Disclosure of Invention
The invention relates to a built-in conversation system based on microphone array noise reduction, which further improves the problems of large noise, large distortion and large delay commonly existing in the existing built-in conversation system, inhibits the noise, reduces the voice delay and improves the conversation performance;
in order to solve the technical problems, the invention provides the following technical scheme:
the invention provides a built-in conversation system based on microphone array noise reduction,
comprises an earphone microphone group and a telephone set control box;
the earphone microphone set comprises a headset, two groups of microphones are arranged on the headset, one group of microphones are used by a user during conversation and used for collecting human voice, and the other group of microphones have a background noise collection function and are convenient to collect ambient noise;
the machine communication control box carries out differential amplification on two paths of audio signals collected by the two groups of microphones, extracts human voice, and suppresses noise through a voice noise reduction and enhancement algorithm.
Optionally, the headset microphone set further comprises a left sound generating unit, a right sound generating unit, an ear pad, a microphone and a plug wire, wherein the headset is used for fixing the left sound generating unit and the right sound generating unit, and the left sound generating unit and the right sound generating unit are arranged on two sides of a head and are convenient to wear;
the left sounding unit comprises a left shell and a noise reduction module, and is used for voice noise reduction and left ear sounding;
the right sounding unit comprises a right shell, a noise reduction unit and a double-film microphone, and is used for voice noise reduction, right ear sounding and environmental noise reference signal acquisition;
the microphone is used for collecting human voice signals;
the plug lead is used for signal connection of an external interface;
the ear pad is a part of which the head is contacted with the left sound production unit and the right sound production unit, and is used for reflecting the low frequency back to ensure the reproduction of the low frequency.
Optionally, the left sound generating unit further includes a receiver, a fixed cabin, a damping film, and a damping felt, the noise reducing module includes a noise reducing microphone and a noise reducing circuit board, two sets of receivers are disposed in the left casing, and the two sets of receivers can directly convert the audio electrical signal into low-frequency sound waves audible to human ears;
the noise reduction microphone can collect environmental noise in the fixed cabin and convert the environmental noise into an electric signal to be sent to the noise reduction circuit board for processing, after the noise reduction circuit completes processing, the noise reduction circuit generates the electric signal with the phase opposite to that of noise and the same amplitude, sound waves are emitted through the receiver to offset the noise, and the damping film and the damping felt are fixedly installed on the fixed cabin and used for absorbing the noise in the fixed cabin.
Optionally, the right sounding unit is similar to the left sounding unit in structure composition and design principle, the dual-film microphone is configured to receive external environment noise and output the external environment noise to the set-top box, and the set-top box can implement an active noise reduction function through internal operation processing according to received noise reference signals of a main microphone signal and an auxiliary microphone of the dual-film microphone.
Optionally, an earmuff is arranged on the headset and designed to be an ear pressing earmuff, sponge is filled in the earmuff, flannelette covers the earmuff, the sponge has absorption effect on medium-frequency and high-frequency signals, the ear and the diaphragm form a distance, a cavity is formed between the headset and the head, a better space sense is formed, and the comfort level of human ears is improved.
Optionally, the machine-pass control box includes a main control unit, a filtering adapter plate, a light guide panel, a housing, a connector, and a filter, where the connector and the filter are installed on the housing;
the power supply of the machine-pass control box enters the filter through the connector, the filter is connected to the main control unit after filtering, and the isolation power supply module on the main control unit board supplies power to equipment after DC/DC conversion;
the machine-on control box provides a backlight power supply signal for the light guide panel, and the backlight power supply signal passes through the filtering adapter plate and then is connected to the light guide panel to improve the electromagnetic compatibility;
the RS485 signal and the analog audio signal of the machine-connected control box are connected to the main control unit through the connector of the machine-connected control box, and the main control unit performs further processing to realize the functions of equipment;
the core of the main control unit is a processor and an FPGA (field programmable gate array), the processor has good audio processing capacity, and the FPGA is used for realizing the functions of protocol analysis, interface adaptation and logic control.
The invention has the beneficial effects that
The invention arranges a plurality of microphones on the onboard earphone, when the voice and the surrounding environment information are gathered by the plurality of microphones, the microphone array can effectively form a wave beam in the expected direction to pick up the signals in the wave beam, and the noise outside the wave beam is filtered by the microphone array algorithm in the set-top box to the sound collected by the microphone array, thereby achieving the purpose of simultaneously extracting the sound source and inhibiting the noise, and realizing clear conversation in the set-top box.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Examples
As shown in fig. 1-2, the present invention provides an intercom system based on microphone array noise reduction,
comprises an earphone microphone group 1 and a telephone set control box 8;
the earphone microphone set 1 comprises a headset 2, two groups of microphones are arranged on the headset 2, one group of microphones are used by a user during conversation and used for collecting voice, the other group of microphones have a background noise collection function and are convenient for collecting ambient noise, the two groups of microphones adopt a double-membrane moving-coil microphone, the sensitivity is high, a frequency response curve is smooth and flat, noise can be suppressed, and the tone quality is good;
the phone communication control box 8 performs differential amplification on two paths of audio signals collected by the two groups of microphones, extracts human voice, and suppresses noise through a voice noise reduction and enhancement algorithm, and compared with a single microphone enhancement algorithm, the phone communication control box is simple, has smaller voice delay, and further improves the communication performance of a phone communication system;
the headset microphone set 1 further comprises a left sound generating unit 3, a right sound generating unit 4, an ear pad 5, a microphone 6 and a plug wire 7, wherein the headset 2 is used for fixing the left sound generating unit 3 and the right sound generating unit 4, and the left sound generating unit 3 and the right sound generating unit 4 are arranged on two sides of the head and are convenient to wear;
the left sound generating unit 3 comprises a left casing and a noise reducing module, the left sound generating unit 3 is used for voice noise reduction and left ear sound generating functions, the left sound generating unit 3 further comprises a receiver, a fixed cabin, a damping film and a damping felt, the noise reducing module comprises a noise reducing microphone and a noise reducing circuit board, two sets of receivers are arranged in the left casing, two sets of receivers can directly convert audio electric signals into low-frequency sound waves which can be heard by ears of a user, the noise reducing microphone can collect environmental noise in the fixed cabin and convert the environmental noise into electric signals which are sent to the noise reducing circuit board for processing, after the processing of the noise reducing circuit is completed, electric signals which are opposite to noise phases and have the same amplitude are generated, the sound waves are sent by the receivers to offset the noise, and the damping film and the damping felt are fixedly installed on the fixed cabin and used for absorbing the noise in the fixed cabin;
the right sounding unit 4 comprises a right shell, a noise reduction unit and a double-film microphone, the right sounding unit 4 is used for voice noise reduction, right ear sounding and environmental noise reference signal acquisition, the right sounding unit 4 is structurally composed and designed according to a principle similar to that of the left sounding unit 3, the double-film microphone is used for receiving external environmental noise and outputting the external environmental noise to the set-top box 8, and the set-top box 8 can realize an active noise reduction function through internal operation processing according to received main microphone signals and auxiliary microphone noise reference signals of the double-film microphone;
the microphone 6 is used for collecting human voice signals;
the plug lead 7 is used for signal connection of an external interface;
the ear pad 5 is a part of which the head is contacted with the left sound generating unit 3 and the right sound generating unit 4, and the ear pad 5 is used for reflecting low frequency back to ensure the reproduction of the low frequency;
the machine-to-machine control box 8 comprises a main control unit 9, a filtering adapter plate 10, a light guide panel 11, a shell 12, a connector and a filter 13, wherein the connector and the filter 13 are arranged on the shell 12;
the power supply of the machine-pass control box 8 enters the filter 13 through the connector, the filtered power supply is connected to the main control unit 9, and an isolation power supply module on the board of the main control unit 9 supplies power to equipment after DC/DC conversion;
the machine-on control box 8 provides a backlight power supply signal for the light guide panel 11, and the backlight power supply signal passes through the filtering adapter plate 10 and then is connected to the light guide panel 11 to improve the electromagnetic compatibility;
the RS485 signal and the analog audio signal of the set-top box 8 are connected to the main control unit 9 through the connector of the set-top box 8, and the main control unit 9 performs further processing to realize the functions of the equipment;
the core of the main control unit 9 is a processor and an FPGA, the processor has good audio processing capability, the FPGA is used for realizing protocol analysis, interface adaptation and logic control functions, a power module of the set-top box 8 adopts a Huapu HDS10S2805P-M isolation power module, voltage conversion from DC28V to DC5V is realized, the maximum power is 10W, the set-top box has good anti-surge, impact and drop capabilities, and has protection functions of overheat protection, input reverse connection protection, input short circuit protection, output overvoltage protection, output short circuit protection and the like, and the set-top box is strong in reliability and stable in performance; the filter 13 adopts a miniaturized filter 13 product of thirty-three institute of electrical science and technology, provides good performance of the circuit filter 13, the CPU adopts an ARM processor product of the Quanzhi science and technology Limited company, an audio codec is integrated in a unit and supports the expansion of an external audio circuit, has good audio processing performance, and can realize the processing of multi-channel concurrent voice; the CPU in the universal control box 8 completes the adaptation of the SLIP protocol, and realizes the RS485 bus communication with other built-in equipment through the FPGA. The FPGA adopts a domestic low-power-consumption FPGA, and has relatively rich logic resources and a large number of I/O interfaces; the FPGA is combined with a peripheral circuit thereof to mainly finish the acquisition of a knob signal of a light guide panel 11 of the equipment, the signal processing of an RS485 interface, the signaling and voice interaction with a CPU through an SPI interface and an I2S interface, and the processing of the collection, the sound mixing and the like of recorded audio;
the set-top box 8 adopts an A-type audio amplifier in the aspect of audio performance, has good dynamic range and distortion control, adjusts the volume by controlling the gain of the amplifier, and then sends the volume to the earphone microphone set 1 to realize the monitoring of underwater sound;
the machine communication control box 8 adopts an RS485 interface connected with an FPGA for external communication, the highest speed can support data transmission of 10Mbps, the main control unit 9 adopts an ARM processor product of the national Quanzhi science and technology Limited company, an audio codec is integrated in the unit and supports the expansion of an external audio circuit, and the machine communication control box has good audio processing performance and can realize the processing of multi-channel concurrent voice;
the shell 12 of the power-on control box 8 is cuboid, the outer shell is formed by processing aluminum alloy sections (5A 06-F), and the whole outer shell is divided into three parts, namely the shell 12, an upper cover plate 14 and a lower cover plate 15; the thinnest wall of the shell 12 is 1.5mm, in order to control the weight of a product as much as possible and selectively reduce the thickness of the corresponding wall on the premise of ensuring the strength and feasible process, 4 phi 6.7mm through holes are reserved on two sides of the shell 12 and used for installing the product on an airplane, and an aluminum shell can well play a role in shielding, so that the influence of external electromagnetism on an internal circuit and the influence of the product on an external instrument are avoided;
the following are the technical performance data enhanced by the embodiment of the invention:
technical performance of earphone microphone set:
microphone part
a) Frequency response range: 200 Hz-4000 Hz
b) Impedance: 75X (1. + -. 15%) omega (1 KHz)
c) Sensitivity: 68 + -3 dB/Pa (1 KHz) (200 Hz-4 KHz)
d) Distortion: less than or equal to 5% (1 KHz)
e) Signal-to-noise ratio: not less than 12dB
Receiver part
a) Frequency response range: 10 Hz-20 kHz
b) Impedance: (300 + 300) × (1 + -15%) omega ((1 KHz))
c) Sensitivity: not less than 95dB/mW (1 KHz) (10 Hz-20 kHz)
d) Sound insulation amount: not less than 32dB (315 Hz-8 KHz)
e) The limit does not damage the power: not less than 200mW (200 mW)
f) Distortion: less than or equal to 5 percent (100mW, 1KHz) (5 percent)
(II) the technical performance of the mechanical communication control box is as follows:
a) Audio response: 2dB, frequency response range: 300 Hz-3400 Hz;
b) Harmonic distortion:
1) Conversation and receiving states: not more than 4% (1 kHz);
2) The state of speaking: not more than 2% (1 kHz);
c) Channel audio isolation: greater than 50dB (1 kHz);
d) Signal-to-noise ratio: greater than 50dB (1 kHz);
e) Load characteristics: the output change of 600-300 omega load (during communication) is less than or equal to 3dB;
f) Line input/output level:
1) Inputting conversation and speaking: 1.5mV/75 Ω;
2) And (3) call output: 7.75+2-1V/600 omega;
3) And audio recording output: (2.0 +/-10%) V/10K omega;
therefore, the invention has the noise reduction function of the microphone array.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.