393 results about "Piezoelectric sensor" patented technology

The invention discloses a sleep state real-time monitoring method and system, and belongs to the technical field of sleep monitoring, and the method specifically comprises the steps: collecting a heart rate variability signal, an electroencephalogram signal and body movement data of a user in real time through a non-invasive sleep pad integrating a piezoelectric sensor, a flexible dry electrode and a pressure sensor; based on the physiological data, whether the user reaches an autonomous sleep state or not is judged through a first algorithm model; if not, starting an active intervention program for playing the adjustable music, and dynamically adjusting the music volume, the playing speed or the track in combination with the physiological data feedback until the user enters an autonomous sleep state; after the user falls asleep, physiological data are continuously collected, and a sober period, a light sleep period, a deep sleep period and a rapid eye movement period are divided through a second algorithm model; if the staging result is a waking period, the autonomous sleep state judgment is executed again; according to the invention, non-intrusive monitoring and personalized intervention are combined, and the monitoring comfort and accuracy are improved.

The invention discloses a rotating machine vibration protection method and system of an adaptive resonance neural network, and the method comprises the steps: collecting a millisecond vibration acceleration signal of a rotating machine through a distributed piezoelectric sensor array, obtaining the real-time working condition parameter of equipment, and generating a time-work synchronous vibration signal flow; inputting the time-work synchronous vibration signal flow into a resonance neural network, and dynamically generating a frequency domain-time varying adaptive threshold group in combination with the working condition parameters; extracting a weak impact resonance characteristic tensor by using a multi-scale resonance kernel of the resonance neural network; projecting a weak impact resonance characteristic tensor to an orthogonal fault subspace through a tensor decomposition algorithm, and separating out a decoupling fault characteristic matrix; and generating a real-time protection decision instruction set based on a comparison result of the decoupling fault feature matrix and the equipment operation historical database. According to the embodiment of the invention, the method can improve the detection sensitivity and positioning precision of a weak fault under an unsteady working condition, and achieves the real-time adaptive optimization of the vibration protection of the rotating machine.

The invention relates to the technical field of deep learning, in particular to a dialysis hypotension risk prediction system and method based on deep learning, and the system comprises a multi-point signal collection module, a signal processing module, a multi-scale causal expansion convolutional network prediction module, an osmotic pressure correction module and a dialysis plan automatic adjustment module. The method comprises the following steps: synchronously collecting physiological signals of a patient through a finger tip photoelectric volume sensor and a radial artery piezoelectric sensor array, carrying out band-pass filtering and morphological refinement processing on the signals, extracting features, and calculating pulse wave conduction time and a change rate thereof; inputting the characteristic parameters into a multi-scale causal expansion convolutional network to predict the hypotension risk in dialysis; dynamically correcting the prediction result according to electrolyte monitoring data; based on the corrected risk, a hierarchical response strategy is adopted to automatically adjust dialysis parameters, a multi-scale causal expansion convolutional network is adopted to capture physiological parameter changes on different time scales at the same time, and high-precision prediction of hypotension is achieved.

Sensor modules mountable on a wheel are described with methods of use. A sensor module for a wheel includes a base module mountable to a rim. The sensor module further includes a first set of piezoelectric sensors coupled to the base module at a first side and a second set of piezoelectric sensors coupled to the base module at a second side. A method includes receiving a first force from a tire on a piezoelectric sensor mounted on a rim, the force resulting from an inflation of the tire and causing a first strain on the sensor. The method further includes receiving a second force on the sensor corresponding to a deformation of the tire due to surface contact, where the second force causes a second strain. The method also includes generating wheel data from electrical signals produced by the sensor; and transmitting the wheel data to a remote device.

The invention discloses a self-adaptive vibration suppression vortex shedding flowmeter and a method. The self-adaptive vibration suppression vortex shedding flowmeter comprises a flowmeter shell, a pipe connecting flange, a vortex shedding generator and a piezoelectric sensor, the piezoelectric sensor is embedded into the damping device, the damping device restrains measurement vibration of the piezoelectric sensor, the free end of the piezoelectric sensor is connected with a detection probe, and the detection probe prevents a medium in a flow field from making contact with the root of the detection probe through a joint ring; an inner cavity is formed in the vortex street generating body, and a temperature sensor is integrated in the inner cavity to sense the temperature of fluid flowing through the vortex street generating body in real time; according to the invention, the temperature sensor is integrated in the vortex street generator, so that accurate sensing and real-time compensation of the temperature of a core flow field are realized; multi-stage vibration isolation is constructed through the damping device, the vibration isolation pad, the damping device protection shell and the top base at the same time, and vibration interference is reduced. Due to the optimal design of the detection probe, the durability is improved, and the adverse effect of vibration on signals can be reduced; and the applicability in a complex environment and the reliability of long-term operation are obviously enhanced.

The invention discloses a wide-temperature-range solid insulation space charge measurement method, and belongs to the technical field of electrical insulation test and dielectric physical measurement. A solid insulation sample is mounted between double-layer composite electrode modules in a closed high-low temperature test cavity, and a flexible compensation gasket is adopted to absorb thermal expansion difference; a PID closed-loop control system is utilized to realize accurate and stable control of the temperature of the sample in a wide temperature range; applying a direct-current bias voltage and pulse voltage superposition signal, and collecting an acoustic signal generated by space charge displacement through a wide-temperature-range PVDF piezoelectric sensor module; and based on a sound velocity and sensitivity temperature calibration curve established by a pre-experiment, carrying out deconvolution processing on a sound wave signal to correct a temperature dependence error, and finally obtaining accurate space charge density distribution at different temperatures. According to the invention, the precision and reliability of space charge measurement of the solid insulating material in a wide temperature range are effectively improved.

Apparatus and associated methods relate to autonomous devices configured to inspect surface topologies of airfoils of a gas turbine engine. The autonomous device moves across the airfoil while remaining coupled thereto while sensing the surface topology of the airfoil using a plurality of topological sensors. Each of the plurality of topological sensors includes a piezoelectric sensor that generates an electrical signal indicative of a loading to the piezoelectric sensor, as well as an airfoil contacting member. The airfoil contacting member extends between the piezoelectric sensor and the airfoil when the body is coupled thereto. The airfoil contacting member provides changes to the loading to the piezoelectric sensor in response to changes in the surface topology of the airfoil as the body moves thereacross.

Braking device for a vehicle, with a piezoelectric sensor (2) comprising: a piezoelectric material, two electrodes (6, 7), wherein the piezoelectric material comprises a first flat face (4) and a second flat face (5), the faces extending in parallel planes identified by two orthogonal y and z directions, wherein an electrical signal is collected by the electrodes when the piezoelectric material is simultaneously subjected to a normal force in an x-direction and to a shear force in the z-direction, wherein the first electrode is positioned on the first face and the second electrode is positioned on the second face and has extensions (7a, 7b) on the first face separated by the first electrode, wherein each of said extensions extends on a corresponding side of said first face, and wherein each of said extensions is symmetrically configured with respect to a central axis of the first face.

A mirror device includes a mirror portion, a pair of first support portions, a pair of movable frames, a pair of second support portions, a drive portion having a plurality of piezoelectric actuators, a fixed frame, a pair of connecting portions connecting the drive portion and the fixed frame, and a piezoelectric sensor that generates a signal corresponding to swing of the mirror portion around the first axis or the second axis. The piezoelectric sensor is electrically isolated from the plurality of piezoelectric actuators. The plurality of piezoelectric actuators and the piezoelectric sensor are each formed of an upper electrode, a piezoelectric film, and a lower electrode. The upper electrodes of the plurality of piezoelectric actuators are connected in common via a first metal wire. The lower electrode of the piezoelectric sensor is connected to a second metal wire that is electrically isolated from the first metal wire.

The invention provides a method suitable for determining charging parameters in a contour blasting hole, and belongs to the technical field of blasting parameter design. The determination method comprises the steps that a piezoelectric sensor is arranged in a blast hole of a rock mass, one point in the axial direction of the blast hole is a first target point, and a first function relation that the hole wall pressure of the first target point changes along with a first distance is constructed; one point in the rock mass is a second target point, and constructing a second function relation that the stress of the second target point changes along with the first distance and the second distance based on the first function relation. Based on the second function relation, a first curve of the crushed area boundary of the rock mass changing along with the first distance is drawn, a second curve of the fracture area boundary of the rock mass changing along with the first distance is drawn, and a target area is defined by the first curve and the second curve. And through the target area, the charging interval of the blast holes and the distance between every two adjacent blast holes are determined. According to the method, the blasting forming precision of the contour hole can be improved, so that the back break and support cost is reduced.

The invention provides a hafnium-zirconium-oxygen film, a preparation method thereof and a hafnium-zirconium-oxygen film sensor, and belongs to the technical field of piezoelectric sensors, the hafnium-zirconium-oxygen film is prepared from a hafnium-zirconium-oxygen material, the chemical general formula of the hafnium-zirconium-oxygen material is Aly-HfxZr1-xO2, x is greater than or equal to 0.3 and less than or equal to 0.7, and y is greater than or equal to 0.02 and less than or equal to 0.08. The lead-free hafnium-based oxide is selected as a piezoelectric core, HfxZr1-xO2 is adopted as a matrix, Al is doped to stabilize an orthogonal ferroelectric phase and inhibit oxygen vacancy, d33 = 85-95 pC / N within the thickness range of 10-200 nm and reaches 90% of that of an existing PZT film, and the Curie temperature is increased to 600 DEG C and is greatly increased compared with 350 DEG C of the PZT film. And the material is completely free of lead and conforms to the RoHS instruction.

The utility model relates to a self-powered bridge deck pavement waterproof bonding layer crack automatic monitoring device, and effectively solves the problem that a piezoelectric sensor of a steel bridge deck waterproof bonding layer monitoring device of the piezoelectric sensor is easy to disturb and cannot realize autonomous supply of electric energy. According to the technical scheme, the steel bridge deck comprises a steel bridge deck body and a waterproof layer laid on the steel bridge deck body, a self-power-supply module and a monitoring module are arranged between the steel bridge deck body and the waterproof layer, the self-power-supply module comprises self-power-supply columns arranged on the steel bridge deck body, the lower ends of the self-power-supply columns are in lap joint with the steel bridge deck body, and the lower ends of the self-power-supply columns are in lap joint with the waterproof layer. The monitoring module comprises a monitoring layer located between the self-powered column and the waterproof layer; the bridge deck pavement waterproof bonding layer is simple in structure and convenient to install, solves the problems that an existing bridge deck pavement waterproof bonding layer cannot achieve autonomous energy supply and monitoring is not accurate enough, and is convenient to control.

The application relates to the technical field of hoisting devices, in particular to a modular building intelligent hoisting device. The technical scheme comprises a main support assembly, further comprises a hoisting and transporting platform used for bearing a hoisting assembly, the hoisting and transporting platform is slidingly installed in the inside of the main support assembly, the hoisting and transporting platform comprises a main support table, an auxiliary table is rotationally installed at the bottom of the main support table, a spacing adjusting assembly used for adjusting the X-axis spacing is installed at the bottom of the hoisting and transporting platform. The first telescopic rod is used for conducting the pulling force to the piezoelectric sensor for real-time detection of building shaking through the disc-shaped compensation assembly, meanwhile, the Y-axis offset of the modular building is automatically compensated through the linkage hydraulic telescopic rod, the swing caused by wind force and the vibration occurring when the modular building rotates are reduced, the collision risk of the modular building is reduced, and the modular building is particularly suitable for high-altitude operation.

The utility model discloses a piezoelectric sensor excitation symmetrical ultrasonic guided wave mode detection rail damage device belongs to piezoelectric sensor detection technical field, including rail waist testing mechanism, rail bottom testing mechanism and rail top testing mechanism, rail waist testing mechanism, rail bottom testing mechanism and rail top testing mechanism all include support, coupling piece, piezoelectric sensor and limiting component, and two limiting components are connected on the support symmetrically, and two limiting components are located at the both sides of track respectively, and the end of limiting component is connected with piezoelectric sensor, and coupling piece is fixed on the track symmetrically, and piezoelectric sensor is tightly pressed in the side of coupling piece through limiting component. The utility model can press the piezoelectric sensor stably on the different positions of track, and improves the precision of track detection.

One method includes filling a cavity of a mold defined by one or more boundaries with an uncured concrete mix such that the uncured concrete mix comes into contact with or surrounds a piezoelectric sensor within the mold, receiving one or more electrical signals from the piezoelectric sensor as the uncured concrete mix cures within the mold to define a concrete sample, determining an electrical signal frequency spectrum from the electrical signal(s) received from the piezoelectric sensor, determining one or more resonant frequencies of the concrete sample based on the electrical signal frequency spectrum, determining a Young's modulus of the concrete sample based on one or more of its resonant frequencies, and outputting the determined Young's modulus or information based on the determined Young's modulus.

The invention provides a dripping speed detection and alarm device for an infusion apparatus, and belongs to the technical field of medical instruments. The device comprises a fixing frame, a clamping assembly is installed on one side of the fixing frame, the clamping assembly is used for clamping a drip cup part on an infusion tube, the clamping assembly comprises two clamping plates, and a piezoelectric sensor is embedded in the inner wall of one clamping plate; a spring rope is fixedly installed at the lower end of the fixing frame, a connecting block is fixedly installed at the lower end of the spring rope, a single-chip microcomputer is installed on the upper side in the connecting block, and the piezoelectric sensor is connected with the single-chip microcomputer through a wire. A cavity is formed in the lower side in the connecting block, a trigger assembly is installed in the cavity, the single-chip microcomputer is in linkage with the trigger assembly, and first switches are fixedly installed at the two ends of the inner wall of the cavity; an alarm is fixedly mounted at the upper end of the connecting block; a body temperature detection assembly is installed at the lower end of the connecting block and is in linkage with the triggering assembly. The dripping speed of the liquid medicine or the detected body temperature can trigger the first switch, so that the alarm gives an alarm to remind to adjust the dripping speed, and the risk is reduced.

The invention discloses a railway vehicle impact positioning method, device and equipment and a medium, and relates to the technical field of computers, and the method comprises the steps: obtaining a guided wave signal outputted by each piezoelectric sensor when a to-be-detected composite material of a railway vehicle is impacted; the piezoelectric sensor is arranged on the surface of the composite material to be detected; constructing a positioning model based on the installation position of each piezoelectric sensor and the flight time of the guided wave signal, and determining an error function of the positioning model; the function is used for quantifying the deviation between the theoretical distance and the actual distance; the theoretical distance is obtained based on the assumed coordinate of the potential impact point and the mounting position of the piezoelectric sensor, and the actual distance is obtained based on the flight time and the propagation speed of the guided wave signal; and outputting the optimal coordinate estimation of the potential impact point and the optimal propagation speed estimation of the guided wave signal by minimizing the error function. According to the invention, the inherent error caused by the constant wave velocity is avoided; the engineering implementation cost is reduced; the positioning precision is obviously improved; and the real-time performance of impact positioning is ensured.

The invention relates to a punching device (100) for punching a semi-finished product (101), comprising a first pressing tool (103), a second pressing tool (105), an accommodation region (107) arranged between the first pressing tool and the second pressing tool for accommodating the semi-finished product, a punching drive (109) designed to move the first pressing tool relative to the second pressing tool in order to punch the semi-finished product accommodated in the accommodation region, wherein the first pressing tool has at least one temperature sensor (131), at least one piezoelectric sensor (133), at least one position sensor (135), and has a controller (137) designed to detect a wear condition of the first pressing tool and / or the second pressing tool depending on a detected temperature of the first pressing tool, depending on a detected vibration of the first pressing tool and depending on a plurality of detected positions of the first pressing tool.

The utility model discloses an energy -saving type excitation and stir aggregate screening device, including exciting device, piezoelectric device and piezoelectric tray, the exciting device includes the shell, and sets up the eccentric wheel in its inside, a plurality of piezoelectric devices set up in the shell and be located the rotation track of eccentric wheel, and piezoelectric device passes through piezoelectric excitation conversion output electric energy, the piezoelectric tray includes tray frame, screen disc, tray, piezoelectric layer and piezoelectric sensor, the tray frame is connected with eccentric wheel through conducting device, and a plurality of screen discs are stacked from top to bottom on the tray frame, and the tray is set up at the bottom of the last layer screen disc, and piezoelectric layer sets up in the tray, and piezoelectric layer produces piezoelectric excitation signal under the gravity of the aggregate screened by the last layer screen disc, and piezoelectric layer is connected with piezoelectric sensor, and control unit determines the screening completion time according to piezoelectric excitation signal, the device realizes the automatic identification of screening completion time and the self -power supply function, solves the problem, such as long, low efficiency, higher energy consumption of each round screening time in the real test process.

The utility model relates to the technical field of articles for daily use, in particular to a pillow beneficial to sleep, which comprises a pillow body, the pillow body comprises an inward concave pillow part and outward convex vibration parts, the vibration parts are positioned on two sides of the pillow part, and vibration components are arranged in the vibration parts; a sleep-aiding pillow cushion is arranged in the pillow body, and the upper portion of the sleep-aiding pillow cushion is in a trapezoid shape which is arranged in a layered mode and sinks from the two sides to the middle. The top of the pillow body is fixedly connected with a piezoelectric sensor; a plurality of groups of sounding cylinders are arranged on the top of the pillow body and positioned on two sides of the piezoelectric sensor; a data analysis module is arranged at the bottom of the piezoelectric sensor, and the data analysis module is connected with the piezoelectric sensor; a pillow inner is arranged in the sleep-aiding pillow cushion. The sleep condition of the user is judged by detecting the change frequency of the pressure applied to the pillow by the user, and corresponding measures are taken according to the sleep condition to improve the sleep quality and comfort degree of the user.

This invention discloses a milling device for beveling pipes, belonging to the field of pipe milling technology. It includes a mounting housing, a milling force detection unit, a control unit, and a feed execution unit. The milling force detection unit is mounted on the feed assembly of the mounting housing and includes a flange-type piezoelectric sensor electrically connected to the control unit. The control unit receives the output signal from the milling force detection unit and adjusts the feed action of the feed execution unit based on the output signal to dynamically adjust the radial feed of the milling cutter during the pipe beveling process. Adaptive feed adjustment is achieved based on changes in the force on the milling cutter. The milling cutter is driven to feed promptly when the force disappears and stopped promptly after the force recovers, avoiding processing interruptions, overfeeding, and overcutting of the pipe. The entire milling operation can maintain continuous and stable operation without manual intervention.

The application discloses a kind of high-temperature-resistant bifunctional nanogenerator materials and preparation method and application thereof, belong to high-temperature-resistant sensitive material development field;Solve the poor flexibility, single function and lead toxicity of traditional high-temperature piezoelectric sensor and other problems;The application is that piezoelectric polymer polyacrylonitrile and anhydrous acetate are fully mixed in organic solvent and pre-cyclization, then the method of electrospinning is used to prepare flexible nanofiber membrane, and the composite fiber membrane is heat treated, and nanogenerator material is prepared;The nanogenerator material described in the application can work continuously in an environment higher than 450 DEG C, has pyroelectric function, has dual sensitivity to force and heat, and has good flexibility.The preparation method is simple, low cost, environment-friendly and excellent in electrical output performance, and is expected to have good application prospect in the field of force and heat sensitive signal monitoring and sensing in extreme high-temperature environment.

The present application relates to a kind of calibration device and calibration method of shock wave overpressure optical measurement system based on shock tube, it is related to the field of shock wave overpressure test, wherein the calibration device includes: standard shock tube, visible measuring unit;Visible measuring unit includes: transparent quartz tube, first piezoelectric sensor, second piezoelectric sensor, third piezoelectric sensor;Transparent quartz tube one end opening, the other end is closed and is arranged;In the direction from the opening end of transparent quartz tube to closed end, first piezoelectric sensor and second piezoelectric sensor have interval and are embedded in the side wall of transparent quartz tube;Third piezoelectric sensor is embedded in the center of the closed end of transparent quartz tube.This scheme can simply, reliably produce theoretical solvable or accurately measured impact wave overpressure of various shock waves propagation process, can accurately and reliably cross-verify and error determination to the impact wave overpressure obtained in optical measurement process, can accurately calibrate the system error of optical observation wave front propagation process.

The invention discloses a self-energy-supply piezoelectric sensor with a negative Poisson's ratio structure, and relates to the field of wearable flexible sensors. The self-energy-supply piezoelectric sensor adopts a synergistic structural design of negative Poisson's ratio yarn-electrostatic spinning nanofiber membrane-silver nanoelectrode layer; the core pain point of an existing piezoelectric film sensor in human body motion monitoring is solved from the principle level, when human body motion drives the sensor to stretch in the radial direction, the negative Poisson's ratio yarn expands synchronously and transversely, and uniform pressure is generated on the enclosed electrostatic spinning nanofiber membrane; based on a force-electricity coupling effect, deformation of the piezoelectric layer triggers internal polarization charge redistribution, a potential difference is formed between the inner and outer silver nanoelectrode layers, an electric signal is output, self-energization can be realized without an external power supply, and monitoring of movement of a human body or an animal body is realized.

Provided are apparatus and methods for sensing material degradation through sensing of mass accumulation. In some aspects, the apparatus and methods employ a material such as aerogel in conjunction with a force-sensing device such as a piezoelectric sensor placed in contact with or in proximity to a material under test. Degradation of the material under test is sensed by sensing a change in mass of the aerogel absorbing parts or particles of material lost by the unit under test that, in turn, acts to further place force on or deform the piezoelectric sensor enabling real time measurement of degradation by sensing changes in the output voltage of the piezoelectric sensor. These changes in output voltage may then be correlated to the mass degradation of the unit under test.

An oxidation corrosion product thickness on-line measurement method based on a photoacoustic effect comprises the following steps: modulating laser with a specific frequency to irradiate on the CRUD surface of a fuel cladding, monitoring an acoustic wave signal emitted by the CRUD surface by using a piezoelectric sensor, and establishing an on-line conversion model of the acoustic wave signal and the CRUD thickness so as to obtain visual thickness real-time data. On the condition that the original environment of the CRUD is not damaged, online in-situ measurement is carried out on the thickness of the CRUD, and it is ensured that the real thickness of the CRUD in the growth environment can be accurately reflected by measurement data. Through the method, the dynamic growth behavior characteristics of the CRUD thickness can be obtained, so that more accurate monitoring and guidance are provided for safe operation and fuel management of a reactor.

The application relates to a method for evaluating space charge injection characteristics of a polypropylene elastomer blend material for cables. The method comprises: obtaining current information in a to-be-tested sample made of a polypropylene elastomer blend material and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample under a preset test condition; determining space charge distribution information according to the sensor signal information; and determining a space charge injection characteristic evaluation result according to the current information and the space charge distribution information. The method can accurately analyze the real injected current based on the current in the to-be-tested sample under the preset test condition, obtain an accurate charge injection rate, accurately analyze the charge transport in the to-be-tested sample by using the charge injection rate, and thus improve the accuracy of the space charge injection characteristic evaluation result.

The invention relates to a sensor for measuring a parameter of a motor vehicle, comprising an elongate body (10) comprising at least one side (110) extending between distal ends (120D) having a convex shape protruding from said at least one side (110), the body (10) comprises, along the at least one side (110), at least one fluid discharge channel (130) extending from the distal end (120D) to the proximal end (120P), the sensor (1) further comprising a piezoelectric element (20) and a measuring element (30).