Estimating Attitude of a Robotic Balloon From Accelerations

An improved "sensor-integrating" algorithm has been developed for use in extracting partial information on the time-varying attitude of a balloon-borne robotic instrumentation system from the outputs of accelerometers that measure accelerations along three Cartesian axes fixed in the instrument package. The partial attitude information in question comprises two coordinates, representing angles of rotation of the instrument package about two orthogonal horizontal axes. If a single additional vector measurement (e.g., the direction to the Sun) is available, then all three angular coordinates are known; that is, the attitude is fully characterized. Because the algorithm could make it unnecessary to carry a complement of conventional high-precision attitude-measuring instrumentation, it affords potential for reducing the sizes, weights, and costs of meteorological, military, planetary exploration, and other balloon-borne robotic instrumentation systems.