Cybathlon

During the Cybathlon championship – taking place outside Zurich, Switzerland – individuals with physical disabilities are set to compete against one another to perform everyday tasks using state-of-the-art technical assistance systems. Inside many of the competitors’ assistance systems are motor and drive technologies that provide high-power density and dynamics that allow each athlete to move.

As with robots and medical devices, electro-mechanical prostheses require drive systems to properly function. Cybathlon partner and Swiss drive specialist maxon develops and manufactures motors, gearheads, encoders, and controllers for assistance devices. maxon has supported the event as a partner since 2016 as the company’s mission mirrored Cybathlon’s aim to improve people’s quality of life.

Among other contributions, company trainees built a height-adjustable podium. This year, maxon will join the competition as a presenting partner. CEO Eugen Elmiger says, “We believe that excellent engineers with a curiosity for new things can make the world a better place. This is why maxon has supported the Cybathlon right from the start.”

Support, product development

As a presenting partner, maxon will be close at hand before and during the competition. Teams and pilots can visit their lounge in the Team Village to provide feedback that maxon will use in carrying out future developments for assistive technologies.

“Anyone who watches the Cybathlon competitions in Zurich will find that maxon drives and controllers are used in numerous pieces of equipment,” says Alessandra Keiser, project manager at maxon. “Sometimes it’s not so obvious, as the devices may be hidden away. Yet they are there, reliably doing their job, as you would expect from a trustworthy partner.”

Adaptive wheelchair

Design elements in the devices used in competition help users overcome everyday challenges by considering accessibility and ease of use in natural-looking details for prosthetics and easily accessible functions and buttons.

Developed by a team at Swiss startup Scewo, the Bro Wheelchair began as a student project for a robot to climb stairs and ride on two wheels. It now offers users more freedom and flexibility. Bro Wheelchair users can climb steps made of various materials. Whether going up or down, straight, or on a slight curve, Scewo Bro safely moves users from one place to another. There are also seat setting options to offer back, foot, and arm supports to suit individual needs.

“Our Scewo Bro drives on two wheels, which makes driving on lawns, sand, and forest paths, for example, more pleasant and easier,” says Tabita Rüegg, head of marketing & communication at Scewo. “Another advantage of our device, our wheelchair keeps the balance independently. This means that no torso stability is required from the user.”

At the last competition, the wheelchair did not meet expectations, failing due to an error in the software that caused the team’s wheelchair to stop at the first obstacle. Like competitors in every sport, Scewo engineers learned from their mistakes.

“At that time, we had mounted the restart button under the seat and unfortunately we did not consider that a wheelchair user logically could not reach it by himself,” Rüegg explains. “The biggest learning therefore: buttons that are easy to reach for the pilot.”

In response, new design elements have been incorporated for this year’s race, including more powerful motors and more stable software. In terms of driving experience, the team made significant progress compared to the 2016 prototype.

In the powered wheelchair race, a door must now be opened and closed again using a technical aid with an external energy source. The Scewo team is equipping its wheelchair with a robotic arm to complete this task. They are using maxon EC flat motors and an EPOS4 positioning controller. maxon is also offering support to the team via the Young Engineers Program (YEP).

“It’s clear to us that it takes far more than our device to create a barrier-free world,” Rüegg adds. “Nevertheless, we want to do everything that we can contribute with our knowledge and manpower. By taking part, we want to prove that our device is marketable and can also cope with challenging everyday situations.”

Drive technologies

According to Otto Ineichen, business development - medical at maxon, drives for adaptive devices such as exoskeletons must be lightweight, and low overall height is crucial. At the same time, however, high power density and dynamics are required, as motors must change speed frequently and quickly change rotation direction.

Incorporating these concepts to develop the most useful devices, every fifth team at Cybathlon will be using maxon motors. Some of them include:

SoftHand Pro – The team from the Istituto Italiano di Tecnologia and the Centro E. Piaggio of the University of Pisa is racing with pilot Maria Rosanna Fossati. Maria particularly appreciates the flexibility and simplicity of the bionic hand prosthesis and trains three times a week for the Cybathlon.

maxon products used: DCX 19, GPX 19

ALEX – The advanced lower extremity exoskeleton (ALEX) team consists of members from the Chinese company Fourier Intelligence and the University of Melbourne, Australia. The team has been developing an exoskeleton specifically for participation in the Cybathlon since February 2019.

maxon products used: Brushless EC 60 flat motor

Hermes – Founded in 2018, they are the first team from Greece participating in the Cybathlon. The team wants to develop a fully functioning exoskeleton for people with limited motor function. It’s being supported by maxon’s YEP.

maxon products used: Four exoskeleton drives – brushless flat motor with an encoder, three-stage planetary gearhead, EPOS-4 positioning controller

VariLeg enhanced – After Cybathlon 2016, ETH Zurich and the HSR University of Applied Sciences Rapperswil - found that their competences complemented each other perfectly, and they built a race exoskeleton. The team’s made up of students from different fields of study.

maxon products used: Four EC 90 flat motors

About the author: Michelle Jacobson is the assistant editor of TMD. She can be reached at mjacobson@gie.net or 216.393.0323

Cybathlon
https://cybathlon.ethz.ch

maxon motor
https://idx.maxongroup.com