JP2019200091A - Positioning system, air conditioning system, terminal device, location estimation device, location estimation method, sound wave output method and program - Google Patents

Abstract

To provide a positioning system that estimates a location of a sound source in a space.SOLUTION: A positioning system comprises: a terminal device that outputs a sound wave of a different frequency for each of a plurality of continuous time sections; a plurality of microphones; and a location estimation device. The location estimation device is configured to detect an arrival time of the sound wave of a prescribed frequency set for the second and subsequent time sections out of the plurality of time sections, and estimate an output location of the sound wave on the basis of a time difference between the arrival times of the sound waves detected by each of the plurality of microphones.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a positioning system, an air conditioning system, a terminal device, a position estimation device, a position estimation method, a sound wave output method, and a program.

  When air-conditioning a space such as an office, the room temperature is often controlled to be uniform. In contrast, for example, a method of performing air conditioning control such as room temperature for an area where a user exists is provided. When performing such control, the air conditioning system needs to accurately estimate the position where the user exists. For example, microphones that detect sound are attached to four places on the ceiling, the sound is output from a smartphone or the like that the user possesses, and a method such as TDOA (Time Difference of Arrival) is used based on the difference in arrival time of the sound. A method of estimating the position where the user exists can be considered.

  In Patent Document 1, in the space where there are a plurality of users, the position of each individual can be specified based on the radio field intensity of the environment setting terminal held by the users or the TDOA measurement, and each air conditioning request can be made. An air-conditioning control apparatus that performs control that satisfies as much as possible is disclosed.

Japanese Patent No. 4867836

  However, the waveform of the sound emitted by the user using a smartphone or the like has a property that the amplitude gradually increases. Therefore, on the sensor side, there is a difference in the arrival time of the sound depending on which magnitude the amplitude is determined to have detected the sound. In a method such as TDOA, position estimation is performed based on differences in arrival times of sounds at a plurality of positions. However, if the arrival times of sounds cannot be accurately detected, the accuracy of position estimation may be reduced.

  Therefore, an object of the present invention is to provide a positioning system, an air conditioning system, a terminal device, a position estimation device, a position estimation method, a sound wave output method, and a program that can solve the above-described problems.

  According to one aspect of the present invention, a positioning system includes a terminal device including a sound wave output unit that outputs a continuous sound wave by changing the frequency to a different frequency for each of a plurality of time intervals, and a plurality of sound waves that are collected. A sensor and a position estimation device, wherein the sound wave output unit outputs a sound wave having a predetermined first frequency in the first time interval, and outputs the sound wave in the time interval immediately before the first time interval. A sound wave having a predetermined second frequency is output, and the position estimating device detects an arrival time detecting unit that detects an arrival time of the sound wave having the first frequency, and a sound wave collected by each of the plurality of sensors. A position estimation unit that estimates an output position of the sound wave based on a time difference between the arrival times detected by the arrival time detection unit.

  According to an aspect of the present invention, the sound wave output unit has the first frequency after the elapse of time from the start of the sound wave output until the amplitude of the sound pressure of the sound wave settles within a predetermined range. The sound wave is output.

  According to one aspect of the present invention, the time during which the amplitude change is within a predetermined range is 50 msec or more and 200 msec or less.

  According to one aspect of the present invention, the difference between the first frequency and the second frequency is 1 KHz or more.

  According to an aspect of the present invention, the position estimation device further includes a filter that includes the first frequency and the second frequency in a pass band, and the arrival time detection unit includes the first frequency, The arrival time is detected based on a difference from the second frequency.

  According to an aspect of the present invention, the position estimation device further includes a filter that includes the first frequency in a passband and does not include the second frequency in a passband, and the arrival time detection unit includes the first frequency The time when the sound wave of one frequency is detected is defined as the arrival time.

  According to an aspect of the present invention, the sound wave output unit outputs sound waves in a predetermined frequency band between 10 kHz and 20 kHz.

  According to an aspect of the present invention, in the positioning system, when the position estimation device fails to estimate the arrival time of the sound wave or to estimate the output position of the sound wave, a communication unit that outputs an error signal; Further prepare.

  According to one aspect of the present invention, an air conditioning system includes any one of the positioning systems described above, and performs air conditioning on the output position of the sound wave estimated by the position estimation device.

  According to an aspect of the present invention, a terminal device is a terminal device that outputs sound waves to notify the position of the device itself, and outputs continuous sound waves that are changed to different frequencies for each of a plurality of time intervals. A sound wave output unit.

  According to the aspect of the present invention, the position estimation device outputs a continuous sound wave output at a different frequency for each of a plurality of time sections to the second and subsequent time sections among the plurality of time sections. An arrival time detection unit that detects the arrival time of the sound wave of a predetermined first frequency, and the sound wave that each of a plurality of sensors collects, based on the time difference of the arrival time detected by the arrival time detection unit A position estimation unit that estimates an output position of the sound wave.

  According to an aspect of the present invention, the position estimation method includes: a step in which a plurality of sensors collect continuous sound waves output at different frequencies for each of a plurality of continuous time intervals; A step of detecting an arrival time of the sound wave having a predetermined first frequency set for the second and subsequent time intervals, and a step of detecting the arrival time of the sound wave detected by each of the plurality of sensors. Estimating the output position of the sound wave based on the detected time difference of the arrival times.

  According to one aspect of the present invention, the sound wave output method is a sound wave output method for notifying the output position of a sound wave, and outputs a continuous sound wave by changing it to a different frequency for each of a plurality of time intervals. The sound wave having a predetermined frequency is output after a lapse of time from the start of the sound wave output until the amplitude of the sound pressure of the sound wave is set within a predetermined range.

  According to one aspect of the present invention, the program outputs a continuous sound wave by changing the frequency to a different frequency for each of a plurality of time intervals, and the amplitude of the sound pressure of the sound wave from the start of the sound wave output. It is made to function as a means for outputting the sound wave having a predetermined frequency after elapse of time until settling within a predetermined range.

  According to one aspect of the present invention, a program is set for a second and subsequent time intervals of a plurality of time intervals for a continuous sound wave output at a different frequency for each of a plurality of time intervals. The means for detecting the arrival time of the sound wave having a predetermined first frequency, and the sound wave detected by each of a plurality of sensors, based on the time difference of the arrival time detected by the means for detecting the arrival time. It functions as a means for estimating the output position.

  According to the present invention, it is possible to accurately estimate the position of a sound source.

It is a figure showing an example of an air-conditioning system in a first embodiment of the present invention. It is a figure which shows the example of arrangement | positioning of the microphone in 1st embodiment of this invention. It is a figure explaining the sound signal in 1st embodiment of this invention. It is a figure explaining the detection method of the arrival time of the sound in 1st embodiment of this invention. It is a flowchart which shows an example of the position estimation process of the sound source in 1st embodiment of this invention. It is a flowchart which shows an example of the air-conditioning control in 1st embodiment of this invention. It is a figure which shows an example of the air conditioning system in 2nd embodiment of this invention. It is a figure which shows an example of the relationship between the frequency of the sound and the pass band of a filter in 2nd embodiment of this invention. It is a figure explaining the detection method of the arrival time of the sound in 2nd embodiment of this invention. It is a flowchart which shows an example of the position estimation process of the sound source in 2nd embodiment of this invention. It is a figure which shows an example of the hardware constitutions of the position estimation apparatus in each embodiment of this invention, and a terminal device.

<First embodiment>
Hereinafter, the air-conditioning system by 1st embodiment of this invention is demonstrated with reference to FIGS.
Drawing 1 is a figure showing an example of an air-conditioning system in a first embodiment of the present invention.
As illustrated, the air conditioning system includes an air conditioner 10, a terminal device 40, and microphones M1 to M4. The air conditioner 10 includes a control device 20. The control device 20 controls the operation of the air conditioner 10. The control device 20 has a function of controlling the air conditioner 10 to perform air conditioning for a part of the space w. The control device 20 includes a position estimation device 30. The position estimation device 30 estimates the position where the sound s is emitted based on the sound s emitted by the terminal device 40. For example, the control device 20 performs air conditioning control on the position estimated by the position estimation device 30.

  The terminal device 40 includes a sound wave output unit 41. The sound wave output unit 41 continuously outputs sound waves s having different frequencies for each of a plurality of continuous time intervals in order to notify the air conditioner 10 of the position of the user who operates the terminal device 40. The terminal device 40 is an information processing device such as a smartphone, for example. As the frequency of the sound s output by the sound wave output unit 41, a frequency having a low noise level is selected so as not to be mixed with various existing noises. For example, a sound of 10 kHz or less is used as an audible sound or a wind noise accompanying an air conditioner operation. Moreover, the upper limit of the frequency which a general smart phone can output is about 20 kHz. Therefore, it is desirable to select the frequency of the sound s from the range of 10 to 20 kHz. Furthermore, the frequency of the sound s is preferably set to avoid the switching frequency of the inverter provided in the air conditioner 10 (for example, around 17 kHz). Also, since the audible range may be uncomfortable for humans, the frequency of the sound s may be set avoiding the audible range (if the frequency is in the range of 10 to 20 kHz, the lower the frequency, the easier to hear). . In addition, there is a limit to the output near 20 kHz that is the upper limit, and the amplitude tends to attenuate as the frequency becomes higher. For example, it is preferable to avoid the vicinity of 20 kHz. Taking these various conditions into consideration, the frequency of the sound s is set in the vicinity of 15 kHz, for example. As will be described later, the sound output from the sound wave output unit 41 has a property that the amplitude gradually increases from the start of sound output until the amplitude of the waveform settles within a predetermined range. The sound wave output unit 41 outputs a series of sounds s whose frequencies are changed in the time interval T1 until the amplitude increases and the subsequent time interval T2. The frequency of the sound s in the time interval T1 is α1, and the frequency of the sound s in the time interval T2 is α2.

The terminal device 40 and the position estimation device 30 are configured to be able to communicate with each other by communication means such as a wireless LAN, Bluetooth (registered trademark), and ultrasonic communication.
The microphones M <b> 1 to M <b> 4 are sensors that collect the sound s output from the terminal device 40.

  The position estimation device 30 estimates the position of the sound source (terminal device 40) based on the difference in time at which the sound s output from the terminal device 40 reaches each of the microphones M1 to M4. The control device 20 performs air conditioning control on the position estimated by the position estimation device 30.

Next, the function of the position estimation device 30 will be described. The position estimation device 30 includes an amplifier 31, a filter 32, a comparator 33, and a microcomputer 34.
The amplifier 31 acquires analog sound signals obtained by the microphones M1 to M4 collecting the sound s and converting them into electric signals for each of the microphones M1 to M4, and amplifies the respective amplitudes. The amplifier 31 outputs the amplified analog sound signal (analog sound signal for each of the microphones M1 to M4) to the filter 32.
The filter 32 attenuates unnecessary high frequency components and low frequency components of the analog sound signal acquired from the amplifier 31 and outputs an analog sound signal in a predetermined frequency band to the comparator 33. The filter 32 is configured to pass the frequencies α1 and α2 of the sound s output from the terminal device 40.
The comparator 33 compares the amplitude of the analog sound signal of the sound s output from the filter 32 with a predetermined threshold, and outputs “1” if the amplitude of the analog sound signal exceeds the threshold. The amplitude of the analog sound signal is If it is below the threshold, “0” is output. Here, the threshold value is a value for determining whether or not the sound s output from the terminal device 40 has arrived. The comparator 33 outputs a pulse signal “0” or “1” to the microcomputer 34.

The microcomputer 34 is a computer provided with a CPU (central processing unit). The microcomputer 34 includes an arrival time detection unit 35, a position estimation unit 36, and a communication unit 37.
The arrival time detection unit 35 detects the time (arrival time) when the sound s reaches each of the microphones M1 to M4. Specifically, the arrival time detection unit 35 sets the time when the sound s having the frequency α2 is detected as the arrival time of the sound s.

The position estimation unit 36 uses a microphone (for example, the microphone M1) of the microphones M1 to M4 as a reference, the time when the reference microphone M1 detects the sound s, and the other three microphones M2 to M4 generate the sound s. That is, the time difference (arrival time difference) between the time when the sound s reaches the microphone M1 and the time when the sound s reaches the microphones M2 to M4 is calculated. The position estimation unit 36 estimates the position where the sound s is output (position where the user exists) based on the calculated arrival time difference.
The communication unit 37 communicates with the terminal device 40 and transmits the result of success or failure of the arrival time estimation process and the position estimation process.

Next, an example of the position estimation method in this embodiment will be described with reference to FIG.
FIG. 2 is a diagram illustrating an arrangement example of microphones in the first embodiment of the present invention.
FIG. 2 shows an arrangement example of the microphones M1 to M4. The microphones M <b> 1 to M <b> 4 are arranged on the ceiling of the space w so that, for example, each of the microphones M <b> 1 to M <b> M has a square apex centered on the center of the air outlet of the air conditioner 10.
The position estimation unit 36 estimates the position of the terminal device 40 based on the difference in time (arrival time difference) when the microphones M1 to M4 detect the sound s. For estimating the position, a known method such as TDOA (Time Difference Of Arrival) can be used. For example, the coordinates of the microphones M1 to M4 are (A1, B1, C1), (A2, B2, C2), (A3, B3, C3), (A4, B4, C4), respectively, and the coordinates of the position of the terminal device 40 (X, y, z), and the difference between the arrival time of the sound s to the microphone M1 and the arrival time of the sound s to the microphones M1 to M4 is t1, t2, t3. Assuming t4, where d is the distance between the terminal device 40 and the microphone M1, and c is the speed of sound, the following simultaneous equations are obtained.
(X−A1) ² + (y−B1) ² + (z−C1) ² − (d + c · t1) ² = 0
(X−A2) ² + (y−B2) ² + (z−C2) ² − (d + c · t2) ² = 0
(X−A3) ² + (y−B3) ² + (z−C3) ² − (d + c · t3) ² = 0
(X−A4) ² + (y−B4) ² + (z−C4) ² − (d + c · t4) ² = 0
According to TDOA, the position of the terminal device 40 can be calculated by solving the above equation using approximate calculation such as Newton-Raphson method. Thus, in order to estimate the sound source position, the arrival time difference between the microphones must be accurately calculated. For this purpose, it is necessary to be able to detect accurate arrival times at the microphones M1 to M4. Next, the property of the sound s output by the terminal device 40 (sound wave output unit 41) such as a smartphone will be described.

FIG. 3 is a diagram for explaining a sound signal in the first embodiment of the present invention.
FIG. 3A shows an example of an analog sound signal emitted from the terminal device 40. The amplitude of the sound pressure of an analog sound signal output from a smartphone or the like (when the amplitude falls within a predetermined range) varies as shown in FIG. Therefore, in order to detect the arrival of the sound s, a method may be considered in which a threshold is set for the sound pressure, and when this threshold is exceeded a predetermined number of times, that time is determined as the arrival time of the sound s.
FIG. 3B shows a change over time in the amplitude of the sound pressure of the sound s detected by the microphone M1 or the like. FIG. 3B shows that the sound s output from the smartphone or the like gradually increases in amplitude of the sound pressure from the start of output, and the waveform has a trumpet shape. When the waveform changes in this way, the arrival time changes depending on how the sound pressure threshold for determining the arrival of the sound s is provided, and the determination of the detection of the sound s becomes unclear. Further, since the way in which the sound pressure rises (inclination) and the sound pressure peak (amplitude peak) differ depending on the model of the smartphone and the frequency of the sound s, the arrival determination of the sound s cannot be performed with one threshold value. Therefore, in the present embodiment, the arrival time of the sound s is estimated using the fact that it takes a certain time until the waveform of the sound s rises. Next, the arrival time estimation method of this embodiment will be described with reference to FIG.

FIG. 4 is a diagram illustrating a method for detecting the arrival time of sound in the first embodiment of the present invention.
First, the sound wave s output from the terminal device 40 will be described. The upper diagram of FIG. 4 shows the sound pressure waveform of the sound s.
The sound wave output unit 41 of the terminal device 40 outputs sound waves having the frequency α1 during the time interval T1 from the start of output of the sound s. Here, the length of the time section T1 is, for example, about 100 msec. The length of the time interval T1 is set as a length corresponding to the time until the amplitude of the sound s gradually increases and settles within a predetermined range. Since the length of the time section T1 depends on the type of terminal device 40, the frequency α, and the like, it is appropriately set between 50 msec and 200 msec depending on the length until the amplitude of the sound s is settled. Further, the length of the time interval T1 may be set as a length having a little margin than the time required for the amplitude of the sound s to be amplified and settled. The frequency α1 is, for example, about 16 KHz.

  When the time interval T2 passes through the time interval T1 from the output of the sound s, the sound wave output unit 41 changes the frequency from α1 to α2 while outputting the sound s. The frequency α2 is about 15 KHz, for example. In order to discriminate between the sound wave having the frequency α1 and the sound wave having the frequency α2, it is preferable that the frequency α1 is separated from the frequency α2 by 1 KHz or more. For example, the sound wave output unit 41 outputs the sound s at the frequency α2 during the time interval T2 set to a length approximately equal to the length of the time interval T1.

Next, the detection process of the sound s by the arrival time detection unit 35 will be described.
Pth in the upper diagram of FIG. 4 is a threshold when the comparator 33 generates a pulse signal. The comparator 33 outputs “1” if the amplitude of the sound s exceeds the threshold Pth, and outputs “0” if it is equal to or less than the threshold Pth. The lower diagram of FIG. 4 shows a graph of the pulse signal output by the comparator 33 for the sound s in the upper diagram of FIG. During the time interval T0, although the sound s has actually reached, the amplitude of the sound s is small, so the comparator 33 outputs “0” to the microcomputer 34. Thereafter, when the maximum value of the amplitude of the sound s exceeds the threshold value Pth, the comparator 33 alternately outputs “0” and “1” in accordance with the period in which the amplitude level increases or decreases the threshold value Pth.

  In the microcomputer 34, when the arrival time detection unit 35 acquires the pulse signal, the arrival time detection unit 35 detects the arrival of the sound s based on a cycle in which “0” and “1” change. As shown in the figure, the period (or pulse width) of the pulse signal output from the comparator 33 varies between the time interval T1 and the time interval T2 according to the frequency of the sound s. The arrival time detector 35 detects the time t3 when the cycle of the pulse signal changes as the arrival time of the sound s. For example, when the arrival time detection unit 35 obtains a signal in which “0” and “1” change at a constant period from a state in which the pulse signal continues “0”, the period is calculated and stored. The arrival time detection unit 35 compares the stored cycle with the cycle in which “0” and “1” obtained from the comparator 33 change. The arrival time detection unit 35 generates a sound when the period of the acquired signal is X times (for example, three times) continuously and is different from the stored period (period at T1) (the difference in period is equal to or greater than a predetermined threshold). It is determined that s has arrived, and the time t3 that is a predetermined time later than the time t4 at which the sound s has been determined is defined as the arrival time of the sound s. In the example of FIG. 4, the predetermined time is a pulse period r0 × (X−1) + pulse width r1 after change. Alternatively, the arrival time detection unit 35 sets the period of the pulse signal of the time interval T1 and the time interval T2 set in advance based on the frequency α1 of the sound s in the time interval T1 and the frequency α2 of the sound s in the time interval T2. The period of the pulse signal acquired from the comparator 33 is compared, and if the period of the pulse signal acquired from the comparator 33 is within a range that can be regarded as the period of the pulse signal in the time interval T2, it is determined that the sound s has arrived. Then, similarly to the above example, the time t3 when the pulse signal in the time interval T2 is first detected may be calculated, and the time t3 may be set as the arrival time of the sound s. Alternatively, the arrival time detector 35 may similarly estimate the arrival time of the sound s by detecting a change in the pulse width r1 instead of the period of the pulse signal.

  Thus, in this embodiment, after the terminal device 40 has settled the time interval T1 in which the amplitude of the waveform increases in accordance with the time required for the rising of the waveform of the sound s (for example, 100 msec), and the change in amplitude. The sound s having a different frequency is output in the time interval T2. Then, the position estimation device 30 estimates the time t3 at which the frequency changes, and uses the estimated time as the arrival time of the sound s to the microphone M1 or the like. Thus, by providing a reference for detecting the completion time of the rise of the waveform, the threshold value for the magnitude of the amplitude simply due to the property of the sound s that the amplitude gradually changes from the start of the output and the amplitude varies. When the sound signal exceeding the threshold is detected, the uncertainty of determination in the case where it is determined that the sound s has arrived can be eliminated.

FIG. 5 is a flowchart showing an example of a sound source position estimation process in the first embodiment of the present invention.
The flow of the position estimation process according to this embodiment will be described with reference to FIG. As a premise, it is assumed that the position estimation unit 36 stores position information of the microphones M1 to M4. In addition, the terminal device 40 may output a program that outputs the frequency α1 during the time interval T1 and the frequency α2 during the time interval T2 from the start of output of the sound s, or outputs such a sound s by reproduction. An audio file (wav file or the like) in a predetermined format is stored, and the sound wave output unit 41 outputs the sound s from the speaker of the terminal device 40 by executing the program or playing the audio file. Is done.

  First, the user operates the terminal device 40 to start outputting a sound s output at a different frequency for each of a plurality of time intervals. The microphones M1 to M4 collect the sound s (step S11). When the microphones M <b> 1 to M <b> 4 pick up the sound s, the microphones M <b> 1 to M <b> 4 convert the sound s into an electric signal and output an analog sound signal of the sound s to the amplifier 31. The amplifier 31 amplifies the analog sound signal of the sound s output from the microphones M <b> 1 to M <b> 4 and outputs the amplified signal to the filter 32. The filter 32 extracts a frequency in a predetermined pass band including α1 and α2 from the four analog sound signals after amplification, and outputs the extracted frequency to the comparator 33. The comparator 33 converts each of the four analog sound signals for the sound s collected by the microphones M1 to M4 output from the filter 32 into a pulse signal based on a predetermined threshold, and converts the pulse signal into the microcomputer 34. Output to.

  In the microcomputer 34, the arrival time detection unit 35 acquires four pulse signals and detects a change in the frequency of the sound s (step S12). Specifically, as described with reference to FIG. 4, the arrival time detection unit 35 changes the cycle of the pulse signal corresponding to the change of the frequency of the sound s from α1 to α2 for each of the four pulse signals ( Or change in pulse width). For example, the arrival time detection unit 35 determines that the cycle of the pulse signal has changed when the cycle of the pulse signal changes and the cycle continues for a predetermined number of times or more. The arrival time detection unit 35 detects and stores the time, the pulse period, the pulse width, and the like when it is determined that the period of the pulse signal has changed.

Next, the arrival time detector 35 estimates the arrival time of the sound s to each of the microphones M1 to M4 (step S13). For example, the arrival time detection unit 35 uses a time, a pulse period, a pulse width, etc., determined that the period of the pulse signal stored in step S12 has changed, and a predetermined time from a time when it has been determined that the period of the pulse signal has changed. The time that goes back in time is calculated, and the calculated time is estimated as the arrival time of the sound s. The arrival time detection unit 35 outputs the estimated arrival times (four) of the sound s to the microphones M1 to M4 to the position estimation unit 36.
The position estimation unit 36 determines, for example, the arrival time difference of the sound s from the microphone M1 and the microphone M2 from the arrival time of the sound s to the microphones M1 to M4, the arrival time difference of the sound s from the microphone M1 to the microphone M3, the microphone The arrival time difference of the sound s to M1 and the microphone M4 is calculated, and the position of the sound source (terminal device 40) is estimated by TDOA (step S14).

Next, air conditioning control based on position estimation by the position estimation device 30 will be described.
FIG. 6 is a flowchart showing an example of air conditioning control in the first embodiment of the present invention.
First, the user operates the terminal device 40 to output a sound s having a predetermined frequency (step S21). In the air conditioner 10, the microphones M1 to M4 collect the sound s (step S22). The position estimation device 30 acquires a pulse signal based on the sound s output from the microphones M1 to M4, and estimates the arrival time and the sound source position. For example, when the period of the pulse signal is not within a predetermined range, or when a pulse signal for a certain period cannot be acquired, the arrival time detection unit 35 of the position estimation device 30 determines that reception has failed (step S23). No), the communication unit 37 transmits an error signal to the terminal device 40 (step S24). On the other hand, when the sound s can be normally received (step S23; Yes), the communication unit 37 transmits a signal indicating successful reception to the terminal device 40. The terminal device 40 notifies the user of successful reception by displaying a message notifying successful reception on the display or playing a sound. Alternatively, on the air conditioner 10 side, a sound may be emitted or an LED may be turned on to notify the user of successful reception. If the reception of the sound s is successful, the position estimation device 30 estimates the position of the sound source (step S25). The estimation method is as described with reference to FIGS.

  When the position estimation process is successful (step S26; Yes), the communication unit 37 transmits a signal indicating success in position estimation to the terminal device 40. The terminal device 40 displays a message informing the success of position estimation on the display or makes a sound. Alternatively, the user may be notified of the success of position estimation by sounding the air conditioner 10 or turning on the LED. When the position estimation device 30 succeeds in estimating the position, the control device 20 performs air conditioning control on the estimated position of the sound source (step S28). For example, the control device 20 performs control such as controlling the louver (not shown) of the air conditioner 10 to direct the wind direction to the estimated sound source position.

On the other hand, if the solution of the above simultaneous equations cannot be calculated, or if the calculated solution is abnormal (such as out of the range of the space w), the position estimation device 30 fails in the position estimation process. When the position estimation process fails (step S26; No), the position estimation device 30 transmits an error signal to the terminal device 40 (step S27).
When the error signal is received in step S24 or step S27, the terminal device 40 displays a message on a display or the like, sounds an audible sound notifying that reception or position estimation has failed, or turns on an LED lamp. Then, the user is notified of the error. After confirming these notifications, the user operates the terminal device 40 again to output the sound s (step S21). Thereafter, the above process is repeated until the position estimation is successful.

  According to the position estimation device 30 of the present embodiment, the sound s having the property that the amplitude of the sound pressure gradually increases with the output of the sound reaches the microphones M1 to M4 in an environment with various noises. The time can be detected with high accuracy. Thereby, the position of the sound source (user) with high accuracy can be estimated. Moreover, the control apparatus 20 can perform the air-conditioning control which makes object the area which a user desires by providing the position estimation apparatus 30. FIG.

  In the above description, the case where position estimation is performed for one output of the sound s from the terminal device 40 has been described as an example. However, in order to perform one position estimation, a series of sounds s ( During the time intervals T1 and T2, sounds output at the frequencies α1 and α2 may be output a plurality of times. In that case, the position estimation apparatus 30 performs position estimation with respect to the output position of the sound s every time the terminal apparatus 40 outputs the sound s, and estimates, for example, the average value of the estimation results as the position of the terminal apparatus 40 (user). You may do it. By determining a final estimated position based on a plurality of estimation results, it is possible to reduce the influence of variations in position estimation processing and improve the accuracy of position estimation.

<Second embodiment>
Hereinafter, an air conditioning system according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a diagram illustrating an example of an air conditioning system according to the second embodiment of the present invention.
Among the configurations according to the second embodiment of the present invention, the same components as those of the air conditioning system according to the first embodiment of the present invention are denoted by the same reference numerals, and description thereof is omitted. In the air conditioning system according to the second embodiment, the position estimation device 30 </ b> A includes an arrival time detection unit 35 </ b> A instead of the arrival time detection unit 35. The terminal device 40 </ b> A includes a sound wave output unit 41 </ b> A instead of the sound wave output unit 41.
Similar to the first embodiment, the sound wave output unit 41A has different frequencies of sound waves while the amplitude indicating the sound pressure increases (time interval T1 ′) and after the amplitude has settled within a predetermined range (time interval T2 ′). Is output. As an example, the sound wave output unit 41A outputs a sound wave having the frequency α1 ′ during the time interval T1, and outputs a sound wave having the frequency α2 during the time interval T2. Here, the relationship between the frequencies α1 (first embodiment), α1 ′, α2 and the passband of the filter 32 will be described with reference to FIG.

FIG. 8 is a diagram showing an example of the relationship between the sound frequency and the filter passband in the second embodiment of the present invention. FIG. 8 shows the gain (gain) for each frequency input to the filter 32.
As shown in the drawing, the frequency α1 (first embodiment) in the time interval T1 and the frequency α2 in the time interval T2 are both included in the passband of the filter 32. On the other hand, the frequency α1 ′ in the time interval T1 ′ of the second embodiment is not included in the passband of the filter 32. Therefore, in the second embodiment, the sound s does not pass through the filter 32 during the time interval T1 ′. Therefore, during the time interval T1 ′, the value of the pulse signal output from the comparator 33 is “0”.

The arrival time detection unit 35A, for example, outputs a sound when the output from the comparator 33 is constantly changed from "0" and "1" is added a predetermined number of times or continuously for a predetermined number of times. It is determined that s has reached. The arrival time detection unit 35A estimates the arrival time of the sound s as the arrival time of the sound s by a predetermined time after the determination that the sound s has arrived. In the first embodiment, the arrival time of the sound s is estimated based on the change of the period and the pulse width of the pulse signal. However, in the second embodiment, the arrival time detection unit 35A receives a signal having a value of “1”. The time acquired first is defined as the arrival time of the sound s. The arrival time detection unit 35A estimates the arrival time for each of the sounds s detected by the microphones M1 to M4 and outputs the four arrival times to the position estimation unit 36.
The position estimation unit 36 determines, for example, the arrival time difference of the sound s from the microphone M1 and the microphone M2 from the estimated value of the arrival time of the sound s to the microphones M1 to M4, and the arrival time of the sound s from the microphone M1 to the microphone M3. The difference, the arrival time difference of the sound s to the microphone M1 and the microphone M4, is calculated, and the position of the sound source (terminal device 40) is estimated by TDOA.

FIG. 9 is a diagram for explaining a method for detecting the arrival time of sound in the second embodiment of the present invention.
First, the sound wave s output from the terminal device 40 will be described. The upper diagram of FIG. 9 shows the waveform of the sound pressure of the sound s.
The sound wave output unit 41A of the terminal device 40 outputs a sound wave having a frequency α1 ′ during the time interval T1 ′ from the start of output of the sound s. Similar to the first embodiment, the length of the time interval T1 ′ is set based on the time required for the amplitude of the sound s to settle within a predetermined range (50 msec to 200 msec). Further, the frequency α1 ′ is not included in the pass band of the filter 32 as shown in FIG.

  When the time interval T2 ′ passes through the time interval T1 ′ from the output of the sound s, the sound wave output unit 41A changes the frequency from α1 ′ to α2 while outputting the sound s. The frequency α2 is, for example, about 15 KHz (similar to the first embodiment). For example, the sound wave output unit 41A outputs the sound s at the frequency α2 during the time interval T2 ′ set to a length approximately equal to the length of the time interval T1 ′.

Next, the sound s detection process by the arrival time detection unit 35A will be described.
Since the filter 32 does not pass the sound wave having the frequency α1 ′, the sound s is not output to the comparator 33 even if the amplitude of the sound pressure in the time interval T1 ′ exceeds the threshold value pth. Therefore, the value of the pulse signal output from the comparator 33 to the microcomputer 34 in the time interval T1 ′ is “0” (the lower diagram in FIG. 9). When the time interval T2 ′ is reached, the filter 32 allows the sound wave having the frequency α2 to pass, so that the comparator 33 outputs “1” to the microcomputer 34 at a constant period.

  In the microcomputer 34, the arrival time detection unit 35 </ b> A detects the arrival of the sound s based on the acquisition of the pulse signal having the value “1”. The arrival time detection unit 35A detects the time t3 ′ at which the signal of the value “1” is first acquired as the arrival time of the sound s. For example, when the arrival time detection unit 35A obtains a signal in which “0” and “1” change at a constant period from a state in which the pulse signal continues “0”, the period is calculated and stored. The arrival time detection unit 35A compares the stored cycle with the cycle in which “0” and “1” obtained from the comparator 33 change. The arrival time detection unit 35A detects X times (for example, 3 times) and “1” continuously, determines that the sound s has arrived, and has determined a predetermined time from the time t4 ′ at which the sound s has been reached The time t3 ′ that is traced back by this time is the arrival time of the sound s. In the example of FIG. 9, the predetermined time is a pulse period r0 ′ × (X−1) + pulse width r1 ′.

  As described above, in the present embodiment, the terminal device 40 continuously outputs the sound s for a certain period, and the amplitude of the amplitude does not pass through the filter 32 in the time interval T1 ′ in which the amplitude of the waveform increases. In the time interval T2 ′ after the change is settled, the sound s is output at the frequency α2 that passes through the filter 32. The position estimation device 30 detects the sound s having the frequency α2, and estimates the arrival time of the sound s at the microphone M1 or the like. Thus, by providing a reference for detecting the completion time of the rise of the waveform, the threshold value for the magnitude of the amplitude simply due to the property of the sound s that the amplitude gradually changes from the start of the output and the amplitude varies. When the sound signal exceeding the threshold is detected, the uncertainty of determination in the case where it is determined that the sound s has arrived can be eliminated.

FIG. 10 is a flowchart showing an example of a sound source position estimation process in the second embodiment of the present invention.
The preconditions are the same as those in the first embodiment (FIG. 5). First, the user operates the terminal device 40 to start outputting a sound s having a frequency α1 ′. As described above, in the time interval T2 ′, the frequency of the sound s is output as α2. The microphones M1 to M4 collect the sound s (step S31). When the microphones M <b> 1 to M <b> 4 collect the sound s, the microphones M <b> 1 to M <b> 4 convert the sound s into an electric signal and output an analog sound signal of the sound s to the amplifier 31. The amplifier 31 amplifies the analog sound signal of the sound s output from the microphones M <b> 1 to M <b> 4 and outputs the amplified signal to the filter 32. The filter 32 extracts a frequency in a predetermined pass band from the amplified four analog sound signals and outputs the extracted frequency to the comparator 33. In the second embodiment, the filter 32 extracts only the analog sound signal of the sound s output in the time interval T <b> 2 ′ and outputs it to the comparator 33.
The comparator 33 converts each of the four analog sound signals for the sound s collected by the microphones M1 to M4 output from the filter 32 into a pulse signal based on a predetermined threshold, and converts the pulse signal into the microcomputer 34. Output to.

  In the microcomputer 34, the arrival time detection unit 35A acquires four pulse signals, and estimates the arrival time of the sound s to each of the microphones M1 to M4 (step S32). Specifically, the arrival time detection unit 35 </ b> A detects the value “1” for each of the four pulse signals as described with reference to FIG. 9. For example, the arrival time detection unit 35 </ b> A determines that the sound s has been detected when “1” is detected continuously in a pulse signal acquired from the comparator 33 or a predetermined number of times or more in total. The arrival time detection unit 35A detects and stores the time at which it is determined that the sound s is detected, the pulse period, the pulse width, and the like. The arrival time detection unit 35A calculates a time that is a predetermined time later than the time at which it is determined that the sound s is detected, using the time at which it is determined that the stored sound s is detected, the pulse period, the pulse width, and the like. The estimated time is estimated as the arrival time of the sound s. The arrival time detection unit 35A outputs the estimated arrival times (four) of the sound s to the microphones M1 to M4 to the position estimation unit 36. The position estimation unit 36 determines, for example, the arrival time difference of the sound s from the microphone M1 and the microphone M2 from the arrival time of the sound s to the microphones M1 to M4, the arrival time difference of the sound s from the microphone M1 to the microphone M3, the microphone The arrival time difference of the sound s to M1 and the microphone M4 is calculated, and the position of the sound source (terminal device 40) is estimated by TDOA (step S33).

According to the present embodiment, the microcomputer 34 can obtain the same effects as those of the first embodiment without performing signal processing in the time interval T1 ′.
In the above description, the terminal device 40A outputs the sound wave having the frequency α1 ′ that does not pass through the filter 32 in the time interval T1 ′. However, the position estimation process of the present embodiment adjusts the passband of the filter 32. In this case, it may be realized by providing a filter that does not pass the frequency of the sound s output in the time interval T1 ′.

FIG. 11 is a diagram illustrating an example of a hardware configuration of the position estimation device and the terminal device in each embodiment of the present invention.
The computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an interface 904, and a sound signal processing circuit 905.
The position estimation devices 30 and 30A and the terminal devices 40 and 40A described above include a computer 900. The operation of each processing unit described above is stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads a program from the auxiliary storage device 903, develops it in the main storage device 902, and executes the above processing according to the program. Further, the CPU 901 secures a storage area in the main storage device 902 according to the program.

  In at least one embodiment, the auxiliary storage device 903 is an example of a tangible medium that is not temporary. Other examples of the tangible medium that is not temporary include a magnetic disk, a magneto-optical disk, an optical disk, and a semiconductor memory connected via the interface 904. When this program is distributed to the computer 900 via a communication line, the computer 900 that has received the distribution may develop the program in the main storage device 902 and execute the above processing.

  Each process in the position estimation devices 30, 30A and the terminal devices 40, 40A described above is stored in a computer-readable recording medium in the form of a program, and this program is stored in the position estimation devices 30, 30A, the terminal device 40. , 40A is read and executed by the computer of 40A. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.
The position estimation devices 30 and 30A and the terminal devices 40 and 40A may be configured by a single computer, or may be configured by a plurality of computers connected so as to be communicable.

  The sound signal processing circuit 905 includes an amplifier that amplifies the sound signal, a band-pass filter that passes only a predetermined frequency band, a comparator, an A / D converter that converts an analog sound signal into a digital sound signal, and an analog sound signal that is a digital sound signal. D / A converter etc. for converting to For example, in the terminal devices 40 and 40A, a speaker is connected to the interface 904, and in the position estimation devices 30 and 30A, microphones M1 to M4 are connected to the interface 904.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention. The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the time interval of the sound s output by the terminal devices 40 and 40A may be set to three or more as long as the time when the amplitude waveform of the sound wave is settable can be detected.

  For example, in the above embodiment, all of the microphones M1 to M4 are used at the same time. However, the position of the sound source on the plane can be estimated with three microphones. When performing only position estimation on the user's plane, for example, position estimation may be performed using only the microphones M1 to M3, and the remaining microphone M4 may be used when one of the microphones fails. Alternatively, any three of the four microphones M1 to M4 may be selected each time, and position estimation may be performed using the selected microphone.

Alternatively, when performing position estimation on a plane, for one position estimation, estimation using microphones M1, M2, and M3, estimation using microphones M1, M3, and M4, and estimation using microphones M1, M2, and M4 The position estimation process may be performed four times using the microphones M2, M3, and M4, and the average of the four estimation results may be determined as the final position of the terminal device 40.
α2 is an example of the first frequency, and α1 and α1 ′ are examples of the second frequency.
The terminal device 40, the microphones M1 to M4, and the position estimation device 30 constitute a positioning system that estimates the position of the terminal device 40.

DESCRIPTION OF SYMBOLS 10 ... Air conditioner 20 ... Control apparatus 30, 30A ... Position estimation apparatus 31 ... Amplifier 32 ... Filter 33 ... Comparator 34 ... Microcomputer 35, 35A ... Arrival time detection Unit 36 ... position estimation unit 37 ... communication unit 40, 40A ... terminal device M1, M2, M3, M4 ... microphone w ... space s ... sound 900 ... computer 901 ..CPU
902 ... Main memory 903 ... Auxiliary memory 904 ... Interface 905 ... Sound signal processing circuit

Claims (15)

A sound wave output unit that outputs a continuous sound wave by changing to a different frequency for each of a plurality of time intervals; and a terminal device,
A plurality of sensors for collecting the sound waves;
A position estimation device;
With
The sound wave output unit outputs a sound wave having a predetermined first frequency in the first time interval, and outputs a sound wave having a predetermined second frequency in the time interval immediately before the first time interval,
The position estimation device includes:
An arrival time detector for detecting the arrival time of the sound wave of the first frequency;
A position estimation unit that estimates an output position of the sound wave based on a time difference between the arrival times detected by the arrival time detection unit for the sound waves collected by each of the plurality of sensors;
A positioning system. The sound wave output unit outputs the sound wave of the first frequency after elapse of time from the start of the sound wave output until the amplitude of the sound pressure of the sound wave settles within a predetermined range.
The positioning system according to claim 1. The time during which the amplitude change is within a predetermined range is 50 msec or more and 200 msec or less.
The positioning system according to claim 2. The difference between the first frequency and the second frequency is 1 KHz or more,
The positioning system according to any one of claims 1 to 3. The position estimation device is
A filter including the first frequency and the second frequency in a passband;
Further comprising
The arrival time detection unit detects the arrival time based on a difference between the first frequency and the second frequency;
The positioning system according to any one of claims 1 to 4. The position estimation device is
A filter that includes the first frequency in the passband and does not include the second frequency in the passband;
Further comprising
The arrival time detection unit sets the time when the sound wave of the first frequency is detected as the arrival time.
The positioning system according to any one of claims 1 to 4. The sound wave output unit outputs a sound wave of a predetermined frequency band between 10 kHz and 20 kHz.
The positioning system according to any one of claims 1 to 6. The position estimation device is
When the estimation of the arrival time of the sound wave or the estimation of the output position of the sound wave fails, a communication unit that outputs an error signal,
The positioning system according to any one of claims 1 to 7, further comprising: A positioning system according to any one of claims 1 to 8, comprising:
Air conditioning is performed on the output position of the sound wave estimated by the position estimation device,
Air conditioning system. A terminal device that outputs sound waves to notify the position of the device;
A sound wave output unit that outputs a continuous sound wave by changing to a different frequency for each of a plurality of time intervals,
A terminal device comprising: For successive sound waves output at different frequencies for a plurality of time intervals, the arrival time of the sound waves of a predetermined first frequency output in the second time interval or later among the plurality of time intervals is detected. An arrival time detection unit;
A position estimation unit that estimates an output position of the sound wave based on a time difference between the arrival times detected by the arrival time detection unit for the sound waves collected by each of a plurality of sensors;
A position estimation apparatus comprising: A plurality of sensors collecting continuous sound waves output at different frequencies for a plurality of continuous time intervals;
Detecting the arrival time of the sound wave of a predetermined first frequency set for the second and subsequent time intervals among the plurality of time intervals;
Estimating the output position of the sound wave based on the time difference of the arrival time detected in the step of detecting the arrival time for the sound wave detected by each of the plurality of sensors;
A position estimation method comprising: A sound wave output method for notifying an output position of a sound wave,
A continuous sound wave is output by changing to a different frequency for each of a plurality of time intervals, and after a lapse of time from the start of the sound wave output until the amplitude of the sound pressure of the sound wave is settled within a predetermined range Output the sound wave at a frequency of
Sound wave output method. Computer
A continuous sound wave is output by changing to a different frequency for each of a plurality of time intervals, and after a lapse of time from the start of the sound wave output until the amplitude of the sound pressure of the sound wave is settled within a predetermined range Means for outputting the sound wave having a frequency of
Program to function as. Computer
For successive sound waves output at different frequencies for a plurality of time intervals, the arrival time of the sound waves of a predetermined first frequency set for the second and subsequent time intervals among the plurality of time intervals is detected. means,
Means for estimating an output position of the sound wave based on a time difference of the arrival time detected by the means for detecting the arrival time for the sound wave detected by each of a plurality of sensors;
Program to function as.

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