Microflex Attitude and Heading Reference System

The author describes the Microflex attitude and heading reference system (MAHRS) which is an all attitude system that provides outputs of magnetic heading, pitch and roll attitude, aircraft body rates and accelerations, together with their associated validity status. It is a full strapdown system utilising two Microflex two axis rate gyroscopes, three force feedback linear accelerometers and a three axis magnetic sensor. The Microflex gyroscope provides a wide dynamic range from a few degrees/hr drift to in excess of 300 degrees/sec., by skewing the sensing axes, roll rates in excess of 400 degrees/sec can be measured. Each sensor provides two axes of rate information from a forced feedback closed loop system, that rate output being the analogue voltage developed by the torquer restoring current across a precision resistor