1048results about "Force measurement using piezo-electric devices" patented technology

The invention discloses a force and acceleration composite sensor and an adjusting method, and belongs to the field of sensors. According to the technical scheme, the force and acceleration composite sensor comprises a sensor shell, an acceleration detection assembly comprises an acceleration detection core body, a first positioning face and a first pressing block are arranged in the sensor shell, the acceleration detection core body is located between the first positioning face and the first pressing block, and a screwing screw rod is arranged on the first pressing block; a first threaded hole is formed in the sensor shell, and the tightening screw is in threaded connection with the first threaded hole; the force detection assembly comprises a force detection core body, a second positioning surface and a second pressing block are further arranged in the sensor shell, the force detection core body is located between the second positioning surface and the second pressing block, and a jack assembly is arranged on the face, opposite to the force detection core body, of the second pressing block. According to the scheme, an adjustable pressing block structure is added, and adjustment of pre-pressure is achieved; and through the rigid connection mode of threaded connection, the springback phenomenon is avoided, and the pre-compression is more stable and accurate.

The invention belongs to the technical field of flexible sensors, and relates to a flexible temperature and pressure dual-mode sensor and array equipment. The temperature and pressure dual-mode sensor comprises a first flexible substrate, a force-sensitive conductive layer, an interdigital electrode layer, a second flexible substrate, a counter electrode layer and a temperature-sensitive layer which are sequentially stacked; the force-sensitive conductive layer comprises a microstructure layer stacked on the first flexible substrate and a conductive layer stacked on the microstructure layer; wherein the material of the microstructure layer comprises flexible resin and expanded microsphere powder, the interior of the microstructure layer is provided with a microsphere micropore structure formed by expansion of expanded microspheres, and the surface of the microstructure layer is provided with a plurality of protrusions and recesses; the temperature-sensitive layer is connected between the two counter electrodes of the counter electrode layer, and the temperature-sensitive layer is made of graphene.

The invention relates to the technical field of precision machining, in particular to a cutting force signal synchronous calibration method based on multi-sensor data fusion, which comprises the following steps of: 1, dynamically preprocessing acquired signals; step 2, constructing a reference time axis based on the spindle current signal, and realizing time domain alignment of multichannel signals by adopting a dynamic time warping algorithm; 3, establishing a feature incidence matrix containing a force-vibration-temperature coupling relation, and generating a fusion cutting force feature vector through frequency domain energy weight distribution; 4, a dynamic transfer function model is constructed, model parameters are updated in real time, and the fusion feature vector is mapped into a calibration cutting force signal; and 5, carrying out dynamic compensation on the calibration signal by adopting a nonlinear inverse compensation and residual modal screening strategy. According to the method, the accuracy of cutting force signals can be remarkably improved, errors and uncertainty in the machining process are reduced, and the production quality and efficiency are optimized.

The invention discloses a miniature piezoelectric driving type detection contact integrated laser module and a contact type calibration method, particularly relates to the technical field of precision measurement, is used for solving the problem of dynamic time-varying interference of high-voltage driving pulses on micro-force signals, and is an interference coupling path synchronous acquisition and dynamic resolving technology based on a distributed electromagnetic probe. Online identification of transient interference energy distribution characteristics is realized; a multi-dimensional parameter fusion mechanism of an interference-response dynamic model quantifies cross-domain characteristics of interference energy, system response and signal noise into a comprehensive suppression coefficient, and reverse compensation waveform injection and adaptive filter dynamic adjustment are performed, so that full life cycle offset of common-mode noise is realized, and damage of residual interference to closed-loop control is avoided; through cross-domain collaborative analysis of laser-mechanical data, a self-healing iteration mechanism of contact type calibration parameters is established, progressive pollution of dynamic interference to a calibration reference is eradicated, and long-term consistency of detection precision under complex working conditions is ensured.

The invention discloses a self-energy-supply multi-mode sensing electronic skin based on ionic gel heterojunction array integration and a preparation method and application of the self-energy-supply multi-mode sensing electronic skin. The electronic skin adopts a multi-layer composite structure design and comprises an electrode array layer, a silver paste connecting layer, a nano material doped ionic gel array layer and a pure ionic gel continuous layer, and passive self-energized work is realized through a space ion migration effect at a heterogeneous gel interface. The method is characterized in that the design of a multi-layer flexible composite structure is adopted, space-time coded light, temperature, pressure and humidity four-mode stimulation can be synchronously converted into electroneurographic signals, and a collaborative identification strategy of response intensity dynamic range and synaptic learning / delay time difference is utilized; and high-precision decoupling of the multi-source signals is realized in combination with a classification decision tree algorithm. The electronic skin has the characteristics of flexibility, deformation, environment self-repairing and bionic synapse, and geometrical characteristics of a reconfigurable target source are fused through time-space domain multi-modal data.

The invention provides a fiber reinforced structure damage positioning method based on a piezoelectric effect, a fiber reinforced structure is widely applied in multiple fields but is easy to damage, an existing positioning method has defects, and the method comprises the steps of piezoelectric composite material preparation, sensor network construction, signal acquisition and processing, positioning based on a time reversal method and the like. During preparation, specific materials are mixed and stirred and then laid with the reinforced fibers, and the processes of curing molding, polarization, packaging and the like are performed; the sensing network is formed by arranging electrodes on the surface of the composite material; signal acquisition is carried out when the composite material deforms or is damaged under load; and the positioning is to re-excite the acquired signal after time reversal processing, and determine a damage point according to a focusing position. The method has the advantages of high-precision positioning, self-energized real-time monitoring, wide applicability, simple and practical structure and the like, can be applied to various fiber reinforced structures, can effectively solve the problems in the prior art, and has important significance for guaranteeing the safety and reliability of the fiber reinforced structures.

The invention relates to the technical field of fault detection, in particular to a high-voltage connector loosening fault detection method and device and an automobile, and the method comprises the following steps: forming a surface acoustic wave resonator array based on an interdigital transducer array, an acoustic wave resonator and a flexible waveguide; butting a signal source radio frequency cable with the pin interdigital electrode chip, triggering data acquisition, performing Fourier transform on original data, and judging the loosening risk of the connector according to each parameter threshold value; carrying out three-dimensional modeling on the connector plugging interface, carrying out modal analysis on the model, and obtaining surface acoustic wave frequencies, group velocities and phase distribution under different pre-tightening forces so as to identify a contact force abnormal region; based on a multi-stage early warning mechanism, rapid locking is achieved through electrorheological fluid, and displacement is finely adjusted through a magnetostrictive rod. According to the invention, the loosening hidden danger can be quickly and accurately locked, a tight protection system is constructed by multi-stage early warning and mechanical self-locking, and the loosening risk of the high-voltage connector can be greatly reduced from early warning to active intervention.

The embodiment of the invention discloses a flexible piezoelectric sensor packaged by a fish scale microstructure elastomer and a preparation method thereof, the flexible piezoelectric sensor is provided with a flexible main body structure, the flexible main body structure comprises a first packaging layer, a piezoelectric layer, an electrode layer and a second packaging layer, the central area of the first packaging layer is provided with a rectangular notch, and the piezoelectric layer is arranged in the rectangular notch; a rectangular notch is formed in the first packaging layer, an elastomer packaging layer covers the rectangular notch, the elastomer packaging layer comprises a substrate and a fish scale microstructure, and the stress distribution effect of the elastomer packaging layer is optimized through the fish scale microstructure, so that the composite packaging structure of the first packaging layer and the elastomer packaging layer can guide stress to be concentrated in a specific area; the flexible piezoelectric sensor has the advantages that the flexible piezoelectric sensor is provided with the fish scale microstructure, local strain capacity is enhanced, energy dissipation is reduced, the fish scale microstructure comprises a plurality of fish scale microstructure units, the fish scale microstructure units are arranged in an array mode, and sensitivity and response speed of the flexible piezoelectric sensor under the low-pressure or low-frequency condition are further improved.

The invention discloses a displacement monitoring system in underground engineering construction and a monitoring method thereof. According to the system, millimeter-level earth surface deformation is captured in real time through a high-precision GNSS displacement monitoring network, and a sensing-decision-execution closed-loop control system is formed in combination with a three-dimensional pressure sensing array and a dynamic execution mechanism of the intelligent pressure regulating module. And when monitoring that the stress of the supporting structure is unbalanced or the displacement of the surrounding rock is abnormal, the intelligent decision center can generate a pressure regulating strategy within 200 milliseconds to drive the hydraulic servo system and the pneumatic compensation unit to implement accurate pressure correction, so that the displacement expansion trend is effectively inhibited. According to the real-time dynamic balance mechanism, traditional passive early warning is upgraded into active intervention, the sudden collapse risk is reduced by about 60%, and meanwhile material waste caused by excessive supporting is reduced.

The present invention relates to the technical field of measuring electrical variables, and in particular to a multi-dimensional force measurement device that takes into account both static and dynamic measurements. This device solves the technical problems of traditional six-dimensional force sensors, such as complex and cumbersome structures, overall weight, inability to take into account both static and dynamic measurements, and low measurement accuracy. The device comprises a measurement component and a vibration isolation component; the measurement component comprises a base plate, a top plate, and a cantilever beam; the cantilever beam is connected to the base plate, and the cantilever beam is inserted into a limit groove of the top plate through a support arm. The cantilever beam is provided with a uniaxial strain gauge, a first biaxial strain gauge, a second biaxial strain gauge, an X-type piezoelectric crystal, a first Y-type piezoelectric crystal, and a second Y-type piezoelectric crystal; the vibration isolation component comprises a first horizontal support plate, a second horizontal support plate, a multi-layer isolation sleeve, and a support column, and the adjacent isolation sleeve interlayers are filled with elastic material. The device realizes the combination of static and dynamic measurements, and can capture rapidly changing torques and forces while maintaining high accuracy.

The invention discloses a cable GIS terminal stress-strain sensor and a strain monitoring method thereof, and belongs to the technical field of stress-strain monitoring, and the sensor comprises a sensor structure unit which comprises a metal housing, a fixed contact, a movable contact and a piezoelectric element; the signal processing unit is integrated in the integrated circuit shell and comprises a charge collector used for converting a charge signal of the piezoelectric element into an analog voltage signal; the pulse charge discharger is connected to the output end of the charge collector in parallel; the analog-to-digital converter is connected with the output end of the charge collector and is used for converting the analog voltage signal into a digital signal; the serial communication interface is used for outputting digital signals after analog-to-digital conversion; the mounting unit comprises a fixing hole position and an adhesive base which are arranged on the metal shell; the cable GIS terminal stress strain monitoring device is used for monitoring the stress strain of the cable GIS terminal in the operation process so as to reflect typical structure defects appearing in the cable GIS terminal, and online monitoring of the cable GIS terminal equipment is achieved.

The invention discloses an automatic system for brake spring force detection, which relates to the technical field of mechanical engineering and automatic control, and is characterized in that a multi-physics field coupling measurement module adopts a nested force sensor group (a strain gauge and piezoelectric quartz compound) and non-contact displacement measurement, and is combined with a thermal expansion compensation ring to correct temperature influence in real time; the environmental interference suppression module eliminates electromagnetic and thermal interference through an electromagnetic shielding cavity and a temperature control platform; the dynamic error compensation engine realizes drift prediction and physical field fusion by using six-dimensional attitude sensing and edge calculation (LSTM + GPR double-stage model); the self-calibration executing mechanism completes nanoscale positioning and micro-force control based on air flotation driving and the bionic clamping jaw. The method solves the problem of measurement misalignment caused by environmental interference, material thermal deformation and clamping errors in traditional detection, and is suitable for high-precision spring force detection under complex working conditions.

A load sensor that includes: an upper housing having an upper face portion, and a lateral face portion that extends in the thickness direction from an outer periphery of the upper face portion; a lower housing having a lower face portion that faces the upper face portion in the thickness direction, the lower housing being less elastically deformable than the upper housing; and a piezoelectric resonator in a space between the upper housing and the lower housing, wherein an end portion of the upper housing and an end portion of the lower housing are fixed to each other with a crimp such that the upper housing is elastically deformed and causes a preload to be applied by the upper housing to the piezoelectric resonator in the thickness direction.

The invention belongs to the field of MEMS sensors, and discloses a high-temperature-resistant MEMS pressure sensor chip and a packaging structure thereof. The chip is provided with an SOI substrate, an AlN layer and a SiO2 layer from bottom to top, a plurality of P-type piezoresistors are arranged on the uppermost layer of the SOI substrate and are symmetrically distributed at the stress concentration position of the edge of the elastic diaphragm; a channel which continuously penetrates through the AlN layer and the SiO2 layer is arranged above the P-type piezoresistor; a metal Pad is arranged in the channel; the upper end of the metal Pad is located on the uppermost layer of the high-temperature-resistant MEMS pressure sensor chip, and the lower end of the metal Pad is in contact with the P-type piezoresistor. According to the invention, the relatively thick buried oxide layer can resist a high-temperature severe environment, and an AlN heat dissipation material with a high heat conductivity coefficient is deposited, so that rapid heat dissipation at a high temperature is ensured; and meanwhile, the stability and the reliability of the sensor are improved by adopting leadless packaging, and the packaging density is further optimized.

The invention discloses a centripetal force sensor and a using method thereof, and belongs to the field of sensors. According to the technical scheme, the centripetal force sensor comprises a fixed part and a rotating part, the rotating part comprises a sensor shell, the sensor shell is hollow, a center signal column is fixedly installed in an inner cavity of the sensor shell, a plurality of notches are formed in the outer circumferential face of the center signal column, and mass blocks are placed in the notches; piezoelectric ceramics are arranged on the outer side of the mass block, and the piezoelectric ceramics and the mass block are clamped between the inner wall of the sensor shell and the outer wall of the center signal column. The sensor is directly installed at the rotation center of a detected object, additional centrifugal force generated by the mass of the sensor approaches to zero, the authenticity of the detection result is greatly improved, meanwhile, the sensor is in direct conductive contact with the signal output structure through the center signal column, the mouthpiece does not rotate along with the detected object, and the detection accuracy is improved. The winding and pulling faults of the mouthpiece and an external pipeline are completely eradicated, and the durability of the sensor is improved.

A force sensor comprising a contact arrangement for transmitting a contact force to a force sensor assembly. The force sensor assembly comprising a first sensor sensing, and producing an output from, a normal contact force component of the contact force; and a body moveable on transmission of the contact force to the force sensor assembly; and a second sensor for sensing, and producing an output from, a relative displacement of the body relative to the second sensor, the a tri-axis contact force being determined from the relative displacement.

The invention discloses a flexible pressure sensor based on a metal oxide thin film transistor and a preparation method and application thereof. The flexible pressure sensor based on the metal oxide thin film transistor comprises a flexible substrate, a gate electrode layer, a gate dielectric layer, a metal oxide channel layer, a source electrode, a drain electrode and a piezoelectric layer, the piezoelectric layer comprises a piezoelectric polymer, ZnO nanoparticles and MXene nanosheets, and the surface of the piezoelectric layer is provided with a convex micro-nano structure. The flexible pressure sensor based on the metal oxide thin film transistor has the advantages of excellent electrical properties, good flexibility, high sensitivity, easy integration, simple preparation process and low cost, is suitable for the production of large-scale sensor arrays, and has very wide application prospects in the fields of flexible touch screens, human-computer interaction, electronic skin and the like.

The invention relates to the technical field of stress monitoring, in particular to a piezoelectric ceramic system for stress monitoring, which comprises a distributed sensing network module, a stress signal processing module, a stress feature extraction module, an intelligent positioning module and a monitoring feedback module. Mechanical stress is converted into charge signals through a piezoelectric ceramic sensor array and a sensor group, spectrum correlation cross validation is carried out on multiple paths of signals through high-fidelity conditioning and digital processing, and abnormal data are effectively eliminated; vibration mode characteristics are extracted through collaborative time-frequency domain analysis, and damage risk parameters are calculated to distinguish damage types; the intelligent positioning module determines a damage area and endows different confidence levels with the damage area in combination with a sensor spatial topological relation and an abnormal association mode; and the monitoring feedback module executes graded early warning. According to the method, the reliability of monitoring data, the sensitivity of early damage identification and the accuracy of damage positioning are remarkably improved, and intelligent graded early warning based on risk confidence is realized.

The invention provides a high-precision force sensor chip packaging structure and a detection method, and the structure comprises a ceramic pedestal, the top end of the ceramic pedestal is provided with a first accommodation groove, the lower part of the first accommodation groove is provided with a second accommodation groove, the second accommodation groove is communicated with the first accommodation groove, the connection part of the first accommodation groove and the second accommodation groove forms an accommodation area, and the first accommodation groove and the second accommodation groove are communicated with each other. A plurality of internal electrodes are arranged in the accommodating area; one end of the crystal chip in the length direction is fixed in the accommodating area, the other end of the crystal chip is suspended, a chip electrode is arranged at the top end of the crystal chip, and an electrode pin of the chip electrode is electrically connected with each internal electrode; the metal sealing ring is arranged at the top end of the ceramic base; the upper cover covers the top end of the metal sealing ring; and the plurality of external electrodes are arranged on the outer side wall of the ceramic base at intervals. The chip packaging structure has the advantages that external force can be effectively transmitted into the oscillation area on the chip, the chip and the packaging structure both have high force frequency coefficients, dynamic and static conditions are detected at the same time, and the high-precision effect of mechanical detection is achieved.

The invention discloses a pressure detection system, and relates to the technical field of intelligent wearing, and the pressure detection system comprises 1) a flexible substrate layer which is used for fitting skin and sensing external tiny pressure changes; the micro-column array layer is composed of a plurality of micro-column structures and used for amplifying and conducting the pressure change sensed by the flexible substrate layer; the flexible gel sensing layer is used for receiving the pressure transmitted by the micro-column array layer and generating an electric signal; 4) a packaging layer; an interdigital electrode layer is arranged in the flexible gel sensing layer, an electric signal of the flexible gel sensing layer changes along with the change of external pressure, and the detection of a pressure electric signal is realized through the interdigital electrode layer. By means of the design, high-sensitivity response to tiny pressure changes can be achieved, micro-pressure signals are remarkably amplified, meanwhile, the problem of hysteresis effect generally existing in traditional silica gel or metal film materials is solved, and therefore the response speed of the sensor is greatly increased.

The invention relates to the technical field of flexible sensing, in particular to a multi-stage pressure sensor for unconstrained monitoring and a preparation method thereof.The multi-stage pressure sensor comprises a flexible substrate, the flexible substrate comprises an upper-layer fabric and a lower-layer fabric which are arranged in a spaced mode, and the upper-layer fabric and the lower-layer fabric are connected through connecting wires; the static supporting unit comprises a plurality of supporting columns which are arranged in an array mode and fixed to the flexible substrate, and the height of the supporting columns is configured to be larger than the thickness of the flexible substrate; the flexible sensing unit is adjacently arranged on the periphery of the static supporting unit and comprises a conductive wire arranged on a flexible substrate, and the conductive wire and a connecting wire form a triboelectric sensing unit; the rigidity of the static supporting unit is larger than that of the flexible sensing unit. The purpose of the present invention is to improve response sensitivity to weak dynamic signals.

The invention discloses a hardness sensor based on pressure and strain sensor co-integration and a preparation method, and belongs to the technical field of flexible hardness sensors. The hardness sensor comprises a lower packaging layer, a lower electrode, a lower strain sensor, a lower pressure-sensitive film, an upper pressure-sensitive film, an upper strain sensor, an upper electrode and an upper packaging layer which are sequentially arranged from bottom to top. According to the invention, the pressure-sensitive film is prepared by a template method, the electrode layer is adhered to the pressure-sensitive film through the adhesive, and then the redundant pressure-sensitive film is etched by laser to obtain the pressure sensor; and the strain sensor is obtained through laser etching and chemical plating. As the space utilization rate of the pressure sensor is not high, the strain sensor is embedded into the gap of the pressure sensor, so that the pressure sensor and the strain sensor are positioned on the same plane, the space utilization rate of the device is improved, the sensitivity and the response speed of the sensor are improved, and more accurate and efficient hardness detection is realized.

Provided is a dielectric thin film including a metal oxide. The metal oxide includes bismuth, sodium, barium, and titanium, at least a part of the metal oxide is a tetragonal crystal having a perovskite structure, and a (100) plane of at least a part of the tetragonal crystal is oriented in a normal direction of a surface of the dielectric thin film.

The invention relates to a watertight differential tension and pressure sensor of a composite structure and a working method thereof, and belongs to the field of sensors, the watertight differential tension and pressure sensor comprises a force sensor on the outer side, a pressure sensor on the inner side and a watertight cable, the pressure sensor on the inner side is used for measuring water pressure, oil pressure and air pressure, and the force sensor on the outer side is used for measuring tension and pressure; the pressure sensor is embedded in the force sensor, and the contact part is sealed by welding; the pressure sensor and the force sensor are both connected with a positive wire and a negative wire, and the four wires lead out signals through a watertight cable. A brand-new core structure is adopted, the sealing performance is good, the pressure sensor and force sensor structures are arranged at the same time, the device can adapt to multiple scenes, a differential structure is adopted, and interference of the external environment is reduced.

The invention discloses a cook machine intelligent remote control method and system based on artificial intelligence analysis. The method comprises the following steps: receiving an operation instruction input by a user through remote terminal equipment; acquiring image and weight information of food materials in the chef machine by using a built-in camera and a sensor, and generating food material processing parameters based on a pre-trained neural network model; in combination with an operation instruction input by a user, the food material processing parameters and a preset recipe database, determining an adaptive stirring mode, a rotating speed and running time, and generating a control instruction; the control instruction is sent to the chef machine to be executed, the running state is monitored through a sensor, and the operation process and abnormal information are fed back in real time; and when overload, food material mixing abnormity or operation abnormity is detected, analyzing an abnormity reason and executing a corresponding adjustment strategy. According to the invention, the precision and intelligent level of food material processing can be improved, intelligent remote control and automatic optimization of the chef machine are realized, and the user experience and the stability of food material stirring are improved.

The invention discloses a thermocompression resistance PT symmetrical MEMS pressure sensor, which comprises two resonators with identical structures, and the two resonators are connected through a group of coupling spring beams. Each resonator comprises four anchor areas connected with the thin film substrate, narrow beams which are connected with the four anchor areas and have a piezoresistive effect, and a mass block connected with the four narrow beams, and the four anchor areas are symmetrically distributed on the two sides of the mass block. For one of the resonators, a current path is formed through connection of a constant current source in the anchor section on the same side of the mass block. Under the action of a constant current source, hot resistance pressing feedback is generated at narrow beams of the resonators, so that the two coupled resonators form a PT symmetric system, and the PT symmetric resonators are initially arranged at an Exception Point (EP) point. When pressure acts on the lower surface of the substrate, the substrate generates strain, the position of the anchor area is driven to change, the rigidity of the resonator is changed, a PT symmetric system deviates from an EP point, the system eigenfrequency is split and shows pull-ratio oscillation, and the frequency splitting amount depends on the pressure borne by the substrate. Because the EP point has a large response to tiny disturbance, the thermal pressure resistance PT symmetric MEMS pressure sensor can realize accurate measurement of weak pressure change, and has the advantages of high sensitivity and simple manufacturing process.

The invention discloses a tactile and temperature cooperative sensor containing a flexible substrate material and a preparation method thereof. The sensor comprises a flexible substrate, an array tactile sensing unit and a multi-layer heterostructure temperature-sensitive layer, the multi-layer heterostructure temperature-sensitive layer is formed by alternately stacking heterogeneous materials such as a pressure-sensitive material layer, a heat-sensitive material layer and a conductive material layer, and collaborative sensing of temperature and pressure can be achieved. The response performance of the sensor to various physical quantities is improved by reasonably designing the material characteristics and the interface structure of each layer. Meanwhile, the invention also discloses a corresponding preparation process, which adopts micro-nano processing technologies such as molecular beam epitaxy, chemical vapor deposition and the like to ensure the accurate construction of the multi-layer structure. The method has a wide application prospect in the fields of robot tactile perception, intelligent wearable equipment and the like.

The invention provides a resonant pressure sensor digital measurement and control circuit, which comprises a sensor core body, a first chip unit, a second chip unit, a third chip unit and a fourth chip unit, and is characterized in that the first chip unit comprises an automatic gain control module AGC, a phase-locked loop control module PLL, an SPI and an I2S, the AGC comprises an amplitude resolving module, a controller 1 and an amplitude control switch S2 which are connected in sequence; the PLL comprises a phase resolving module, a controller 2, a phase control switch S1 and a DDS which are connected in sequence; the sensor core body is respectively connected with the second chip unit and the third chip unit, the first chip unit runs embedded control software to realize sweep frequency control and AGC (Automatic Gain Control) phase-locked driving control on the core body, a control signal is obtained through digital operation, and the first chip unit controls the third chip unit to generate an analog signal as the input of the sensor core body. According to the scheme, the locking and output of the resonant frequency are realized.

The utility model relates to a torsion measuring device which comprises a wrench body and a measuring module used for measuring torsion applied to the wrench body. The torque wrench is characterized in that the measuring module is a piezoelectric resonant sensor, the piezoelectric resonant sensor is embedded in the wrench body, and the piezoelectric resonant sensor is configured to be capable of reflecting the change of torque according to the change of oscillation frequency generated by the piezoelectric resonant sensor. The device has the advantages that the piezoelectric resonant sensor serves as a measuring module, a frequency signal generated by the piezoelectric resonant sensor due to the piezoelectric or inverse piezoelectric effect can be directly used as a force sensing signal, the principle is that the oscillation frequency of the piezoelectric resonant sensor changes under the action of external force, and the frequency variation is used as a change value for judging the force of the piezoelectric resonant sensor; a frequency value can be directly detected or converted into a voltage signal, and the piezoelectric resonant sensor has the sensor characteristics of good measurement precision, sensitivity, response time, hysteresis and the like, so that the measurement precision of torsion is improved.

The invention discloses a passive gasket type pressure sensor based on parametric negative resistance self-excitation and a monitoring method, and belongs to the technical field of bolt loosening state monitoring. The sensor is improved based on a standard metal flat washer, a piezoelectric sensing unit, a pilot frequency response passive network and a passive heat-induced drift suppression circuit are embedded, and an embedding area is filled with organic silica gel. The pilot frequency response passive network uses parametric reactance to modulate nuclear strength nonlinearity to generate active negative resistance, weak radio frequency energy self-excitation is achieved, and bolt axial load change is mapped into echo frequency sideband drift; the thermally induced drift suppression circuit eliminates temperature drift. According to monitoring, the environment temperature is determined through temperature echoes, a frequency-load curve is matched, and then the bolt loosening state is determined through bolt loosening state echoes. Passive, wireless, maintenance-free and high-precision monitoring is realized, and the problems of high starting threshold, near communication, poor integration and the like in the prior art are solved.