Patent ID: 7430460

Claim:
A method for correcting a bias of a roll rate gyro utilized in an Attitude and Heading Reference System, said method comprising: (a) monitoring the heading rate of an aircraft; (b) monitoring at least the lateral and vertical body accelerations of the aircraft; (c) monitoring the true airspeed of the aircraft; (d) calculating a bank angle from the above using centripetal force equations; (e) comparing said calculated bank angle with the bank angle derived from integrating the output of said roll rate gyro; and (f) when the aircraft is flying in a low-dynamic state, adjusting said bias so that the bank angle derived from integrating the output of said roll rate gyro converges with the bank angle calculated from the centripetal force equations; and (g) using the bias adjusted bank angle to erect the attitude and heading reference system while the aircraft is flying.