object approaching the vehicle early is effective in causing the driver to perform an avoidance operation quickly and avoiding a dangerous operation to improve driving safety.

  Conventionally, a technique for informing the driver of the sound outside the vehicle has been proposed. For example, Patent Document 1 describes a technique in which a specific sound is registered in advance and a passenger is notified when a sound outside the vehicle matches the specific sound. In the technique of Patent Document 1, when the outside sound collected by the microphone attached to the vehicle is compared with the registered sound and the outside sound matches any of the registered sounds, the outside sound or the outside sound of the vehicle is detected. The registered voice that matches the sound is released into the passenger compartment.

  However, in the technique of Patent Document 1, it is essential to register a specific sound in advance in order to determine as a useful vehicle outside sound, and the unregistered sound is out of scope. For example, a two-wheeled vehicle approaching at the blind spot of the own vehicle has a high possibility that it cannot be determined as useful information for safe driving because it is difficult to register uniquely depending on the vehicle type and riding situation.

  Patent Document 2 describes a technique of an in-vehicle electronic device that processes an electric signal converted by a microphone in a vehicle interior. The technology of Patent Document 2 is characterized by analyzing the frequency of sound generated outside the passenger compartment, judging the approach of an emergency vehicle such as an ambulance or police car, and notifying the approach information by voice.

  However, in the technique of Patent Document 2, the object to be detected by detecting the sound outside the vehicle and being notified to the driver is limited to the emergency vehicle. Information other than emergency vehicles cannot be determined as information useful for safety.

  Patent Document 3 describes the following technique. The acoustic signals output from the plurality of microphones arranged at a predetermined interval are converted into corrected acoustic signals from which the frequency components of the low frequency band and the high frequency band are removed by the band pass filter. The corrected acoustic signal is limited to a predetermined frequency band in which the characteristics of the running sound of the vehicle often appear by the band limiter, the power is calculated by the power calculator, and an approaching vehicle is present when the power is greater than the predetermined value by the proximity determiner. Determined. The corrected acoustic signal is converted into a noise suppression signal from which unnecessary noise components are removed by a noise suppressor. The correlation calculator calculates the cross-correlation of the plurality of noise suppression signals, and the time difference calculator calculates the arrival time difference that maximizes the correlation. The approaching direction of the approaching vehicle is calculated from the arrival time difference by the direction calculator.

Patent Document 3 calculates the power of a frequency band in which the characteristics of the traveling sound of an approaching vehicle often appear when determining the approaching vehicle. However, when a vehicle of the same type as the host vehicle approaches, the approaching vehicle cannot be determined because the power level of the driving sound of the host vehicle is high because of the same type of driving sound as the driving sound of the host vehicle. Patent Document 3 does not describe detecting the state of the vehicle, and does not describe a method for suppressing the generated sound of the host vehicle according to the state of the vehicle. Many examples of vehicle running conditions, such as the transmission gears differing, can cause a significant difference in the sound generated by the engine even at the same speed, whether the cooling fan is operating, the type of tire, braking Depending on the sound of time, the sound generated by the vehicle changes. Therefore, in the technique of Patent Document 3, the approaching vehicle may not be correctly determined depending on the state of the vehicle and the type of approaching vehicle.
JP-A-8-2339 JP-A-6-245289 Japanese Utility Model Publication No. 5-92767

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle exterior sound processing device that can detect an object approaching by emitting sound in various operating states of each device of the vehicle. To do. It is another object of the present invention to extract specific acoustic information in various operating states of each device of the vehicle to correctly notify the driver of an approach such as an emergency vehicle or a railroad crossing.

  In order to achieve the above object, a vehicle exterior sound processing apparatus according to a first aspect of the present invention includes an acoustic signal collecting means provided in a vehicle for collecting sounds outside the vehicle, and each device of the vehicle. Vehicle state detection means for detecting a vehicle state in an operating state; a storage unit for storing the acoustic signals collected by the acoustic signal collection means in association with the vehicle state when the acoustic signals are collected; Vehicle sound-vehicle state comparison storage means for storing information obtained by averaging the stored acoustic signals over a predetermined period for each vehicle state in association with the vehicle state, and collected by the acoustic signal collection means during vehicle travel Vehicle sound comparison means for comparing the averaged information corresponding to the vehicle state when the acoustic signal was collected, and the vehicle sound comparison means when the vehicle sound is traveling Vehicle shape As a result of comparing the averaged information corresponding to the vehicle, an approach determination that determines that there is an object approaching the vehicle when an acoustic signal during vehicle travel is larger than the averaged information and sequentially increases And means.

  Furthermore, a plurality of the acoustic signal collection means and an acoustic direction comparison means for comparing the acoustic signals collected by the plurality of acoustic signal collection means, the acoustic direction comparison means, wherein the approach determination means is the vehicle When it is determined that there is an approaching object, the arrival direction of the approaching object is determined by comparing the acoustic signals collected by the plurality of acoustic signal collecting means.

  Further, specific sound storage means for storing acoustic information of the specific sound outside the vehicle, specific sound comparison means for comparing the sound of the approaching object with the specific sound, and a display for displaying the approach of the sound source of the specific sound And the specific sound comparing means corresponds to the matching specific sound when the sound of the approaching object matches the specific sound stored in the specific sound storage means. The approach of the sound source is displayed on the display.

  When the vehicle is provided with an audio device, the vehicle further includes an audio signal suppression unit that suppresses the audio signal of the audio device from the audio signal collected by the audio signal collection unit and generates an audio signal outside the vehicle. preferable.

  Preferably, the acoustic signal collected by the acoustic signal collecting means is digitized and processed as frequency information and / or time axis information.

  As the operation state of each device of the vehicle in the vehicle state, vehicle speed, accelerator opening, engine speed, acceleration / deceleration state, transmission state, steering steering angle, wiper operation state, air conditioner operation state, electric fan operation state Any combination of the window open / close state, the horn operating state, and the type of tire mounted on the vehicle may be included.

  According to the vehicle exterior sound processing device of the present invention, an acoustic information database (vehicle sound-vehicle state comparison memory) corresponding to various operating states of each device of the vehicle is constructed, and from the acoustic signals collected by the acoustic signal collecting means. Since the characteristic vehicle sound component of the host vehicle corresponding to the vehicle state when the acoustic signal is collected is suppressed, the sound outside the vehicle can be detected correctly. Then, when the detected sound outside the vehicle increases sequentially, it is determined that there is an object approaching the vehicle, so the presence of the approaching object can be correctly determined.

(Embodiment 1)
An embodiment of a vehicle exterior sound processing apparatus 100 according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a vehicle exterior sound processing apparatus 100 according to an embodiment of the present invention. The structure of each part of the vehicle exterior sound processing apparatus 100 shown in FIG. 1 will be described. The microphone 1 is an acoustic signal collecting unit that collects sound outside the vehicle. The acoustic signal collected by the microphone 1 is amplified by the microphone amplifier 5, converted to a digital signal by the A / D converter 7, and input to the vehicle interior sound suppression unit 11. The audio signal input unit 3 inputs an audio signal of an audio device (not shown) provided in the vehicle. The audio signal is converted into a digital signal by the A / D converter 9 and input to the in-vehicle sound processing unit 12. The sampling frequency in the A / D converters 7 and 9 is several times to 10 times the maximum frequency effective for recognizing the sound generated by the approaching object. For example, when the maximum frequency for recognizing the sound generated by the approaching object is 10 kHz, the sampling frequency is about 40 kHz to 50 kHz.

  The vehicle state detection unit 4 detects the operating state of each device of the vehicle. The operating state of each device of the vehicle includes, for example, vehicle speed, accelerator opening, engine speed, acceleration / deceleration state, transmission state, steering steering angle, wiper operating state, air conditioner operating state, electric fan operating state, window There are open / closed states, horn operating states, and types of tires mounted on the vehicle. In order to detect the operating state of each device of the vehicle, operating state information is input from a vehicle control device (not shown). Alternatively, each device described above is provided with a detector to detect its state. Alternatively, operating state information is input from the control unit of each device of the vehicle. The vehicle state information detected by the vehicle state detection unit 4 is transmitted to the vehicle interior sound processing unit 12 and the address generation unit 10.

  The in-vehicle sound processing unit 12 is composed of, for example, a variable band filter capable of changing the amplification degree of the audio signal for each band, and adjusts the audio signal to be subtracted and suppressed from the acoustic signal outside the vehicle according to the vehicle state. For example, since the magnitude of the sound of the audio device in the vehicle that wraps around the microphone 1 changes depending on the open / close state of the window, the degree of amplification of the audio signal to be subtracted and suppressed is adjusted according to the open / close state of the window. The audio signal adjusted by the vehicle interior sound processing unit 12 is input to the vehicle interior sound suppression unit 11.

  The vehicle interior sound suppression unit 11 includes a subtraction circuit for obtaining a difference between acoustic signals and a Fourier transform circuit, and subtracts and suppresses the audio signal adjusted by the vehicle interior sound processing unit from the acoustic signal collected by the microphone 1. For the suppression of the audio signal, the difference can be obtained with the time axis information (sound waveform). After suppressing the audio signal from the acoustic signal with the time axis information, the frequency information is obtained. First, the acoustic signal and the audio signal may be Fourier-transformed to obtain frequency information, and the difference may be obtained from the frequency information. In order to obtain frequency information, an acoustic signal and an audio signal are accumulated for a certain period of time, and Fourier transform is performed at each certain time interval. Thereafter, processing is performed at regular intervals.

  The acoustic signal in which the audio signal is suppressed is sent to and stored in the storage unit 13. The acoustic signal stored in the storage unit 13 is averaged over a predetermined period for each vehicle state by the averaging processing unit 14. The sound signal is averaged for each frequency. The vehicle sound-vehicle state comparison storage unit 15 stores the vehicle sound obtained by averaging the acoustic signals over a predetermined period for each vehicle state by the averaging processing unit 14.

  The averaging processing unit 14 weights and averages the averaged vehicle sound corresponding to the vehicle state at that time and the current acoustic signal, and uses the vehicle sound − as the averaged vehicle sound corresponding to the vehicle state. The storage in the vehicle state comparison storage unit 15 is updated. For example, assuming that N is a positive integer, the averaged sound is multiplied by N-1 and the sound signal is added and divided by N to obtain a new averaged vehicle sound. For example, when N is 100, the acoustic signal first becomes 1/100, and thereafter becomes 99/100 each time, and the contribution rate to the averaged vehicle sound decreases gradually.

  As an averaging method, a moving average of a predetermined number of acoustic signals having the same vehicle state may be taken. For averaging, the difference between the current acoustic signal (with the audio signal suppressed) and the averaged vehicle sound may be subtracted from the current acoustic signal, but it may be averaged even in the same vehicle condition in the long term. Since the sound may change, the audio signal may be averaged with the suppressed acoustic signal. In this way, for example, when a tire is replaced, it is possible to follow seasonal variations or long-term changes.

  The vehicle sound-vehicle state comparison storage unit 15 is a non-volatile memory such as a flash memory, a hard disk, a DVD (Digital Versatile Disc), a DVD-RAM (Digital Versatile Disc Random Access Memory), a DVD-RW (Digital Versatile Disc Rewritable). Consists of

  FIG. 2 is a diagram illustrating an example of the structure of the vehicle sound-vehicle state comparison storage unit 15. A bit is assigned to each item of the vehicle state, and an address where the averaged vehicle sound is stored corresponding to the bit pattern determined by the state of 0 or 1 of each bit (vehicle sound storage location) Is assigned. Each bit is determined by the vehicle state information, and an averaged vehicle sound corresponding to the vehicle state can be extracted with reference to the vehicle sound storage location of the row that matches the bit pattern.

  The vehicle state includes vehicle speed (vehicle speed), transmission stage, accelerator opening, engine speed, acceleration / deceleration, steering angle, wiper operation, air conditioner operation, electric fan operation, window opening, There is a horn operating state. For example, the vehicle speed is a numerical value that increases by 1 every 10 km / h. Since the state of the transmission is 8 stages including, for example, 5 forward stages, 1 reverse stage, neutral and parking, 3 bits are allocated. Similarly, for example, 3 bits are assigned to the accelerator opening, 4 bits are assigned to the engine speed, and 3 bits are assigned to the acceleration / deceleration state. In the wiper operation, for example, 2 bits are assigned as 4 stages of stop, intermittent, continuous, and high speed. In the air conditioner operating state, for example, a total of 3 bits are allocated to the operation of the fan of the heat pump and the heat exchanger and the operation of the indoor fan. For example, 2 bits are assigned to the operating state of the electric fan. As the opening of the window, for example, 3 bits are assigned in 8 stages including the fully closed state as a whole. For example, 2 bits may be allocated for each window. If the horn is only ON / OFF, 1 bit is sufficient. In the example of FIG. 2, the vehicle state is 31 bits in total. The items constituting the vehicle state and the number of bits can be added or changed as appropriate according to the vehicle. For example, raindrop sensor information may be added to add the strength of rain to one of the vehicle conditions. Further, in addition to the vehicle state, the type of tire may be handled as different vehicle sounds depending on the type of steel radial tire for summer, studless tire for winter, tire width size, flatness, and the like.

  The address generation unit 10 generates an address in the vehicle sound-vehicle state comparison storage unit 15 in which the averaged vehicle sound corresponding to the vehicle state is stored, and instructs the vehicle sound-vehicle state comparison storage unit 15. For example, 31-bit information corresponding to the vehicle state shown in FIG. 2 is generated from the vehicle state information detected by the vehicle state detection unit 4, and the vehicle sound storage location corresponding to the generated 31-bit information is shown in FIG. Extract from the data represented by the structure.

  The vehicle sound stored in the vehicle sound storage location instructed by the address generation unit 10 is input from the vehicle sound-vehicle state comparison storage unit 15 to the vehicle sound comparison unit 16. Further, the acoustic signal stored in the storage unit 13 is input to the vehicle sound comparison unit 16. The vehicle sound comparison unit 16 includes a subtraction circuit, and subtracts the vehicle sound averaged from the acoustic signal for each frequency component. That is, in this Embodiment 1, the vehicle sound comparison part 16 suppresses the averaged vehicle sound corresponding to the vehicle state at that time from an acoustic signal.

  FIG. 3 is a schematic diagram illustrating an example in which the difference between the acoustic signal and the averaged vehicle sound is enlarged. FIG. 3A shows a state in which the sound of the approaching object is superimposed on the vehicle sound. For convenience, the lower solid line indicating the vehicle sound and the upper solid line indicating the superimposed sound are separated, but the observed data is the upper solid line. In the example of FIG. 3, the case where an acoustic signal is Fourier-transformed into frequency information is shown. (B) of FIG. 3 shows the acoustic component other than the own vehicle, which is the remainder obtained by subtracting (suppressing) the spectrum of the vehicle sound from the spectrum of (a). FIG. 3C shows a state where acoustic components other than the own vehicle are increasing. Thus, when the acoustic components other than the own vehicle are increasing, it can be determined that there is an approaching object.

  As a method for comparing the acoustic signal and the vehicle sound, there is the following method in addition to the subtraction for each frequency component described above. Assuming that the acoustic signal and the vehicle sound are given by frequency information, there is a method of calculating the acoustic energy of the two first and taking the difference of the acoustic energy. Moreover, when an acoustic signal is given by time-axis information, there is a method of calculating acoustic energy from time-axis information and subtracting vehicle sound energy. In this case, the energy value of the vehicle sound may be stored in the vehicle sound-vehicle state comparison storage unit 15. Alternatively, in each of the above cases, the ratio of both energy values may be taken.

  The acoustic signal in which the vehicle sound averaged by the vehicle sound comparison unit 16 is suppressed is input to the approach determination unit 17. The approach determination unit 17 includes an integrator for an acoustic signal, a memory, and a comparator. The approach determination unit 17 integrates the energy of the acoustic signal and accumulates the values of the plurality of latest acoustic signal energies. Then, when the acoustic signal energy value is equal to or greater than a predetermined value and sequentially increases, it is determined that there is an object approaching the vehicle. For example, if the acoustic signal is processed every 100 milliseconds, and the acoustic signal energy value is increased ten times consecutively, it is determined that there is an object approaching the vehicle. When it is determined that there is an object approaching the vehicle, the approach determination unit 17 instructs the output unit 18 to display an alert.

  When the acoustic signal increases sequentially, the number of continuous acoustic signal expansions for determining that there is an object approaching the vehicle and the threshold for determining that the acoustic signal has increased are the values of environmental changes outside the vehicle. Set to eliminate the impact. For example, the acoustic signal may increase as the pavement changes from asphalt to concrete or enters a tunnel. In such a case, a predetermined number of times and a threshold value are set so as not to erroneously determine that there is an object approaching the vehicle.

  The output unit 18 is connected to a speaker 19 and a display 20. The output unit 18 includes a device that stores audio information to be notified, and selects and reproduces and amplifies the audio information. Moreover, the information which displays on the display 20 is stored, and the display drive part which displays the information on the display 20 is included. The output unit 18 displays the alert data on the speaker 19 and the display 20 when the alert display is instructed from the approach determination unit 17. That is, audio information stored in the sound source is output from the speaker 19, and the display 20 is driven to display data.

  Of the exterior sound processing apparatus 100, the address generation unit 10, the interior sound suppression unit 11, the interior sound processing unit 12, the storage unit 13, the averaging processing unit 14, the vehicle sound comparison unit 16, and the approach determination unit 17 are all or A part can be constituted by a DSP (Digital Signal Processor).

  Next, the operation of the vehicle exterior sound processing apparatus 100 of FIG. 1 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the first embodiment.

  First, sound outside the vehicle (acoustic signal) is collected by the microphone 1 and an audio signal is input by the audio signal input unit 3 (step A1). At the same time, the vehicle state at that time is input by the vehicle state detector 4 (step A2). As described above, the acoustic signal and audio signal outside the vehicle are digitized by the A / D converters 7 and 9, the audio signal is adjusted according to the vehicle state by the vehicle interior sound processing unit 12, and the vehicle interior sound suppression unit 11 The audio signal is suppressed from the acoustic signal (step A3). The acoustic signal in which the audio signal is suppressed is stored in the storage unit 13. From the vehicle state information, an address of the vehicle sound-vehicle state comparison storage unit 15 in which the averaged vehicle sound corresponding to the vehicle state is stored is generated, and the address corresponding to the vehicle state is generated from the vehicle sound-vehicle state comparison storage unit 15. Reference is made to the averaged vehicle sound (step A4).

  The vehicle sound comparison unit 16 compares the acoustic information in which the audio signal is suppressed with the averaged vehicle sound corresponding to the vehicle state (step A5). The processing so far is performed at predetermined time intervals.

  Based on the comparison result, the approach determination unit 17 determines whether there is an object approaching the vehicle (step A6). A value obtained by comparing the acoustic information outside the vehicle at regular time intervals and the averaged vehicle sound corresponding to each vehicle state is accumulated for the most recent predetermined number of times, and the acoustic information outside the vehicle is continuously stored a predetermined number of times. If it is larger, it is determined that there is an object approaching the vehicle. For example, it is determined that there is an object approaching the vehicle when the predetermined time is 100 milliseconds and the acoustic signal is larger than the immediately preceding acoustic signal for ten consecutive times.

  Then, when there is an approaching object (step A7; Yes), a warning display is performed by the output unit 18 (step A8). Whether there is an approaching object or not (step A7; No), the averaging processing unit 14 weights the averaged vehicle sound corresponding to the vehicle state at that time and the current vehicle sound. Then, the storage of the vehicle sound-vehicle state comparison storage unit 15 is updated as an averaged vehicle sound corresponding to the vehicle state (step A9). The averaging process is performed every predetermined time interval (for example, 100 milliseconds). The averaged vehicle sound other than the vehicle state at that time is not updated at that time.

  As a result, an acoustic information database (vehicle sound-vehicle state comparison storage) corresponding to the vehicle running state unique to the host vehicle is constructed, and the acoustic signal is collected from the acoustic signal collected by the acoustic signal collecting means. Since the characteristic component of the vehicle running sound corresponding to the vehicle state is efficiently suppressed, the sound outside the vehicle can be detected correctly. Then, when the detected sound outside the vehicle increases sequentially, it is determined that there is an object approaching the vehicle, so the presence of the approaching object can be correctly determined. Further, since the audio signal is subtracted from the acoustic signal according to the vehicle state at that time, the approaching object can be more accurately determined.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the vehicle exterior sound processing apparatus 100 includes a plurality of acoustic signal collection units, and the acoustic signals collected by the plurality of acoustic signal collection units are compared by the acoustic azimuth comparison unit. Determine the direction of arrival. FIG. 5 is a plan view of a vehicle showing an example of the arrangement of acoustic signal collecting means according to Embodiment 2 of the present invention. As shown in FIG. 5, for example, microphones 1a, 1b, 1c and 1d can be provided at four corners of the vehicle as acoustic signal collecting means.

  FIG. 6 is a block diagram of the vehicle exterior sound processing apparatus 100 according to the second embodiment. Compared to the first embodiment, there are a plurality (four) of microphones 1a, 1b, 1c, and 1d, and a microphone 2 that collects sound in the vehicle is added. Vehicle interior sound suppression units 11a, 11b, 11c, and 11d are provided for the microphones 1a, 1b, 1c, and 1d, respectively, and a vehicle sound storage unit 13, an averaging processing unit 14, and a vehicle sound-vehicle state comparison storage unit. 15 is also stored and processed separately for each microphone 1a, 1b, 1c, 1d.

  In the second embodiment, not only the audio signal but also the in-vehicle sound such as the sound generated by the occupant in the vehicle is suppressed from the acoustic signal by the in-vehicle sound suppressing units 11a, 11b, 11c, and 11d.

  The comparison between the acoustic signal and the averaged vehicle sound is performed for each of the microphones 1a, 1b, 1c, and 1d. Then, the result of each comparison is input to the sound direction comparison unit 21. The acoustic azimuth comparison unit 21 compares the acoustic signals outside the vehicle for each of the microphones 1a, 1b, 1c, and 1d to determine the direction of arrival of the sound.

  For example, the difference between the energy values of the microphones 1a, 1b, 1c, and 1d and the averaged vehicle sound, or the normalized ratio, can be expressed in the direction of the microphones 1a, 1b, 1c, and 1d. And the direction of the synthesized vector can be set as the arrival direction.

  Or, for example, the acoustic signal for each microphone 1a, 1b, 1c, 1d is compared with the averaged vehicle sound, and the difference between the two energy values or the normalized one is selected, The direction of the microphone may be the sound arrival direction. Furthermore, when the difference between the sound signal of the microphone adjacent to the microphone having the largest sound signal is equal to or less than a predetermined threshold value, the sound arrival direction may be set between the microphone of the maximum sound signal and the adjacent microphone. .

  The arrival direction determined by the sound direction comparison unit 21 is input to the output unit 18, and the arrival direction is displayed on the speaker 19 and the display 20. To display the direction of arrival of the sound, for example, 360 ° of the vehicle is divided into 8 directions of 45 ° each, that is, forward, right front, right, right rear, rear, left rear, left, left front However, the arrival direction may be classified and displayed in any direction. Only when it is determined that there is an object approaching the vehicle, the arrival direction of the acoustic signal may be displayed on the output unit 18.

  In the approach determination part 17, the increase rate of a sound can be represented numerically for every microphone 1a, 1b, 1c, 1d, and it can synthesize | combine and determine a result. Alternatively, the acoustic signals for the microphones 1a, 1b, 1c, and 1d may be synthesized, and it may be determined that there is an object approaching when the energy value sequentially increases.

  Next, the operation of the vehicle exterior sound processing apparatus 100 of FIG. 6 will be described with reference to FIG. FIG. 7 is a flowchart for explaining the operation of the vehicle exterior sound processing apparatus 100 according to the second embodiment. In FIG. 7, Step B1 to Step B6 are the same as Step A1 to Step A6 of FIG. In the second embodiment, a plurality of microphones 1a, 1b, 1c, and 1d are provided, and processing is performed for each of the microphones 1a, 1b, 1c, and 1d.

  As described above, when it is determined that there is an object approaching the vehicle (step B7; Yes), the acoustic direction comparison unit 21 determines the arrival direction of the sound of the approaching object (step B8). Then, the approach direction and alerting are displayed on the output unit 18 (step B9).

  Whether there is an approaching object or not (step B7; No), the averaging processing unit 14 averages the microphones 1a, 1b, 1c, and 1d corresponding to the vehicle state at that time. The vehicle sound and the current vehicle sound are weighted and averaged, and the storage of the vehicle sound-vehicle state comparison storage unit 15 is updated as an averaged vehicle sound corresponding to the vehicle state (step B10). The averaged vehicle sound other than the vehicle state at that time is not updated at that time.

  In the present embodiment, since a plurality of acoustic signal collecting means are provided and the direction of arrival of sound can be determined and displayed, more accurate information can be given to the driver. There is an effect that the driver can easily perform the avoidance operation and the danger prevention operation. Further, not only the audio signal but also other sounds in the vehicle are suppressed from the acoustic signal, so that the presence of an object approaching the vehicle can be determined more accurately.

  Next, a modification of the second embodiment will be described. FIG. 8 is a block diagram illustrating a different example of the second embodiment. In the vehicle exterior sound processing apparatus 100 of FIG. 8, the storage unit 13, the averaging processing unit 14, the vehicle sound comparison unit 16, and the approach determination unit 17 of FIG. The vehicle exterior sound processing apparatus 100 of FIG. 8 includes an ultrasonic obstacle detection device 36 and an image obstacle detection device 37.

  The microcomputer 30 includes a control unit 31, a main storage unit 32, an external storage input / output unit 33 and an input / output unit 34. The main storage unit 32, the external storage input / output unit 33, and the input / output unit 34 are all connected to the control unit 31 via the internal bus 35. In the configuration of FIG. 8, the vehicle sound-vehicle state comparison storage unit 15 is an external storage unit of the microcomputer.

  The control unit 31 of the microcomputer is composed of a CPU (Central Processing Unit) or the like, and receives an acoustic signal according to a program stored in an external storage unit, and performs comparison with vehicle sound, approach determination, and averaging processing. .

  The main storage unit 32 includes a RAM (Random-Access Memory) or the like, and is used as a work area for the control unit 31.

  The external storage unit including the vehicle sound-vehicle state comparison storage unit 15 includes a flash memory, a hard disk, a DVD (Digital Versatile Disc), a DVD-RAM (Digital Versatile Disc Random-Access Memory), and a DVD-RW (Digital Versatile Disc Rewritable). A program for causing the control unit 31 to perform the above processing is stored in advance, and in accordance with instructions from the control unit 31, this program and other data used by the program are stored in the control unit 31. The data supplied from the control unit 31 is stored. The external storage unit includes a vehicle sound-vehicle state comparison storage unit 15, supplies an averaged vehicle sound corresponding to the vehicle state, and updates a newly averaged vehicle sound according to an instruction from the control unit 31. And remember.

  The input / output unit 34 includes a serial interface, a parallel interface, or a LAN (Local Area Network) interface. The control unit 31 inputs acoustic signals from the vehicle interior sound suppression units 11 a, 11 b, 11 c, and 11 d through the input / output unit 34, and outputs data to be displayed on the output unit 18. The control unit 31 also inputs obstacle approach determination information from the ultrasonic obstacle detection device 36 and the image obstacle detection device 37 via the input / output unit 34.

  The ultrasonic obstacle detection device 36 includes an ultrasonic detector 36a and an ultrasonic approach determination unit 36b. The ultrasonic detector 36a detects the ultrasonic wave reflected from the object by emitting an ultrasonic wave, and the ultrasonic approach determination unit 36b determines the direction and distance of the object. If there is an approaching object as a result of the approach determination, the ultrasonic failure detection device 36 notifies the microcomputer 30 of the azimuth and distance.

  The image obstacle detection device 37 captures an image outside the vehicle and converts it into image data, an image processing unit 37b that processes the image and identifies an object, and an image that recognizes an approaching object as an obstacle. It is comprised from the obstruction approach determination part 37c. The image obstacle detection device 37 makes an approach determination based on, for example, a change in focal length when focusing on an automatically photographed object and a change in the size of the recognized object. If there is an approaching object as a result of the approach determination, the direction and distance are notified to the microcomputer 30.

  The control unit 31 of the microcomputer 30 can make the determination by comparing the approaching object determined from the acoustic signal with the approaching object determination result of the ultrasonic obstacle detection device 36 or the image obstacle detection device 37. Since the approaching object determination in the ultrasonic obstacle detection device 36 and the image obstacle detection device 37 is performed in a range where the ultrasonic wave and light are not blocked, the approaching object determined from the acoustic signal is the ultrasonic obstacle detection device. 36 and the image obstacle detection device 37 may not make an approach determination. However, for an object captured by ultrasound or an image, the approaching object determined from the acoustic signal is verified. As a result, the approaching object can be determined more accurately.

  In the second embodiment, in the exterior sound processing apparatus 100, the address generation unit 10, the interior sound suppression units 11a, 11b, 11c, and 11d, the interior sound processing unit 12, the storage unit 13, the averaging processing unit 14, and the vehicle sound comparison The part 16 and the approach determination part 17 can be configured entirely or partly by a DSP (Digital Signal Processor). That is, the DSP may include the address generation unit 10, the interior sound suppression units 11a, 11b, 11c, and 11d, and the microcomputer 30.

  Since each process is described in a program by using a microcomputer or a DSP, it is possible to change parameters such as time interval adjustment and the number of times of approach determination, and it is easy to deal with different vehicles. .

(Embodiment 3)
Still another embodiment 3 of the present invention will be described with reference to FIGS. FIG. 9 is a block diagram of the vehicle exterior sound processing apparatus 100 according to the third embodiment. The vehicle exterior sound processing apparatus 100 of FIG. 9 has a configuration in which a specific sound storage unit 22 and a specific sound comparison unit 23 are added to the vehicle exterior sound processing apparatus (FIG. 1) of the first embodiment.

  The specific sound storage unit 22 includes a memory or the like, and stores information on specific sounds that have an influence on the traveling of the vehicle such as sounds of emergency vehicles such as ambulances, fire engines, and police cars, and alarm sounds for crossings. Information on these specific sounds is collected and set in advance. The specific sound information can be digitized time axis information or frequency information.

  The specific sound comparison unit 23 includes, for example, a multiplier and an integrator. The specific sound comparing unit 23 compares the sound signal collected by the microphone 1 and the vehicle sound averaged with the vehicle sound and the specific sound stored in the specific sound storage unit 22 to specify the sound signal. Determine if sound is included. For example, it can be determined that the sound signal includes the specific sound when the value obtained by multiplying the sound signal and the specific sound for each frequency and integrating the multiplied result by the frequency is equal to or greater than a predetermined value. The comparison between the sound signal and the specific sound may be performed by pattern matching with the time axis information, or by comparing the spectrum with the frequency information and checking whether the frequency component of the specific sound is included in proportion. May be.

  FIG. 10 is a schematic diagram illustrating an example of how a specific sound is detected. FIG. 10A shows an acoustic signal including a specific sound. FIG. 10B shows a sound obtained by subtracting the averaged vehicle sound corresponding to the vehicle state at that time from the acoustic signal. FIG. 10C shows frequency information of a specific sound. The specific sound in FIG. 10 (c) is composed of two single sounds, for example, a sound like an ambulance siren. In the case of FIG. 10, the sound ((b) of FIG. 10) obtained by subtracting the averaged vehicle sound from the acoustic signal includes a component that is proportionally reduced from the specific sound ((c) of FIG. 10). It can be determined that a specific sound is included.

  The specific sound may not be a constant continuous sound, such as an ambulance siren or a crossing warning sound. Therefore, the specific sound comparison unit 23 performs comparison at time intervals such that all frequency components representing the characteristics of the specific sound are included. For example, if the acoustic signal is processed at 100 millisecond intervals, the acoustics at 10 consecutive intervals (100 milliseconds / 10 times = 1 second) so that two single sounds of the ambulance siren are included on average. Compare signals by averaging.

  In comparison with the specific sound, it is necessary to note that the frequency of the specific sound is shifted by the Doppler effect according to the relative speed between the host vehicle and the approaching object. The sound of an approaching object has a higher frequency, and the sound of an object moving away has a lower frequency. Therefore, the frequency does not exactly match the stored specific sound. The specific sound comparing means shifts and compares the frequencies on the assumption that a frequency shift occurs within the range of the assumed relative velocity. It is also possible to determine the approach by calculating backward from the frequency shift amount.

  Next, the operation of the vehicle exterior sound processing apparatus 100 of FIG. 9 will be described with reference to FIG. FIG. 11 is a flowchart for explaining the operation of the vehicle exterior sound processing apparatus 100 according to the third embodiment. In FIG. 11, steps C1 to C5 are the same as steps A1 to A5 in FIG.

  In the present embodiment, after the vehicle sound comparison, the acoustic signal is compared with the specific sound (step C6). Here, since there may be a plurality of specific sounds, each specific sound is compared.

  Next, as in step A6 in FIG. 1, based on the comparison result, the approach determination unit 17 determines whether there is an object approaching the vehicle (step C7). When there is an approaching object (step C8; Yes), the case is further divided according to whether it is a specific sound (step C9). When it is a specific sound (step C9; Yes), the information of a specific sound is displayed on the output part 18 (step C10). As a display method, for example, “Ambulance is approaching” may be displayed by voice, or the specific sound itself may be reproduced from the speaker 19. Moreover, the display of the display 20 can be used together.

  When it is not a specific sound (step C9; No), a warning display is performed on the output unit 18 (step C11). Whether there is an approaching object or not (step C8; No), the averaging processing unit 14 weights the averaged vehicle sound corresponding to the vehicle state at that time and the current vehicle sound. Then, the storage of the vehicle sound-vehicle state comparison storage unit 15 is updated as an averaged vehicle sound corresponding to the vehicle state (step C12). The averaged vehicle sound other than the vehicle state at that time is not updated at that time.

  According to the third embodiment, the specific sound set in advance and the acoustic signal are compared to determine whether or not the specific sound is included, so that the driver quickly performs the operation according to the specific sound. be able to.

  Next, a modification of the third embodiment will be described. FIG. 12 is a block diagram illustrating a different example of the third embodiment. The vehicle exterior sound processing apparatus 100 of FIG. 12 has a configuration in which a specific sound storage unit 22 and a specific sound comparison unit 23 are further added to the vehicle exterior sound processing apparatus 100 of FIG. In the vehicle exterior sound processing apparatus 100 of FIG. 12, the specific sound and the acoustic signal are compared to determine whether or not the specific sound is included, and to display the approaching direction at the same time. When an object that emits a specific sound approaches, the sound source of the specific sound approaches and the approaching direction can be displayed. For example, “Ambulance approaches from the right rear” can be displayed. As a result, the driver can quickly perform more accurate movement. As a result, the vehicle traveling safety is improved and the vehicle traffic is smooth.

It is a block diagram of the vehicle exterior sound processing apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the example of the structure of a vehicle sound-vehicle state comparison memory | storage part. It is a schematic diagram which shows the example of a mode that the acoustic information difference is expanding. 3 is a flowchart showing the operation of the first embodiment. 6 is a plan view showing an example of arrangement of acoustic signal collecting means according to Embodiment 2. FIG. 6 is a block diagram of a vehicle exterior sound processing device according to Embodiment 2. FIG. 10 is a flowchart showing the operation of the second embodiment. FIG. 10 is a block diagram illustrating a different example of the second embodiment. FIG. 6 is a block diagram of a vehicle exterior sound processing device according to a third embodiment. It is a schematic diagram which shows the example of a mode that a specific sound is detected. 10 is a flowchart showing the operation of the third embodiment. FIG. 10 is a block diagram illustrating a different example of the third embodiment.

Explanation of symbols

1, 1a, 1b, 1c, 1d microphone (acoustic signal collecting means)
4 Vehicle state detection unit (vehicle state detection means)
7, 7a, 7b, 7c, 7d A / D converter
9 A / D converter 11, 11a, 11b, 11c, 11d In-car sound suppression unit (audio signal suppression means)
13 Memory unit
14 Averaging processor
15 Vehicle sound-vehicle state comparison storage unit
16 Vehicle sound comparison part
17 Approach judgment part
19 Speaker (display)
20 Display
21 Acoustic direction comparison part (acoustic direction comparison means)
22 Specific sound storage unit (specific sound storage means)
23 Specific sound comparison unit (specific sound comparison means)

Claims (6)

Acoustic signal collecting means provided in the vehicle for collecting sounds outside the vehicle;
Vehicle state detecting means for detecting a vehicle state that is an operating state of each device of the vehicle;
A storage unit for storing the acoustic signal collected by the acoustic signal collecting means in association with the vehicle state when the acoustic signal is collected;
Vehicle sound-vehicle state comparison storage means for storing information obtained by averaging the stored acoustic signals for each vehicle state over a predetermined period in association with the vehicle state;
Vehicle sound comparison means for comparing the acoustic signal collected by the acoustic signal collection means during traveling of the vehicle and the averaged information corresponding to the vehicle state when the acoustic signal was collected;
As a result of the vehicle sound comparison means comparing the acoustic signal during vehicle travel with the averaged information corresponding to the vehicle state at that time, the acoustic signal during vehicle travel is greater than the averaged information and sequentially. An approach determining means for determining that there is an object approaching the vehicle when it becomes larger;
A vehicle exterior sound processing apparatus. A plurality of acoustic signal collecting means;
Acoustic azimuth comparison means for comparing acoustic signals collected by the plurality of acoustic signal collection means;
With
The acoustic azimuth comparing means compares the acoustic signals collected by the plurality of acoustic signal collecting means and determines the arrival direction of the approaching object when the approach determining means determines that there is an object approaching the vehicle. The vehicle exterior sound processing apparatus according to claim 1, wherein the determination is made. Specific sound storage means for storing acoustic information of the specific sound outside the vehicle;
Specific sound comparison means for comparing the sound of the approaching object with the specific sound;
A display for displaying the approach of the sound source of the specific sound;
Further comprising
The specific sound comparing means, when the sound of the approaching object and the specific sound stored in the specific sound storage means match, the approach of the sound source of the specific sound corresponding to the matching specific sound The vehicle exterior sound processing apparatus according to claim 1, wherein the sound is displayed on a display.   The audio signal suppression means which suppresses the acoustic signal of the audio apparatus from the acoustic signal collected by the acoustic signal collection means to make the acoustic signal external to the vehicle when the vehicle is equipped with an audio device. The vehicle exterior sound processing device according to 1.   2. The vehicle exterior sound processing apparatus according to claim 1, wherein the acoustic signal collected by the acoustic signal collecting means is digitized and processed as frequency information and / or time axis information.   As the operating state of each device of the vehicle, vehicle speed, accelerator opening, engine speed, acceleration / deceleration state, transmission state, steering steering angle, wiper operating state, air conditioner operating state, electric fan operating state, window opening / closing state The vehicle exterior sound processing device according to claim 1, comprising any combination of a horn operating state and a type of tire mounted on the vehicle.

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