The Harsh Climate of Outer Space: Testing our rover Alira against extreme hot and cold.
Alisha Wong, Laura Kaastra
Webber Academy
Grade 7
Presentation
Problem
Problem
Robots and rovers cost a lot of money. NASA rovers cost between 2.5 billion and 3.2 billion dollars per mission! Now, this may not be a problem for NASA and other big tech companies but for the average person, spending thousands of dollars on a homecare rover or a work rover does not seem reasonable. Many people can't afford to buy and repair a rover or a robot which could help them improve their lives. Small, starting companies might want to utilize robots but due to their high prices it becomes a no. This is not fair because everyone should be able to get the same access to technology without worrying about breaking their bank accounts. For some people living in lesser living conditions owning robots could improve their lives in more ways than one but because of the cost it becomes a hard no.
Objective
We are building an analogue control rover to improve others lives. Our project proves that you don't need high-tech, fancy equipment to build a fully functioning rover. We are doing this project so that others can use our rover Alira, in any way they see fit. From seed planting to scientific expeditions, Alira can perform just as well as a NASA rover! Our rover is made from low cost equipment. Most home rovers can cost over 20,000 dollars to 30, 000 dollars. We designed a rover that can help others without being complicated or costly. This can improve people of today's lives because due to inflation the price of amenities and pleasure items are skyrocketing and having a rover can help in many ways. In short we wanted to help people by using technology that is low-cost, easily found, and high quality!
Method
Materials
- 12 volt electric motor/ 50 RPM (4)
- 12 channel remote control relay (1)
- 8 mm shafts (4)
- 8 mm bearings (4)
- 8 mm flange (4)
- 6 x 1.5 inch rubber tires (8)
- 5 pin automotive relay (8)
- DIN connectors (20)
- Compact splicing wire connectors (as many as we need)
- Terminal Block (4)
- Various colours of 12 and 14 gage wire
- 20 amp power batteries (2)
- 8 mm coupler (2)
- 4 position analog joystick
- ⅜ inch puck board (pieces were cut by Iebeling Kaastra and Rob Lowen using a table saw. This was done using a cardboard model template.)
- Table Saw
- Measuring Tape
- Black Marker
- Ruler
- Original puck board (2x4’)
- Cordless Drill
- Cordless Impact Driver
- Quarter Inch Metal Screws
- 90 Degree Angle Brackets
- Set screws
Procedure
- Gather Materials
- Lay out the materials
- Use the Cordless Impact Driver and the Cordless Drill to attach the puck board together using the ¾ Inch Metal Screws
- Drill holes for the shafts and the bearings
- Determine the shaft height based on the shape of the electric motor
- Drill holes for a 8mm shaft
- Measurements are 3 ¾ inches from the end and 1 ¾ from the bottom
- Screw bearing into the outside of the chassis using the shaft as a guide
- Drill pilot holes for each of the bearing screws
- Insert ¾ Inch Metal Screws in to the holes in the bearing
- Attach an OSB block onto the bottom of the rover
- Screw it through the bottom and ensure that it covers the whole bottom
- Screw in a 2 x 6 wooden block in the middle of the rover
- This will be used to support the terminal blocks
- Hot glue the 8 relays next to each motor
- 2 relays should be associated with each motor
- Use 1 inch screws to attach the 3 terminal blocks to the center wooden piece
- Attach the couplers to each motor
- Push the shaft through the bearing and attach it to the coupler using the set screws
- Use the splicing wire connectors to connect the white wires from the 2 relays
- Attach one of the white wires to the negative terminal block
- Repeat steps 20-21 exactly for the blue wires
- Repeat steps 20-21 for the red wires but attach it to the positive terminal block instead
- Connect the black relay wires to the motor leads (test for the rotation direction later)
- Connect the yellow wires (logic wires) to the center terminal block
- Each one has its own separate connection
- Chanel one on the remote is left turning forwards
- This means the right side motors are going forward and the left side motors are stopped
- Chanel two is right turning forward
- This means the left side motors are going forward and the right side motors are stopped
- One and two pressed at the same time are straight forward
- Three is left turning backwards
- This means that the right motors are going backwards and the left motors are stopped
- Four is right turning backwards
- This means that left motors are going backwards and the right motors are stopped
- Three and four pressed at the same time are straight backwards
Background Research
Our project is to make a low cost, analog rover that can be used in a variety of ways. Robots used for household tasks normally cost between $20,000 to $30,000. Many individuals cannot afford to have a robot that costs that much. Projects like Bill Gates "composting toilets" are meant to find a new innovative solution to an already existing item. We are doing the same. A website called Raph Rovers is an example of high quality rovers. The rover is just a simple machine. It does not have fancy parts attached to it. But, compared to our rover, Alira, which cost around $650 to make, Raph Rovers cost around $20, 350.00. Another comparable website is the Jet Propulsion Laboratory at the California Institute of Technology. There you can build a “mars” rover that you can control and improve upon. Their rovers are better quality because they are built by a team of scientists but they cost $25, 000. Before we build our rover we need to first understand the key definitions that will educate us so that we already have existing knowledge before we start building. An analogue controlled rover means a rover that requires continuous signals to perform tasks instead of digital programming like 0's and 1's. Our rover uses wires to connect the pieces instead of computer programming. A digital rover uses programming. The reason why we are not creating a digital rover is because it generally costs more to build and it is incredibly complicated to repair. The remote relay is the piece of the rover that receives the signal from the remote. According to Schneider Electric "Relays provide automated and remote control. This makes them ideal for power distribution and industrial applications." A five pin automotive relay is the type of relay we are using in our rover. It is a standard 12 volt relay that contains five terminals: 87, 87a, 86, 30, and 85. Our rover uses wires to connect the pieces instead of computer programming. A digital rover uses programming. The reason why we are not creating a digital rover is because it generally costs more to build and it is incredibly complicated to repair. The remote relay is the piece of the rover that receives the signal from the remote. According to Schneider Electric "Relays provide automated and remote control. This makes them ideal for power distribution and industrial applications." A five pin automotive relay is the type of relay we are using in our rover. It is a standard 12 volt relay that contains five terminals: 87, 87a, 86, 30, and 85. A Relay Switch Normally Closed (NC) is a switch that is in its on state until it is turned off. We also need to be educated about the battery. A lead acid battery works best in 25 degree celsius weather. If the temperature reaches between 33 and 35 degree celsius than the battery life will get reduced. A fully charged battery only freezes at -60 degree celsius but a battery that is low on battery is mostly water and can freeze at 0 degrees celsius. We will make sure to have all our batteries at full so they do not freeze during testing.
Analysis
Observations
During the testing, the couplers came loose and the wheels did not have have any friction. We fixed that by drilling holes into the couplers and the shafts and inserting 6-32 bolts to keep it in place. We also drilled a hole through the flange and the shaft and inserted a 6-32 bolt in the hole.
When we went uphill to test the rover, the wheels kept getting stuck in the snow and would not move.
When we drove the rover in a lot of snow, it would get stuck while if we drove the rover in a little snow, the wheels would spin as there was no traction and that caused the rover to be slower.
The batteries performed very well and could run a long time.
Analysis
The remote control worked very well, the logic worked very well, the relays could hold up for a long time, and the batteries were a very good choice because they were very powerful and could keep the rover running for a long time. Our motors were not powerful enough to turn the rover. The drivetrain and the tires were difficult to keep tight and stop from coming apart. The rover was likely too heavy for the torque of the motors.
| Temperature (℃) | Terrain | Voltage (V) | Time (mins:secs) |
|---|---|---|---|
| -1 | Flat and Paved | 13.30 | 1:22 |
| -1 | Upslope and Paved | 13.23 | 1:39 |
| -21 | Flat and Paved | 13.16 | 1:24 |
| -21 | Paved Snow | 13.16 | 1:31 |
| -21 | Upslope and Paved | 13.18 | Unfinished |
Conclusion
Conclusion
This is an innovation project because we are trying to make a rover to do household chores by making it more affordable and with everyday materials.
The procedure is not that challenging as we just had to connect all the wires and screw pieces together. Also, the materials are all low cost so it is more affordable.
The rover can also go on all terrains such as flat and paved, paved snow, and upslope and paved. For flat and paved on a warmer temperature, Alira went 0.30 m/s which is the fastest speed. The slowest speed Alira went was 0.25 m/s on upslope terrain on a warm day. One of the tests, however did not finish which was the upslope terrain on a cold day.
Improvements
- We could switch from 10 inch to 6 inch wheels. This would increase the torque by 40 percent and help the rover turn.
- We could add suspension to improve wheel traction.
- We could insulate the battery to improve cold-weather performance.
- We could use lighter materials like composites which would increase run time.
-
We could have used one relay for each motor. These are called double pole, double throw (DPDT). It contains two inputs and two outputs.
-
We could connect the motor and the flange directly to the tires. We would then mount the motor on the outside of the chassis and insert the screws from the inside so we could drop the motor lower allowing it to have more clearance. This would make it simpler and reduce the cost. There would also be fewer parts.
- We could use only one battery to reduce the weight and the cost.
Citations
Astronomy.com. “Sojourner: NASA’s First Mars Rover.” Astronomy.com, https://www.astronomy.com/space-exploration/sojourner-nasas-first-mars-rover/.
Business Insider. “A $350 Toilet Powered by Worms May Be the Ingenious Future of Sanitation That Bill Gates Has Been Dreaming About.” Business Insider, January 13, 2019, https://www.businessinsider.com/bill-gates-foundation-helps-invent-tiger-toilets-powered-by-worms-2019-1.
Fictionlab. “Raph Rover from Fictionlab – The Creators of Leo Rover.” Fictionlab, https://fictionlab.pl/raph-rover/. JPL (Jet Propulsion Laboratory). “JPL’s Open Source Build-It-Yourself Rover.” JPL Open Source Rover, https://jplopensourcerover.com/#!/home.
KEYi Technology. “How Much Does a Humanoid Robot Cost? 2025 Price Breakdown & Models for Sale.” KEYi Robot, https://keyirobot.com/blogs/buying-guide/how-much-does-a-humanoid-robot-cost-2025-price-breakdown-models-for-sale. Merriam-Webster. “Digital.” Merriam-Webster.com Dictionary, https://www.merriam-webster.com/dictionary/digital. NASA. “Mars Facts.” NASA Science, https://science.nasa.gov/mars/facts/.
NASA. “Mars Pathfinder.” NASA Facts, https://mars.nasa.gov/internal_resources/815/.
NASA. “What Is Mars? (Grades 5–8).” NASA, https://www.nasa.gov/learning-resources/for-kids-and-students/what-is-mars-grades-5-8/.
Schneider Electric. “What Is the Difference Between Relay and Switch?.” Schneider Electric eShop, January 31, 2024, ** https://eshop.se.com/in/blog/post/what-is-the-difference-between-relay-and-switch.html.**
Acknowledgement
Laura
I would like to thank my dad who helped me during the whole building process and who guided me every step of the way. I would like to thank my mom who helped me formulate our posture board and encouraged me to try my best.
Alisha
I would like to thank my dad who helped time our rover and take pictures for our poster board. Also, I would like to thank both my parents for helping me make the graphs and continued to support and help me to make it the best I could.
