Abstract: A measurement system includes a rotating member configured to transfer mechanical energy to a point of use. The member has at a surface thereof one or more circumferentially oriented bands of magnetizable material. Each band has a magnetic pattern comprised of a plurality of transitions magnetically recorded in the magnetizable material of that band. A magnetic-field sensor is disposed sufficiently near each band of magnetizable material to sense a magnetic pattern recorded in that band as the member rotates. Each magnetic-field sensor generates signals in response to the magnetic pattern sensed by that magnetic-field sensor. Processing electronics is in communication with each magnetic-field sensor to receive the signals generated by that magnetic-field sensor while the member rotates and to dynamically compute from the signals a measurement associated with a performance of the rotating member.

Abstract: A measurement system includes a rotating member configured to transfer mechanical energy to a point of use. The member has at a surface thereof one or more circumferentially oriented bands of magnetizable material. Each band has a magnetic pattern comprised of a plurality of transitions magnetically recorded in the magnetizable material of that band. A magnetic-field sensor is disposed sufficiently near each band of magnetizable material to sense a magnetic pattern recorded in that band as the member rotates. Each magnetic-field sensor generates signals in response to the magnetic pattern sensed by that magnetic-field sensor. Processing electronics is in communication with each magnetic-field sensor to receive the signals generated by that magnetic-field sensor while the member rotates and to dynamically compute from the signals a measurement associated with a performance of the rotating member.

Abstract: A position-sensing system includes a first component (e.g., a cylinder) and a second component (e.g., a piston rod) movably coupled to the first component for movement with respect thereto. A magnetically hard layer on the second component provides a recording medium. Regions of the magnetically hard layer are magnetized as magnetized rings around the second component. Magnetic-field sensors are coupled to the first component in proximity of the magnetically hard layer on the second component to sense the rings of magnetized regions. Each of the magnetic field sensors senses flux from each of the rings of magnetized regions as the second component is moving with respect to the first component and, in response to sensing the rings of magnetized regions, generates signals used to determine position of the second component.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. A track comprised of a plurality of magnetized regions is magnetized in the magnetically hard layer. A plurality of magnetic-field sensors is coupled to the cylinder in proximity of the magnetically hard layer to sense the magnetized track while the piston rod is moving with respect to the cylinder. A first one of the magnetic field sensors is positioned over the track to sense the magnetized regions of the track serially and a second one of the magnetic field sensors is positioned radially to one side of the track. The magnetic field sensors generate signals, in response to sensing the magnetized regions, for use in measuring rotational movement of the piston rod.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. Information is perpendicularly magnetized in regions of the magnetically hard layer. These regions provide an encoding scheme for determining the position of the piston rod. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the piston rod when the machinery is off.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. Information is perpendicularly magnetized in regions of the magnetically hard layer. These regions provide an encoding scheme for determining the position of the piston rod. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the piston rod when the machinery is off.

Abstract: A position-sensing system magnetically senses the position of a first component moving with respect to a second component. A magnetically hard layer on the first component provides a recording medium. Information is magnetically recorded in regions of the magnetically hard layer. These regions provide a relative encoding scheme for determining the position of the first component. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the first component moves with respect to the second component. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the first component when the machinery is off.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. Information is magnetically recorded in regions of the magnetically hard layer. These regions provide a relative encoding scheme for determining the position of the piston rod. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the piston rod when the machinery is off.