Low-cost avionics for autonomous navigation software/hardware testing

This work presents the engineering process for implementing avionics of a mini unmanned aerial vehicle developed for autonomous navigation in-flight tests at the University of Naples. First of all, the design requirements are introduced. They are driven by costs, by onboard resources, and by attainable accuracy in the determination of the state vector. Subsequently, the selection of system components is discussed. These are the onboard processing unit, the inertial navigation unit, the GPS receiver, and the radio link. System control logic is fully reported in the paper. Several operating modes have been implemented depending on the adopted navigation algorithms. In particular, multiple inertial aiding techniques adopted are addressed. The fusion of data from more than two sensors is needed to attain the requested levels of accuracy and reliability during critical mission phases such as takeoff and landing. Finally, the accuracy in the full state vector determination is reported. It was on the order of 10 meters in position and 0.1° in attitude for the GPS/inertial integrated system available whereas vertical position accuracy results were better than 1 meter if an additional altimeter is adopted. This operational mode is required for the landing phase.