2235 results about "Doppler us" patented technology

The invention relates to a method for determining at least a flow velocity or a fluid volume flow (5) of a fluid flowing through an implanted vascular support system (1), comprising the following steps: a) carrying out a pulsed Doppler measurement by means of an ultrasonic sensor (2) of the support system (1), b) evaluating a measurement result from step a), which has a possible ambiguity, c) providing at least one operating parameter of a flow machine (3) of the support system (1), d) determining at least the flow velocity or the fluid volume flow (5) using the measurement result evaluated in step b), wherein the possible ambiguity of the measurement result is corrected using the operating parameter.

The invention relates to the technical field of inertial assistance, in particular to a Beidou high-precision space-time reference dynamic compensation system based on inertial assistance, which is characterized in that an inertial measurement unit module is used for measuring original measurement data, and the original measurement data comprises a carrier phase and a Doppler observation value; the processing unit module is used for fusing the inertial measurement unit, executing real-time environment perception and dynamic modeling, classifying an operation environment and predicting error characteristics; performing an adaptive robust fusion filtering algorithm that dynamically adjusts filter parameters and switches a filter model to estimate the position and attitude of the carrier; and in combination with radio wave precision single-point positioning enhancement service, super-tight combination signal tracking and integrity monitoring are realized, an estimated inertial assistance system state is fed back to a tracking loop of the multi-frequency Beidou receiving module, and real-time fault detection is performed on original measurement data.

The invention relates to a method for determining a flow rate of a fluid flowing through an implanted vascular assist system, said method comprising the following steps: a) carrying out a first pulsed Doppler measurement at a first pulse repetition rate by means of an ultrasonic sensor of the assist system; b) carrying out a second pulsed Doppler measurement at a second pulse repetition rate by means of the ultrasonic sensor of the assist system, wherein the second pulse repetition rate differs from the first pulse repetition rate; c) determining the flow rate using measurement results of the first pulsed Doppler measurement and the second pulsed Doppler measurement.

A method and system for determining a regional weakening (RW) value in a blood vessel using ultrasonic imaging. A set of images of a portion of a given patient's body collected over time is received. A set of measurements representing the movement of the tissue of the blood vessel is received, and the set of measurements is determined based on the set of images. The movement of the wall and lumen at least partially indicates strain. A blood flow velocity value in the blood vessel is determined based on a Doppler image, and an RW parameter indicating the state of weakening in a region of the blood vessel is determined based on at least the set of measurements, thrombus burden, and blood flow velocity value. A map showing the circumference of the blood vessel including the regional weakening value and the strain value may be displayed.

The invention discloses an underwater propeller control method and system based on water body environment analysis. The method comprises the following steps: acquiring image data and laser point cloud data of a target water body, and constructing a three-dimensional environment model; initial position information and a target position of the underwater propeller are obtained, and a working path is generated based on environment model analysis; doppler sonar data on a path are collected, water flow information is analyzed, and a deviation correction control instruction is generated; and the instruction transmission quality is analyzed, and an optimal transmission scheme is determined. According to the method, dynamic modeling and analysis of a complex water body environment are realized by fusing multi-source environment sensing data, the path planning precision and autonomous control capability of the underwater propeller are improved, and the method is suitable for precise navigation and dynamic obstacle avoidance scenes in complex underwater operation tasks.

The invention belongs to the technical field of ocean data processing, and discloses a GNSS-R and scatterometer combined same-orbit time sequence sea surface wind speed inversion method and system, and the method comprises the following steps: obtaining historical satellite data of ocean surface wind, carrying out the preprocessing of the historical satellite data, and obtaining the preprocessed data, constructing a training sample set in combination with the reference wind speed and the surge auxiliary data; constructing an initial wind speed inversion model by using a plurality of single-moment multi-frequency information fusion modules and multi-moment interactive attention enhancement modules, and training the initial wind speed inversion model by using the training sample set to obtain a same-orbit time sequence sea surface wind speed inversion model; and obtaining a time delay-Doppler correlation power diagram, GNSS-R observation parameters, scatterometer parameters and effective wave height of storm and surge, and completing sea surface wind speed inversion by using the same-orbit time sequence sea surface wind speed inversion model to obtain sea surface wind speed prediction data.

The invention relates to the technical field of fluid measurement, in particular to a multimode signal fusion and self-adaptive processing ultrasonic flowmeter and a measuring method. The multimode signal fusion and self-adaptive processing ultrasonic flowmeter comprises an ultrasonic transducer, a signal generation driving module, a signal receiving and conditioning module, a control module, a signal processing module, a signal quality evaluation module and a sound velocity calculation and compensation module. According to the method, the time difference method and Doppler method signals are fused, the self-adaptive processing strategy is adopted to improve the measurement precision of the low-flow-velocity fluid and the impurity-containing fluid, the measurement precision of the low-flow-velocity fluid can be remarkably improved, the adaptability to complex fluid is enhanced, the overall measurement reliability is improved, the Doppler method precision is optimized, and the intelligent degree is high.

The invention discloses a laser radar test method based on a long-distance target distance measurement result, and the method comprises the following steps: obtaining a laser radar echo signal, and extracting the frequency spectrum information of the echo signal; doppler frequency shift characteristic parameters are extracted according to the frequency spectrum information, and the relative speed of the target is calculated based on a preset frequency shift calculation model; acquiring multi-source sensor data associated with the laser radar test platform, and fusing to construct a dynamic ranging reference coordinate system; performing dynamic motion compensation on a laser ranging result according to the relative speed of the target to obtain a target initial measurement distance after Doppler correction; mapping the target initial measurement distance after Doppler correction to the dynamic distance measurement reference coordinate system to obtain a remote target final distance measurement result aligned with a test platform coordinate system; and outputting the accurate position and moving state information of the target in the three-dimensional space according to the final distance measurement result. According to the invention, the ranging precision and stability can be improved.

The invention discloses a multipath ghosting suppression method for a millimeter-wave radar tunnel scene, which is applied to the field of millimeter-wave radar target detection and aims to solve the problem of poor multipath ghosting suppression effect in the tunnel scene in the prior art. The method comprises the following steps: firstly, constructing a confidence criterion by using multi-dimensional information point cloud data generated by radar original echoes, and performing density-based clustering on the point cloud data; performing linear fitting on the zero Doppler point cloud to obtain slope information of the tunnel wall, matching the slope of the perpendicular bisector of the dynamic point cloud pair with the slope set, and judging the target pair with lower confidence in the successfully associated target pair as a multipath ghosting; and finally, in consideration of motion characteristics of targets in the tunnel and a multipath reflection geometric model, performing transverse and longitudinal double-rectangular region division on the dynamic point cloud, performing Doppler information constraint on point cloud data in the region, and screening out the targets which meet conditions and are relatively low in confidence coefficient and judging the targets as multipath ghosts. According to the invention, vehicle targets in a semi-closed environment can be detected, and multipath ghosts generated by reflection of tunnel walls, handrails and the like can be effectively identified and inhibited while real targets are reserved.

The invention provides an underwater ultrasonic Doppler real-time analysis method and device based on a digital transducer, and relates to the technical field of data analys.The method comprises the steps that 1, multiple beams of directional ultrasonic waves are emitted into drilling fluid through a digital transducer array on the outer wall of a marine riser, echo signals reflected by gas-liquid two-phase flow are received, and the digital transducer array is used for receiving the echo signals; performing real-time digital conversion on the echo signal to generate an original digital signal containing phase and amplitude information; 2, Doppler frequency shift feature extraction is conducted on the original digital signals, and the real-time movement speed and direction of bubbles in the drilling fluid are determined by calculating the frequency deviation of reflected ultrasonic waves and transmitted ultrasonic waves. Through the digital transducer array and the ultrasonic Doppler technology, accurate measurement of motion parameters of bubbles in drilling fluid, real-time calculation of local gas content and early warning and grading response of gas cut are achieved, and the safety and the intelligent level of drilling operation are improved.

The invention relates to the technical field of air target prediction, in particular to an air target trend prediction method, which comprises the following steps: S1, multi-source heterogeneous data adaptive fusion filtering processing; s2, manifold learning is constructed in the high-dimensional spatial-temporal feature space; s3, performing semantic modeling on the dynamic behavior pattern recognition intention; and S4, multi-dimensional threat situation assessment warfare area modeling is carried out. According to the method, high-precision space-time synchronization and noise suppression of radar sensor data, infrared sensor data and other sensor data are achieved through the multi-source heterogeneous data self-adaptive fusion filtering technology, target micro-Doppler features are effectively reserved, missing data are repaired, and through the combination of third-order Savitzky-Golay differential filtering and short-time Fourier transform, high-precision space-time synchronization and noise suppression of radar sensor data and infrared sensor data are achieved. An 18-dimensional compression feature space containing kinematics and electromagnetic characteristics is constructed, a nonlinear topological relation is reserved through t-SNE and an automatic encoder, the signal-to-noise ratio and feature expression capacity of original data are remarkably improved through the function, and a high-precision and low-redundancy input basis is provided for follow-up behavior recognition and prediction.

The invention relates to an unmanned aerial vehicle detection countering method, which comprises the following steps of: deploying a multi-dimensional sensing network to carry out full-band instantaneous scanning, synchronously acquiring noise characteristics of radio signals, material characteristics of a terahertz wave band and Doppler effect characteristics, mapping to a virtual twinborn body, reconstructing physical parameters, a communication protocol and a behavior mode of a target unmanned aerial vehicle, performing depth comparison by combining a disguise sample library generated by the antagonism generation network, and generating a holographic target file containing a three-dimensional motion vector, an energy feature and a potential threat intention; a target quantum encryption communication link is interfered through a quantum entanglement signal, a controllable plasma cloud cluster is generated, navigation and image transmission signals of the controllable plasma cloud cluster are selectively attenuated, the controllability of the target is judged, and an uncontrollable target is repelled through coded sound waves; and sending a control instruction containing a biological heuristic obstacle avoidance algorithm in stages, and guiding the control instruction to an intelligent recovery cabin. According to the invention, accurate detection, intelligent identification, safe countering and reliable takeover of the unmanned aerial vehicle are realized, and the airspace safety guarantee capability is improved.

The invention relates to a method for determining at least a flow velocity or a fluid volume flow of a fluid flowing through an implanted vascular support system, comprising the following steps: a) carrying out a pulsed Doppler measurement by means of an ultrasonic sensor of the support system, b) evaluating a measurement result from step a), which has a possible ambiguity, c) providing at least one operating parameter of a flow machine of the support system, d) determining at least the flow velocity or the fluid volume flow using the measurement result evaluated in step b), wherein the possible ambiguity of the measurement result is corrected using the operating parameter.

The invention belongs to the technical field of radar signal processing, and discloses a radar scattering rapid test method based on polarization decomposition. Comprising the following steps: scanning a target 3D model, simulating scattered field distribution in different incident angles and polarization modes, calculating polarization contrast, and identifying a polarization sensitive area; establishing a dynamic coordinate system conversion model, fusing RTK data, IMU data and laser tracking data, and correcting the position of the trolley and the model in combination with a Doppler frequency shift model and a least square method; calculating an optimal test path of the trolley according to the sensitive area by adopting a natural heuristic optimization algorithm; establishing a geometric environment model, obtaining a back scattering signal through beam forming, analyzing a polarization coherence matrix, obtaining a high-entropy region, and decomposing scattering components; according to the method, closed-loop optimization is formed from a data acquisition source to a scattering component analysis tail end, and the test efficiency and the real-time performance are remarkably improved.

The invention discloses an optical time stretching sweep frequency interference measurement Doppler effect compensation method and device, and relates to the technical field of non-cooperative target absolute distance measurement. In order to solve the defect that the absolute distance measurement precision is reduced due to the fact that the Doppler effect cannot be efficiently suppressed in a complex environment in the prior art, the technical scheme provided by the invention comprises the following steps: generating a sweep frequency laser signal and splitting the sweep frequency laser signal to form measurement light, reference light and resampling light; performing time stretching processing on the reference light to obtain a chirp signal; performing interference on measurement light and the chirp signal to obtain a measurement interference signal; performing interference on the reference light and the resampling light to obtain a reference interference signal; performing cross-correlation processing on the measurement interference signal and the reference interference signal, and extracting an optical path difference; and carrying out distance calculation by combining the resampling data, and outputting a target distance after the Doppler effect is compensated. The method is suitable for optical measurement work for performing high-precision absolute distance measurement on a non-cooperative target in a tiny vibration or disturbance environment.

The invention relates to the technical field of communication, and discloses a high-precision measurement method for radial velocity of a shallow sea underwater acoustic target based on ray sound field reconstruction. According to the method, a multipath channel joint resolving system is innovatively constructed for the problem that the target speed measurement precision is limited due to a shallow sea complex propagation environment. According to the system, a compound ray model of shallow sea multipath sound propagation is established, and a joint representation equation containing channel impulse response and target motion parameters is constructed by analyzing a time delay-Doppler coupling mechanism of three typical paths of direct waves, water surface reflected waves and water bottom reflected waves. Especially for the multipath interference effect in the shallow sea waveguide environment, the time-frequency domain separation criterion of each path signal is deduced, and a theoretical basis is laid for feature information extraction. The method provides a new technical means for underwater target tracking and positioning, underwater acoustic communication Doppler compensation and marine environment dynamic monitoring, and particularly has an important application prospect in the fields of underwater unmanned cluster collaboration and the like.

The invention relates to the technical field of laser radars, in particular to an obstacle detection method and system based on a frequency-modulated continuous wave laser radar, and the method comprises the steps: transmitting a chaotic frequency-modulated continuous wave signal to a detection region, and obtaining a reflection echo signal of a target object; performing decoupling calculation on the difference frequency electric signal to obtain a target time frequency distribution matrix; according to the target time-frequency distribution matrix, predicting the Doppler frequency shift amount of the target object at the next moment; based on the chaos frequency modulation adjustment signal, obtaining a distance measurement deviation compensation amount; the chaos frequency modulation adjustment signal is obtained by dynamically adjusting the chaos frequency modulation slope of the chaos frequency modulation continuous wave signal through the Doppler frequency shift amount; and compensating the difference frequency electric signal frequency value of the target object according to the distance measurement deviation compensation amount and the environmental noise data so as to solve obstacle distance speed detection information. According to the invention, the Doppler frequency shift amount is predicted in real time and the chaotic frequency modulation continuous wave signal parameters are dynamically adjusted, so that the accurate compensation of the distance measurement deviation is realized, and the accuracy of obstacle distance speed detection is improved.

The invention provides a concrete spraying rebound rate optimization decision-making method and a concrete spraying rebound rate optimization decision-making system. The method comprises the following steps: firstly, collecting and extracting time-frequency characteristics in a jet impact acoustic emission signal, collecting laser Doppler array measurement data in a concrete jet process to obtain concrete flow velocity distribution, then carrying out multi-source fusion processing on the time-frequency characteristics and the concrete flow velocity distribution, and extracting principal component characteristic vectors associated with springback; the method comprises the following steps: firstly, constructing a main component feature vector, then constructing a space velocity field model to obtain an identification result representing a concrete rebound state, then carrying out clustering analysis on the main component feature vector and the identification result, identifying a high rebound mode category and a low rebound mode category to generate a risk partition map, and finally, dynamically generating a jet parameter adjustment instruction by applying a self-adaptive control algorithm. Outputting a concrete rebound rate optimization decision scheme; according to the technical scheme provided by the invention, the problem of feature drift caused by space-time asynchronization of physical field data is solved, and the overall rebound rate prediction precision is greatly improved.

A hybrid time domain multiplexing (TDM) and frequency domain multiplexing (FDM) configuration protocol for a doppler-based ultrasound fetal monitoring system (FMS) is provided. In an example, a FMS determines context information regarding an operating context of the FMS, the context information comprising a number of fetal sensor devices (FSDs) activated for monitoring a corresponding number of fetuses of a single mother, wherein the FSDs respectively comprise ultrasound transducers configured to measure fetal parameters of a single fetus, and wherein each of the FSDs are configurable to operate using either the FDM mode or the TDM mode. The FMS further configures respective operating modes (i.e., FDM mode or TDM mode) of the FSDs based on the context information and in accordance with a configuration protocol that varies the respective operating modes (i.e., FDM mode or TDM mode) of the FSDs under different operating contexts of the FMS.

The invention discloses a femoral artery paracentesis post-operation pressure-controlled hemostasis device and a monitoring intelligent control system thereof, and relates to the technical field of medical apparatuses and instruments, and the femoral artery paracentesis post-operation pressure-controlled hemostasis device comprises an assembly panel; the air bags are arranged at the bottom of the assembly panel; the air pump is arranged at the top of the assembly panel and used for controlling the air bags to contract; the control piece is arranged at the top of the assembly panel and used for controlling the air pump; the Doppler probe is arranged at the bottom of the assembly panel and used for detecting the blood flow speed of the far end of a puncture point, the hemostasis safety and efficiency are remarkably improved through multi-mode intelligent control and a real-time feedback mechanism, the vein area is accurately recognized and avoided in combination with ultrasonic and infrared spectrum analysis of the artery positioning module, the thrombus forming probability is effectively reduced, and the blood flow speed of the far end of the puncture point is detected. The pressure-time optimization model dynamically shortens the compression time (target 3 hours) based on the real-time hemostatic effect, and improves the comfort of the patient while ensuring the hemostatic effect.

The invention discloses an SAR sea surface flow velocity inversion method based on physical guidance and data driving fusion, and relates to the field of flow velocity inversion, and the method comprises the steps: carrying out the non-geophysical Doppler frequency shift correction of the Doppler frequency shift observed by a spaceborne synthetic aperture radar, and obtaining the geophysical Doppler frequency shift; predicting based on a wave-induced Doppler frequency shift model according to a radar incident angle, reanalyzed wind direction data, a sea surface 10-meter height wind speed inverted by an SAR (Synthetic Aperture Radar), a simulated wind wave parameter, a simulated surge parameter and a simulated maximum wave parameter to obtain a wave-induced Doppler frequency shift; the wave-induced Doppler frequency shift model is obtained based on physical guidance and data-driven modeling; doppler frequency shift generated by sea surface flow is determined according to the geophysical Doppler frequency shift and the wave-induced Doppler frequency shift; according to the method, the Doppler frequency shift generated based on the sea surface flow is converted to obtain the sea surface radial flow velocity, the wave-induced Doppler frequency shift is accurately removed, and reliable inversion of the sea surface flow velocity is realized.

The invention discloses an acoustic Doppler flow velocity measurement method and system, and the method comprises the steps: generating an emission parameter combination adaptive to a current hydrological environment according to the depth characteristics and precision requirements of a target water area; original echo signals are collected based on the emission parameter combination, and a three-dimensional flow velocity vector of temperature compensation is output; inputting the three-dimensional flow velocity vector into the dynamic segmentation network to generate a layered flow velocity distribution model; calling a layered flow velocity distribution model, fusing fluxgate compass azimuth data to carry out flow direction compensation, triggering a deviation correction algorithm when equipment inclination exceeds a limit, and outputting absolute flow velocity distribution of pose calibration; and according to absolute flow velocity distribution and echo intensity dynamic range constraint, calculating an error interval of each depth unit, and outputting a final flow velocity profile with confidence identification. According to the embodiment of the invention, the environmental adaptability and data reliability of flow velocity measurement can be improved.

The invention relates to the technical field of flow chart automatic testing, and provides a flow chart automatic testing method, system and device of a control system and a storage medium so as to solve the problems of low testing efficiency and poor accuracy. The method comprises the following steps: acquiring a film thickness and transverse tension fluctuation curve by using an intelligent textile sensor array, generating a tension compensation factor based on a phase difference to correct the film thickness, and establishing a thickness distribution topology model; performing non-contact scanning by using a terahertz wave emission array, and activating a defect mark cluster when Doppler frequency shift is detected; transmitting the thickness distribution model and the defect characteristics to a test platform, reconstructing a control logic and generating a test script, and realizing a virtual-real synchronous test through a communication protocol; and generating a process parameter correction factor according to a test result, and feeding back the process parameter correction factor to the distributed control system to optimize the tension closed-loop control module, and generating a matched terahertz verification map. According to the technical scheme provided by the invention, the efficiency and accuracy of automatic testing of the flow chart can be improved.

The invention discloses an ultrasound-based diabetic renal lesion risk detection method and system, and relates to the technical field of ultrasonic detection.According to the system, through continuous scanning of a two-dimensional ultrasonic probe, an elastic imaging probe and a Doppler probe, the shape, structure, blood flow characteristics and cortex images of the kidney are obtained; an image processing technology is adopted for preprocessing, space registration and fusion, and a kidney area is automatically segmented; according to the extracted kidney tissue characteristics, calculating an atrophy risk coefficient and a fibrosis risk coefficient, and comparing with a standard threshold value to evaluate the kidney lesion risk; calculating a comprehensive risk coefficient in combination with blood glucose, urine protein and diet data, and evaluating diet influence risks; a renal lesion risk assessment model is constructed by using a convolutional neural network and a machine learning algorithm, a renal lesion prediction function is generated, and the system can accurately assess the renal lesion risk of a diabetic patient and provide early diagnosis and personalized treatment suggestions.

The invention discloses a signal acquisition and processing method and system based on a multifunctional radar, and relates to the technical field of signal acquisition and processing, and the method comprises the steps: employing a quantum genetic algorithm to optimize radar transmission waveform parameters, including center frequency, bandwidth and frequency modulation slope, and generating a nonlinear frequency modulation waveform through FPGA hardware; a non-uniform sparse array is adopted to receive a target echo signal, time domain random interval sampling and frequency domain pseudo-random frequency point selection are synchronously implemented, and time-space-frequency three-dimensional compressed sensing observation data are formed; performing trilinear tensor joint sparse reconstruction on time-space-frequency three-dimensional compressed sensing observation data, decomposing a polarization scattering matrix eigenvalue from a reconstructed signal, and calculating a coupling characteristic quantity of eigenvalue entropy and micro-Doppler frequency; inputting the coupling characteristic quantity into a deep reinforcement learning model, and dynamically outputting a constant false alarm detection threshold, a moving target display filter order and a resource allocation weight; and detecting a threshold based on a constant false alarm rate.

The invention relates to the field of ocean current remote sensing, and relates to a vector flow inversion method combining a single-station ground wave radar and a satellite-borne SAR, and the method mainly comprises the steps: calculating the frequency deviation of a first-order Bragg peak of the ground wave radar, carrying out the inversion of the sea surface radial flow of the ground wave radar, and carrying out the inversion of the sea surface radial flow of the SAR through employing a Doppler centroid anomaly method; interpolating a ground wave radar radial flow result to an SAR data grid through bilinear interpolation; inverting a single-station vector flow based on a ground wave radar radial flow result, projecting single-station vector flow data with high confidence coefficient to an SAR range direction, calculating a difference mean value of a projection flow velocity and an SAR radial flow velocity, and further calibrating the SAR radial flow; and combining a ground wave radar radial flow result with the calibrated SAR radial flow to invert a vector flow. According to the method, the defect of ocean current observation through a single means is overcome, high-precision inversion of the combined vector flow is achieved, and the method has important significance on ocean environment monitoring, disaster forecasting, shipping safety and the like.

A method for CLI signal measurement includes: receiving, at an apparatus, a CLI configuration indicative of an uplink CLI signal corresponding to a transmitting user equipment; receiving, at the apparatus, the uplink CLI signal; measuring, at the apparatus, the uplink CLI signal to determine a Doppler measurement; and measuring, at the apparatus, the uplink CLI signal to determine a received power of the uplink CLI signal.

The present application provides a method for determining the spatial distribution of an echo signal, a communication node and a storage medium. The method comprises: receiving an echo signal, and calculating a delay Doppler map of the echo signal; extracting environment data in the delay Doppler map, determining a distance parameter, an angle parameter and an energy parameter corresponding to each sample point in the environment data, and on the basis of the energy parameter, extracting an echo signal component in the environment data; on the basis of the echo signal component, determining a reflection point position of the echo signal; and on the basis of the reflection point position and the intensity of the echo signal, drawing a spatial distribution diagram of the echo signal in three-dimensional space.

The invention relates to the technical field of intelligent detection, and discloses a single-point laser Doppler-based explosion-proof shell pressure resistance dynamic detection method and system, and the method comprises the steps: building a detection system through arranging a plurality of laser Doppler vibration meters and a data collection system, and enabling the detection system to be used for the pressure resistance dynamic detection of an explosion-proof shell; analyzing the structure of the explosion-proof shell, outputting a finite element analysis result, determining a key area needing to be measured, and setting a plurality of measurement points based on the key area; carrying out single-point acquisition on each pre-selected measuring point in sequence, during each acquisition, carrying out a withstand voltage test on the explosion-proof shell through withstand voltage test equipment, and detecting the measuring points through a laser Doppler vibration meter to generate vibration data; and the data acquisition system records vibration data of each measurement point. According to the invention, through the single-point laser Doppler vibration measurement technology, the measurement requirements of the dynamic parameters of the explosion-proof shell can be met.