Patent ID: 7187309

Claim:
An angle computation method for a VR resolver comprising: a step a of acquiring an output voltage V sin of a SIN voltage output coil of the resolver and an output voltage V cos of a COS voltage output coil of the resolver, and extracting the maximum value V sin (max) of the output voltage V sin within a range in which the output voltage V sin assumes a positive value, the maximum value V cos (max) of the output voltage V cos within a range in which the output voltage V cos assumes a positive value, the minimum value V sin (min) of the output voltage V sin within a range in which the output voltage V sin assumes a negative value, the minimum value V cos (min) of the output voltage V cos within a range in which the output voltage V cos assumes a negative value; a step b of obtaining an offset value V SINOFFSET of the output voltage V sin from the V sin (max) and the V sin (min) in accordance with Eq. A, and obtaining an offset value V COSOFFSET of the output voltage V cos from the V cos (max) and the V cos (min) in accordance with Eq. B; and a step c of obtaining an angle θ from the output voltage V sin , the output voltage V cos , the offset value V SINOFFSET , and the offset value V COSOFFSET in accordance with Eq. C wherein V SINOFFSET =( V sin (max)+ V sin (min))/2 Eq. A, V COSOFFSET =( V cos (max)+ V cos (min))/2 Eq. B; F ( V sin −V SINOFFSET , ( V cos −V COSOFFSET ))=θ. Eq. C