Patent ID: 8427141

Claim:
A method to determine a relative position (ρ) of a resolver comprising the steps of: exciting an exciter winding of a resolver with a reference signal U(t); sampling a first signal U S1 (t) resulting from the reference signal in a first winding of the resolver and sampling a second signal U S2 (t) resulting from the reference signal in a second winding of the resolver; in a processor, determining an uncompensated Fourier coefficient z S1 for the first signal U S1 (t) and an uncompensated Fourier coefficient z S2 for the second signal U S2 (t); and in said processor, determining a compensated Fourier coefficient z S1,com for the first signal U S1 (t) and a compensated Fourier coefficient Z S2,com for the second signal U S2 (t) that essentially compensate a change of the uncompensated Fourier coefficients z S1 , z S2 that is due to at least one of a phase shift of the resolver and a change of the relative position during said sampling.