EPFL Xplore team wins second place at European Rover Challenge

On this occasion, the team made up of 70 Bachelor's and Master's students from EPFL claimed a spot on the podium for the second year in a row, placing third on their first participation last year and rising to second place this year.

No small feat for the Lausanne team, who earned further recognition with a Special Prize rewarding the best performance in the navigation task.

From Poland to Mars

Launched in 2014, the European Rover Challenge is a competition which not only sets an exciting goal for engineering students, but is also increasingly recognized as a testbed and benchmark for planetary robotics.

The competition revolves around a series of five complex tasks designed to be as close to real conditions as possible thanks to a setting built to perfectly reproduce the many geological features found on Mars.

Known as the “Mars Yard”, this unique track gets redesigned every year to integrate replicas of new portions of the Martian landscape.

This year, organizers found inspiration in the Martian plains of Utopia Planitia and Elysium Planitia, providing students with craters, dunes, dry riverbeds and solidified lava.

This simulated Red Planet was the backdrop against which the 16 qualified teams (out of 64) were to demonstrate the abilities of their prototypes. First in a navigation task, which required mapping and planning the itinerary of their rovers, followed by a scientific exploration task, a probing and collection task, and a maintenance task, in which the rovers had to manipulate switches and commands mounted on a panel and perform electrical parameter measurements. Finally, to cap off this intense series of challenges, students were asked to present their project to a jury of experts.

Astra: EPFL’s students’ second-generation rover

For its second participation in the European challenge, the team completely reviewed its project. Based on the experience acquired with their first-generation rover—Argos—the students collectively dedicated more than 25’000 hours improving their concept to give birth to Astra.

“If you were to compare Argos and Astra, you’d think that two entirely different teams had conceived and built them” said Daniel Tataru, Master’s student in Mechanical Engineering and Space technologies.

“Participating in the European Rover Challenge in 2021 with our first-generation rover allowed us to identify its strengths, weaknesses, and major aspects we could further improve. Without the experience gained on Argos, Astra wouldn’t have seen the light of day.”

This bold decision paid off. The robustness of the navigation software developed by the students enabled the EPFL team to stand out with the special prize rewarding the best autonomous navigation algorithms.

Putting tremendous efforts into reducing the play in their robotic arm on the one hand, and improving their rover’s scientific capabilities on the other, led to high scorings in the other tasks.

"Under a year, we went from manual control to navigation autonomy thanks to new sensors and a much larger navigation team. This was also supported by a completely redesigned structure allowing the rover to climb obstacles up to 30 centimeters and slopes up to 45 degrees."

This experience was made possible thanks to the support of the MAKE educational initiative which provides students with a network of state-of-the-art infrastructure and equipment and mobilizes expertise from members of the EPFL teaching community, from coaches, and from the heads of professional workshops.

It is through this scheme that the Xplore team was able to conceive and build its prototype from scratch.

"We were able to remanufacture some parts that were insufficiently rigid in our suspension mechanism. We also took advantage of the SPOT’s (EPFL's brand new Makerspace) huge open space to test our rover’s autonomous navigation and obstacle avoidance package. Furthermore, having access and direct contact with EPFL's professional workshops was critical in order to actually machine more complex parts, which wouldn’t have been possible otherwise."

"We are always learning and often need advice and expertise for the challenges we are facing. Be it the professionals helping us design and manufacture our parts, coaches guiding us to best practices when prototyping and testing new designs, or professors helping us spot potential issues during our design reviews, it all contributed to our success." said Daniel Tataru

Already anticpating their next feat, the students have specific objectives in mind: "the first platform did not have the necessary modularity to allow for technical developments in the years to come," explained Quentin Delfosse, a Master's student in Robotics and Space Technologies. "With this new concept, we are pushing the limits. This does not mark the end of the adventure and we have already identified the improvements on which we will now focus in order to exploit our rover’s full potential.