68 results about "Air coupled" patented technology

The invention provides an ultrasonic detection method and system for inverting residual stress by using sound wave phase velocity, and belongs to the field of air coupling ultrasonic guided wave detection. The method is based on an air coupling ultrasonic guided wave sound field propagation finite element model, and guides optimization design of air coupling ultrasonic transducer parameters. The air coupling ultrasonic guided wave detection technology is adopted for conducting non-contact excitation and receiving of guided wave signals on the composite material component with the preset stress through the stretcher. And calculating the phase velocity of the air-coupled ultrasonic guided wave in the composite material component based on a geometric positioning and time difference cooperative gradual difference method. And calibrating the phase velocity in the target composite material and preset stress to obtain a corresponding relational expression, performing phase velocity detection on a composite material component with unknown stress based on a calibration result of the target composite material, and performing inversion to obtain composite material construction residual stress. By adopting the method and the system, the residual stress detection of the composite material component is realized.

The invention provides an airflow drying and surface modification technology for lemon fibers, relates to the technical field of lemon surface processing, and realizes the whole process optimization of lemon fiber production through ultrasonic-microwave synergistic extraction, pulse type ultrasonic-hot air coupling airflow drying, low-temperature plasma surface modification and an intelligent control system based on Q-learning. The pectin yield is increased by about 20% through ultrasonic-microwave synergistic extraction, the extraction time is shortened by 50%, flow drying is assisted by double-frequency ultrasonic waves and magnetized water mist, the drying time is shortened by 50%, the energy consumption is reduced by 20%, the fiber softness is improved by 15%, the fiber is endowed with 99% antibacterial rate and excellent hydrophilicity through low-temperature plasma modification, chemical reagents are not needed, and environmental pollution is reduced. The intelligent control system converts waste liquid into ethanol and lactic acid through real-time data optimization and closed-loop resource utilization, zero waste discharge is achieved, the ethanol yield is increased by 12%, the additional value of lemon peel byproducts is remarkably increased, and the method is suitable for the fields of food and materials and conforms to the green chemistry concept.

An air-coupled ultrasonic scanning platform for an air-coupled ultrasonic non-contact metrology of battery electrodes that maps the local variation in density and thickness, and detect defects during electrode casting and drying, includes: piezocomposite air-coupled transducers (Ultran) at 0.5 to 1 MHz that provide sufficient air coupling to enable sound waves to travel through air from a transmitting transducer, through the thin film electrode coated on metal current collector, and then into the receiving transducer. Non-contact, air-coupled ultrasound may be used as a technique for evaluating battery electrode films. An analytical model was derived from fundamental acoustic wave propagation principles to determine acoustic density. Voltage gain or acoustic density maps of electrode films revealed features that are not visually apparent, attributed to mass gradients.

The invention discloses a shaft defect rapid detection method. The method comprises the steps of detection area planning and signal acquisition, signal processing and defect judgment reference determination, space mapping and defect judgment and the like. The shaft defect rapid detection method is based on an air coupling impact echo method and is a nondestructive detection method aiming at shaft detection defects, and rapid data acquisition can be realized through response of an air coupling sensor acquisition structure to an impact echo signal; the intact position and the position with cracks or defects can be clearly distinguished under the condition that the main frequency intervals are overlapped by analyzing the energy ratio of the spectrogram; by drawing the defect cloud picture, the defect information can be visually displayed, and the difficulty of manual judgment can be reduced. According to the shaft defect rapid detection method, the engineering application problems of low detection efficiency, high main frequency misjudgment rate and the like can be solved on the premise of realizing non-contact detection, and a theoretical basis and data support can be provided for performing efficient, high-precision and high-adaptability nondestructive detection evaluation on the shaft.

The invention discloses a lithium battery full life cycle health state monitoring method, belongs to the technical field of lithium ion battery detection, and aims to identify pore defects and dynamic bubble behaviors in a battery in real time. According to the method, broadband ultrasonic waves are emitted through an air coupling multi-probe array, and back scattering signals caused by bubbles and uneven structures in a battery in the charging and discharging process are collected. And in combination with a porous medium acoustic theory, extracting time domain and frequency domain characteristic parameters related to the bubble form and distribution, and inputting the time domain and frequency domain characteristic parameters into a preset bubble state-signal response model. On the basis, the evolution state of the internal gas production defect of the battery is judged, so that effective support is provided for fault early warning and safe operation of the lithium ion battery. The method has the remarkable advantages of simplicity and convenience in operation, high real-time performance, high accuracy and the like, and can be widely applied to online detection and quality control of a battery production line.

The utility model discloses a kind of non-contact optical coherence elastic imaging endoscope devices, comprising: non-contact ultrasonic excitation and optical detection integrated probe and high-speed sweep frequency laser, the integrated probe includes air-coupled ultrasonic transducer, collimating optical fiber, off-axis parabolic mirror and polymer resin packaging shell, air-coupled ultrasonic transducer diameter is not greater than 2.5 mm, center frequency is not less than 250 kHz, collimating optical fiber is single-mode fiber and emission end integrated collimator is used to produce collimating beam, off-axis parabolic mirror focal length is greater than 7 mm, the polymer resin packaging shell is used to integrally package integrated probe, the polymer resin packaging shell is designed using 3D printing, and it is windowed at the exit end of the off-axis parabolic mirror;The scanning speed of this high-speed sweep frequency laser is 100 kHz, center wavelength 1310 nm, bandwidth 100 nm, synchronous output trigger clock and sampling clock.

The invention provides a terahertz MIMO array imaging device and an air coupling calibration method thereof, and relates to the technical field of terahertz imaging and microwave measurement, and the device comprises a vector network analyzer which is used for transmitting a step frequency continuous wave signal and receiving an echo signal; the radio frequency interfaces of the terahertz frequency doubling transmitting modules are connected to the radio frequency port of the vector network analyzer through radio frequency cables; a plurality of terahertz frequency multiplication receiving modules, wherein intermediate frequency interfaces and local oscillator interfaces of the terahertz frequency multiplication receiving modules are respectively connected to an intermediate frequency input port and a local oscillator output port of the vector network analyzer through cables; the at least one calibration module is fixed on the column of the array frame, is positioned obliquely below the transmitting module and the receiving module, and points to the transmitting module and the receiving module obliquely and upwards; the transmitting module and the receiving module are arranged into a linear MIMO array.

The application discloses a kind of vehicle-mounted tunnel lining defect detection device and method, wherein the method comprises: tunnel lining interior fine detection mechanism is with mechanical arm swing mode and vertical lifting mode, respectively with the ground coupling type geological radar antenna carried, extend to tunnel lining surface, and the spacing between ground coupling type geological radar antenna and tunnel lining surface is controlled in preset distance interval;Tunnel lining interior rapid screening device is with mechanical electric drive servo dynamic adjustment air-coupled geological radar antenna carried;Detection data evaluation system carries out the calculation of tunnel lining quality index, and obtains tunnel lining defect detection result;The tunnel lining quality index reflects the degree of tunnel lining defect.The application can improve the efficiency and accuracy of vehicle-mounted tunnel lining defect detection.

This invention discloses a device and its application method for food quality testing based on air-coupled ultrasound technology, relating to the field of fruit and vegetable quality testing technology. The device includes a base plate with two opposing detection mechanisms slidably mounted on it along the Y-axis, and a placement platform between the mechanisms. The placement platform is mounted on a horizontal moving mechanism and moves up and down along the Z-axis with the vertical moving mechanism, enabling sample adjustment in the X and Z-axis directions. The detection mechanisms hold the ultrasonic transducer using a four-jaw chuck. Utilizing the independent adjustment characteristics of the four jaws of the chuck, combined with the A-scan waveform fed back from the ultrasonic pulse transceiver, precise coaxial alignment of the acoustic centers of the transmitting and receiving probes is achieved. This invention effectively solves the problems of large mechanical vibration, difficulty in aligning the acoustic center of the probe, and difficulty in performing repeatable grid scanning in existing devices, providing a stable and reliable hardware platform for texture evaluation and internal structure imaging of fruits, vegetables, and other foods.

The invention provides a Lamb wave benchmark-free damage imaging method based on adaptive clustering and semantic weighting, and belongs to the technical field of air coupling ultrasonic detection.The Lamb wave benchmark-free damage imaging method comprises the steps that a full-path response signal is collected through orthogonal scanning, a wavelet low-frequency approximation coefficient and a normalized symmetric difference factor are extracted to construct a joint feature vector; and performing unsupervised division of'health-damage 'states on a scanning path by adopting DBSCAN clustering. And semantic tags obtained by clustering are further used as adaptive weights to be embedded into the improved RAPID probability imaging model, and dynamic construction of artifact path suppression and soft reference is realized. In a layering defect detection experiment of the carbon fiber reinforced composite material, compared with a traditional RAPID method, the average size measurement error is reduced by 50.5% under the condition that an independent health reference is completely not needed, the measurement precision of 40 * 20 * 0.05 mm defects in the X / Y direction is improved by 81.7%, the measurement precision of 40 * 20 * 0.05 mm defects in the Y / X direction is improved by 65.5%, and meanwhile 92.3% of boundary artifacts are effectively restrained.

The invention discloses a leakage detection method for a composite material component with a cavity based on an air coupling ultrasonic technology, and the method comprises the steps: scanning a to-be-detected component in an atmospheric environment through employing the air coupling ultrasonic technology, so as to obtain a first ultrasonic scanning image; placing the to-be-tested component in an atmosphere filled with inert high-density gas; taking out the to-be-detected component from the atmosphere, and scanning the to-be-detected component again in the atmospheric environment by using the air coupling ultrasonic technology so as to acquire a second ultrasonic scanning image; and comparing the second ultrasonic scanning image with the first ultrasonic scanning image to check whether the second ultrasonic scanning image presents an additional high-attenuation area or not. According to the invention, defect detection and leakage detection of the composite material component with the cavity can be realized in a completely lossless manner in a dry environment, and the leakage detection efficiency is remarkably improved.

The application provides a cotton seed quality online detection method, device, system and storage medium, comprising: in the case that the quality category of the to-be-detected cotton seed is not the first quality category, acquiring an air-coupled ultrasonic signal for detecting the quality of the to-be-detected cotton seed; generating a target image based on the air-coupled ultrasonic signal; inputting the target image into a trained cotton seed quality detection model to output a target quality category of the to-be-detected cotton seed; the trained cotton seed quality detection model is obtained after training according to a target image sample; the target image sample is obtained by acquiring a target image of a cotton seed sample of a second quality category and a target image of a cotton seed sample with an intact epidermis; the epidermis damage degree of the cotton seed of the first quality category is greater than that of the cotton seed of the second quality category. The application can effectively detect slightly damaged cotton seeds, effectively screen intact cotton seeds without damage, and greatly improve the efficiency of cotton seed online sorting.

The application provides a transmitting air-coupled dual-frequency piezoelectric ultrasonic transducer, wherein a low-frequency piezoelectric vibrator is arranged in front, and a high-frequency piezoelectric vibrator is arranged in back, and the ultrasonic transducer specifically comprises a high-frequency matching layer, a low-frequency flexible circuit layer, an insulating layer and a high-frequency piezoelectric vibrator arranged in sequence, the low-frequency piezoelectric vibrator is of a multi-element structure, a cavity is etched on the lower surface of the high-frequency matching layer, the low-frequency piezoelectric vibrator is embedded in the cavity on the lower surface of the high-frequency matching layer and is attached to the low-frequency flexible circuit layer, the insulating layer is used for isolating the electrical signals between the high-frequency piezoelectric vibrator and the low-frequency piezoelectric vibrator, and the low-frequency flexible circuit layer is used for exciting the low-frequency piezoelectric vibrator. The application solves the problem that the longitudinal resolution and the sound energy transmission efficiency cannot be considered simultaneously in the field of air-coupled ultrasonic technology. The application belongs to the field of ultrasonic nondestructive testing technology.

The invention provides a multi-parameter performance detection system and method for a polyphenyl ether foaming material, and the method comprises the steps: carrying out the time domain demodulation of terahertz time domain waveform data of the polyphenyl ether foaming material, extracting a first characteristic parameter representing the near-surface defect of the material, carrying out the frequency domain recognition of an ultrasonic transmission signal of the polyphenyl ether foaming material, and carrying out the detection of the near-surface defect of the material; extracting a second characteristic parameter representing the internal defect and the thickness change of the material; performing feature fusion on the first feature parameter and the second feature parameter by using sensor confidence coefficients of a terahertz time-domain spectrum sensor and an air coupling ultrasonic sensor to obtain a defect feature vector of the polyphenyl ether foaming material; and using the defect feature vectors to distinguish defect types and position defect positions, comparing the defect types with a pre-stored acceptance standard threshold, and generating a disposal decision instruction of the current polyphenyl ether foaming material. Based on the scheme, the adaptive fusion of the multi-modal sensing data and the defect probability confidence can be realized, so that the judgment precision of online nondestructive testing of the polyphenyl ether foaming material can be improved.

The invention relates to an ultrasonic array sensor (100) for detecting distances between a vehicle and objects in the surroundings of the vehicle, comprising at least one diaphragm component (110) having a vibrating diaphragm (111) and a cavity (113) in the interior of the diaphragm component (110); and at least two transducer elements (130), wherein each transducer element (130) is mechanically coupled to a diaphragm region (112), wherein the ultrasonic array sensor (100) has a support structure (120) which is arranged in the cavity (113) of the diaphragm component (110) and contacts a contact region of the diaphragm (111) on the inner side (118), as a result of which the diaphragm (111) is divided into at least two separate vibrating diaphragm regions (112), wherein the support structure (120) creates a natural frequency distance Δf eig between the different vibration modes of the diaphragm (111) of the ultrasonic array sensor (100) of less than or equal to 10% with respect to the operating frequency op of the ultrasonic array sensor (100).

An ultrasonic automatic flaw detection device belongs to the technical field of ultrasonic flaw detection, and aims to solve the problems that surface interference is mistakenly judged as internal cracks or inclusions and damage is caused by direct contact between a probe and a large shaft. The ultrasonic automatic flaw detection device comprises a rack, a driving part is mounted in the rack, and a moving plate is arranged on the surface of the driving part; a high-frequency alternating magnetic field is excited through the electromagnetic coil, obstacles such as rust layer protrusions and weld beading on the surface of the large shaft can be penetrated, ultrasonic waves are directly generated in a metal base body, an ultrasonic probe does not need to make contact with the large shaft, on one hand, the ultrasonic probe is not prone to damage, and on the other hand, the ultrasonic probe is not prone to damage. On the one hand, false signals generated by barrier reflection of a traditional contact type probe are avoided, the misjudgment rate is reduced, on the other hand, ultrasonic reflected waves can be received through air coupling without a coupling agent, energy loss caused by non-uniform smearing of the coupling agent is reduced, and interference of surface barriers on detection is eliminated.

The invention relates to an air coupling ultrasonic detection system based on multiple optical encoders and a working method thereof. The system comprises a main body device, a coding device, a detection device and a control device, the coding device and the detection device are respectively connected with the main body device and are respectively connected with the control device through a wireless network; the encoding device comprises a plurality of optical encoder groups and is used for monitoring the translation and rotation movement of the system so as to obtain the position information of the ultrasonic guided wave signal; each optical encoder group consists of a displacement optical encoder and a distance optical encoder; the detection device comprises an air coupling ultrasonic probe used for collecting ultrasonic guided wave signals. Compared with the prior art, the method has the advantages of high reliability, accurate detection result and the like.

The utility model relates to a kind of arch top unmanned detection devices of power generation diversion tunnel inclined shaft section lining structure, and it is related to tunnel detection technical field, it includes traction mechanism, walking mechanism, adjusting mechanism and detection mechanism.Traction mechanism is connected with walking mechanism;Adjusting mechanism includes first telescopic unit and second telescopic unit, first telescopic unit is installed in walking mechanism and is connected with second telescopic unit;Detection mechanism includes detection platform, air coupled radar and ranging sensor, detection platform is installed in second telescopic unit, and air coupled radar and ranging sensor are all installed in detection platform;Second telescopic unit is connected with detection platform;First telescopic unit is used to drive second telescopic unit and detection platform reciprocating linear motion in first direction relative to walking mechanism;Second telescopic unit is used to drive detection platform to lift in second direction relative to walking mechanism;First direction and second direction have included angle.It is flexible to control, and stability is high, safety is high, and detection result is accurate and reliable.

An automatic ultrasonic flaw detection device, belonging to the field of ultrasonic flaw detection technology, aims to solve the problems of misjudging surface interference as internal cracks or inclusions and damage caused by direct contact between the probe and the shaft. The invention includes a frame, a drive component installed inside the frame, a movable plate on the surface of the drive component, a fixed cylinder fixedly installed inside the movable plate, and a fixed column slidably connected inside the fixed cylinder. This invention uses an electromagnetic coil to excite a high-frequency alternating magnetic field, which can penetrate obstacles such as rust protrusions and weld beads on the surface of the shaft, directly generating ultrasonic waves in the metal substrate. This eliminates the need for the ultrasonic probe to contact the shaft. On the one hand, it avoids false signals generated by reflections from obstacles in traditional contact probes, reducing the false judgment rate. On the other hand, it can receive ultrasonic reflected waves through air coupling without the need for a coupling agent, reducing energy loss caused by uneven application of the coupling agent and eliminating interference from surface obstacles.

A luminaire is provided, having an enclosure and a chamber air coupled to the enclosure. The enclosure includes luminaire components that emit a light beam, has an opening, and is otherwise sealed. The chamber includes a drying agent, two openings, and is otherwise sealed from the external air. One opening of the chamber is coupled by a sealed air coupling to the opening of the enclosure. The other opening of the chamber is completely covered by a membrane that allows air to pass through the material while reducing the passage of water droplets in the air. The enclosure may include sensors that measure air pressure, air humidity, and / or air temperature of the enclosure. The luminaire may include a control system configured to collect data from the sensors and to send information related to the collected data to a user of the luminaire via a communication channel.

The present invention relates to the technical field of air-coupled ultrasonic sensors, and specifically to a simulation design method for optimizing air-coupled ultrasonic sensors. To address the high preparation cost and time-consuming nature of conventional optimization methods for air-coupled ultrasonic sensors, a new simulation design method for optimizing air-coupled ultrasonic sensors is provided, comprising the following steps: 1) establishing Leach equivalent circuit models of different piezoelectric composite materials and performing simulation optimization to obtain the optimal piezoelectric composite material; 2) establishing a lossless transmission line model of a first matching layer based on the equivalent circuit model corresponding to the optimal piezoelectric composite material and performing simulation analysis to obtain the optimal first matching layer; and 3) establishing a lossless transmission line model of a second matching layer based on the circuit model corresponding to the optimal first matching layer and performing simulation analysis to obtain the optimal second matching layer. This design method is low-cost and time-consuming.

An air coupling ultrasonic excitation device for testing dynamic characteristics of a wafer-level MEMS microstructure comprises an ultrasonic probe, a laser and a rectangular frame, and a plurality of fixing modules are evenly distributed on the circumference of the rectangular frame. An X-axis sliding assembly and a Y-axis sliding assembly are installed on the lower portion of the rectangular frame, and an ultrasonic excitation module is fixed to the Y-axis sliding assembly. The ultrasonic vibration excitation module comprises a mounting bottom plate, a CCD camera is arranged on the mounting bottom plate, a mounting seat is supported on the mounting bottom plate, a lens at the upper end of the CCD camera is inserted into the mounting seat, through holes are formed in the peripheral side walls of the mounting seat respectively, and the two lasers are inserted into the two through holes respectively; and an ultrasonic probe and a lighting source are respectively inserted into the other two through holes and intersect with the axes of the two lasers at one point. The device can be applied to the dynamic test of the wafer-level MEMS microstructure, ultrasonic waves can be quickly and accurately focused on the surface of the microstructure to be tested, and non-contact excitation of any microstructure on an MEMS wafer is achieved.

This invention relates to the field of composite material repair technology, specifically to a robotic repair device for composite material structures. The device includes a composite material repair integrated module and a composite material repair robot structure. The integrated module comprises a detection module, a grinding module, a layup module, and a curing module. The detection module includes a vision system and air-coupled ultrasonic testing, enabling the detection of surface and internal defects and damage characteristics of the composite material repair structure and the establishment of a digital model. The grinding module, through its spherical universal joint and telescopic push rod design, allows for the grinding of irregularly shaped, non-planar structures. Under the control of a microcomputer, the grinding module can automatically grind the repair area based on the defect damage characteristics identified by the detection module. The layup and curing modules can automatically lay up and cure prepreg in the ground area. Simultaneously, the detection module can evaluate the surface quality and internal structure of the repaired composite material defects.

The invention relates to a PE pipeline ultrasonic detection device and method, the device comprises a support mechanism, an adjusting structure, a support arm mechanism, a rotating mechanism, a transverse moving mechanism, a transmission mechanism and a driving mechanism, an annular support sleeves a pipeline, and an electric push rod adjusts the support arm mechanism to realize contact between a rubber wheel and the pipeline; the laser ultrasonic excitation module emits pulse laser to excite nonlinear ultrasonic waves, and the air coupling sensor array synchronously rotates to collect all-circumferential signals; the transmission mechanism drives the rotating ring to achieve 360-degree dynamic scanning through bevel gear transmission, and the servo motor controls the laser module to move axially. The detection method comprises the steps of equipment deployment, full circumferential scanning, nonlinear parameter extraction and intelligent defect identification, modal guided waves are separated by adopting synchronous compression wavelet transform, multi-modal features are analyzed in combination with a CNN-LSTM network, the limitation of traditional contact type detection is broken through, and efficient detection in a non-contact and under-pressure environment is achieved.

The invention discloses a high-temperature-resistant air coupling type ultrasonic transducer without an adhesion layer. The high-temperature-resistant air coupling type ultrasonic transducer comprises a sealing shell, a sealing cover plate, a prestressed bolt, an insulating spacer, piezoelectric ceramics, a matching layer and an insulating wrapping layer, the matching layer is arranged at the front end in the sealing shell, the piezoelectric ceramic is arranged behind the matching layer, and the front end face of the piezoelectric ceramic is attached to the back face of the matching layer; the insulating wrapping layer wraps the outer periphery of the piezoelectric ceramic, and an insulating spacer is arranged behind the piezoelectric ceramic; the prestressed bolt is arranged behind the insulating spacer; the outer periphery of the prestressed bolt is provided with an external thread, the inner wall of the sealing shell is provided with a matched internal thread, and the external thread of the prestressed bolt is matched with the internal thread of the sealing shell and compresses the insulating spacer, the piezoelectric ceramic and the matching layer, so that the piezoelectric ceramic and the matching layer are tightly attached. The ACUT has high-temperature adaptability, the transmitting sound pressure sensitivity and the receiving voltage sensitivity of the ACUT are improved, and the effective propagation distance is prolonged.

The invention belongs to the field of nondestructive detection and online detection, and particularly relates to a system and a method for nondestructive online detection of a SiCf / SiC composite material based on photoacoustic imaging. According to the invention, the photoacoustic imaging is applied to the nondestructive testing of the SiCf / SiC composite material for the first time, the pulse laser excitation unit and the submersible photoacoustic detection assembly are used in the water immersion scanning system, and through a specific light beam shaping light path and the submersible detection assembly, the nondestructive testing of the SiCf / SiC composite material is realized. The problems of large signal attenuation, strong interface reflection and the like of a composite pipe under air coupling are solved.

The invention relates to the technical field of silk making, in particular to combined silkworm chrysalis killing processing equipment which is used for killing silkworm chrysalis in the initial stage of fresh cocoon drying and comprises a processing main body and a belt conveyor, a processing cavity for processing silkworm cocoons is formed in the processing main body, and the processing main body is provided with a moisture exhausting and air exhausting device communicated with the interior and the exterior of the processing cavity; an upper belt of the belt conveyor horizontally penetrates through a machining cavity in the machining body, and the head and the tail of the belt conveyor are both exposed out of the machining body. A plurality of medium wave infrared emitters and a plurality of air coupling ultrasonic emitters are arranged in the processing main body, and the infrared emitters and the ultrasonic emitters are arranged above an upper belt of the belt conveyor. The equipment can be used in cooperation with a conventional hot air circulation silkworm cocoon drying machine and can also be used in cooperation with drying equipment for microwave drying of silkworm cocoons and the like. The equipment realizes uniform heating inside and outside the cocoon shells, avoids the problem of instantaneous overheating of the cocoon shells caused by traditional hot air microwaves and the problem of pupa explosion of microwave-dried silkworm cocoons, and protects the quality of the cocoon shells.

The utility model relates to the technical field of ultrasonic detection equipment, in particular to a layering defect detection device based on air coupling, which comprises a scanning piece, a scanning frame, an ultrasonic probe and a placing piece, the scanning frame is arranged at one end of the scanning piece, and the ultrasonic probe is fixedly mounted at the bottom of the scanning frame. The scanning frame comprises a scanning piece, a feeding piece is arranged at the position, located below the ultrasonic probe, of one side of the scanning piece, a pre-amplifier is arranged at the other side of the scanning piece and connected with a signal generator through a wire, and a displayer is vertically arranged on the signal generator; an electric telescopic rod is vertically fixed to the output end of the rotating motor. The utility model overcomes the defects that the existing ultrasonic transmitter is vertically arranged, can only scan transversely and cannot scan circumferentially and vertically, so that the ultrasonic transmitter can only scan sheet-shaped CFRP materials transversely and cannot scan cylindrical CFRP materials, and the range of ultrasonic detection of the CFRP materials is influenced.

This invention discloses a non-destructive evaluation method and apparatus for the density of selective laser melting additive manufacturing components. The method includes: exciting an ultrasonic guided wave at a specific frequency in the workpiece under test using an air-coupled ultrasonic transducer; receiving the ultrasonic signal using the air-coupled ultrasonic transducer; analyzing the phase change of the ultrasonic guided wave at the specific frequency; and using a convolutional neural network model to obtain the mapping relationship between the phase change and the density of the test piece, thereby predicting the density of the selective laser melting sample. This invention overcomes the problems of low detection efficiency, high cost, and the need for destructive testing in conventional selective laser melting component density detection methods, achieving non-contact, high-precision, non-destructive testing of the density of selective laser melting components, thus improving detection efficiency, accuracy, and flexibility.

The invention provides a circularly polarized antenna and Internet of Things equipment. The circularly polarized antenna comprises an antenna radiator, a feed wire, a first fixing structure and a second fixing structure. According to the circularly polarized antenna disclosed by the invention, the circularly polarized wave can be effectively generated through the frame body, the first branch knot and the second branch knot in the antenna radiator, so that the problem of polarization mismatch is reduced, and the signal receiving quality and the system communication efficiency are improved. The feed wire and the antenna radiator are matched with a proper projection coincidence area, and an air coupling feed mode is adopted to transmit energy to the antenna radiator, so that efficient signal transmission and excellent circular polarization characteristics of the circularly polarized antenna are realized. In addition, circularly polarized waves are realized through the structural design of the antenna radiator and the feed wire, so that the circularly polarized antenna is small in size, high in gain and easy to conform.