By Will M
Design Iteration #1
Our chosen location for the Fusion PEP assignment was the celestial body known as Titan (Saturn’s largest moon). We chose this celestial body due to the many natural features such as an atmosphere, large hydrocarbon reserves, and being able to easily create and sustain oxygen production via the materials and compounds spread along the moon’s surface. However their were also many challenges we faced in the theoretical science portion of our projects which we addressed in our definition statement.
“When designing a vehicle suitable for Titan, the critical problems we must consider are its ability to accommodate 4 people and its machinery under extreme temperatures of -180°C, hold sufficient energy to travel distances of 10km at a time, be able to produce oxygen, and have sufficient traction to grip Titan’s unique surface of ice, dunes and pebbles alongside combating the lower gravity similar to the moons.”
From our tests we hope to find our vehicle efficiency which we will calculate using a video analysis software. From this data we hope to find the optimal ratio from weight to size to battery power for our vehicle to successfully traverse Titans complex and sandlike terrain. We also hope to find the efficiency of spiked treads on sand. We will be testing this by creating an accurate terrain replica of titan’s surface and testing our vehicle’s movement capability’s. This terrain was replicated by both a slippery white board and a board covered in sand.
After our research and construction of our PEP statement we made a sketch iteration of our design before I finished our BOM and began experimenting with the robotics components of our design while another group member built the skeleton design of our vehicle. Throughout the early stages of this project I demonstrated leadership skills by analyzing my groupmates strengths and having them work on certain parts of our project while at the same time guiding the creation of the CAD design and creation of our BOM (Bill of Materials) Table.
Below are photos of our original CAD design alongside our test plan. This CAD design was designed to be 3D printed with all of the components stored inside the large base. For a practical use we implicated a raised hexagonal head to serve as a lookout and control center for our vehicle.


Our tests were designed to allow for traction to be tested on terrain similar to ice sheets and shallow sand. We will use a piece of plywood covered in kinetic sand made to implicate dunes to recreate Titan’s desert. The dunes will allow us to test whether our vehicles spiked treads could traverse vast deserts. We will use a whiteboard to test the spiked treads traction along a slippery surface.
Ontop of our designs body and functions we needed to create an arduino system to balance the energy between our 4 motors. Our system relied on a motor driver dividing up power between our motors to prevent an overload that could possibly cause our wires to light on fire. This motor driver took inputs from our arduino board and moved the motors when a button was pressed an odd amount of times.
Below is a digital rendering of our circuit in tinkerCAD and a link to our arduino code

https://docs.google.com/document/d/1CTgDRBPVeu1g_BPqWoKPODBKnu6dfULV9sHNiDDgZ94/edit?usp=sharing
The Problems
Although my group made impressive progress in our planning stages and had set our eyes on an ambitious design we soon realised we could have overcomplicated our design. Unfortunately our first vehicle prototype did not function on our first test day due to four main problems which had to do with our code, enclosed design, weak axels, and our original print mistake. Our code did run smoothly in our online simulation however when it came to building our prototype we found out the motor driver was unable to divide power evenly and simply just overloaded causing the circuit to be completely immobile. Following this failure we tried to pivot last minute and were unable to fix this problem for this prototype. However, we gained inspiration on how we could make the arduino code the minimal viable product (MVP) that still solved our problem. Our enclosed design made it very difficult to put together the circuit inside of the vehicle causing us to waste time trying to configure our design. As we managed to put together our design we soon realised that the wooden axels were beyond weak and proved to be unable to hold the wheels weight causing them to just snap and fall off. Our last problem had to do with a small problem we faced orignially being a misdesign in our vehicle body. Originally we were meant to have the motors come out of the bottom of the vehicle but our file wasn’t saved properly and this big hole dissipeared. We then spent a long time trying to drillpress holes in the side of the vehicle only for the wheels to barely touch the ground deeming our vehicle non functionable. These many problems and the crushing feeling of failing on test day motivated my group and I to knock our next iteration out of the park.
The First Test
Come the first test day my group and I knew our vehicles ability to function would be abysmal but we at least hoped it could move with some last minute adjustments. After going through our test it would be safe to say our vehicle did not function however, this didn’t mean we failed to make observations and learn from our mistakes. To fully understand how we could improve our vehicle design we first had to ask the question, what went wrong?
Our poor design choice of using wooden axels and attempted pivots only weakening the vehicles ability to function led to many other problems to arise deeming our vehicle fully immobile. We also noticed our treads not being able to hold the hot glue inside them, preventing us from attaching our treads.
Onto the flip side we noticed our motors and batteries worked due to our minimum viable product design. We also came our of this test knowing how we could improve our vehicle. These improvements consisting of using metal axels in the motors, using rubber bands and ridges in the wheels for traction, and using a more open body allowing for us to access components more easily.
The Final Prototype
Our final solution was a collective of all of our improvements planned out following our first tests failure. To fix our issue we originally faced with our treads not attaching to the wheels we decided to make a new wheel design printed out of a stronger PLA with a ridge meant to fit a rubber band allowing for better traction. We also decided to drop a motor and take our vehicle from eight wheels to six. To support our vehicles immense weight we made metal axels by using an electric saw

Our new vehicle body was laser cut out of plywood allowing us to reduce vehicle weight hence increasing our vehicles efficiency. We also noticed our new prototype experiencing problems when attempting to go straight so we added some square dowels on the edges of the vehicle to spread out weight which somehow fixed our vehicles problem relating to its traverse path.

The Final Test
During our final test we noticed our vehicle exceed our expectations by working flawlessly along all of our tested terrains as well as noticing our vehicle could climb inch high walls and could traverse a rocky surface in which the vehicle was unintended to do. Our vehicles counterweight and long design allowed for the vehicle to stay stable along different terrains as well as proving to be efficient from our test data in our video analysis app.
Below is a photo of our graphs and data taken from our video analysis tool and a link to a spreadsheet covering our data.
https://docs.google.com/spreadsheets/d/1FYDMfTBwXiNRTjw0pYdNjb8K2Ooo73hhsJo8KK3AR_I/edit?usp=sharing
Sandy Terrain Graph covering movement and Speed

Icy Terrain Graph covering movement and Speed

After our main tests some other quick measurements were taken of the vehicles weight, voltage, and amps. These measurements came out as 506.7 grams, 7.34 volts, and 0.52 amps.
Below are links to some videos of our vehicle.
Data Analysis
From our data we were successfully able to determine our vehicles speed across both terrain’s which was listed when we made an average of the collective speed in both in/s and m/s in the video analysis tool. From this we were able to find out that on the sandy terrain our vehicles velocity was 0.28 m/s on sandy terrain and 0.34 m/s on the ice terrain. After we have some basic data relative to our vehicle’s speed we now must find the vehicles energy efficiency. Now what is energy efficiency? Energy efficiency is using minimal energy to complete a task. In our case the energy efficiency percentage is counting how much of our energy is being used to its capability. For a project like this the energy efficiency could range from 0.1%-1%. To find our vehicle’s energy efficiency we first have find values for both input and output energy. The efficiency formula is output over input energy. Input energy is by definition the total amount of energy applied to a system so in our case we would find this by multiplying our voltage by our amps. By multiplying our voltage of 7.34 volts by our amps of 0.52 we are able to find out that our vehicles input energy rounds up to 3.82 joules of energy. To find our vehicles output energy we first need to understand what output energy is. Output energy is the total energy of kinetic, thermal, and light energy. In our case no thermal or light energy is being emitted meaning our vehicles output energy=its kinetic energy.
To find kinetic energy we must use the kinetic energy formula which is

After putting in the mass of our vehicle which is 506.7 grams and the average velocity of our vehicle across both the ice surface and sand surface we can simply multiply everything together to find the kinetic energy. By adding up the two velocity’s and dividing by two we can find the average velocity across all terrain of our vehicle. (0.28 + 0.34)(1/2)=0.31 so our vehicle’s average velocity is 0.31 meters per second. Now that we have the velocity we can put everything altogether giving us

After rounding to three decimal points we find the output energy = 0.0243 joules. Lastly to find our vehicles efficiency we will do output over input which is 0.0243 divided by 3.82 which gives us about 0.00636. Lastly we multiply 0.00636 by 100 to turn it into a percentage which means our vehicle’s efficiency is around 0.636%.
Below is a link to the equation editor I used to formulate my calculations.
Conclusion
From this project I’ve come to learn so much about physics, vehicle design, celestial bodies, and being able to make simple and smart implications to projects. I can draw that with other ways to solve some restraints such as travel time our vehicle could traverse Titan. We could also use the property’s of hydrocarbons to create large amounts of energy powering the vehicle and would have to find a way to cause electrolysis with ease allowing for a sustainable oxygen source. Overall I would call my groups attempt at our planetary exploration project to be quite successful.
Although when looking back this project was deemed successful that doesn’t mean our vehicle couldn’t have been better. Based on what I’ve learned about energy efficiency and vehicle design I would have liked to make the vehicle’s body be lower to the ground with a triangular design to increase vehicle balance and to lower the vehicle’s weight. This change alongside moving the heavy components more centrally would allow the energy efficiency to rise making our vehicle even more suitable for Titan. Although if a new environment and new redesign would be to occur I believe it would be quite interesting to work with a vehicle that tunnels under deep sand deserts via air propulsion and a large drill pushing sand.
Lastly, throughout this project I’ve learned that the more times you test the more you can learn which is a valuable lesson I will be carrying with me into my personal project.
Below is a link to my AI transcript
https://docs.google.com/document/d/13kwVtCg7u140V7MvsbhFKiusHy642KC1711NxKsERBY/edit?usp=sharing
Please note that AI use was quite minimal in this portion of the PEP project.



















