阅读说明：本技术 一种基于轨道机车的局部空间有源噪声控制系统 (Local space active noise control system based on rail locomotive ) 是由 代海 张亚洲 玉昊昕 李�荣 吴凡 袁梦囝 孟堃 汪杰 于 2020-08-03 设计创作，主要内容包括：本发明公开了一种基于轨道机车的局部空间有源噪声控制系统,涉及噪声控制技术领域,包括有源控制器、控制盒、误差传声器、参考传声器和次级声源。本发明通过采集初级噪声目标控制区域的噪声信号,并将噪声信号转换为电信号输送至有源控制器获取与初级噪声信号大小相同相位相反的反相次级噪声,实现与初级噪声相互抵消以达到降噪目的,不仅降低车体噪声优化成本代价,对低频噪声进行了有效控制,而且控制系统体积小,便于安装,布局以对称美观并兼顾噪声控制效果的前提下进行布放,不影响司机的正常操作区域和乘员的活动区域,改善司机和乘员的噪声环境,提高人员乘坐轨道机车的舒适性。(The invention discloses a local space active noise control system based on a rail locomotive, which relates to the technical field of noise control and comprises an active controller, a control box, an error microphone, a reference microphone and a secondary sound source. The invention acquires the noise signal of the primary noise target control area, converts the noise signal into an electric signal and transmits the electric signal to the active controller to acquire the reversed-phase secondary noise with the same size and the opposite phase with the primary noise signal, thereby realizing the purpose of noise reduction by mutually offsetting the noise signal with the primary noise, not only reducing the cost of optimizing the vehicle body noise and effectively controlling the low-frequency noise, but also having small volume of the control system, convenient installation, symmetrical and beautiful layout and laying under the premise of considering the noise control effect, not influencing the normal operation area of a driver and the activity area of passengers, improving the noise environment of the driver and the passengers and improving the comfort of the passengers riding a rail locomotive.)

1. A local space active noise control system based on a rail locomotive is characterized by comprising an active controller (1), a control box (2), an error microphone (3), a reference microphone (4) and a secondary sound source (5), wherein;

the error microphone (3) is used for acquiring a noise signal of a primary noise target control area, converting the noise signal into an electric signal and transmitting the electric signal to the active controller (1) to be used as a noise input signal of the active controller (1);

the reference microphone (4) is used for selecting an acoustic signal as a reference for the type of the track locomotive reference signal, converting the reference acoustic signal into an electric signal and then transmitting the electric signal to the active controller (1) as a reference signal of the active controller (1);

the active controller (1) receives and processes the acquired primary noise signal and the reference signal to acquire the inverse secondary noise with the same size and the same phase as the primary noise signal;

the control box (2) is used for providing service support as an external control device;

and the secondary sound source (5) is used for reproducing the acquired reversed phase secondary noise with the same size and the opposite phase as the primary noise signal, and realizing mutual cancellation with the primary noise so as to achieve the purpose of noise reduction.

2. The rail locomotive based local space active noise control system according to claim 1, characterized in that the active controller (1) comprises an adaptive algorithm system integrated by FPGA and DSP modules for adaptive calculation of the acquired primary noise signal and the reference signal.

3. The rail locomotive-based local space active noise control system of claim 1, wherein the adaptive algorithm comprises the FxLMS algorithm, the fullms algorithm, and the FeLMS algorithm.

4. The rail-based locomotive local space active noise control system according to claim 3, characterized in that said active controller (1) and said control box (2) are fitted under the seat of the rail-based locomotive.

5. Local space active noise control system based on rail locomotives according to claim 4, characterized in that said secondary sound source (5) is fitted above the headrest of the rail locomotive.

6. Local space active noise control system based on rail locomotives according to claim 5, characterized in that said error microphone (3) is fitted above said secondary sound source (5).

Technical Field

The invention relates to the technical field of noise control, in particular to a local space active noise control system based on a rail locomotive.

Background

With the vigorous construction of urbanization in China, urban rail transit is developed rapidly, rail locomotive systems such as subways and high-speed rails are undoubtedly important roles of the urban rail transit systems, and for the large established rail locomotive transport network, passenger flow, running speed, density and the like are continuously enlarged, so that the noise problem brought by the expansion is more and more prominent. The noise problem of the rail locomotive mainly refers to two aspects, namely the noise of medium-high frequency components on one hand and the noise of low-frequency components on the other hand. The noise harm is various and subtler, and the noise harm stimulates the nervous system, the cardiovascular system, the blood pressure and the like of a human body under a noise environment for a long time to cause various complications such as chest distress, heart rate fluctuation, nervous tension, tinnitus deafness, memory deterioration, abnormal blood pressure and the like, and particularly, low-frequency noise has a larger influence on the health of the human body, so the noise problem of the rail locomotive must be fully valued and solved.

The noise control is to reduce the sound pressure level of the target area, improve the subjective feeling of the human ear, and improve the comfort level. The noise control technology is mainly divided into a traditional passive noise control technology and a novel active noise control technology, the passive noise control technology mainly comprises traditional noise control technologies such as sound absorption and insulation, muffler design, structural acoustic design optimization and acoustic material addition, control is mainly focused on medium-high frequency noise above 800Hz, the active noise control technology is a new noise control branch at present and is better at controlling low-frequency noise below 800Hz, the principle is that the destructive interference principle of sound waves is utilized, reverse noise (secondary sound field) for offsetting a noise source (primary sound field) is artificially generated, and the purpose of sound elimination is achieved.

The existing noise control technology of the rail locomotive traffic system is applied to the traditional passive noise control technology, and particularly for the built huge transport network, the cost is very high through structural acoustic optimization, vehicle body structure modification, final assembly and the like. The problem of low-frequency noise in the railway locomotive is increasingly prominent, and the problem cannot be effectively solved through a traditional passive noise reduction mode.

An effective solution to the problems in the related art has not been proposed yet.

Disclosure of Invention

The invention provides a local space active noise control system based on a rail locomotive, aiming at the problems in the related art and aiming at overcoming the technical problems in the prior related art.

The technical scheme of the invention is realized as follows:

a local space active noise control system based on a rail locomotive comprises an active controller, a control box, an error microphone, a reference microphone and a secondary sound source, wherein the active controller is connected with the control box;

the error microphone is used for acquiring a noise signal of a primary noise target control area, converting the noise signal into an electric signal and transmitting the electric signal to the active controller to serve as a noise input signal of the active controller;

the reference microphone is used for selecting an acoustic signal as a reference for the type of the track locomotive reference signal, converting the reference acoustic signal into an electric signal and then transmitting the electric signal to the active controller to be used as a reference signal of the active controller;

the active controller receives and processes the acquired primary noise signal and the reference signal to acquire the inverse secondary noise with the same size and the same phase as the primary noise signal;

the control box is used as external control equipment to provide service support;

the secondary sound source is used for reproducing the acquired reversed phase secondary noise which has the same size and the opposite phase with the primary noise signal, and the primary noise and the secondary sound source are mutually offset to achieve the purpose of noise reduction.

Further, the active controller comprises an adaptive algorithm system integrated by an FPGA module and a DSP module and used for carrying out adaptive calculation on the acquired primary noise signal and the reference signal.

Further, the adaptive algorithm includes an FxLMS algorithm, a fullms algorithm, and a femlms algorithm.

Further, the active controller and the control box are mounted under a seat of the rail locomotive.

Further, the secondary sound source is mounted above a headrest of the rail vehicle.

Further, the error microphone is mounted above the secondary sound source.

The invention has the beneficial effects that:

the invention is based on the active noise control system of local space of the rail locomotive, through gathering the noise signal of the primary noise target control area, and convert the noise signal into the electrical signal and transmit the electrical signal to the active controller and obtain the opposite phase secondary noise with the same size and opposite phase of the primary noise signal, realize and cancel each other with the primary noise in order to achieve the goal of reducing noise, not only reduce the optimization cost of the car body noise, has carried on the effective control to the low-frequency noise, and the control system is small, easy to install, the overall arrangement is carried on the premise of symmetrical esthetic and giving consideration to the noise control effect, does not influence normal operating area and passenger's activity area of the driver, improve the noise environment of driver and passenger, improve the person and take the comfortableness of the.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a functional block diagram of a local space active noise control system for a rail-based locomotive, according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an active controller of a local space active noise control system based on a rail vehicle according to an embodiment of the present invention;

FIG. 3 is a first schematic assembly diagram of a rail locomotive based localized space active noise control system according to an embodiment of the present invention;

FIG. 4 is a second schematic assembly diagram of a local space active noise control system for a rail-based locomotive, according to an embodiment of the present invention;

FIG. 5 is a schematic view of a scenario of a rail locomotive based localized spatial active noise control system according to an embodiment of the present invention;

fig. 6 is a schematic flow diagram of a local space active noise control system based on a rail vehicle according to an embodiment of the present invention.

In the figure:

1. an active controller; 2. a control box; 3. an error microphone; 4. a reference microphone; 5. a secondary sound source.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the 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 that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

According to an embodiment of the present invention, a rail locomotive based local space active noise control system is provided.

As shown in fig. 1-2, a local spatial active noise control system for a rail-based locomotive according to an embodiment of the present invention includes an active controller 1, a control box 2, an error microphone 3, a reference microphone 4, and a secondary sound source 5, wherein;

the error microphone 3 is used for acquiring a noise signal of a primary noise target control area, converting the noise signal into an electric signal and transmitting the electric signal to the active controller 1 to be used as a noise input signal of the active controller 1;

the reference microphone 4 is used for selecting an acoustic signal as a reference for the type of the track locomotive reference signal, converting the reference acoustic signal into an electric signal and then transmitting the electric signal to the active controller 1 as a reference signal of the active controller 1;

the active controller 1 receives and processes the acquired primary noise signal and the reference signal to acquire the inverse secondary noise with the same size and the same phase as the primary noise signal;

the control box 2 is used as an external control device to provide service support;

and the secondary sound source 5 is used for replaying the acquired reversed-phase secondary noise which has the same size and the opposite phase with the primary noise signal, and offsetting the primary noise to achieve the purpose of reducing the noise.

The active controller 1 comprises an adaptive algorithm system integrated by an FPGA module and a DSP module and used for carrying out adaptive calculation on the acquired primary noise signal and the reference signal.

The adaptive algorithm comprises an FxLMS algorithm, a FuLMS algorithm and a FeLMS algorithm.

Wherein the active controller 1 and the control box 2 are mounted under a seat of a rail vehicle.

Wherein the secondary sound source 5 is mounted above the headrest of the rail vehicle.

Wherein the error microphone 3 is mounted above the secondary sound source 5.

By means of the technical scheme, the noise signal of the primary noise target control area is collected, the noise signal is converted into the electric signal and is transmitted to the active controller to obtain the reversed-phase secondary noise which is the same as the primary noise signal in size and opposite in phase, the purpose of noise reduction is achieved by mutual offset with the primary noise, not only is the cost of vehicle body noise optimization cost reduced, the low-frequency noise is effectively controlled, but also the control system is small in size and convenient to install, the arrangement is carried out on the premise that the arrangement is symmetrical and attractive and the noise control effect is considered, the normal operation area of a driver and the activity area of passengers are not affected, the noise environment of the driver and the passengers is improved, and the comfort of the passengers on the rail.

In addition, the working principle of the active control system equipment in the local space of the rail locomotive is as follows: the working principle of the local space active control system equipment is as follows: all secondary sound sources and error microphones are fixed at different positions of a local space target control area, the error microphones are used for collecting primary noise signals of the subway, signal processing is carried out through a controller self-adaptive algorithm, the signals are output to the secondary sound sources to emit secondary noise, and anti-phase noise is generated to achieve the purpose of sound elimination, so that a 'silent area' is formed in a local space, the noise environment is improved, and the comfort of passengers is improved.

In addition, specifically, as shown in fig. 3 to 5, the installation position of the active controller is selected to be located behind the under-seat support member at the lower part of the seat in consideration of the local space limitation and the normal movement of the person; the installation position of the control box is arranged on the side surface of the active controller without a cable interface, the control box is generally in a noise control mode (or called as a 'noise reduction opening mode') in the whole process of the running process of the rail car, the operation frequency is not high under the general condition, and the noise control state is detected; the installation position of the error microphone refers to the layout mode of the electroacoustic device; the mounting position of the reference microphone is positioned in a noise reduction control target area and two side areas of human ears, 2 reference sound microphones are selected, and the spatial arrangement is kept symmetrical; in addition, the selection position of the reference signal of the rail locomotive noise local space active noise control system is as follows: close to the two sides of the human ear, the schematic view of the installation position is shown in fig. 5.

In addition, specifically, the method for testing the noise reduction effect of the noise control area of the rail locomotive comprises the following steps: the noise reduction effect test method of the rail locomotive needs to be selected according to the type of the locomotive, the station interval time and the like. If the train is a high-speed rail system, when the train runs in a constant speed state, measuring the background noise before 60s of control, starting a noise control mode, measuring the background noise after 60s of control, and subtracting the background noise and the background noise to obtain the noise reduction of a control area. If the system is a subway system, the noise reduction effect cannot be judged through the same measuring point because the rail locomotive has three states of acceleration, uniform speed and deceleration in the process of running between stations, and the sound pressure level fluctuation obtained by continuous measurement between the two stations is large. The objective effect test method comprises the following steps: two groups of noise measuring points with the same height and relative position are artificially set at two positions with the similar train distance, the same internal arrangement and the same train body structure, one group is used as a noise background reference measuring point, the other group is used as an effect measuring point of an active noise control area, the reference measuring point is used as a noise before control, the effect measuring point is used as a noise after control, the noise before control and the noise after control are simultaneously measured, and the average noise reduction of the control area is obtained by subtracting the two.

As shown in fig. 6, the adaptive algorithm mainly includes FxLMS, fullms, and FeLMS. The algorithm of the control system is characterized in that a feedforward and feedback composite control mode is selected, and secondary path delay compensation and secondary sound source-reference signal acoustic feedback cancellation are added at the same time. Because a noise source is used as a reference signal, when the control system performs control, the secondary noise is inevitably picked up by the reference microphone to form a feedback loop, so that the system generates a divergence or howling phenomenon. The control system performs cancellation and inhibition on a feedback loop of the secondary sound source-reference signal in the self-adaptive algorithm, ensures the stability of the system, performs delay compensation on the secondary signal, and improves the control effect of the system on noise.

In addition, the active noise control system equipment in the local space of the rail locomotive realizes the application of the technical scheme and is feasible to verify; the control system has small volume and convenient installation, is distributed on the premise of symmetrical and beautiful layout and considering the noise control effect, and does not influence the normal operation area of a driver and the activity area of passengers; at present, the system has completed an effect verification test on a certain rail locomotive, the low-frequency noise reduction index of a local area is obvious, and the noise reduction of an active area of the head of a human ear measuring point reaches 4.8dB (A). The local space active control technology can greatly reduce the cost of vehicle body noise optimization, and the low-frequency noise adaptive control is carried out in a 'more and more complicated' mode to form good 'complementation' with passive noise control, thereby optimizing the noise problem of the rail locomotive; the system is greatly harmful to human health when being in a low-frequency noise environment for a long time, effectively controls low-frequency noise, improves the noise environment of drivers and passengers, and improves the comfort of the passengers riding on the rail locomotive.

In summary, according to the technical scheme of the present invention, the noise signal of the primary noise target control area is collected, converted into the electrical signal, and transmitted to the active controller to obtain the inverted secondary noise with the same size and the opposite phase as the primary noise signal, so as to achieve the purpose of noise reduction by offsetting the primary noise with each other, thereby not only reducing the cost of vehicle body noise optimization and effectively controlling the low-frequency noise, but also reducing the volume of the control system, facilitating installation, and laying out the control system on the premise of symmetry, beauty and noise control effect, without affecting the normal operation area of the driver and the activity area of the passenger, improving the noise environment of the driver and the passenger, and improving the comfort of the passenger on the track locomotive.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.