Persistent Autonomy means going beyond what has been done before. PANDORA is creating a new class of AUVs that keep going under extreme uncertainty. AUVs that respond to system faults by doing what they can. AUVs that generate their own missions when idle. AUVs that act appropriately under unexpected environmental challenges.
Humankind needs a new class of underwater vehicle to address the new challenges that deep sea exploration and mechanization create. A PANDORA AUV constantly replans, continuously questions its assumptions, and adjusts its skills to fit its immediate environment.
Leading academics are collaborating to integrate the very best in underwater vehicle design, real time planning, robust control, mapping and online skill adaptation.
Five Universities are coordinating as part of the EU FP7 program, with industrial oversight provided by BP, SubSea7 and SeaByte. Pandora will be innovating by using an agile distributed integration model. Systems will incrementally developed, tested and deployed across Europe continuously.
Pandora is a three year project with major technology demonstrations scheduled. The three tasks are:
1. Hull inspection
2. Anchor chain cleaning
3. Valve operation
These demonstrations will occur at facilities in Scotland or Spain. A critical performance metric is the infrequency of engineer intervention. These difficult tasks are currently carried out by skilled ROV operators at great expense, and are not always successful.
On April 2015 the HWU team visited The Underwater Centre site in Fort William (UK) to conduct the final trials with Nessie AUV. The task is the Autonomous Inspection of a human-made structure and in this case the Fort William site represent a perfect place to test our effort in real sea conditions.
Nessie AUV has visited the site during early trials showing its capabilities over a different set of tasks, among which data gathering and long-term navigation. The experience collected during previous trials allowed the HWU team to identify a suitable mission area, monitoring also the effect of tidal currents that can affect the performances of the AUV while operating in shallow waters.
After some initial preparation runs, the vehicle has been tasked to carefully inspect a portion of the marine pier in complete autonomy, leaving to the team monitoring the evolution of the missions through the use of the operator interfaces developed during the project.
In this scenario the HWU team is able to test the final integration of all the main components of the PANDORA’s software architecture. Contributions from our partners KCL (plannning) and NTUA (robust control), as well as the agile integration process, allowed a successful trial campaign, resulting in 5 days of operations, several gigabytes of collected data and a high number of successful inspections in the real sea environment.
Download the flyer: AURO CFP – Marine Robotoics
~Special Issue Call for Papers~
“Towards Long-Term Autonomy in Marine Robotics”
Marc Carreras, University of Girona, Spain
David Lane, Heriot-Watt University, United Kingdom
Francesco Maurelli, Heriot-Watt University, United Kingdom
Kanna Rajan, University of Porto, Portugal
In recent years, persistent autonomous operations have become a key area of interest for marine robotics researchers. As hardware costs have plummeted, sensors measuring various oceanographic properties have proliferated and the use of robotic platforms within the ocean science community has increased, the need for increased autonomy to perform tasks over large spatial and temporal durations. The challenge in doing so, is particularly severe in the context of the marine environment however, and especially for robotic assets to be observable and communicable over space and time. Over and beyond making time-series measurements marine robots have demonstrated their capability to respond to episodic events, perform targeted sample collection, track dynamic phenomenon in rough coastal environments and make quasi-synoptic observations in the meso-scale.
However, there continue to be significant challenges to marine robotic operations. While commercial deep-water oilfield inspection with autonomous vehicles is now a commercial reality, fielded robots continue to rely heavily on accurate a priori models of the subsea assets and expose limited capabilities for autonomous decision making.
Most autonomous vehicles in the marine environment are limited to preplanned missions, or to limited forms of autonomy involving script switching and re-parametrisation in response to pre-programmed events. Realizing the persistent autonomy that users in the ocean increasingly demand is involving a greater capability in understanding sensed events to detect failure and error, and more capable task planning approaches that can adapt behaviour and control in novel ways.
Topics of interest include, but are not limited to:
Autonomous long-term navigation, localization and SLAM
Automated dynamic re-planning, planning under uncertainty
Semantic-based world modelling, probabilistic approaches in ontologies
Architectures for long-term autonomy
Robust learning techniques
Probabilistic graphical models
Bio-inspired and bio-mimetic approaches
Multi-vehicle cooperation potentially in multiple domains (air, surface, underwater)
In this special issue of Autonomous Robots journal, we invite:
– Research papers to report innovative work in the field (up to 20 pages)
– Applied research case-studies to analyse industrial needs, current states and needs for current and future operations (up to 20 pages)
Paper submission deadline: 15th October 2014
First reviews completed: 15th January 2015
Revised papers due: 15th February 2015
Potential publication date: Summer 2015
Manuscripts must be submitted to: http://AURO.edmgr.com. Choose “Long-term autonomy in Marine Robotics” as the article type.
On the 5th of May, KCL visited NTUA to work on path planning, and to make some initial steps in energy estimation.
The first goal of the week was to generate a fast motion for the AUV (Nessie) and to explore the different types of motion capable by NTUA’s controllers. In response to the former objective, the team at NTUA developed a new controller for trajectory-tracking, to complement the existing waypoint-tracking controller. The new controller avoids lateral motions, and relies on surge. This makes it more energy efficient.
Using both controllers, the planner is able to combine the fast and controlled motions to achieve more complex, but reliable behaviour, such as slowing down to move through tight spaces or performing fly-by inspections. Most importantly, the AUV will move faster.
The integration on energy estimation, while still preliminary, is promising. The estimated thrust required for a trajectory was made available through a ROS service, estimated using the dynamics of the vehicle and the relevent motion control.
Next steps in this direction involve HWU: converting the thrust into energy estimations for KCL. Accessable from the knowledge-base and ontology, this information will be used to replan when energy costs for the current action grow too high, or to perform opportunistic planning when a task comes in under budget.
Researchers from HWU visited KCL on the 12th of March to continue integration of the planning and ontology nodes of the PANDORA architecture. The work produced a new node which collates and distributes information. By implanting an ontology in the new node, HWU are able to reason about the collected information and provide the planner with dynamic updates that affect the plan that is currently executing.
In order to test this link, a new scenario has been devised: the AUV will be placed in a completely unknown environment, and be asked to count the pillars. In reality the tank contains one pillar and one buoy. Pillars are recognised from sensor data, but only after inspection from multiple angles.
Using the integration between the ontology and the planner, new goals and inspection areas can be dynamically created and passed to the planner, as well as new knowledge about obstacles that invalidate the current plan. The planner will replan, when required, avoiding detected obstacles and carefully inspecting the objects.
The scenario will be run first in simulation, and then in the wave tank at HWU.
Researchers from KCL visited UdG between the 17th and 24th of January, successfully completing work on integrating the controllers of the valve turning scenario into the planning architecture. This involved running the scenario many times during the week, with the Girona 500 AUV.
The scenario begins with a panel, hidden somewhere in the sparsely decorated pool. The AUV is given a set of coordinates at which the panel might be. The planner directs the AUV to search for the panel, move close to inspect the valves, detect their orientation, and finally to turn the valves to the correct configuration.
The architecture was modeled to be robust — replanning when new information is discovered, or the environment does not meet expectations. This means that when the valves do not turn as expected, the Girona 500 AUV would try again and again, grasping persistently with its end effector.
During the week, the two teams met to decide how their collaboration should continue. The next steps will integrate planning with the chain cleaning scenario; further improve the valve turning scenario; and combine both to form a longer, more elaborate mission.
From the 28th of November to the 5th of December, researchers from Istituto Italiano di Tecnologia (IIT) came to the University of Girona (UdG) to do different tests to develop a successful valve turning.
During this short period of time the two teams have worked together in two different tasks: First, the integration and testing of the new end-effector. Second, testing the Reactive Fuzzy Decision Maker (RFDM) to evaluate the safety of the valve turning.
The new end-effector has been designed in three different parts: First the shape of the passive gripper to grasp the valve handle, second a camera installed inside the center of the end-effector to see the manipulated elementa and third a Force/Torque sensor to evaluate the quality of the grasping and the torque needed to turn the valve.
An external thruster has been install in the valve turning scenario in order to add perturbations during the manipulation task. The perturbations effect the valve turning and thus allow to detect the parameters to evaluate the safety. Furthermore, the communication between the RFDM and the Learning by Demonstration reproductor has been tested.
During the last week of November NTUA and UdG members put their efforts together to push forward the autonomous chain cleaning task of the PANDORA Project. To this end it is required to detect the chain links and follow them accurately.
UdG team provided a module that performs detections of chain links on the sonar imagery. The chain link detector has been designed to overcome the difficulties of performing object recognition on sonar data (such as the presence of noise, moving shadows or intensity alterations due to viewpoint changes). Taking as input the link detections, NTUA team developed a module that fits a curve through the multiple detections and groups them to obtain a waypoint at the center of each link. The last step that must be performed consists in concurrently follow the identified waypoints while performing new detections. Here, two problems were identified. First, the insonification area of the forward-looking sonar lies always several meters ahead of the vehicle, so the AUV must point on the direction of the last link while keeping its position over the current one. Second, if this two movements are not well coordinated the chain can easily drop off the sonar’s field of view since it is very narrow (30º).
These algorithms were tested in the UdG water tank using Girona 500 AUV equipped with the ARIS3000 sonar, over a mock up of a chain of 7 meters. Successful results were obtained in the link detection and path generation stages. For the following algorithm new strategies are under development.
Great success of the Pandora project in San Diego, California, USA for the Oceans’13 conference, 23-26 September 2013, the biggest conference in oceanic engineering.
The conference was very well attended with two exhibition halls, and several parallel technical tracks, and in-water demos at the harbour, being a unique possibility to showcase the Pandora project and its results.
Alongside the hard work, some time for an Hawaiian-style dinner at USS Midway was well deserved for the Pandora team:
From the 14th to the 21st of June, researchers from NTUA came to the University of Girona to do some tests with the Girona500 equipped with the manipulator.
Arnau Carrera (UdG), Narcís Palomeras (UdG), George Karras (NTUA) and Charalampos (Babis) Bechlioulis (NTUA) during the experiments in the UdG water tank
During this period of time, the NTUA and UdG teams worked together and redesigned the control of the manipulator, obtaining a new, more precise and smooth controller. Additionally, the water jet was installed on top of the manipulator, and the control algorithm to keep the robot stable in front of the panel was improved, so as to be used while the water jet is working and being moved using the arm.
From the 3rd to the 7th of June, members of the team at IIT came to the University of Girona to do some tests with the Girona500 equipped with a manipulator.
Arnau Carrera (UdG), Matte Leonetti (IIT) and Nawid Jamali (IIT) during the experiments in the UdG water tank
In this short space of time, the two teams worked on integrating a haptic device to teleoperate the Girona500 AUV and the manipulator. Once the integration was completed, several trials were performed to demonstrate the task. These experiments have highlighted some weak points in the first theoretical approach and provides the opportunity to improve on this work.
There was also discussion relating to the integration of the force torque sensor, and a decision was made to add a camera to the hand on the manipulator. Furthermore, some experiments involving thruster failures in the Girona500 AUV were performed.