It was the 2023 Olympus Rover Trials and the newly formed Team Atlas were ready to compete in one of the most exciting events UKSEDS has to offer. The mission: build a rover to retrieve cargo from a drop site to basecamp on Mars (well imagine you are on Mars anyway).
The competition started all the way back in October 2022 when the first stage of the competition required us to produce a PDR (Preliminary Design Review) of the rover. This was out first chance to be creative and come up with all sorts of exotic designs and solutions. We discussed many different solutions from a very simple rover that had a hook attached to a flipper to pick up cargo, a rover that would drag along a platform that it would winch up into a storage area and finally a rover with a robotic arm. We decided to go with the best looking design which of course was the rover with the robotic arm.
However, the PDR was not only about producing a pretty drawing. It was about selecting the best materials and standard components and for this we used trade-off tables to decide the best component.
The design we came up with at the end of the PDR was a rover that has an arm with 5 degrees of freedom, driven by a rechargeable nickel metal hydride battery and is driven by 6 Walfront 12 V electric gear motor’s, all controlled by Laptop that is connected to a Raspberry PI via WiFi. The Raspberry PI sends camera data to the Laptop and controls the Arduino teensy which then controls the robotic arm and drive.
As amazing as this sounds, along came the CDR where we had to get a little more realistic. The major changes were losing a degree of freedom on the robotic arm, using 4 motors instead of 6 and changing the method of communication. Now we would use an RC remote control with an ESC to control the rovers drive and then use a Bluetooth App to control the robotic arm.
Again this all sounds good in theory, but in practice… things go wrong. This time it was the communication. We could not get the Bluetooth to work with the app despite our best efforts and eventually went for an ESP32 which wasn’t a bad choice wither since Wi-Fi modules tend to have a better range. As soon as we switched the arm was working like a charm.
As for the rest of construction various design changes had to be made. The suspension system had to be redesigned and we had to change various other materials.
While our workmanship may not have been “cutting-edge”, it was nonetheless we got it built in time and it was fully functional by the end.
Until.
Disaster. The back wheels broke off. This was one day before the competition. The fracture had occurred between the back the motor-wheel connector and it snapped under the weight of the rover. Fortunately, we were able to attach some larger wheels to replace them which probably was a good thing. Since this would have given better traction on the loose Mars Sand.
We were wrong. You see even with the larger back wheels we simply did not have enough contact area with the ground nor enough torque to move across the Martian Sand. So while it wasn’t a victorious day at the Mars Yard we still learnt plenty about how to design for Mars. As well as this we were given the privilege to tour their facility which was incredibly inspiring.
Day 2 of the competition was held at RAL Space. This company also did cutting-edge work with satellites and in fact they built the cooling system for the Mid Infra-Red Instrument on the James Webb Telescope. The completion however was to survive a vibration test where the rover would be shaken to a frequency of 100Hz to see what damage it took. Our rover however did not survive past 20Hz. This was due to the legs of the rover being quit quite long and not being tightly held by the suspension.
Overall our team learnt quite a few things about engineering, namely be sure of what it is you are making before making it. Too often we would start building things and later find out plan would not work in real life. Despite that, there were many good takeaways. For example, nothing broke during the first day of the competition and despite the acrylic box breaking during the second day of the competition, nothing electrical failed. For a first attempt, we would say it wasn’t too bad.
Finally, we would like to thank a number of people who helped us every step of the way. We would like to thank Amir and James for putting up with us in the hackspace and helping us throughout the build. We would like to thank Terry for letting us use his lab and do all the pipe bending there. We would like to thank Karim and Jordan for always being there at the tech hub whenever we needed a component. And of course we would like to thank Chris. We simply could not have done this project without his support on getting all the electronics working and teaching us so much along the way. Finally, we would like to thank the UKSEDS team alongside all of the sponsors, especially RAL Space and Airbus.