Method for simulating radiation noise signal of four-rotor unmanned aerial vehicle in motion state

Abstract

The invention provides a method for simulating a radiation noise signal of a four-rotor unmanned aerial vehicle in a motion state. The method comprises the following steps: setting the motion state and basic parameters of a multi-rotor unmanned aerial vehicle to be simulated; setting signal simulation parameters of the four-rotor unmanned aerial vehicle to be simulated; according to the motion state, the basic parameters and the signal simulation parameters of the quad-rotor unmanned aerial vehicle, a rotation frequency sequence of the hovering state of each rotor propeller and an intensity sequence of each harmonic signal are generated in sequence; correcting the rotation frequency sequence of each rotor propeller according to the maneuvering state and basic parameters of the four-rotor unmanned aerial vehicle; generating a radiation signal waveform of each rotor propeller in a maneuvering state according to the signal simulation parameter, the rotation frequency sequence of each rotor propeller and each harmonic signal intensity sequence; and superposing the radiation signal waveforms of the rotor propellers in the maneuvering state to obtain a radiation noise signal of the four-rotor unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention belongs to the field of unmanned aerial vehicle (UAV) acoustic characteristic simulation and signal processing, and in particular relates to a method for simulating the radiation noise signal of a moving quad-rotor UAV. Background Art

[0002] Multi-rotor drones generate unique acoustic signatures during flight. These noises primarily originate from the rotor's aerodynamic noise, the motor's high-frequency electromagnetic noise, and the aircraft's mechanical vibrations. These noises are crucial for acoustic detection equipment to identify and track drone targets. Due to variations in the number of rotors and environmental interference, the radiated noise characteristics vary. This makes it difficult to obtain a sufficiently diverse and controllable noise signature through direct flight testing of real drones.

[0003] Acoustic simulation technology based on signal modeling is now increasingly being applied to drone target detection. By analyzing the correlation between rotor frequency and harmonic distribution, as well as the broadband characteristics of motor noise, researchers are able to construct parameterized drone noise models. These simulated signals have been used to construct acoustic fingerprint databases, train target classification algorithms, and evaluate detection equipment performance, demonstrating significant value in the fields of smart security and military defense.

[0004] Existing drone noise simulation methods still have significant limitations. For example, existing drone simulation methods fail to adequately simulate the frequency variations among propeller blades, making it difficult to generate realistic signals. Existing methods for synthesizing audio from moving drones treat the frequency curves of each rotor blade as identical, failing to account for inter-rotor frequency variations. Therefore, there is an urgent need to develop drone noise simulation systems that support multi-rotor asynchronous frequency coupling modeling, dynamic harmonic superposition, and high-precision propagation attenuation simulation. Summary of the Invention

[0005] Purpose of the invention: In response to the above problems, the purpose of the present invention is to overcome the shortcomings of existing quadrotor UAV noise simulation technology in terms of comprehensiveness and authenticity, and thus propose a method for simulating the radiation noise signal of a moving quadrotor UAV.

[0006] Technical solution: In order to solve the above technical problems and achieve the above invention objectives, the present invention provides a method for simulating the radiation noise signal of a moving quad-rotor drone, which specifically includes the following steps: Step 1: Set the maneuvering state and basic parameters of the quadrotor drone to be simulated; Step 2: Set the signal simulation parameters of the quadcopter to be simulated; Step 3: Generate the rotation frequency sequence of each rotor propeller in the hovering state and the intensity sequence of each harmonic signal in sequence according to the maneuvering state, basic parameters and signal simulation parameters of the quadrotor drone; Step 4: Modify the rotation frequency sequence of each rotor propeller according to the maneuvering state and basic parameters of the quadrotor drone. If the drone is in a hovering state, skip step 4. Step 5: Generate the radiation signal waveform of the quadrotor propeller in the maneuvering state in sequence according to the signal simulation parameters, the rotation frequency sequence of each rotor propeller, and the sequence of each harmonic signal strength; Step 6: Superimpose the waveforms of the propeller radiation signals generated in the maneuvering state in step 5 to obtain the noise radiation signal of the quadrotor drone.

[0007] Furthermore, the motion state of the quadcopter includes hovering, vertical ascent, vertical descent, pitch motion, horizontal motion and yaw motion, as well as the motion start time. , exercise end time and state transition time ,satisfy .

[0008] Furthermore, the basic parameters of the quadcopter include the average rotation frequency of the rotor propeller in the hovering state , rotor propeller rotation frequency fluctuation value .

[0009] Furthermore, the signal simulation parameters include harmonic order , sampling rate Total duration ,in, .

[0010] Furthermore, the specific method of step 3 is as follows: Generate the propeller at the sampling time The rotation frequency sequence ,in, is an integer and satisfies , the generation method is as follows: make , when there is When the absolute value is less than random variable ϵ;

[0011] in, ; Set the Intensity sequence of subharmonic signals ,in, is a non-negative real number, .

[0012] Furthermore, the specific method in step 4 is as follows: Calculate sampling time Correction frequency :

[0013] According to the set UAV motion state, the rotation frequency is adjusted according to the following rules Make corrections: When the drone is ascending vertically:

[0014] When the drone is descending vertically:

[0015] When the drone is in pitch motion:

[0016] When the drone is moving horizontally:

[0017] When the drone is in yaw motion:

[0018] .

[0019] Furthermore, the specific method of step 5 is as follows: calculate Moment Subharmonic signal , the specific method is as follows:

[0020]

[0021] generate Moment Subharmonic signal , the calculation formula is as follows:

[0022] All harmonic signals are linearly superimposed to generate a single propeller signal as follows:

[0023] in, Indicates the propellers The synthetic signal at the moment, according to the signal Generate the radiation signal waveform of each rotor propeller in a given state in sequence.

[0024] Furthermore, the specific method of step 6 is as follows:

[0025] in, express The composite signal at the moment.

[0026] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: (1) When simulating the radiation noise of a moving quadrotor drone, the ambient noise in a complex environment often changes. The present invention can not only simulate the subtle differences in the rotation frequency between the rotors, but also adjust the ambient noise spectrum level to correspond to the ambient noise, making the complex ambient noise simulated in the radiation noise simulation of the moving quadrotor drone more comprehensive.

[0027] (2) The present invention fully considers the dynamic characteristics of the target. Through parametric modeling and signal superposition technology, the simulated UAV noise basically conforms to the noise signal radiated by the actual target during movement.

[0028] (3) The present invention realizes a method for simulating the noise signal of a quadcopter UAV in motion with high fidelity, providing high-fidelity data for the research and testing of the acoustic characteristics of UAVs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings used in the embodiments.

[0030] Figure 1 This is a flow chart of a method for simulating radiation noise signals of a moving quad-rotor drone according to the present invention.

[0031] Figure 2 It is the frequency curve of the noise simulation signal of the quadrotor drone in the vertical ascending motion state.

[0032] Figure 3 It is the radiation waveform signal of the noise simulation signal of the quadrotor drone in the vertical ascending motion state. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the technical solution of the present invention, the present invention is further described below in conjunction with the accompanying drawings and examples. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0034] like Figure 1 As shown, the present invention proposes a method for simulating the radiation noise signal of a moving quadrotor drone, which includes the following steps: Step 1. Set the maneuvering state and basic parameters of the quadcopter to be simulated. The motion state of the quadcopter includes hovering, vertical ascent, vertical descent, pitch motion, horizontal motion, yaw motion and other motion types, as well as the motion start time. , exercise end time and state transition time ,satisfy The basic parameters of the quadcopter include the average rotation frequency of the rotor propeller in hovering state. , rotor propeller rotation frequency fluctuation value .

[0035] Step 2. Set the signal simulation parameters of the quadcopter to be simulated; wherein the signal simulation parameters include the harmonic order , sampling rate Total duration ,in, ; The setting of the initial value of the parameter is based on the requirements of the radiation noise signal to be simulated and the environmental characteristics. The change of the initial value of the parameter indicates the change of the drone noise to be simulated.

[0036] Step 3. According to the maneuvering state, basic parameters and signal simulation parameters of the quadrotor drone, the rotation frequency sequence of each rotor propeller in the hovering state and the intensity sequence of each harmonic signal are generated in sequence.

[0037] Generate the propeller at the sampling time The rotation frequency sequence ,in, is an integer and satisfies , the generation method is as follows: make , when there is When the absolute value is less than random variable ϵ;

[0038] in, ; Set the Intensity sequence of subharmonic signals ,in, is a non-negative real number, . This example is:

[0039] is the average rotation frequency amplitude, here we take .

[0040]

[0041] Step 4. Modify the rotation frequency sequence of each rotor propeller according to the quadcopter's maneuvering state and basic parameters. If the drone is in a hovering state, skip this step. Otherwise, modify the rotation frequency sequence of each rotor propeller as follows: Calculate sampling time Correction frequency , the formula is

[0042] According to the set UAV motion state, the rotation frequency is adjusted according to the following rules Make corrections, When the drone is ascending vertically, ; When the drone descends vertically, ; When the drone is in pitch motion, ; When the drone is moving horizontally, ; When the drone is in yaw motion,

[0043] ; This embodiment takes vertical ascent as an example.

[0044] Step 5. Generate the radiation signal waveform of the quadrotor propeller in a given state in sequence according to the signal simulation parameters, the rotation frequency sequence of each rotor propeller, and the sequence of each harmonic signal strength. The specific method is as follows: Calculate the Subharmonic signal Phase at each moment , the formula is as follows:

[0045]

[0046] generate Moment Subharmonic signal , the calculation formula is as follows:

[0047] All harmonic signals are linearly superimposed to generate a single propeller signal , summing all propeller signals to obtain :

[0048] Step 6. Superimpose the radiation signal waveforms of each rotor propeller under the given motion state generated in step 5 to obtain the radiation noise signal of the quadrotor drone. The formula is as follows:

[0049] Among them, such as Figure 2 As shown in , it shows the frequency curve of the noise simulation signal of the quadrotor drone in the vertical ascending motion state, as shown in Figure 3 As shown in the figure, it shows the radiation waveform signal of the noise simulation signal of the quadrotor drone in the vertical ascending motion state.

[0050] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A method for simulating the noise signal radiated by a quad-rotor drone in motion, characterized in that: The method specifically includes: Step 1: Set the maneuvering state and basic parameters of the quadrotor drone to be simulated; Step 2: Set the signal simulation parameters of the quadcopter to be simulated; Step 3: Generate the rotation frequency sequence of each rotor propeller in the hovering state and the intensity sequence of each harmonic signal in sequence according to the maneuvering state, basic parameters and signal simulation parameters of the quadrotor drone; Step 4: Modify the rotation frequency sequence of each rotor propeller according to the maneuvering state and basic parameters of the quadrotor drone. If the drone is in a hovering state, skip step 4. Step 5: Generate the radiation signal waveform of the quadrotor propeller in the maneuvering state in sequence according to the signal simulation parameters, the rotation frequency sequence of each rotor propeller, and the sequence of each harmonic signal strength; Step 6: Superimpose the radiation signal waveforms of each rotor propeller in the maneuvering state generated in step 5 to obtain the radiation noise signal of the quadrotor drone.

2. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 1, characterized in that: In step 1, the motion state of the quadcopter includes hovering, vertical ascent, vertical descent, pitch motion, horizontal motion and yaw motion, as well as the motion start time. , exercise end time and state transition time ,satisfy .

3. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 2, characterized in that: In step 1, the basic parameters of the quadcopter include the average rotation frequency of the rotor propeller in the hovering state , rotor propeller rotation frequency fluctuation value .

4. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 3, characterized in that: In step 2, the signal simulation parameters include harmonic order , sampling rate Total duration ,in, .

5. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 4, characterized in that: The specific method of step 3 is as follows: Generate the propeller at the sampling time The rotation frequency sequence ,in, is an integer and satisfies , the generation method is as follows: make , when there is When the absolute value is less than random variable ϵ; in, ; Set the Intensity sequence of subharmonic signals ,in, is a non-negative real number, .

6. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 5, characterized in that: The specific method in step 4 is as follows: Calculate sampling time Correction frequency : According to the set UAV motion state, the rotation frequency is adjusted according to the following rules Make corrections: When the drone is ascending vertically: When the drone is descending vertically: When the drone is in pitch motion: When the drone is moving horizontally: When the drone is in yaw motion: 。 7. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 6, characterized in that: The specific method of step 5 is as follows: calculate Moment Subharmonic signal , the specific method is as follows: generate Moment Subharmonic signal , the calculation formula is as follows: All harmonic signals are linearly superimposed to generate a single propeller signal as follows: in, Indicates the propellers The synthetic signal at the moment, according to the signal Generate the radiation signal waveform of each rotor propeller in a given state in sequence.

8. The method for simulating the noise signal radiated by a quad-rotor drone in motion according to claim 7, characterized in that: The specific method of step 6 is as follows: in, express The composite signal at the moment.

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