36results about How to "Avoid chirping" patented technology

The invention relates to the optical fiber sensor technical field, disclosing a cantilever beam-type optical fiber grating accelerometer. The accelerometer comprises an outer casing used as a support structure of the accelerometer, a support column used to fix a cantilever beam, a cantilever beam, a first lug boss and a second lug boss arranged at both ends of the upside of the cantilever beam, an optical fiber grating used to measure acceleration and a mass block arranged at one end or both end of the underside of the cantilever beam, wherein one end of the support column is fixed with the cantilever beam, while the other end is fixed with the downside surface of the accelerometer; both lug bosses are used to horizontally fix the optical fiber grating and ensures a certain space between the optical fiber grating and the cantilever beam; both ends of the optical fiber grating are respectively fixed on the first lug boss and the second lug boss on the cantilever beam with one end parallel to the surface of the cantilever beam passing through the hole on the sidewall of the accelerometer to extend outside the accelerometer; and the mass block is used to adjust the sensitivity and the natural vibration frequency of the accelerometer. The cantilever beam-type optical fiber grating accelerometer increases sensitivity and improves packaging technology.

The invention discloses a fiber grating earth pressure sensor which comprises a sensor shell, a pressure transmission component and a fiber grating. The earth pressure sensor is characterized in that the pressure transmission component is of a rhombus structure, and the is positioned between a bearing-type top cover and a bottom plate, and is in contact with the bearing-type top cover and the bottom plate; clearances are arranged among the pressure transmission component and the left side and the right side of the sensor shell; a grating is pasted on a metal elastic membrane; the metal elastic membrane is arranged on a transverse diagonal line between a left angle and a right angle of the pressure transmission component; and two sides of the metal elastic membrane are fixed on the left angle and the right angle of the pressure transmission component. The earth pressure sensor provided by the invention has the characteristics of large measuring span, high accuracy and simple structure, is good for miniaturization of the integral structure.

The invention relates to a sensitivity enhancing structure of a fiber Bragg grating sensor, which is characterized in that: the invention comprises a support frame which comprises a left support arm and a right support arm which are arranged in Z-shaped structure with inverse directions one another; a fiber Bragg grating two ends of which are fixed on end parts of the left and right support arms of the support frame. The two ends of the fiber Bragg grating are fixed at lower ends of the left and right support arms of the support frame by adopting a bonding method.

The design and production of tunable dispersive compensator belongs to the fiber communications technological field. The hard core of this invention is a hit-the-toe sampling fiber raster with a twice time lag curve. The fiber raster adopts a linear chatter phasic templet production, and uses the chatter sampling period (CSP) to compensate the chatter grating period (CGP) from the templet to make the change bound of the raster sampling period narrow and then to make the producing process more simply and more steady. Otherwise in the design and producing process of the fiber raster, compensate the average refractive index change from the toe-hit by introducing the CSP. Therefore the production and toe-hit can be complete at a time in which just once exposal is needed. Finally fix the fiber raster on the exact mechanical tuning device, to extend the fiber raster under the control of microcomputer and then control the dispersive compensatory quantity.

The present invention discloses a fiber grating sensing device for detecting stress state of a water lubricated bearing and a monitoring system thereof, and solves the problems such as low success rate of fiber grating sensor implantation, short service life and high cost. The fiber grating sensing device of the invention comprises a rubber bearing composed of a plurality of rubber bearing strips;and at least one rubber bearing strip is embedded with a fiber grating sensing unit. The fiber grating sensing unit comprises a capillary axially embedded in the rubber bearing strip, optical fiber encapsulated in the capillary and filler filled between the capillary and the optical fiber. A plurality of gratings are provided on the optical fiber. The monitoring system of the invention comprisesa fiber grating sensing device, a fiber grating demodulator, a host computer, a data comprehensive analysis unit and an alarm and output unit. The invention has the advantages of easy manufacture, lowcost, good reliability, long service life, high accuracy and ability to synchronously and continuously monitoring load, temperature and stress of the bearing.

The invention relates to a torque sensor device based on fiber gratings. The device comprises the fiber gratings, an input shaft having the same axis as the fiber grating, a torsion rod and an outputshaft, wherein two ends of the torsion rod are connected with the input shaft and the output shaft through a spline, one end of the input shaft is provided with partially-annular projections symmetricto the axis, an outer circumferential surface of one end of the output shaft is provided with a groove, fiber is tensioned in a straight line mode and is tangent to the output shaft, two ends of thefiber are fixed with the partially-annular projections, the middle of the fiber is fixed on the groove, two suspended gratings are uniformly distributed among three fiber fixing points, and a tail fiber fits the surface of the input shaft, is led out along the surface of the input shaft and is then connected with a rotary connector. The device is advantaged in that a relative torsion angle is converted into stretching or compression deflection of the fiber, torque can be acquired through measuring wavelength drift amount of the fiber grating, measurement is simple and easy, anti-electromagnetic interference and temperature compensation functions are realized, sensitivity is high, and signal stability is further realized.

The invention relates to a one-dimensional palpation force sensor based on a fiber bragg grating. The sensor comprises a contact part, a force-sensitive flexible part, a fiber bragg grating and a support part, and is characterized in that the contact part, the force-sensitive flexible part and the support part are connected in sequence; the force-sensitive flexible part is formed by carrying out a configuration comprehensive design on a sarrus mechanism by adopting a rigid body replacement method, and is used for converting a contact force signal into a strain signal; the fiber bragg grating is suspended in the center of the force-sensitive flexible part under the action of a pre-tightening force, is used as a sensing element and is used for converting the strain signal into an optical signal; the contact part is provided with a hemispherical tip for concentrating a contact force at one point; and the supporting part is used for supporting and fixing the whole sensor. The force sensor has the advantages of being high in sensitivity, large in measurement range, high in linearity, high in biocompatibility, resistant to electromagnetic interference and the like, and interaction force information between a minimally invasive surgery robot and human tissue can be provided in minimally invasive surgery tissue palpation.

The invention discloses a cold and hot extension type fiber bragg grating temperature sensor which is composed of a first installation part, a second installation part and an optical fiber, the thermal expansion coefficients of the first installation part and the second installation part are different, the first installation part is provided with a notch, one end of the second installation part is fixedly connected with the first installation part, and the other end of the second installation part is provided with a boss, the boss divides the notch into two grating installation spaces, the optical fibers are provided with a first fiber grating and a second fiber grating, the first fiber grating is installed in one grating installation space, the optical fibers at the two ends of the first fiber grating are fixed to the first installation part and the boss respectively, and the second fiber grating is installed in the other grating installation space, optical fibers at the two ends of the second fiber grating are fixed to the boss and the first installation part respectively. No matter in cold or hot, one of the fiber gratings is always in a suspended stretching state, so that chirp and initial large pre-stress are effectively avoided, the sensitivity is still kept at a high level, and the temperature measurement range is also doubled.

The invention relates to a high-precision miniature torque sensor based on a fiber bragg grating, which comprises a torsion sensitive flexure structure, a fiber bragg grating and a signal processing unit, and is characterized in that the torsion sensitive flexure structure has a function of converting torsion motion into linear motion and can transmit axial displacement to an optical fiber; the fiber bragg grating is suspended on the central axis of the torsion sensitive flexure structure under the action of pretightening force, and when the torsion sensitive flexure structure rotates and generates axial displacement, the arrangement direction of the fiber is overlapped with the running direction of the linear displacement of the structure; the optical fiber can generate optical fiber strain signals which are more uniform, more sensitive and higher in linearity; the signal processing unit comprises a fiber bragg grating demodulator and a computer system and is used for converting optical signals into digital signals. The sensor disclosed by the invention has the characteristics of high sensitivity, large measurement range, high linearity, high measurement accuracy and the like.

The invention discloses a fiber bragg grating transformer winding vibration acceleration sensor and a processing method thereof, the sensor comprises a fiber bragg grating, a double-cantilever beam and a shell, and the double-cantilever beam is provided with double rectangular holes; two end points of the fiber bragg grating are fixed on the double rectangular holes of the double- cantilever beam, the fiber bragg grating is in a tightened state and located at the center line position of the rectangular holes, the fiber bragg grating is packaged in the shell along with the double-cantilever beam, and fibers of the fiber bragg grating are led out of the shell. The design of the double-cantilever beam increases directional interference resistance, and the two-point packaging design increases the sensitivity of the sensor and solves the problem of grating chirp.

The invention discloses a double-F-shaped fiber grating temperature sensor, which comprises two F-shaped structural members and an optical fiber, wherein the thermal expansion coefficients of the two F-shaped structural members are different, the two F-shaped structural members are arranged in a central symmetry manner, the middle parts of the two F-shaped structural members are fixedly connected, and a gap is formed between the head end cross beam of each F-shaped structural member and the tail end of the other F-shaped structural member. The optical fiber is provided with a first optical fiber grating and a second optical fiber grating, wherein the first optical fiber grating and the second optical fiber grating are located at the two gaps respectively, and the optical fibers on the two sides of the optical fiber gratings are fixedly connected with the head end cross beam of one F-shaped structural part and the tail end of the other F-shaped structural part respectively. The two F-shaped structural members have a large thermal expansion coefficient difference, and the relative displacement change, caused by the temperature, of the two F-shaped structural members is converted into the strain change of the fiber bragg grating, so that the sensitivity of the temperature sensor is improved. When the temperature rises and drops, the central wavelength change of one fiber grating is used for detection, and the measurement range is doubled.