Patent ID: 7565260

Claim:
An apparatus for setting a gyroscope zero point reference value, comprising: a gyroscope for outputting a signal indicating angular velocity in the form of a voltage; a global positioning system (GPS) receiver for receiving a GPS signal; an analog-to-digital (A/D) converter for digitizing the voltage output from the gyroscope; and a controller for detecting a speed and a direction angle of a vehicle from the received GPS signal, determining if the vehicle is traveling in a straight line, and filtering the voltage output from the gyroscope to obtain a gyroscope zero point reference value if the vehicle is traveling in the straight line, wherein the gyroscope zero point reference value is computed by ZPT_Ref=(N−1)/N*ZPT_Ref+1/N*Mean(Y[ 0 . . . 9 ]), where ZPT_Ref denotes a gyroscope zero point reference value, N denotes a smoothing filter constant, and Mean(Y[ 0 . . . 9 ]) denotes a mean value of Y[ 0 ] to Y[ 9 ] values, each of the Y[ 0 ] to Y[ 9 ] values being an average of an accumulated value obtained by accumulating a mean value of gyroscope output values measured in a predetermined cycle a predetermined number of times.