The paper presents the heavy lifting modification of radio controlled T-Rex 700 DFC PRO helicopter which was originally designed as acrobatic machine. The purpose of designing machine like this is a need for a cheap and reliable machine specifically designed to carry weights for research and development purposes. Thanks to its design there is a possibility to attach to it a measuring apparatus, modules like auto-pilot, and weights. It can be also used to test wide range of rotors and other components which makes it very universal research tool. To achieve those goals the whole frame and landing gear has been redesigned using NX 11 CAD/CAM/CAE to achieve desired cargo space and weight distribution. Additionally the tail has been lengthened to allow use of the rotors with bigger diagonal. All the applied changes has been made to increase the machine payload. The designed elements were fabricated and the helicopter has been tested in flight. During the test flights several performance parameters were measured.
Reliability of unmanned aircraft is a decisive factor for conducting air tasks in a controlled airspace. One of the means of improving unmanned aircraft reliability is reconfiguration of the control system, which will allow to maintain control over the aircraft despite an occurring failure. The control system is reconfigured by using still operational control surfaces to compensate for failure consequences and to control the damaged aircraft. Development of effective reconfiguration algorithms involves utilization of a non-linear model of unmanned aircraft dynamics, in which each control surface deflection can be controlled independently.
The paper describes a non-linear model of a small unmanned aircraft with decoupled control surfaces. The paper discusses aircraft flight dynamics equations and estimated equations for controllability derivatives for each control surface, the results of comparison tests of the model and actual aircraft as well as the structure of the simulation model. The developed unmanned aircraft model may be used in development and in optimization of control algorithms for aircraft with damaged control systems as well as to test the impact of failures on dynamic properties of the aircraft.