Public address system and radio system

Abstract

To provide a public address system in which the accuracy of blowing monitoring is improved more than before.SOLUTION: The public address system 2 monitors blowing. The loudspeaker 25 outputs sound. The current sensor unit 24 detects a current value 300 of the loudspeaker 25. The monitoring unit 200 determines a sound output state based on the current value 300 detected by the current sensor unit 24, and performs blowing monitoring. Specifically, when current value 300 detected by current sensor portion 24 is smaller than current threshold value 310 stored in storage portion 21, monitoring unit 200 can determine that no sound is output.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention particularly relates to a public address system for a radio system and to a radio system. [Background technology]

[0002] BACKGROUND ART Conventionally, outdoor public address systems that issue audio notifications to local residents using loudspeakers have been used as components of radio systems for disaster prevention administration in prefectures, cities, towns, and villages, etc., to disseminate disaster prevention information and the like. A conventional loudspeaker system includes a receiver that receives radio signals transmitted from a master station, an audio amplifier that drives a speaker, and a loudspeaker. To detect a malfunction of the audio amplifier or loudspeaker, the system may also include a function to check the sound status using a microphone or other device (hereinafter referred to as "sound monitoring").

[0003] Patent Document 1 discloses a conventional wireless system for monitoring sound vibrations, in which a vibration sensor is attached to a trumpet speaker (loudspeaker) at an outdoor slave station. In this system, the master station pre-records the vibration pattern (reference pattern) of the trumpet speaker when a chime is sounded to announce the start of a broadcast. During broadcast, the trumpet speaker outputs a chime, and the vibration sensor detects the vibration pattern associated with the output. If the detection result is the same as the pre-recorded reference pattern, the trumpet speaker is determined to be normal. In this way, the system of Patent Document 1 makes it possible to appropriately monitor the sound emitted from the speaker of the outdoor slave station. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-147893 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional sound collection microphones and sound monitoring using the vibration sensor described in Patent Document 1 (hereinafter referred to as "prior art"), erroneous judgments occur due to disturbances such as surrounding noise.

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a public address system with improved accuracy in monitoring sound output compared to conventional systems, thereby solving the above-mentioned problems. [Means for solving the problem]

[0007] The loudspeaker device of the present invention is a loudspeaker device that performs sound monitoring, and is characterized by comprising a loudspeaker that outputs sound, a current sensor unit that detects the current value of the loudspeaker, and a monitoring unit that determines the output state of the sound based on the current value detected by the current sensor unit and performs sound monitoring. The loudspeaker of the present invention is characterized in that it further comprises a sound collection microphone that collects sound, and the monitoring unit determines the output state of the sound based also on information from the sound collection microphone. The loudspeaker device of the present invention further includes a memory unit that stores a current threshold value, and the monitoring unit determines that the sound is not being output when the current value detected by the current sensor unit is less than the current threshold value stored in the memory unit. The loudspeaker device of the present invention is characterized in that the memory unit further stores an audio threshold, and the monitoring unit determines that the audio is not being output even if the audio collected by the audio collecting microphone is below the audio threshold stored in the memory unit. The loudspeaker device of the present invention is characterized in that the memory unit includes a non-volatile memory, and the monitoring unit outputs a test signal and determines the output state of the audio based on a comparison of the test signal with past current values ​​stored in the non-volatile memory. The wireless system of the present invention is a wireless system that includes a master station and multiple loudspeakers and performs sound monitoring, wherein each of the multiple loudspeakers is equipped with a loudspeaker that outputs sound, a current sensor unit that detects the current value of the loudspeaker, and a transmitter / receiver unit that can transmit the current value detected by the current sensor unit, and the master station is equipped with a monitoring unit that determines the output state of the sound based on the current value obtained from one of the multiple loudspeakers and performs sound monitoring. [Effects of the Invention]

[0008] According to the present invention, a loudspeaker that outputs sound and a current sensor that detects the current value of the loudspeaker can be provided, and by determining the sound output state based on the current value and performing sound monitoring, it is possible to provide a loudspeaker device that has higher accuracy in sound monitoring than conventional devices. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a system configuration diagram showing a schematic configuration of a wireless communication system X according to an embodiment of the present invention. [Figure 2] 2 is a block diagram showing a control configuration of the loudspeaker shown in FIG. 1. FIG. [Figure 3] 3 is a block diagram showing a control configuration for monitoring sound generated when there are a plurality of loudspeakers shown in FIG. 2. FIG. [Figure 4] 10 is a flowchart showing a slave station monitoring process according to an embodiment of the present invention. [Figure 5] 5 is a flowchart showing details of the voice notification sound monitoring process shown in FIG. 4. [Figure 6] 4 is a flowchart illustrating a self-diagnosis noise monitoring process according to an embodiment of the present invention. [Figure 7] FIG. 10 is a system configuration diagram of a wireless system according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Embodiment> Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A schematic configuration of a wireless system X according to this embodiment will be described with reference to Fig. 1. The wireless communication system X is an example of a wireless communication system for disaster prevention administration. The wireless system X is made up of a master station 1 and a plurality of outdoor loudspeaker systems 2 (slave stations). The master station 1 further includes an operation console 3. A relay station 4 that relays radio waves from the master station 1 may also be provided.

[0011] The master station 1 and the operation console 3 are a radio transmitter / receiver and an operation console for disaster prevention radio provided in a prefectural, city, town, or village office.

[0012] Specifically, the operation console 3 generates audio data such as disaster prevention information and wide-area information on disasters, etc., by users such as government officials. For this purpose, the operation console 3 is equipped with a display monitor, an operation panel, an audio mixer, a microphone, and control means such as a CPU (Central Processing Unit) that controls these components.

[0013] The console 3 can also receive instructions to monitor the state of the loudspeaker 2 and present the results to the user. This state monitoring includes the sound monitoring according to this embodiment.

[0014] The master station 1 is equipped with an antenna, a radio transceiver, etc., and modulates and demodulates radio waves, transmits and receives radio waves, and transmits audio data via radio waves. In addition, the master station 1 can also transmit control messages including instructions (commands) to the relay station 4 and the loudspeaker device 2.

[0015] The loudspeaker 2 is an outdoor loudspeaker 2 (slave station) that receives audio data from the master station 1 or the relay station 4 and outputs the data through a loudspeaker 25 (FIG. 2).

[0016] The loudspeaker 2 also has a transmission function and can respond to control messages from the console 3. For example, the loudspeaker 2 can respond (answer back) to an instruction by a control message for "monitoring a slave station" that checks the status of the loudspeaker 2.

[0017] The relay station 4 relays radio waves from the master station 1, and transmits common audio data simultaneously to all of the terminal loudspeaker devices 2 in the wireless communication from the master station 1 to the loudspeaker devices 2 in the same way.

[0018] In addition, between the master station 1, the relay station 4, and the loudspeaker 2, it is also possible to send and receive signals such as a busy notification, a notification that another station is being selected, an automatic recall signal, and a call response signal to each station.

[0019] Next, the control configuration of the loudspeaker 2 will be described with reference to FIG. The public address system 2 includes a control unit 20, a storage unit 21, a transmission / reception unit 22, an audio amplifier unit 23, a current sensor unit 24, and an operation unit 27. The public address system 2 is also connected to a loudspeaker 25 and a sound collection microphone 26.

[0020] The control unit 20 is a control and calculation means composed of a CPU, an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), an NPU (Neural Processing Unit), an ASIC (Application Specific Processor), etc. The control unit 20 controls all of the components that make up the loudspeaker 2.

[0021] The storage unit 21 is a storage means configured to include a volatile memory 211 and a nonvolatile memory 212 . The storage unit 21 may be a non-transitory recording medium.

[0022] Of these, the volatile memory 211 is configured with a DRAM (Dynamic Random Access Memory), an SRAM (Static RAM), or the like. In this embodiment, the volatile memory 211 temporarily stores information such as the sound monitoring results.

[0023] The nonvolatile memory 212 is configured by a ROM (Read Only Memory), etc. This ROM includes a flash memory, etc. In this embodiment, the nonvolatile memory 212 stores a control program and various data for the loudspeaker device 2. Of these, the control program includes an operating system (OS), middleware, device drivers, and various application software (hereinafter simply referred to as "applications"). The various data includes setting information. This setting information also includes thresholds, accumulated values, etc., which will be described later.

[0024] The transmitting / receiving unit 22 includes an antenna A and a wireless transmitting / receiving device that modulates and demodulates radio signals and transmits and receives them. In this embodiment, the transmitter / receiver 22 transmits and receives audio data and control messages to and from the master station 1 or the relay station 4. Specifically, the transmitter / receiver 22 receives audio data for broadcasts such as disaster prevention information, and various control messages. The transmitter / receiver 22 also transmits responses generated by the control unit 20 in response to control messages from the console 3.

[0025] The audio amplifier 23 is a circuit that converts the audio data received by the transmitter / receiver 22 into an audio signal, amplifies the power of the audio signal for loudspeaker broadcasting by the loudspeaker 25, and drives the loudspeaker 25. For this reason, the audio amplifier 23 may include a D / A (Digital to Analog) conversion circuit and an amplifier circuit.

[0026] The current sensor unit 24 is a current measurement circuit or the like that detects the current that drives the loudspeaker 25. The current sensor unit 24 may calculate an integrated current value 300 within a predetermined period in accordance with the output of an AC audio signal to the loudspeaker 25.

[0027] The operation unit 27 is a switch, an LED (Light Emitting Diode), a liquid crystal display, an organic EL display, etc. used for maintenance operations of the loudspeaker device 2. The operation unit 27 can be used, for example, to check for failure detection of each part.

[0028] The loudspeaker 25 outputs the audio signal amplified by the audio amplifier 23, for example, broadcasting disaster prevention information. In this embodiment, the loudspeaker 25 may be a waterproof dynamic speaker equipped with a voice coil, a permanent magnet, and a diaphragm.

[0029] The sound collection microphone 26 is a microphone or the like that collects the sound output by the loudspeaker 25 and outputs an audio signal. The sound collection microphone 26 can detect that the loudspeaker 25 is making noise.

[0030] In addition, the device may also include an operational amplifier and an A / D (Analog to Digital) conversion circuit that convert the analog signal from the current sensor unit 24 and the analog audio signal from the sound collection microphone 26 into digital data and send it to the control unit 20, and a power supply unit that includes a secondary battery and supplies power to each unit.

[0031] Here, the functional configuration of the loudspeaker 2 according to this embodiment will be described. The control unit 20 can function as a monitoring unit 200 by executing a control program stored in the storage unit 21 .

[0032] In this embodiment, the monitoring unit 200 determines the sound output state based on the current value 300 detected by the current sensor unit 24, and performs sound monitoring. Specifically, the monitoring unit 200 can determine that no sound is being output when the current value 300 detected by the current sensor unit 24 is less than the current threshold value 310 stored in the non-volatile memory 212 of the memory unit 21.

[0033] In addition, the monitoring unit 200 can also determine the audio output state based on information from the sound collection microphone 26. Specifically, the monitoring unit 200 can also determine that no sound is being output when the sound signal value 301 collected by the sound collecting microphone 26 is less than the sound threshold value 311 stored in the nonvolatile memory 212 of the storage unit 21. The monitoring unit 200 may further perform an FFT (Fast Fourier Transform) or the like on the sound signal using a DSP to detect damage to the diaphragm of the loudspeaker 25, for example.

[0034] Alternatively, the monitoring unit 200 can output a test signal to the audio amplifier unit 23 and determine the audio output state based on a comparison of the test signal with past current values ​​300 and / or audio signal values ​​301 stored in the nonvolatile memory 212. This test signal may have an audio output smaller than that of a normal disaster prevention broadcast or the like. More specifically, the monitoring unit 200 stores the current value 300 and / or the audio signal value 301 for the test signal for a specific period in the nonvolatile memory 212. Then, the monitoring unit 200 compares the current value 300 and / or the audio signal value 301 for the test signal with previously stored values, and if these are less than the current threshold 310 or the audio threshold 311, it can determine that audio is not being output.

[0035] In this embodiment, as described above, the nonvolatile memory 212 stores the current threshold value 310 and the audio threshold value 311 as setting information. Furthermore, this setting information may store a determination setting indicating whether or how to use current and / or audio when performing sound monitoring. This determination setting may be, for example, a setting to determine using only the current sensor unit 24, a setting to determine using only the sound collecting microphone 26, or a setting to determine using both the current sensor unit 24 and the sound collecting microphone 26. Additionally, the nonvolatile memory 212 may store the current value 300 and the audio signal value 301 for a specific period as described above. In this case, the specific period may be several days to several months, and may be set according to the capacity of the nonvolatile memory 212.

[0036] Furthermore, the non-volatile memory 212 may store audio data or the like as data for generating test signals. This audio data may be data of a sine wave, square wave, or other waveform of a specific frequency, or a predetermined audio signal broadcast at a specific time, such as a sunset broadcast or chimes.

[0037] Referring to FIG. 3, in this embodiment, the loudspeaker device 2 may include a plurality of sound amplifiers 23, current sensors 24, and loudspeakers 25. In the example of FIG. 3, a current sensor unit 24 and a loudspeaker 25 are provided in correspondence with each audio amplifier unit 23. The monitoring unit 200 can acquire the current value 300 from each current sensor unit 24. In addition, the monitoring unit 200 also acquires an audio signal from a sound collection microphone 26 that can collect and acquire audio from a plurality of loudspeakers 25.

[0038] [Substation monitoring process by public address system 2] Next, with reference to FIG. 4, a slave station monitoring process using the wireless system X according to the embodiment of the present invention will be described in detail. In this slave station monitoring process, the loudspeaker 2 monitors the sound during normal broadcasting and transmits the results of the sound monitoring to the master station 1 at the instruction of the master station 1. This enables the master station 1 to monitor the operating status of the loudspeaker 2, which is the slave station, and to present the results on the operation console 3. Below, the slave station monitoring process by the loudspeaker 2 will be explained in detail step by step with reference to Fig. 4. These processes are carried out by the control means of the master station 1 and the console 3, and the control unit 20 of the loudspeaker 2, which executes a control program stored in the storage unit 21 using hardware resources.

[0039] First, in step S100, the console 3, the master station 1, and the loudspeaker 2 perform voice notification processing. The operator console 3 detects that the user has issued an instruction to start a voice message, and then starts the voice message, transmitting the input voice as radio waves from the wireless transmitter / receiver. Then, the transmitter / receiver 22 of the loudspeaker 2 receives and demodulates the radio waves, and the audio signal amplified by the audio amplifier 23 is amplified by the loudspeaker 25. That is, audio is emitted from the loudspeaker 25 of the loudspeaker 2. This makes it possible to inform nearby residents of the broadcast content.

[0040] Next, in step S101, the public address system 2 performs a sound monitoring process. The monitoring unit 200 determines whether the broadcast is being broadcast normally (broadcast monitoring) based on data from the current sensor unit 24 and / or the sound collection microphone 26. The monitoring unit 200 stores the determination result in the volatile memory 211. This determination result may also include information about the reason for the failure. The details of this noise monitoring process will be described later.

[0041] Next, in step S102, the operator console 3 and the master station 1 perform slave station monitoring and notification processing. When the user monitors the operating status of the loudspeaker 2 (monitoring the slave stations), the user can issue an instruction to monitor the slave stations on the operation console 3 during or after the voice message has been sent. Upon receiving this instruction from the user, the operation console 3 notifies the master station 1. The master station 1 transmits a control message requesting monitoring of the operating status (slave station monitoring). At this time, the control message may include information for identifying one (individual) of the multiple loudspeaker devices 2. This transmission may also be almost simultaneous with the voice notification. This allows only a specific loudspeaker device 2 to respond to a request for monitoring a slave station.

[0042] When a specific loudspeaker device 2 receives a control message requesting monitoring of a slave station, it reads out the result of the sound monitoring stored in the volatile memory 211 and returns it to the master station 1 using the answerback function of the transmitter / receiver 22. This result of the sound monitoring may also include information on the reason for the failure. When the master station 1 acquires the result of this determination, it transmits it to the operation console 3.

[0043] Here, in step S103, the operator console 3 determines whether the monitoring result is normal or not. The control means of the operator console 3 judges "Yes" when the judgment result of the sound monitoring is normal, whereas the control means of the operator console 3 judges "No" when the judgment result of the sound monitoring is abnormal. If the answer is Yes, the control means advances the process to step S104. If No, the control means advances the process to step S105.

[0044] If the monitoring result is normal, the operator console 3 performs normal presentation processing in step S104. The console 3 can display on a screen such as a monitor display the fact that the individual loudspeaker 2 is normal as a result of the sound monitoring determination transmitted from the loudspeaker 2. This allows the user to confirm that the voice message has sounded normally.

[0045] On the other hand, if the monitoring result is not normal, the operation console 3 performs an abnormality notification process in step S105. The console 3 can display on a screen such as a monitor display that an individual loudspeaker 2 is abnormal. At this time, as will be shown in the sound monitoring process described later, it is also possible to display an estimate of the reason for the failure, i.e., which part of the individual loudspeaker 2 has failed. This completes the slave station monitoring process according to this embodiment.

[0046] Next, with reference to FIG. 5, the details of the sound monitoring process in the voice notification shown in step S101 of FIG. 4 will be described.

[0047] First, in step S111, the monitoring unit 200 performs an initialization process. When the monitoring unit 200 receives a voice notification from the master station 1, it reads out the current threshold 310 and voice threshold 311 of the setting information and the determination setting from the nonvolatile memory 212. Then, the monitoring unit 200 sets a flag indicating whether the result of the sound monitoring is normal or abnormal to "0," thereby initializing the flag.

[0048] Here, in step S112, the monitoring unit 200 determines whether or not a voice notification is being received. If the notification is being received, the monitoring unit 200 determines Yes. If the reception has ended or the notification has not been received, the monitoring unit 200 determines No. The monitoring unit 200 also determines No if there is a reception disturbance, such as a failure to demodulate the received radio wave. If the answer is Yes, the monitoring unit 200 advances the process to step S113. If the answer is No, the monitoring unit 200 advances the process to step S116.

[0049] If a voice notification is being received, the monitoring unit 200 performs a voice output confirmation process in step S113. In the public address system 2, when an audio signal is amplified from the loudspeaker 25, the current sensor unit 24 detects the current driving the loudspeaker 25 and outputs a current value of 300. Meanwhile, the sound collecting microphone 26 picks up the sound when the loudspeaker 25 sounds and outputs an audio signal. The audio signals from the current sensor unit 24 and the audio microphone 26 are sent to the monitoring unit 200 of the control unit 20.

[0050] The monitoring unit 200 determines the audio output state based on the determination settings of the setting information stored in the nonvolatile memory 212 and performs sound monitoring. If the judgment setting is set to judge only by the current sensor unit 24, the monitoring unit 200 judges the audio output state to be "audio is being output" if the current value 300 detected by the current sensor unit 24 is equal to or greater than the current threshold value 310. Here, when the current value 300 is less than the current threshold value 310, the monitoring unit 200 determines that no sound is being output, that is, the sound output state is "no sound is being output." Furthermore, since the monitoring unit 200 considers that the sound amplifier 23 or the voice coil of the loudspeaker 25 may have been disconnected, the monitoring unit 200 stores information on "estimated failure of the sound amplifier 23 or voice coil" in the volatile memory as the reason for the failure.

[0051] On the other hand, when the determination setting is set to make a determination using only the sound collection microphone 26, the monitoring unit 200 calculates an audio output value, which is, for example, a value obtained by adding and averaging the absolute values ​​of the audio signal at specific intervals. Alternatively, the monitoring unit 200 may use a DSP or the like to perform an FFT or the like on the audio signal acquired by the sound collection microphone 26, compare the audio signal obtained by demodulating the received radio waves with the result of a similar FFT or the like, or obtain a correlation of frequency characteristics, and calculate the audio output value. This audio output value is an example of the information (audio) from the sound collection microphone 26.

[0052] If the audio output value is equal to or greater than the audio threshold 311, the monitoring unit 200 determines that the audio output state is "audio is being output." Alternatively, if the audio output value is less than the audio threshold 311, the monitoring unit 200 determines that the audio output state is "audio is not being output" and stores this information in volatile memory. In this case, a malfunction of the audio amplifier, voice coil, diaphragm, etc. is presumed. For this reason, although not described in detail, the reason for the malfunction may be presumed based on the difference in audio output value or may be presumed in combination with other sensing information, and this information may be stored together in volatile memory.

[0053] Alternatively, if the judgment setting is such that both the current sensor unit 24 and the sound collection microphone 26 are set to judgment, the monitoring unit 200 judges that "sound is being output" if the current value 300 is equal to or greater than the current threshold 310 and the sound output value is equal to or greater than the sound threshold 311. Alternatively, if the current value 300 is less than the current threshold 310 but the audio output value is equal to or greater than the audio threshold 311, it may be determined that "audio is not being output." In this case, the monitoring unit 200 stores in the volatile memory, as the reason for the failure, information such as "misjudgment due to disturbances such as ambient noise or failure of the current sensor unit 24 is estimated." Alternatively, the monitoring unit 200 may determine that "no sound is being output" when the current value 300 is equal to or greater than the current threshold 310 but the sound output value is less than the sound threshold 311. In this case, the monitoring unit 200 stores information on "diaphragm failure estimation" in the volatile memory as the reason for the failure. Alternatively, the monitoring unit 200 may determine that "no sound is being output" when the current value 300 is less than the current threshold 310 and the sound output value is less than the sound threshold 311. In this case, the monitoring unit 200 stores information on "estimated failure of the sound amplifier unit 23 or voice coil" in the volatile memory as the reason for the failure.

[0054] Furthermore, if the monitoring unit 200 has not received radio waves in the first place or if there is a reception disturbance, the monitoring unit 200 stores information indicating "presumed failure of the transmitting / receiving unit 22 or radio wave disturbance" in volatile memory. Furthermore, the monitoring unit 200 may store and accumulate the acquired current values ​​300 and audio signal values ​​301 for a specific period in the nonvolatile memory 212. At this time, the oldest current values ​​300 and audio signal values ​​301 may be deleted in FIFO order in order of oldest.

[0055] Next, in step S114, the monitoring unit 200 determines whether or not sound is being output. The monitoring unit 200 determines Yes when the determination of the audio output state is "audio is being output." On the other hand, the monitoring unit 200 determines No when "audio is not being output." If the answer is Yes, the monitoring unit 200 advances the process to step S115. If No, the monitoring unit 200 returns the process to step S112 and continues receiving the voice notification.

[0056] If a sound has been output, the monitoring unit 200 performs a flag normal setting process in step S115. The monitoring unit 200 sets the above-mentioned sound monitoring flag to "1." Thereafter, the monitoring unit 200 returns the process to step S112 and repeats these processes while receiving the voice notification.

[0057] If the voice notification is not being received, that is, if the reception of the voice notification has ended, the monitoring unit 200 performs sound monitoring to determine whether or not a sound is being output in step S116. The monitoring unit 200 determines the answer as Yes if the above-mentioned sound monitoring flag is set to "1." The monitoring unit 200 determines the answer as No if the flag remains at "0." If the answer is Yes, the monitoring unit 200 advances the process to step S117. If the answer is No, the monitoring unit 200 advances the process to step S118.

[0058] If a sound has been output, the monitoring unit 200 performs normal storage processing in step S117. The monitoring unit 200 stores the result of the sound monitoring as "normal" in the volatile memory 211.

[0059] If no sound is being output, the monitoring unit 200 performs an abnormality storage process in step S118. The monitoring unit 200 stores the result of the sound monitoring as "abnormal" in the volatile memory 211. At this time, the monitoring unit 200 may store information on the reason for the failure according to the judgment setting, such as judgment by the current sensor unit 24 alone, or judgment by both the current sensor unit 24 and the sound collection microphone 26. This completes the sound monitoring process.

[0060] [Self-diagnosis sound monitoring process by public address system 2] Next, with reference to FIG. 6, the self-diagnosis sound monitoring process using the public address system 2 according to the embodiment of the present invention will be described in more detail. In this embodiment, sound monitoring can be performed even when a voice message is not being sent. Here, a self-diagnosis sound monitoring process for monitoring sound during self-diagnosis will be described. The self-diagnosis sound monitoring process by the public address system 2 will be described in detail below, step by step, with reference to Fig. 3. These processes are carried out by the control unit 20 executing a control program in the nonvolatile memory 212 using hardware resources.

[0061] First, in step S200, the monitoring unit 200 performs a test signal ringing start process. The monitoring unit 200 starts self-diagnosis in response to a control message for self-diagnosis from the master station 1 via the console 3, or an instruction by an operator operating a switch via the operation unit 27, or the like. The monitoring unit 200 outputs a test signal based on the audio data stored in the nonvolatile memory 212 from the audio amplifier unit 23 to make the loudspeaker 25 sound.

[0062] Next, in step S201, the monitoring unit 200 performs sound monitoring processing. This processing may be performed in the same manner as step S101 in Fig. 4 and steps S111 to S118 in Fig. 5 described above. Here, in the self-diagnosis, the monitoring unit 200 may use only the current sensor unit 24. That is, the monitoring unit 200 may acquire the current value 300 of the current sensor unit 24, and determine that no audio is being output if the current value 300 is less than the current threshold 310. Specifically, it is possible to accurately set the current threshold 310 based on a comparison of the test signal with past current values ​​300 stored in the non-volatile memory 212, and determine the audio output state. This configuration makes it possible to monitor the sound by lowering the volume of the sound emitted from the loudspeaker 25 compared to when it is broadcast, making it difficult for nearby residents to hear the test signal. It also makes it possible to accurately detect when there is a partial failure in the amplification circuit of the audio amplifier 23, or when the impedance has changed due to rust on the terminals, even if the voice coil is not broken.

[0063] Alternatively, the monitoring unit 200 can also use a sound collection microphone to calculate autocorrelation with audio data from a DSP or the like to detect the degree of deterioration of the loudspeaker 25, deterioration of the diaphragm, etc. In this case, too, during self-diagnosis, the volume of sound emitted from the loudspeaker 25 may be reduced compared to when broadcasting, and sound monitoring may be performed.

[0064] Next, in step S202, the monitoring unit 200 determines whether or not sound is being output. If the monitoring unit 200 determines that "sound is being output" in the sound monitoring described above, the monitoring unit 200 determines the result as "Yes." On the other hand, if the monitoring unit 200 determines that "sound is not being output," the monitoring unit 200 determines the result as "No." If the answer is Yes, the monitoring unit 200 advances the process to step S203. If the answer is No, the monitoring unit 200 advances the process to step S204.

[0065] If a sound is being output, the monitoring unit 200 performs normal notification processing in step S203. The monitoring unit 200 stops issuing the test signal and ends the self-diagnosis. The result of this self-diagnosis may be transmitted to the master station 1 or displayed on an LED or the like of the operation unit 27. Alternatively, the monitoring unit 200 may notify the parent station 1 that the sound monitoring result is normal. In this case, similar to step S104 in Fig. 4, the operation console 3 may display on a screen such as a monitor display that the sound monitoring result is normal. This completes the self-diagnosis noise monitoring process.

[0066] On the other hand, if no sound is being output, the monitoring unit 200 performs an abnormality notification process in step S204. After finishing sounding the test signal, the monitoring unit 200 displays an abnormality on the LED or the like of the operation unit 27. The monitoring unit 200 may also notify the parent station 1 that the sound monitoring result is abnormal. In this case, similar to step S105, the operation console 3 can also display on the screen of the monitor display that the sound monitoring result is abnormal and an estimate of the cause of the failure. This completes the self-diagnosis noise monitoring process according to this embodiment.

[0067] The above configuration can provide the following effects. Conventionally, there have been radio systems used by municipalities for disaster prevention administration to disseminate disaster prevention information, etc. The public address systems of these conventional radio systems have included a sound monitoring function that checks the sound status using a sound collecting microphone in order to detect malfunctions in the sound amplifier and loudspeaker. In such conventional sound monitoring, sound detection is performed using a sound collection microphone, and therefore, external disturbances such as surrounding noise can lead to erroneous judgments.

[0068] In contrast, (1) the loudspeaker device 2 according to an embodiment of the present invention is a loudspeaker device that performs sound monitoring, and is characterized by comprising a loudspeaker 25 that outputs sound, a current sensor unit 24 that detects a current value 300 of the loudspeaker 25, and a monitoring unit 200 that determines the sound output state based on the current value 300 detected by the current sensor unit 24 and performs sound monitoring.

[0069] With this configuration, sound monitoring is performed by determining the sound output state based on the current value 300, which reduces erroneous determinations due to disturbances and improves the accuracy of sound monitoring compared to conventional techniques.

[0070] Furthermore, conventionally, when a single loudspeaker system is provided with a plurality of loudspeakers, it may also be provided with the same number of sound amplifiers. In such cases, even if one loudspeaker or one audio amplifier fails, the other loudspeakers will continue to sound during broadcasts, etc. Therefore, the sound collecting microphone will detect the sound of the other undamaged loudspeakers, making it impossible to detect the failure.

[0071] In contrast to this, in the loudspeaker system 2 according to this embodiment, by using the current sensor unit 24, even if a plurality of loudspeakers 25 are provided, it is possible to detect failures in each of the loudspeakers. That is, the current sensor unit 24 can be used as a means for detecting the current that drives each loudspeaker 25 and detecting that each loudspeaker 25 is operating.

[0072] Furthermore, (2) the public address system 2 according to the embodiment of the present invention is characterized in that it is the public address system described in (1) further comprising a sound collection microphone 26 that collects sound, and the monitoring unit 200 determines the sound output state based on information from the sound collection microphone 26 as well.

[0073] With this configuration, it is possible to grasp the state of the sound output from the information of the sound collecting microphone 26 and the current sensor unit 24, and a highly reliable sound monitoring function can be realized.

[0074] Furthermore, (3) the loudspeaker 2 according to the embodiment of the present invention is characterized in that it is a loudspeaker as described in (1) or (2), further comprising a memory unit 21 that stores a current threshold 310, and the monitoring unit 200 determines that no sound is being output when the current value 300 detected by the current sensor unit 24 is less than the current threshold 310 stored in the memory unit 21.

[0075] With this configuration, more accurate noise monitoring based on the current threshold 310 can be performed.

[0076] Furthermore, (4) the public address system 2 according to the embodiment of the present invention is characterized in that it is a public address system described in any one of (1) to (3), further comprising a memory unit 21 that stores an audio threshold 311, and the monitoring unit 200 determines that no audio is being output even when the audio output value of the audio signal collected by the sound collection microphone 26 is less than the audio threshold 311 stored in the memory unit 21.

[0077] By configuring in this way, it is possible to perform more accurate noise monitoring based on the audio threshold value 311.

[0078] Additionally, while there have been models available in the past that perform sound monitoring by sounding specific test signals, these could be heard by nearby residents, raising the possibility of receiving complaints from local residents.

[0079] In contrast, (5) in the loudspeaker device 2 according to an embodiment of the present invention, the storage unit 21 includes a non-volatile memory 212, and the monitoring unit 200 outputs a test signal and determines the audio output state based on a comparison of the test signal with past current values ​​300 stored in the non-volatile memory 212, which is a loudspeaker device described in any of (1) to (4).

[0080] With this configuration, the public address system 2 generates a test signal and compares and verifies the information from the current sensor unit 24 with the test signal, thereby enabling self-diagnosis of a malfunction. This makes it possible to monitor the malfunction status of the audio amplifier unit 23 and the loudspeaker 25 at a volume that cannot be detected by the sound collection microphone 26, i.e., a volume that cannot be heard by nearby local residents. This reduces the possibility of complaints from local residents and enables more frequent malfunction detection, contributing to improved system reliability. Furthermore, by storing the judgment threshold value in the nonvolatile memory 212, it becomes possible to flexibly change the judgment criteria and perform accurate noise monitoring.

[0081] Other Embodiments In the above embodiment, an example has been described in which the loudspeaker 2 itself includes the monitoring unit 200 that monitors sound. However, it may also be provided in the master station 1 or the console 3.

[0082] FIG. 7 shows an example of the system configuration of a wireless system Y in which the master station 1 is provided with a monitoring unit 200 in this manner. As in this example, (6) a wireless system Y according to an embodiment of the present invention is a wireless system that includes a master station 1 and a plurality of loudspeaker devices 2 and performs sound monitoring, wherein each of the plurality of loudspeaker devices 2 includes a loudspeaker 25 that outputs sound, a current sensor unit 24 that detects a current value 300 of the loudspeaker 25, and a transmitter / receiver unit 22 that can transmit the current value 300 detected by the current sensor unit 24, and the master station 1 includes a monitoring unit 200 that determines the sound output state based on the current value 300 acquired from one of the plurality of loudspeaker devices 2 and performs sound monitoring.

[0083] This configuration makes it possible to provide a wireless system that performs fault diagnosis using data acquired from multiple loudspeaker devices 2. That is, in a wireless communication system in which audio generated by an operation console 3 is transmitted from a master station 1 to a terminal loudspeaker device 2 and output from the loudspeaker device 2, it becomes possible to monitor the sound output from each loudspeaker device 2 from the operation console 3 via the master station 1.

[0084] In such a wireless system Y, for example, by comparing the current value 300 and the audio signal value 301 between multiple loudspeaker devices 2, it is possible to more accurately identify a fault. That is, by storing the current value 300 and the audio signal value 301 of each loudspeaker device 2 in the non-volatile storage unit 21, it is possible to diagnose a loudspeaker device 2 that is a statistical outlier as having a fault. It is also possible to accurately set the current threshold value 310 and the audio threshold value 311. Furthermore, it is also possible to determine the aging deterioration of each part of the loudspeaker device 2.

[0085] In addition, by comparing the audio signal values ​​301 acquired by the sound collection microphone 26 of each loudspeaker 2 as described above using a DSP or the like, it is possible to better understand malfunctions of the loudspeaker 25, deterioration of the diaphragm, etc.

[0086] In the above embodiment, the current value 300 is determined by the current threshold 310, and the audio signal value 301 is determined by the audio threshold 311. However, in ... audio threshold 311. However, it is also possible to monitor the current and sound information using other methods. For example, it is possible to use a value obtained by integrating the rate of change of AC as the current value 300 of the current sensor unit 24. Alternatively, it is also possible to apply a DC voltage to the loudspeaker 25 and directly obtain the DC current value 300. Alternatively, the audio information may not be simply a D / A converted audio signal from the sound collection microphone 26, but may be a signal that has been divided into frequency bands or that has undergone echo cancellation.

[0087] In the above embodiment, the example has been described in which the functions of the monitoring unit 200 are realized by the control unit 20 executing a program. However, it is also possible to configure the monitoring unit 200 as a circuit. In this case, the output of the circuit of the monitoring unit 200 may be acquired by the control unit 20, and the result of the sound monitoring may be determined.

[0088] This configuration allows for a variety of configurations to be accommodated in accordance with various applications.

[0089] It goes without saying that the configurations and operations of the above-described embodiments are merely examples, and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0090] 1 Master station 2 Public address system 3 Control console 4. Relay Station 20 Control Unit 21 Memory section 22 Transmitter / Receiver 23 Audio amplifier 24 Current sensor section 25 Public address speakers 26 Sound collection microphone 27 Control section 200 Monitoring Department 211 Volatile Memory 212 Non-volatile memory 300 Current value 301 Audio signal value 310 Current Threshold 311 Audio Threshold X, Y radio system

Claims

1. A public address system for monitoring sounding, a loudspeaker for outputting audio; a current sensor unit for detecting a current value of the loudspeaker; a monitoring unit that determines the output state of the sound based on the current value detected by the current sensor unit and monitors sound output. A loudspeaker system characterized by:

2. Further provided with a sound collection microphone for collecting sound, The monitoring unit The output state of the audio is determined based on the information from the sound collecting microphone.

2. The loudspeaker system according to claim 1.

3. Further comprising a storage unit for storing a current threshold value; The monitoring unit When the current value detected by the current sensor unit is less than the current threshold value stored in the storage unit, it is determined that the sound is not being output.

3. The loudspeaker system according to claim 2.

4. The storage unit further stores an audio threshold value; The monitoring unit If the sound collected by the sound collecting microphone is less than the sound threshold stored in the storage unit, it is also determined that the sound is not being output.

4. The loudspeaker system according to claim 3.

5. the storage unit includes a nonvolatile memory, The monitoring unit A test signal is output, and the audio output state is determined based on a comparison of the test signal with past current values ​​stored in the nonvolatile memory.

5. The loudspeaker system according to claim 1, wherein the loudspeaker is a casing.

6. A wireless system that includes a master station and a plurality of loudspeakers and performs sound monitoring, Each of the plurality of loudspeaker devices comprises: a loudspeaker for outputting audio; a current sensor unit for detecting a current value of the loudspeaker; a transmitter / receiver capable of transmitting the current value detected by the current sensor unit, The master station a monitoring unit that determines the output state of the sound based on the current value acquired from any one of the plurality of loudspeaker devices and monitors sound output; A wireless system characterized by:

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