Patent ID: 6426712
Filing Date: 2002-07-30
Classification: H03M

Abstract:
A method of generating at least one fault signal which indicates degraded accuracy of an estimated angle &phgr; that is generated by a servo loop in response to sense signals A1 sin &thgr; and A2 cos &thgr; that are generated by a resolver that senses a position angle &thgr; of a rotatable member, wherein each of the signal amplitudes A1 and A2 have a nominal value Anom, the method comprising the steps of:generating a monitor signal of A1 sin &thgr; sin &phgr;+A2 cos &thgr; cos &phgr;; providing a first fault signal when said monitor signal exceeds a maximum threshold THLDmax that is greater than said nominal value Anom; and providing a second fault signal when said monitor signal drops below a minimum threshold THLDmin that is less than said nominal value Anom; said fault signals thereby indicate degraded accuracy of said estimated angle &phgr;.