A radar human sensing and active noise reduction system applied to a BOG compressor

Abstract

The utility model provides a radar human sensing and initiative noise reduction system applied to BOG compressor, specifically related to compressor noise reduction technical field. The system includes main control MCU, monitoring mechanism, a plurality of noise detection mechanism and a plurality of executive structure, the monitoring mechanism includes a plurality of radar human sensing module, is used to monitor whether there is the inspection staff around the compressor and positions its, the noise detection mechanism includes noise reduction MCU and sound collection microphone, is used to detect the environmental noise and the communication voice of the inspection staff, realizes audio spectrum analysis calculation, the executive mechanism includes power amplifier module and power noise reduction loudspeaker, is used to amplify audio signal, reduces environmental noise interference, exports reverse audio signal. The utility model discloses through setting up radar human sensing module monitoring whether there is personnel in the working environment and completes personnel position positioning, combines noise reduction MCU and can be targeted to the environmental noise and cancels out while not affecting the voice communication between the staff.

Description

Technical Field

[0001] This utility model relates to the field of compressor noise reduction technology, specifically to a radar human detection and active noise reduction system applied to BOG compressors. Background Technology

[0002] LNG receiving terminal industrial sites are subject to various industrial noises, among which the operating noise of BOG compressors is a very common one.

[0003] Sound propagation has three main elements: sound source, propagation path, and receiver. Noise is also a type of sound and possesses these three elements as well. The high noise levels of BOG compressors in industrial settings have a serious impact on the physical and mental health of workers and inspectors. Noise reduction can be achieved through the following three methods: Method one is to reduce the noise source. BOG compressors use quieter motors and more advanced control methods to reduce the noise source. Method two is to isolate the transmission path, such as wrapping the compressor with sound-absorbing cotton and installing it further away from workers. The first two methods are the most traditional passive noise reduction methods, which can alleviate the noise problem to some extent, but the effect is not satisfactory. Method three is to use noise-canceling headphones for noise reduction, but this method starts from the receiver. Noise-canceling headphones only reduce noise for an individual and cannot produce a wide range of effects.

[0004] To address the aforementioned problems, this invention proposes a radar human detection and active noise reduction system for BOG compressors. Utility Model Content

[0005] To overcome the shortcomings of the prior art, this utility model provides a radar human detection and active noise reduction system applied to BOG compressors, the specific technical solution of which is as follows: A radar-based human detection and active noise reduction system for BOG compressors includes a main control MCU, a monitoring mechanism, several noise detection mechanisms, and several execution structures. The monitoring mechanism includes several radar human detection modules for monitoring whether there are inspection personnel around the compressor and locating their positions. The noise detection mechanisms include a noise reduction MCU and a sound acquisition microphone for detecting ambient noise and the communication voices of the inspection personnel, and performing audio spectrum analysis and calculation. The execution mechanisms include a power amplifier module and a power noise-reducing speaker for amplifying audio signals, reducing ambient noise interference, and outputting an inverse audio signal to superimpose and cancel out the noise. Each radar human detection module corresponds to one noise detection mechanism and one execution structure, and is considered as a unit noise reduction group.

[0006] Preferably, the main control MCU is a TMS32F28377 digital signal processor.

[0007] Preferably, the noise reduction MCU is an ATH8806 digital signal processing chip.

[0008] Preferably, the noise reduction MCU uses a short-time Fourier transform module to perform spectrum analysis calculations.

[0009] Preferably, the noise reduction MCU performs noise reduction processing on sounds in specific frequency bands below 300Hz and above 1kHz.

[0010] Preferably, the power amplifier module is an ST-8866 power amplifier with a power of 2000W.

[0011] Preferably, the monitoring mechanism, several noise detection mechanisms, and several execution structures are all electrically connected to the main control MCU.

[0012] More preferably, the radar human sensing module, sound acquisition microphone and power noise reduction speaker in each noise reduction unit are installed together to form an assembly; several assemblies are distributed at equal intervals around the compressor along the walking path of the inspection staff and the distance between them and the compressor casing is ≤30m.

[0013] Even more preferably, the resolution frequencies of the sound acquisition microphone and the power noise-reducing speaker are both 20Hz to 20kHz.

[0014] More preferably, the power of the power noise-reducing speaker is greater than or equal to the noise power of the BOG compressor.

[0015] The beneficial effects of this utility model are: 1. This utility model can achieve automatic local noise reduction, which only reduces noise in areas where people are present, thus preventing noise interference caused by noise reduction in unrelated areas; 2. This utility model can achieve energy saving and noise reduction, and the corresponding noise reduction module can be turned off in areas where no one is active; 3. This utility model can achieve selective noise reduction, and adopts voice preservation noise reduction logic, which can reduce ambient noise only while preserving the voice communication between staff. Attached Figure Description

[0016] The accompanying drawings constituting this utility model are provided to further understand this application and do not constitute an undue limitation on this application.

[0017] Figure 1 This is a schematic diagram illustrating the working principle of this utility model; Figure 2 This is the program flowchart of the main control MCU of this utility model; Figure 3 A spectral analysis diagram of the complete audio; Figure 4 The spectrum diagram is for full noise reduction. Detailed Implementation

[0018] The specific implementation of a radar human detection and active noise reduction system for BOG compressors provided by this utility model will be further described with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 The aforementioned radar-based human detection and active noise reduction system for BOG compressors includes a main control MCU, a monitoring mechanism, several noise detection mechanisms, and several execution structures. The monitoring mechanism includes several radar-based human detection modules for detecting the presence of inspection personnel around the compressor and locating their positions. The noise detection mechanisms include a noise-reducing MCU and a sound acquisition microphone for detecting ambient noise and the communication voices of inspection personnel, performing audio spectrum analysis and calculation. The execution mechanisms include a power amplifier module and a power noise-reducing speaker for amplifying audio signals, reducing ambient noise interference, and outputting a reverse audio signal to superimpose and cancel out noise. It is worth noting that each radar-based human detection module corresponds to one noise detection mechanism and one execution structure, and is considered a unit noise reduction group.

[0020] Preferably, the main control MCU is a TMS32F28377 digital signal processor (DSP).

[0021] Preferably, the noise reduction MCU uses the ATH8806 digital signal processing chip (echo cancellation and ambient noise suppression), and utilizes a short-time Fourier transform module to perform spectrum analysis calculations. It is worth noting that the noise frequency generated by the BOG compressor is mainly distributed below 300Hz, while human voice frequencies are mainly distributed between 300Hz and 1kHz. To achieve ambient noise reduction while preserving the communication between inspection personnel, the noise reduction spectrum needs to bypass the human voice frequency band. That is, the noise reduction MCU can be set to perform noise reduction processing only on specific frequency bands below 300Hz and above 1kHz to achieve a targeted noise reduction effect.

[0022] Preferably, the power amplifier module is an ST-8866 power amplifier with a power of 2000W, which effectively amplifies the signal and ensures the stable output of the power noise-reducing speaker.

[0023] More preferably, the radar human sensing module, sound acquisition microphone and power noise reduction speaker in each noise reduction unit are installed together to form an assembly; several assemblies are distributed at equal intervals around the compressor along the walking path of the inspection personnel and the distance between them and the compressor casing is ≤30m, so as to ensure that the compressor working environment is monitored without blind spots (the noise outside the 30m range is basically attenuated to an acceptable range and no noise reduction is required).

[0024] Even more preferably, the resolution frequencies of the sound acquisition microphone and the power noise-reducing speaker are both 20Hz to 20kHz.

[0025] More preferably, since there is a certain linear relationship between the noise and power of the compressor, the power of the noise-reducing speaker needs to be greater than or equal to the noise power of the BOG compressor to avoid the problem of weakened noise reduction effect due to insufficient power.

[0026] It is worth noting that the monitoring mechanism, several noise detection mechanisms, and several execution structures are all controlled by the main control MCU.

[0027] like Figure 2 As shown, during operation, all radar human detection modules process the running status and continuously monitor whether inspection personnel are present in the compressor's working area. If no personnel are present, the noise detection mechanism and execution structure corresponding to that radar human detection module will not be activated. If personnel are detected, the noise detection mechanism and execution structure corresponding to that radar human detection module will be activated. The radar human detection module locates the position of the inspection personnel, and simultaneously, the sound acquisition microphone collects sound (including ambient noise, noise generated by personnel movements, and voice communication between personnel) and transmits the audio signal to the noise reduction MCU. The noise reduction MCU uses short-time Fourier transform to complete the audio spectrum analysis and calculation of all sound segments, such as... Figure 3 As shown, noise is categorized into two types: directional noise and ambient noise. Based on the audio analysis diagram, noise reduction is applied to specific frequency bands below 300Hz and above 1kHz. The power amplifier module amplifies the signal and utilizes a power noise-canceling speaker to stably output an inverse audio signal of the same magnitude as the noise-canceling frequency. This signal is superimposed on and cancels out the noise, while preserving the communication between inspection personnel. Alternatively, it can be set to full noise reduction without frequency band distinction, achieving a noise reduction effect as shown... Figure 4 As shown, while this setting provides good noise reduction, it may also cancel out communication sounds.

[0028] It is worth noting that the number of noise monitoring and execution mechanisms corresponds to the number of radar human detection modules, enabling independent noise reduction for each monitored area. No noise reduction is required in areas without personnel. The radar human detection module transmits unmanned information to the main control MCU, and the MCU terminates the power supply to the sound acquisition microphone and power noise reduction speaker, thereby achieving energy-saving and noise reduction effects.

[0029] In this utility model, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are merely used to facilitate the description of the structural relationships of the various components or elements of this utility model and do not specifically refer to any part or element of this utility model; they should not be construed as limiting this utility model. Terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and they should not be construed as limiting this utility model.

[0030] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A radar-based human detection and active noise reduction system applied to a BOG compressor, characterized in that, It includes a main control MCU, a monitoring mechanism, several noise detection mechanisms, and several execution structures; The monitoring mechanism includes several radar human detection modules, used to monitor whether there are inspection personnel around the compressor and locate the location of the inspection personnel. The noise detection mechanism includes a noise-reducing MCU and a sound acquisition microphone, which are used to detect the current ambient noise and the communication voices of the inspection staff, and to realize audio spectrum analysis and calculation. The actuator includes a power amplifier module and a power noise-canceling speaker, which is used to amplify the audio signal, reduce environmental noise interference, and output an inverse audio signal to superimpose and cancel out the noise. Each radar human-sensing module corresponds to a noise detection mechanism and an execution structure, and is regarded as a unit noise reduction group.

2. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 1, characterized in that, The main control MCU is a TMS32F28377 digital signal processor.

3. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 1, characterized in that, The noise reduction MCU uses the ATH8806 digital signal processing chip.

4. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 3, characterized in that, The noise reduction MCU uses a short-time Fourier transform module to perform spectrum analysis calculations.

5. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 4, characterized in that, The noise reduction MCU performs noise reduction processing on sounds in specific frequency bands below 300Hz and above 1kHz.

6. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 1, characterized in that, The power amplifier module is an ST-8866 model with a power of 2000W.

7. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 1, characterized in that, The monitoring mechanism, several noise detection mechanisms, and several execution structures are all electrically connected to the main control MCU.

8. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 1, characterized in that, The radar human sensing module, sound acquisition microphone and power noise-canceling speaker in each noise reduction unit are installed together to form a combination unit; Several assemblies are evenly distributed around the compressor along the walking path of the inspection staff, with a distance of ≤30m between them and the compressor casing.

9. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 1, characterized in that, The resolution of both the sound acquisition microphone and the power noise-canceling speaker is 20Hz to 20kHz.

10. The radar human detection and active noise reduction system applied to a BOG compressor according to claim 9, characterized in that, The power of the noise-reducing loudspeaker is greater than or equal to the noise power of the BOG compressor.

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