149 results about "Fiber Bragg grating" patented technology

The invention discloses a ground surface settlement and ground fracture monitoring device and method based on distributed fiber sensing (DSS) and fiber bragg grating (FBG). The device comprises a GFRP composite material substrate which stretches across a ground fracture and is fixed on a stable stratum through an anchoring structure, a distributed sensing and temperature measuring optical cable which is pre-embedded in a groove of the substrate, an FBG displacement meter which is connected through a plug-and-play interface, a static force level gauge, an osmometer and other point type sensors, and the data processing unit has the functions of multi-source data acquisition, temperature compensation, data fusion and multistage early warning. According to the method, multi-parameter, distributed and high-precision monitoring of the ground fracture development state is achieved through the steps of field investigation, substrate installation, sensor deployment, system calibration, real-time monitoring and the like. The method has the advantages of high measurement precision, strong anti-interference capability, convenient installation, low cost, capability of predicting the crack propagation trend and the like, and is suitable for long-period safety monitoring of geological disaster frequent areas such as mining areas and landslide areas.

The invention relates to the crossing field of mechanical engineering and intelligent manufacturing, and discloses a real-time monitoring, regulating and controlling method for the manufacturing process of an automobile lightweight component. According to the method, a distributed fiber bragg grating sensing array is embedded in a mold, and a three-dimensional strain field at the flowing front edge of resin is obtained in real time; a multi-scale pore generation kinetic model is combined to perform online inversion on an unwetted area and pore distribution; and the pressure gradient and the mold temperature field of the hot press are adaptively regulated and controlled, and the flow path is dynamically corrected. The system comprises a sensing embedding module, a strain demodulation module, a pore inversion module, a regulation and control instruction generation module and a multi-zone execution module. According to the method, closed-loop precise control over the porosity being lower than 0.5% is achieved, and the consistency and reliability of the mechanical property of the component are remarkably improved.

The invention relates to the technical field of sensors, and discloses a decoupling method of a temperature and pressure sensor, and the sensor comprises an F-P resonant cavity and a pressure sensing diaphragm with a fiber bragg grating. The method comprises the following steps: S1, transmitting a wide spectrum signal to a sensor, and collecting a reflection spectrum of the sensor; s2, performing baseline correction and noise reduction processing on the reflection spectrum, and extracting characteristic parameters; s3, if the characteristic parameters exceed the preset range, failure early warning is carried out; establishing and substituting the characteristic parameters into a physical model, performing multi-parameter optimal estimation, and outputting temperature and static pressure; and S4, if the characteristic parameters exceed the preset range, failure early warning is carried out. In order to enable failure early warning to be more accurate, the scheme can be adjusted to monitor the characteristic parameters extracted in the step S2 in real time, and the scheme is not limited to fixed nodes. According to the invention, intrinsic decoupling is realized, the measurement precision, the decoupling efficiency and the intelligent degree are greatly improved, the practicability is high, meanwhile, the self-diagnosis function is realized, and the reliability is ensured.

The invention discloses a bolt washer sensor based on a fiber Bragg grating, which is characterized by comprising a double-layer composite washer, the double-layer composite washer comprises an inner ring and an outer ring, the inner ring is made of an FR4 epoxy resin material, and the outer ring is made of an aluminum alloy material; the strain body structures are symmetrically arranged on the two sides of the outer ring and comprise a positive strain body and a negative strain body, and the positive strain body and the negative strain body are both made of aluminum alloy materials; two fiber bragg gratings (FBG) with different central wavelengths are inscribed on the optical fiber, the two FBGs are respectively a first FBG (FBG1) and a second FBG (FBG2), the FBG1 is fixed at the central position of the positive strain body, and the FBG2 is fixed at the central position of the negative strain body. The gasket type sensor is compact in overall structure and resistant to corrosion, and has high repeatability, rapid dynamic response and long-term stability.

The invention relates to the technical field of bionic touch, in particular to a flexible touch sensor based on a filling structure and a preparation method. The flexible touch sensor comprises a flexible layer, and the flexible layer is provided with a containing groove. The liquid filling material is arranged in the accommodating groove; the sensing group is arranged on the side wall of the accommodating groove, the sensing group comprises a first fiber bragg grating and a second fiber bragg grating, and the first fiber bragg grating and the second fiber bragg grating are symmetrically arranged on the two side walls of the accommodating groove; and the packaging film is used for packaging the liquid filler and the sensing group. According to the embodiment of the invention, the miniature accommodating groove and the liquid filler are arranged on the flexible layer, so that the flexibility and the fitting property of the sensor can be improved, the fiber bragg gratings are symmetrically arranged on the accommodating groove, the lateral pressure has two opposite strains, and the temperature influence is eliminated through differential processing; and constant cooling and thermal diffusion stabilization effects on the sensing cavity in a dynamic environment can be realized.

This invention discloses an FBG strain sensor based on misaligned fusion spliced ​​coreless optical fiber and its fabrication method. The sensor comprises an input single-mode fiber, multiple segments of coreless optical fiber, and an output single-mode fiber connected sequentially. The input single-mode fiber is fused together with the first segment of the coreless fiber in a misaligned manner, and the next segment of the coreless fiber is fused together with the previous segment in a misaligned manner, with the misalignment direction of the next segment opposite to that of the previous segment, but the misalignment distance being the same. The output single-mode fiber and the last segment of the coreless fiber are fused together axially. The central axes of the input and output single-mode fibers are collinear, and the cores of the input and output single-mode fibers are connected by a photolithographically written straight waveguide. A fiber Bragg grating is then optically etched along the straight waveguide. This invention uses femtosecond lasers to fabricate the FBG on the misaligned fiber structure, increasing the structure's strain response and making the strain sensitivity of the FBG on this structure higher than that of an FBG fabricated on ordinary silica optical fiber.

This invention belongs to the field of optical experimental technology, and particularly relates to a physical experimental device and method integrating multiple fiber optic technologies. In use, the light source component emits light waves, which are reflected by the fiber Bragg grating component and split into two parts. One part of the light wave enters the filtering experimental component and then the signal processing module, which processes the signal and displays the results. The other part of the light wave enters the Mach-Zehnder interferometer experimental component and is split into a first light wave and a second light wave. The first light wave passes through the Young's modulus measurement experimental mechanism, and the second light wave passes through the fiber optic temperature sensor experimental mechanism. After exiting the Young's modulus measurement experimental mechanism and the fiber optic temperature sensor experimental mechanism, the first and second light waves couple into the signal processing module, which processes the signal and displays the results. This invention has good integration and can simultaneously measure minute displacements, mechanical parameters, and temperature.

This application discloses an optical parametric oscillator and a laser generating device, relating to the field of laser technology. The optical parametric oscillator includes a first optical fiber, a mirror assembly, a nonlinear crystal, and a second optical fiber. The first optical fiber has a first receiving end and a first output end. The first receiving end is used to receive pump light. The second optical fiber has a second receiving end and a second output end. Light output from the first output end can be transmitted to the second receiving end via the mirror assembly and the nonlinear crystal. The second output end is used to output signal light. The mirror assembly includes multiple mirrors. The nonlinear crystal is located in the optical path between two mirrors. A first grating is disposed on the first optical fiber, and a second grating is disposed on the second optical fiber. Both the first and second gratings are fiber Bragg gratings. Because this application uses a first optical fiber and a second optical fiber to define the light transmission path, compared to a free-space optical path, the optical fiber can be coiled, which is beneficial for reducing the overall size and improving integration.

The invention provides a coal body strain synchronous in-situ monitoring device and method based on true triaxial impact, and relates to the field of coal body dynamic testing and structural damage monitoring. Comprising a sample bearing module, an impact loading module, an internal fiber bragg grating dynamic strain monitoring module, a surface strain gauge monitoring module, a synchronous data acquisition module, a microscopic crack detection module and a macroscopic failure analysis module, the impact loading module is used for applying a transient impact load with a set impact speed to the gas-solid coupling coal sample, and the internal fiber bragg grating dynamic strain monitoring module is embedded with at least one fiber bragg grating sensing grating point along three mutually orthogonal directions of the gas-solid coupling coal sample respectively. The damage evolution mechanism of the gas-solid coupling coal body under the high strain rate condition is disclosed, and a means is provided for risk analysis of the rock burst-coal and gas outburst hybrid power disaster.

The invention discloses an FBG (Fiber Bragg Grating) and F-P (Fabry-Perot) cavity multiplexing air pressure sensing system, which comprises a linear tunable laser 1, a Mach-Zehnder interference device 2, a sensing array 3 and a processing unit 4, and is characterized in that an output optical coupler of the linear tunable laser 1 is connected with the Mach-Zehnder interference device 2; the linear tunable laser 1 and the Mach-Zehnder interference device 2 are directly connected with the processing unit 4, and the sensing array 3 is an FBG and F-P cavity sensor multiplexing array and is connected with the Mach-Zehnder interference device 2; according to the invention, multiplexing and distance positioning of the FBG and the F-P cavity sensor are realized, temperature compensation is carried out on pressure measurement while the spatial resolution can reach 20 [mu] m for temperature measurement, and the FBG-F-P cavity sensor can be widely applied to the fields of aviation, precision manufacturing and the like.

Optical networks and methods associated with optical networks for verifying network continuity. A method for verifying network continuity includes providing a fiber Bragg grating (FBG) device at a cable associated with a network, wherein the FBG device is configured to reflect a λ1 wavelength; sending an optical test signal into the cable from a location upstream of the FBG device, the optical test signal having a λ1 wavelength; and detecting a reflected signal associated with the λ1 wavelength to verify network connectivity to the FBG device and measure network insertion loss.

The utility model discloses a protective device for a fiber bragg grating rotating wheel strain sensor of a water-turbine generator set, which comprises a base and a waterproof cover, and a placing groove is arranged between the base and the waterproof cover for accommodating the strain sensor. The two ends of the waterproof cover are provided with optical cable holes and optical cable ends, and the adjacent optical cable holes are connected through optical cable protection tubes. The base comprises a fixed end and an inner boss, a sealing groove on the top surface of the fixed end is matched with a sealing ring, the connecting end is provided with an outer boss, the fixed end and the connecting end are connected through a fixed bolt and waterproof sealant, a sealing cavity filled with sealant is arranged in the waterproof cover, the threaded connection part of the optical cable protection tube is filled with sealant, and the waterproof cover is provided with a spiral drainage groove. The device has the advantages that the sealant is waterproof, the sensor is dry and the precision is improved; the convex surface end disperses impact force, the service life of the device is prolonged, and the protection effect of the device is improved; fixing bolts, sealants and counterbores are designed to enhance waterproofness; the spiral drainage grooves conform to water flow, and impact is reduced; the optical cable protection tube is connected in series to protect the sensor, the hose end is attached to the rotating wheel, and the tube fixing seat ensures that the optical cable is stable and well matched with the rotating wheel.

The invention belongs to the technical field of nondestructive testing, and discloses a TOFD (Time of Flight Diffraction) probe with in-situ force sensing capability and a detection system. The ultrasonic probe main body is mounted on the first carrier, and the first carrier is made of a rigid material; a second carrier is mounted on one side, far away from the ultrasonic probe main body, of the first carrier and is made of an elastic material; the second carrier comprises a contact part used for contacting a measured object, and a deformation part used for generating elastic bending in response to the stress of the contact part is fixed on one side, far away from the measured object, of the contact part; the first carrier is provided with a first fiber bragg grating used for monitoring environment temperature changes. A second fiber bragg grating is arranged on the deformation part; the problems that in the prior art, in-situ, real-time and temperature-drift-resistant contact force accurate sensing and regulation of a TOFD probe in the detection process are difficult to achieve, and the automatic detection precision and reliability are limited are effectively solved.

A Raman fiber laser includes a pump light source, a reflective end mirror, a wavelength division multiplexer, a Raman gain fiber, and an output end mirror. The output end mirror is an ultra-low reflectance fiber Bragg grating. The reflective end mirror is connected to a reflective end of the wavelength division multiplexer. The pump light source is connected to an input end of the wavelength division multiplexer. One end of the Raman gain fiber is connected to a common end of the wavelength division multiplexer, and the other end of the Raman gain fiber is connected to the ultra-low reflectance fiber Bragg grating. The laser of the present invention can reduce loss of laser light at the reflective end mirror, thereby increasing laser light optical conversion efficiency and output power, and simultaneously achieving high time domain stability and extremely low coherence.

The invention discloses a fiber bragg grating production control system and method, and belongs to the technical field of optical fiber sensor manufacturing, and the method comprises the steps: obtaining a pre-stress spectrum curve and an ultraviolet laser parameter set of a target optical fiber before writing, and constructing a feature vector reflecting the disturbance sensitivity of the optical fiber; in the laser writing process, acoustic emission signals and laser parameters are collected in real time, and a joint disturbance function is constructed; identifying a nonlinear stress disturbance event through dynamic matching with the sensitive feature vector, and extracting occurrence time and disturbance intensity of the nonlinear stress disturbance event; constructing a prediction model based on disturbance history, predicting a future disturbance trend and adjusting laser parameters; after writing, a grating reflection spectrum is collected and compared with a target template spectrum, and if the similarity requirement is not met, a disturbance error path is traced back, and parameter compensation writing is executed; according to the invention, real-time perception and response regulation and control of micro-disturbance can be realized, and the writing precision and consistency of the fiber bragg grating are improved.

A fiber amplifier to amplify seed light has a laser diode, an optical fiber segment, and a doped fiber. The laser diode generates pump light at a pump wavelength from an end facet, and optical fiber segment in optical communication with the pump light has a fiber Bragg grating (FBG) configured to lock the pump light from the end facets to the pump wavelength. The pump light from the laser diode interact with an active dopant of the doped fiber and can thereby amplifies the seed light. To provide less coherent light and improve stability of the laser diode over operation conditions, variations in refractive index in the FBG have a chirped period changing linearly along a length of the FBG. The chirped period shifts the reflectivity asymmetrically from a central wavelength region of the FBG, such as blue-shifting the reflectivity for a short wavelength.

Disclosed herein are fiber-based Raman amplifier systems and methods of generating broadband pump light using a fiber Bragg grating (FBG) including a plurality of gratings. In the disclosed system and method, each of the plurality of gratings includes a central wavelength ([lambda] C) corresponding to a wavelength of an output from a laser, respectively, where the central wavelengths ([lambda] C) of at least two gratings of the plurality of gratings are different from each other. Further disclosed are systems and methods of using a pump source, where the pump source includes a plurality of the lasers that are optically connected to a plurality of the FBGs, respectively, where at least two of the FBGs have the same FBG design as a plurality of the gratings.

An optical fiber having an acoustic sensitive fiber bragg grating includes an optical fiber core having a pair of fiber bragg gratings formed therein such that each fiber bragg grating is spaced apart from each other. A cladding material is disposed on and surrounds at least a portion of the fiber core. The cladding material has at least one material characteristic associated therewith, where the at least one material characteristic may be a Young's modulus less than a Young's modulus of the fiber core, a photoelastic coefficient greater than a photoelastic coefficient of the fiber core, or a combination thereof. The ultrasonic sensor includes at least one optical fiber embedded in a polymer layer and a backing layer and an acoustic matching layer.

The application relates to a method of an electric field sensor based on an optoelectronic oscillator, belonging to the field of optical devices and optical fiber sensing. The device comprises a laser source, a polarization controller, a phase modulator, a fiber Bragg grating with an acrylate glue cavity, a stacked piezoelectric ceramic, an electric field generator, an erbium-doped fiber amplifier, a photodetector, a power divider and an electric amplifier. The stacked piezoelectric ceramic is combined with the fiber Bragg grating with the acrylate glue cavity as a sensing head, the wavelength change of the fiber Bragg grating with the acrylate glue cavity caused by the piezoelectric effect is mapped to the frequency change of the microwave signal generated by the optoelectronic oscillator, and the electric field change value can be obtained by monitoring the microwave signal of the optoelectronic oscillator. In the loop of the optoelectronic oscillator, the electric spectrum analysis technology is used for demodulation, and high-speed and high-resolution electric field measurement can be obtained. The method has the advantages of simple structure, high measurement sensitivity and easy practicability.

This invention relates to the field of fiber optic sensing technology, specifically to a high-resolution, high-capacity fiber optic quasi-distributed sensing system and demodulation method. The system includes: an optical emission and pulse modulation module that emits narrowband laser light at a set step size, performs pulse chopping and optical amplification, and outputs optical pulses; an optical transmission and amplification module that isolates the reflected light, and guides the amplified optical pulses into a non-identical weak fiber Bragg grating array, extracting the signal light reflected from the array; within the same partition of the non-identical weak fiber Bragg grating array, signals are transmitted using wavelength division multiplexing (WDM), while between different partitions, signals are transmitted using time division multiplexing (TDM); a photoelectric conversion and data acquisition module converts the reflected optical signal into an electrical signal, performs A / D sampling and synchronous acquisition on the electrical signal; and a control processing module sends a synchronous control signal, performs time-domain signal filtering, spectral sliding filtering, and peak-finding demodulation on the acquired signal, and inverts the wavelength information of each weak fiber Bragg grating. This solves the problems of high transmission loss and low reliability in existing technologies.

The invention discloses a time delay reserve pool calculation method based on dispersion orthogonal polarized light feedback VCSEL. An adopted time delay RC system comprises a tunable laser, a Mach-Zehnder modulator, a VCSEL, an optical isolator, an optical coupler, a polarization controller, a variable optical attenuator, a chirp fiber Bragg grating and a photoelectric detector. A signal of the input layer is modulated by a Mach-Zehnder modulator and then is injected into an X polarization component of the VCSEL of the reserve pool layer; emitted light of the VCSEL is divided into two paths after passing through the optical circulator, one path is reflected back to the VCSEL by the chirp fiber bragg grating after being subjected to cross-polarization rotation through the polarization controller, and a reserve pool layer of the time delay RC system is constructed; one path is transmitted to the output layer and is converted into an electric signal through a photoelectric detector. According to the method, the time delay characteristic can be further inhibited, so that generation of harmful resonance is further inhibited, and the method has stronger nonlinear characteristic and better calculation performance.

The invention relates to the technical field of bionic touch, in particular to a negative Poisson's ratio-based flexible touch sensor and a preparation method thereof. The flexible tactile sensor comprises a flexible layer, a first electrode, a second electrode, a third electrode, a fourth electrode, a fifth electrode and a sixth electrode, the negative Poisson's ratio microstructure is arranged in the sensing area; the sensing group is arranged on the flexible layer, the sensing group comprises a first fiber bragg grating and a second fiber bragg grating, and the first fiber bragg grating and the second fiber bragg grating are symmetrically arranged on the negative Poisson's ratio microstructure and used for obtaining two opposite strains under the same acting force. According to the embodiment of the invention, the lateral pressure is coupled to the axial direction by arranging the negative Poisson's ratio microstructure and is amplified, and the differential value is obtained by arranging the two symmetrically arranged fiber bragg gratings, obtaining two strains with opposite symbols and calculating the strain difference, so that the temperature compensation is obtained, that is, the temperature cross sensitivity is reduced; and the tactile sensitivity is improved.

The invention belongs to the technical field of distributed optical fiber sensing, and relates to an anti-distortion distributed optical fiber sensing method and system based on array phase spectrum demodulation, an ultra-weak reflection optical fiber Bragg grating array is used as a sensing optical fiber, a series of reflection peaks with the signal-to-noise ratio higher than that of RBS are generated, a reflection peak sequence is formed, and the beat frequency signal spectrum amplitude is increased. A discrete beat frequency signal with frequency domain distortion output by an OFDR sensing system is converted to a frequency domain through Fourier transform of a symmetric window function to obtain a corresponding discrete frequency spectrum, and characteristic parameters such as amplitude and phase of a reflection peak sequence in the frequency spectrum are tracked and extracted; and then frequency correction factors of the reflection peak sequence in all measurement periods are calculated by using an amplitude interpolation correction method to obtain a corrected accurate array phase spectrum, and phase difference and strain calculation are performed to realize multi-point quasi-distributed strain demodulation for suppressing frequency domain distortion such as Doppler frequency shift and the like. The frequency resolution limitation caused by the fence effect is broken, and the fidelity of the frequency domain distortion signal is recovered.

The invention provides an optical fiber shape sensing system, method, medium and equipment, in the system, a sensing unit comprises a multi-core optical fiber, the multi-core optical fiber is provided with at least three eccentrically distributed sensing cores and a central core, each sensing core is inscribed with a fiber bragg grating used for sensing axial strain caused by bending and torsion, and the central core is provided with a fiber bragg grating used for sensing the axial strain caused by bending and torsion. The central core is used for providing temperature compensation reference; the signal processing unit is used for receiving the original wavelength and strain data acquired by the sensing unit and executing filtering, temperature compensation and curvature and torsion calculation processing; and the shape reconstruction and display unit reconstructs a three-dimensional space curve through numerical integration based on the geometric parameters output by the signal processing unit, and realizes real-time visual display of a three-dimensional shape. According to the invention, high-precision and high-stability optical fiber shape sensing can be realized in a complex dynamic scene, and application requirements of complex scenes such as medical catheter navigation and flexible robot control can be met.

This invention relates to a measurement and sensing device suitable for tactile ultrasonic phased arrays, comprising: a mechanical measurement and sensing module, a fiber Bragg grating array; an acoustic measurement and sensing module, located coaxially below the fiber Bragg grating array; and a sensor structure housing that accommodates the aforementioned mechanical measurement and sensing modules and the acoustic measurement and sensing module.

The invention discloses a fiber bragg grating tactile sensing device and method. The device comprises a signal acquisition module which is used for acquiring a strain signal on the surface of the flexible photosensitive resin and converting the strain signal into a digital signal; the signal processing module is connected with the signal acquisition module and is used for carrying out wavelength analysis on the digital signals and extracting strain characteristics; and the output module is connected with the signal processing module and is used for outputting the strain characteristics in an image or defect alarm form so as to finish sensing the surface of the flexible photosensitive resin. According to the device, high-sensitivity, high-stability and visual sensing of the micro strain on the surface of the flexible photosensitive resin is realized by constructing a sensing system of signal acquisition, signal processing and output presentation.

In surgical systems, the endoscope can extend distally toward the target site. A sensing optical fiber extending distally to the endoscope may include a fiber Bragg grating positioned at the distal end of the sensing optical fiber. A sensing controller can guide the sensing light distally along the sensing optical fiber so that at least a portion of the sensing light is reflected as reflected light from the fiber Bragg grating. The sensing controller can perform optical frequency domain reflectance measurements on the reflected light to determine parameter values, such as pressure or temperature, at the fiber Bragg grating. A processing circuit can analyze the parameter values ​​to determine if specified conditions are met, such as excessively high pressure or temperature at the target site, and respond by generating a warning data signal or performing an appropriate task.

The provided is a torsion compensation system and a compensation method for a FBG curvature sensor. The compensation system includes a FBG curvature sensor, installed on a scraper conveyor; angle sensors, including two and installed on both sides of the FBG curvature sensor, are configured to obtain the torsion angle of the FBG curvature sensor by monitoring the difference between the two ends of the FBG curvature sensor; a FBG string, arranged on the FBG curvature sensor to form a plurality of grating measuring points, is configured to perceive the center wavelength of the FBG curvature sensor; a FBG demodulator, coupled with the FBG string, is configured to convert the optical signal of the center wavelength perceived by the FBG string into an electrical signal; a computer, respectively coupled with the angle sensors and the FBG demodulator, is configured to eliminate the FBG wavelength variation caused by torsion.

Disclosed herein a sensor, a sensor system and a method of sensing. The sensor, comprises: a multilayer base defining a thickness axis, the multilayer base comprising: a substrate layer; a sensing layer coupled to the substrate layer, the substrate layer being more rigid than the sensing layer; at least one Fiber Bragg Grating (FBG) embedded in the sensing layer, wherein the substrate layer and the sensing layer are collectively bendable relative to a neutral plane, wherein the at least one FBG is spaced apart from the neutral plane along the thickness axis, and a plurality of projections coupled to a sensing surface of the sensing layer and adjacent to the at least one FBG, wherein the plurality of projections defines at least one contact region on the sensing surface.

The invention discloses a double-fiber Bragg grating strain sensor based on a flexible hinge and a test method, and the sensor is installed in a sealing barrel, and comprises a first transverse supporting arm and a second transverse supporting arm which are parallel to each other; the second transverse supporting arm is arranged right above the first transverse supporting arm; the first end part of the second transverse supporting arm is a free end, and the second end part of the second transverse supporting arm is connected with the first end of the first flexible hinge; the second end part of the first flexible hinge is connected with the upper end of the rectangular metal sheet, and the lower end of the rectangular metal sheet is fixed on the support frame; the supporting frame is arranged at the top of the inner side of the sealing barrel; the first end of the first transverse supporting arm is connected with the first end of the second flexible hinge, and the second end of the second flexible hinge is fixed to the supporting frame. The second end of the first transverse supporting arm is connected with the first end of the elastic strain unit, and the second end of the elastic strain unit is connected with the second transverse supporting arm.