135 results about "Magnetoresistive sensor" patented technology

The invention provides a fault positioning method and system for an overhead line of a power distribution network, and a storage medium. The method comprises the steps of obtaining a plurality of fault traveling wave magnetic field signals; performing the following steps on any signal: performing phase-mode transformation on the signal, extracting and decomposing a line mode component, determining a modulus maximum point, and determining the time corresponding to the point as a first fault traveling wave head arrival moment; carrying out clock synchronization on the moment, and obtaining a wave head arrival moment of a second fault traveling wave; obtaining a to-be-detected fault point and a line parameter; based on the wave head arrival moments of the plurality of second fault traveling waves, extracting a head end arrival moment and a tail end arrival moment; and performing fault positioning on the overhead line of the power distribution network based on the head end arrival time, the tail end arrival time and the fault line parameters. According to the fault positioning method for the overhead line of the power distribution network, interference to normal operation of the power distribution network can be avoided, and high-precision non-intrusive positioning of the overhead line of the power distribution network is realized through the tunneling magnetoresistive sensor.

The invention relates to a current measurement method and device, computer equipment, a storage medium and a program product. The method comprises the following steps: acquiring the magnetic field intensity of the two sides of a monitoring point at the current moment through a first magnetoresistive sensor and a second magnetoresistive sensor which are deployed on the two sides of the same monitoring point of a power transmission line to obtain first magnetic induction intensity and second magnetic induction intensity; wherein the first magnetoresistive sensor and the second magnetoresistive sensor are located in the same electromagnetic environment; according to the first magnetic induction intensity, the second magnetic induction intensity and the error coefficient of the first magnetoresistive sensor and the second magnetoresistive sensor, the initial current value of the monitoring point at the current moment is determined, and the influence of the hysteresis effect on the current value is eliminated; and Kalman filtering processing is carried out on the initial current value of the monitoring point at the current moment to obtain the target current value of the monitoring point at the current moment, so that the accuracy of the measured current value is further improved.

A point-of-care device and method for simultaneously and quantitatively assessing a magnetically-labelled analyte immobilised on a lateral flow test strip are provided. The method comprises the steps of sensing a magnetic signal from the magnetically-labelled analyte on the test strip and converting the magnetic signal into an electric signal; processing the electric signal to obtain a quantitative value of the amount of analyte; and processing the values to provide a differential assessment between the magnetically-labelled analyte. The device includes a magnetic reader with at least one magnetic sensor, such as a giant magnetoresistive sensor. The magnetic sensor can be directly or indirectly coupled to a lock-in amplifier configured to perform phase-sensitive detection and enhance the signal-to-noise ratio of weak magnetic signals. A system, microfluidics device, lateral flow immunoassay test strip and kit are also provided.

The invention discloses a low-noise, high-precision and low-power-consumption tunnel magnetoresistance array type magnetic anomaly detection device, and relates to the field of geomagnetic field magnetic anomaly detection. In order to overcome the defects that in the prior art, the detection precision is insufficient, the noise level is high, power consumption is large, and long-time stable operation is difficult to consider, the technical scheme provided by the invention is that a signal acquisition and amplification circuit is composed of a plurality of triaxial tunnel magnetoresistive sensors, an isolation circuit, an instrument amplification circuit and a passive filter circuit; the master control and signal processing circuit is composed of a high-precision analog-to-digital conversion circuit, a clock circuit and a microprocessor circuit. The signal transmission circuit is composed of an Ethernet module and is used for transmitting the processed data to an upper computer; the power supply module is composed of a low-noise low-dropout voltage stabilizing circuit and a reference voltage circuit, and is used for providing a stable power supply and a unified reference voltage. The method is suitable for long-time high-precision geomagnetic anomaly detection work in geophysical exploration, national defense safety monitoring and complex environments.

The invention discloses a current sensor structure based on tunnel junction magnetoresistance and a manufacturing method, the current sensor structure comprises a first array group and a second array group, and the first array group and the second array group are composed of a first tunnel junction magnetoresistance array unit and a second tunnel junction magnetoresistance array unit which are arranged along the same sensing direction, and a first electrode unit and a second electrode unit; the sensitive axis directions of the first array group and the second array group are opposite to each other, and the second array group rotates by 180 degrees relative to the first array group in the physical space and then is in cross connection through metal electrodes. The tunnel junction magnetoresistive sensor has the beneficial effects that the tunnel junction magnetoresistive sensor comprises the first array group and the second array group, and the first tunnel junction magnetoresistive array unit and the second tunnel junction magnetoresistive array unit in the first array group and the second array group respectively comprise eight arrays, so that the tunnel junction magnetoresistive sensor has higher physical reliability and stability; the measurement error of the tunnel junction magnetoresistive sensor caused by the magnetic field gradient can be reduced; when the magnetic field and the current are measured, the magnetic field with the magnitude as low as 17 nT / Hz can be measured.

The invention provides an implantable medical device and a positioning method of a wireless energy transmission coil thereof, and the method comprises the steps: re-exciting a magnetic field through a transmitting coil in a process that the spatial position of the transmitting coil is adjusted; acquiring an induced electrical signal at the receiving coil corresponding to the process of re-exciting the magnetic field; and extracting slope characteristics from the acquired induction electric signals, and judging whether the receiving coil is aligned with the transmitting coil or not according to the slope characteristics. Sensors (such as a magnetoresistive sensor and an electronic compass) hardware do not need to be additionally arranged, the size of the implantation end is small, trauma to a patient in the implantation process is reduced, the coil alignment state is judged by extracting slope characteristics instead of judging the coil alignment state based on signal intensity (such as an absolute value of induced voltage), and the accuracy of the coil alignment state is improved. The judgment method based on the slope characteristics is higher in accuracy and better in anti-interference performance.

The application provides a full-bridge magnetoresistance sensor and an electronic device. The circuit structure of the full-bridge magnetoresistance sensor is a full-bridge circuit structure, and the long axis directions of each sensing unit on adjacent bridge arms in the full-bridge circuit structure are parallel. The sensing unit comprises a flip function layer, a dielectric layer and a magnetoresistance thin film arranged from bottom to top. The flip function layers of the sensing units on two parallel bridge arms are connected to the same current input end, and the flip function layers of the sensing units on the other two parallel bridge arms are connected to the same ground end. By applying a single current to the current input end, the current flowing through the flip function layers of the adjacent bridge arms is opposite, so that the pinning direction of the anti-ferromagnetic layer of the sensing unit in which the heat generated by the flip function layer and the local magnetic field are reversed is opposite, and then the magnetization direction of the reference layer in the sensing unit on the adjacent bridge arm is opposite, so that a complete full-bridge structure is realized on a single chip, and the effect of flexibly setting or resetting the reference layer direction after production or during use can be achieved.

The invention relates to the technical field of steel wire rope defect detection, and discloses a high-precision steel wire rope defect detection device and a detection method thereof.The high-precision steel wire rope defect detection device comprises a broken wire gathering detection cover, a detection ring is installed on the outer wall of the broken wire gathering detection cover, and a pressure sensor is fixedly arranged on the inner wall of the side, close to the broken wire gathering detection cover, of the detection ring; a plurality of supporting assemblies are installed on the inner wall of the side, close to the pressure sensor, of the detection ring, each supporting assembly comprises a first sliding plate, a rubber wheel body is rotationally connected into the first sliding plate, an infrared distance meter is installed on the upper surface of the first sliding plate, and a plurality of magnetoresistive sensors are fixedly arranged on the inner wall of the detection ring. According to the invention, through dual recheck of a sensor detection activation video, real-time and accurate monitoring of defects such as wire breakage and abrasion of the steel wire rope is realized, the problems of strong subjectivity, low efficiency, easy missing hidden dangers and the like existing in a traditional manual visual or offline detection means are overcome, and the effects of operation safety and maintenance scientificity of the steel wire rope are remarkably improved.

Techniques described herein involve an electronics-free downhole flow sensor. For example, a system can include a receiver positioned at a surface of a wellbore. A flow sensor can be positioned downhole in the wellbore. The flow sensor can include a wire positioned within a flow path of downhole fluid in the wellbore. The wire can oscillate based on flow of the downhole fluid. The flow sensor can also include a variable reluctance sensor that can detect an electrical signal that is generated by oscillation of the wire. The variable reluctance sensor can transmit the electrical signal to the receiver. The receiver may determine a resonant frequency based on the electrical signal and may determine a fluid velocity of the downhole fluid based on the resonant frequency.

A method of measuring a rotational position of an assembly having circumferential ferromagnetic teeth includes applying (1302) a periodic excitation signal to an actuator, the periodicity causing a first rotational displacement of a first ferromagnetic tooth from a first rotational position to a second rotational position and a second rotational displacement of a second ferromagnetic tooth from the second rotational position to a third rotational position. The method also includes measuring (1303) a plurality of first signal outputs from a magnetoresistive sensor during the periodicity; determining one or more signal offset values based on the plurality of first signal outputs; applying the excitation signal to the actuator for a portion of a second periodicity; measuring a second signal output from the magnetoresistive sensor; generating (1304) a corrected signal by modifying the second signal output with the signal offset values; and determining (1305) the rotational position of the assembly based on the corrected signal.

This application provides a full-bridge magnetoresistive sensor and electronic device. The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure, in which the long axis directions of the sensing units on adjacent bridge arms are parallel. The sensing unit includes: a flip-flop functional layer, a dielectric layer, and a magnetoresistive thin film arranged from bottom to top; the flip-flop functional layers of the sensing units on two parallel bridge arms are connected to the same current input terminal, and the flip-flop functional layers of the sensing units on the other two parallel bridge arms are connected to the same ground terminal; by applying a single current to the current input terminal, the current flowing through the flip-flop functional layers of adjacent bridge arms flows in opposite directions, so that the heat generated by the flip-flop functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit with local magnetic field reversal are opposite, thereby making the magnetization direction of the reference layer in the sensing unit of adjacent bridge arms opposite, thus realizing a complete full-bridge structure on a single chip, and achieving the effect of flexibly setting or resetting the direction of the reference layer after manufacturing or during use.

A biomagnetic sensor that incorporates an integrated active noise cancellation unit that uses a gradiometer to remove ambient magnetic noise from a detection signal obtained from a tunnelling magnetoresistive (TMR) sensor unit that is indicative of a magnetic field adjacent to biological tissue. The ambient magnetic noise can thus be removed in real time at a front end of the sensor (e.g. as part of circuitry in the sensor body itself). The active noise cancellation technique proposed herein may be effective enough to enable the biomagnetic sensor to be used in an unshielded environment (i.e. an environment that is subject to the Earth's magnetic field, for example), which widens significantly the potential uses for the sensor.

The invention discloses a hand-assisted control method for a side-opening door of an electric vehicle. The hand-assisted control method is suitable for an electric side-opening door or a vertical hinged door of the vehicle. The system comprises a driving motor, a high-resolution magnetic resistance sensor and a controller, and the magnetic resistance sensor is installed at the tail end of an output shaft of a motor rotor, right faces a radial magnetizing permanent magnet and outputs angle signals in real time; the vehicle door opening and closing angle d is calculated through the controller on the basis of the signal and the reduction ratio, and the angular speed W is calculated through the second-order central difference method at the sampling frequency larger than or equal to 8 kHz; when Wgt; when W0 is larger than or equal to delta t and the duration time is larger than or equal to delta t, the motion direction is judged according to a W symbol, and target torque is generated according to a segmented power-assisted curve: the middle stroke T1 is in direct proportion to W, the tail stroke (d is smaller than or equal to 0.1 dmax or d is larger than or equal to 0.9 dmax) T1 is linearly attenuated to zero, reverse damping torque in direct proportion to W is superposed to achieve buffering, and when Wlt is larger than or equal to delta t within 50-100 continuous periods, Wt is larger than or equal to delta t within 50-100 continuous periods; when Wmin is detected, static is judged and power assisting is stopped, IMU is not needed, the structure is simplified, response is sensitive, operation is stable and quiet, and the user experience is remarkably improved.

The utility model discloses a magnetoresistive sensor with a conductive slip ring and a measurement experiment instrument of a geomagnetic field, which comprises a fixed working plate with an angle, a limiting ring is fixed on the lower wall surface of the working plate, a locking nut is arranged on the limiting ring, a fastening jackscrew is arranged on the locking nut, a ring groove is arranged on the working plate, and the conductive slip ring is arranged in the ring groove. A ring groove is formed in the working plate, a rotating steel ball is installed in the ring groove, a coil rotating table is installed in the working plate, and the coil rotating table is in lap joint with the rotating steel ball. A magnetoresistive sensor with a conductive slip ring and an experimental instrument for measuring a geomagnetic field are suitable for one of experimental instruments for measuring a weak magnetic field in an electromagnetic physical experiment of higher hospital science, and a precise angle measuring device of the instrument adopts the conductive slip ring, so that the instrument can rotate by 360 degrees without hindrance during angle measurement, and a measuring wire is not cut off; and the measurement is more convenient.

The invention provides a rotor turn-to-turn short circuit monitoring system and method based on a tunnel magnetoresistive sensor array, and the system achieves the axial positioning of a rotor turn-to-turn short circuit fault point through the axial arrangement of a plurality of magnetic field sensors at the opposite positions of the same rotor groove, and comparing the differences of the magnetic field waveforms corresponding to the magnetic field sensors. The fault positioning precision is greatly improved, and key guidance information is provided for maintenance. The array arrangement of the magnetic field sensors provides magnetic field sampling points with high spatial resolution, and a plurality of fault points in a short distance can be distinguished. In addition, the magnetic field intensity is directly measured instead of the change rate, signals are more stable, and the influence of rotating speed fluctuation is small.

In implementations described herein, processes, methods, and techniques are described for the detection of analytes in a sample using multiplexing methods for giant magnetoresistance sensors.

A biomagnetic field sensor for detecting magnetic fields from the human body comprises: a tunnelling magnetoresistive (TMR) sensor unit 104 to measure a biological magnetic field; a gradiometer unit 1

The application relates to a current detection method and device, computer equipment and a storage medium. The method comprises the following steps: determining an initial current of a conductor to be detected according to an initial magnetic induction intensity detected by at least one basic magnetic resistance sensor; controlling opening and closing of the at least one basic magnetic resistance sensor and at least one bias magnetic resistance sensor according to the initial current; and detecting a target current of the conductor to be detected through the magnetic resistance sensor in the opening state. The method can detect the predicted current of the conductor to be detected through the basic magnetic resistance sensor and the bias magnetic resistance sensor, then control opening and closing of the basic magnetic resistance sensor and the bias magnetic resistance sensor, and detect the target current according to the adjusted current detection equipment, thereby improving the accuracy of current detection.

A magnetoresistive sensor with harmonically broadened linear range comprises a substrate (100) and a multiple push-pull magnetoresistive sensing bridge arms. The push arms (91) of the sensing bridge comprise N types of push magnetoresistive sensing units (94). The pull arms (92) comprise N types of pull magnetoresistive sensing units. Key characteristic parameters of each magnetoresistive sensing unit comprise R0i, MRi, Hsi, ±αpi and ai. The Key characteristic parameters of the push magnetoresistive sensing units (94) and corresponding pull magnetoresistive sensing units are different from the key characteristic parameters of standard magnetoresistive sensing unit of a standard push-pull linear magnetoresistive sensor. There is at least one set of key characteristic parameters [(R0j, MRj, Hsj, ±αpj), aj]. Linear parts and nonlinear harmonic parts of R-H characteristic parameters that characterize the push magnetoresistive sensing units and the pull magnetoresistive sensing units are superimposed, so that the linear range of the multiple push-push magnetoresistive sensing bridge is greater than the linear range of the standard push-pull linear magnetoresistive sensor.

The invention relates to the technical field of wireless charging, in particular to a wireless charging accurate positioning method based on a tunnel magnetoresistive sensor, which comprises the following steps: constructing a wireless charging positioning system; the magnetic induction intensity in the z direction is pre-measured through the TMR sensor, and the mapping relation between the magnetic induction intensity and the transverse offset distance is fitted according to the relation between the magnetic induction intensity and the transverse offset distance; solving a linear solution by using a three-point positioning method to obtain a preliminary positioning value; the problems that existing magnetic sensors need to be densely arranged, two-dimensional plane full coverage is difficult to achieve, cost is high, and positioning precision is low are solved.

The invention relates to a magnetoresistive sensor (500). A magnetoresistive sensor (500) includes a layer stack (510) having at least one reference layer (512) having a reference magnetization perpendicular to a plane of the layer stack and at least one free layer (516) having a vortex magnetization. The magnetoresistive sensor (500) further comprises at least one soft magnetic shield (520) arranged adjacent to the layer stack, which soft magnetic shield is designed to reduce the influence of an external magnetic field on the free layer (516) along the shield axis (530).

The application belongs to the technical field of biosensing, and particularly relates to a giant magnetoresistance biosensor for detecting protease, a preparation method and application thereof, which comprises a giant magnetoresistance sensor, a glass sheet plated with a gold film, a functional polypeptide and metal ion chelated magnetic beads; wherein the glass sheet plated with the gold film is fixed on the giant magnetoresistance sensor, one end of a peptide chain of the functional polypeptide is connected with the glass sheet plated with the gold film, and the other end is connected with the metal ion chelated magnetic beads; the giant magnetoresistance biosensor provided by the application can realize monitoring of protease activity, has high sensitivity, strong anti-interference ability, stable performance, and is easy to integrate, so that the giant magnetoresistance biosensor can develop into a portable detection device for large-scale promotion, and has wide application prospects in the fields of diagnosis, treatment and related drug development of major diseases.

The present application relates to lithium battery module operation and maintenance detection technical field, specifically to a kind of lithium battery parallel connection module consistency evaluation method based on magnetic field, comprising the following steps: constructing the consistency evaluation index based on current, index includes module consistency evaluation index and the consistency evaluation index between any two cells in module;Using tunnel magnetoresistance TMR sensor to collect the magnetic field intensity above the tab of parallel connection module;According to Biot-Savart law and the coefficient matrix obtained by calibration, the magnetic field intensity obtained by TMR array sampling is used to inverse each cell current;Using the cell current obtained by inversion, according to the consistency evaluation index, the consistency evaluation of module level and cell level is realized;Beneficial effect is: based on the influence mechanism research of parallel connection module parameter difference on cell branch current distribution, two evaluation indexes according to current measurement value are proposed, to realize the evaluation of module level and cell level, fill the long-standing blank of parallel connection module consistency evaluation index.

A magnetoresistive sensor includes a layer stack containing at least one reference layer having a reference magnetization perpendicular to the plane of the layer stack and at least one free layer having a vortex magnetization. The magnetoresistive sensor furthermore includes at least one soft-magnetic shield arranged adjacent to the layer stack and configured to reduce an influence of an external magnetic field along a shielding axis on the free layer.

The invention discloses a self-driving positioning integrated continuum functional catheter and a pose determination method thereof.The catheter comprises a control unit and at least two functional units, the functional units are coaxially connected in series end to end through a flexible connecting part, and each functional unit comprises a flexible shell, a driving assembly and a sensing assembly; the driving assembly comprises at least three micro motors distributed in the flexible shell in the circumferential direction, output shafts of the micro motors are provided with magnetic elements and wound with traction ropes, and the control unit is electrically connected with all the micro motors and the three-axis magnetoresistive sensor. According to the self-driving and positioning integrated continuum functional catheter and the pose determination method thereof, high integration of driving and positioning is achieved, full-circumferential real-time pose sensing can be completed without external imaging equipment, and the control precision and the intelligent level of an operation catheter are improved.

The invention discloses a magnetic positioning accurate temperature control ablation catheter device for atrial fibrillation radiofrequency ablation, and relates to the technical field of atrial fibrillation radiofrequency ablation. According to the catheter device, the magnetic sensing assembly is arranged, magnetoresistive sensors and a central miniature permanent magnet which are evenly distributed on the circumference are adopted, three-dimensional accurate positioning is achieved in combination with an in-vitro magnetic field, positioning deviation caused by cardiac pulsation is reduced or eliminated, a plurality of miniature thermocouples cover the hemispherical end, and the annular perfusion hole channel, full-dimensional temperature control and uniform cooling are matched; five cavities of the main body section independently avoid winding, a nickel-titanium spring and a double-layer woven wire of the bendable section give consideration to bendability and stability, a core component is made of a biocompatible material, thrombus and allergy risks are reduced, and the device is adaptive to existing equipment and is convenient and durable to operate and control.

The present disclosure concerns a magnetoresistive sensor (MR) element, comprising a reference layer having a reference magnetization; a sense layer having a sense magnetization comprising a vortex configuration stable under the presence of an external magnetic field, the sense magnetization being reversibly movable in a direction out-of-plane relative to the reference magnetization when the external magnetic field varies in a direction out-of-plane; and a tunnel barrier layer between the reference layer and the sense layer. The MR element further comprises a dipolar assisting layer, configured to generate a dipolar stray field oriented substantially out-of-plane, such that the dipolar stray field is added to the out-of-plane external magnetic field, resulting in an effective magnetic field that is larger than and proportional to the external magnetic field. The present disclosure further concerns a magnetic sensor device comprising the MR element.

The invention relates to the technical field of lithium battery module operation and maintenance detection, in particular to a lithium battery parallel module consistency evaluation method based on a magnetic field, comprising the following steps: constructing current-based consistency evaluation indexes including a module consistency evaluation index and a consistency evaluation index between any two cells in a module; collecting the magnetic field intensity above the parallel module tabs by using a tunnel magnetic resistance TMR sensor; according to the Biot-Savart law and the coefficient matrix obtained through calibration, the current of each battery cell is inversed through the magnetic field intensity obtained through TMR array sampling; the cell current obtained through inversion is utilized, and module-level and cell-level consistency evaluation is achieved according to a consistency evaluation index; the method has the beneficial effects that two evaluation indexes according to the current measurement value are provided based on the research on the influence mechanism of the parallel module parameter difference on the current distribution of the battery core branch, so as to realize module level and battery core level evaluation, and fill the blank that there is no evaluation index for the consistency of the parallel module for a long time.

A device including a magnetoresistance sensor for detecting a magnetic field from an ear cavity is disclosed. Methods for detecting a magnetic field from an ear cavity with a magnetoresistance sensor are also disclosed.

The invention relates to the technical field of wireless charging, and relates to a wireless charging mobile power supply and a control method thereof, and the wireless charging mobile power supply comprises a magnetic attraction assembly, a battery module, a switch module, a power supply management module, a wireless charging control module, a wireless charging coil and a tunnel magnetoresistive sensor. The magnetic attraction assembly is arranged on the peripheral side of the wireless charging coil, and a magnetic attraction surface is formed on the magnetic attraction assembly; the input end of the switch module is connected with the voltage output end of the battery module, and the output end is connected with the voltage input end of the wireless charging module; the tunnel magnetoresistive sensor is arranged on the back side of the magnetic suction surface, the magnetic field sensitive direction of the tunnel magnetoresistive sensor is parallel to the magnetic suction surface, and the tunnel magnetoresistive sensor is used for detecting the magnetic field intensity generated by the magnetic suction assembly, outputting a first level signal when the magnetic field intensity is higher than a first preset threshold value and outputting a second level signal when the magnetic field intensity is lower than a second preset threshold value; the power management module is used for controlling the switch module to be turned on or turned off according to the first level signal or the second level signal. According to the method, operation convenience and hardware type selection diversity can be considered, and the method is suitable for special structural design.