TW201735015A - Automatically reducing noise system and method for UAV - Google Patents

Abstract

The invention is related to an automatically reducing noise system and method for the UAV (Unmanned Aerial Vehicle). The automatically reducing noise system includes a microphone, a signal processor, a speaker and a look up table of turning, acceleration, deceleration, takeoff, landing of the UAV. The microphone receives the flying noise of the UAV. The signal processor converts the noise into a digital signal, inverts the digital signal phase, then converts it to an analog signal. The speaker outputs the analog signal to offset the flying noise of the UAV within a certain range. Furthermore, this invention can reduce the sonic boom phenomenon of turning, acceleration, deceleration, take off, landing of the UAV.

Description

Unmanned aerial vehicle active noise reduction system and method

The present invention relates to an active noise reduction system and method for an unmanned aerial vehicle, and more particularly to an active noise reduction system and method for offsetting the noise of an unmanned aerial vehicle by generating an inverted sound signal.

At present, the unmanned aerial vehicle (UAV) technology is popular, and its use with aerial photography has gradually formed a trend, and because of various prices, it can be accepted by the general consumers, making unmanned flying vehicles extremely common.

However, when the existing unmanned aerial vehicle is performing the flight, the propeller or the suspension wing provided on the unmanned aerial vehicle often generates a huge sound or noise, and like a general helicopter propeller, an unpleasant noise is generated. Unmanned aerial vehicles also have the same noise during flight, often interfering with the operator and the surrounding people.

The invention relates to an active noise reduction system and method for an unmanned aerial vehicle, which is an active noise reduction method and reduces noise during flight of an unmanned aerial vehicle. The unmanned aerial vehicle active noise reduction system includes: a microphone mounted on the unmanned aerial vehicle, or mounted on the unmanned aerial vehicle body or on a suspended line to receive the unmanned flight The sound emitted by the vehicle during flight and outputting a first sound signal; a signal processor disposed in the unmanned aerial vehicle or mounted on the periphery of the unmanned aerial vehicle body or on a suspended line Electrically coupled to the microphone for inverting the first audio signal to output a second audio signal; a speaker disposed on the unmanned aerial vehicle and electrically coupled to the signal a processor for converting the second sound signal into an acoustic wave, and the sound wave is opposite to the sound emitted by the unmanned aerial vehicle when flying, to offset the flight of the unmanned aerial vehicle a sound, and a turn, acceleration, deceleration, takeoff, landing lookup table, electrically coupled to the signal processor for immediately checking the table when the unmanned aerial vehicle performs turning, accelerating, decelerating, taking off, landing Corresponding to the inverted sound wave, the speaker sends it to offset the popping caused by the turn, acceleration, deceleration, takeoff, and landing.

The signal processor includes: an analog/digital converter, an input end of the signal processor for converting the first audio signal into a digital signal; a Fourier converter electrically coupled to the signal processor An analog/digital converter that performs an inversion conversion of the digital signal; and a digital/analog converter electrically coupled to the Fourier converter to convert the inverted digital signal into an analog signal, and The second sound signal.

The unmanned aerial vehicle active noise reduction system is provided with a central computing unit electrically coupled to the turning, accelerating, decelerating, taking off, and landing lookup tables for immediately performing a table lookup to the turn of the unmanned aerial vehicle. Sound signals generated by acceleration, deceleration, takeoff, and landing.

The turning, accelerating, decelerating, take-off, and landing look-up tables are waveforms or corresponding values, amplitudes, and decibel values individually included in each of the actions of turning, accelerating, decelerating, taking off, and landing.

An active noise reduction method for an unmanned aerial vehicle includes the steps of: receiving an audio signal from a microphone of the unmanned aerial vehicle; forming an analog signal; converting the analog signal into a digital signal; performing Fourier transform; converting the Fourier transform The subsequent digital signal is converted into another analog signal; the Fourier-converted analog signal is transmitted by a speaker of the unmanned aerial vehicle; wherein the Fourier transform is performed to perform the inverse conversion, which is received by the microphone The sound is inverted and sent by the speaker to offset the sound received by the microphone; when the unmanned aerial vehicle performs turning, accelerating, decelerating, taking off, and landing, the lookup table immediately corresponds to the turn The sound of bending, accelerating, decelerating, taking off, and landing.

The analog signal formed by the sound received by the microphone is a first sound signal; the other analog signal after the Fourier transform is a second sound signal; the second sound signal is opposite to the first sound signal. Sound signal.

The analog signal is converted into a digital signal, a Fourier transform, and a signal conversion of the digital signal into an analog signal, which is composed by connecting individual circuit devices.

The conversion of the analog signal into a digital signal, a Fourier transform, and a signal conversion of a digital signal into an analog signal is formed by integrating into an integrated circuit.

The conversion of the analog signal into a digital signal, a Fourier transform, and a digital signal converted into an analog signal is performed by a software program.

The lookup table includes waveforms or corresponding values, amplitudes, and decibel values individually for each action corresponding to turning, accelerating, decelerating, taking off, and landing.

10,12‧‧‧Unmanned aerial vehicle

20‧‧‧ microphone

30‧‧‧Signal Processor

32‧‧‧ Analog/Digital Converter

34‧‧‧Fourier converter

36‧‧‧Digital/Analog Converter

40‧‧‧Speakers

50‧‧‧turn, acceleration, deceleration, takeoff, landing lookup table

60‧‧‧Central Computing Unit

1 is a block diagram of a circuit diagram of an embodiment of the present invention; FIG. 2 is a schematic diagram of a method for a UAV flight carrier according to an embodiment of the present invention; FIG. 3 is a flowchart of a method according to an embodiment of the present invention; Schematic diagram of a drone flight vehicle.

The invention relates to an active noise reduction system and method for an unmanned aerial vehicle, which can reduce noise generated by flying a flight of an unmanned aerial vehicle by providing a circuit device, an integrated circuit, or a software function. The sound of the flight vehicle (the sound emitted by the aircraft itself, the airflow noise, etc.) can be received, and the received sound is reversely processed to generate a reverse signal output, which can offset the sound emitted by the noise source within a certain range. , to achieve the effect of active noise reduction.

1 is a block diagram of a circuit according to an embodiment of the present invention, including: a microphone 20, a signal processor 30, a speaker 40, a turn, acceleration, deceleration, takeoff, landing lookup table 50 and a central computing unit 60; Figure 2 shows the unmanned aerial vehicle 10 schematic diagram of the embodiment. The microphone 20 is disposed on the unmanned aerial vehicle 10, or is disposed on the periphery of the unmanned aerial vehicle 10 or on the suspended line to receive the sound of the unmanned aerial vehicle 10 when flying. And outputting a first sound signal; the signal processor 30 is installed in the unmanned aerial vehicle 10, or is installed around the fuselage of the unmanned aerial vehicle 10, or is dropped on the line, and is electrically The microphone is coupled to the microphone 20 for inverting the first audio signal to output a second audio signal. The speaker 40 is disposed on the unmanned aerial vehicle 10 and electrically coupled to the signal processor 30. Transmitting the second sound signal into a sound wave, and the sound wave is opposite to the sound emitted by the unmanned aerial vehicle 10 when flying, to offset the time when the unmanned aerial vehicle 10 is flying. The sounding; and the turning, accelerating, decelerating, taking off, and landing lookup table 50 are electrically coupled to the signal processor for performing the turning, accelerating, decelerating, taking off, and landing when the unmanned aerial vehicle 10 performs the turning, acceleration, deceleration, takeoff, and landing Check the table immediately Acoustic phase, transmitted from the speaker 40, thereby offsetting the turning, acceleration, deceleration, takeoff, landing pop noise generated.

The signal processor 30 illustrated in FIG. 1 includes an analog/digital converter 32, a Fourier converter 34, and a digital/analog converter 36. The analog/digital converter 32 is an input terminal of the signal processor 30 for converting the first audio signal into a digital signal; the Fourier converter 34 is electrically coupled to the analog/ The digital converter 32 performs inverse conversion of the digital signal, that is, performs inverse signal conversion on the digital signal by using an inverse conversion function in the Fourier function; and the digital/analog converter 36 is electrically coupled In the Fourier converter 34, the digital signal after the inversion is converted into an analog signal, such a ratio signal and is the aforementioned second audio signal. At the same time, the second sound signal and the first sound signal are opposite to each other and can cancel each other to reduce the noise generated when the unmanned aerial vehicle 10 flies.

In Fig. 2, the microphone 20 and the speaker 40 are either mounted on the unmanned aerial vehicle 10 or mounted on the periphery of the unmanned aerial vehicle 10 or on a line that is dropped. The microphone 20 is configured to receive the sound of the unmanned aerial vehicle, and the sound is a first sound signal, The sound includes the sound of the unmanned aerial vehicle 10 itself or the airflow noise of the unmanned aerial vehicle 10 during flight. The signal processor 30 may be connected by a whole circuit device, for example, an analog/digital converter (A/D Converter) is connected to a Fourier Transformer and then connected to a digital/analog conversion. (D/A Converter) connected to the composition; or the operation of the signal processor 30 is integrated into an integrated circuit (IC), or alternatively implemented by a software function, and all three embodiments are devices In the unmanned aerial vehicle 10. The speaker 40 is also disposed on the unmanned aerial vehicle 10 to emit the second sound signal for offsetting the first sound signal.

When the unmanned aerial vehicle 10 performs the turning, accelerating, decelerating, taking off, and landing, a popping phenomenon occurs due to the delayed action of the reverse signal. Therefore, the present invention is provided with a turning, accelerating, decelerating, taking off, and landing lookup table 50, so that the immediate lookup table corresponds to the sound signal or sound wave generated when performing the turning, accelerating, decelerating, taking off, and landing, and can immediately generate the corresponding corresponding Reverse signal to offset the noise generated by turning, accelerating, decelerating, taking off, and landing. This immediate action and operation can be accomplished by providing a central computing unit 60, as shown in FIG. 1; or directly using the processor of the unmanned aerial vehicle 10 itself to directly store the stored The turn, acceleration, deceleration, takeoff, and landing lookup tables 50 are completed. The central computing unit 60 is electrically coupled to the turning, accelerating, decelerating, take-off, and landing look-up table 50 for immediately performing a look-up table corresponding to the turning, acceleration, deceleration, take-off, and landing of the unmanned aerial vehicle 10. The resulting sound signal.

Further explaining the contents of the turning, accelerating, decelerating, taking off, and landing lookup table 50, the lookup table is corresponding to the unmanned flying vehicle, executing the flight control command, performing each action of turning, accelerating, decelerating, taking off, and landing. Among them, the sound signal content including waveform or corresponding value, amplitude and decibel value (dB value) is individually included, including various waveform diagrams and corresponding numerical values, as shown in the following table:

The above-mentioned look-up table is only an example. The symbols shown in the table are exemplary values of a numerical value or a waveform, and are not actually used to express the limitation. The turning, accelerating, decelerating, taking off proposed by the present invention The landing lookup table 50 is not limited by the symbols in the above table in actual implementation.

3 is a flowchart of a method according to an embodiment of the present invention, including the steps of: receiving a sound S10 from a microphone of an unmanned aerial vehicle; forming an analog signal S12; converting the analog signal into a digital signal S14; performing a Fourier transform S16; The Fourier-transformed digital signal is converted into another analog signal S18; the analog signal S19 is output by the unmanned aerial vehicle, that is, the Fourier-converted analog signal is transmitted by the speaker of the unmanned aerial vehicle. Similarly, the Fourier transform is used to perform signal inversion conversion, and the audio signal received by the microphone is inverted, and then sent out by the speaker 40 to offset the sound signal received by the microphone 20; When the unmanned aerial vehicle 10 performs turning, accelerating, decelerating, taking off, and landing, the same is immediately obtained by a look-up table (the look-up table can adopt the aforementioned turning, accelerating, decelerating, take-off, landing look-up table 50) The sound of turning, accelerating, decelerating, taking off, and landing to avoid popping.

The analog signal formed by the sound received by the microphone in step S10 of FIG. 3 is a first sound signal; and another type of analog signal after Fourier transform is described in step S18. The number is a second sound signal; the second sound signal and the first sound signal are inverted sound signals for offsetting each other to reduce noise during flight of the unmanned aerial vehicle. In practical embodiments, the signal conversion functions of steps S14 to S18 can be formed by connecting individual circuit devices, for example, using an analog/digital converter (A/D Converter) connected to a Fourier transformer (Fourier Transformer). And then connected to a digital/analog converter (D/A Converter); or the operation of converting the signals described in steps S14 to S18 into an integrated circuit (IC), or alternatively A software program implementation. And the three embodiments described above are all installed in the unmanned aerial vehicle 10, or the device is completed on the periphery of the fuselage of the unmanned aerial vehicle 10 or on the hanging line. And the lookup table includes waveforms or corresponding values, amplitudes, and decibel values for each action corresponding to turning, accelerating, decelerating, taking off, and landing.

FIG. 4 is a schematic diagram of another embodiment of an unmanned aerial vehicle 12. Since there are many types of unmanned aerial vehicles in the workshop, and there are many different types or different sizes, an embodiment will be described. Similarly, the microphone 20 and the speaker 40 in FIG. 4 are connected to the unmanned aerial vehicle 12 for receiving an audio signal and emitting an audio signal.

The unmanned aerial vehicle active noise reduction system and method of the invention can effectively achieve the following effects:

1. Install the active noise reduction system directly on the "unmanned aerial vehicles 10, 12", which can be realized by a circuit device, integrated circuit and software function.

2. The active noise reduction system on the unmanned aerial vehicle 10, 12 is provided with a microphone 20 for receiving the sound of the flying vehicle (sound emitted by the aircraft itself, airflow noise, etc.) and having a speaker 40 that will receive the sound The reverse signal output can offset the sound emitted by the sound source within a certain range to achieve the effect of active noise reduction.

3. When the unmanned flying vehicles 10, 12 change the operating state, for example: turning, accelerating, slowing down, taking off, landing, in the state of active denoising mechanism of the present invention, it will be produced Blasting sound. Each change in operating state is compared to a pop (waveform, amplitude, decibel (dB) value) form.

4. If there is any change in the operating state, the flight control system of the unmanned aerial vehicle will obtain the signal. This signal is compared with a running state and is also in the form of a popping sound. The reverse sound signal is outputted by the lookup table. The waveform, amplitude and decibel value of the sound signal have been recorded in the memory of the active noise reduction system and can be stored by looking up the table to eliminate the pop.

In summary, the present invention provides an active noise reduction system and method for an unmanned aerial vehicle, which effectively reduces the noise of the unmanned aerial vehicle 10, 12, and prevents the unmanned aerial vehicle from interfering with the operator during flight or disturbing other passes. people. It is obvious that the present invention has the requirements for patent application. However, the description of the present invention is merely illustrative of the preferred embodiments, and the scope of the present invention is not limited thereto, and any local variation, modification, or addition is not deviated from the scope of the present invention. in.

20‧‧‧ microphone

30‧‧‧Signal Processor

32‧‧‧ Analog/Digital Converter

34‧‧‧Fourier converter

36‧‧‧Digital/Analog Converter

40‧‧‧Speakers

50‧‧‧turn, acceleration, deceleration, takeoff, landing lookup table

60‧‧‧Central Computing Unit

Claims (10)

An unmanned aerial vehicle active noise reduction system includes: a microphone mounted on the unmanned aerial vehicle, or installed around the fuselage of the unmanned aerial vehicle, or mounted on a suspended line to receive the The unvoiced vehicle emits a sound during flight and outputs a first sound signal; a signal processor is disposed in the unmanned aerial vehicle or is disposed around the fuselage of the unmanned aerial vehicle or the device The undulating line is electrically coupled to the microphone for inverting the first sound signal to output a second sound signal; a speaker is disposed on the unmanned aerial vehicle and electrically coupled The signal processor is configured to convert the second sound signal into an acoustic wave, and the sound wave is opposite to the sound emitted by the unmanned aerial vehicle during flight to offset the flight of the unmanned aerial vehicle a sound that is emitted; and a turn, acceleration, deceleration, takeoff, and landing lookup table electrically coupled to the signal processor for performing a turn, acceleration, deceleration, takeoff, and descent when the unmanned aerial vehicle When, immediately look-up table corresponds to an inverted acoustic wave transmitted by the loudspeaker to offset the turn, acceleration, deceleration, takeoff, landing pop noise generated. The unmanned aerial vehicle active noise reduction system of claim 1, wherein the signal processor comprises: an analog/digital converter, an input end of the signal processor, for using the first sound The signal is converted into a digital signal; a Fourier converter is electrically coupled to the analog/digital converter to perform an inverse conversion of the digital signal; and a digital/analog converter electrically coupled to the Fourier transform The inverted digital signal is converted into an analog signal and is the second audio signal. The unmanned aerial vehicle active noise reduction system of claim 1, wherein a central computing unit is disposed, electrically coupled to the turning, accelerating, decelerating, taking off, The landing lookup table is used to immediately perform a look-up of the sound signals generated by the turning, acceleration, deceleration, take-off, and landing of the unmanned aerial vehicle. The unmanned aerial vehicle active noise reduction system according to claim 1, wherein the turning, accelerating, decelerating, taking off, and landing lookup tables are in each action corresponding to turning, accelerating, decelerating, taking off, and landing. Individually included waveforms or corresponding values, amplitudes and decibels. An active noise reduction method for an unmanned aerial vehicle includes: receiving a sound signal from a microphone of the unmanned aerial vehicle; forming an analog signal; converting the analog signal into a digital signal; performing Fourier transform; and converting the Fourier transformed digit The signal is converted into another analog signal; the Fourier-converted analog signal is transmitted by a speaker of the unmanned aerial vehicle; wherein the Fourier transform is performed to perform the inverse conversion, and the sound received by the microphone is reversed Phase, sent by the speaker to offset the sound received by the microphone; when the unmanned aerial vehicle performs turning, accelerating, decelerating, taking off, landing, the turntable immediately accelerates the turn, accelerates, decelerates, takes off, The sound of landing. The active noise reduction method of the unmanned aerial vehicle according to Item 5, wherein the analog signal formed by the sound received by the microphone is a first sound signal; and the analog signal after the Fourier transform is a second signal. The sound signal; the second sound signal and the first sound signal are inverted sound signals. The method for active noise reduction of an unmanned aerial vehicle according to claim 5, wherein the analog signal is converted into a digital signal, a Fourier transform, and a digital signal converted into an analog signal is converted by an individual circuit device. composition. The method for actively reducing noise of an unmanned aerial vehicle according to claim 5, wherein the analog signal is converted into a digital signal, a Fourier transform, and a signal conversion of a digital signal into an analog signal is integrated into an integrated circuit. form. The unmanned aerial vehicle active noise reduction method according to claim 5, wherein the conversion of the analog signal into a digital signal, a Fourier transform, and a signal conversion of the digital signal into an analog signal is performed by a software program. The method for actively reducing noise of an unmanned aerial vehicle according to claim 5, wherein the look-up table is a waveform corresponding to each of the actions corresponding to turning, accelerating, decelerating, taking off, and landing, or correspondingly Value, amplitude and decibel value.