We have identified a cutting-edge method for monitoring pollution in ports as specified in EU Directive 2005/35. This monitoring process is currently costing approximately 350 million Euros per year in the EU. SHOAL will develop a shoal of robotic fish to analyse contaminants in water and produce a real-time map of which pollutants are in the water, in what concentrations and where these are on a 3D map of the port.
SHOAL will use advanced swarm intelligence techniques to control the robots, utilising hybrid particle swarm/ant colony optimisation techniques in order to coordinate the group efficiently and adapt quickly to changes in the environment. This will benefit not only monitoring operations in ports across the EU, but also lead to important advances in robotics, chemical analysis, underwater communications and robot intelligence. At present there are no fully autonomous systems for monitoring pollution in ports. SHOAL is innovative in that it can analyse chemicals not only on the surface of the water (e.g. oil) but also those that are dissolved in the water (e.g. nitrates). This will allow the fish to find pollution from agriculture as well as leaks from vessels in a port.
SHOAL will build robot fish which will function independently and as part of a larger group to analyse and monitor pollution in a port. These robotic fish will be equipped with chemical sensors to find pollutants in the water and modems to create an ad hoc network for communication within the swarm. This will allow the shoal of robot fish to build up a broad map of the pollutants moving through the port in real time whilst adapting naturally to changes in environmental conditions in the port. Beyond this, due to the design of the robots, they will be able to search underwater rather than simply on the surface, meaning that if a leak is still occurring they will be able to isolate it even if it originates underwater (for example from the hull of a ship or an underwater pipeline).
Based on the existing success in designing robotic fish, the team will work on a new generation of fish that can fully operate to monitor pollution in ports as specified in EU Directive 2005/35. More specifically, we will:
- Develop a real-time navigation and control system for a team of 3 robotic fish;
- Deploy a multi-sensor platform in each robotic fish for navigation, communication and pollution monitoring; and
- Create cooperative strategies for the robotic fish team to build a 3D pollutants map.
Policy Context
Two European Directives are concerned with water pollution in ports:
- Ship-source pollution and on the introduction of penalties for infringements (2005/35/EC)
- Water Framework Directive (2000/60/EC)
Description of the way to implement the initiative
The main objective of the SHOAL project is to design and develop three fully functional robotic fish equipped with chemical sensors and a scalable communications infrastructure.
1. The robot fish will detect pollution with on-board electrochemical sensors.
2. By using underwater communications technology, the fish will communicate its findings to the other fish and to the hub located on shore.
3. Swarm intelligence will allow the localisation of the pollution source.
4. Results will be transferred to the Port Authority for action.
One of the project partners in this consortium, the University of Essex, has successfully built the advanced robotic fish which swam autonomously at London Aquarium for nearly two years. The major achievements include novel hybrid control architecture, a 3D fish simulator, fish swimming patterns, simple fish behaviours and layered learning of individual robotic fish. Based on the existing success, the team will work on a new generation of robotic fish that can operate autonomously in a port to search and monitor harmful contaminants, other pollutants and leaks in vessels cooperatively.
Artificial Intelligence and Swarm intelligence
BMT is in charge of creating intelligence for the fish. This will involve both an intelligence for each individual fish and the development of a swarm AI. The fish will have to be able to manage multiple problems; avoiding obstacles, knowing where to monitor pollution, finding the source of a pollution, maintaining communication distance from the other fish, recharging themselves at the charging station and many more. Each individual robotic fish will have an array of sensors and external information that will allow it to navigate the environment
Robotic Design
In nature, fish have astonishing swimming ability after thousands years evolution. The observation of real fish shows that this kind of propulsion is more noiseless, effective, and manoeuvrable than propeller-based propulsion, which has inspired the researchers to build robotic fish that can interact with the aquatic environment efficiently. Instead of the conventional propellers used in ships or underwater vehicles, the undulation movement provides the main energy of robotic fish. The major applications of robotic fish are in the marine & military fields such as detecting leakage of oil pipelines, monitoring water quality monitoring, mine countermeasures, etc.
Chemical Analysis
The established methods for the detection of pollutants in waters are based on sampling and analysis of discrete water samples. The analysis is performed in laboratories located remotely away form the sampling sites and frequently the chemical analysis is carried out with expensive apparatus, such as bench-top spectrometers and chromatographs. The issue with these methods is that, although they function well and provide reliable chemical data, they are laboratory-based, personnel-dependent, time-consuming and expensive. However an emerging research trend in the last 1-2 decades has been the growing interest in research in chemical sensors and biosensors which can meet the monitoring needs of those interest in polluted water analysis.
Communications
Until now underwater communications (UComms) have been mainly focused on point to point links in open sea between an underwater vehicle or seabed sensors and the support ship. Theoretically radio waves are usable in water, however they are of little use for this purpose because of their great attenuation at short distances. Optical solutions such as green-blue laser suffers from scattering and needs a high precision in pointing. The acoustic communication appears as the preferable solution; however the channel is far from ideal, especially in the very shallow water conditions of a port. It has a very limited bandwidth, and causes severe signal dispersion both in time and frequency domain.
The SHOAL project will develop an Underwater Mobile Ad-hoc Network (UMANet) in harsh environmental conditions.
Another important key point is the impact of such communications on the existing environmental constituents and especially real fishes which use the port as their life area. Special care will be taken to protect this unstable balance in selecting appropriate frequency range, reducing acoustic level and minimising data exchange.
Hydrodynamics
The fluid dynamics part of this project will cover two main components: computational fluid dynamics (CFD) and hydrodynamic testing.
Computational Fluid Dynamics: This component will integrate the hydrodynamic and motion control components. The hydrodynamic component will simulate fish movement while motion control will realise fish motion from one location to another. Pollutant spread in the water will also be modelled. The task involves following computational works:
- Modelling pollutant spread due to current effect.
- Modelling pollutant spread due to diffusion
- Modelling pollutant spread due to sea wave
- Modelling pollutant spread due to passing ships
Hydrodynamic Testing: The hydrodynamic testing programme will provide benchmarking data for the CFD study, and will also provide an understanding of the relationship between the manoeuvring behaviour of the fish with the swimming strategy employed (i.e. the amplitudes, frequencies and phases of the motions of the various sections). This will form the basis of a simplified engineering model of the motion control which will be used as a screening tool to identify key cases for more detailed analysis. Through tank (port, harbour) modelling of pollutant spread, results will give clear insight into how pollutant is spreading in the different environment or conditions. Based on these information, the SHOAL system can be designed with more accuracy and efficiency.
Technology solution
Robotic Design
Simulation: The hydrodynamic component will simulate fish movement while motion control will realize fish motion from one location to another. Pollutant spread in the water will also be modelled. The task involves following computational works:
- Modelling pollutant spread due to current effect.
- Modelling pollutant spread due to diffusion
- Modelling pollutant spread due to sea wave
- Modelling pollutant spread due to passing ships
Chemical sensing: Electrochemical Sensors for
- Phenol derivatives;
- Heavy Metals;
- Water Quality (Dissolved O2, Conductivity, ORP).
Instrumentation:
- Hardware compatible and optimised for selected sensor system and detection principle.
- Signal processing and data interpretation algorithms included in user-friendly interface.
Communications
There are two major challenges here:
- Underwater communication
Theoretically, radio waves and optical solutions can be used for communications under waters. The acoustic communication appears as the preferable solution. The SHOAL project will develop an Underwater Mobile Ad-hoc Network in the port environmental conditions which could be seen as one of the most difficult in terms of acoustic propagation.
- 3D localisation of the robotic fish
Acoustic underwater positioning systems already exist as independent functions. Such systems have generally been single role, application specific. The target would be to integrate this function within the communications. The hub will be used as positioning reference for the swarm. In a classical navigation system the mobile has to send recurrent signal to be tracked. Applied to a swarm manoeuvring in a reduced area, this solution will generate a permanent acoustic noise which could affect other systems and disturb the environment. In the frame of this project, the positioning methodology will take advantage of navigation intelligence of the robot.
Advanced intelligence
The fish will have to be able to manage multiple problems:
- Avoiding obstacles,
- Knowing where to monitor pollution,
- Finding the source of a pollution,
- Maintaining communication distance from the other fish,
Each individual robotic fish will have an array of sensors and external information that will allow it to navigate the environment.
Current research into swarm robotics concentrates on emergent behaviour developing from biologically inspired algorithms. These can be based on movement and behaviour of insects, flocks of birds, shoals of fish or other groups. These techniques concentrate on using local information and simple rules to establish a complex group behaviour as a whole in order to achieve predetermined goals. Two examples of swarm intelligence algorithms will be utilized in SHOAL.
Main results, benefits and impacts
Implementation: Field Trials
Field trials will take place in the last year of the project in the Port of Gijón in Spain. The Port Authority of Gijón has been participating in several R&D projects since 1992.
Two locations within the port of Gijón have been suggested to hold the field trials. They have been selected regarding certain parameters (underwater current, vessels movement, access to the sea ... ).
The fields trial will include testing:
- Individual movement of the fish within the port environment
- Underwater communication & localisation system
- Pollution sensor system
- Advanced intelligence and swarm intelligence
Project expected outcomes
3 robot fish will be made. They will integrate the following:
- Electrochemical sensors prototype (Sensors + Hardware + Software)
- Underwater Communications prototype
- Artificial Intelligence prototype
The 3 robot fish will:
- Function independently
- Function as part as a shoal
- Monitor pollution in a port environment
- Communicate the pollution levels and its position
Lessons learnt
This field will be completed by the submitter when the lessons learnt have been identified and understood.
Scope: International