A Low-Cost, Redundant Inertial Measurement Unit for Unmanned Air Vehicles

This paper discusses the development of a low-cost, redundant, strapdown inertial measurement unit (IMU). The unit comprises four ceramic vibrating structure gyroscopes and four QLC 400 accelerometers configured on a truncated tetrahedron design. This design allows for the optimal configuration of the eight sensors, which in turn provides for a theoretical 33% increase in information. The redundant sensor configuration also allows for fault detection, which is required for many autonomous applications. This initiative is a precursor for future developments with more sensors to provide fault isolation. The paper will also present a navigation system implementing the redundant IMU with the global positioning system. Results are provided of this navigation system being implemented in an unmanned air vehicle. KEY WORDS—inertial measurement unit, redundancy, global positioning system, information filter, autonomous systems, UAV