Aircraft voice alarm system tester and test method

Abstract

The invention provides an airplane voice alarm system tester and a testing method. The tester comprises a box body, an AC / DC power supply, a signal source, a control device, an indicating system, an electric second meter, a power meter, an active loudspeaker box and an oscilloscope. The corresponding detection method is designed according to the detection requirements of the airplane voice alarm system on the alarm priority, the power consumption, the system input and output characteristics and the like, so that the system maintenance quality can be reflected more accurately. The tester effectively improves the repair quality of the aircraft voice alarm system, shortens the repair period, and thoroughly meets the repair test requirements of the aircraft voice alarm system.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft onboard equipment testing, in particular to an aircraft voice warning system tester and a test method. Background Art

[0002] The aircraft voice warning system is an important airborne device that receives and processes external warning trigger signals and plays corresponding voice warnings to remind pilots to pay attention and take corresponding countermeasures. The onboard voice warning system of a certain type of aircraft receives onboard warning trigger signals, among which engine power failure, main hydraulic descent, landing gear lowering, overtemperature 1, fuel cut off, engine overvibration, engine icing, overtemperature 2, guide deicing, and auxiliary pump operation are positive control signals, which are triggered by positive electricity; engine fire, converter failure, stall, altitude tolerance, lubricating oil failure, fuel pump failure, environmental control overtemperature, battery overtemperature, fuel filter failure, left oil exhausted, right oil exhausted, wing oil exhausted, remaining oil, and altitude are negative control signals, which are triggered by negative lines. The voice warning system compares each signal and sends the higher priority signal to the integrated warning display light box according to the degree of influence and importance on the aircraft flight or mission execution, drives the corresponding signal in the integrated warning display light box to light up, and sends an audio signal in the headset.

[0003] After an aircraft overhaul, the performance of the aircraft voice warning system needs to be tested. Currently, the main method is to generate a trigger signal on board to observe the working status of the aircraft voice warning system. This requires the cooperation of various aircraft systems, and the testing process is cumbersome. In addition, it can only detect the correspondence between the voice warning phrase and the warning signal in the voice warning system. The existing methods cannot detect other performance of the voice warning system, such as warning priority, power consumption, system input and output characteristics, etc. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention proposes an aircraft voice warning system tester and a test method, which can realize the testing of performance indicators such as the correspondence between voice warning phrases and warning signals, the number of warning paths, the alarm priority, the alarm reset, the channel input current, the output voltage, the power consumption, the speech speed, the sentence interval time, etc. of the aircraft voice warning system.

[0005] The technical solution of the present invention is:

[0006] The aircraft voice warning system tester comprises a box, an AC / DC power supply, a signal source, a control device, an indication system, an electric stopwatch, a power meter, an active speaker and an oscilloscope;

[0007] The AC / DC power supply is used to convert external AC power into DC power required for the tester to work;

[0008] The signal source is used to generate a plurality of warning trigger signals;

[0009] The control device is used to select and control the warning trigger signal so that the warning trigger signal is transmitted to the aircraft voice warning system as required;

[0010] The indicating system includes a voltmeter and an ammeter, which are used to collect and display the DC voltage input to the tester and the voltage and current of the signal output from the tester;

[0011] The active audio system and oscilloscope display the signal output by the aircraft voice warning system in the form of audio and waveform respectively;

[0012] The front panel of the box is equipped with a power switch and corresponding indicator lights, a work / signal selection switch, a work voltage knob, a signal voltage knob, a system signal interface, a voice output interface, an input selection switch, each warning trigger signal self-locking switch and each corresponding indicator light, a normal / current test selection switch, a work / calibration selection switch, an ammeter display screen, a voltmeter display screen, and an oscilloscope display screen;

[0013] The power switch is used to control the operation of the AC and DC power supplies; the working / signal selection switch is used to select the voltage adjustment object as the working voltage or the signal voltage, the working voltage knob is used to adjust the working voltage, and the signal voltage knob is used to adjust the signal voltage; the system signal interface is used to connect the aircraft voice warning system, transmit the warning trigger signal to the aircraft voice warning system, and receive the output signal of the aircraft voice warning system; the voice output interface is used to connect the active audio; the input selection switch is used to select one of several warning trigger signals; the self-locking switches of each warning trigger signal are used to control the generation of each warning trigger signal.

[0014] Furthermore, each warning trigger signal self-locking switch and each corresponding indicator light are arranged in sequence according to the priority of the warning trigger signal.

[0015] Furthermore, the warning trigger signal includes a positive control signal and a negative control signal.

[0016] Furthermore, the control device can automatically connect various warning trigger signals in order of priority by setting timing control, or manually connect one or more of the signals.

[0017] The method for testing using the above aircraft voice warning system tester comprises the following steps:

[0018] Step 1: Preparation before testing:

[0019] Step 1.1: Connect the tester to an AC power source that meets the requirements;

[0020] Step 1.2: Set the work / check selection switch on the front panel of the tester to the "work" position;

[0021] Step 1.3: Turn on the power switch on the front panel of the tester, observe that the indicator light on the power switch lights up, and the voltmeter and ammeter start working; press the self-locking switches of each warning trigger signal respectively, and the corresponding signal lights light up; set the work / signal selection switch to the "work V" position, and adjust the working voltage knob, and adjust the working voltage to the rated working voltage of 27.5V by observing the voltmeter display; then set the work / signal selection switch to the "signal V" position, and adjust the signal voltage knob, and adjust the signal voltage to ≥18V by observing the voltmeter display;

[0022] Step 1.4: Observe whether the oscilloscope display is normal;

[0023] Step 1.5: Pop up the self-locking switches of each warning trigger signal, turn off the power switch, connect the voice output interface to the active audio, and connect the input signal interface to the aircraft voice warning system;

[0024] Step 2: Detection process:

[0025] a. Detect the corresponding relationship between voice alarm signal and voice:

[0026] Set the normal / current test selection switch on the front panel of the tester to the "normal" position; set the input selection switch to any position; turn on the power switch; press the self-locking switches of each warning trigger signal in turn, and use the active audio to determine whether the alarm broadcast content corresponds to the warning trigger signal corresponding to the self-locking switch, and whether the alarm broadcast content reaches the set number of repetitions;

[0027] b. Detection voice alarm signal priority control:

[0028] Turn on the power switch, press all the self-locking switches of the warning trigger signals, play the alarm broadcast content in sequence through the active speaker, select a warning trigger signal that has been broadcast to reset, and then press its self-locking switch after it pops up. The active speaker determines whether to interrupt the current broadcast, and gives priority to broadcasting the reset alarm signal, and then continues to broadcast the interrupted alarm signal;

[0029] c. Detect the power consumption of each warning trigger signal:

[0030] Turn on the power switch, press all the self-locking switches of each warning trigger signal, observe the readings of the voltmeter and ammeter when playing each alarm broadcast content, and obtain the power consumption of each warning trigger signal according to power = current × voltage;

[0031] d. Oil-out alarm memory function test:

[0032] After detecting the priority control of the voice alarm signal or detecting the power consumption of each warning trigger signal, the self-locking switches corresponding to "left oil used up", "right oil used up", and "wing oil used up" are popped up, and the three self-locking switches are pressed again to determine whether there is no more voice broadcast prompt; then all the self-locking switches are popped up and the power switch is turned off; then the power switch is turned on again, and the self-locking switches of "wing oil used up", "left oil used up", and "right oil used up" are pressed again to determine whether there is a voice broadcast prompt;

[0033] e. Input characteristics detection:

[0034] Turn on the power switch, set the working / signal selection switch to the "signal V" position, adjust the signal voltage knob, and adjust the signal voltage to 18V by observing the voltmeter display; set the normal / current test selection switch to the "current test" position;

[0035] Place the input selection switch in the position of a certain warning trigger signal, and press the self-locking switch corresponding to the warning trigger signal. At this time, the current meter displays the input current of the channel corresponding to the warning trigger signal. Repeat this process to complete the input current detection of the channels corresponding to all warning trigger signals.

[0036] f. Output characteristic detection:

[0037] Turn on the power switch, set the normal / current test selection switch to the "normal" position, set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. Use an oscilloscope to record the alarm signal waveform during voice broadcast, and use the oscilloscope to measure the audio output signal amplitude and output power;

[0038] g. Main alarm, main interval, sentence interval, speech speed test detection:

[0039] Turn on the power switch, set the normal / current test selection switch to the "normal" position, set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. Use an oscilloscope to record the alarm signal waveform during voice broadcast, and use the waveform measurement to obtain the main alarm tone duration, main interval duration, sentence interval duration and total duration.

[0040] Beneficial Effects

[0041] The aircraft voice warning system tester proposed in the present invention designs a corresponding detection method for the detection requirements of the aircraft voice warning system for warning priority, power consumption, system input and output characteristics, etc., so as to more accurately reflect the system maintenance quality. The tester effectively improves the repair quality of the aircraft voice warning system, shortens the repair cycle, and completely solves the repair test requirements of the aircraft voice warning system.

[0042] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0044] Figure 1 : Principle block diagram of the aircraft voice warning system tester proposed by the present invention;

[0045] Figure 2 : Circuit schematic diagram of the aircraft voice warning system tester proposed by the present invention;

[0046] Figure 3 : Schematic diagram of the aircraft voice warning system tester panel proposed by the present invention;

[0047] Figure 4 : The alarm signal waveform displayed by the oscilloscope;

[0048] Figure 5 : The alarm signal waveform amplitude test diagram displayed by the oscilloscope

[0049] Figure 6 : Main alarm, main interval, sentence interval, and speech speed test chart. DETAILED DESCRIPTION

[0050] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0051] like Figure 1 As shown, the aircraft voice warning system tester in this embodiment includes a box, an AC / DC power supply, a signal source, a control device, an indication system, an active speaker, and an oscilloscope;

[0052] The AC / DC power supply is used to convert the external 220V AC power into the 27V DC power required for the tester to work.

[0053] The signal source is used to generate 24 warning trigger signals, which include positive control signals and negative control signals; the positive control signals include engine power failure, main hydraulic descent, landing gear lowering, overtemperature 1, fuel cut off, engine overvibration, engine icing, overtemperature 2, guide deicing, and auxiliary pump operation; the negative control signals include engine fire, inverter failure, stall, altitude tolerance, lubricating oil failure, fuel pump failure, environmental control overtemperature, battery overtemperature, fuel filter failure, left oil exhausted, right oil exhausted, wing oil exhausted, remaining fuel, and altitude.

[0054] The control device is used to select and control the 24 warning trigger signals so that the warning trigger signals are transmitted to the aircraft voice warning system as required; the 24 warning trigger signals can be automatically connected in priority order by setting the timing control, or one or more of the signals can be manually connected;

[0055] The indicating system includes a voltmeter and an ammeter, which are used to collect and display the DC voltage of the input tester and the voltage and current of the signal of the output tester;

[0056] The active audio system and oscilloscope display the signal output by the aircraft voice warning system in the form of audio and waveform respectively;

[0057] The front panel of the box is equipped with a power switch and corresponding indicator lights, a work / signal selection switch, a work voltage knob, a signal voltage knob, a system signal interface, a voice output interface, an input selection switch, a 24-way warning trigger signal self-locking switch and corresponding indicator lights for each channel, a normal / current test selection switch, a work / calibration selection switch, an ammeter display screen, a voltmeter display screen, and an oscilloscope display screen; the 24-way warning trigger signal self-locking switches and corresponding indicator lights for each channel are arranged in order according to the priority of the 24-way warning trigger signal;

[0058] The power switch is used to control the operation of the AC and DC power supplies; the working / signal selection switch is used to select the voltage adjustment object as the working voltage or the signal voltage, the working voltage knob is used to adjust the working voltage, and the signal voltage knob is used to adjust the signal voltage; the system signal interface is used to connect the aircraft voice warning system, transmit the warning trigger signal to the aircraft voice warning system, and receive the output signal of the aircraft voice warning system; the voice output interface is used to connect the active audio; the input selection switch is used to select one of the 24 warning trigger signals; the 24-way warning trigger signal self-locking switch is used to control the generation of each warning trigger signal.

[0059] The following steps are used to test the aircraft voice warning system using the above tester:

[0060] Step 1: Preparation before testing:

[0061] Step 1.1: Connect a 220V AC power supply that meets the requirements to the rear panel of the tester;

[0062] Step 1.2: Set the work / check selection switch on the front panel of the tester to the "work" position;

[0063] Step 1.3: Turn on the power switch on the front panel of the tester, the indicator light on the power switch will light up, and the voltmeter and ammeter will start working; press the 24-way warning trigger signal self-locking switches respectively, and the corresponding signal lights will light up; set the work / signal selection switch to the "work V" position, and adjust the working voltage knob, and adjust the working voltage to the rated working voltage of 27.5V by observing the voltmeter display; then set the work / signal selection switch to the "signal V" position, and adjust the signal voltage knob, and adjust the signal voltage to ≥18V by observing the voltmeter display;

[0064] Step 1.4: Observe whether the oscilloscope display is normal;

[0065] Step 1.5: Pop up the 24-way warning trigger signal self-locking switch, turn off the power switch, connect the voice output interface to the active audio, and connect the input signal interface to the aircraft voice warning system;

[0066] Step 2: Detection process:

[0067] 1. Detect the correspondence between voice alarm signal and voice:

[0068] Set the normal / current test selection switch on the front panel of the tester to the "normal" position; set the input selection switch to any position; turn on the power switch; press the 24-way warning trigger signal self-locking switches in sequence, and use the active audio to determine whether the alarm broadcast content corresponds to the warning trigger signal corresponding to the self-locking switch, and whether the alarm broadcast content reaches the set number of repetitions.

[0069] 2. Detection of voice alarm signal priority control:

[0070] Turn on the power switch, press all the 24-way warning trigger signal self-locking switches, play the alarm broadcast content in sequence through the active speaker, select a warning trigger signal that has been broadcast to reset it, pop up its self-locking switch and press it again, and use the active speaker to determine whether to interrupt the current broadcast, and give priority to broadcasting the reset alarm signal, and then continue to broadcast the interrupted alarm signal.

[0071] 3. Detect the power consumption of each warning trigger signal:

[0072] Turn on the power switch, press all the self-locking switches of the 24 warning trigger signals, observe the voltage meter and ammeter readings when playing each alarm broadcast content, and obtain the power consumption of each warning trigger signal based on power = current × voltage.

[0073] 4. Oil-out alarm memory function test:

[0074] After detecting the voice alarm signal priority control or detecting the power consumption of each warning trigger signal, pop up the self-locking switches corresponding to "left oil ended", "right oil ended" and "wing oil ended", and then press these three self-locking switches again to determine whether there is no more voice broadcast prompt; then pop up all the self-locking switches and turn off the power switch; then turn on the power switch again, and press the "wing oil ended", "left oil ended" and "right oil ended" self-locking switches again to determine whether there is a voice broadcast prompt.

[0075] 5. Input characteristics detection:

[0076] Turn on the power switch, set the working / signal selection switch to the "signal V" position, adjust the signal voltage knob, and adjust the signal voltage to 18V by observing the voltmeter display; set the normal / current test selection switch to the "current test" position;

[0077] Place the input selection switch in the position of a certain warning trigger signal, and press the self-locking switch corresponding to the warning trigger signal. At this time, the current meter displays the input current of the channel corresponding to the warning trigger signal. Repeat this process to complete the input current detection of the channels corresponding to the 24 warning trigger signals.

[0078] 6. Output characteristics detection:

[0079] Turn on the power switch, set the normal / current test selection switch to the "normal" position, set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. Use an oscilloscope to record the alarm signal waveform during voice broadcast, and use the oscilloscope to measure the audio output signal amplitude and output power. The specific process is as follows:

[0080] Adjust the oscilloscope's channel amplitude "VOLTS / DIV" adjustment knob to adjust the oscilloscope's unit voltage to 10V. At this time, "CH1---10V" is displayed in the lower left corner of the oscilloscope display; adjust the oscilloscope's time base "SEC / DIV" adjustment knob to make the unit time 250ms. At this time, "M---250ms" is displayed at the bottom of the oscilloscope display.

[0081] Press the "CURSORS" key on the oscilloscope, and the "Cursor Mode" selection key will appear on the oscilloscope screen. After turning it on, three options will appear: "Manual, Auto, Off". After selecting the manual mode, three soft keys will appear: "Type", "CurA", and "CurB". Select "Type" as voltage. At this time, "CurA" (or "CurB") is highlighted. Then adjust the adjustment knob on the right side of the screen to adjust the position of cursor A so that it is flush with the highest end of the alarm signal. Then use the soft key on the right side of the screen to select "CurB" (or "CurA"). At this time, "CurB" is highlighted. Adjust cursor B to make it flush with the lowest end of the alarm signal. Figure 5At this time, the voltage displayed on the oscilloscope screen is the output signal amplitude Vp-p value of the channel. The output power is obtained based on the signal amplitude and resistance value.

[0082] 7. Main alarm, main interval, sentence interval, speech speed test:

[0083] Turn on the power switch, set the normal / current test selection switch to the "normal" position, set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. Use an oscilloscope to record the alarm signal waveform during voice broadcast, and use the waveform measurement to obtain the main alarm tone duration, main interval duration, sentence interval duration and total duration. The specific process is as follows:

[0084] Press the "CURSORS" key on the oscilloscope, and the "Cursor Mode" selection key will appear on the oscilloscope screen. After turning it on, three options will appear: "Manual, Auto, Off". After selecting the manual mode, three soft keys will appear: "Type", "CurA", and "CurB". Select "Type" as time. At this time, "CurA" (or "CurB") is highlighted. Then adjust the adjustment knob on the right side of the screen to adjust the position of cursor A to the front end of the signal. Then use the soft keys on the right side of the screen to select "CurB" (or "CurA"). At this time, "CurB" is highlighted. Adjust cursor B to the corresponding position of the alarm signal. See Figure 6 At this time, the time displayed on the oscilloscope screen is the time to be measured.

[0085] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. An aircraft voice warning system tester, characterized in that: It includes a box, an AC and DC power supply, a signal source, a control device, an indication system, an electric stopwatch, a power meter, an active speaker and an oscilloscope; The AC / DC power supply is used to convert external AC power into DC power required for the tester to work; The signal source is used to generate a plurality of warning trigger signals; The control device is used to select and control the warning trigger signal so that the warning trigger signal is transmitted to the aircraft voice warning system as required; The indicating system includes a voltmeter and an ammeter, which are used to collect and display the DC voltage input to the tester and the voltage and current of the signal output from the tester; The active audio system and oscilloscope display the signal output by the aircraft voice warning system in the form of audio and waveform respectively; The front panel of the box is equipped with a power switch and corresponding indicator lights, a work / signal selection switch, a work voltage knob, a signal voltage knob, a system signal interface, a voice output interface, an input selection switch, each warning trigger signal self-locking switch and each corresponding indicator light, a normal / current test selection switch, a work / calibration selection switch, an ammeter display screen, a voltmeter display screen, and an oscilloscope display screen; The power switch is used to control the operation of the AC and DC power supplies; the working / signal selection switch is used to select the voltage adjustment object as the working voltage or the signal voltage, the working voltage knob is used to adjust the working voltage, and the signal voltage knob is used to adjust the signal voltage; the system signal interface is used to connect the aircraft voice warning system, transmit the warning trigger signal to the aircraft voice warning system, and receive the output signal of the aircraft voice warning system; the voice output interface is used to connect the active audio; the input selection switch is used to select one of several warning trigger signals; the self-locking switches of each warning trigger signal are used to control the generation of each warning trigger signal.

2. The aircraft voice warning system tester according to claim 1, characterized in that: The self-locking switches of each warning trigger signal and the corresponding indicator lights are arranged in sequence according to the priority of the warning trigger signal.

3. The aircraft voice warning system tester according to claim 1, characterized in that: The warning trigger signal includes a positive control signal and a negative control signal.

4. The aircraft voice warning system tester according to claim 2, characterized in that: The control device can automatically connect various warning trigger signals in order of priority by setting a timing control, or manually connect one or more of the signals.

5. A method for testing using the aircraft voice warning system tester according to any one of claims 1 to 4, comprising the following steps: Step 1: Preparation before testing: Step 1.1: Connect the tester to an AC power source that meets the requirements; Step 1.2: Set the work / check selection switch on the front panel of the tester to the "work" position; Step 1.3: Turn on the power switch on the front panel of the tester, observe that the indicator light on the power switch lights up, and the voltmeter and ammeter start working; press the self-locking switches of each warning trigger signal respectively, and the corresponding signal lights light up; set the work / signal selection switch to the "work V" position, and adjust the working voltage knob, and adjust the working voltage to the rated working voltage of 27.5V by observing the voltmeter display; then set the work / signal selection switch to the "signal V" position, and adjust the signal voltage knob, and adjust the signal voltage to ≥18V by observing the voltmeter display; Step 1.4: Observe whether the oscilloscope display is normal; Step 1.5: Pop up the self-locking switches of each warning trigger signal, turn off the power switch, connect the voice output interface to the active audio, and connect the input signal interface to the aircraft voice warning system; Step 2: Detection process: a. Detect the corresponding relationship between voice alarm signal and voice: Set the normal / current test selection switch on the front panel of the tester to the "normal" position; set the input selection switch to any position; turn on the power switch; press the self-locking switches of each warning trigger signal in turn, and use the active audio to determine whether the alarm broadcast content corresponds to the warning trigger signal corresponding to the self-locking switch, and whether the alarm broadcast content reaches the set number of repetitions; b. Detection voice alarm signal priority control: Turn on the power switch, press all the self-locking switches of the warning trigger signals, play the alarm broadcast content in sequence through the active speaker, select a warning trigger signal that has been broadcast to reset, and then press its self-locking switch after it pops up. The active speaker determines whether to interrupt the current broadcast, and gives priority to broadcasting the reset alarm signal, and then continues to broadcast the interrupted alarm signal; c. Detect the power consumption of each warning trigger signal: Turn on the power switch, press all the self-locking switches of each warning trigger signal, observe the readings of the voltmeter and ammeter when playing each alarm broadcast content, and obtain the power consumption of each warning trigger signal according to power = current × voltage; d. Oil-out alarm memory function test: After detecting the priority control of the voice alarm signal or detecting the power consumption of each warning trigger signal, pop up the self-locking switches corresponding to "left oil used up", "right oil used up" and "wing oil used up", and then press the three self-locking switches again to determine whether there is no more voice broadcast prompt; then pop up all the self-locking switches and turn off the power switch; then turn on the power switch again, and press the self-locking switches of "wing oil used up", "left oil used up" and "right oil used up" again to determine whether there is a voice broadcast prompt; e. Input characteristics detection: Turn on the power switch, set the working / signal selection switch to the "signal V" position, adjust the signal voltage knob, and adjust the signal voltage to 18V by observing the voltmeter display; set the normal / current test selection switch to the "current test" position; Set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. At this time, the current meter displays the input current of the channel corresponding to the warning trigger signal. Repeat this process to complete the input current detection of all channels corresponding to the warning trigger signals; f. Output characteristic detection: Turn on the power switch, set the normal / current test selection switch to the "normal" position, set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. Use an oscilloscope to record the alarm signal waveform during voice broadcast, and use the oscilloscope to measure the audio output signal amplitude and output power; g. Main alarm, main interval, sentence interval, speech speed test detection: Turn on the power switch, set the normal / current test selection switch to the "normal" position, set the input selection switch to a certain warning trigger signal position, and press the self-locking switch corresponding to the warning trigger signal. Use an oscilloscope to record the alarm signal waveform during voice broadcast, and use the waveform measurement to obtain the main alarm tone duration, main interval duration, sentence interval duration and total duration.

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