Development and testing of the digital control system for the Archytas Unmanned Air Vehicle

Abstract

The purpose of this study was to develop the digital sampling and control system for an Unmanned Air Vehicle (UAV) designed to takeoff and land vertically and to transition to forward flight. The system is designed to operate from a personal computer through an umbilical cable tethered to the platform for hover tests. The computer controls the sampling and digital conversion of onboard analog sensor signals and sends control-surface commands for pitch, roll and yaw motions. The thesis effort includes the following four parts: Design of a controllable Pulse-Width-Modulated signal to command the servos which operates various aerodynamic surfaces. This control is accomplished with software written to a counter/timer card installed in the computer. Sampling and conversion of the signals to the sensors through the programming of an analog-to-digital card installed in the computer. Sensor Power-up and parameter verification of onboard devices. Development of various power networds to allow operation of onboard systems prior to engine start with the ability to be self-sustaining once the engine is running. The system was fully tested during ground runs on a thrust/torque test stand. Integration of the system with the robust controller designed in a concurrent thesis will provide for the stability necessary for the innovative unmanned vehicle..