Noise over-limit sound source determination method, air conditioner, vehicle, noise control method and device

Abstract

The present application firstly provides a noise over-limit sound source determination method, acquires noise through a sound acquisition device, respectively compares one or more acquired noises with standard noise, determines over-limit noise, performs octave analysis on the over-limit noise, and determines the over-limit sound source in the obtained noise frequency band. The present application further provides an air conditioner, a vehicle, a noise control method and a noise reduction device. The noise over-limit determination method, the air conditioner, the vehicle noise control method and the noise reduction device provided by the present application perform octave analysis on the over-limit noise, determine the over-limit sound source and the over-limit sound source frequency, purposefully and intelligently reduce noise aiming at the over-limit sound source, and improve the sound quality after noise reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioning products, in particular to a noise over-limit sound source determination method, an air conditioner, a vehicle, a noise control method and device. BACKGROUND

[0002] The variable frequency air conditioner adjusts the output cooling capacity by automatically adjusting the compressor operating frequency, fan speed and other methods according to the indoor set temperature and load changes such as passenger capacity, so that the indoor temperature of the passenger compartment is maintained within the set temperature range. When the indoor temperature reaches the desired value, the air conditioner compressor maintains a certain speed, and the fan adjusts the air volume and speed by adjusting the speed (i.e. the speed of the rotor parts such as the fan and the compressor is variable). Therefore, the noise value and sound spectrum emitted by the air conditioner itself are variable. Influenced by the complex environment of the vehicle running line, the noise of the vehicle compartment is also variable.

[0003] The current active noise reduction measures for rail vehicle systems are generally integrated inside the vehicle air duct or inside the vehicle compartment. The sound sensors and noise generators of the active noise reduction system are limited by the installation position and number, and cannot monitor the noise state of the variable frequency air conditioner and each rotor part inside the unit in real time. It cannot simultaneously reduce the influence of the air conditioner itself running noise and environmental noise on the inside of the vehicle compartment, affecting the ride comfort of the vehicle. When intelligent noise reduction is performed, the noise that exceeds the standard value is usually directly subjected to overall noise reduction processing. Although the noise is reduced, the noise itself and the reason for the noise exceeding the limit are not analyzed, and only the noise value is reduced as a whole, and the sound quality of the noise cannot be effectively improved. In the existing intelligent noise reduction, there is no method to determine the noise over-limit. SUMMARY

[0004] The main purpose of the present application is to solve the above problems and deficiencies. First, a noise over-limit sound source determination method is provided, which can analyze the over-limit noise and determine the noise over-limit sound source. In the intelligent noise reduction process, the over-limit sound source can be targeted for noise reduction, improving the noise reduction effect and the sound quality after noise reduction.

[0005] Another purpose of the present application is to provide an air conditioner that uses the noise over-limit sound source determination method for intelligent noise reduction, improving the sound quality of the noise after noise reduction.

[0006] A third purpose of the present application is to provide a vehicle that installs the air conditioner unit to reduce the air conditioner running noise in the vehicle.

[0007] A fourth purpose of the present application is to provide a noise control method that can control the overall noise in the vehicle.

[0008] A fifth purpose of the present application is to provide a noise reduction device that can achieve intelligent noise reduction in a targeted manner.

[0009] To achieve the above object, the present application firstly provides a noise over-limit sound source determination method, and the technical scheme is as follows:

[0010] The noise over-limit sound source determination method collects noise through a sound collecting device, compares one or more collected noises respectively with standard noise, determines over-limit noise, carries out octave analysis on the over-limit noise, and determines the over-limit sound source in the obtained noise frequency band.

[0011] Further, the following steps are adopted when analyzing the obtained over-limit noise to determine the over-limit sound source,

[0012] S1, octave analysis is carried out on the over-limit noise signal Lp collected by the sound collecting device, the corresponding f and P of Lp(f, P) of the noise are obtained, the obtained noise frequency band is calculated respectively, and the difference value of adjacent frequency bands is obtained, wherein Δ 左 =|P i-1 -P i | and Δ 右 =|P i+1 -P i |, when Δ 左 or Δ 右 is greater than a limit value, it is marked as Lp(f i1 ,P i1 ), …, Lp(f ij ,P ij ), …, Lp(f in ,P in ), wherein f represents frequency, P represents amplitude; i, j, n are natural numbers;

[0013] S2, Δ P =|MAX(P i1 ,L,P ij ,L P in )-P ij | is calculated, when Δp is greater than a predetermined value, it is removed, and the final over-limit sound source Lp(F0, P) is obtained, wherein F0 is the frequency of the over-limit sound source.

[0014] Further, the limit value of Δ 左 or Δ 右 is multiple, and is marked respectively.

[0015] Further, the limit value includes N1, N2 and N3, and the adjacent frequency band difference is divided into three grades when

[0016] When Δ 左 or Δ 右 is greater than N1, it is marked as LpH(f i1 ,P i1 ), …, LpH(f ij ,P ij ), …, LpH(fin ,P in );

[0017] When Δ 左 or Δ 右 is greater than N2 and less than or equal to N1, mark LpM(f i1 ,P i1 ), …, LpM(f ij ,P ij ), …, LpM(f in ,P in );

[0018] When Δ 左 or Δ 右 is greater than N3 and less than or equal to N2, mark LpL(f i1 ,P i1 ), …, LpL(f ij ,P ij ), …, LpL(f in ,P in );

[0019] When Δ 左 or Δ 右 is greater than 0dB and less than or equal to N3, mark Lp(f i1 ,P i1 ), …, Lp(f ij ,P ij ), …, Lp(f in ,P in );

[0020] Through step S2, three-grade over-limit sound sources and corresponding sound source frequencies Lp(F0, P) are obtained.

[0021] Further, the over-limit noise is subjected to one-third octave analysis in the range of 50Hz to 20000Hz, to obtain the frequency and amplitude of the noise, 50<(i, j, n)<20000.

[0022] The application further provides an air conditioner, adopting the following technical scheme:

[0023] An air conditioner is provided with multiple sound collecting devices to collect the running noise at each point, determine the over-limit sound source by the method described above, and set a sound source device capable of emitting an anti-phase sound source at the collecting point to reduce the over-limit sound source below the standard noise.

[0024] The third application object of the application is to provide a rail vehicle, adopting the following technical scheme:

[0025] A vehicle is provided with the air conditioner described above.

[0026] The fourth inventive objective of the present application is to provide a noise control method, which adopts the following technical scheme:

[0027] A noise control method, a plurality of sound collection devices are arranged in a space requiring noise reduction control, a sound source device is arranged at each sound collection device, each sound collection device collects real-time operating noise signals Lp at different positions and transmits them to a control device, and the noise signals Lp at each collection point are compared with the corresponding standard noise L pre-stored and recorded, wherein,

[0028] If Lp≤L, the noise collection and comparison are re-performed after a predetermined time interval;

[0029] If Lp>L, the noise is marked as an overrun noise, if the overrun noise duration is greater than T, the overrun noise is analyzed according to the method described above to determine the overrun sound source and the frequency F0 of the overrun sound source;

[0030] If Lp>L, the noise is marked as an overrun noise, if the overrun noise duration is less than or equal to T and the continuous number of times is greater than n, the overrun noise is analyzed according to the method described above to determine the overrun sound source and the frequency F0 of the overrun sound source;

[0031] If Lp>L, the noise is marked as an overrun noise, if the overrun noise duration is less than or equal to T and the continuous number of times is less than or equal to n, the noise collection and comparison are repeated;

[0032] The noise signals Lp at each collection point are compared according to the above method, and the overrun sound source frequency F0 of each noise overrun collection point is obtained, and the control device controls the corresponding sound source device to be opened according to the specific overrun sound source frequency of each collection point, emits a sound source with an opposite phase to the overrun sound source, and reduces the noise at the position.

[0033] Further, the control device is provided with an alarm device, which confirms the duration of the detected real-time noise Lp>L at each collection point, and if it is judged that the noise duration t of a certain collection point exceeds a limit value, the alarm device sends an alarm signal to the operation and maintenance system.

[0034] Further, the controller device confirms the duration of the real-time noise Lp>L at each collection point and records the overrun number of times, and when the overrun number of times is greater than a predetermined value, the alarm device sends an alarm signal to the operation and maintenance system.

[0035] The last inventive objective of the present application is to provide a noise reduction device, which adopts the following technical scheme:

[0036] The noise reduction device comprises a sound collecting device and a sound source device, the noise reduction device confirms the over-limit sound source according to the method, and the sound source device emits an inverse sound source according to the frequency of the confirmed over-limit sound source, so as to reduce noise.

[0037] In conclusion, the noise over-limit sound source determination method, the air conditioner, the vehicle, the noise control method and the device have the following beneficial effects compared with the prior art:

[0038] 1. When the noise in the vehicle is over-standard, the noise reduction measure is intelligently started, the noise reduction cost is reduced, and the vehicle riding comfort is improved.

[0039] 2. The air conditioner output noise anomaly can realize early warning and remind maintenance.

[0040] 3. When the noise in the vehicle continuously appears abnormally, early warning can be realized, and maintenance is reminded.

[0041] 4. Under the background that the air conditioner is more and more intelligent, the periodic inspection of the air conditioner noise can be effectively reduced or avoided, a more comfortable riding environment is provided, manual inspection is saved, manpower cost is saved, safety and reliability are improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The application provides a structure diagram of an air conditioner unit outdoor cavity in a rail vehicle.

[0043] Figure 2 The application provides a structure diagram of an air conditioner unit outdoor cavity in a rail vehicle.

[0044] Figure 3 The application provides a structure diagram of an air conditioner unit outdoor cavity in a rail vehicle.

[0045] Figure 4 The application provides a structure diagram of an air conditioner unit outdoor cavity in a rail vehicle.

[0046] Figures 5-1 to 5-5 The application provides a structure diagram of an air conditioner unit outdoor cavity in a rail vehicle.

[0047] Figure 6 The application provides a structure diagram of an air conditioner unit outdoor cavity in a rail vehicle.

[0048] The air conditioner unit 1, the outdoor cavity 2, the evaporator 3, the static pressure cavity 4, the indoor air duct 5, the passenger room 6, the first sound collecting device 7, the first sound source device 8, the second sound collecting device 9 and the second sound source device 10. DETAILED DESCRIPTION

[0049] The application will be further described in detail in combination with the drawings and specific embodiments.

[0050] The application first provides a noise over-limit sound source determination method, acquires noise through a sound acquisition device, respectively compares one or more acquired noises with standard noise, determines over-limit noise, performs octave analysis on the over-limit noise, and determines an over-limit sound source in the obtained noise frequency band.

[0051] The technical solution provided by the application is introduced by taking a rail vehicle and an air conditioning unit for the rail vehicle as examples. Figure 1 and Figure 2 As shown in the figure, the air conditioning unit 1 of the rail vehicle includes an indoor cavity and an outdoor cavity 2, the outdoor cavity 2 is arranged at the top of a passenger compartment 6, an evaporator 3 is arranged inside, and a static pressure cavity 4 is arranged at the end part. After mixing, the outdoor fresh air and the return air in the passenger compartment 6 are heat-exchanged through the evaporator 3 and filtered through a filter screen, and then flow into the static pressure cavity 4 at a high speed under the action of a ventilator. The running noise of the air conditioning unit 1 flows into the static pressure cavity 4 at the same time as the high-speed airflow after temperature change, and forms a stable airflow in the static pressure cavity 4. The stable airflow in the static pressure cavity 4 enters the passenger compartment 6 through an indoor air duct 8.

[0052] To avoid the running noise of the air conditioning unit 1 from flowing into the passenger compartment 6, an active noise reduction device is arranged in the static pressure cavity 4. In this embodiment, the active noise reduction device mainly includes a first sound source device 8 which can emit a sound source opposite in phase to the noise frequency in the static pressure cavity 4 to offset the noise frequency and achieve the purpose of eliminating noise. Before the air conditioning unit 1 is installed, the noise in the static pressure cavity 4 when the air conditioning unit 1 is running at different frequencies is respectively tested and acquired, a large amount of data is collected, data analysis is performed, the corresponding relationship between different running frequencies of the air conditioning unit 1 and the noise in the static pressure cavity 1 is determined, and the corresponding relationship is pre-stored in the controller of the air conditioning unit 1. Further, when data is acquired, the corresponding relationship between the air conditioning running frequency, the running state of the rail vehicle and the noise in the static pressure cavity 4 can also be acquired and pre-stored in the controller. After the variable frequency air conditioning system is assembled on the rail vehicle, in the running state, the outdoor fresh air and the return air in the passenger compartment 6 are mixed, heat-exchanged, filtered, and then sent to the static pressure cavity 4 at the end part of the outdoor cavity 2 by the ventilator. The wind noise and the noise generated by the air conditioning unit 1 itself running enter the static pressure cavity 4 at the same time as the high-speed airflow. The controller controls the air conditioning unit 1 to run at different frequencies according to the temperature control requirement, so as to effectively control the temperature in the passenger compartment 6. At the same time, the controller predicts the noise value in the static pressure cavity 4 according to the pre-stored corresponding relationship between the running frequency and the noise, controls the first sound source device 8 to emit a sound source opposite in phase to the noise according to the noise value, so as to achieve the purpose of eliminating noise, realize the active noise reduction in the air conditioning unit 1, make the stable and noise-free airflow output by the static pressure cavity 1 enter the passenger compartment 6 through the indoor air duct 5, and improve the comfort of the passenger compartment.

[0053] In the case that the temperature requirement of the passenger compartment 6 is unchanged and the ambient temperature is relatively stable, the air conditioning unit 1 will work at a stable operating frequency within a certain time range, but the noise in the static pressure chamber 4 can change with the running state of the rail vehicle. In order to further realize effective active noise reduction of the air conditioning unit 1, a first sound collecting device 7 is arranged in the static pressure chamber 4 to collect real-time noise values or noise data in the static pressure chamber 4 at regular intervals. The controller adjusts and controls the first sound source device 8 to emit anti-phase sound source signals in a directional manner according to the real-time noise data, so as to realize active noise reduction. The controller is provided with a timer to determine the working time T of the stable operating frequency of the air conditioning unit 1. When the working time T is greater than a predetermined time, the controller controls the first sound collecting device 7 to enter a working state, and adjusts the frequency of the anti-phase sound source emitted by the first sound source device 8 according to the real-time noise data in the static pressure chamber 4 at regular intervals as described above, so as to realize active noise reduction in the static pressure chamber 4. A passive noise reduction device can also be arranged in the static pressure chamber 4, such as laying sound-absorbing cotton on the inner wall of the static pressure chamber 4 to eliminate part of the noise.

[0054] The air flow enters the indoor air duct 5 from the static pressure chamber 4. New noise can be generated during the running process in the indoor air duct 5 and during the process of entering the passenger compartment 6 from the air outlet. In order to eliminate this part of noise, a second sound collecting device 9 is arranged in the indoor air duct 5 to collect noise data in the indoor air duct 5. Further, the second sound collecting device 9 can be installed on the bottom wall (the side wall parallel / close to the passenger compartment 6) of the indoor air duct 5, especially at the air outlet, to collect noise data at the air outlet. A second sound source device 10 is arranged in the passenger compartment 6 to emit anti-phase sound sources for the air noise at each air outlet to eliminate the air outlet noise. Correspondingly, the second sound collecting device 9 and the second sound source device 10 are connected with the controller. The controller receives the noise data collected by the second sound collecting device 9 and controls the second sound source device 10 to emit anti-phase sound sources of corresponding frequencies to eliminate the air outlet noise and realize active noise reduction outside the air conditioner. The second sound collecting device 9 can also be installed inside the passenger compartment 6, such as at each air outlet in the passenger compartment 6, to detect noise data at the air outlet. The controller controls the second sound source device 10 to emit anti-phase sound sources according to the noise data.

[0055] In the present embodiment, the first and second sound source devices adopt microphones controlled by the controller to emit sound sources of different frequencies. The emission direction of the sound source is opposite to the direction of the noise. When two sound waves of the same frequency but opposite phases meet, the sound waves balance each other and the effect of eliminating noise is realized.

[0056] It should be noted that the first / second sound collecting device and the first / second sound source device determine one or more positions with relatively large noise in the static pressure chamber 4 and the vehicle interior air duct 5 according to the big data analysis of the air conditioning system test, and determine the noise direction, so as to determine the positions of the first / second sound collecting device and the first / second sound source device, accurately measure the noise, and directionally emit the anti-phase sound source.

[0057] In the present embodiment, the first sound collecting device 7 and the first sound source device 8 are arranged in the static pressure chamber 4 at the same time, and first, the controller controls the first sound source device 8 to emit the sound source in the reverse direction of the noise according to the real-time running frequency of the air conditioning unit 1 and referring to the relationship between the running frequency and the noise in the previous big data analysis, so as to realize the active noise reduction. After the stable running frequency of the air conditioning unit 1 is unchanged, the controller adjusts the frequency of the anti-phase sound source emitted by the first sound source device 8 according to the noise data of the first collecting device 7. In actual application, if the previous large amount of test big data collection and arrangement are not performed, and the relationship between the running frequency and the noise is not pre-stored, the matching control of the first sound collecting device 7 and the first sound source device 8 can be directly used. After the air conditioning unit 1 is operated, the first sound collecting device 7 collects the noise data in the static pressure chamber 4 in real time. The controller controls the first sound source device 8 to emit the directional, anti-phase sound source with the same frequency as the noise data according to the received noise data. Or, only the relationship between the running frequency and the noise pre-stored in the controller is used to control the first sound source device 8 to emit the directional, anti-phase sound source with the same frequency as the noise data matching the running frequency. In actual application, the corresponding noise reduction device can be arranged at any position of the air conditioning unit 1 where the running noise can be generated. The sound collecting device collects the running noise generated at this position, and the sound source device emits the anti-phase sound source with the corresponding frequency to reduce the running noise generated at this position.

[0058] When the air conditioning unit 1 performs noise control, as shown in Figure 3 The sound collecting device at each frequency point (position where noise can be generated) of the air conditioning unit 1 collects the noise under all running states (each frequency point) of the air conditioning unit 1, performs octave band analysis, and extracts the sound source characteristics. At the same time, the noise at all running frequencies of each fan, compressor, air duct and other positions where the running noise can be generated is tested, octave band analysis is performed, and the sound source characteristics are extracted. The sound source frequency components and contribution of the sound collecting device are determined by comparing the sound source characteristics of the sound collecting device and the sound source characteristics of each fan and compressor. Finally, the corresponding noise characteristics of the air conditioner under each running state are obtained. The air conditioning unit 1 determines the standard noise, i.e. the noise reduction reference value, according to the noise requirement, pre-stores it in the controller, and reduces the running noise of the air conditioning unit to the standard noise or below the standard noise by the noise reduction device arranged at each position of the air conditioning unit 1. The controller can set the standard noise of the air conditioning unit 1 uniformly, or set the standard noise at each position where the running noise is generated, or set different standard noises at part of the noise positions.

[0059] The controller of the air conditioning unit 1 receives the real-time noise information collected by each sound collecting device, and controls the corresponding sound source device to emit corresponding anti-phase sound sources according to the difference between the real-time noise and the standard noise based on the pre-stored standard noise, so as to reduce the noise at this part to the standard noise or below. In this embodiment, the over-limit sound source is determined and purposefully eliminated to the standard noise or below. The system analysis and calculation of the over-limit sound source include the following steps:

[0060] S1: octave analysis is performed on the noise signal Lp collected by the sound collecting device in the car compartment to obtain Lp(f, P). In this embodiment, one-third octave analysis is performed on the noise in the range of 50Hz to 20000Hz to obtain corresponding f and P, form a noise diagram as shown in FIG. 5, and calculate the difference between adjacent frequency bands for the obtained noise frequency bands respectively: Δ 左 = |P i-1 -P i | and Δ 右 = |P i+1 -P i |, when Δ 左 or Δ 右 is greater than the limit value, it is marked as L p (f i1 , P i1 ), …, L p (f ij , P ij ), …, L p (f in , P in ), where f represents frequency, P represents amplitude; i, j, n are natural numbers;

[0061] In this embodiment, the limit value of Δ 左 or Δ 右 may be set to different values according to the need for noise reduction, so as to achieve different gear noise reduction effects, such as setting the limit value to N1, N2, N3, dividing the adjacent frequency bands into three gears, and achieving three-gear noise reduction:

[0062] When Δ 左 or Δ 右 is greater than N1, it is marked as LpH(f i1 , P i1 ), …, LpH(f ij , P ij ), …, LpH(f in , P in );

[0063] When Δ 左 or Δ 右 is greater than N2 and less than or equal to N1, it is marked as LpM(f i1 , Pi1 ),…,LpM(f ij ,P ij ),…,LpM(f in ,P in );

[0064] When Δ 左 or Δ 右 is greater than N3 and less than or equal to N2, mark LpL(f i1 ,P i1 ),…,LpL(f ij ,P ij ),…,LpL(f in ,P in );

[0065] When Δ 左 or Δ 右 is greater than 0 dB and less than or equal to N3, mark Lp(f i1 ,P i1 ),…,Lp(f ij ,P ij ),…,Lp(f in ,P in );

[0066] In this embodiment, let N1=7, N2=5, N3=3, divide the noise reduction into three grades:

[0067] When Δ 左 or Δ 右 is greater than 7 dB, mark LpH(f i1 ,P i1 ),…,LpH(f ij ,P ij ),…,LpH(f in ,P in );

[0068] When Δ 左 or Δ 右 is greater than 5 dB and less than or equal to 7 dB, mark LpM(f i1 ,P i1 ),…,LpM(f ij ,P ij ),…,LpM(f in ,P in );

[0069] When Δ 左 or Δ 右 is greater than 3 dB and less than or equal to 5 dB, mark LpL(f i1 ,P i1 ),…,LpL(f ij ,P ij),…,LpL(f in ,P in );

[0070] When Δ 左 or Δ 右 is greater than 0 dB and less than or equal to 3 dB, mark Lp(f i1 ,P i1 ),…,Lp(f ij ,P ij ),…, Lp(f in ,P in ).

[0071] Wherein f represents frequency, P represents amplitude, 50<(i,j,n)<10000.

[0072] S2, calculate:

[0073] Δ P = |MAX(P i1 ,L,P ij ,L P in )-P ij |

[0074] According to the above formula, extract all f ij of Δp>10dB in Lp7, Lp5, Lp3 respectively, and eliminate in the first step mark respectively. Obtain the final Lp of high, medium and low three grades (F0, P). Wherein F0 is the frequency of the over-limit sound source.

[0075] The total sound pressure level of the noise is collected by the sound collection device, and the noise is analyzed by one octave analysis, and the frequency band of the noise can be obtained, wherein the Y axis can be the sound pressure value corresponding to the different frequencies of the noise frequency band, and the total sound pressure of the noise can be calculated by one-third octave calculation. In the frequency band diagram, the prominent frequency band will make the total sound pressure level larger, therefore, in order to reduce the noise, the frequency band causing the total sound pressure level of the noise to become larger needs to be found and determined, and the frequency band can be determined as the over-limit sound source frequency, and the over-limit sound source frequency is targeted for noise reduction processing, and the overall sound pressure level is reduced by reducing the sound pressure value of the frequency band corresponding to the over-limit sound source frequency, so that the effect of noise reduction is achieved. In the embodiment, the running noises of five fans are collected respectively, and the collected noises are analyzed by one-third octave analysis, and five noise frequency band diagrams as shown in FIG. 5 are obtained. Figures 5-1 to 5-5 The total sound pressure levels of the noises corresponding to each diagram are obtained by calculating the frequency band of each noise frequency band diagram, and are 56.55 dB(A), 58.03 dB(A), 57.49 dB(A), 58.79 dB(A) and 58.71 dB(A) respectively, all of which exceed the standard value of 55 dB(A). According to the theoretical requirements, the running noises of each fan need to be processed for noise reduction.

[0076] As shown in Figure 5, Figure 5-1 , the Y axis is the sound pressure value of the noise frequency band of the acquisition band. The connection line of each frequency band forms a relatively smooth curve. The connection line between most frequency bands and the left and right frequency bands is relatively smooth. As mentioned above, the range of each difference value can be determined by calculating Δleft and / or Δright between each frequency band, (7, ∝), (5, 7), (3, 5), (0, 3), and then calculating Δp, and extracting f with Δp>10dB. ij After being eliminated, only 4 excessive sound source frequencies are finally obtained. As shown in the figure, the four frequency bands marked by numbers are marked as excessive sound sources. Noise reduction can be performed on these four frequency bands to reduce the noise (amplitude). For example, the sound pressure of the excessive sound source can be directly reduced to Δ left or Δ right of the original frequency band, so that the Δ left or Δ right calculated for this frequency band after reduction and the adjacent frequency band are within the allowable range, so that the frequency band corresponding to this excessive sound source is close to the frequency band adjacent to its left or right, and no abrupt frequency is formed. Figure 5-3 The situation is similar.

[0077] right Figures 5-2 to 5-5 The noise shown is processed in the same way, and the Δ 左 and / or Δ 右 , determine the interval range of each difference, (7, ∝), (5, 7), (3, 5), (0, 3), mark them respectively, calculate Δp, and extract f with Δp>10dB ij After elimination, the frequency of the excessive sound source is finally obtained. The frequency bands marked with numbers in the figure are marked as excessive sound sources, and targeted noise reduction processing is performed. The anti-phase sound source is emitted through the sound source device to reduce the sound pressure value of the excessive sound source, thereby reducing the noise.

[0078] It should be noted that, in this embodiment, noise is reduced by emitting anti-phase sound sources, but not all noise is reduced to zero. Instead, by determining the excessive sound sources, the abrupt frequency band is reduced to an amplitude close to that of other frequency bands, so that the operating noise is relatively smooth without sharp sounds.

[0079] The two-step method for identifying excessive noise source frequencies first identifies frequencies with large differences between adjacent frequency bands, effectively impacting sound quality. Secondly, by comparing the amplitude differences between the corresponding harmonics, the larger frequency bands are identified, effectively selecting the frequencies with the greatest impact on noise levels. The excessive noise source frequencies identified in this way are those with the greatest impact on sound quality and sound pressure. Using these excessive frequencies for noise reduction ensures both accurate noise reduction and improved sound quality.

[0080] In addition, the difference between adjacent frequency bands is divided into three levels: high, medium and low, that is, the impact of the sound quality from the out-of-limit sound source is also divided into three levels, which can be used to determine the target out-of-limit frequency of intelligent noise reduction and sound quality improvement at the same time.

[0081] In the method as described above, when the air conditioning unit 1 is installed on the rail car, the noise reduction control method is also applicable to the intelligent noise reduction control in the entire car, in addition to the noise reduction devices arranged by the air conditioning unit 1, corresponding noise reduction devices can also be arranged in the car to reduce the noise in the car, to realize the real-time monitoring of the noise in the car (including the operation noise of the air conditioning unit 1 in the car) and automatically start the active noise reduction device (the sound source device capable of emitting the anti-phase sound source) when the noise signal collected exceeds the standard noise in the car, to realize the intelligent noise reduction. Figure 4 As shown in the figure, the air conditioning unit 1 obtains the output signal Lp of the sound collection device in the car through the controller, and the control system compares the real-time collected noise value Lp with the required value L of the noise in the room (the standard noise), if Lp ≤ L required value, then return, and re-detect the noise in the car at an interval of 10s to feed back the value. If Lp > L required value, the logic derivation enters the next step, detects the duration of Lp exceeding the required value, when the duration > 10s, enters the next step logic, analyzes the noise characteristics collected in the car (uses the method shown in the figure), and further determines the frequency F0 of the over-limit sound source; when the duration is less than or equal to 10s, the number of continuous detection is counted, if the number of continuous times is greater than 10 times, the logic derivation enters the next step, if the number of continuous times is not greater than 10 times, then return to re-detect the noise in the car to feed back the value. After analyzing the noise characteristics collected in the car and determining the frequency F0 of the over-limit sound source, the active noise reduction devices in the air conditioner and in the car are selectively started or simultaneously started according to the frequency components of the over-limit sound source obtained by the analysis. In actual application, the interval of the noise detection in the car and the number of continuous detection can be set according to the accuracy of the noise control requirement. Figure 3

[0082] In the embodiments provided by the present application, while the real-time monitoring of the noise in the car and the intelligent noise reduction processing can be realized, the state abnormal alarm signal can also be fed back when the continuous detection of the noise exceeds the limit number of times. The air conditioning unit 1 obtains the output signal Lp of the sound collection device in the car through the internal controller, and the control system compares the real-time collected noise value Lp with the required value L of the noise in the room, if Lp ≤ L required value, then return, and re-detect the noise in the car to feed back the value. If Lp > L required value, then enter the next step to start the intelligent noise reduction module.

[0083] The continuous detection time is set to confirm whether the noise duration t in the car is continuously over-limit, if t = 90 minutes, it is judged that the noise duration t in the car exceeds the required value 90 minutes, then enter the next step, if the continuous number of times is 5 or more, the air conditioning control system sends an alarm signal to the air conditioning operation and maintenance system.

[0084] ​Herein, taking the air conditioner of the rail vehicle as an example, the intelligent noise reduction control method of the air conditioner is introduced, and in actual application, the air conditioner unit 1 can be applied to various environments requiring temperature regulation, such as workshops, office buildings, etc., and cannot be considered as a limitation of the present application due to the foregoing. Similarly, the noise exceeding source, the frequency of the noise exceeding source, and the noise reduction method provided by the present application can also be applied to various technical fields that can generate noise and require noise reduction. The method described in the foregoing is built into the control device of the noise reduction device, and the space controlled by the device and requiring noise reduction control is controlled for noise reduction. The noise reduction device includes one or more sound collection devices that can collect noise data at different positions and sound source devices. According to the method described in the foregoing, noise reduction control, noise exceeding alarm notification, and operation and maintenance system rectification operations are performed.

[0085] In summary, the noise exceeding source determination method, air conditioner, vehicle, noise control method, and noise reduction device provided by the present application have the following beneficial effects compared with the prior art:

[0086] 1. When the in-vehicle noise exceeds the standard, the intelligent noise reduction measure is started, the target is hit, the vehicle ride comfort is improved, and the noise reduction cost is reduced.

[0087] 2. The air conditioner output noise anomaly can realize early warning and remind repair;

[0088] 3. When the in-vehicle noise continuously appears abnormally, early warning and repair can be realized;

[0089] 4. In the context of the increasingly intelligent air conditioner, regular inspection of air conditioner noise can be effectively reduced or avoided, a more comfortable riding environment can be provided, manual inspection can be saved, manpower cost can be saved, safety and reliability can be improved.

[0090] As described above, in combination with the given scheme content, similar technical solutions can be derived. Any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present application still belongs to the scope of the present application.

Claims

1. A method of determining a noise infrasound source, characterized in that: The noise is collected by the sound collecting device, and one or more collected noises are compared with the standard noise respectively to determine the over-limit noise, and the over-limit noise is analyzed by octave band to determine the over-limit sound source in the obtained noise frequency band The following steps are adopted when analyzing the obtained over-limit noise to determine the over-limit sound source, S1, octave analysis is performed on the over-limit noise signal Lp collected by the sound collection device to obtain f and P corresponding to Lp(f, P) of the noise, the obtained noise frequency band is calculated respectively to obtain the difference value of adjacent frequency bands, wherein Δ 左 =|P i-1 -P i | and Δ 右 =|P i+1 -P i |, when Δ 左 or Δ 右 is greater than the limit value, it is marked as L p (f i1 ,P i1 ), …, L p (f ij ,P ij ), …, L p (f in ,P in ), wherein f represents frequency and P represents amplitude; i, j, n are natural numbers; S2, compute Δ P = |MAX(P i1 ,…,P ij ,…P in )-P ij |, when Δp is greater than a predetermined value, eliminate, get the final super limit sound source Lp(F0, P), wherein F0 is the frequency of the super limit sound source.

2. The noise source determination method of claim 1, wherein :Δ 左 or Δ 右 The limits of Δ are multiple and are each labeled.

3. The noise source determination method of claim 2, wherein: The limit value includes N1, N2 and N3, and the adjacent frequency bands are differentiated into three grades, when When Δ 左 or Δ 右 is greater than N1, mark LpH(f i1 , P i1 ), …, LpH(f ij , P ij ), …, LpH(f in , P in ); when Δ 左 or Δ 右 is greater than N2 and less than or equal to N1, mark LpM(f i1 , P i1 ), …, LpM(f ij , P ij ), …, LpM(f in , P in ); When Δ 左 or Δ 右 is greater than N3 and less than or equal to N2, the label LpL(f i1 , P i1 ), …, LpL(f ij , P ij ), …, LpL(f in , P in ) is assigned. When Δ 左 or Δ 右 is greater than 0 dB and less than or equal to N3, mark Lp(f i1 , P i1 ), …, Lp(f ij , P ij ), …, Lp(f in , P in ); Through step S2, the three-grade over-limit sound source and the corresponding sound source frequency Lp(F0, P) are obtained.

4. The noise source localization method of claim 1, wherein: The ultra-limit noise is analyzed in the third octave of 50Hz-20000Hz, the frequency and amplitude of the noise are obtained, 50<(i,j,n)<20000.

5. An air conditioner characterized by comprising: A plurality of sound collecting devices are arranged in the air conditioner, and the running noise at each point is collected, the noise over-limit sound source is determined by the method of any one of claims 1 to 4, and the sound source device capable of emitting the anti-phase sound source of the noise is arranged at the collection point to reduce the over-limit sound source below the standard noise.

6. A vehicle characterized by: The vehicle includes an air conditioning unit, a plurality of sound collecting devices for collecting noise data at different points are arranged in the vehicle cabin and the air conditioning unit, and corresponding sound source devices are arranged, the sound source devices determine the over-limit sound source in the collected noise data and emit the anti-phase sound source to reduce the noise according to the method of any one of claims 1 to 4.

7. A method of noise control, characterized by: A plurality of sound collecting devices are arranged in the space where noise reduction control is required, and a sound source device is arranged corresponding to each sound collecting device, the sound collecting devices collect real-time running noise signals Lp at different positions respectively, and transmit the signals to a control device, compare the signals with the corresponding standard noise L stored in advance respectively, and record the noise signal Lp data and comparison results at each collection point, wherein, If Lp≤L, the noise collection and comparison are performed again after a predetermined interval time; If Lp>L, the noise is marked as over-limit noise, if the over-limit noise duration is greater than T, the over-limit sound source and the frequency F0 of the over-limit sound source are determined by analyzing the over-limit noise according to the method of any one of claims 1 to 5; If Lp>L, the noise is marked as over-limit noise, if the over-limit noise duration is less than or equal to T, and the continuous number of times is greater than n, the over-limit sound source and the frequency F0 of the over-limit sound source are determined by analyzing the over-limit noise according to the method of any one of claims 1 to 4; If Lp>L, the noise is marked as over-limit noise, if the over-limit noise duration is less than or equal to T, and the continuous number of times is less than or equal to n, the noise collection and comparison are repeated. The noise signals Lp at each collection point are compared respectively, and the over-limit sound source frequency F0 of each noise over-limit collection point is obtained, and the control device controls the corresponding sound source device to emit the anti-phase sound source of the over-limit sound source according to the specific over-limit sound source frequency of each collection point, thereby reducing the noise at the position.

8. A noise control method as claimed in claim 7, characterized in that: The control device is provided with an alarm device, which confirms the duration of the real-time noise Lp>L at each collection point, and sends an alarm signal to the operation and maintenance system if it is judged that the noise duration t at a certain collection point exceeds the limit value.

9. A noise control method as claimed in claim 8, characterized in that: The control device confirms the duration of the real-time noise Lp>L at each collection point, and records the over-limit number of times, and the alarm device sends an alarm signal to the operation and maintenance system when the over-limit number of times is greater than a predetermined value.

10. A noise reduction device, characterized by: The noise reduction device comprises a sound collecting device and a sound source device. The noise reduction device confirms the super-limit sound source according to the method of any one of claims 1 to 4. The sound source device emits a reverse-phase sound source according to the frequency of the confirmed super-limit sound source, thereby reducing noise.

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