32results about How to "Eliminates temperature drift" patented technology

The invention discloses a current sensing circuit which comprises a Wheatstone bridge circuit and a negative feedback circuit. The Wheatstone bridge circuit is provided with at least four connected magnetoresistive elements and a pair of output ends. The magnetoresistive elements are used for sensing an external magnetic field with a first direction generated by a carrier electric conductor and outputting a differential signal. The negative feedback circuit is connected with the output ends, is driven by the differential signal and generates a magnetic field with a second direction opposite to the first direction, so that the influence of magnetoresistive element properties by temperature drift is eliminated. The temperature drift generated by the circuit under variable environments can be eliminated, and accurate voltage output is obtained.

A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

The invention discloses a fluid conductivity sensor, and a device and a method for measuring fluid conductivity, and relates to the field of wireline logging. The method comprises the following steps: detecting voltage values of the two ends of a receiving resistor at different temperatures when no fluid passes to obtain multiple groups of first voltage values; inverting a relationship between induced voltages generated at the two ends of the receiving resistor by a transmitting coil and temperature variation according to the relationship between the multiple groups of first voltage values and temperature variation; detecting the voltage values of the two ends of the receiving resistor at different temperatures when fluid to be monitored passes to obtain multiple groups of second voltage values; calculating to obtain a relationship between the fluid conductivity and temperature variation according to the relationship between the induced voltages generated at the two ends of the receiving resistor by the transmitting coil and temperature variation and the multiple groups of second voltage values. Due to the design that a winding is connected in parallel with the fluid conductivity sensor and a matched circuit is provided, temperature compensation of the sensor is realized, and measuring accuracy of the coil type fluid conductivity sensor under a high-temperature environment is guaranteed.

The invention discloses a method and a device of heterodyne interferometry of incident light and laser at opposite angles based on a rectangular prism, and belongs to the technical field of laser application. The method adopts two beams of spatial isolation parallel light with different frequencies, incidence points of the two parallel beams on a non-polarization splitting prism are located on a diagonal of an incidence surface and are symmetrical about a central point of the incidence surface, and the rectangular prism is taken as a reference prism and a measuring prism; interferometry is carried out by generating two interferometry signals with opposite Doppler frequency shifts finally. According to the method and the device, the frequency aliasing phenomenon in an interferometer can be eliminated, the measuring precision of heterodyne interferometry is improved, and meanwhile, the resolution of heterodyne interferometry is doubled.

The invention discloses a resonant system for a bidirectional light carrying microwave based on a circulator structure and a method for detecting an angular velocity thereof. According to the resonantsystem for the bidirectional light carrying microwave based on the circulator structure and the method for detecting the angular velocity thereof, a high-stability light carrying microwave of which polarization states in a forward and reverse direction are perpendicular is generated in an optical fiber ring by utilizing a regenerative mold locking technology, a cavity length control technology and a polarization state separation technology, and the light carrying microwave is used for measuring the rotation angular velocity. The circulator structure is adopted and the resonance of the bidirectional light carrying microwave is realized through a bidirectional regeneration mode locking technology. A reciprocal resonant system for the bidirectional light carrying microwave is achieved basedon a non-reciprocal error elimination technology of a wide-spectrum optical interferometer. The polarization state separation technology is adopted to achieve dual-wavelength separation of optical signals and the vertical polarization state is adopted for opposite transmission in a sensitive ring, so that the detection capability of the sensitive ring is improved. The cavity length control technology is adopted to lock the oscillation frequency of the microwave in one direction to a high-stability standard-time reference source, so that a relative cavity length of the optical resonant cavity is stabilized. The system and the method have the characteristics of high practicability, high measurement precision and the like.

The invention discloses an electronic load precise dual-temperature correction method. The method includes the steps of obtaining a referential correction value under the current environment temperature, conducting correction on a tensile load value obtained through measurement under the current environment temperature according to the referential correction value so that the influence on factors such as temperature drifting of circuit components can be eliminated, thereby obtaining an actual tensile load value under the current environment temperature, conducting comparison operation through the actual tensile load value under the current environment temperature and a set value which is stored in a calculating and processing unit in advance, and obtaining a precise correction value, and outputting the precise correction value to a tensile load circuit so that the tensile load value in the tensile load circuit can be changed and the tensile load value in the tensile load circuit can be accurately corrected. The invention further discloses an electronic load precise dual-temperature correction circuit.

A calibration method includes forming an external optical path, forming an internal optical path, and conducting a phase comparison between the second part of signals of the internal and external optical paths sequentially received by a second receiving device and the first part of signals of the internal and external optical paths sequentially received by a first receiving device. Two-way phase signals are outputted with part of a base reference being eliminated. Phase comparison is conducted again between the two-way signals with part of the base reference being eliminated, and the final phase signal is outputted with the base reference being eliminated. The distance-measuring device includes a transmitting device, first reflective surface, first and second receiving devices, first and second filters, and a phase detector. This realizes phase compensation and calibration, avoids introducing uncertain phase noise into a circuit due to environmental changes, improves distance-measurement precision, and reduces system costs.

The invention discloses a method for eliminating temperature drift of a cylindrical shell gyro by utilizing a dual-node electrode. The method comprises the following steps: (1) setting a piezoelectric electrode positioned at a detection node position as two electrodes, and forming the dual-node electrode, wherein the two electrodes are positioned on two sides of a detection rigid shaft and form a small included angle with the detection rigid shaft, and the included angle between the two electrodes is recorded as Delta theta; (2) measuring electrode signals Vds, Vn1 and Vn2 of the gyro in the absence of angular velocity input, and calculating the Delta theta; and (3) calculating the angular velocity, namely performing demodulation and low-pass filtering on the signals of the dual-node electrode, and calculating the angular velocity according to the filtered signals. The method disclosed by the invention has the advantages of simple principle, simplicity in implementation and low implementation cost.

The invention discloses a high-sensitivity fiber Bragg grating strain sensor based on flexible hinges. The high-sensitivity fiber Bragg grating strain sensor comprises an elastic strain substrate and a fiber Bragg grating cluster, wherein the elastic strain substrate comprises a transverse beam, an elastic strain unit, a fixed end and displacement amplification mechanisms; two ends of the transverse beam are connected with the fixed end through the elastic strain unit respectively, so that a temperature compensation mechanism is formed; the displacement amplification mechanisms are symmetrically distributed at upper and lower sides of the transverse beam along the transverse axis; the fiber Bragg grating cluster comprises a strain measurement grating and a temperature compensation grating; the strain measurement grating is located at a longitudinal axis position of the elastic strain substrate and is mounted on two longitudinal displacement arms; two ends of the temperature compensation grating are located at a transverse axis position of the elastic strain substrate and the temperature compensation grating is mounted on the transverse beam. The high-sensitivity fiber Bragg grating strain sensor based on the flexible hinges has the advantages of great strain sensitivity, simple and small structure, high reliability, easiness of being mounted and capability of effectively eliminating temperature drift, and is suitable for high-precision strain measurement of a small measurement range in all mechanical structures.

The invention discloses a system and a method for improving temperature stability of a scale factor of a silicon micro gyroscope. The system comprises a driving closed loop, a detection closed loop and a scale factor temperature compensation module; the driving closed loop produces driving mode resonant frequency omegax of the silicon micro gyroscope and a sine signal sinomegaxt of the omegax, andthe omegax and the sinomegaxt are respectively output to a scale factor temperature compensation module and the detection closed loop; the detection closed loop produces an angular velocity signal without scale factor temperature compensation, and the angular velocity signal is input into the scale factor temperature compensation module; the scale factor temperature compensation module performs scale factor temperature compensation on the angular velocity signal without scale factor temperature compensation based on omegax, and produces a compensated angular velocity output signal; and the compensated angular velocity output signal has no connection with the omegax. Through the system and method disclosed by the invention, the scale factor temperature compensation is realized based on a gyroscope force feedback closed-loop detection mode, and the temperature stability of the scale factor of the gyroscope can be improved.