Gm Global Technolgoy Operations, Inc.

Hughes Aircraft Company

Delco Electronics Corporation

Bruno P Lequesne

Thaddeus Schroeder

Thomas Arthur Perry

Rassem Ragheb Henry

John Robert Bradley

Robert W Ward

Chi Hung Leung

Raymond O Butler, Jr

Balarama Vempaty Murty

Anthony L Marks

Dale Lee Partin

Frederick E Pinkerton

Martin Stephen Meyer

Brian K Fuller

Donald E Lake

Hiro Yamasaki

Jackson G Gay

George A Shinkle

Daniel I Feaster

John S Zgunda

Robert A Frosch

A method is disclosed for equalizing the electrical resistance of two or more magnetoresistor sensor elements positioned on a permanent magnet in a sensor assembly. The method may utilize a laser to reduce the magnetic field of the portion of the permanent magnet underlying the sensor with the higher electrical resistance.

Method of matching magnetoresistors in a sensor assembly

An apparatus for detecting precise angular positions of a rotating object. Two magnetoresistors (MRs) are positioned adjacent a target wheel attached to the rotating object, the target wheel having at least one element of finite length. Each MR is responsive to the passage of at least one of the elements as the target wheel is rotated, generating an analog signal with signal transitions between two voltage levels at the passage of the element's leading and trailing edges. The MRs are positioned relative to the elements such that their signals are phase shifted with respect to one another, resulting in time overlapping signals which intersect at a precise angular positions of the target wheel.

Magnetoresistive encoder for tracking the angular position of a rotating

A rotation sensor includes a binary encoded target wheel and a pair of sensors disposed about the target wheel periphery. One of the sensors provides a signal indicative of the passage of regular angular intervals of the target wheel and the other of the sensors provides binary states corresponding to the regular angular intervals.

High accuracy angle based rotation sensor with time based back up

A rotation sensor has a target wheel including first and second tracks and a dual-element magnetoresistive sensor. Each individual magnetoresistive element is aligned with a respective track of the target wheel to provide substantially inverse resistive changes with the passage of the wheel. One of the tracks is characterized by alternating high and low permeability, such as by a toothed section, and the other of the tracks is characterized by invariant permeability.

Rotational sensor including axially adjacent targets one of which having

A rotation sensor for high accuracy angle applications such as internal combustion engine crankshaft position sensing includes a pair of complementary target wheels and a dual-element magnetoresistive sensor. The target wheels are spaced from one another along the rotational axis by a predetermined distance. The individual magnetoresistive elements are similarly spaced one from the other and are influence by the ferrite effects of the target wheels. The spacing of the target wheels and magnetoresistive elements are selected in relation to one another and in relation to the mount of axial play in the crankshaft such that changes in ferrite effects of the target wheels upon the elements due to axial displacements of the crankshaft have minimal effect on the accuracy of the sensing apparatus.

Rotational sensor with robust axial alignment tolerance

A motor control includes position transducers for generating crankshaft position and motor position pulse trains. The pulse trains are compared to detect any phase difference between engine and motor. Tables are generated to define the desired phase difference needed for particular valve characteristics. The phase difference represents the instantaneous deviation from the basic profile. One of the tables is selected according to the engine conditions and the motor is driven to achieve the desired phase differences.

Method and apparatus for electrically driving engine valves

A method and apparatus for detecting an engine crankshaft angular position which provides for fast starting of the engine. A target wheel and sensor combination generate an analog signal which is convened into a 24 bit digital output which repeats every 360.degree. rotation of the crankshaft. Each bit represents a particular angular position of the crankshaft. Any 6 sequential bits in the repeating 24 bit digital output sequence form a unique pattern. By monitoring the first six bits generated (90.degree. of crankshaft rotation) during startup, a crankshaft angular position can be determined, thereby enabling fast starting of the engine.

Method and apparatus for detecting crankshaft angular position

A magnetic field sensor assembly comprising a flexible circuit board having a major surface with a predetermined area for receiving at least one semiconductor magnetic field sensor chip, the chip is affixed to the predetermined area of the flexible circuit board in relationship to a predetermined reference location, which reference location can be used in encapsulation and/or use of the magnetic field sensor chip. Several magnetic field sensor chips can be readily, closely disposed on the flexible circuit board in predetermined known locations. The circuit board can conform to any desired predetermined shape. The shape can be determined by a circuit's conformation on a supporting magnet body.

Ultrathin magnetoresistive sensor package

A cam mechanism is employed to convert motor rotation to reciprocating valve motion. Motor speed is reduced at the valve opening and closing times to reduce stress on the cam mechanism.

A magnetized or unmagnetized body of a permanent magnet material is heated in a pattern by a laser beam to a temperature sufficient to lower the coercivity of selected heated regions of the pattern and exposed to a magnetic field to magnetize or to remagnetize the selected heated regions. A pattern guide is used in the process to densify the pattern. In the process, energy is directed through the pattern guide and onto the selected regions, while the pattern guide prevents or minimizes heating of unselected portions of the body. Magnets so produced can have very high pole density, digital encoding and analog patterns having gradually varying local field strength.

Method for thermomagnetic encoding of permanent magnet materials

An article comprising first and second bodies of permanent magnet material, each of said first and second bodies consisting substantially of a substrate of permanent magnet material being magnetized substantially uniformly to a predetermined flux density in a range from zero flux to 100% flux saturation of the permanent magnet material; each of the first and second bodies also comprising a pattern of at least one affected volume in a surface of the body, wherein each affected volume has a magnetic flux density that varies from the substantially uniform predetermined flux density and wherein the first and second bodies are stacked and fixedly attached so that the pattern on each body aligns with the pattern on the other body, wherein at least one affected volume on the first body is aligned with at least one affected volume on the second body and wherein the aligned affected volumes comprise a pole detectable by a magnetic sensor.

Thermomagnetic encoding method and articles

An apparatus comprising a rotating element, a rotary to linear converter, a linearly moving element that linearly extends and retracts when the rotating element rotates in first and second directions, a rotary sensor assembly, integrally constructed with the rotating element, for determining relative movement of the rotating element and for thereby determining relative movement of the linearly moving element, a linear sensor assembly, integrally constructed with the linearly moving element, for providing an absolute position signal each time that the linearly moving element extends or retracts to a predetermined position.

Position sensor for electromechanical suspension

Each valve of an internal combustion engine is driven by a separate rotary electric motor. A cam mechanism for the valves comprises a cylindrical cam in line with the motor axis and the valve stem, the mechanism having inner and outer cylinders, one cylinder rotating with the motor and carrying a cam and the other containing a cam follower and reciprocating with the valve.

A semiconductor magnetoresistive sensor and a method for its assembly is specifically provided. The preferred assembly method of this invention is compatible with automated semiconductor chip placement and packaging technology, so as to alleviate the previous requirement that the semiconductor sensing element be separately packaged. The sensor leads are substantially embedded within a powdered metal permanent magnet body. An exposed terminal end of each lead is available for electrical and adhesive contact to a subsequently attached magnetoresistive semiconductor sensing element, using conventional semiconductor placement and packaging techniques. The powdered metal magnetic body is preferably formed by utilizing powder metal compaction techniques, wherein the powder metal is compacted around the interior electrical leads. The teachings of this invention may also be employed to form a variety of electrical sensors and devices, wherein the leads are substantially embedded within a metal core so as to produce a solid assembly. The embedded leads may have a variety of shapes, such as straight or coiled, may range in number from one to a plurality, and may have a variety of physical properties, such as magnetic or non-magnetic, depending on the desired application.

Sensor assembly having embedded wires within a powder metal core and a

A package for a magnetic field sensitive element, such as a magnetoresistor, includes at least two planar layers of a relatively stiff ferromagnetic material which is also electrically conductive. The layers have opposed edges which are in closely spaced relation to form a narrow gap therebetween. A terminal tab is integral with and extends from each layer. A magnetic field sensitive element is on a surface of at least one of the layers and preferably extends across the gap to be on both layers. The magnetic field sensitive element has a pair of contacts each of which is electrically connected to a separate one of the layers. A permanent magnet is mounted on and insulated from the surface of the layers opposite the magnetic field sensitive element. A protective layer of an insulating material may cover the magnetic field sensitive element and the layers with the terminal tabs extending therefrom.

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Troy, MI, United States of America

Bruno P Lequesne