System and method of magnetically sensing position of a moving component

A method for sensing a position of a first component moving relative to a second component, the method comprising:

• forming a magnetically hard layer on the first component to provide a recording medium for storing information;
• magnetically recording information at a plurality of regions of the magnetically hard layer along a direction of motion of the first component;
• reading, by a plurality of magnetic field sensors, the same magnetically recorded regions of the magnetically hard layer while the first component is moving relative to the second component;
• generating output signals by the plurality of magnetic field sensors from which a position of the first component with respect to the second component can be determined;
• and
• supplying electrical power to the plurality of magnetic field sensors and associated read-head electronics when a machine integrated with the components is off so that the magnetic field sensors can detect movement of the first component with respect to the second component while the machine is off.

An apparatus, comprising:

• a first component;
• a second component movably coupled to the first component for movement with respect thereto;
• a magnetically hard layer formed on the second component to provide a recording medium, a plurality of regions of the magnetically hard layer being magnetized to provide an encoding scheme for determining a position of the second component relative to the first component;
• a plurality of magnetic-field sensors coupled to the first component in proximity of the magnetically hard layer to sense the magnetized regions while the second component is moving with respect to the first component, at least two of the magnetic-field sensors being axially positioned to sense the same set of magnetized regions in succession and to generate signals in response to the sensed magnetized regions that can be used to determine a position of the second component;
• and
• a power source supplying electrical power to the plurality of magnetic field sensors and associated read-head electronics when equipment integrated with the components is off so that the magnetic field sensors can sense movement of the second component with respect to the first component while the equipment is off.

A position-sensing system, comprising:

• a first component;
• a second component movably coupled to the first component for movement with respect thereto;
• a magnetically hard layer formed on the second component to provide a recording medium, a plurality of regions of the magnetically hard layer being magnetized to provide an encoding scheme for determining a position of the second component relative to the first component;
• and
• a plurality of magnetic-field sensors coupled to the first component in proximity of the magnetically hard layer to sense the magnetized regions while the second component is moving with respect to the first component, at least two of the magnetic-field sensors being axially positioned to sense the same set of magnetized regions in succession and to generate signals in response to the sensed magnetized regions that can be used to determine a position of the second component;
• and
• a write head, integrated with the plurality of magnetic-field sensors, for repairing damaged or erased magnetically recorded regions.

A method for sensing a position of a first component moving relative to a second component, the method comprising:

• forming a magnetically hard layer on the first component to provide a recording medium for storing information;
• magnetically recording information at a plurality of regions of the magnetically hard layer along a direction of motion of the first component;
• reading, by a plurality of magnetic field sensors, the same magnetically recorded regions of the magnetically hard layer while the first component is moving relative to the second component;
• generating output signals by the plurality of magnetic field sensors from which a position of the first component with respect to the second component can be determined;
• and
• sensing a damaged or erased magnetically recorded region and dynamically repairing this region.

A method for sensing a position of a first component moving relative to a second component, the method comprising:

• forming a magnetically hard layer on the first component to provide a recording medium for storing information;
• magnetically recording information at a plurality of regions of the magnetically hard layer along a direction of motion of the first component;
• magnetically recording information at a second plurality of regions of the magnetically hard layer to provide an absolute measurement associated with movement of the first component;
• reading, by a plurality of magnetic field sensors, a same set of magnetically recorded regions of the magnetically hard layer while the first component is moving relative to the second component;
• and
• generating output signals by the plurality of magnetic field sensors from which a position of the first component with respect to the second component can be determined.