A Novel Design Method for Resolver-to-Digital Conversion

A simple and novel design method for resolver-to-digital conversion is presented. The proposed method takes advantage of the auxiliary sinusoidal signals generated by addition and subtraction operations of the demodulated signals of the resolver's outputs. A pseudolinear signal is obtained through appropriate mathematical manipulation between the auxiliary sinusoidal signals and the demodulated ones. A calibration strategy is then provided to achieve the highest possible precision. It is shown that the error between the calibrated angular and the true angular position is less than 0.00235° over 0° ~ 360°. The proposed method enables the determination of the angular position without utilizing a lookup table or additional reference signals. Furthermore, the presented strategy is implemented using a field-programmable gate array. Finally, our method is tested on a tracking radar antenna servo system where resolvers are installed on it. Several experiments under different conditions are performed to further verify the effectiveness of the proposed method.