Hall effect position sensing in a powered parking brake system
AssigneeDelphi Technologies, Inc.
InventorsMichael C. Pfeil, Gary C. Fulks, Douglas E. Poole
Life of this patent
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Abstract
A linear position sensor that includes a plurality of Hall effect transducers enables reliable positioning of a parking brake cable. Coarse positioning sensing is provided by longitudinally spacing the Hall effect transducers such that not more than one transducer has a positively sloped output signal for a given position of a magnet connected to a parking brake cable actuator. Fine position sensing is provided by linear approximation of the output signal with an offset appropriate for the specific transducer having the sensed positively sloped output signal.
Claims13
A method of determining a linear position of an actuator in a parking brake system using a plurality of Hall effect transducers mounted proximate to a magnet coupled for linear movement with the actuator, each Hall effect transducer being longitudinally spaced from each other such that not more than one transducer produces output signals having increasing amplitude at a particular time during movement of the actuator, the method comprising:
- sensing a first plurality of output signals respectively from the plurality of Hall effect transducers;
- a second plurality of output signals respectively from the plurality of Hall effect transducers in response to movement of the actuator;
- and
- determining a coarse linear position of the actuator by comparing each first with the corresponding second output signal of the respective plurality of Hall effect transducers, and setting the coarse position of the actuator to a position value associated with the one Hall effect transducer that produces output signals having increasing amplitude during movement of the actuator.
A position sensor for determining a linear position of a powered parking brake mechanism, comprising:
- a magnet coupled for linear movement with the powered parking brake mechanism to a position along a longitudinal range;
- a plurality of Hall effect transducers aligned proximate to the longitudinal range of the magnet, each Hall effect transducer being longitudinally spaced from each other such that not more than one transducer produces output signals having increasing amplitude at a particular time during movement of the magnet;
- and
- a controller responsive to the output signals produced by each Hall effect transducer to determine the linear position of the magnet.
A parking brake release mechanism for powered release of a parking brake cable coupled to wheel brakes, the parking brake release mechanism comprising:
- an actuator configured to linearly position the parking brake cable;
- a magnet coupled for linear movement with the actuator along a longitudinal range;
- a plurality of Hall effect transducers aligned proximate to the longitudinal range of the magnet, each Hall effect transducer being longitudinally spaced from each other such that not more than one transducer produces output signals having increasing amplitude at a particular time during movement of the actuator;
- and
- a controller responsive to the output signals produced by each Hall effect transducer to determine the linear position of the actuator.
A method of determining a linear position of an actuator in a parking brake system using a plurality of Hall effect transducers mounted proximate to a magnet coupled for linear movement with the actuator, which Hall effect transducer being longitudinally spaced from each other such that not more than one transducer operates in a linear output range of the transducer at a particular time during movement of the actuator, the method comprising:
- sensing a first plurality of output signals respectively from the plurality of Hall effect transducers;
- sensing a second plurality of output signals respectively from the plurality of Hall effect transducers in response to movement of the actuator;
- and
- determining a coarse linear position of the actuator by comparing each first with the corresponding second output signal of the respective plurality of Hall effect transducers, and setting the coarse position of the actuator to a position value associated with the one Hall effect transducer that is operating in its linear output range during movement of the actuator.
Dependencies are inferred from the claim text.