Abstract: Disclosed is an eddy current non-destructive inspection device which includes an eddy current probe with a probe conductor resistance dynamically changing due to operation conditions, such as temperature. The device further includes a signal generating circuit generating an inspection frequency signal and a low frequency signal. Sensed inspection frequency signals are processed to produce resulting signals with possible drift. A low frequency processing circuit includes a resistance calculator producing a substantially true value of the dynamic probe resistance, based on which compensation operations are configured to correct the drifted resulting signals and produce corrected resulting signals.

Abstract: According to one embodiment a method of performing a calibration correlation test for a calibration assembly includes sweeping a head module having a magnetic read sensor along a y-axis of the calibration assembly. The calibration assembly has at least one calibration trench having at least one nanoparticle at a known y-axis location in the calibration trench and the magnetic properties are known for the at least one nanoparticle. A read response of the at least one nanoparticles is obtained from the magnetic read sensor and a correlation is determined from the read response. The correlation of the read response is compared to a correlation threshold. The read response correlation is stored in memory in response to determining that the correlation of the read response is greater than the correlation threshold. When the correlation of the read response is not greater than the correlation threshold, a correlation test error is indicated.

Abstract: The present invention relates to resolver calibration for permanent magnet synchronous motor. According to embodiments of the present invention, the high frequency rotating voltage vector is generated and injected into a resolver associated with a permanent magnet synchronous motor (PMSM). Due to the saliency effect, when a reference point is detected in a phase current, the rotor position of the PMSM is known. At this point, by acquiring the resolver position, the resolver offset may be accurately determined for calibration. According to embodiments of the present invention, the resolver offset may be accurately determined and calibrated without increasing device dimension and cost. Respective methods, apparatuses, systems, and computer products are disclosed.

Abstract: One embodiment of the present invention relates to a magnetic field sensor comprising a squat soft-magnetic body disposed on a surface of a substrate comprising a magnetic sensor array having a plurality of spatially diverse magnetic sensor elements disposed in a predetermined configuration. In the presence of an external magnetic field the squat soft-magnetic body becomes magnetized to generate a reactionary magnetic field. The plurality of magnetic sensor elements are respectively configured to measure a magnetic field value of a superposition of the external magnetic field and the reactionary magnetic field along a first axis (e.g., a z-axis), resulting in a plurality of spatially diverse measurements of the magnetic field component along the first axis. The plurality of spatially diverse measurements may be used to compute magnetic field components of the external magnetic field along a plurality of axes (e.g., x-axis, y-axis, and z-axis).

Abstract: In determining an exciter conductor spacing of an exciter conductor of an exciter conductor structure from a sensor element of a calibratable magnetic field sensor, first and second electric currents are impressed into the first and second exciter conductors of the exciter conductor structure to generate first and second magnetic field components in the sensor element of the magnetic field sensor, and a quantity is determined depending on the first and second magnetic field components by means of the sensor element. Further, the exciter conductor spacing of the exciter conductor from the sensor element of the magnetic field sensor is established in dependence on an exciter conductor intermediate spacing between the first exciter conductor and the spaced-apart second exciter conductor and the quantities depending on the first and second magnetic field components.

Abstract: A method for enhancing inspection of components of specific geometry based on Barkhausen noises. The method includes specifying a first calibration curve that is independent of the component geometry, which describes the relationship between surface hardness values and measured Barkhausen noise signals. A first noise signal is determined by the measuring device for a reference component having the specified geometry and a first hardness value. A second noise signal is determined for a second reference component, having the specified geometry and a second hardness value lower than the first. A second calibration curve is determined, in which the first calibration curve is fitted to the first noise signal at the first hardness value and to the second noise signal at the second hardness value, such that using the second calibration curve, the measured noise signal of a component having the specified geometry relates with a surface hardness value.

Abstract: Manufacturing of magnetometer units (20?) employs a test socket (41) having a substantially rigid body (43) with a cavity (42) therein holding an untested unit (20) in a predetermined position (48) proximate electrical connection (50) thereto, wherein one or more magnetic field sources (281, 332, 333, 334, 335, 336) fixed in the body (43) provide known magnetic fields at the position (48) so that the response of each unit (20) is measured and compared to stored expected values. Based thereon, each unit (20) can be calibrated or trimmed by feeding corrective electrical signals back to the unit (20) through the test socket (41) until the actual and expected responses match or the unit (200) is discarded as uncorrectable. In a preferred embodiment, the magnetic field sources (281, 332, 333, 334, 335, 336) are substantially orthogonal coil pairs (332, 333, 334) arranged so that their centerlines (332-1, 333-1, 334-1) coincide at a common point (46) within the predetermined position (48).

Abstract: Provided are a magnetic sensor test apparatus and a magnetic sensor test method. The magnetic sensor test apparatus includes a vertical coil configured to generate a magnetic field and at least one periphery coil. The magnetic sensor test apparatus and method may test a magnetic sensor on a semiconductor wafer.

Abstract: A TMR element and a corrective AMR element are series-connected between a power supply and a ground. The resistance value of the corrective AMR element is set so as to offset an output error in the rotation angle of an external magnetic field, which is included in the resistance value of the TMR element. The resistance value of the corrective AMR element is smaller than that of the TMR element. An increased voltage can be applied from the power supply to the TMR element. It is possible to increase, in the resistance value of the TMR element, the amount of change that depends on the rotation angle of the external magnetic field. This makes it possible to increase, in the output of a magnetic sensor, the amount of change that depends on the rotation angle of the external magnetic field. The sensitivity of the magnetic sensor can be increased.

Abstract: A method and system are provided for calibrating a magnetometer of a mobile device. The method comprises displaying a visual indication of a gestural path on a display of the portable electronic device, monitoring for changes in orientation of the portable electronic device, changing the visual indication in response to the monitored changes in the orientation of the portable electronic device, measuring a magnetic field with the magnetometer, and calibrating the magnetometer in accordance with measurements of the magnetic field acquired at different points along the gestural path.

Abstract: Method and system for measuring the resistance of a resistive structure having at least three nodes. A first calibration signal is determined by measuring a voltage at an output of the resistance structure when no calibration current is injected into a third node between the first and second nodes of the structure. A calibration current is then injected into the third node and a second calibration signal is determined. The absolute value of the difference between the first calibration signal and the second calibration signal is determined, the absolute value being proportional to a product of the resistance of the resistive structure and the calibration current.

Abstract: An apparatus and a method for testing a magnetic field sensor are provided, in which the method includes arranging a coil for generating a magnetic field, applying the magnetic field to the magnetic field sensor using the coil, and detecting the magnetic field applied to the magnetic field sensor.

Abstract: Embodiments related to calibrating a mobile device including a magnetometer during application usage are disclosed. One embodiment provides a method comprising sampling magnetic information received from the magnetometer, and recognizing an initial controller orientation signal derived from a first sample of a plurality of samples of the magnetic information and from directional offset data. The method further comprises calculating updated directional offset data based on the plurality of samples of the magnetic information and on the directional offset data, and deriving a calibrated controller orientation signal from a second sample of the plurality of samples of the magnetic information and the updated directional offset data.

Abstract: According to an embodiment of the invention, an angle detection apparatus detects the angle of a rotation axis of a rotating device to generate a first signal and a second signal perpendicular to the first signal using the angle detection unit. The first AD conversion unit receives the first signal to perform an analog-to-digital conversion of the first signal. The second AD conversion unit receives the second signal to perform an analog-to-digital conversion of the second signal. The first offset correction unit receives a third signal output from the first AD conversion unit to perform an offset correction of the third signal when the third signal is outside a predetermined range. The second offset correction unit receives a fourth signal output from the second AD conversion unit to perform an offset correction of the fourth signal when the fourth signal is outside the predetermined range.

Abstract: A method and system are provided for operating a mobile device having a magnetometer. The method includes obtaining a plurality of error indicators associated with the magnetometer. At least two of the plurality of error indicators have different criteria for error. The method also includes determining an instruction for operating the mobile device using the plurality of error indicators.

Abstract: A method and system are provided for calibrating a magnetometer. The method comprises determining a current quality level associated with magnetometer readings obtained using an active set of calibration parameters; and lowering a quality threshold for a background calibration of the magnetometer when the current quality level exceeds a threshold quality level needed by an application utilizing the magnetometer readings.

Abstract: Implementations are disclosed for validating data retrieved from a calibration database. In some implementations, calibrated magnetometer data for a magnetometer of a mobile device is retrieved from a calibration database and validated by data from another positioning system, such as course or heading data provided by a satellite-based positioning system. In some implementations, one or more context keys are used to retrieve magnetometer calibration data from a calibration database that is valid for a particular context of the mobile device, such as when the mobile device is mounted in a vehicle. In some implementations, currently retrieved calibration data is compared with previously retrieved calibration data to determine if the currently retrieved calibration data is valid.

Abstract: A magnetic field sensing device can include two or more magnetic field sensors configured to detect a magnetic field in a current carrying conductor. The magnetic field sensing device also can include a phase detector electrically coupled to outputs of the two or more magnetic field sensors. The magnetic field sensing device further can include a phase indicator electrically coupled to the phase detector. The phase indictor can include a display that indicates when the two or more magnetic field sensors are in a position in relation to the current carrying conductor. Other embodiments are provided.

Abstract: A magnetic field sensor includes built in self-test circuits that allow a self-test of most of, or all of, the circuitry of the magnetic field sensor, including self-test of a magnetic field sensing element used within the magnetic field sensor, while the magnetic field sensor is functioning in normal operation.

Abstract: The present invention discloses a magnetic field sensing device that utilizes a single coil for calibrating the response of the sensor to compensate for temperature dependent sensitivity drift and also for resetting the magnetic field sensor in order to eliminate hysteresis. The single coil configuration is advantageous since it reduces the size of the sensor chip by decreasing the number of contact pads on the chip and also because it wastes less space, which permits an increase in the density of the magnetoresistive elements on the sensor chip.

Abstract: A self-calibrating magnetic field monitor is disclosed. In one embodiment, a magnetic field sensor repeatedly generates an electronic signal related to the magnetic field. In addition, a calibration module generates a relative baseline signal based on an average value of the electronic signals for a given time period. A comparator compares the electronic signal with the relative baseline signal and generating an output signal if a difference in the comparing is greater than or equal to a threshold.

Abstract: In general, the disclosure is directed to techniques for determining the position of a piston within a linear actuator, such as a hydraulic cylinder, in a more cost effective and less labor-intensive fashion compared to current techniques for determining the position of a piston within a linear actuator. One or more magnets may be operably coupled to the piston, and a linear array of sensors may be disposed along an exterior length of the linear actuator. The sensors may measure the magnetic field generated by the magnet and, based on the measured magnetic field, may determine the location of the piston within the linear actuator.

Abstract: A method for re-calibrating installed downhole sensors used in hydrocarbon wells by the application of a calibration string inserted in the wells and deployed in close proximity to the installed downhole sensor.

Abstract: Systems and methods for using magnetic field readings to refine device location estimates are provided. As an example, a plurality of magnetic field readings can be collected by a device as it travels along a path. A positioning system (e.g., GPS) or other sensors can be used to provide a coarse location for the device at each reading. A contribution to each of the magnetic field readings by the Earth's magnetic field can be removed to obtain a plurality of residual readings and a plurality of regions of interest along the path can be identified based at least in part on the residual readings. The regions of interest can be compared to each other to identify a plurality of correspondences between magnetic field readings or residual readings and the plurality of correspondences can be used to refine the location estimates.

Abstract: A position and orientation system and method is provided. A magnetoresistance sensor is provided having a sensor array configured to measure magnetic fields and a metallic coil positioned within the magnetoresistance sensor. In certain embodiments, the magnetic coil may be used to generate a known magnetic field that, when measured by the sensor array, may be used to determine or update a calibration constant for the system.

Abstract: Methods and apparatus for an integrated circuit having a magnetic sensing element, a fault detection module including circuitry to detect a fault condition and to self-test operation of the circuitry to detect the fault. The integrated circuit includes a fault pin to indicate the fault condition.

Abstract: A magnetic-field sensor and a method of calibrating a magnetic-field sensor are disclosed. In one embodiment the method includes supplying the measurement arrangements with an excitation signal to generate a tappable measuring signal at each measurement tap of the measurement arrangements, detecting the measuring signals, evaluating the detected measuring signals by comparing the detected measuring signals with a comparison value, determining the measurement arrangement with a smallest difference, in terms of magnitude, between the detected measuring signals and the comparison value, and choosing the measurement arrangement with the smallest difference for a measurement operation of the magnetic-field sensor. The magnetic-field sensor includes a plurality of magnetoresistive sensor elements connected to form measurement arrangements each measurement arrangement including a measurement tap, wherein the magnetoresistive sensor elements are laterally distributed on a chip of the magnetic field sensor.

Abstract: In an embodiment, a circuit is configured to produce a magnetic field signal having a frequency spectrum. The circuit may also produce a temperature signal. A modulation circuit may modulate the temperature signal with a frequency outside the frequency spectrum of the magnetic field signal. The modulated signal and the magnetic field signal may be combined to produce a combined signal. A separation circuit may be configured to separate component signals from the combined signal. The separation circuit may include a first filter, which, when applied to the combined signal, produces a filtered signal; a modulation circuit configured to shift the data representing the temperature signal to a baseband frequency; and a second filter configured to separate the data representing the temperature signal from the combined signal.

Abstract: A magnetic field sensor can provide an output signal indicative of a passing condition or a failing condition of the magnetic field sensor. The output signal has one of a variety of output signal formats.

Abstract: The invention relates to a system for calibrating and measuring the magnetizability of at least a part of a rail, for instance a rail for guiding means of transport. The system includes a magnetic field generator for generating a changing magnetic field transverse to a longitudinal direction of the rail. The magnetic field generator comprises a substantially saddle-shaped transmitter coil arranged to be placed partly around the rail. The system further includes an induction detector for measuring a transverse induction. The system may further include a magnetic field generator for generating a changing magnetic field in the longitudinal direction, an induction detector arranged for measuring a longitudinal induction, and a processing unit arranged for determining a reference induction, on the basis of the transverse induction, and determining a longitudinal mechanical stress in rail on the basis of the longitudinal induction and the reference induction.

Abstract: A variable geometry turbine of the kind used in a turbocharger has a variable geometry element such as a nozzle ring or an annular array of swing vanes that is operated by an actuator. The actuator has an output shaft coupled to a transmission mechanism for moving the variable geometry element. A rotary sensor device coupled to the output shaft of the actuator has a sensor wheel with a stop, slip clutch mechanism and a rotary position sensor. The device converts movement of the actuator output shaft into rotation of the wheel and the sensor generates an output signal representative of the rotary position of the wheel to provide a value indicative of the position of the variable geometry element.

Abstract: An integrated magnetoresistive sensing device includes a substrate, a magnetoresistive sensing element and a built-in self test (BIST) unit. The substrate comprises a first surface and a second surface opposite to the first surface. The magnetoresistive sensing element is disposed above the first surface and comprises at least a magnetoresistive layer not parallel to the first surface. The BIST unit is disposed above the first surface and comprises at least a conductive part corresponding to the magnetoresistive layer. The conductive part is configured to generate a magnetic field along a direction perpendicular to the first surface. A projection of the conductive part on the first surface does not overlap with a projection of the magnetoresistive layer on the first surface.

Abstract: An illustrative packaged magnetic field sensor includes a power input terminal and a sensor output terminal, both accessible from outside of the package housing. A sensing block is situated in the package housing and electrically coupled to the magnetic field sensing device and the sensor output terminal. An adjustment block is situated in the package housing and coupled to the power input terminal and the sensing block. In some cases, the adjustment block may receive one or more messages that include sensor adjustment information. The one or more messages may be modulated onto the power input signal. The adjustment block may decode the received sensor adjustment information from the messages, and store the decoded adjustment information into a memory. The adjustment block may then adjust the output signal of the sensing block based on the decoded adjustment information.

Abstract: A circuit to detect a movement of an object includes a magnetic field sensing element for generating a magnetic field signal proportional to a magnetic field associated with the object and a motion detector to generate a motion signal indicative of the movement of the object. The motion detector includes a peak identifying circuit to provide a peak signal and a peak sample selection module that selects a sample associated with one or more prior cycles of a magnetic field signal to generate a selected peak signal. The motion detector further includes a threshold generator to generate a threshold signal as a function of the selected peak signal and a comparator to compare the threshold signal with the magnetic field signal to generate the motion signal. Peak samples from prior magnetic field signal cycles may be averaged for use to establish the threshold signal. A method associated with the circuit is also described.

Abstract: Magnetic tracking systems and methods for determining the position and orientation of a remote object. A magnetic tracking system includes a stationary transmitter for establishing a reference coordinate system, and at least one receiver. The remote object is attached to, mounted on, or otherwise coupled to the receiver. The transmitter can include a set of three mutually perpendicular coils having a common center point, or a set of three coplanar coils with separate centers. The receiver can include a set of three orthogonal coils. The position and orientation of the receiver and the remote object coupled thereto is determined by measuring the nine mutual inductances between the three transmitter coils and the three receiver coils. The magnetic tracking system provides reduced power consumption, increased efficiency, digital compensation for component variation, automatic self-calibration, automatic synchronization with no connections between transmitter and receiver, and rapid low-cost implementation.

Abstract: A real-time calibration system and method for a mobile device having an onboard magnetometer uses an estimator to estimate magnetometer calibration parameters and a magnetic field external to the mobile device (e.g., the earth magnetic field). The calibration parameters can be used to calibrate uncalibrated magnetometer readings output from the onboard magnetometer. The external magnetic field can be modeled as a weighted combination of a past estimate of the external magnetic field and the asymptotic mean of that magnetic field, perturbed by a random noise (e.g., Gaussian random noise). The weight can be adjusted based on a measure of the statistical uncertainty of the estimated calibration parameters and the estimated external magnetic field. The asymptotic mean of the external magnetic field can be modeled as a time average of the estimated external magnetic field. are within the scope of the following claims.

Abstract: Embodiments of the invention described herein provide a magnetic sensor interface capable of adjusting signal conditioning dynamically such that the true positive and negative peaks of the input signal are maintained for a given target across its entire speed range (0-Max rpm), therefore increasing the signal to noise ratio at low speeds and avoiding clipping or distortion at high speeds. In one aspect, a method comprises receiving an alternating differential voltage signal from a sensor. The alternating differential voltage signal has an amplitude that changes over time. The alternating differential voltage signal is converted to an attenuated single-ended voltage signal that can be dynamically scaled. The attenuated single-ended voltage signal can be scaled by multiplying the attenuated single-ended voltage signal by a scaling factor. The scaling factor is selected relative to a signal-to-noise ratio of the scaled attenuated single-ended voltage signal.

Abstract: A magnetic field sensor includes a diagnostic circuit that allows a self-test of most of, or all of, the circuitry of the magnetic field sensor, including a self-test of a magnetic field sensing element used within the magnetic field sensor. The magnetic field sensor can generate a diagnostic magnetic field to which the magnetic field sensor is responsive.

Abstract: A flex circuit for creating artificial defects uses a thin conductive layer with rectangular slots therein representing defects. A thin insulating over-layer is used to protect the conductive layer as well as an eddy current probe. The flexible circuit is then temporarily attached to the surface of the part or material to be inspected. A feature of the described system is that it is directly scalable to an electric discharge machined (EDM) notch. In an embodiment, a thin conductive layer is used which is scalable to a thicker lower conductive layer like a conventional EDM notch. In this way, a thin conductive artificial defect can electromagnetically represent a thicker albeit less conductive EDM notch. The flexible circuit makes it easier to place multiple notches in complex part geometries, and allows for more accurate relative positioning between slots, e.g., for array and wide coverage probes.

Abstract: The invention is a method, described with the appropriate auxiliary electronic circuitry, for compensating the effect of the earth's magnetic field on Giant Magneto-Impedance magnetic sensors. The method as taught is an alternate way of cancelling out the effect of the very large residual earth's magnetic field using an impedance-tuning circuit (i.e. electrical compensation) rather than the usual magnetic type of compensation.

Abstract: A magnetic field sensor includes a reference-field-sensing circuit channel that allows a calibration or a self-test of the circuitry of the magnetic field sensor. The magnetic field sensor can generate a reference magnetic field to which the magnetic field sensor is responsive.

Abstract: A hall effect device includes an active Hall region in a semiconductor substrate, and at least four terminal structures, each terminal structure including a switchable supply contact element and a sense contact element, wherein each supply contact element includes a transistor element with a first transistor terminal, a second transistor terminal, and a control terminal, wherein the second transistor terminal contacts the active Hall region or extends in the active Hall region; and wherein the sense contact elements are arranged in the active Hall region and neighboring to the switchable supply contact elements.

Abstract: Embodiments of the present invention provide an electromagnetic sensor (400) for detecting a microstructure of a metal target, comprising: a magnetic device (410, 420) for providing an excitation magnetic field; a magnetometer (430) for detecting a resultant magnetic field induced in a metal target; and a calibration circuit (450, 551, 552, 553, 554) for generating a calibration magnetic field for calibrating the electromagnetic sensor, wherein the calibration reference magnetic field is generated by an electrical current induced in the calibration circuit by the excitation magnetic field.

Abstract: A method for quasi-static testing a magnetic recording head read sensor is described. The method includes applying a first voltage to a heater in the magnetic recording head and measuring an output of the magnetic recording head read sensor while applying the first voltage to the heater and recording the measured output as a first set of measurements. The method further includes applying a second voltage to the heater in the magnetic recording head and measuring the output of the magnetic recording head read sensor while applying the second voltage to the heater and recording the measured output as a second set of measurements. The first and second sets of measurements are then compared.

Abstract: Magnetic tracking systems and methods for determining the position and orientation of a remote object. A magnetic tracking system includes a stationary transmitter for establishing a reference coordinate system, and at least one receiver. The remote object is attached to, mounted on, or otherwise coupled to the receiver. The transmitter can include a set of three mutually perpendicular coils having a common center point, or a set of three coplanar coils with separate centers. The receiver can include a set of three orthogonal coils. The position and orientation of the receiver and the remote object coupled thereto is determined by measuring the nine mutual inductances between the three transmitter coils and the three receiver coils. The magnetic tracking system provides reduced power consumption, increased efficiency, digital compensation for component variation, automatic self-calibration, automatic synchronization with no connections between transmitter and receiver, and rapid low-cost implementation.

Abstract: The invention concerns a system for measuring the alignment error of two axles provided with a first and a second coupling part by means of a biaxial orthogonal magnetic sensor system comprising a sensor and a magnet, wherein said sensor is designed to be placed on the first coupling part with its one direction of sensing oriented in one direction of magnetization of said magnet, which magnet is designed to be placed on the other coupling part and means for reading off an angle error and offset error independently of each other during the rotation of the axles on-line. The system moreover includes a reference sensor for determining said angle error and offset error orientation relative to a known direction.

Abstract: An inductive sensor including a casing in which are positioned: a ferromagnetic core having a U shape, which core includes two external branches and a transverse branch linking the two branches; two detection coils disposed respectively on the external branches of the core; a calibration mechanism positioned between the two external branches of the magnetic core, a longitudinal positioning of the calibration mechanism with respect to an end of the external branches being adjustable; an intermediate fixing piece for fastening the calibration mechanism onto the ferromagnetic core, the intermediate fixing piece being placed forcibly in an opening made in the transverse branch, the calibration mechanism including a threaded zone configured to be screwed into a smooth hole made in the intermediate fixing piece.

Abstract: An integrated magnetic field generation and detection platform is described that is capable of manipulating and detecting individual magnetic particles, such as spherical super-paramagnetic beads, and providing biosensing functionality. The platform is implemented in an integrated circuit, a portion of the surface of which is functionalized with one or more biochemical agents that binds tightly (i.e., specifically) with a target analyte. The magnetic beads are similarly functionalized with one or more biochemical agents that that bind specifically with the target analyte. When a sample is introduced, magnetic beads that specifically bind to the integrated circuit can be separated from non-specifically bound beads and detected.

Abstract: A magnetic field sensor includes a diagnostic circuit that allows a self-test of most of, or all of, the circuitry of the magnetic field sensor, including a self-test of a magnetic field sensing element used within the magnetic field sensor. The magnetic field sensor can generate a diagnostic magnetic field to which the magnetic field sensor is responsive.

Abstract: Apparatus, systems, and methods are provided for sensing devices. An exemplary sensing device includes a sensing arrangement on a substrate to sense a first property, a heating arrangement, and a control system coupled to the first sensing arrangement and the heating arrangement to activate the heating arrangement to heat the first sensing arrangement and deactivate the heating arrangement while obtaining one or more measurement values for the first property from the first sensing arrangement.