Patent ID: 8004277
Filing Date: 2011-08-23
Classification: B62D,G01D

Abstract:
1. An angular position sensor, comprising: a shaft having a threaded portion, and a structure for engaging an external application that involves rotation of a rotatable member, said rotation of said rotatable member rotating said shaft, wherein said shaft includes a first permanent magnet; a nut having threading threaded on said threaded portion; wherein said nut is formed from a first magnetic permeable material or comprises a second permanent magnet; at least one constraint coupled to said nut for preventing rotational movement of said nut while allowing linear motion of said nut; a first magnetic sensor positioned along a length of said threaded portion of said nut for measuring a linear position of said nut; a second magnetic sensor for measuring an angular position of said shaft, and signal processing circuitry coupled to receive respective outputs from said first magnetic sensor and said second magnetic sensor for calculating a parameter relating to an angular position of said rotatable member, wherein said parameter comprises a turn count, and wherein said microcontroller derives a course measured position portion comprising an integer number of turns of said turn count from said linear position of said nut provided by said first magnetic sensor and a fine measured position portion fractional portion of said turn count from said angular position of said shaft from said second magnetic sensor.