Importance

Loading Importance Indicators...

Abstract

Method for the determination of the position angle of a capacitive motion encoder (1) for sensing the position of a rotor (6) relative to a stator (2, 37) comprising an eccentric rotor disk (6, 7) relatively movable to a stationary stator (2, 37) with four electrical isolated field transmitters (4a, 4b, 4c, 4d; 38a-d) which generate an electrostatic field in a receiver area (5) which is modulated by a change in capacitance between the stator (2, 37) and rotor disk (6, 7) response to relative motion of the elements; and a processing circuitry (49) coupled to sense the modulated electrostatical field and determine responsive thereto a measure of the position of a moving object, characterized in that within one cyclic measurement time (10) at least 8 measurements (11 through 18) are carried out defining at least 8 different capacitance values (C1, C2, C3, C4, C4′, C3′, C2′, C1′) where the first capacitor C1 is measured in the 1st and 8th cycle, the second capacitor C2 is measured in the 2nd and 7th cycle, the third capacitor C3 is measured in the 3rd and 6th cycle, and the fourth capacitor C4 is measured in the 4th and 5th cycle.

Loading the Abstract Image...

First Claim