PRE2022 3 Group7

Buoy based remote sensing

Group members

Names	Study	ID	Email
Max van Wijk	Electrical Engineering	1736418	m.h.o.v.wijk@student.tue.nl
David van Warmerdam	Electrical Engineering	1714171	d.s.v.warmerdam@student.tue.nl
Luka Tepavčević	Electrical Engineering	1720996	l.tepavcevic@student.tue.nl
Bob Verbeek	Biomedical Engineering	1752510	b.m.verbeek@student.tue.nl
Yu-Hsuan Lin	Computer Science	1672363	y.lin1@student.tue.nl
Saskia ten Dam	Psychology and Technology	1577328	s.e.t.dam@student.tue.nl

Seperate pages of important information

Logbook page: This page contains the logbook, how much time everyone spend per week, and the general planning of group 7.

Interview page: This page contains the interviews that have been conducted by group 7, a summary of each interview, as well as some small descriptions of the interviewees to give some background.

Weekly research and activities : This page contains, for every week, a summary and overview of the deliverables of group 7. The contents of the page have been structured in chronological order. <==== For the tutors, this is where the document that was originally on this page resides now. This has been done for us to start making an overview of how the final wiki page will look.

!!IMPORTANT!!

The order and contents of all of these sections is NOT set in stone, if you feel like a section should go somewhere else, have different content, or be outright removed, please do so (with consent of course).

Introduction

What will be written here:

• A quick summary of coral reefs:
  • What types or coral reefs there are.
  • Why coral reefs are important.
  • What is currently done to protect coral reefs, and what is still missing (state of the art). <= most important part as this is what we're trying to solve

Order of how it could be done.

- Why coral reefs are important. + why do we need to look after them.

Coral Reefs are amongst the most important natural marine structures in the world, affecting both ocean life and land life (especially coastal areas). For ocean life, coral reefs act as a shelter and a breeding ground, being home to thousands of different species of marine life, including fish, crustaceans, corals and larger marine animals ( such as sharks). On the other hand, for on land, coral reefs protect the coastlines from powerful waves and storms. Furthermore, coral reefs bring about many jobs, and therefore many people rely on coral reefs for their lively hoods.

- Types of Coral Reefs

There are three main types of coral reefs currently, fringing reef, barrier reef and an atoll reef. Fringing reefs are the most common and they are found right along the coast line

- What coral reef we will focus on and why

- What is currently being done and what are we trying to do.

Problem Statement

After having done the above mentioned research into coral reefs, their importance, how we can defend them, and how they are currently protected, we have come up with a method of supporting the current researchers by creating a new method of data gathering. We have designed a buoy based sensing system that is comprised of a diver, which is able to move up and down through the water, and a buoy, to where this diver is attached. This buoy would be able to carry any type of sensor that a particular researcher may desire, and measure a particular parameter at a self specified depth. The buoy would be able to send this data back to the researcher in real time, removing the need for any human intervention that could disturb the coral reef, such as human divers or boat engines.

Not only does this new design add to the existing methods of data gathering in coral reefs, solving one problem. But it also makes data gathering less manpower hungry. Because of these reasons, we believe that our design is able to solve the aforementioned problems.

USE Analysis

As the project is focused around the notion of USE (user, society, enterprise), it is of great importance to start by connecting to the future users of our product before finalizing the design. We have done this by interviewing marine biologists and researchers who are closely related to the topic of coral reefs. The interview page shows the questions asked, as well as a quick summary of the interviewee and the interview itself.

Users

As mentioned previously, our main users, and subsequently the first party stakeholders, are researchers focused on coral reefs, marine biologists and scientific divers. They are the foremost people who have the means and desires to stop the deterioration of coral reefs. Therefore, they are the people who will most likely be the ones using our design. Other stakeholders of our design include funders of our design, second party climate researchers, people living close to coral seasides and, in some sense, the government. None of these people will ever use our design. However, they will all benefit from our design being implemented. Funders, and subsequently the government (if they also fund the project), will make a profit of off the deployment of our design. Other climate researchers will benefit from the increase in accurate data. Finally, inhabitants of the seaside coral reefs will be able to keep their businesses alive, be they fishing or tourism.

Society

Enterprise

Research

I think here we could have :

- Types of potential sensors that need to be used

- Moscow Table

- Solution Encyclopedia

- Potentially what external forces act on the buoy (i.e. wind and tides)

The design of the buoy

Design Process

Describe how, for each part of the design, how the designs changed over time, and why these changes where made.

The main focus of the design process was to design a diver that would be attached to a buoy which would be lowered through the water whilst carrying sensors to be able to monitor the water quality at different depths.

Anchor

describe the transition from anchor to reef hook to multiple reef hooks.

The original ideas for the buoy and diver included an anchor as it was found that anchors were the most suitable for deploying the buoys in the coral reefs such that they would not be swept away by tides and wind. Furthermore it was considered to be the easiest and most efficient way to deploy a buoy. But whilst doing further research and consulting with interviewees that could have been possible users, it was found out that for coral reefs, anchors were not as viable of an option due to how destructive the process on anchoring would be. Furthermore in many reefs anchors are also banned. Therefore with this new found knowledge, the original designs were further developed to be suited to being deployed in coral reefs. Alternatives were found to replace the anchor, with the most promising alternative being mentioned by one of the potential users, which was the use of a reef hook. The only issue for the designs was that one reef hook would not be sufficient to properly anchor the buoy as such multiple reef hooks were included in the designs.

Cables

from chains to cable.

Winch

State why this has basically not changed throughout the whole project + maybe say why only 1 winch was chosen.

Diver

Shape of the diver and what materials where initially planned, but where later changed to X.

Base

Shape, dimensions and weight changes that may have happened.

Initial Designs

Idea 1

Concept:

This initial concept shows a buoy that is connected to an anchor by chain. Most of the electronic equipment which does not include the different sensing equipment would be within the main frame of the buoy above the water. Whereas the sensors would be situated within the diver which would be lowered into the water to take measurements at different depths. The diver would be separate from the buoy but it would be connected to a winch within the buoy so that the depth of the diver can be changed accordingly. The diver is linked to the anchoring line by means of a shackle type object. This would prevent the diver from being swept away by currents.

Flaws:

- Uses an Anchor, in many Coral Reefs, anchors are banned because they would destroy large amounts of coral that would take many years to regrow.

- Chains have to be longer than the average depth where the buoy is situated due to the tides. This could mean that the chains could potentially also destroy the corals around the anchor.

- Shackles could potentially get stuck between the chain links if the chains are too large.

Main Body of Design

Diver Concept

Idea 2

Concept:

The second concept uses the idea that the diver is able to control its own depth by using a motor that is fixed inside of the diver. This would mean that there would be less stress on the wires (attached to the winch) that connect the diver to the buoy as the wires would not have to be able to withstand the weight of the diver by itself. The chains connecting the the anchor are replaced with a cable/ line such that the wheels used to move the diver would always stay in contact with the cable at all times. Furthermore the cable would go through a hollowed out gap, as seen in the second image below, to prevent an asymmetrical distribution of weight as much as possible to prevent the diver from detaching from the the cable and being swept away.

Flaws:

- Uses an Anchor, in many Coral Reefs, anchors are banned because they would destroy large amounts of coral that would take many years to regrow.

- Motor inside of the takes up extra space which could have been used for different sensors.

Main body of idea 2

Developed Designs

Developed Idea 1

Concept:

This Developed Design uses Reef hooks as compared to the initial anchor. Therefore it would be attached to ledges rather than being deployed down which would minimise the damage done to surrounding corals. The Design would use three separate reef hooks attached in a wide area at approximately 120 degrees from one another such that the buoy would stay in an approximately central location with reference to the locations where the reef hooks are attached. Furthermore the diver would be connected to all 3 lines to act as guides so that the diver is unable to be swept away as it is lowered into the water.

The second image shows potential ideas for reef hook designs that could be used be used. This was investigated as conventional Reef Hooks were design for divers to hook on briefly so that they would not get swept away. As such the design had to be adjusted to be able to last longer underwater holding the buoy in place.

Flaws:

- Reef hooks are located further away from one another. Therefore a lot of space would be taken up underwater by the buoy, this might make it more difficult for larger marine animals to swim in the general location of the buoy without potentially dislodging one of the reef hooks by accidentally crashing into one of the lines.

- The 3 extra cables that connect the diver to the lines (preventing diver from being swept away) would have to be very long for the area near the bottom. This would mean that the diver would either have to be able to retract the cables into it, taking up valuable space that could have been used for carrying sensors. Or the cables would have to be left to stay out all the time, which would bring about the problem that the cables would be left to float all the time unless the diver is at its maximum depth. This could mean that the cables could degrade quicker.

- The Reef Hooks would need to be setup manually by divers. This would bring about the problem of how getting suitable divers to get to the depths required along with the safety of the divers and the time it takes for the setup.

Developed Idea 2

Concept:

This concept removes the need for anchoring and instead has the buoy automatically move to the desired destination through the use of GPS from satellites. The reason it is thought to be feasible is because coral reefs act as natural wave barriers due to the fact that they are able to diminish the power of waves coming from the ocean by approximately 86 - 97%. For this design the diver is not guided by any line connected to an anchor or reef hook. Instead it is will be left to sink due to its weight, but the winch will control the depth at which the diver is allowed to ago, along with pulling it back up towards the surface.

Flaws:

- Much higher power consumption. A buoy with this design would have to consume a lot more power as it would have to automatically self correct its position using propellers so that it can stay the correct relative location that the user would want to measure, without being slowly swept away. As such this might impact the overall performance of the sensing equipment and the buoy overall.

- In the case of tropical storms, there is a chance for the buoy to be tipped over/ upside down as it is not connected to anything underwater. Even weaker tropical storms or just stronger winds might be able to tip the buoy over.

Developed Idea 3

Concept:

The concept for this design is a mix between using an anchor and reef hooks. It uses a large object, such as a boulder, underwater as a 'natural' anchor to which 4 reef hooks are attached to it. This way it does not introduce a very heavy load that could destroy the corals underneath it. Otherwise the idea has similar elements to the first initial design when it comes to the diver.

Flaws:

- Reef Hooks would have to be manually secured by divers, therefore it would be important to pay attention how deep the location is because certain depths require more experienced divers.

- The location where the buoy would have to be surveyed first to check if a 'large object such as a boulder is within the vicinity to act as the 'natural' anchor.

Final Design Choice

Show the final design of the buoy and state what could be further improved on the design.

Mechanics of the Diver Movement

Describe in detail (more detailed than we have done in the design choices) how to diver will actually be able to move up and down through the water. Furthermore, talk about the limitations that the diver will have due to the chosen design (these limitations could also be a separate section for talking about the overall limitations).

Simulations

CAD stress test

Show CAD simulations, state why they are important to the design, and explain all images correctly.

Unity physics simulation

Talk about the physics simulation (showing may be difficult), explain the limitations set on the simulation, and describe what we wanted to get out of this simulation.

References