Reece Clothier | RMIT University (original) (raw)
Papers by Reece Clothier
International Journal of Micro Air Vehicles, 2015
Journal of Aircraft
Fixed-wing Micro Aerial Vehicles (MAVs) experience attitude control difficulties as they operate ... more Fixed-wing Micro Aerial Vehicles (MAVs) experience attitude control difficulties as they operate in highly turbulent environments. Previous research has identified pressure-based control as a potential approach for augmenting the performance of, or replacing, autopilots reliant on inertial sensors. However, implementation requires an in-depth understanding of the correlation that exists between oncoming gusts and wing-surface pressure variations. This paper investigates the variation of correlation along a representative MAV’s wing-chord and wing-span between upstream flow pitch angle variation and wing-surface pressure variation. Atmospheric turbulence was replicated within the controlled environment of a wind-tunnel using planar grids which generated a turbulence intensity of 12.6%. Despite the unsteady nature of the pressure field, it was discovered that high correlation is evident in the vicinity of the leading edge. Thus a few optimally placed sensors can be used for a pressure...
Bioinspiration & Biomimetics, 2015
This paper explores a method by which an unpowered, fixed-wing micro air vehicle (MAV) may autono... more This paper explores a method by which an unpowered, fixed-wing micro air vehicle (MAV) may autonomously gain height by utilising orographic updrafts in urban environments. These updrafts are created when wind impinges on both man-made and natural obstacles, and are often highly turbulent and very localised. Thus in contrast to most previous autonomous soaring research, which have focused on large thermals and ridges, we use a technique inspired by kestrels known as 'wind-hovering', in order to maintain unpowered flight within small updrafts. A six-degree-of-freedom model of a MAV was developed based on wind-tunnel tests and vortex-lattice calculations, and the model was used to develop and test a simple cascaded control system designed to hold the aircraft on a predefined trajectory within an updraft. The wind fields around two typical updraft locations (a building and a hill) were analysed, and a simplified trajectory calculation method was developed by which trajectories for height gain can be calculated on-board the aircraft based on a priori knowledge of the wind field. The results of simulations are presented, demonstrating the behaviour of the system in both smooth and turbulent flows. Finally, the results from a series of flight tests are presented. Flight tests at the hill were consistently successful, while flights around the building could not be sustained for periods of more than approximately 20 s. The difficulty of operating near a building is attributable to significant levels of low-frequency unsteadiness (gustiness) in the oncoming wind during the flight tests, effectively resulting in a loss of updraft for sustained periods.
Australian Research Centre For Aerospace Automation Faculty of Built Environment and Engineering, Apr 1, 2007
Australian Research Centre For Aerospace Automation Science Engineering Faculty, 2012
Australian Research Centre For Aerospace Automation Science Engineering Faculty School of Engineering Systems, Mar 3, 2012
... Social attitude towards the risks Search and rescue, bushfire fighting vs law enforcement a... more ... Social attitude towards the risks Search and rescue, bushfire fighting vs law enforcement and surveillance Noise ... Free up conventional aircraft for what they are good at: Delivery of aid or personnel, winching, medevac… Ability to provide enhanced service ...
SAE Technical Paper Series, 2015
International Journal of Micro Air Vehicles, 2015
The integration and acceptance of routine Unmanned Aerial Vehicle (UAV) operations within the civ... more The integration and acceptance of routine Unmanned Aerial Vehicle (UAV) operations within the civilian airspace system hinges on the ability of UAV developers, operators and regulators to prove that UAVs, at minimum, have an equivalent level of safety to that of human-piloted aircraft. Regulations, which govern the safe design, manufacture, maintenance and operation of UAV systems, are to be defined so as to ensure this safety objective is met. Therefore, it is important to provide discussion on the definition and application of such safety objectives to ensure appropriate requirements are defined.
The last decade has seen a rapid increase in the development and deployment of Unmanned Airborne ... more The last decade has seen a rapid increase in the development and deployment of Unmanned Airborne Vehicles (UAVs). Previous UAVs have been capable of useful missions with a limited degree of on-board intelligence. However, more on-board intelligence is required to fully exploit the potential of UAVs. The objective of this research is to increase the on-board intelligence in two areas: mission planning; and mission piloting. Thereby improving the integration of a UAV into civilian airspace and reducing operator workload. This paper presents the research towards the development of the Intelligent Mission Planner and Pilot. The IMPP enables a UAV to autonomously plan and to perform missions within civilian airspace. The IMPP employs a novel multidisciplinary approach, exploiting robotics, 3D graphics and computer science techniques. Results are presented based upon testing using real world data from south-east Queensland. These results demonstrate the performance achieved by the mission planning and piloting algorithms.
- Test architecture for prototyping automated dynamic airspace control.
Lessons In History: The Regulation Of "Horse-Less Carriages" And "Pilot-Less Aircr... more Lessons In History: The Regulation Of "Horse-Less Carriages" And "Pilot-Less Aircraft" This oral presentation provides an introduction to current research in the risk management of pilot-less aircraft, or more commonly referred to as Unmanned Aircraft Systems (UASs). A historical review of the risk management of automobiles in the 1800’s is used to establish the motivation behind the research. The review identifies and discusses recurring issues in the regulation of new technologies through the identification of parallels between the regulation of early automobiles and that of the regulation of Unmanned Aircraft Systems (UASs) today. It is found that many of the regulatory challenges facing UASs are analogous to those which faced the automobile industry more than a century and half ago. The historical comparison highlights the potential detriments of policy driven by perception and reinforces the need for informed and objective decision making in the development ...
This webinar was conducted in conjunction with the Australian Road Research Board. The presentati... more This webinar was conducted in conjunction with the Australian Road Research Board. The presentation provides an introduction to unmanned systems and explores some of the opportunities for Australian Road Agencies. Online recording can be found here: http://snack.to/tvul7l0i
This paper discusses a model of the civil aviation reg-ulation framework and shows how the curren... more This paper discusses a model of the civil aviation reg-ulation framework and shows how the current assess-ment of reliability and risk for piloted aircraft has a limited applicability for Unmanned Aircraft Systems (UAS) as technology moves towards higher levels of autonomous decision making. Then, a new frame-work for risk management of robust autonomy is pro-posed, which arises from combining quantified mea-sures of risk with normative decision making. The term Robust Autonomy describes the ability of an au-tonomous system to either continue or abort its oper-ation whilst not breaching a minimum level of accept-able safety in the presence of anomalous conditions. The term combines reliability, safety, and robust-ness. The decision making associated with risk man-agement requires quantifying probabilities associated with the measures of risk and also consequences of outcomes related to the behaviour of autonomy. The probabilities are computed from an assessment under both nominal an...
This keynote presentation provides an introduction to the unmanned aircraft systems (drone) indus... more This keynote presentation provides an introduction to the unmanned aircraft systems (drone) industry in Australia and outlines some of the general challenges facing the sector.
Civil aviation safety regulations and guidance mate-rial classify Unmanned Aircraft Systems (UAS)... more Civil aviation safety regulations and guidance mate-rial classify Unmanned Aircraft Systems (UAS) as ei-ther Remotely-Piloted Aircraft Systems (RPAS) or Autonomous Aircraft Systems (AAS). This distinc-tion is based on the premise that the effective safety risk management of UAS is dependent on the degree of autonomy of the system being operated. However, it is found that there is no consensus on the concept of autonomy, on how it can be measured, or on the na-ture of the relationship between Levels of Autonomy (LoA) and the safety-performance of UAS operations. An objective of this paper is to evaluate existing LoA assessment frameworks for application in avia-tion safety regulations for UAS. The results from a comprehensive review of existing concepts of auton-omy and frameworks for assessing LoA are presented. Six case study UAS were classified using the pub-lished LoA frameworks. The implied LoA of UAS for existing modes of operation (e.g., teleoperation, semi-autonomous) were al...
This paper presents some of the challenges associated with development of an airworthiness regula... more This paper presents some of the challenges associated with development of an airworthiness regulatory framework for Unmanned Aircraft Systems (UAS). The risk paradigm and a simple model describing the regulatory trade-space are developed. The model is used to explain fundamental differences between the regulation of manned and unmanned aircraft. General challenges are presented and the possible regulatory approaches are discussed. Moving forward, it is concluded that the development of an effective airworthiness regulatory framework for UAS should follow a systematic and risk-based process of: 1) specifying safety policy and the safety objectives, 2) developing an airworthiness classification framework, and 3) identifying a regulatory approach suitable to each airworthiness category. These activities should be undertaken before the development of low-level airworthiness standards and procedures.
This conference presentation discusses the development of template safety cases for UAS operation... more This conference presentation discusses the development of template safety cases for UAS operations over populous areas and in non-segregated airspace. Based on the Barrier Bow Tie model, the template provides a simple means for the development and communication of complex safety cases. It focusses discussion on those practical measures that can be put in place to reduce the risks associated with UAS operations. This is ongoing research. The outcome will be a simple tool for use by UAS operators and the regulator.
International Journal of Micro Air Vehicles, 2015
Journal of Aircraft
Fixed-wing Micro Aerial Vehicles (MAVs) experience attitude control difficulties as they operate ... more Fixed-wing Micro Aerial Vehicles (MAVs) experience attitude control difficulties as they operate in highly turbulent environments. Previous research has identified pressure-based control as a potential approach for augmenting the performance of, or replacing, autopilots reliant on inertial sensors. However, implementation requires an in-depth understanding of the correlation that exists between oncoming gusts and wing-surface pressure variations. This paper investigates the variation of correlation along a representative MAV’s wing-chord and wing-span between upstream flow pitch angle variation and wing-surface pressure variation. Atmospheric turbulence was replicated within the controlled environment of a wind-tunnel using planar grids which generated a turbulence intensity of 12.6%. Despite the unsteady nature of the pressure field, it was discovered that high correlation is evident in the vicinity of the leading edge. Thus a few optimally placed sensors can be used for a pressure...
Bioinspiration & Biomimetics, 2015
This paper explores a method by which an unpowered, fixed-wing micro air vehicle (MAV) may autono... more This paper explores a method by which an unpowered, fixed-wing micro air vehicle (MAV) may autonomously gain height by utilising orographic updrafts in urban environments. These updrafts are created when wind impinges on both man-made and natural obstacles, and are often highly turbulent and very localised. Thus in contrast to most previous autonomous soaring research, which have focused on large thermals and ridges, we use a technique inspired by kestrels known as 'wind-hovering', in order to maintain unpowered flight within small updrafts. A six-degree-of-freedom model of a MAV was developed based on wind-tunnel tests and vortex-lattice calculations, and the model was used to develop and test a simple cascaded control system designed to hold the aircraft on a predefined trajectory within an updraft. The wind fields around two typical updraft locations (a building and a hill) were analysed, and a simplified trajectory calculation method was developed by which trajectories for height gain can be calculated on-board the aircraft based on a priori knowledge of the wind field. The results of simulations are presented, demonstrating the behaviour of the system in both smooth and turbulent flows. Finally, the results from a series of flight tests are presented. Flight tests at the hill were consistently successful, while flights around the building could not be sustained for periods of more than approximately 20 s. The difficulty of operating near a building is attributable to significant levels of low-frequency unsteadiness (gustiness) in the oncoming wind during the flight tests, effectively resulting in a loss of updraft for sustained periods.
Australian Research Centre For Aerospace Automation Faculty of Built Environment and Engineering, Apr 1, 2007
Australian Research Centre For Aerospace Automation Science Engineering Faculty, 2012
Australian Research Centre For Aerospace Automation Science Engineering Faculty School of Engineering Systems, Mar 3, 2012
... Social attitude towards the risks Search and rescue, bushfire fighting vs law enforcement a... more ... Social attitude towards the risks Search and rescue, bushfire fighting vs law enforcement and surveillance Noise ... Free up conventional aircraft for what they are good at: Delivery of aid or personnel, winching, medevac… Ability to provide enhanced service ...
SAE Technical Paper Series, 2015
International Journal of Micro Air Vehicles, 2015
The integration and acceptance of routine Unmanned Aerial Vehicle (UAV) operations within the civ... more The integration and acceptance of routine Unmanned Aerial Vehicle (UAV) operations within the civilian airspace system hinges on the ability of UAV developers, operators and regulators to prove that UAVs, at minimum, have an equivalent level of safety to that of human-piloted aircraft. Regulations, which govern the safe design, manufacture, maintenance and operation of UAV systems, are to be defined so as to ensure this safety objective is met. Therefore, it is important to provide discussion on the definition and application of such safety objectives to ensure appropriate requirements are defined.
The last decade has seen a rapid increase in the development and deployment of Unmanned Airborne ... more The last decade has seen a rapid increase in the development and deployment of Unmanned Airborne Vehicles (UAVs). Previous UAVs have been capable of useful missions with a limited degree of on-board intelligence. However, more on-board intelligence is required to fully exploit the potential of UAVs. The objective of this research is to increase the on-board intelligence in two areas: mission planning; and mission piloting. Thereby improving the integration of a UAV into civilian airspace and reducing operator workload. This paper presents the research towards the development of the Intelligent Mission Planner and Pilot. The IMPP enables a UAV to autonomously plan and to perform missions within civilian airspace. The IMPP employs a novel multidisciplinary approach, exploiting robotics, 3D graphics and computer science techniques. Results are presented based upon testing using real world data from south-east Queensland. These results demonstrate the performance achieved by the mission planning and piloting algorithms.
- Test architecture for prototyping automated dynamic airspace control.
Lessons In History: The Regulation Of "Horse-Less Carriages" And "Pilot-Less Aircr... more Lessons In History: The Regulation Of "Horse-Less Carriages" And "Pilot-Less Aircraft" This oral presentation provides an introduction to current research in the risk management of pilot-less aircraft, or more commonly referred to as Unmanned Aircraft Systems (UASs). A historical review of the risk management of automobiles in the 1800’s is used to establish the motivation behind the research. The review identifies and discusses recurring issues in the regulation of new technologies through the identification of parallels between the regulation of early automobiles and that of the regulation of Unmanned Aircraft Systems (UASs) today. It is found that many of the regulatory challenges facing UASs are analogous to those which faced the automobile industry more than a century and half ago. The historical comparison highlights the potential detriments of policy driven by perception and reinforces the need for informed and objective decision making in the development ...
This webinar was conducted in conjunction with the Australian Road Research Board. The presentati... more This webinar was conducted in conjunction with the Australian Road Research Board. The presentation provides an introduction to unmanned systems and explores some of the opportunities for Australian Road Agencies. Online recording can be found here: http://snack.to/tvul7l0i
This paper discusses a model of the civil aviation reg-ulation framework and shows how the curren... more This paper discusses a model of the civil aviation reg-ulation framework and shows how the current assess-ment of reliability and risk for piloted aircraft has a limited applicability for Unmanned Aircraft Systems (UAS) as technology moves towards higher levels of autonomous decision making. Then, a new frame-work for risk management of robust autonomy is pro-posed, which arises from combining quantified mea-sures of risk with normative decision making. The term Robust Autonomy describes the ability of an au-tonomous system to either continue or abort its oper-ation whilst not breaching a minimum level of accept-able safety in the presence of anomalous conditions. The term combines reliability, safety, and robust-ness. The decision making associated with risk man-agement requires quantifying probabilities associated with the measures of risk and also consequences of outcomes related to the behaviour of autonomy. The probabilities are computed from an assessment under both nominal an...
This keynote presentation provides an introduction to the unmanned aircraft systems (drone) indus... more This keynote presentation provides an introduction to the unmanned aircraft systems (drone) industry in Australia and outlines some of the general challenges facing the sector.
Civil aviation safety regulations and guidance mate-rial classify Unmanned Aircraft Systems (UAS)... more Civil aviation safety regulations and guidance mate-rial classify Unmanned Aircraft Systems (UAS) as ei-ther Remotely-Piloted Aircraft Systems (RPAS) or Autonomous Aircraft Systems (AAS). This distinc-tion is based on the premise that the effective safety risk management of UAS is dependent on the degree of autonomy of the system being operated. However, it is found that there is no consensus on the concept of autonomy, on how it can be measured, or on the na-ture of the relationship between Levels of Autonomy (LoA) and the safety-performance of UAS operations. An objective of this paper is to evaluate existing LoA assessment frameworks for application in avia-tion safety regulations for UAS. The results from a comprehensive review of existing concepts of auton-omy and frameworks for assessing LoA are presented. Six case study UAS were classified using the pub-lished LoA frameworks. The implied LoA of UAS for existing modes of operation (e.g., teleoperation, semi-autonomous) were al...
This paper presents some of the challenges associated with development of an airworthiness regula... more This paper presents some of the challenges associated with development of an airworthiness regulatory framework for Unmanned Aircraft Systems (UAS). The risk paradigm and a simple model describing the regulatory trade-space are developed. The model is used to explain fundamental differences between the regulation of manned and unmanned aircraft. General challenges are presented and the possible regulatory approaches are discussed. Moving forward, it is concluded that the development of an effective airworthiness regulatory framework for UAS should follow a systematic and risk-based process of: 1) specifying safety policy and the safety objectives, 2) developing an airworthiness classification framework, and 3) identifying a regulatory approach suitable to each airworthiness category. These activities should be undertaken before the development of low-level airworthiness standards and procedures.
This conference presentation discusses the development of template safety cases for UAS operation... more This conference presentation discusses the development of template safety cases for UAS operations over populous areas and in non-segregated airspace. Based on the Barrier Bow Tie model, the template provides a simple means for the development and communication of complex safety cases. It focusses discussion on those practical measures that can be put in place to reduce the risks associated with UAS operations. This is ongoing research. The outcome will be a simple tool for use by UAS operators and the regulator.