Patent ID: 8004434
Filing Date: 2011-08-23
Classification: H03M

Abstract:
1. An RD converter that converts a detection angle θ indicated by resolver signals S 1 and S 2 output from a one phase excitation/two phase output resolver into a digital output angle θ′, comprising: a first multiplier that multiplies said resolver signal S a second multiplier that multiplies said resolver signal S a subtractor that subtracts an output of said first multiplier from an output of said second multiplier; a synchronous detecting circuit that synchronously detects an output of said subtractor with reference to an excitation signal; a controller that controls said digital output angle θ′ to make an output of said synchronous detecting circuit equal to zero and outputs the controlled digital output angle θ′; a correction data part that receives said digital output angle θ′ and outputs a correction angle for the digital output angle θ′; an adder that adds said digital output angle θ′ and said correction angle and outputs the sum to said SIN ROM and said COS ROM; said SIN ROM that produces a sine value of said sum and outputs the sine value; and said COS ROM that produces a cosine value of said sum and outputs the cosine value; wherein said correction data part: stores amplitudes and phases of an angle error of a fundamental frequency component and an integral multiple frequency component of the number of revolutions of said resolver, produces a fundamental frequency cosine wave and an integral multiple frequency cosine wave of said input digital output angle θ′ based on the amplitude and the phase, and outputs the sum of the cosine waves as said correction angle.