Development of a Real-time Onboard and Ground Station Software System for a UAV Helicopter

Abstract

We report in this paper the development of a real-time software system for an unmanned aerial vehicle (UAV) helicopter, which consists of an embedded computer onboard and a ground station served by a laptop. The software system for the onboard computer performs multiple tasks including data acquisition and measurement, servo driving, automatic flight control implementation, communications and data logging. The system for the ground station gives a flexible graphical interface monitoring the real-time status of the UAV helicopter. We present the frameworks and structures of the onboard and ground station systems. The onboard system employs a framework of multiple task threads with each thread being assigned to perform a specific task. Management and time scheduling for task threads together with the detailed implementation of automatic flight control laws are the main focuses of the onboard software system. A behavior-based architecture is designed to address task scheduling and event disposal for automatic control. A hierarchical and componential structure is developed to integrate multiple control laws and perform various helicopter behaviors. The ground station software system employs a two-layer framework, i.e., data transferring in background and data visualization in foreground.A variety of views are developed to display in-flight data received from the UAV helicopter in different forms including a 3D monitoring panel, which displays real-time data in 3D on the ground station.