50 results about "Acoustic pollution" patented technology

The invention relates to a design method for a linear active-disturbance-rejection controller based on a prediction tracking differentiator, and the method comprises the following steps: a, designingthe prediction tracking differentiator, and performing the filtering of an obtained state signal through the prediction tracking differentiator to obtain a filter value; b, obtaining an extension state of the system through an extension state observer based on the filter value; c, correcting a PD control law through the extension state to obtain the linear active-disturbance-rejection controller.The method provided by the invention can inhibit the impact on the closed-loop characteristics of a system from the noise pollution, can effectively inhibit the phase delay phenomenon caused by the filtering, solves a problem of noise pollution amplification caused by a high-gain observer, and improves the robustness of a controller. The method improves the robustness of the active-disturbance-rejection controller to the high-frequency noise, and has the engineering practicality.

The invention relates to a superposed assembly type structure subway station and an assembly construction method thereof. At present, when the station construction is carried out, a large number of formworks are needed, the field operation amount is large, and the construction period is long; environmental water pollution, noise pollution and air pollution can also be caused by the cast-in-place wetting operation, the superposed assembly type structure subway station comprises a top plate (1), a middle plate (2), a bottom plate (3), a heat exhaust air duct (5) and a side wall (4), and is characterized in that a construction joint from the bottom plate to the bottom of a negative second layer is of a cast-in-place reinforced concrete structure, and an exposed grouting sleeve is pre-buried at the construction joint and is connected with an upper side wall stress steel bar; the side wall inner skin is a precast block with truss bars and serves as an inner side formwork at the same time, the bottom of the side wall inner skin is inserted into the grouting sleeve, the stress steel bars are connected by pouring efficient grouting materials, a cast-in-place belt is arranged on the construction joint, side wall cavity concrete is poured, and a side wall overlapping structure is formed. The method thereof is applied to the field of subway construction.

The invention discloses a supporting noise reduction system for a combustion gas turbine mobile power station, and relates to the technical field of prevention of noise pollution. The system comprisesa sound insulation box body used for mounting a combustion gas turbine, wherein the bottom of the sound insulation body is fixedly mounted on a suspending body frame through a sound attenuation system underframe, and wheels are mounted at the bottom of the suspending body frame; an inlet gas sound attenuation system is connected to one end of the sound insulation box body, and an intake air soundattenuation system is arranged above the inlet gas sound attenuation system and communicates with a gas inlet of the sound insulation box body; and a first-stage exhaust sound attenuation system is arranged at the top of the other end of the sound insulation box body, a second-stage exhaust sound attenuation system is mounted at the top of the first-stage exhaust sound attenuation system, and thefirst-stage exhaust sound attenuation communicates with an exhaust port of the sound insulation box body. According to the supporting noise reduction system for the combustion gas turbine mobile power station, noise produced by the combustion gas turbine during working is reduced, and the working environment is protected.

The invention relates to a rail transit steel-concrete composite beam with a sound insulation function, and relates to the technical field of bridge construction; the rail transit steel-concrete composite beam comprises a steel-concrete bridge deck slab, two steel main beams and a plurality of transverse supports; the two steel main beams are arranged on the two sides of the steel-concrete bridge deck slab respectively in the cross bridge direction, and the bottom ends of the steel main beams are connected with the steel-concrete bridge deck slab; and the plurality of transverse supports are arranged at intervals in the longitudinal bridge direction, the two ends of each transverse support are connected to the top ends of the two steel main beams respectively, and the transverse supports, the steel-concrete bridge deck slab and the steel main beams jointly define a sound insulation cavity. According to the steel-concrete composite beam, the mechanical property advantages of the two materials are exerted, the structural bearing capacity and flexural rigidity are enhanced, the problem that a bridge deck slab in a hogging moment area cracks is solved, when a vehicle travels in the sound insulation cavity, propagation of wheel track noise can be effectively isolated, and train operation sound pollution is reduced. And meanwhile, the steel structure can be subjected to factory prefabrication, the construction quality is guaranteed, and the construction efficiency is correspondingly improved.

The invention provides a low-noise transformer oil tank. The oil tank comprises an oil tank inner wall, an oil tank outer wall and a noise reduction interlayer arranged between the oil tank inner wall and the oil tank outer wall, wherein the noise reduction interlayer comprises an interlayer structure used for transmitting noise vibration energy and mass blocks located on the two sides of the interlayer structure, and the mass block is used for converting and consuming noise energy so as to reduce noise pollution. The oil tank can reduce outward propagation of sound waves, reduces noise transmitted by the tank wall of the oil-immersed transformer, is low in cost, does not affect the overall appearance shape of the tank wall, and can be used for a long time without maintenance.

The invention provides a mobile terminal high-precision distance and speed estimation method and system based on sound. The method comprises the following steps of: acquiring a composite hyperbolic frequency modulation signal; performing time delay estimation on hyperbolic frequency-modulated signals of two different frequency bands of the composite hyperbolic frequency-modulated signal at the same time to respectively obtain time delay estimation values of the hyperbolic frequency-modulated signals of the two different frequency bands, resolving to obtain a Doppler factor and a time delay estimation value of the composite hyperbolic frequency-modulated signal, and calculating a distance estimation value and a speed estimation value according to the Doppler factor and the time delay estimation value of the composite hyperbolic frequency modulation signal. The prior information of a sound source signal is used as a reference signal, and the distance and speed information can be obtained at the same time only through two times of generalized cross-correlation or two matched filters, so that spectrum leakage is effectively inhibited, sound pollution is avoided, the signal-to-noise ratio of the signal is effectively ensured, the estimation accuracy and calculation complexity can meet the indoor positioning system requirements for the intelligent mobile terminal, and the mobile terminal high-precision distance and speed estimation method and system have good application and popularization values.

The invention provides a concrete dam deformation combined forecasting model construction method based on ARIMA and PSO-ELM, and aims at the characteristics of high nonlinearity and uncertainty causedby mutual influence of multiple factors in the dam deformation process, irregular chaotic characteristics caused by complex noise pollution and the like. An ensemble empirical mode (EEMD) is used tocarry out adaptive analysis and processing on a residual sequence of a displacement hybrid model, a particle swarm optimization (PSO) algorithm is used to optimize ELM and select an optimal input weight matrix and hidden layer deviation, and a PSOELM model is constructed to optimize a nonlinear high-frequency induction signal of the PSOELM model; meanwhile, fitting prediction is carried out on a low-frequency trend signal by means of an autoregressive integral moving average model (ARIMA), and a multi-scale deformation optimization combination forecasting model is established. Compared with atraditional model, the built model is higher in prediction precision, noise interference in the monitoring sequence can be overcome, the multi-scale characteristic of the dam monitoring sequence can be reflected, and the dam monitoring data time sequence can be analyzed and judged more clearly and comprehensively.

The invention discloses a noise reduction type cooling tower additionally provided with air inlet and outlet silencers. The cooling tower comprises a shell, a filling structure, a spraying structure and an air suction structure. The shell is provided with an air inlet and an air outlet. The air inlet communicates with the air outlet. The air suction structure, the spraying structure and the filling structure are contained and fixed in the shell. The spraying structure is fixed to the filling structure so that spraying can sufficiently cover the filling structure. Air is sucked in from the air inlet through the air suction structure, cooled through the filling structure and exhausted by the air outlet. The noise reduction type cooling tower additionally provided with the air inlet and outlet silencers further comprises a first silencing structure and a second silencing structure. The first silencing structure is fixed to the air inlet, and the second silencing structure is fixed to the air outlet so as to reduce noise. The first silencing structure and the second silencing structure are arranged on the air inlet and the air outlet to reduce the overall noise, noise pollution is reduced, and the working environment is improved.

A method for managing knock in a cylinder of an internal combustion engine, in a system including at least one acoustic sensor and a processor, in order to take into account acoustic pollution resulting from a noise, the method including: forming and digitizing the signals of the acoustic sensor, applying a bandpass filter to obtain a filtered noise, determining an adjustable gain-correction function using a gain-correction curve and, depending on the angular position of the end of injection, the point on the gain-correction curve to be used to convert the filtered noise into a corrected knock score, comparing a corrected knock score thus obtained to a knock decision threshold, to correct the timing advance, the gain-correction curve being defined by a calibration value and four angular points obtained by calculation based on the start and end positions of a knock-observation window and on a known characteristic of the noise.

The invention discloses an intelligent control system power generation device, which comprises a power generator, a handle is fixedly installed on the outer surface of the top of the power generator,an oil conveying pipeline is fixedly installed on the outer surface of the top of the power generator, a rotary knob cover is arranged above the oil conveying pipeline, and an external thread is formed in the outer wall of the top end of the oil conveying pipeline, an internal thread is formed in the inner wall of the rotary knob cover, the rotary knob cover is in threaded connection with the oilconveying pipeline, a power transmission line is fixedly connected to one side of the power generator, and a plug is fixedly installed at the end, away from the power generator, of the power transmission line. The intelligent control system power generation device is provided with silencing plates, heat conduction plates, wing-shaped bolts and heat dissipation pipes, has excellent silencing and noise reduction capacity, reduces sound pollution brought by the power generator, has excellent heat dissipation capacity, can also facilitate maintenance of the internal structure of the power generator, and brings better use prospects.

The invention discloses an inner container with a noise reduction structure and a dish-washing machine. The inner container comprises a box body and further comprises a noise reduction device and a sound transmission component, wherein a plurality of through holes are formed in the side wall of the box body, the noise reduction device is arranged on the outer wall of the box body, the sound transmission component is arranged between the box body and the noise reduction device and covers the plurality of through holes, and the noise reduction device corresponds to the through holes so as to enable noise in the box body to be transmitted outwards after sequentially passing through the through holes, the sound transmission component and the noise reduction device. The structure is simple, thenoise problem of the inner container can be effectively solved, and then noise pollution is effectively reduced.

The invention provides a preparation method of a material composition for effectively relieving noise pollution. The preparation method is characterized by comprising the following steps: a) ultrahigh molecular weight polyethylene powder, a poring agent and a sound insulation medium are mixed to obtain a mixture; the weight ratio of the ultrahigh molecular weight polyethylene powder to the poring agent and to the sound insulation medium is 100-300: 50-100: 100-150; and the sound insulation medium is one or several of modified zeolite, activated attapulgite, modified diatomite, coke powder, pumice powder and montmorillonite powder; and b) the mixture obtained in the step a) is pressed, sintered and cooled in a mold; the pressing pressure is 0.4-1 MPa; the sintering temperature is 200-250 DEG C; the sintering time is 60-120 min; and the cooling temperature is 40-60 DEG C. The prepared material composition can preferably relieve the harm of the noise pollution to people.

The invention belongs to the field of marine engineering vibration and noise, and provides an array truncated conical shell bubble curtain underwater piling noise reduction device, which includes a truncated conical shell, inner and outer ring pipes containing air holes, inner and outer standpipes, and an external air compressor , the truncated conical shell is connected with the inner and outer ring pipes through hooks, the inner and outer ring pipes are fixedly connected with the inner and outer vertical pipes through threaded four-way pipes, and the external air compressor is located in the whole The top of the structure is connected to the uppermost ends of the inner and outer vertical pipes through flexible pipes. The device of the present invention guides the propagation of sound waves obliquely through the conical shell in the low frequency band, effectively directional radiates sound waves with longer wavelengths, utilizes the irregularity of sea surface waves, and increases the sound wave propagation path to transmit and consume sound energy to the sea surface of the far sea; In the mid-to-high frequency band, the double-layer bubble curtain produced by the air holes along the inner and outer sides of the conical shell performs resonance absorption and diffuse scattering, effectively reducing noise pollution.

The invention discloses a silencing device, and belongs to the technical field of silencers. The invention aims to process and reduce noise generated by an engine and reduce noise pollution. According to the technical scheme, the silencing device comprises an outer shell, and a first partition plate, a second partition plate, a third partition plate, a fourth partition plate and a fifth partition plate are sequentially arranged between one end and the other end in the outer shell to divide the interior of the outer shell into a first silencing chamber, a second silencing chamber, a third silencing chamber, a fourth silencing chamber, a fifth silencing chamber and a sixth silencing chamber; an air inlet is formed in the outer shell of the third anechoic chamber, and an air outlet is formed in the outer shell of the sixth anechoic chamber.

The invention relates to a shock absorption and noise reduction mechanism of a water feeding pump, and belongs to the technical field of water pumps, the shock absorption and noise reduction mechanism comprises a shell arranged on a pump body in a sleeving mode, a through hole allowing a water receiving pipe to penetrate out is formed in the shell, and a sound insulation assembly used for stopping sound waves generated by the pump body from diffusing is arranged in the shell; a base is arranged below the pump body, and a damping assembly for buffering and damping the pump body is arranged between the pump body and the base; the shell is installed on the base. The method has the effect of reducing sound pollution caused by the water pump.

The invention discloses a vibration and noise reduction compaction table, and belongs to the technical field of environmental governance. The vibration and noise reduction compaction table comprises a compaction platform used for bearing a compaction device and a material to be vibrated, and further comprises a two-stage vibration reduction assembly, a sound insulation cover assembly and a counterweight table. One end of the counterweight table is fixedly connected with the compaction platform, the other end of the counterweight table is fixedly connected with the two-stage vibration reduction assembly, and the compaction platform, the two-stage vibration reduction assembly and the counterweight table are all wrapped by the sound insulation cover assembly. When the compaction platform is stressed to vibrate, the two-stage vibration reduction assembly can buffer acting force transmitted by the compaction platform through the counterweight table. The sound insulation cover assembly can obstruct noise generated by stress vibration of the compaction platform so as to realize vibration and noise reduction. According to the vibration and noise reduction compaction table, a noise reduction mechanism composed of the two-stage vibration reduction assembly, the sound insulation cover assembly and the counterweight table is adopted, the compaction table can carry out vibration and noise reduction reliably, noise pollution is reduced, and the noise influence range is widened.

The invention relates to the technical field of express sorting auxiliary equipment, in particular to anti-stacking auxiliary equipment for express sorting in electronic commerce. The anti-stacking auxiliary equipment comprises an equipment main body, a fixed plate is fixedly connected in the equipment main body, and an electromagnet is fixedly connected to the top surface in the fixed plate; a compression spring is fixedly connected to the position, located on the left side of the fixing plate, in the equipment body; and a transmission rod is fixedly connected to the lower end of the compression spring, a rotating disc is rotatably connected to the interior of the equipment body, and a positioning sliding rail is fixedly connected to the interior of the rotating disc. According to the anti-stacking auxiliary equipment, an express box is moved to the middle of a conveyor belt through a moving plate, so that contact with a protective fence due to inertia influence is avoided, blockage is avoided, and the rapid box conveying efficiency can be well improved; and the protective liquid in the plastic air cushion is extruded and discharged so that an equipment rotating shaft can be well lubricated and protected, and therefore sound pollution of equipment to the environment can be well avoided.

The earphone structure provided by the invention relates to the technical field of earphones. The earphone structure comprises a loudspeaker, comprising a sounding diaphragm and a sound outlet, wherein the sounding diaphragm is used for converting an electric signal into sound and outputting the electric signal through the sound outlet; a pipe, wherein one end of the pipe is arranged on one side of the horn having a sound outlet, and the other end extends in a direction away from the sound outlet to transmit sound output from the sound outlet to an outer space. As a result of that above arrangement, the problem that acoustic wave reflection is prone to occur in the cavity due to the cavity between the pipe and the sound outlet in the prior art can be avoided, and the problem that acousticwave reflection cause acoustic pollution can be improved.