In-vehicle compressor noise reduction method and system based on self-adaptive control

Abstract

The invention relates to an in-vehicle compressor noise reduction method and system based on self-adaptive control, and belongs to the field of noise control. The method comprises the following steps: acquiring a compressor fundamental frequency and a compressor noise main frequency spectrum based on offset compensation; obtaining a dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main frequency spectrum; constructing an amplitude adaptive function based on the dynamic frequency weight coefficient and the compressor noise main frequency spectrum; and according to the amplitude adaptive function, defining a sound wave interference matrix for controlling the noise of the compressor in the vehicle. According to the method, dynamic frequency domain tracking, multi-area sound field coupling and high-flexibility regulation and control are realized, the noise of the compressor in the vehicle is accurately suppressed, and the user experience is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of noise control, and in particular relates to a method and system for reducing noise of a vehicle compressor based on adaptive control. Background Art

[0002] With the popularity of electric vehicles and hybrid vehicles, in-vehicle noise control technology faces new challenges. After the noise of traditional internal combustion engines is suppressed, compressor noise (especially the scroll compressor and high-frequency solenoid valve noise of the thermal management system) has become the main contradiction affecting NVH (noise, vibration and harshness) performance. The early compressor noise reduction scheme was based on the design of FIR notch filter based on the offline measured compressor characteristic frequency, and the noise reduction was achieved by emitting anti-phase sound waves through the speaker, but this technology has significant defects: Band rigidity: It can only process the fundamental frequency noise at a constant speed. When the vehicle accelerates suddenly or the compressor load changes suddenly, the measured frequency offset is large, resulting in attenuation of the noise reduction. Poor spatial generalization ability: With a single microphone-single speaker architecture, the noise suppression in the rear row is insufficient, and the noise reduction in the front row will cause the sound pressure level in the rear row to increase. Weak universality: Factors such as compressor mechanical wear, background noise, dynamic smoothing coefficient and phase compensation are not considered, resulting in poor universality of the scheme and inability to adjust adaptively. Summary of the invention

[0003] In order to solve the above problems existing in the prior art, the present invention provides a method and system for reducing the noise of a vehicle compressor based on adaptive control.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for reducing noise of a vehicle compressor based on adaptive control, the implementation of the method for reducing noise of a vehicle compressor includes the following steps: Acquire the compressor fundamental frequency and the main spectrum of the compressor noise based on the offset compensation; Obtaining a dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main spectrum; Constructing an amplitude adaptive function based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise; A sound wave interference matrix is ​​defined according to the amplitude adaptive function to control the noise of the compressor in the vehicle.

[0005] Preferably, the acquisition of the compressor fundamental frequency and the compressor noise main spectrum includes: The real-time speed and number of compressor blades of the vehicle compressor are collected and the fundamental frequency of the compressor is calculated. The calculation formula is: , where f c (t) is the compressor base frequency at time t, RPM(t) is the real-time speed of the compressor at time t, k is the number of compressor blades, is the compensation offset term; Establish a three-zone sound field monitoring network, divide the interior area into the main driver area, the co-driver area and the rear seat area, capture the compressor noise signal and convert it into a real-time noise spectrum, the real-time noise spectrum includes the main driver real-time noise spectrum, the co-driver real-time noise spectrum and the rear seat real-time noise spectrum; A background noise spectrum is captured, and the main spectrum of the compressor noise is obtained based on the real-time noise spectrum and the background noise spectrum.

[0006] Preferably, the acquisition of the dynamic frequency weight coefficient includes: Adaptively controlling a dynamic smoothing coefficient according to the real-time speed of the in-vehicle compressor; The dynamic frequency weight coefficient is calculated based on the dynamic smoothing coefficient and the compressor fundamental frequency.

[0007] Preferably, the calculation formula of the dynamic frequency weight coefficient is: , where W(t,i) is the dynamic frequency weight coefficient of region i at time t, α(t) is the dynamic smoothing coefficient at time t, f(t,i) is the frequency of the compressor noise signal in region i at time t, and i is 1, 2, and 3, corresponding to the main driver area, the co-driver area, and the rear area, respectively.

[0008] Preferably, the construction of the amplitude adaptive function includes: Calibrate the phase calibration value and obtain the structural vibration transmission time and transmission distance, wherein the transmission distance includes the transmission distance for the main driver, the transmission distance for the co-driver and the transmission distance for the rear seat; calculating a phase compensation value based on the structural vibration transmission time and the transmission distance; Acquire a throttle depth, and obtain a dynamic gain coefficient based on the throttle depth; An amplitude adaptive function is constructed based on the phase compensation value, the dynamic frequency weight coefficient, the compressor noise main spectrum and the dynamic gain coefficient.

[0009] Preferably, the calculation formula of the phase compensation value is: ,in, is the phase compensation value of region i at time t, d i is the transmission distance of area i, c is the speed of sound, is the structural vibration transfer time, is the phase calibration value.

[0010] Preferably, the calculation formula of the dynamic gain coefficient is: ,in, is the dynamic gain coefficient at time t, and Acc(t) is the throttle depth at time t.

[0011] Preferably, the mathematical description of the amplitude adaptive function is , where A anti (t,i) is the amplitude adaptive function of region i at time t, N comp (t,i) is the main spectrum of the compressor noise in region i at time t.

[0012] Preferably, the mathematical description of the acoustic wave interference matrix is , where A left To interfere with the sound wave, A right Interference sound waves for the co-pilot, A rear is the rear interference sound wave, A anti (t,1) is the amplitude adaptive function of the main driving area at time t, A anti (t,2) is the amplitude adaptive function of the co-pilot area at time t, A anti (t,3) is the amplitude adaptive function of the rear area at time t.

[0013] An in-vehicle compressor noise reduction system based on adaptive control, used to implement the in-vehicle compressor noise reduction method described above, comprising a weight extraction module, an adaptive function construction module and an acoustic wave interference module; The weight extraction module is used to obtain the compressor fundamental frequency and the compressor noise main spectrum based on the offset compensation; and obtain the dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main spectrum; The adaptive function building module is used to build an amplitude adaptive function based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise; The acoustic wave interference module is used to define an acoustic wave interference matrix according to the amplitude adaptive function for controlling the noise of the compressor in the vehicle.

[0014] The beneficial effects of the present invention are: (1) By establishing a three-zone sound field monitoring network, the spatial sound field decoupling control is realized, the noise is adaptively controlled in different zones, the spatial generalization ability is strong, and the noise reduction accuracy and efficiency are significantly improved.

[0015] (2) By comprehensively considering parameters such as the compensation offset term, background noise spectrum, dynamic smoothing coefficient, phase compensation value, and dynamic gain coefficient, the noise under various working conditions can be processed, the universality of the solution can be improved, and adaptive adjustment and control of the compressor noise in the vehicle can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0017] Figure 1 The present invention is a flowchart of the steps of a method for reducing noise of a vehicle compressor based on adaptive control. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0019] The working principle and use process of the present invention: See also Figure 1 , a method for reducing noise of a compressor in a vehicle based on adaptive control, comprising: S1: Obtaining the compressor fundamental frequency and the main spectrum of the compressor noise based on offset compensation; S2: obtaining a dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main spectrum; S3: constructing an amplitude adaptive function based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise; S4: According to the amplitude adaptive function, a sound wave interference matrix is ​​defined to control the noise of the compressor in the vehicle, which is mathematically described as: , where A left To interfere with the sound wave, A right Interference sound waves for the co-pilot, A rear is the rear interference sound wave, A anti (t,1) is the amplitude adaptive function of the main driving area at time t, A anti (t,2) is the amplitude adaptive function of the co-pilot area at time t, A anti (t,3) is the amplitude adaptive function of the rear area at time t; when it is substituted into the matrix formula, the interference sound wave in the rear area is -0.05A. anti (t,1)-0.05A anti (t,2)+0.8A anti (t,3), that is, when controlling the rear row noise, 80% is for the rear row local noise, and 5% of the interference sound from the front row is deducted.

[0020] In this embodiment, the compressor fundamental frequency and the compressor noise main spectrum are obtained based on the offset compensation, which can be implemented by the following steps: S101: Collect the real-time rotation speed and number of compressor blades in the vehicle and calculate the compressor fundamental frequency. The calculation formula is: , where f c (t) is the compressor fundamental frequency at time t, RPM(t) is the real-time speed of the compressor in the vehicle at time t, the unit is revolutions per minute, k is the number of compressor blades, dimensionless, It is the compensation offset item, which is used to compensate for the fundamental frequency offset caused by mechanical wear of the compressor (for example, if the blades of an old car are deformed and the measured fundamental frequency is 5Hz lower than the theoretical value, the compensation offset item is set to ±5Hz); S102: Establishing a three-zone sound field monitoring network, dividing the vehicle interior into a main driver's seat area, a co-driver's seat area, and a rear seat area, capturing compressor noise signals through microphones arranged in different areas and converting them into real-time noise spectra through fast Fourier transformation, wherein the real-time noise spectrum includes a main driver's seat real-time noise spectrum, a co-driver's seat real-time noise spectrum, and a rear seat real-time noise spectrum; S103: Capturing the background noise spectrum, that is, when the compressor is not started, recording the noise inside the vehicle as the background noise spectrum, and obtaining the main spectrum of the compressor noise based on the real-time noise spectrum and the background noise spectrum, which can be mathematically described as: , where N comp (t,i) is the main spectrum of the compressor noise in region i at time t, N raw (t,i) is the real-time noise spectrum of region i at time t, N bg (t,i) is the background noise spectrum of area i at time t, i is 1, 2, 3, corresponding to the main driver area, the co-driver area and the rear area respectively, and the coefficient 0.7 is used to prevent excessive subtraction and retain sudden environmental noise.

[0021] In this embodiment, the dynamic frequency weight coefficient is obtained according to the compressor fundamental frequency and the compressor noise main spectrum, which can be implemented by the following steps: S201: Adaptively control the dynamic smoothing coefficient according to the real-time speed of the in-vehicle compressor, which is mathematically described as , where α(t) is the dynamic smoothing coefficient at time t. When the vehicle is traveling at a constant speed, the real-time speed change rate of the in-vehicle compressor is 0, and α(t) is 0.01. When the vehicle accelerates suddenly (the real-time speed change rate of the in-vehicle compressor is 500 rpm), α(t) is 0.0125. S202: Calculate the dynamic frequency weight coefficient based on the dynamic smoothing coefficient and the compressor base frequency. The calculation formula is: , where W(t,i) is the dynamic frequency weight coefficient of region i at time t, and f(t,i) is the frequency of the compressor noise signal in region i at time t.

[0022] In this embodiment, the amplitude adaptive function is constructed based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise, which can be implemented by the following steps: S301: Calibrate phase calibration values ​​of different vehicle models in a laboratory and obtain structural vibration transmission time and transmission distance, where the transmission distance is the distance between the microphone and the corresponding area inside the vehicle, and includes the transmission distance of the driver's seat, the transmission distance of the co-driver's seat, and the transmission distance of the rear seat, that is, the distance between the microphone arranged on the driver's seat and the driver's headrest, and so on; S302: Calculate the phase compensation value, the calculation formula is: ,in, is the phase compensation value of region i at time t, d i is the transmission distance of area i, c is the speed of sound, is the structural vibration transfer time, is the phase calibration value. For example, if the transmission distance of the main driving area is 0.3m, for 160Hz noise, the phase compensation value of the main driving area can be obtained as 2π×160×[(0.3 / 343)+ ]+ ≈0.88π, which is equivalent to controlling the noise in the main driving area by 0.88π phase advance; S303: Acquire the throttle depth, and obtain a dynamic gain coefficient based on the throttle depth. The calculation formula is: ,in, is the dynamic gain coefficient at time t, and Acc(t) is the throttle depth at time t, with the unit of %. For example, when the driver steps on the throttle to accelerate by 40%, the dynamic gain coefficient is 1.08, and the system increases the noise reduction strength by an additional 8% to offset the additional noise generated by the compressor due to the increased load. S304: constructing an amplitude adaptive function based on the phase compensation value, the dynamic frequency weight coefficient, the compressor noise main spectrum and the dynamic gain coefficient, which is mathematically described as: , where A anti (t,i) is the amplitude adaptive function of region i at time t.

[0023] A vehicle compressor noise reduction system based on adaptive control, comprising a weight extraction module, an adaptive function construction module and a sound wave interference module; The weight extraction module is used to obtain the compressor fundamental frequency and the compressor noise main spectrum based on the offset compensation; and obtain the dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main spectrum; The adaptive function building module is used to build an amplitude adaptive function based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise; The acoustic wave interference module is used to define an acoustic wave interference matrix according to the amplitude adaptive function to control the noise of the compressor in the vehicle, which is mathematically described as , where A left To interfere with the sound wave, A right Interference sound waves for the co-pilot, A rear is the rear interference sound wave, A anti (t,1) is the amplitude adaptive function of the main driving area at time t, A anti (t,2) is the amplitude adaptive function of the co-pilot area at time t, A anti (t,3) is the amplitude adaptive function of the rear area at time t.

[0024] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device.

[0025] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0026] The program code included on the computer readable medium can be transmitted with any appropriate medium, including but not limited to wireless, electric wire, optical cable, RF, etc., or any suitable combination of the above. The computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or their combinations, and the programming language includes object-oriented programming languages-such as Java, Smalltalk, C++, and also includes conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0027] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for reducing noise of a vehicle compressor based on adaptive control, characterized in that: The implementation of the method for reducing the noise of the compressor in the vehicle comprises the following steps: Acquire the compressor fundamental frequency and the main spectrum of the compressor noise based on the offset compensation; Obtaining a dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main spectrum; Constructing an amplitude adaptive function based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise; A sound wave interference matrix is ​​defined according to the amplitude adaptive function to control the noise of the compressor in the vehicle.

2. The method for reducing the noise of a compressor in a vehicle according to claim 1, characterized in that: The acquisition of the compressor fundamental frequency and the compressor noise main spectrum includes: The real-time speed and number of compressor blades of the vehicle compressor are collected and the fundamental frequency of the compressor is calculated. The calculation formula is: , where f c (t) is the compressor base frequency at time t, RPM(t) is the real-time speed of the compressor at time t, k is the number of compressor blades, is the compensation offset term; Establish a three-zone sound field monitoring network, divide the interior area into the main driving area, the co-pilot area and the rear area, capture the compressor noise signal and convert it into a real-time noise spectrum; A background noise spectrum is captured, and the main spectrum of the compressor noise is obtained based on the real-time noise spectrum and the background noise spectrum.

3. The method for reducing the noise of a compressor in a vehicle according to claim 2, characterized in that: The acquisition of the dynamic frequency weight coefficient includes: Adaptively controlling a dynamic smoothing coefficient according to the real-time speed of the in-vehicle compressor; The dynamic frequency weight coefficient is calculated based on the dynamic smoothing coefficient and the compressor fundamental frequency.

4. The method for reducing the noise of a compressor in a vehicle according to claim 3, characterized in that: The calculation formula of the dynamic frequency weight coefficient is: , where W(t,i) is the dynamic frequency weight coefficient of region i at time t, α(t) is the dynamic smoothing coefficient at time t, f(t,i) is the frequency of the compressor noise signal in region i at time t, and i is 1, 2, and 3, corresponding to the main driver area, the co-driver area, and the rear area, respectively.

5. The method for reducing the noise of a compressor in a vehicle according to claim 4, characterized in that: The construction of the amplitude adaptive function includes: Calibrate the phase calibration value and obtain the structural vibration transmission time and transmission distance, wherein the transmission distance includes the transmission distance for the main driver, the transmission distance for the co-driver and the transmission distance for the rear seat; calculating a phase compensation value based on the structural vibration transmission time and the transmission distance; Acquire a throttle depth, and obtain a dynamic gain coefficient based on the throttle depth; An amplitude adaptive function is constructed based on the phase compensation value, the dynamic frequency weight coefficient, the compressor noise main spectrum and the dynamic gain coefficient.

6. The method for reducing the noise of a compressor in a vehicle according to claim 5, characterized in that: The calculation formula of the phase compensation value is: ,in, is the phase compensation value of region i at time t, d i is the transmission distance of area i, c is the speed of sound, is the structural vibration transfer time, is the phase calibration value.

7. The method for reducing noise of a compressor in a vehicle according to claim 6, characterized in that: The calculation formula of the dynamic gain coefficient is: ,in, is the dynamic gain coefficient at time t, and Acc(t) is the throttle depth at time t.

8. The method for reducing the noise of a compressor in a vehicle according to claim 7, characterized in that: The mathematical description of the amplitude adaptation function is , where A anti (t,i) is the amplitude adaptive function of region i at time t, N comp (t,i) is the main spectrum of the compressor noise in region i at time t, and j is an imaginary unit.

9. The method for reducing noise of a compressor in a vehicle according to claim 8, characterized in that: The mathematical description of the acoustic wave interference matrix is , where A left To interfere with the sound wave, A right Interference sound waves for the co-pilot, A rear is the rear interference sound wave, A anti (t,1) is the amplitude adaptive function of the main driving area at time t, A anti (t,2) is the amplitude adaptive function of the co-pilot area at time t, A anti (t,3) is the amplitude adaptive function of the rear area at time t.

10. A vehicle compressor noise reduction system based on adaptive control, characterized in that: The system is applied to the method for reducing noise of a vehicle compressor as claimed in any one of claims 1 to 9, comprising a weight extraction module, an adaptive function construction module and an acoustic wave interference module; The weight extraction module is used to obtain the compressor fundamental frequency and the main spectrum of the compressor noise based on the offset compensation; Obtaining a dynamic frequency weight coefficient according to the compressor fundamental frequency and the compressor noise main spectrum; The adaptive function building module is used to build an amplitude adaptive function based on the dynamic frequency weight coefficient and the main spectrum of the compressor noise; The acoustic wave interference module is used to define an acoustic wave interference matrix according to the amplitude adaptive function for controlling the noise of the compressor in the vehicle.

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