Minimizing magnetic interference in a variable reluctance resolver

Abstract

A resolver apparatus and method are provided. The apparatus comprises a source generation unit for generating a uni-phase source signal to excite a resolver, wherein said source generation unit comprises a low distortion oscillator, a variable phase shifter, and a capacitive resolver driving network; and a signal output unit for generating a two-phase output signal, wherein said signal output unit comprises the resolver, a signal detector and level adjuster, an angular position measurement unit, and an angular position compensation unit. The method comprises generating a source signal to excite a resolver; transmitting the source signal through a variable phase shifter; transmitting the source signal through at least one capacitive passive element serially connected to each coil winding of the resolver; outputting a displacement signal generated by the resolver to a resolver-to-digital converter; and converting said displacement signal into a digital position using the resolver-to-digital converter.

1 . A method for minimizing magnetic interference in a resolver, the method comprising:
 generating a uni-phase source signal to excite a variable reluctance (VR) resolver,   wherein the source signal is transmitted through at least one capacitive passive element serially connected to each coil winding of the VR resolver,   wherein a two-phase displacement signal generated by the VR resolver is outputted to a resolver-to-digital converter, and   wherein the displacement signal is converted into a digital position using the resolver-to-digital converter.   
     
     
         2 . The method of  claim 1 , wherein amplitude and phase of the source signal is controlled by connecting at least one resistive passive element in parallel with said capacitive passive element. 
     
     
         3 . The method of  claim 1 , wherein the source signal is phase shifted using a variable phase shifter. 
     
     
         4 . An apparatus for minimizing magnetic interference in a resolver, the apparatus comprising:
 a source generation unit for generating a uni-phase source signal to excite a variable reluctance (VR) resolver, said source generation unit comprising a low distortion oscillator, a variable phase shifter, and a capacitive resolver driving network comprising at least one capacitive passive element connected to each coil winding of the VR resolver; and   a signal output unit for generating a two-phase output signal, said signal output unit comprising the VR resolver, a signal detector and level adjuster, an angular position measurement unit, and an angular position compensation unit.   
     
     
         5 . The apparatus of  claim 4 , wherein at least one resistive passive element is connected in parallel with said capacitive passive element in order to reduce angle displacement measurement error by controlling amplitude and phase of the source signal. 
     
     
         6 . The apparatus of  claim 4 , wherein the capacitive passive element is serially connected to each coil winding of the VR resolver. 
     
     
         7 . The apparatus of  claim 6 , wherein at least one resistive passive element is connected in parallel with the capacitive passive element.