Development of a laboratory hils testbed system for small UAV helicopters

An Unmanned Aerial Vehicle (UAV), especially helicopter, is an intricate machine which is very difficult to control. Conventional control systems are built then tested by employing long-term, costly and risky experiments by flying the real vehicle. To solve these problems, a laboratory testbed system developed with Hardware-In-The-Loop simulation (HILs) is proposed for testing and evaluating the control systems. HILs system is built up from the ground in a laboratory environment without employing a real helicopter. The hardware features used in the system enhances the realism of the simulation. HILs system allows researchers to not only reduce cost and risk but also save time and readily repeat experiments in the development of UAVs. This research presents the design and implementation of a real-time HILs system. A HILs system is comprised of a real-time simulator mimicking the motion of the flying helicopter and a control unit providing access to the real hardware features. The simulator containing the helicopter dynamic model is established by an xPC Target in Matlab/Simulink and the control unit executing the designed control laws is developed under QNX RTOS. By synchronizing the system, several experiments with different scenarios have been successfully performed. The results clearly indicate that HILs system is feasible and practicable. It can be an efficient tool for developing, comprehensively testing and validating flight control systems.