Design and Control of a Flight-Style AUV with Hovering Capability

The small flight-style Delphin AUV is designed to evaluate the performance of a long range survey AUV with the additional capability to hover and manoeuvre at slow speed. Delphin’s hull form is based on a scaled version of Autosub6000, and in addition to the main thruster and control surfaces at the rear of the vehicle, Delphin is equipped with four rim driven tunnel thrusters. In order to reduce the development cycle time, Delphin was designed to use commercial-off-the-shelf (COTS) sensors and thrusters interfaced to a standard PC motherboard running the control software within the MS Windows environment. To further simplify the development, the autonomy system uses the State-Flow Toolbox within the Matlab/Simulink environment. While the autonomy software is running, image processing routines are used for obstacle avoidance and target tracking, within the commercial Scorpion Vision software. This runs as a parallel thread and passes results to Matlab via the TCP/IP communication protocol. The COTS based development approach has proved effective. However, a powerful PC is required to effectively run Matlab and Simulink, and, due to the nature of the Windows environment, it is impossible to run the control in hard real-time. The autonomy system will be recoded to run under the Matlab Windows Real-Time Windows Target in the near future. Experimental results are used to demonstrating the performance and current capabilities of the vehicle are presented

Review of lessons learned after five years of shallow water autonomous underwater vehicles (AUV) operations

The Unidad de Tecnología Marina (UTM) acquired in 2010, due to the wide scientific requirement to obtain high quality images of the seafloor, a couple of AUV´s for shallow waters applications with the aim to support marine research operations in coastal waters. The vehicles has been used as a routine science vehicle but also for technical development. During these years a valuable experience has been gained for future operation on either, coastal and open waters with new and more performant platforms.Peer Reviewe

Low cost underwater acoustic localization

Over the course of the last decade, the cost of marine robotic platforms has significantly decreased. In part this has lowered the barriers to entry of exploring and monitoring larger areas of the earth's oceans. However, these advances have been mostly focused on autonomous surface vehicles (ASVs) or shallow water autonomous underwater vehicles (AUVs). One of the main drivers for high cost in the deep water domain is the challenge of localizing such vehicles using acoustics. A low cost one-way travel time underwater ranging system is proposed to assist in localizing deep water submersibles. The system consists of location aware anchor buoys at the surface and underwater nodes. This paper presents a comparison of methods together with details on the physical implementation to allow its integration into a deep sea micro AUV currently in development. Additional simulation results show error reductions by a factor of three.Comment: 73rd Meeting of the Acoustical Society of Americ

An Optimized, Data Distribution Service-Based Solution for Reliable Data Exchange Among Autonomous Underwater Vehicles

Major challenges are presented when managing a large number of heterogeneous vehicles that have to communicate underwater in order to complete a global mission in a cooperative manner. In this kind of application domain, sending data through the environment presents issues that surpass the ones found in other overwater, distributed, cyber-physical systems (i.e., low bandwidth, unreliable transport medium, data representation and hardware high heterogeneity). This manuscript presents a Publish/Subscribe-based semantic middleware solution for unreliable scenarios and vehicle interoperability across cooperative and heterogeneous autonomous vehicles. The middleware relies on different iterations of the Data Distribution Service (DDS) software standard and their combined work between autonomous maritime vehicles and a control entity. It also uses several components with different functionalities deemed as mandatory for a semantic middleware architecture oriented to maritime operations (device and service registration, context awareness, access to the application layer) where other technologies are also interweaved with middleware (wireless communications, acoustic networks). Implementation details and test results, both in a laboratory and a deployment scenario, have been provided as a way to assess the quality of the system and its satisfactory performanceEuropean Commission H2020. SWARMs European project (Smart and Networking Underwater Robots in Cooperation Meshes), under Grant Agreement No. 662107-SWARMs-ECSEL-2014-1, partially supported by the ECSEL JU, the Spanish Ministry of Economy and Competitiveness (Ref: PCIN-2014-022-C02-02)

ROAZ Autonomous Surface Vehicle Design and Implementation

The design of an Autonomous Surface Vehicle for operation in river and estuarine scenarios is presented. Multiple operations with autonomous underwater vehicles and support to AUV missions are one of the main design goals in the ROAZ system. The mechanical design issues are discussed. Hardware, software and implementation status are described along with the control and navigation system architecture. Some preliminary test results concerning a custom developed thruster are presented along with hydrodynamic drag calculations by the use of computer fluid dynamic methods

Design considerations for engineering autonomous underwater vehicles

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2007Autonomous Underwater Vehicles (AUVs) have been established as a viable tool for Oceanographic Sciences. Being untethered and independent, AUVs fill the gap in Ocean Exploration left by the existing manned submersible and remotely operated vehicles (ROV) technology. AUVs are attractive as cheaper and efficient alternatives to the older technologies and are breaking new ground in many applications. Designing an autonomous vehicle to work in the harsh environment of the deep ocean comes with its set of challenges. This paper discusses how the current engineering technologies can be adapted to the design of AUVs. Recently, as the AUV technology has matured, we see AUVs being used in a variety of applications ranging from sub-surface sensing to sea-floor mapping. The design of the AUV, with its tight constraints, is very sensitive to the target application. Keeping this in mind, the goal of this thesis is to understand how some of the major issues affect the design of the AUV. This paper also addresses the mechanical and materials issues, power system design, computer architecture, navigation and communication systems, sensor considerations and long term docking aspects that affect AUV design. With time, as the engineering sciences progress, the AUV design will have to change in order to optimize its performance. Thus, the fundamental issues discussed in this paper can assist in meeting the challenge of maintaining AUV design on par with modern technology.This work was funded by the NSF Center for Subsurface Sensing and Imaging Systems (CenSSIS) Engineering Research Center (ENC) grant no. EEC-99868321

The augmented reality framework : an approach to the rapid creation of mixed reality environments and testing scenarios

Debugging errors during real-world testing of remote platforms can be time consuming and expensive when the remote environment is inaccessible and hazardous such as deep-sea. Pre-real world testing facilities, such as Hardware-In-the-Loop (HIL), are often not available due to the time and expense necessary to create them. Testing facilities tend to be monolithic in structure and thus inflexible making complete redesign necessary for slightly different uses. Redesign is simpler in the short term than creating the required architecture for a generic facility. This leads to expensive facilities, due to reinvention of the wheel, or worse, no testing facilities. Without adequate pre-real world testing, integration errors can go undetected until real world testing where they are more costly to diagnose and rectify, e.g. especially when developing Unmanned Underwater Vehicles (UUVs). This thesis introduces a novel framework, the Augmented Reality Framework (ARF), for rapid construction of virtual environments for Augmented Reality tasks such as Pure Simulation, HIL, Hybrid Simulation and real world testing. ARF’s architecture is based on JavaBeans and is therefore inherently generic, flexible and extendable. The aim is to increase the performance of constructing, reconfiguring and extending virtual environments, and consequently enable more mature and stable systems to be developed in less time due to previously undetectable faults being diagnosed earlier in the pre-real-world testing phase. This is only achievable if test harnesses can be created quickly and easily, which in turn allows the developer to visualise more system feedback making faults easier to spot. Early fault detection and less wasted real world testing leads to a more mature, stable and less expensive system. ARF provides guidance on how to connect and configure user made components, allowing for rapid prototyping and complex virtual environments to be created quickly and easily. In essence, ARF tries to provide intuitive construction guidance which is similar in nature to LEGOR pieces which can be so easily connected to form useful configurations. ARF is demonstrated through case studies which show the flexibility and applicability of ARF to testing techniques such as HIL for UUVs. In addition, an informal study was carried out to asses the performance increases attributable to ARF’s core concepts. In comparison to classical programming methods ARF’s average performance increase was close to 200%. The study showed that ARF was incredibly intuitive since the test subjects were novices in ARF but experts in programming. ARF provides key contributions in the field of HIL testing of remote systems by providing more accessible facilities that allow new or modified testing scenarios to be created where it might not have been feasible to do so before. In turn this leads to early detection of faults which in some cases would not have ever been detected before

Design and evaluation of an integrated GPS/INS system for shallow-water AUV Navigation

The major problem addressed by this research is the large and/or expensive equipment required by a conventional navigation system to accurately determine the position of an Autonomous Underwater Vehicle (AUV) during all phases of an underwater search or mapping mission. The approach taken was to prototype an integrated navigation system which combines Global Positioning System (OPS) and Inertial Measurement Unit (IMU), waterspeed and heading information using Kalman filtering techniques. Actual implementation was preceded by a computer simulation to test where the unit would fit into a larger hardware and software hierarchy of an AUV. The system was then evaluated in experiments which began with land based cart tests and progressed to open water trials where the unit was placed in a towed body behind a boat and alternately submerged and surfaced to provide periodic OPS updates to the Inertial Navigation System (INS). Test results and qualitative error estimates indicate that submerged navigation accuracy comparable to that of differential OPS may be attainable for periods of 30 seconds or more with low cost components of a small physical size.http://archive.org/details/designndevaluati1094535102NANAU.S. Navy (U.S.N.) authors