Abstract: A method of tracking translation and rotation of one or more objects within a region of interest. The method includes providing a passive transponder in the region of interest, the transponder having a position and an orientation, generating an electromagnetic field in the region of interest, causing the transponder to generate electromagnetic signal, mapping the electromagnetic field and the signal as functions of the position and the orientation of the transponder, fixing the transponder to the object being tracked, receiving the signals generated by the transponder while the transponder is fixed to the object being tracked, and processing the signal, with reference to the functions, to compute the three-dimensional translational position and three-axis rotational orientation of the object.

Abstract: This invention pertains to a method and apparatus for determining the thickness of a ferromagnetic or paramagnetic material when only one side of the material is accessible. In one embodiment, the invention provides a method for engaging a constant signal with the ferromagnetic material for inducing a changed signal, generating a stepped saturation signal over a range of currents for engagement with the ferromagnetic material, detecting the changed signal as the saturation signal is varied over the range of currents, determining the relationship between the changed signal and the stepped saturation signal, and evaluating the thickness of the material based upon the relationship between the changed signal and the stepped saturation signal.

Abstract: A current sensor assembly includes a sensor coil, an electrostatic shield coil, a core, a housing, and a magnetic shield. The sensing coil, electrostatic shield coil, core, housing, and magnetic shield can be of toroidal symmetry and arranged coaxially about a pair of primary current conductors. The conductors can be either asymmetric or symmetric with respect to the geometric center of the remaining sensor assembly. The core and a secondary winding make up a current sensor. The core is cylindrically shaped and fabricated of non-magnetic material. The secondary winding is wound over the cylindrical core to form a toroidally shaped winding. When assembled into the current sensor assembly, the core and windings are disposed around two single turn primary windings through which AC currents to be measured flow. Alternatively, the conductor can be flat and the sensor can be a solid state sensor that includes an electrostatic shield.

Abstract: A rotation detecting apparatus including a drive gear rotatably supported by a case having a cover and capable of rotating cooperatively with an object to be detected, driven gears and brought in mesh with the drive gear and capable of rotating cooperatively therewith, magnets and provided at rotational center portions of the driven gears and having plane portions formed with N poles and S poles, a circuit board arranged at the case and capable of connecting to outside, magnetic reluctance elements attached to the circuit board and being opposed to the plane portions of the magnets and an electronic circuit part for converting an output signal of the magnetic reluctance element into a rotational angle signal, wherein the driven gears and are interposed by the case and the cover and a constant distance is maintained between the plane portion and the magnetic reluctance element.

Abstract: A sensor for measuring a magnetic field includes a substrate, four magnetic elements arranged in a bridge configuration on the substrate, a first bridge portion. A first element and a second element are connected in series, a second bridge portion, and a third element and a fourth element are connected in series, being situated between a first contact and a second contact. The first bridge portion includes an electrical shunt resistor, which is arranged parallel to the first magnetic element of the bridge. In order to compensate for offset voltage and offset voltage drift in the output voltage of the bridge configuration, the temperature coefficient of the shunt resistor compensates for the variation of the temperature coefficients of the magnetic elements in the bridge.

Abstract: A contactless latch engagement detector for a mechanical fastening system operating on the principle of magnetosensitivity. A magnetosensitive switch composed of a magnetosensitive device and at least one biasing magnet adjacent the magnetosensitive device are located in a buckle. Within or external to the buckle is an electronic circuit for driving the magnetosensitive device, and a flux bar composed of a ferromagnetic material having a high magnetic permeability is associated with a movable component of the system. In operation, the electronic circuit drives the magnetosensitive device, wherein its output is responsive to position of the flux bar relative to the magnetosensitive device. The flux bar moves responsive to position of a tongue within the buckle, whereby the fastened state of the mechanical (ie., seat belt) fastening system is detected when a predetermined output occurs.

Abstract: The magnetic powder for validity determining ink is composed of magnetic oxide powder having a Curie temperature between −50° C. and 150° C. and a mean powder particle diameter of 10 &mgr;m or less.

Abstract: A method for determining a “safe-operation” point for a metal structural element subjected to repeated loading, the same or different, generating variable levels of strain and residual stress in the worked element; and, predicting the imminent failure of the structural element. The surface of the metal element is worked to provide a residual strain, for example, by shot-peening. Measurements of electrical conductivity are compared at various chosen frequencies corresponding to different depths in the “near-surface” of the element. Similar measurements are made in the near-surface of a “standard” and a first difference is computed between the conductivity of the shot-peened surface and the “standard” surface. This first difference provides a basis for comparison of the effects of residual stress after successive loadings of the shot-peened metal element.

Abstract: Tracking a boring tool is performed within an underground region using a locating signal. The boring tool is moved through the ground during a series of distance movements such that potential movement of the boring tool during any one of the distance movements is less than a maximum movement value. A current positional relationship is determined for a current one of the distance movements based on: a last-determined positional relationship established for an immediately preceding one of the distance movements, certain orientation parameters, the maximum movement value and the determined signal strength of the locating signal in the current positional relationship. Target coordinates are accepted and a target position, based on the target coordinates, is included as part of the current positional relationship. The position of the target is unconstrained with respect to system geometry. Steering command features are provided along with steering warnings.

Abstract: An apparatus and method for the repeatable detection and recording of low-threshold molecular electromagnetic signals. The sample material and detection apparatus are contained with a magnetically shielded faraday cage to shield them from extraneous electromagnetic signals. The detection apparatus includes a detection coil and Super Conducting Quantum Interference Device (“SQUID”). White noise is injected external to the SQUID and the signals emitted by the sample material enhanced by stochastic resonance.

Abstract: A pulse signal generator comprises a magnetic element (1) capable of producing large Barkhausen jumps; a generating unit for generating a magnetic field, which is changed by the object to be detected (5) to cause the magnetic element to produce the large Barkhausen jumps; the generating unit consists of a pair of elongated magnet/yoke combinations (3,6 and 4,7) provided on opposite sides of the magnetic element (1) such that their poles are oriented in opposite directions, forming a detecting area at an end thereof (3A, 4A); a detecting unit (2) for detecting the large Barkhausen jumps to produce a corresponding pulse signal; the magnetic element (1) having a first length between a second length of the magnet/yoke combinations and a half of the second length and provided toward the detecting area; and an adjusting yoke (8) movable along one of the elongated magnet/yoke combinations (3, 6).

Abstract: A method for investigating subterranean strata. An electromagnetic field is applied using a dipole antenna transmitter and this is detected using a dipole antenna receiver. Phase information is extracted from a refracted wave response and used to identify the presence and/or nature of a subterranean reservoir.

Abstract: A displacement detector has a contact sensor incorporating a differential transformer and a circuit for adjusting the amplitude of the driving signal for driving a differential transformer of the sensor by feeding back as a standard signal the driving signal through an amplifier and an AC-DC converter as a standard signal. The sensor has a housing containing a mobile member. The mobile member has a shaft with a hole. An outer tubular body of a linear bush and a ball guide each have a hole, and a pin is inserted through these holes movably in the direction of movement of the mobile member such that the rotation of the mobile member is prevented.

Abstract: Single coil to be excited by a predetermined A.C. signal is provided, with no secondary coil being provided. Magnetism-responsive member is movable relative to the coil so that a self-inductance of the coil progressively increases or decreases in response to displacement of an object to be detected within a predetermined range and a voltage of the coil corresponding to the self-inductance is produced. Predetermined reference voltage is generated and subjected to analog operations with the coil output voltage, to thereby generate first and second A.C. outputs having, as amplitude coefficients, first and second cyclic amplitude functions correlated to the position to be detected. The position is detected on the basis of the phase component of the amplitude coefficient functions. Combination of two coils and one reference voltage may be employed.

Abstract: A magnetic sensor comprises a thin-film-like magnetic tunnel effect element (magnetoresistive effect element) 11. A coil 21 is disposed in a plane under the magnetic tunnel effect element 11 and parallel to a thin-planar film surface of the element. The coil 21 is a double spiral type coil which includes a first spiral conductor portion 21-1 and a second spiral conductor portion 21-2. The magnetic tunnel effect element 11 is disposed between a spiral center P1 of the first conductor portion 21-1 and a spiral center P2 of the second conductor portion 21-2 in a plan view. The first and second conductor portions 21-1 and 21-2 are connected such that electric currents in the same direction pass through a part of the first conductor portion 21-1 that overlaps the magnetic tunnel effect element 11 in a plan view and through a part of the second conductor portion 21-2 that overlaps the magnetic tunnel effect element 11 in a plan view.

Abstract: Even when a cheap magnetic responsive element is used for a magnetic detecting portion, a rotation detector excellent in vibration resistance is provided, a housing 1 being provided with a tubular insertion portion 1a through which an axle 13 is inserted. A rotor 5 is provided with a cylindrical portion 5a through which the insertion portion 1a is inserted and that has a plurality of magnetic poles and rotates synchronously with a front wheel (wheel) 11 fitted to the axle 13. The magnetic detecting portion (rotation detecting portion) 3 detects a change of magnetic poles accompanying the rotation of the cylindrical portion 5a. A spacer (magnetic member) 4 is disposed in the surroundings of the insertion portion 1a of a bottom portion 1g of the housing 1, and holds the rotor 5 at the bottom portion 1g when the cylindrical portion 5a is fitted into the insertion portion 1a.

Abstract: An apparatus and method for inspecting contours formed along a predetermined region of a surface on a workpiece formed of an electrically conductive material using eddy current. A probe includes a longitudinal axis and is moveable along a path of travel with respect to the predetermined region to be inspected on a workpiece. At least two coils are spaced longitudinally from one another and supported by the probe to be electrically excited with a predetermined frequency and amplitude during movement of the probe along the path. Sensors are provided for measuring the excitation voltage of each coil as eddy currents are induced in the electrically conductive material of the workpiece by the coils supported on the probe moving along the path of travel with respect to the workpiece.

Abstract: A system for investigating subterranean strata. An electromagnetic field is applied using a fixed dipole antenna transmitter and this is detected using a dipole antenna receiver. The receiver is moved from one location to another in dependence upon the strength of the detected signal.

Abstract: A position sensor includes a shaft to be detected, a first magnet being fixed to the shaft and having a first polarity vector parallel to an axis of the shaft, a second magnet being disposed opposite to the first magnet and having a second polarity vector crossing the first polarity vector substantially orthogonally three-dimensionally, and first and second semiconductor magnetoresistive elements being disposed over the second magnet and functioning as a magnetoelectric transducer having a magnetosensitive axis substantially orthogonal to the first and second polarity vectors. The first and second elements generate an output responsive to an axial movement of the shaft.

Abstract: An electronic sensor assembly that can be used in speed-sensing applications such as anti-lock brake systems. The sensor assembly includes a sensor element, a housing surrounding the sensor element, a sensor terminal connected to the sensor element and extending outside of the housing for electrically coupling the sensor element to a conductor, a connector terminal for mechanically and electrically coupling the sensor terminal to the conductor, and a splice band mechanically and electrically coupling the sensor terminal to the connector terminal without welding, soldering, or using a crimp bucket. In one aspect of the invention, the sensor assembly further includes a capacitor electrically and mechanically coupled to the sensor terminal and the connector terminal via the splice band. The sensor element is preferably an active sensor such as a magneto-resistive sensor or a Hall-Effect sensor.