High resolution angular inductive sensor and associated method of use

A method for determining an angular position of a rotatable inductive coupling element, the method comprising:

• establishing a magnetic coupling in a first annular sensor, the first annular sensor comprising a first planar excitation coil and a first planar sensing coil pair, the first planar sensing coil pair comprising a respective cosine sensing coil and a respective sine sensing coil, each of the respective cosine sensing coil and the respective sine sensing coil of the first planar sensing coil pair comprising a respective clockwise winding portion and a respective counter-clockwise winding portion;
• establishing a magnetic coupling in a second annular sensor, the second annular sensor comprising a second planar excitation coil and a second planar sensing coil pair, wherein the second annular sensor is positioned to surround the first annular sensor, the second planar sensing coil pair comprising a respective cosine sensing coil and a respective sine sensing coil, each of the cosine sensing coil and the sine sensing coil of the second planar sensing coil pair comprising a respective clockwise winding portion and a respective counter-clockwise winding portion;
• positioning a rotatable inductive coupling element in overlying relation to, and separated from the first annular sensor and the second annular sensor, the rotatable inductive coupling element comprising a first annular portion comprising at least one annular conductive sector and at least one annular non-conductive sector and a second annular portion comprising at least one annular conductive sector and at least one annular non-conductive sector, and wherein a number of annular conductive sectors of the second annular portion is different than a number of annular conductive sectors of the first annular portion;
• rotating the rotatable inductive coupling element to generate coarse resolution sine and cosine signals having a number of cycles per rotation of the rotatable inductive coupling element equal to a number of annular conductive sectors of a first one of the first annular portion and the second annular portion of the rotatable inductive coupling element and to generate fine resolution sine and cosine signals having a number of cycles per rotation of the rotatable inductive coupling element equal to a number of annular conductive sectors of a second one of the first annular portion and the second annular portion of the rotatable inductive coupling element;
• and
• determining an angular position of the rotatable inductive coupling element using the coarse resolution sine and cosine signals and the fine resolution sine and cosine signals.

A method for determining an angular position of a rotatable inductive coupling element, the method comprising:

• establishing a magnetic coupling in a first annular sensor, the first annular sensor comprising a first planar excitation coil and a first planar sensing coil pair positioned within a circular interior area formed by the first planar excitation coil, the first planar sensing coil pair comprising a respective cosine sensing coil and a respective sine sensing coil, each of the respective cosine sensing coil and the respective sine sensing coil of the first planar sensing coil pair comprising a respective clockwise winding portion and a respective counter-clockwise winding portion;
• establishing a magnetic coupling in a second annular sensor, the second annular sensor comprising a second planar excitation coil and a second planar sensing coil pair positioned with a circular interior area formed by the second planar excitation coil, wherein the second annular sensor is positioned to surround the first annular sensor, the second planar sensing coil pair comprising a respective cosine sensing coil and a respective sine sensing coil, each of the cosine sensing coil and the sine sensing coil of the second planar sensing coil pair comprising a respective clockwise winding portion and a respective counter-clockwise winding portion;
• positioning a rotatable inductive coupling element in overlying relation to, and separated from the first annular sensor and the second annular sensor, the rotatable inductive coupling element comprising a first annular portion comprising at least one annular conductive sector and at least one annular non-conductive sector and a second annular portion comprising at least one annular conductive sector and at least one annular non-conductive sector, and wherein a number of annular conductive sectors of the second annular portion is different than a number of annular conductive sectors of the first annular portion;
• rotating the rotatable inductive coupling element to generate coarse resolution sine and cosine signals having a number of cycles per rotation of the rotatable inductive coupling element equal to a number of annular conductive sectors of a first one of the first annular portion and the second annular portion of the rotatable inductive coupling element and to generate fine resolution sine and cosine signals having a number of cycles per rotation of the rotatable inductive coupling element equal to a number of annular conductive sectors of a second one of the first annular portion and the second annular portion of the rotatable inductive coupling element;
• and
• determining an angular position of the rotatable inductive coupling element using the coarse resolution sine and cosine signals and the fine resolution sine and cosine signals.