Development of A Fixed-Wing mini UAV with Transitioning Flight Capability

Abstract

This study presents the development of the transitioning vehicle Cyclone, which has been specifically designed for meteorological and agricultural applications. The mission requirements demand takeoff and landing from a small area and the ability to cope with high wind speeds. In contrast with recent suggestions, our proposed design aims to be closer to a fixed-wing airplane rather than a rotary wing. In particular, the design focuses on a tiltbody style transitioning vehicle with blown-wing concept. The propeller wing interaction is calculated using a semi-empirical method. The total wing span and wing surface area are decided according to the mission performance requirements. For the control of the vehicle, incremental nonlinear dynamic inversion is used. This control method does not need the modeling of external forces or moments and is able to counteract the strong aerodynamic forces and moments acting on the vehicle through the feedback of its angular acceleration. Together with the design phases and manufacturing process, several test flights are presented. Particular difficulties of the proposed design are discussed, including lack of providing sufficient pitch-up moment and control reversal during descent. The test flights demonstrate the vertical takeoff and landing capabilities of the vehicle, as well as its transitioning into forward flight from hovering, and vice versa, for an efficient mission performance.

Incremental Control and Guidance of Hybrid Aircraft Applied to a Tailsitter Unmanned Air Vehicle

“…The skin has a sandwich structure of aramid and glass fiber, cured in CNC machined aluminum molds, and the total mass of the vehicle is about 1.2 kg. More information on the construction process can be found in our previous publication [3]. Figure 24: A high quality build of the Cyclone.…”

“…Maintaining wing borne flight when possible can save a significant amount of energy, for instance when the vehicle is in forward flight and is required to turn around. This paper is an extension to the work presented at the AIAA Aviation Forum [3], which is about the design, manufacturing and some of the INDI control aspects of the Cyclone tailsitter MAV. The current work is dedicated to the control strategy, and goes much more in depth.…”

Modeling the unstable DelftaCopter vertical take-off and landing tailsitter unmanned air vehicle in hover and forward flight from flight test data

“…Similarly, when both propellers are in-plane but side by side, the gyroscopic effect of both counter-rotating propellers cancel each other out pretty well. This was for instance shown in the control of the MAVION by Lustosa et al 8 and the Cyclone by Bronz et al 9 Wong et al 10 have proposed a similar concept but with variable pitch propellers, and show that a controller based on a simple second-order model achieves acceptable control. But for all three, the biggest difficulty was coping with the highly non-linear and imprecisely modeled effectiveness of the aerodynamic control surfaces.…”

Model-free control algorithms for micro air vehicles with transitioning flight capabilities

“…Various studies have improved and assessed the aerodynamic properties of hybrid MAVs previously. 5,6 A critical point is the design of flap effectiveness which needs to be optimized in order to create sufficient pitch moment ensuring the control authority during transitioning flights. We focus this research project in the design and control of tailsitter MAVs, and we investigate the performance of this peculiar MAV class for three reasons: (1) Tailsitters have a better endurance in forward flight when compared to other configurations of hybrid MAVs; (2) The simple transition mechanism of tailsitters facilitates the control design for its entire flight envelope, unlike to tiltrotors that need additional actuators to orient the propeller in order to perform transitioning flights; (3) The design of controllers requiring little prior knowledge of the dynamics of tailsitter MAVs remains an attractive, motivating and challenging topic that needs to be answered by the control community.…”