Arduino Autonomous Filtering Vessel

In this Instructable I am going to be showing you how I designed and made my proposed solution for the current Red Algae problem in the Gulf Coast waters. For this project I wanted to design a fully autonomous and solar powered craft that could navigate the waterways, and using an onboard natural filtration system, could filter out the excess nutrients and toxins from the Dinoflagellates and Karena Brevis algae. This design was created to show how technology can be used to help fix some of our current environmental issues. Unfortunately it did not win any awards or place in my local small town science fair, but I still enjoyed the learning experience and hopefully someone else can learn something from my project.

Of course any time you are going to be solving a problem you need to do some research. I had heard about this problem through a news article online and that got me interested in designing a solution for that environmental problem. I started by researching what exactly the problem was, and what was causing it. Here is a section of my research paper showing what I found during my research.

"The Red Tide is a growing annual problem for the waters of Florida. Red Tide is a common term used for a large, concentrated group of algae that sporadically grows due to the increase in available nutrients. Currently, Florida has been facing a rapid increase in the size of the Red Tide, which is causing a growing concern for the safety of the aquatic wildlife in the area, as well as any individuals who could come in contact with it. The Red Tide is most commonly made up of a species of algae known as a Dinoflagellate. Dinoflagellates are unicellular protists that produce toxins like brevetoxins and ichthyotoxin, which are highly toxic to marine and land life that come in contact with them. Dinoflagellates reproduce asexually through mitosis, the splitting of a cell producing an exact copy. Dinoflagellates feed on other protists in the water like Chysophyta’s, the most common form of non toxic algae. Dinoflagellates also reproduce asexually causing their numbers to grow rapidly when new nutrients are introduced.

The main cause of their rapid increase in food is due to the introduction of large quantities of nutrients that are washed from farms during rainstorms and carried into the ocean shores from nearby rivers and streams. Due to the high reliance in man-made fertilizers for agriculture, the amount of available nutrients in surrounding farmlands is higher than it has ever been. Whenever there is a rainstorm in most parts of the eastern country, that rain washes a lot of those fertilizers out of the top soil and into the surrounding creeks and streams. Those streams eventually collect into rivers combining all of their collected nutrients into one large group that gets dumped into the Gulf of Mexico. This large collection of nutrients is not a natural occurrence for the marine lifes present, which is why it results in an uncontrollable growth of algae. As the Dinoflagellates’ main source of food, the rapid increase in algae provides a large source of food for a fast growing life form.

These large groups of Dinoflagellates produce toxic chemicals known to kill most aquatic life that come in contact with them. According to WUSF, a local Florida news station, in the bloom of 2018 there were 177 confirmed manatee deaths from the Red Tide as well as another 122 deaths that were suspected to be related. Of the 6,500 expected manatees in the Florida and Puerto Rico waters, this is a huge impact on the survival of this species, and that is just the impact on one species. Red Tide has also been known to cause respiratory problems for those who have been in close proximity to any of the blooms. Since Red Tide grows in the canals throughout some beach towns, this is an obvious safety hazard for anyone living in those communities. The toxin Dinophysis, produced by the Red Tides, has also been known to commonly infect the local shellfish populations resulting in diarrhetic shellfish poisoning, or DSP, in those who have eaten infected shellfish. Thankfully, it is not known to be fatal, but it can result in digestive problems for the victim. However, another toxin produced by some Red Tides, Gonyaulax or Alexandrium, can also infect shellfish in waters contaminated with the tides. Eating shellfish contaminated with these toxins causes paralytic shellfish poisoning, or PSP which in the worst cases has resulted in respiratory failure and death within 12 hours of ingestion."

Quote from my research paper

"My proposed solution is to build a fully autonomous solar-powered marine vessel that features a micro particle natural filtration system onboard. The entire system will be powered by onboard solar panels and propelled by two brushless, ducted motors in a thrust vectoring setup. The filtration system will be used to filter excess nutrients and dinoflagellates as it navigates the waterways autonomously. The vessel will also be used as a shuttle system for the local community. I started by first researching the problem and how this problem had started. I learned that the surges of Red Tide were caused by the large quantities of nutrients, like nitrogen, in the local waters. Once I discovered what was causing the problem I was able to start brainstorming a solution that could help diminish the size of the annual Red Tides.

My idea was a vessel similar in size and shape to a pontoon boat. This vessel would have a skimmer between the two pontoons that would lead oncoming water through a mesh filter to remove large particles, and then through a permeable membrane filter that would remove the nitrogen micro particles present. The filtered water would then flow out the back of the boat through the opposite skimmer. I also wanted this vessel to be fully electric, so it would be quiet as well as being safer, with less of a chance of leaking any toxic liquids into the surrounding waters. There would be several solar panels on the vessel as well as a charge controller with a lithium ion pack to store any excess power for later use. My last goal was to design the vessel in a way that it could be used for public transport for the local community. With all of these design choices in mind, I started sketching out several ideas on paper to try and work through any potential problems."

Once I had my research out of the way I had a much better idea of the problem and what was causing it. I then moved to brainstorming and designing. I spent several days thinking of lots of different ways to solve this problem. Once I had some decent ideas I moved to sketching them out on paper to try and work out some design flaws before moving to CAD. After another couple days of sketching I created a list of parts I wanted to use for the design. I used all of my prize earnings from the previous years science fair plus a little more to purchase the parts and filament I needed to create the prototype. I ended up using a Node MCU for the micro controller, two 18V solar panels for proposed power sources, two ultrasonic sensors for the autonomous features, 5 photo resistors to determine the ambient lighting, some 12V white LED strips for interior lighting, 2 RGB LED strips for directional lighting, 3 relays for controlling LEDS and the brushless motor, a 12V brushless motor and ESC, a 12V PSU for powering the prototype, and several other small parts.

Once most of the parts arrived I got to work on the 3d model. I used Fusion 360 to design all of the parts for this boat. I started by designing the hull of the boat and then moved upwards designing each part as I went along. Once I had most of the parts designed I put them all into a assembly to make sure they would fit together once they were manufactured. After several days of designing and tweaking it was finally time to start printing. I printed the hull in 3 different pieces on my Prusa Mk3s and printed the solar mounts and hull covers on my CR10s. After several more days all of the parts where finished printing and I could finally start to put it together. Below is another section of my research paper where I talk about designing the boat.

" Once I had a good idea of the final design, I moved on to Computer Aided Drafting or CAD, which is a process that can be done using many available softwares today. I used the software Fusion 360 to design the parts I would need to manufacture for my prototype. I designed all of the parts for this project first, and then assembled them in a virtual environment to try and work out any problems before I started to print out the parts. Once I had a finalized 3D assembly, I moved on to designing the electrical systems needed for this prototype. I wanted my prototype to be controllable through a custom designed app on my smartphone. For my first part, I chose the Node MCU microcontroller. The Node MCU is a microcontroller built around the popular ESP8266 Wifi chip. This board gives me the ability to connect external input and output devices to it that can be controlled remotely through its Wifi interface. After finding the main controller for my design, I moved on to choosing what other parts would be needed for the electrical system. To power the vessel, I chose two eighteen volt solar panels that would later be wired in parallel to provide an output of eighteen volts along with double the current of an individual solar cell due to wiring them in parallel. The output from the solar panels goes into a charge controller. This device takes the fluctuating output voltage from the solar panels and smooths it out to a more constant twelve-volt output. This then goes into the battery management system, or BMS, to charge the 6, 18650 lipo cells wired with two sets of three cells wired in parallel, then series. This configuration combines the 4.2 volt capacity of the 18650 into a 12.6 volt capacity pack with three cells. By wiring another three cells set in parallel with the previous pack, the total capacity is doubled giving us a 12.6 volt battery with a 6,500 mAh capacity.

This battery pack can output twelve volts for the lighting and brushless motors. I used a step down inverter to create an output of five volts for the lower power set of electronics. I then used three relays, one to turn on and off the interior lights, one to change the color of the external lights, and another to turn on and off the brushless motor. For the distance measuring, I used two ultrasonic sensors, one for the front and one for the back. Each sensor sends out an ultrasonic pulse and can read how long it takes that pulse to return. From this, we can figure out how far an object is in front of the vessel by calculating the delay in the return signal. On the top of the vessel I had five photoresistors to determine the amount of light present in the sky. These sensors change their resistance based on how much light is present. From this data, we can use a simple code to average all of the values, and when the sensors read an average value of low light, the interior lights will turn on. After figuring out what electronics I would be using, I started 3d printing the parts I had previously designed. I printed the hull of the boat in three pieces so it could fit on my main printer. While those were printing, I moved on to printing the solar mounts and deck on another printer. Each part took about one day to print, so in total there were about 10 days of straight 3D printing to get all of the parts I needed. After they were all done printing, I assembled them together in smaller parts. I then installed electronics such as solar panels and LEDs. Once the electronics were installed, I wired them all up and finished assembling the printed parts. Next, I moved on to designing a stand for the prototype. This stand was also designed in CAD and later cut out of MDF wood on my CNC machine. Using the CNC, I was able to cut out the required slots on the front panel for attaching curtain electronics. I then mounted the prototype onto the base and the physical assembly was complete. Now that the prototype was fully assembled, I started working on the code for the NodeMCU. This code is used to tell the NodeMCU which parts are hooked up to which input and output pins. It also tells the board what server to contact and what Wifi network to connect to. With this code, I was then able to control certain parts of the prototype from my phone using an app. This is similar in a way to how the final design would be able to contact the main docking station to receive the coordinates for its next stop, as well as other information, like where the other vessels are and the expected weather for that day."

Ok so now we are at my favorite part, the assembly. I love building things so finally being able to put all of the parts together and see the final results got me pretty excited. I started by putting together all of the printed parts and super glued them together. I then installed the electronics like lights and solar panels. At this point I realized there would be no way I could fit all of my electronics inside of this thing. That is when I got the idea to CNC a stand for the boat to make it look a little better as well as give me a spot to hide all of the electronics. I designed the stand in CAD then cut it out on my Bobs CNC E3 in 13mm MDF. I then screwed it together and gave it a coat of black spray paint. Now that I had a spot to stuff all of my electronics I continued on with the wiring. I wired everything up and installed the Node MCU (pretty much a Arduino Nano with built in WiFi) and made sure everything turned on. After that I wrapped up the assembly and even got to use my schools laser cutter to cut out the safety railings with some cool engravings, thanks again Mr.Z! Now that we had a finished physical prototype it was now time to add some magic with coding.

For the coding I used the Arduino IDE to write some pretty simple code. I used the basic Blynk sketch as a starter so I would later be able to control some of the parts from the Blynk app. I watched many YouTube videos and read lots of forums to get this thing to work. In the end I wasn't able to figure out how to control the brushless motor but got everything else to work. From the app you could switch the direction of the craft, which would switch the colors of the red/green LEDS, turn on/off the interior lights, and get a live data feed from one of the ultrasonic sensors on the front of the display. I definitely slacked off on this part and did not get nearly as much done on the code as I wanted but it still ended up being a neat feature.

It is done! I got everything assembled and working just barely before the science fair dates. (Stereotypical procrastinator) I was pretty proud of the final product and couldn't wait to share it with the judges. I dont have much else to say here so I will let past me explain it better. Here is the conclusion section of my research paper.

"Once the vessels and docking stations are created, the solution is underway. Each morning the vessels would start their routes through the waterways. Some might go through the canals in the cities, while others travel the marsh lands or ocean lines. While the craft is going through its route, the filtering skimmer will be down, allowing the filters to start their work. The skimmer will direct the floating algae and debris into the filtering channel. Once inside, the water is first run through a mesh filter to remove larger particles and debris from the water. The removed material will be held there until the chamber is filled. After the water has made it through the first filter, it then goes through the permeable membrane filter. This filter uses small, permeable holes to only allow permeable water through, leaving impermeable materials behind. This filter is used to extract the impermeable fertilizer material out, as well as excess nutrients from the algae growths. The filtered water then flows out the back of the boat back into the waterway where the vessel is filtering.

When a vessel reaches its designated docking station, it pulls into the berth. After fully docked, two arms will attach to the side of the boat to hold it steadily in place. Next, a pipe will automatically rise up from under the boat and attach to each waste disposal port. Once secured, the port will open and a pump will turn on, sucking the collected material out of the boat and into the docking station. While all of this is happening, passengers will be allowed to board the vessel and find their seats. Once everyone is onboard and the waste containers have been emptied, the craft will be released from the station and will start on another route. After the waste has been pumped into the docking station, it will be sifted again to remove large debris like sticks or trash. The removed debris will be stored in containers for later recycling. The remaining sifted algae will be taken to the central docking station to be processed. When each smaller docking station fills up its algae storage, a worker will come to transport the algae to the main station, where it will be refined into a biodiesel. This biodiesel is a renewable source of fuel as well as a profitable way to recycle the collected nutrients.

As the boats continue to filter the water, the nutrient contents will be reduced. This reduction in the excessive amount of nutrients will lead to smaller blooms each year. As the nutrient levels continue to drop, the water quality will be monitored extensively to ensure the nutrients remain at a constant and healthy level needed for a thriving environment. During the winter seasons when the fertilizer runoff is not as potent as the spring and summer times, the boats will be able to control the amount of water that is being filtered to ensure there is always a healthy amount of available nutrients. As the boats run through the routes, more and more data will be collected to more efficiently determine the sources of the fertilizer runoff and what times to prepare for higher nutrient levels. Using this data, an efficient schedule can be created to prepare for the fluctuation brought about by the farming seasons."