Attitude estimation on SO[3] based on direct inertial measurements

This paper considers the question of obtaining high quality attitude estimates from typical low cost inertial measurement units for applications in control of unmanned aerial vehicles. A nonlinear complimentary filter exploiting the structure of special orthogonal group S0(3) is proposed. The filter is expressed explicitly in terms of direct and untreated measurements. For a typical low cost inertial measurement where two inertial directions are measured (gravitational and magnetic fields) along with angular velocity, it is shown that the filter is well conditioned. If only a single direction is available (typically the gravitational field) along with angular velocity, it is shown that the full gyro bias vector is correctly estimated and that the estimated orientation converges to a set consistent with the measurements. Experimental results, for flight data from the HoverEyecopy UAV, demonstrate the efficiency of the proposed filter