Patent ID: 7426859
Filing Date: 2008-09-23
Classification: G01C,G01P

Abstract:
1. A motion sensor comprising: a reference structure; a free-floating rotor constructed and arranged to rotate about an axis relative to the reference structure and to be free from contact with the reference structure; a plurality of electrodes supported by the reference structure, the electrodes being positioned adjacent at least top, bottom and side surfaces of the free-floating rotor; and circuitry that detects movement of the reference structure relative to the free-floating rotor, the circuitry positioning the free-floating rotor relative to the reference structure using a force-balanced control of at least one pair of the electrodes, the force-balanced control operating to determine control signals to be provided to each of the electrodes in the pair to exert forces on the free-floating rotor to keep the free-floating rotor in a desired position relative to the reference structure and without calculating displacement of the free-floating rotor relative to the reference structure.