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Thesis (PhD(Mechanical and Manufacturing Engineering))--University of South Australia, 2023. Includes bibliographical references (pages 211-234) Despite incremental advances, the complexity of insect flight is yet to be fully characterised, and the development of insect-inspired drones that can rival the flight performance of insects remains elusive. Studies show that some insects modify their body postures substantially during flight, yet, most insect flight studies focus on wings. This thesis investigated the effects of moving appendages on the forward flight dynamics of insects through tensor-based multibody mathematical modelling and simulation. The results were analysed using aeronautical techniques, resulting in the development of validated methods for automating the flight of such craft. The outcomes of this thesis will contribute to the development of biomimetic aircraft, and will also increase insight into observational biological results.

Electrical insulation failure is the most common failure mechanism in electrical machines (motors and generators). High temperatures and/or temperature gradients (HTTG) are the main drivers of insulation failure in electrical machines. HTTG combine with and augment other destructive effects from over-voltage, to voltage transients, overload and load variations, poor construction techniques, and thermal cycling. These operating conditions cause insulation damage that leads to electrical insulation failure. The insulation failure process is greatly accelerated by pollutants and moisture absorption. A simple and robust way to reduce HTTG and moisture adsorption is by maintaining constant internal temperatures. The current method to maintain elevated internal temperatures and reduce condensation issues is by internal electrical heating elements. This paper examines the effectiveness of applying thermoelectric coolers (TECs), solid-state heat pumps (Peltier devices), as heaters to raise a motor’s internal temperature by pumping heat into the motor core rather than heating the internal air. TEC technology is relatively new, and the application of TECs to heat a motor’s internal volume has not previously been explored. In this paper, we explore the hypothesis that TECs can pump heat into a motor when out of service, reducing the HTTG by maintaining high winding slot temperatures and eliminating condensation issues. This paper describes a test motor setup with simple resistive heating (traditional method), compared with the application of TECs with heat sinks, heat pipes, and a water circulation heat exchanger, to gauge the capability of TECs to heat the inner core or winding area. In this paper, we demonstrate the full integration of TECs into a motor. The results show that each of the systems incorporating the TECs would effectively pump heat into the core and keep the winding hot, eliminating condensation issues and water ingress due to thermal cycling. Refereed/Peer-reviewed

Refereed/Peer-reviewed Flapping wing systems are being developed by various institutions and research groups around the world with many systems developed that are capable of full flight. However, while instrumentation has been developed that is capable of measuring some of the characteristics of these systems, there is no complete solution. This paper seeks to take the first step toward instrumentation that could be applied to any flapping wing system. This first step is to identify and characterize the forces that are operating on flapping wing systems. This paper presents, in premiere, a systematic analysis of all cases that can create useful or parasitic aerodynamic loads along with the other major loads that would be experienced by these cases and methodology for how these can be measured with the ambition that it can become a framework to be used to characterize any flapping wing system.

Electric motors and generators underpin life in today’s world. They are numerous and widespread and consume approximately 45% of the world’s energy. Any improvements in efficiency or reductions in their whole-of-life costs are actively and continually being sought. While designs accommodate the removal of heat caused by internal losses because of inefficiencies, temperature variations due to load changes and environmental temperature fluctuations, and system harmonic content still stresses electrical insulation systems. This causes the fretting of insulation, combined with moisture ingress, which leads to leakage currents and, consequently, the early failure of the electrical insulation. This paper explores the addition of thermoelectric coolers/heaters (TECs) or Peltier effect devices. We show that these solid-state devices can actively support the thermal management of a motor by keeping its internals hot, reducing moisture ingress when off, and assisting in heat removal when under load, resulting in a more thermally stable internal environment. A thermally stable environment inside the electrical machine reduces the mechanical stresses on the electrical insulation, resulting in a longer operational life and reducing the whole-of-life costs. Refereed/Peer-reviewed

Shape memory alloys (SMAs) have been considered as actuators for micro application due to its high strength to weight ratio. Although it is mostly considered for linear or rotary actuation, in this study a technique using a temperature feedback control system has been proposed to produce oscillation at steady state suitable for flapping wing actuation in micro air vehicles (MAVs). A proportional-integral-derivative (PID) controller was used in the temperature feedback system to tune the frequency of oscillation of the shape memory alloy actuator. This system is compact as the oscillation can be produced without using components to translate from linear to rotary motion. Another challenge to be addressed is the slow cooling rate of the SMA actuator that occurs through natural convection resulting in slower flapping actuation. Thus, a viable approach to improve the actuation response is by coating the SMA to reduce hysteresis. An experimental study was conducted to evaluate the effects of heat convection on the SMA actuator's control performance by using SMA wire coated with silicone rubber. Its actuation was compared to the uncoated SMA wire to establish the effects of heat convection on SMA actuation behaviour. The response of the temperature feedback system of the SMA actuator for the flapping actuation under wind loading was evaluated using wind tunnel testing. The experimental results show that coated SMA wire resulted in increased actuation frequency. However, this effect became negligible as the airflow provided sufficient cooling and resulted in higher flapping frequency at Reynolds number greater than 7.5 × 103. Wind tunnel testing demonstrated that shape memory alloy actuators using a PID based temperature feedback control system may be used to produce flapping actuation at low Reynolds numbers. Refereed/Peer-reviewed

Refereed/Peer-reviewed Insects use dynamic articulation and actuation of their abdomen and other appendages to augment aerodynamic flight control. These dynamic phenomena in flight serve many purposes, including maintaining balance, enhancing stability, and extending manoeuvrability. The behaviours have been observed and measured by biologists but have not been well modeled in a flight dynamics framework. Biological appendages are generally comparatively large, actuated in rotation, and serve multiple biological functions. Technological moving masses for flight control have tended to be compact, translational, internally mounted and dedicated to the task. Many flight characteristics of biological flyers far exceed any technological flyers on the same scale. Mathematical tools that support modern control techniques to explore and manage these actuator functions may unlock new opportunities to achieve agility. The compact tensor model of multibody aircraft flight dynamics developed here allows unified dynamic and aerodynamic simulation and control of bioinspired aircraft with wings and any number of idealized appendage masses. The demonstrated aircraft model was a dragonfly-like fixed-wing aircraft. The control effect of the moving abdomen was comparable to the control surfaces, with lateral abdominal motion substituting for an aerodynamic rudder to achieve coordinated turns. Vertical fuselage motion achieved the same effect as an elevator, and included potentially useful transient torque reactions both up and down. The best performance was achieved when both moving masses and control surfaces were employed in the control solution. An aircraft with fuselage actuation combined with conventional control surfaces could be managed with a modern optimal controller designed using the multibody flight dynamics model presented here.

Refereed/Peer-reviewed Commercial and industrial applications of drones are delivering very significant economic benefits to corporations and organisations utilising drones and to the economies in which they are deployed. There are also substantial and growing rewards accruing to drone manufacturers, software makers and associated commercial enterprises. However, for many the real benefits lie in the benefits to society, the humanitarian applications, the delivery of medical supplies or the pleasure of flying a drone as a hobby or sport. This chapter focuses upon the substantial contributions of drones in relation to healthcare and humanitarian efforts. It also considers their extensive use and enjoyment by the public at large in recreational environments. In these diverse contexts, they deliver benefits to society and to the community at large that augment their more commercial and industrial applications. Facilitating access to remote areas, maintaining social distancing in the COVID-19 pandemic context, monitoring health and replenishing stocks in a timely manner with medical supplies are all growing priorities for governments globally. Drones are also proving to be invaluable in improving disaster response and relief operations by helping to ensure that those operations can be conducted safer, faster and more efficiently. They are also able to assist with risk assessment, mapping and planning to reduce the impact of natural disasters when they occur. This chapter, by providing these insights, gives further context to the delicate balancing act regulators must perform to ensure that regulatory requirements imposed upon drone use are commensurate with the risks they pose and are not so heavy-handed as to stifle their deployment in areas such as the provision of medical services and disaster relief.

usc Many drone platforms have matured to become nearly optimal flying machines with only modest improvements in efficiency possible. “Chimera” craft combine fixed wing and rotary wing characteristics while being substantially less efficient than both. The increasing presence of chimeras suggests that their mix of vertical takeoff, hover, and more efficient cruise is invaluable to many end users. We discuss the opportunity for flapping wing drones inspired by large insects to perform these mixed missions. Dragonflies particularly are capable of efficiency in all modes of flight. We will explore the fundamental principles of dragonfly flight to allow for a comparison between proposed flapping wing technological solutions and a flapping wing organism. We chart one approach to achieving the next step in drone technology through systems theory and an appreciation of how biomimetics can be applied. New findings in dynamics of flapping, practical actuation technology, wing design, and flight control are presented and connected. We show that a theoretical understanding of flight systems and an appreciation of the detail of biological implementations may be key to achieving an outcome that matches the performance of natural systems. We assert that an optimal flapping wing drone, capable of efficiency in all modes of flight with high performance upon demand, might look somewhat like an abstract dragonfly. Refereed/Peer-reviewed

The World Health Organization (WHO) has declared COVID-19 a pandemic. We review and reduce the clinical literature on diagnosis of COVID-19 through symptoms that might be remotely detected as of early May 2020. Vital signs associated with respiratory distress and fever, coughing,and visible infections have been reported. Fever screening by temperature monitoring is currently popular. However, improved noncontact detection is sought. Vital signs including heart rate and respiratory rate are affected by the condition. Cough, fatigue, and visible infections are also reported as common symptoms. There are non-contact methods for measuring vital signs remotely that have been shown to have acceptable accuracy, reliability, and practicality in some settings. Each has its pros and cons and may perform well in some challenges but be inadequate in others. Our review shows that visible spectrum and thermal spectrum cameras offer the best options for truly noncontact sensing of those studied to date, thermal cameras due to their potential to measure all likely symptoms on a single camera, especially temperature, and video cameras due to their availability, cost, adaptability, and compatibility. Substantial supply chain disruptions during the pandemic and the widespread nature of the problem means that cost-effectiveness and availability are important considerations. Refereed/Peer-reviewed

A constraining factor in the development of flapping wing micro air vehicles (MAVs) is the power density and efficiency of actuators. Piezoelectric and rotary electromagnetic actuators have been shown to have functional power densities but can require mechanically complex transmissions to create flapping motion. Electromagnetic Linear actuators (ELAs) have unique characteristics, allowing them to be controlled and implemented similarly to muscles but demonstrated much lower efficiency. This study presents configurations of ELA consisting of multiple coils and magnets that have the potential to improve efficiency. The use of lightweight conductors in the form of copper clad aluminium (CCA) is explored as a method to improve power density. A numerical method of optimising the geometry and mass distribution of the magnetic and conductive material is presented. The results show the power consumption of these actuators can range between 910-260 W/kg. The inclusion of an additional magnet and coil can improve efficiency by up to 3.5 times over typical flapping wing ELAs.

The actuated abdomens of insects such as dragonflies have long been suggested to play a role in optimisation and control of flight. We have examined the effect of this type of actuation in the simplified case of a small fixed wing aircraft to determine whether energetic advantages exist in normal flight when compared to the cost of actuation using aerodynamic control surfaces. We explore the benefits the abdomen/tail might provide to balance level flight against trim changes. We also consider the transient advantage of using alternative longitudinal control effectors in a pull up flight maneuver. Results show that the articulated abdomen significantly reduces energy consumption and increase performance in isolated manoeuvres. The results also indicate a design feature that could be incorporated into small unmanned aircraft under particular circumstances. We aim to highlight behaviours that would increase flight efficiency to inform designers of micro aerial vehicles and to aid the analysis of insect flight behaviour and energetics Refereed/Peer-reviewed

This research investigates the use of a Linear Quadratic Regulator (LQR) controller to assist commercial Boeing 747-200 aircraft regains its stability in the event of damage.Damages cause an aircraft to become asymmetric and in the case of damage to a fraction(33%) of its left wing or complete loss of its vertical stabilizer, the loss of stability may lead to a fatal crash. In this study, aircraft models for the two damage scenarios previously mentioned are constructed using stability derivatives. LQR controller is used as a direct adaptive control design technique for the observable and controllable system. Dynamic stability analysis is conducted in the time domain for all systems in this study usc Refereed/Peer-reviewed