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It is very important to define clear and realistic goals for this projects. I encourage people to leave comments with what they think the goals of this version of Protei should be at the bottom of this page or edit the page itself directly. The potential for this project is clear, and many amazing aspects have been talked about. However, how do we turn the amazing ideas into a reality. The answer is by taking one step at a time. The goal for this version of Protei should be to take a step closer. For that to happen we must create quantifiable and realistic requirements that move the design in the direction of the functional Protei.
This Diagram is not definitive but aims to get us thinking about a sequence of dependent modules that will lead to a successful summer project. I put it up for discussion at the General Meeting on 9th May 2011 - Peter.
The primary reason why I (Cesar) came up with the shape-shifting hull sailing was to collect oil spills. In the process of the development of the technology, building prototypes, many innovations, or at least hypothesis of research accidentally happened. Sey Min and myself called this project "Protei" (the god that can change shape at will). We now think that beyond oil spill, Protei and a shape shifting hull for an unmanned vessel has a lot of potential applications. Protei is now characterised not only by its objective (collecting an oil spill), but also its technology (shape-shifting hull) that is the core of the innovation Protei - as its name says. To sumarize Protei is certainly being developed for oil spill, but we can't limit the scope of the research to oil collection efficiency. What at this stage is the strongest differentiator is the shape-shifting hull for a sailing boat, so the emphasis should be equally split between the
- Innovation in the science of sailing and
- oil collecting technology at sea. One objective is not more important than the other, one serves the other and we are asking the question of how well this technology can address that particular issue.
Performance Target / Operating conditions
Oil response experts (Cedre, DNV,++) use these kind of design values
- wave height: 1.5-2m high in coastal shallow waters, 3-4m high offshore
- towing speed of the boom: between 0.8 and 1 knot to max. boom efficiency
- 2 tonne of oil + sea water emulsion = approx 1 tonne oil recovered
This gives us an idea of the performance we want to achieve:
- Be able to pull a load of at least 2 tonne.
- An extra 500 kg can be added to the load to take into account the added resistance to waves and currents
- Be able to pull the load at 1 knot in any sailing course
- Be able to sail in 1.5-2m waves (off the coast) to 3-4m waves (offhsore)
These performance targets are used in the Main dimension calculation spreadsheet in the VPP page.
Hardware / Mechanical design
First priority: 1. A full scale Remote control Protei.
- This will be known as Protei_06.0_Batman.
- Design and build a full scale version of Protei, an autonomous articulated sail boat.
- Protei 06.0 should be able to tow a long absorbing boom tail.
- Design materials must be low cost, and safe for the ocean environment.
- The specific dimensions of this boom tail should be defined.
- Protei 06.0 should be capable of self-righting.
- Operator should be able to take over control of Protei 06.0 via a remote control.
- This will be used for testing, navigating to safe test areas, and avoiding damage to the Protei or other objects.
- Try to calculate the power consumption to evaluate cruising duration.
A full scale Protei 06.0 should very definitely be the ultimate goal of the summer project. This should include sufficient sensors and control systems for it to be autonomous even if it is not run in that mode but uses a short range remote control method to prove seaworthiness and navigability in a real world situation. Finalised model hull designs should be analysed in a test tank prior to deployment in the ocean. Most important will be to aim for a finished vehicle design that builds on lessons learned and imaginatively solves issues that are still pending. Proving the ability of the vehicle to tow a real oil absorbing boom is a must. It is one of the defining characteristics of the project.
Absorbent boom issues
Once a vehicle has successfully deployed its boom in an oil slick and the boom has become saturated we need to think what happens next. Obviously the first thing would be for the vehicle to navigate back to a home base with its oil laden boom where that boom could be replaced and the vehicle then recommited to the clean-up process. What then of the oil saturated boom it leaves behind? It would seem sensible to clean it in some way and reuse it. It is even possible that the oil recovered from the boom could be reprocessed or re-enter the refinement cycle to ensure it is not wasted.
From a lot of the reading I've done so far it seems a fair amount of the oil collected as the result of an oil spill is burnt off or ends up in a land fill, neither fates contribute to the well-being of the environment.
Choice of materials for the boom, then, become important and one of the selection criteria may well be how easy is it to recover the oil and reuse the material.
I have providing some links on a material called fibretect which is a unwoven cotton based material that incorporates an activated charcoal layer that has the added benefit of trapping lighter fractions and PAH's. The inventor of this product, Dr Seshadri Ramkumar believes this could be used on a boom and, at least in their tank demonstration, it appears to pull oil of a water surface very effectively. Though I do note that the demonstration used refined oil rather than sweet (or sour) crude oil. More importantly Dr Ramkumar also asserts that physical wringing or compression between rollers should separated the oil from the material allowing it to be reused.
Information about his product is given in the following video:
Another material is an Aerogel which is demostrated and described in the following link. Again it should be noted that the demonstration is conducted with refined oil not crude oil.
I have enquiries pending with other boom material manufacturers and await their response which I will update here as they come to hand but I encourage people to add their own information and links in this place, and this can feed into a growing data base of materials whose characteristics are known and for which strategies can be implemented to separate the oil from the absorbent material.
- Peter Keen
<Etienne 20110508: pasted this whole paragraph to the dedicated webpage on Oil Booms >
Second priority : capacity of Protei to sense its environment and set up its own route according to environmental variables. The "AI" on board of Protei.
- Built with all kinds of sensors and microcontrollers,(GPS, Compass, wind speed, motor, accelerometer), set up communication between sensors, actuators and microcontrollers.
- Apply and test some control law in the micro-controller, like autonomous tacking and jibing, way point following, as those discussed today. It would be great if it can work somehow, otherwise find the problems.
- Test how the innovations of Protei, like the articulated hull and front rudder, affect its performance. Formally expressed these features in mathematical models. This might be difficult and three months may not be enough to get it properly. But we can start to think about it.
- Development of an open-source sailing autopilot for autonomous control of Protei 06.0. This autopilot would be capable of the following.
- Generating a route from a supplied list of GPS way-points, using wind speed and direction
- Travel as directly as possible from one GPS way-point to the next
- Adjust for changes to wind direction and speed
- If possible additional features will be added.
- Non-direct route generation to cover as much areas as possible between GPS way-points.
- Obstacle avoidance.
Controlling multiple units with a centralized system
- Oil spill cleaning patterns
- Cruising and "scan" pattern
Controlling multiple unit with a decentralized system
- Oil spill cleaning patterns
- Cruising and "scan" pattern
Web interface to control multiple units
- one user
- multiple users
We have sufficient depth of skills and experience in the team to develop mission control system in parallel with the development of the vehicle hardware. There is some good research being done in this area at the moment in relation to sea-gliders. All these papers are from a recent conference in Gran Canaria (and will no doubt soon be available through the proceedings of the same):
Optimum and adaptive mission planning of gliders
Alberto Alvarez and Baptiste Mourre NATO Undersea Research Center-NURC, Viale San Bartolomeo 400, 19136 La Spezia, Italy
A biologically inspired Neural Controller based on a Self Organization Direction Mapping Network for UVs on Oceanographic Missions.
A. Guerrero-González, et al Universidad Politécnica de Cartagena, Plaza Cronista Valverde s/n, 30202 Cartagena, Spain
An Optimization-Based Path Planner for Underwater Gliders
Josep Isern-González, et al Instituto Universitario SIANI. Universidad de Las Palmas de Gran Canaria, Campus Universitario de Tafira, 35017. Gran Canaria, SPAIN.
Full-scale prototype working prototype (as described above in the "Engineering" paragraph).
As a final test, I suggest the Protei be able to sail autonomously from one location to second. The test area should be free of obstacles and only test the initial autopilot functions. A future test could include obstacles along the path. I don't know geographic area well enough to pick two good locations. My initial thought was to have a 3-4 hour trip with several GPS points along the way. Sail away from the coast at one harbor, then travel down the coast line, and finally reach a second harbor. A team would follow the Protei to monitor.
These are the factors that are affecting Protei performance to capture oil - from the oil perspective (as suggested by Etienne Gernez and Prof Gonzalo Tampier).
List of Symbols
Please consult the dedicated list of symbols to make sure that everyone is talking the same language. The list is under the Math model page for now, but it can be moved.
Read the 100 page handbook that explains Protei_06.0 in detail.
Because this project is so complicated, it will be helpful to split the project into smaller groups focus on specific areas of the project. These smaller groups can each have a group leader, and members can be part of as many groups as they like. This will help similarly interested people meet and work together. This will also help to avoid having huge group conversations that are hard to manage.
- Mechanical Design
- Power System
Mathematical model and simulation Team
- This is the mathematical modeling group of Protei, which will try to grasp the key dynamics of Protei and evaluate its performance.
- Naval Architecture
Control and Communication System
- How we will transmit information to Protei, and how it will use that information.
- This is for the remote control and semi-autonomous control system. The sensors and micro-controller.
- Marketing team : This is for gaining publicity, finding sponsors, and funding of the project.
- Legal aspects:
- breach of collision regulations lookout requirements
- Lloyds Register have rules for clean up vessels(manned)
- contact with the flag state would have to be started and a discussion on how to prevent collisions ( most likely involves installation of hardware [AIS]) needs to be initiated
We have a contact in Lloyds Register, who have an Office in Rotterdam, and they are happy to come and talk to the team, perhaps once we convene in June.