A method for controlling active sound waves

Abstract

The present invention discloses a method for controlling the emission of active sound waves, comprising: S1, parsing CAN signals or receiving vehicle control signals to synthesize active sound wave audio signals; S2, arranging multiple speakers in the vehicle, establishing a plane polar coordinate system in the vehicle, and calculating the polar coordinates of the sound waves in the plane polar coordinate system based on the vehicle's navigation direction and intersection distance information; S3, determining the sound wave audio signals ultimately output by each speaker channel. This method for controlling the emission of active sound waves uses a sound intensity localization method to enable the active sound waves to be played at a localized position in the vehicle. Since the position of the active sound waves in the vehicle changes with the distance from the intersection, the driver can hear the navigation direction and distance information. This assists the driver in making real-time judgments on the navigation direction and distance without reducing the volume of the active sound waves, thereby increasing driving pleasure and improving driving safety while maintaining a stable active sound volume.

Description

Technical Field

[0001] The present invention relates to the field of active acoustic technology, and in particular to a method for controlling the generation of active sound waves. Background Art

[0002] Active sound technology is widely used in new energy vehicles. The program decodes CAN signals or receives vehicle control signals to obtain vehicle operating status information. It then uses an engine sound simulation algorithm to simulate the exhaust system sounds of different engine types. Alternatively, it uses a sound fitting algorithm to modify and play pre-saved audio files (such as time-travel sounds) to match the vehicle's operating status. Active sound technology can enhance driving pleasure and add a sense of sportiness and technology.

[0003] However, active acoustic sound often interferes with vehicle navigation sound. If the active acoustic sound and vehicle navigation sound are played simultaneously, muffling the active acoustic sound will disrupt the sense of continuity, causing the sound to fluctuate and affect the auditory experience. If the navigation sound and active acoustic sound are played together, it can interfere with the driver's understanding of the navigation information and affect driving safety. Summary of the Invention

[0004] The purpose of the present invention is to address the problems in the prior art and provide a method for controlling the sound generation of active sound waves, so that the synthesized sound waves can not only enhance the vehicle's sense of movement and improve driving pleasure, but also provide navigation information in real time through hearing, assisting the driver in judging the navigation direction and distance, and improving driving safety.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for controlling the generation of active sound waves comprises the following steps:

[0007] S1, analyzes CAN signals or receives vehicle control signals through the active sound generation program to synthesize active sound audio signals;

[0008] S2: Multiple speakers are arranged inside the vehicle. A plane polar coordinate system is established inside the vehicle with the center point of the vehicle as the coordinate origin. The polar coordinates p(r,θ) of the sound wave in the plane polar coordinate system are calculated based on the vehicle navigation direction and the distance information of the intersection.

[0009] S3, determining the sound wave audio signal finally output by each of the speaker channels.

[0010] Preferably, in step S2, the minimum distance between each loudspeaker and the center point of the vehicle is set to a unit length of 1 in the polar coordinate system.

[0011] Preferably, the calculation formula for the polar diameter r of the sound wave in the plane polar coordinate system is: r = 1-e -d , where e is the natural logarithm and d is the distance between the navigation intersection and the vehicle.

[0012] Preferably, the polar angle θ of the sound wave in the plane polar coordinate system is the navigation direction, which is given by the navigation software. Turning right, going straight, turning left, and turning around are mapped to 0°, 90°, 180°, and 270° respectively, and the remaining navigation directions are generated by angle interpolation.

[0013] Preferably, step S3 includes the following steps:

[0014] (1) Calculate the Euclidean distance d between the sound wave spatial position p(r,θ) and each of the loudspeakers pm ;

[0015] (2) Calculate the audio gain coefficient g of each speaker channel pm ;

[0016] (3) The audio gain coefficient g of each speaker channel is pm Perform equalization processing;

[0017] (4) Multiplying the audio gain coefficient of each speaker channel after equalization processing by the active sound audio signal obtained in step S1 to obtain the sound audio signal finally output by each speaker channel.

[0018] Preferably, d pm The calculation formula is: Among them, m is the speaker number, s m (r m ,θ m ) is the polar coordinate of the m-th loudspeaker.

[0019] Preferably, g pm The calculation formula is: g pm =1 / d pm .

[0020] Preferably, the audio gain coefficient g of each speaker channel after equalization is pm-nom The calculation formula is: Where z is the total number of speakers.

[0021] Preferably, step S1 includes the following steps:

[0022] (1) Set the motor speed r m and the speed r of the internal combustion engine or e , order n, and obtain multiple sound frequency values ​​f of the sound wave to be synthesized n , f n =r m×r e-max / r m-max ×n, where r e-max is the maximum speed of the internal combustion engine or engine, r m-max is the maximum speed of the motor, n is a positive integer less than 5;

[0023] (2) Compare the accelerator pedal or throttle opening p with the preset maximum sound pressure amplitude a of each order. n-max Match and get the amplitude information a of each frequency sound fn , a fn =p×r m / r m-max ×a n-max ;

[0024] (3) Adjust the overall acceleration amplitude gain a of the sound wave g , when the vehicle's current acceleration g c >0, a g =g c / g max , g max is the maximum acceleration of the vehicle; when the vehicle's current acceleration g c When ≤0, a g =0;

[0025] (4) Perform inverse Fourier transform on each frequency sound and accumulate it to obtain the active sound wave audio signal y out ,y out =a g ×∑(ifft(a fn ×f n )).

[0026] Preferably, there are four speakers, which are respectively arranged on the left and right sides of the front part and the left and right sides of the rear part of the vehicle.

[0027] Due to the application of the above-mentioned technical solution, the present invention has the following advantages over the prior art: The present invention's active sound control method utilizes the spatial positioning capabilities of the vehicle's multi-channel speakers to map the navigation direction and intersection distance into in-vehicle spatial coordinates. Using sound intensity localization, the active sound is played at the desired location within the vehicle. Because the in-vehicle location of the active sound changes with the distance from the intersection, the driver can hear the navigation direction and distance information, assisting the driver in making real-time judgments about the navigation direction and distance without reducing the volume of the active sound. This increases driving pleasure while improving driving safety while maintaining a stable active sound volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Attachment Figure 1 This is an algorithm flow chart of the active sound wave sound control method of the present invention;

[0029] Attachment Figure 2 Schematic diagram of the layout of in-vehicle speakers in the active sound control method of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0031] The algorithm flow chart of the active sound wave sound control method of the present invention is as follows Figure 1 As shown, the specific steps include the following.

[0032] S1, synthesizes active sound audio signal.

[0033] The active sound generation program analyzes the CAN signal or receives the vehicle control signal to synthesize the active sound audio signal.

[0034] Specifically include:

[0035] (1) The current motor speed r m and the speed r of the internal combustion engine or e , order n, and obtain multiple sound frequency values ​​f of the sound wave to be synthesized n , see formula (1) for details.

[0036] f n =r m ×r e-max / r m-max ×n (1)

[0037] Among them, r e-max is the maximum speed of the internal combustion engine or engine, r m-max is the maximum speed of the motor, and n is a positive integer less than 5.

[0038] (2) Compare the accelerator pedal or throttle opening p with the preset maximum sound pressure amplitude a of each order. n-max Match and get the amplitude information a of each frequency sound fn , see formula (2) for details.

[0039] a fn =p×r m / r m-max ×a n-max (2)

[0040] The accelerator pedal or throttle opening p is between 0 and 1.

[0041] (3) According to the acceleration state of the vehicle, adjust the overall acceleration amplitude gain a of the sound wave g, see formula (3) for details. This ensures that the synthesized sound wave amplitude is consistent with the driver's psychological expectations under acceleration, constant speed, and deceleration conditions, thereby achieving a good auditory experience.

[0042]

[0043] Among them, g c is the current acceleration of the vehicle, g max is the maximum acceleration of the vehicle.

[0044] (4) Perform inverse Fourier transform on each frequency sound and accumulate it to obtain the active sound wave audio signal y out , see formula (4) for details.

[0045] y out =a g ×∑(ifft(a fn ×f n )) (4)

[0046] S2, determine the spatial position of the active sound wave.

[0047] The spatial coordinates of the sound wave within the vehicle are determined based on the vehicle's navigation direction and intersection distance. A plane polar coordinate system is established within the vehicle, with the vehicle's center point as the origin. The polar coordinates p(r,θ) of the sound wave within this plane polar coordinate system are calculated as follows.

[0048] The calculation formula for the polar diameter r of the sound wave in the plane polar coordinate system is shown in formula (5).

[0049] r=1-e -d (5)

[0050] Among them, e is the natural logarithm, d is the distance between the navigation intersection and the vehicle, which is given by the navigation software, d∈(0,+∞), so r∈(0,1).

[0051] The polar angle θ of the sound wave in the plane polar coordinate system is the actual navigation direction, which is given by the navigation software. Turning right, going straight, turning left, and turning around are mapped to the polar coordinate system at 0°, 90°, 180°, and 270°, respectively. The remaining navigation directions are generated by angle interpolation.

[0052] There are multiple speakers arranged in the car. In the polar coordinate system, the minimum distance between each speaker and the center point of the car is set to 1, which is the unit length of the polar coordinate system. This ensures that the sound wave position does not exceed the area formed by the sequential connection of each speaker. In this embodiment, Figure 2As shown, four speakers are provided, namely speakers S1, S2, S3, and S4, which are respectively located on the left and right sides of the front and the left and right sides of the rear of the vehicle. The four speakers are connected in sequence to form a rectangular structure, with the pole located at the center of the rectangular structure formed by the four speakers. The arrangement of the speakers in the vehicle is not limited to that shown in this embodiment.

[0053] S3, active sound wave multi-channel rendering.

[0054] The sound intensity localization method is used to distribute and render the generated active sound wave audio in the multi-channel speakers, which specifically includes the following steps.

[0055] (1) Calculate the Euclidean distance d between the sound wave spatial position p(r,θ) and each speaker pm , d pm The calculation method of is shown in formula (6).

[0056]

[0057] Among them, m is the speaker number, s m (r m ,θ m ) is the polar coordinate of the m-th loudspeaker in the polar coordinate system.

[0058] (2) According to d pm Calculate the audio gain coefficient g of each speaker channel pm , g pm The calculation method of is shown in formula (7).

[0059] g pm =1 / d pm (7)

[0060] (3) The audio gain coefficient g for each speaker channel pm Perform equalization processing to ensure the stability of the overall output power of the active sound wave.

[0061] The audio gain coefficient g of each speaker channel after equalization pm-nom The calculation method of is shown in formula (8).

[0062]

[0063] Where z is the total number of speakers.

[0064] (4) The audio gain coefficient g of each speaker channel after equalization is pm-nom The active sound audio signal y obtained in step S1 out By multiplying them together, we can obtain the final sound wave audio signal output by each speaker channel.

[0065] In this way, the generation of the active sound wave audio signal of the multi-channel speaker is completed. This application maps the navigation direction and intersection distance into the spatial coordinates inside the vehicle, and uses the sound intensity positioning method to position and play the active sound wave sound through the multi-channel speaker inside the vehicle, so that the in-vehicle listening position of the active sound wave sound changes in real time with the change of the navigation direction and intersection distance, integrating the navigation information and the active sound wave sound, and solving the problem that the active sound wave sound interferes with the navigation broadcast sound and affects the driver's judgment of the navigation direction and intersection distance. Compared with the method of playing the navigation sound at a lowered sound level, the continuity and consistency of the sound wave sound are maintained, and the auditory sense of movement and pleasure are maintained. Compared with the method of directly mixing the sound wave sound and the navigation sound, the method of using sound positioning playback to provide spatial prompts for the navigation information, presents the navigation direction and intersection distance auditorily, improves driving safety, and increases the fun of the active sound wave.

[0066] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling the generation of active sound waves, characterized by: The steps include: S1, analyzes CAN signals or receives vehicle control signals through the active sound generation program to synthesize active sound audio signals; S2: Multiple speakers are placed inside the vehicle. A plane polar coordinate system is established inside the vehicle with the center point of the vehicle as the coordinate origin. Based on the vehicle's navigation direction and the distance to the intersection, the polar coordinates p(r,θ) of the sound wave in the plane polar coordinate system are calculated, including: The minimum distance between each speaker and the center point of the vehicle is set to 1, a unit length of the polar coordinate system; The calculation formula for the polar diameter r of the sound wave in the plane polar coordinate system is: r = 1-e -d , where e is the natural logarithm and d is the distance between the navigation intersection and the vehicle; The polar angle θ of the sound wave in the plane polar coordinate system is the navigation direction, which is given by the navigation software. Turning right, going straight, turning left, and turning around are mapped to 0°, 90°, 180°, and 270° respectively. The remaining navigation directions are generated by angle interpolation. S3, determining the sound wave audio signal finally output by each of the speaker channels, comprising the following steps: (1) Calculate the Euclidean distance d between the sound wave spatial position p(r,θ) and each of the loudspeakers pm ; (2) Calculate the audio gain coefficient g of each speaker channel pm ; (3) The audio gain coefficient g of each speaker channel is pm Perform equalization processing; (4) multiplying the audio gain coefficient of each speaker channel after equalization processing by the active sound audio signal obtained in step S1 to obtain the sound audio signal finally output by each speaker channel; d pm The calculation formula is: Among them, m is the speaker number, s m (r m ,θ m ) is the polar coordinate of the m-th loudspeaker; g pm The calculation formula is: g pm =1 / d pm ; The audio gain coefficient g of each speaker channel after equalization processing pm-nom The calculation formula is: Where z is the total number of speakers.

2. The active sound wave control method according to claim 1, characterized in that: Step S1 includes the following steps: (1) Set the motor speed r m and the speed r of the internal combustion engine or e , order n, and obtain multiple sound frequency values ​​f of the sound wave to be synthesized n , f n =r m ×r e-max / r m-max ×n, where r e-max is the maximum speed of the internal combustion engine or engine, r m-max is the maximum speed of the motor, n is a positive integer less than 5; (2) Compare the accelerator pedal or throttle opening p with the preset maximum sound pressure amplitude a of each order. n-max Match and get the amplitude information a of each frequency sound fn , a fn =p×r m / r m-max ×a n-max ; (3) Adjust the overall acceleration amplitude gain a of the sound wave g , when the vehicle's current acceleration g c >0, a g =g c / g max , g max is the maximum acceleration of the vehicle; when the vehicle's current acceleration g c When ≤0, a g =0; (4) Perform inverse Fourier transform on each frequency sound and accumulate it to obtain the active sound wave audio signal y out ,y out =a g ×Σ(ifft(a fn ×f n )).

3. The active sound wave control method according to claim 1, characterized in that: There are four speakers, which are respectively arranged on the left and right sides of the front part and the left and right sides of the rear part of the vehicle.

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