Absolute encoder
AssigneeEdward L. Thies
InventorsEdward L. Thies, William F. Dowis
Life of this patent
Estimating the term…
Abstract
A non-contact absolute encoder for determining the absolute position of a movable workpiece includes a movable transducer element adapted to be coupled to the workpiece, and a sensor positioned proximate the transducer element. The encoder may be of either the rotary or linear type. The transducer element includes a characteristic profile that varies substantially continuously as a function of the transducer position. The characteristic profile may be magnetic, optical, or some other characteristic that is measurable by a non-contact sensor and is representative of transducer position.
Claims10
An absolute encoder for determining the position of a movable workpiece including a rotationally driven element, said absolute encoder comprising:
- a movable transducer element adapted for coupling to said rotationally driven element, said transducer element having a characteristic profile that varies substantially continuously as a function of the angular position of said transducer element;
- a fixed sensor positioned to sense said characteristic profile to produce a substantially continuous output signal representative of the angular position of said transducer element;
- and
- wherein said characteristic profile varies substantially continuously from a minimum value at a first angular reference position through substantially 360° to a maximum value at a second angular reference position.
An absolute encoder for determining the position of a movable workpiece including a rotationally driven element, said absolute encoder comprising:
- a movable transducer element adapted for coupling to said rotationally driven element, said transducer element having characteristic profile comprising a magnetic field strength profile that varies substantially continuously as a function of the angular position of said transducer element;
- a fixed sensor positioned to sense said characteristic profile to produce a substantially continuous output signal representative of the angular position of said transducer element;
- said transducer element further defining an axis of rotation and comprising an annular cylindrical magnetic portion having a longitudinal axis parallel to said axis of rotation, said magnetic portion having an axially oriented magnetic field, said magnetic portion defining an axially oriented surface that varies continuously in an axial direction as a function of angular position of said transducer element;
- and
- said sensor is mounted axially proximate said axially oriented surface so that said axially oriented surface and said sensor define a continuously variable air gap therebetween.
An absolute encoder for determining the position of a movable workpiece including a rotationally driven element, said absolute encoder comprising:
- a movable transducer element adapted for coupling to said rotationally driven element, said transducer element having a characteristic profile comprising a magnetic field strength profile that varies substantially continuously as a function of the angular position of said transducer element;
- a fixed sensor positioned to sense said characteristic profile to produce a substantially continuous output signal representative of the angular position of said transducer element;
- and
- said transducer element further defining an axis of rotation and comprising a disk-shaped magnetic portion having a longitudinal axis parallel to said axis of rotation, said magnetic portion having a radially oriented magnetic field, said magnetic portion defining a radially oriented surface that varies continuously in a radial direction as a function of angular position of said drive shaft;
- and
- sensor is mounted radially proximate said radially oriented surface so that said radially oriented surface and said sensor define a continuously variable air gap therebetween.
An absolute encoder for determining the position of a movable workpiece including a linearly driven element, said absolute encoder comprising:
- a movable transducer element adapted for coupling to said linearly driven element, said transducer element having a characteristic profile comprising a magnetic field strength profile that varies substantially continuously as a function of the linear position of said transducer element;
- a fixed sensor positioned to sense said characteristic profile to produce a substantially continuous output signal representative of the linear position of said transducer element;
- said transducer element defining an axis of translation and comprising a magnetic portion having a longitudinal axis parallel to said axis of translation, said magnetic portion having a magnetic field oriented in a first direction transverse to said longitudinal axis, said magnetic portion defining a surface oriented in said first direction that varies substantially continuously in said first direction as a function of linear position of said transducer element;
- and
- said sensor is mounted proximate said magnetic portion surface so as to define a continuously variable air gap therebetween.
An absolute encoder for determining the position of a movable workpiece, said absolute encoder comprising:
- a transducer element coupled to said workpiece for movement with said workpiece, said transducer element having a characteristic profile comprising a predetermined magnetic field strength profile that varies substantially continuously as a function of position along said transducer element;
- a fixed sensor positioned to sense said characteristic profile to produce a substantially continuous output signal representative of the position of said transducer element relative to said sensor;
- and
- wherein said sensor is mounted proximate a movable surface of said transducer element so that said sensor senses a continuously variable magnetic field intensity received from said transducer element, the magnetic field intensity received by said sensor indicating a position of said transducer relative to said sensor.
Dependencies are inferred from the claim text.