Implementation of an Attitude-heading Reference System State Estimate Filter Using Dissimilar Sensor Types and Sampling Rates

Domestic production of general aviation (GA) aircraft has declined markedly in recent years and an effort is underway to revitalize this industry by opening new markets for aviation, shifting the perception of general aviation as recreation to general aviation as a travel option. This can be achieved only by providing a product that is safer, easier to fly in all weather conditions, and no more expensive than today’s low end general aviation aircraft. The critical path to this goal is the development of an inexpensive yet reliable advanced flight system, incorporating various levels of automation and control augmentation to simplify the operation of the aircraft. One key element in the control of an aircraft is the ability to accurately deduce the aircraft’s attitude and angular velocity. The work reported in this paper describes the development of a state estimate filter to accept measurements from dissimilar sensor types sampled at different rates and produce a quasi-continuous best estimate of the vehicle attitude and angular velocity. A novel configuration incorporating Global Positioning System based sensors, inexpensive tuning fork gyros, and distributed accelerometers has been developed. This paper extends the theoretical work presented previously at the IASTED International Conference on Control and Applications, 1998. It describes the hardware implementation of the system and discusses the validation testing procedure.