20results about How to "Reduce high frequency noise" patented technology

The invention relates to an ultrasonic fluid metering precision improving method and related equipment, and the method comprises the steps: exciting a first ultrasonic transducer through an excitation wave sequence, enabling a second ultrasonic transducer to work, obtaining a received digital signal corresponding to the excitation wave sequence, and calculating the signal-to-noise ratio of the received digital signal; wherein the excitation wave sequence is a combination of a main wave and a self-damping wave, and the signal-to-noise ratio is a ratio of a peak-to-peak value of a receiving signal area to a peak-to-peak value of a noise area; judging whether the signal-to-noise ratio is greater than a signal-to-noise ratio threshold value or not, if not, adjusting the occupation time of the high and low levels of the self-damping waves, and executing the excitation work again according to the adjusted excitation wave sequence until the actual signal-to-noise ratio is greater than the signal-to-noise ratio threshold value; and determining the corresponding excitation wave sequence when the actual signal-to-noise ratio is greater than the signal-to-noise ratio threshold as a target excitation wave sequence, and exciting the ultrasonic transducer to work according to the target excitation wave sequence so as to execute metering operation. According to the method, the measurement precision is remarkably improved while the hardware cost is not increased.

This utility model relates to the field of pipeline technology, specifically to a compressor venting and noise reduction pipeline and its noise reduction system. The compressor venting and noise reduction pipeline includes: an exhaust pipeline, a bend downstream of the exhaust pipeline, a branch pipeline downstream of the bend, an output pipeline downstream of the branch pipeline, and a silencer downstream of the output pipeline. The silencer includes a spiral flow guiding device. This utility model reduces the velocity of the medium flow by using the bend, branch pipeline, and silencer, consuming part of the kinetic energy of the medium flow, thereby reducing the noise generated by the medium colliding with the pipe wall during discharge and reducing the safety risks to on-site personnel.

The utility model provides a holding circuit and a charging device. The holding circuit comprises a power failure holding module. The power failure holding module comprises a first capacitor and a first diode; the first end of the first capacitor is connected with the anode of the first diode, and the second end of the first capacitor is connected with the cathode of the first diode; the first end of the first capacitor is also used for being connected with a low potential output end of a power supply module, and the second end of the first capacitor is also used for being connected with a high potential output end of the power supply module; wherein a low potential output end and a high potential output end of the power supply module are respectively connected with a load. According to the holding circuit, the diode and the capacitor are connected in parallel to form a quick discharge circuit, so that the discharge efficiency is improved, and the stability and the integrity of data in a load are improved.

The utility model discloses a wired earphone with an external microphone module, which is characterized in that a microphone unit is detachably connected with a mounting seat, and a blowout prevention protective sleeve is sleeved outside the microphone unit, so that the direct impact of airflow on the microphone unit can be reduced, the'spouting sound 'generated by breathing airflow can be effectively filtered, and compared with the traditional wired earphone, the wired earphone has the advantages of simple structure and convenience in use. The wired earphone provided by the utility model can keep human voice details while attenuating high-frequency noise, and is especially suitable for outdoor communication scenes.

The utility model belongs to the technical field of brushless motors, in particular to a plastic shell motor structure, which comprises a rotor, a stator and a plastic shell integrally formed by injection molding, the radial section of the plastic shell is W-shaped, and the plastic shell comprises an outer shell part and an isolation part which completely isolate the rotor from the stator. An opening for assembling the rotor and the stator is formed in one side, opposite to the isolation part, of the shell part; when the stator and the rotor are fixed by the plastic shell, the stator and the rotor are separated, due to the rigid design of the plastic shell, accurate positioning of the stator and the rotor can be ensured, uniform air gaps between the stator and the rotor are ensured, and vibration, noise and efficiency reduction caused by eccentricity are avoided; the plastic shell can enhance the insulation grade and can meet the double insulation design, and the power can be higher under the same condition; even if more enameled wires are wound on the stator to increase the power of the motor, the stator still meets the safety requirement of the electrical clearance, so that the motor can safely operate under higher power.

The invention discloses an effective signal extraction method and system based on CVAE, and relates to the field of digital signal processing, and the method comprises the specific steps: constructing a conditional variation auto-encoder which comprises an encoder, a re-parameterization module and a decoder; constructing a training data set based on the observation data set and the corresponding conditional variable set; training the conditional variation auto-encoder by using the training data set, and performing parameter optimization on the conditional variation auto-encoder by using a loss function based on physical consistency constraint; the loss function based on the physical consistency constraint comprises a reconstruction error item, a KL divergence loss item and a physical constraint loss item; acquiring to-be-processed data and corresponding conditional variables; and inputting to-be-processed data and conditional variables into the trained conditional variation auto-encoder to obtain effective signals. According to the method, physical consistency constraint is introduced through the conditional variation auto-encoder, high-frequency noise and pseudo-frequency components are effectively weakened, and a reconstructed signal is closer to a real signal.

The application discloses a kind of analysis and prediction methods of high-frequency noise of pod propeller, comprising the following steps: S1, obtain the flow field original data and corresponding high-frequency noise monitoring data under the working state of pod propeller, and pre-process;S2, based on the separated vortex model, construct flow field-noise coupling analysis framework, set the time step and calculation frequency matched with actual working condition, the present application relates to ship propeller noise analysis and prediction technical field.The analysis and prediction method of high-frequency noise of the pod propeller, by constructing flow field-noise coupling analysis framework, the pre-processed flow field data are processed, the vortex structure characteristics of flow field can be captured, and based on the correlation mechanism of vortex structure and noise generation, the contribution of each vortex unit to high-frequency noise is accurately calculated, the vortex unit of dominant noise source is screened, and the dynamic positioning of high-frequency noise source is realized in combination with its space-time position information, which helps to understand the root of noise generation.

This utility model discloses a sound absorption and noise reduction structure for a vacuum cleaner, including an airflow channel pipe. One end of the airflow channel pipe is snapped into a vacuum cleaner connector. Dust chamber shell one and dust chamber shell two are respectively attached to both sides of the airflow channel pipe. The mating surfaces of dust chamber shell one and dust chamber shell two are snapped into each other, and a handle ring is snapped into the outer side of the dust chamber shell one near the vacuum cleaner connector end, and a limit ring is snapped into the outer side of the dust chamber shell one away from the handle ring end. A dust chamber shell cover is snapped into the top of dust chamber shell one and dust chamber shell two. Heat dissipation holes are opened on the bottom side of each dust chamber shell one and dust chamber shell two, and a motor assembly is fixedly connected inside the corresponding heat dissipation holes. Through the integrated design of airflow channel optimization, vibration isolation, composite noise reduction and efficient heat dissipation, the acoustic performance of the vacuum cleaner is improved while ensuring heat dissipation efficiency and structural reliability, achieving a comprehensive technical effect of low noise and high stability.

An expansion valve comprises a valve seat and a valve needle, the valve seat is provided with a valve cavity and a valve port channel, and the valve needle comprises a tip part and a columnar part; the valve port channel comprises a first valve port channel and a second valve port channel, and the second valve port channel is far away from the columnar part relative to the first valve port channel in the height direction of the expansion valve; a first opening is formed in the end, close to the columnar part, of the first valve port channel. A second opening is formed in the end, close to the first valve port channel, of the second valve port channel. A plane perpendicular to the height direction of the expansion valve is defined as a first projection plane, the orthographic projection of the inner wall corresponding to the first opening on the first projection plane is a first projection, the orthographic projection of the inner wall corresponding to the second opening on the first projection plane is a second projection, and at least part of the second projection is located in the first projection; the area enclosed by the first projection is larger than the area enclosed by the second projection.

This application provides a single-sided detection system and vehicle. The single-sided detection system includes a voltage divider circuit, an amplifier circuit, an isolation circuit, an output circuit, and a controller. The voltage divider circuit divides the voltage of the high-voltage DC bus to obtain a first output voltage. The amplifier circuit is connected to the voltage divider circuit. The isolation circuit is connected to both the amplifier circuit and the voltage divider circuit. The output circuit includes a first operational amplifier and a first resistor. The inverting input terminal of the first operational amplifier and one end of the first resistor are connected to the fifth terminal of the isolation circuit, and the non-inverting input terminal of the first operational amplifier is connected to the sixth terminal of the isolation circuit. The first operational amplifier generates a second output voltage. The controller determines the voltage of the high-voltage DC bus based on the second output voltage. This single-sided detection system can isolate and monitor the voltage of the high-voltage DC bus, promptly detect voltage anomalies, and, with the isolation circuit, provides a high level of overall system safety.

The utility model belongs to noise reduction device technical field especially has a packing noise reduction device with air outlet buffer structure, including electromagnetic valve and frame board, the outside of electromagnetic valve is equipped with frame board, the inside of frame board has established screw groove and storage groove in proper order, storage groove and connecting plate sliding butt joint, the upper side of connecting plate is connected with the one end of bolt through bearing. This packing noise reduction device with air outlet buffer structure, when electromagnetic valve starts, gas passes the air outlet hole of electromagnetic valve and enters the inside of connecting pipe, the elasticity of connecting pipe can absorb and weaken the vibration between airflow and pipe wall, and the vibration and the propagation of sound that isolation layer can reduce the vibration of connecting pipe, after the air diffusion and flow in the open hole box, can effectively reduce the impact sound and high frequency noise of airflow, make packing noise reduction device in long -term operation, especially in the system of frequent switch can stably carry out noise reduction to electromagnetic valve.

This application discloses an effective signal extraction method and system based on CVAE, relating to the field of digital signal processing. The specific steps are as follows: constructing a conditional variational autoencoder (CVAE), which includes an encoder, a reparameterization module, and a decoder; constructing a training dataset based on an observation dataset and a corresponding set of conditional variables; training the CVAE using the training dataset and optimizing its parameters using a loss function based on physical consistency constraints; the loss function based on physical consistency constraints includes a reconstruction error term, a KL divergence loss term, and a physical constraint loss term; obtaining the data to be processed and the corresponding conditional variables; and inputting the data to be processed and the conditional variables into the trained CVAE to obtain the effective signal. This application introduces physical consistency constraints through a CVAE, effectively reducing high-frequency noise and pseudo-frequency components, making the reconstructed signal closer to the real signal.

The utility model relates to the technical field of air conditioners, in particular to an axial flow fan which comprises an installation disc, blades, a first reinforcing part and a second reinforcing part. The blades are arranged on the peripheral wall of the mounting disc; the first reinforcing part is arranged on the suction surface of the blade and is close to the front edge side of the blade; the first reinforcing part extends to the blade top of the blade from the blade root of the blade; the second reinforcing part is arranged on the suction surface of the blade and is close to the tail edge side of the blade; the second reinforcing part extends to the blade top of the blade from the blade root of the blade; the structural strength of the blades is improved, and therefore the strength requirement of the axial flow fan is met.

The present application relates to the technical field of safety protection tools, and is especially a pumped storage power station active noise reduction safety protection device and a noise reduction method, comprising a wearable shell and an active noise reduction mechanism, the inner wall of the wearable shell is provided with sound-absorbing cotton, and an inner lining frame is fixedly arranged on the inner side of the sound-absorbing cotton, the active noise reduction mechanism comprises a sound pickup end, a loudspeaker end and an active noise reduction unit, and the inner walls on the left and right sides of the wearable shell are both provided with jacks. The present application combines passive noise reduction with active noise reduction, first uses the selective noise reduction characteristics of sound-absorbing cotton to reduce high-frequency noise, uses polyester fiber sound-absorbing cotton for sound insulation in the wearable shell to reduce high-frequency noise, and then embeds a low-pass filter in the active noise reduction protection device to filter high-frequency noise again, ensures that the ANC master control module focuses more on the processing of low-frequency noise, and guarantees the low-frequency noise reduction effect.

The utility model relates to the technical field of stamping dies, in particular to a noise reduction type automobile stamping die and a control method.The noise reduction type automobile stamping die comprises a base, a die table is fixedly installed above the base, a die groove is formed in the upper end of the die table, a channel is formed in the lower end of the die table, and first air cylinders symmetrically distributed along the base are arranged in the channel; the lower end of the first air cylinder is fixed to the surface of the base through a screw, and a first piston rod for stretching is arranged in the first air cylinder. According to the scheme, wide-frequency-band noise control is achieved through the design of the five-layer composite sound insulation cover, the core innovation is that the synergistic effect of the array type rubber sound insulation columns and layered materials is achieved, the hollow structures of the sound insulation columns are combined with the rubber damping characteristic, 500-2000 Hz high-frequency noise can be attenuated in a targeted mode, and the impedance gradient design of the polyurethane foam reinforcing layer and the sound insulation cotton layer can achieve the purpose of noise reduction. And the die adopts a two-way limiting mechanism and a double-cylinder driving design, so that the accurate matching of a die head and a die groove is ensured, and the repeated positioning accuracy of stamping is high.

This application provides a headphone sound transmission device and a headphone. The headphone sound transmission device includes a sound transmitting element and a sound receiving element; the sound transmitting element has a first sound transmission channel and a second sound transmission channel that are interconnected, forming a sound transmission angle between the first and second sound transmission channels. The first sound transmission channel is connected to the inlet of the sound transmitting element, and the second sound transmission channel is connected to the outlet of the sound transmitting element. The sound receiving element is connected to the sound transmitting element and has a sound receiving port that is connected to the outlet of the sound transmitting element. When sound enters the sound transmitting element, it passes through the first and second sound transmission channels in sequence. The first and second sound transmission channels intersect each other, which attenuates and blocks high-frequency noise signals in the sound signal, thus reducing the high-frequency noise in the incoming sound and effectively improving the noise reduction capability against external noise.

The utility model relates to a kind of exhaust muffler of power supply vehicle and power supply vehicle, first turnover cover and second turnover cover are respectively set in the two sides of exhaust port, the bottom of first turnover cover and second turnover cover is respectively hinged with the carriage of power supply vehicle;Two first flow guides are respectively located in the inside of the other two sides of exhaust port, two first flow guides are respectively connected with the left and right sides of first turnover cover;Two second flow guides are respectively located in the inside of the other two sides of exhaust port, two second flow guides are respectively connected with the left and right sides of second turnover cover, two second flow guides are respectively located in the inside of two first flow guides;First turnover mechanism is used to turn over first turnover cover and two first flow guides up and down, to open or close exhaust port;Second turnover mechanism is used to turn over second turnover cover and two second flow guides up and down, to open or close exhaust port.When working, form the exhaust passage that is closed in all directions upward, reduce noise, reduce the influence to surrounding environment.

This utility model discloses an electromagnetic interference-resistant end cover for an automotive lock motor, comprising an end cover body, a thermal protector, a varistor, an inductor, a first carbon brush, a second carbon brush, a positive terminal, and a negative terminal. The first carbon brush is connected to one end of the thermal protector via a first conductive terminal, and the other end of the thermal protector is connected to the positive terminal. The second carbon brush is connected to one end of the inductor via a second conductive terminal, and the other end of the inductor is connected to the negative terminal. A first capacitor is connected between the first and second conductive terminals. The thermal protector of this utility model can automatically cut off the current when the motor is overloaded or the temperature is too high, preventing motor damage. The inductor can suppress electromagnetic interference, smoothing the current during frequent motor starts and stops and high-speed operation, thereby attenuating electromagnetic emission and radiation interference. The first and second capacitors filter out high-frequency noise and reduce current fluctuations, thereby effectively attenuating impedance-conducted interference. The overall structural layout is reasonable, effectively improving the electromagnetic compatibility and stability of the motor.

This invention provides a method for generating lace texture images based on an ADM (Adaptive Demographic Model) and dynamic denoising filtering model. This model combines a learnable Gaussian blur layer with a high-pass filtering technique. The Gaussian blur layer adaptively adjusts the blur intensity based on the input image, reducing high-frequency noise in the lace texture image. The high-pass filtering technique enhances key areas such as the outline and edges of the main pattern in the image, thereby highlighting the main texture features. Adding this module to the downsampling layer of the ADM network improves the overly smooth appearance of the lace texture images generated by the original model and enhances the image's texture depth.

The utility model relates to the technical field of air conditioners, in particular to an indoor unit and an air conditioning system, and aims to solve the problem that an existing indoor unit easily generates abnormal sound due to thermal expansion and cold contraction during startup and shutdown. In order to achieve the purpose, the indoor unit comprises a plurality of air conditioner parts which are connected with one another, and the air conditioner parts are provided with matching surfaces so as to be matched with other air conditioner parts; one of two adjacent matching surfaces is provided with a first micro bulge, and the other one is provided with a second micro bulge; the first micro bulges comprise a plurality of convex strips and / or a plurality of convex points which are sequentially arranged on the matching surface; the second micro-protrusions comprise a plurality of protruding points arranged on the matching face. In the thermal expansion and cold contraction process, the first micro protrusions and the second micro protrusions can transversely expand and contract, the expansion amount and the contraction amount of the air conditioner components are reduced, the displacement amount between the adjacent air conditioner components is reduced, and noise caused by thermal expansion and cold contraction is reduced; and the stress concentration phenomenon of a geometric edge area can be reduced, and contact slippage between air conditioner components is improved.