small Unmanned Aerial Systems (sUAS) research projects
The group carries out all forms of research activities to do with civilian fixed wing sUAS performing low altitude long endurance (LALE) missions in non-segregated airspace. The activities are multi-disciplinary in nature, and involve the combination of control, smart material active actuation and aero and thermodynamics. The current projects of interest include, but are not limited to as follows:
- Hybrid air vehicles
The group is looking at the flight dynamics and control of aerofoil shaped, inflatable wing hybrid air vehicles for low altitude ultra-long endurance (LAuLE) civilian unmanned systems. These are not lighter than air vehicles and have only a buoyancy assist capability from the gas enclosed within the structure. Due to the external structure being non-rigid, they may not have an exact aerofoil shape. Using advanced control and smart material actuation, the objective of this research track is to enhance the performance and robustness of such platforms.
- Collision avoidance
The main thrust of our research is collision avoidance of our fixed wing civilian sUAS for non-cooperative flying platforms as part of civilian air traffic management (AMT). We consider all form of hazards to UAVs such as balloons, gliders, parachutists and light aircraft without electronic collision detect and avoid systems. This to address a void left by current collision avoidance algorithms which focus more on multirotors, geofencing, fixed obstacle avoidance and cooperative (formation flight) collision avoidance, which has less stringent constraints in terms of eventual embedded applications.
- Optimisation of dynamic soaring
We intend to combine morphing wing technology for dynamic soaring flight profiles for LALE operations. This track involves simulation, wind tunnel and open air investigative test for active control morphing wings which can optimise dynamic soaring flight profiles.
- Fuel sloshing in sUAS
Most LALE fixed wing sUAS would carry a very high fuel load fraction which can result in sloshing of fuel in the fuel tanks. This in turn can result in a number of dynamic disturbances. Data from larger civilian aircraft are very often not applicable for sUAS due to a differing performance envelope. This track requires the investigator to be multi-disciplinary in areas of solid-fluid interaction and embedded control theory.
- Small IC engine efficiency
In collaboration with our gas and petroleum department, we are investigating the efficiency and environmental impact of sUAS engines. The objective is to carry out complete parametric study of commercial-off-the –shelf COTS engines currently designed for large hobby aeromodels and tune them for efficient and environmentally friendly LALE operations. Areas include combustion efficiency of propulsion systems, after market fuel injection control and alternative fuel utilisation.
- Quasi-3D aerodynamic modelling
The aerodynamic performance of fixed wing sUAS can be determined using either Computational Fluid Dynamics (CFD) or low-fidelity models such as the Lifting-Line Theory (LLT) or the Vortex Lattice Method (VLM). The CFD approach gives accurate results at the cost of very high computational time, while the low-fidelity models provide immediate results at the cost of reduced accuracy. This research track aims to bridge the gap between the two approaches, by combining the low-fidelity models with 2D aerofoil results (experimental or CFD) into quasi-3D aerodynamic models.
- sUAS design optimisation
We intend to maximize the performance of LALE designs by aerodynamically optimising the lifting surfaces to achieve the highest possible lift-to-drag ratios at a given sUAS mass. This research track involves aerofoil modification and/or design, iterative wing design using optimisation algorithms, the use of morphing wing technology to actively modify the wing shape as function of the flight conditions.
Some of our project examples:
Enhanced safety and reliability for trains through fault tolerant control
High integrity actuation system with embedded intelligence