Evaluation of UAVs as an underwater acoustics sensor deployment platform

Marine surveys carried out by Passive Acoustic Monitors conventionally use towed hydrophone arrays, which requires dedicated surface observation boats. This is a costly and slow process, which could be made cheaper and quicker by using Unmanned Aerial Vehicles (UAVs). Presented in this paper are the initial findings from using UAVs to capture underwater acoustic signals from an acoustic test tank

Unmanned Aerial Systems (UAS) for marine mammal detection and underwater noise assessment

Conventional underwater based acoustic deployment platforms, such as boats, drifting systems or moored long term acoustic data loggers are often expensive, complex and are usually deployed in dangerous environments. A novel alternative involving the use of a waterproof Unmanned Aerial System (UAS) for the deployment of underwater acoustic sensors is presented. The system has the capability of overcoming the limitations of current deployment methods, while also being able to self-deploy and self-retrieve, and will improve deployment and redeployment times

Unmanned aerial system for use in environmental monitoring of water body wave motion

This paper details the research conducted on an open source flight controller for the use of monitoring surface and wave motion of water bodies. Testing was preformed on an industrial FANUC robotic arm, where a Pixhawk 2 was tested using pre-preprogrammed circles of varying sizes to mimic the amplitude of sinusoidal waveforms. Results show good to excellent comparability between the circle radii programmed, and the calculated displacement from the Pixhawk's reported acceleration. This was achieved through the use of Fourier Transforms, filtering and integration of the acceleration logged by the Pixhawk during tests. Such a system is envisaged to be used in the reduction of flow noise a hydrophone experiences from surface deployments, where real time monitoring of the surface would raise and lower a deployed hydrophone in the water column to reduce or eliminate flow noise. Further to this, this system could be used for an early warning tsunami detection system, which could compliment systems already deployed, as well as being a cost effective solution for areas where no systems are currently in place

Use of Unmanned Aerial Vehicles (UAV’s) for underwater noise assessment [Poster]

The underwater and airborne acoustic environment forms a critical part of many marine mammals life cycles. Assessment and development of understanding of these acoustic soundscapes is often vital in understanding many marine life and human operation interactions as well as species to species interactions in the natural acoustic environments. Traditional passive acoustic methodologies used for underwater sound and noise measurements include static hydrophones, autonomous loggers, boat-based deployments, towed arrays, drifter systems etc. Most of these systems however also rely on expensive and sometimes hazardous deployments and retrieval methods. The rapid growth in Unmanned Ariel Vehicles (UAV) technologies in recent years has lead to investigation of these platforms to act as enhanced aerial visual platforms for observing marine mammal behaviour, abundance estimation etc. These systems are however often limited by battery life to relatively short in flight deployments. However these platforms can also offer the opportunity for rapid deployment of smart hydrophone systems over a relatively large spatial areas to include acoustic behaviours and sound scape analysis by flying to a site landing on the water and then deploying underwater sensors. Whilst on the waters surface relative power consumption is significantly lower than in-flight allowing significantly longer deployments. Smart systems will then return to some base point with minimal human interaction. A prototype multi-rotor system has been developed and tested in an open water site, capable of flying to site, landing on the water, deploying a wideband hydrophone for underwater noise assessment and then returning to base. Measurements include underwater noise self-noise analysis in-flight, landing, static and take-off and potential implications to marine wildlife. These developments and trials have demonstrated the overall feasibility of wide-scale rapid hydrophone deployment using UAVs for sound field and marine mammal behaviour analysis

Feasibility of a fully autonomous wireless monitoring system for a wind turbine blade

Condition monitoring (CM) of wind turbine blades has significant benefits for wind farm operators and insurers alike. Blades present a particular challenge in terms of operations and maintenance: the wide range of materials used in their construction makes it difficult to predict lifetimes; loading is stochastic and highly variable; and access can be problematic due to the remote locations where turbines are frequently located, particularly for offshore installations. Whilst previous works have indicated that Micro Electromechanical Systems (MEMS) accelerometers are viable devices for measuring the vibrations from which diagnostic information can be derived, thus far there has been no analysis of how such a system would be powered. This paper considers the power requirement of a self-powered blade-tip autonomous system and how those requirements can be met. The radio link budget is derived for the system and the average power requirement assessed. Following this, energy harvesting methods such as photovoltaics, vibration, thermal and radio frequency (RF) are explored. Energy storage techniques and energy regulation for the autonomous system are assessed along with their relative merits. It is concluded that vibration (piezoelectric) energy harvesting combined with lithium-ion batteries are suitable selections for such a system

Feasibility of using unmanned aerial systems for environmental monitoring of the marine environment

This thesis is the culmination of work carried out on a number of different UAS, in order to determine the feasibility of using UAS to deliver sensor payloads to the marine environment. A number of experiments involving said UAS were conducted, and future work detailed. Chapter 2 provides a brief overview of literature in acoustics and UAS, including UAS use around marine mammals. Chapter 3 looks into the noise produced by a gimbal, which relates the noise levels seen to literature and determines if the acoustic signal emitted could interfere with wildlife. Chapter 4 delves into the acoustics generated by the motors and propellers, with a comparison of these results with published literature. Chapter 5 shows the work conducted and implemented on a custom data logging system with in-house designed underwater housing, for use on a Splashdrone UAS, which is used in Chapter 6 for an acoustic survey of the marine environment. Chapter 7 uses on-board accelerometers inside of a flight controller to monitor displacement experienced, for use in monitoring surface heave of a water body. Chapter 8 concludes this thesis with a review on key findings, and a summary of future work that is to be conducted. Overall, this thesis determines that it is feasible to deliver sensor payloads to marine environments to an extent; a number of issues remain, which are detailed throughout this thesis

Using a UAS for environmental monitoring of the marine environment [Abstract]

Using a UAS for environmental monitoring of the marine environment [Abstract

Initial development of an autonomous UAV for underwater data acquisition

The presentation encompassed the current development of a UAV for the deployment of sensors in the marine environment

Integration of low-cost consumer electronics for in-situ condition monitoring of wind turbine blades

Wind turbine blades must be sufficiently durable to withstand fatigue, strong enough to withstand loading but not excessively heavy so as to impose unnecessary loads on the drive train. Thus, different types of materials such as glass reinforced plastic, wood and steel, are used in its construction. The wide-spread of materials used creates great difficulty in predicting the lifetime health of the blades hence the necessity for condition monitoring (CM). CM systems for blades are not yet widely used. Those which are currently deployed are expensive, contributing to rising operating and maintenance costs especially offshore. The current paper describes a vibration-based in-situ CM system, comprised of low-cost consumer electronics (accelerometers, microcontroller and energy harvester), capable of detecting variations in the dynamic properties of turbine blades