“As soon as the project was presented, I knew it was the one for me,” says Shuaixin Qi. Since September 2018, the sixth-semester mechanical engineering student has been working alongside 14 other students to build a motorised exoskeleton that enables paraplegics walk. Qi is particularly thrilled to use his expertise to help people.
The project, called
VariLeg enhanced
, is one of the Focus projects that are offered to students in their fifth and sixth semesters by the Department of Mechanical and Process Engineering (D-MAVT). Anyone interested in participating has to apply. The projects are also open to students in the Department of Information Technology and Electrical Engineering (D-ITET) as well as those at a few other universities.
Focus projects demand a huge amount of time and effort. Students are presented with a complex technical challenge and are asked to develop a solution – with support from coaches and professors – in the space of just a few months. But the participants believe their efforts are worth it. Qi sums up what drives them: “We can gather practical experience for later on here in the sheltered university environment.”
Helping others
Qi’s colleague Michael Heid knew back when he started his mechanical engineering studies that an opportunity to work on a Focus project was not one he could pass up. Like Qi, of the seven projects to choose from, VariLeg enhanced appealed to him the most because of its social aspect. “It’s not just about building a robot or an even more efficient motor; with our project, we can help make a real difference to people’s lives,” he explains. The topic is of course intellectually interesting to him, but there is also a personal dimension as he has had to witness how accidents left several of his friends in wheelchairs.
This project represents the third generation of VariLeg. The first was also developed by a Focus team, back in 2014. Another student team designed VariLeg 2 for the ETH Zurich CYBATHLON in 2016. “Our goal is to further refine the exoskeleton so that we can enter it into the next
CYBATHLON
in 2020,” Qi explains.
Carbon makes it lighter
One major improvement the team made was to switch the majority of the components over to carbon in an attempt to make the exoskeleton lighter. They also designed each knee and hip joint to be controlled separately. “We are completely rewriting the programming,” Qi adds. Whereas the previous models relied on software developed by the team, this year’s group opted for an open-source solution. This solution is continuously refined by experts and has the advantage that it is always up to date.
Technology is not the only challenge facing the team, made up of 12 ETH students in mechanical engineering, electrical engineering and health sciences as well as 3 students from the HSR Rapperswil University of Applied Sciences. The group had to learn to operate as a team and develop their own workflows and organisational structures. In addition, taking decisions on their own was a new experience; up to this point, their studies had consisted primarily of carrying out assigned tasks with a clear path to the solution. For example, when the project began, Qi had hoped to find a standard solution for each of the various development steps. In the meantime, however, he and his teammates have learned that there is no such thing as a “standard” solution, and that regardless of how well they plan, nothing ever turns out quite as they expected.