Innovative solutions for active exoskeletons

Nabtesco Precision Europe GmbH is one of the world's leading specialists for precision gears and the global market leader in robotic gears, boasting unique experience and expertise in the development of mechatronic drive systems. For the active exoskeleton of the RISE student project at TU Berlin, the company co-developed six actuators at its Limburg (Lahn) site (Ovalo GmbH) that help improve hip and knee mobility.

Exoskeletons are mechanical assistance systems worn directly on the body that support or even enable human movement. They are used in sectors such as industry, logistics, skilled trades, and healthcare, and are used in areas such as medical rehabilitation and workplace ergonomics. A distinction is made between passive (purely mechanical), active (with motor support), and hybrid approaches. However, simulating a humanoid musculoskeletal system at the highest level is a real challenge – and can only be achieved with truly backlash-free and compact gears. The students of the RISE (Research and Innovation in Student Exoskeleton Development) project at TU Berlin therefore chose drive solutions from Nabtesco Precision Europe GmbH to develop their active exoskeleton.

Unique Mechatronic Systems Expertise

Nabtesco Precision Europe combines mechanical, electronic, and digital expertise within its corporate family and co-developed six actuators for the exoskeleton at its Limburg (Lahn) site, Ovalo GmbH – three per side of the body: two at the hip (1x flexion/extension and 1x abduction/adduction) and one at the knee (flexion/extension). A total of three actuator types are used in two different designs (knee/hip) and multiple ratios. The main focus was on availability (the development time for the entire exoskeleton was just two years), reducing the students' development and design effort, and minimizing mass and volume.

Compact actuators with maximum performance and safety

The electromechanical drives consist of a strain wave gear, electric motor, and position sensors, offering impressive performance with minimal space requirements. The heart of the actuators are the innovative strain wave gears. The compact, reversible precision gears are manufactured to automotive standards and are characterized by absolute zero backlash, high efficiency, high torque density, and high overload safety. They are also maintenance-free throughout their entire service life and boast low mass inertia, low weight, and low operating noise. The result is dynamic, precisely executed movements with maximum safety.

Active exoskeletons are a technology with a future

The exoskeleton experienced its baptism of fire at the Cybathlon 2024 in Zurich – a competition in which teams from all over the world tackle everyday tasks using the latest assistance technologies – and finished fourth in the final as the youngest team in the field. But the project is far from over. Further development is already in full swing. Active exoskeletons offer a great opportunity for people with mobility limitations, such as those with paraplegia or those suffering from a stroke, as they make everyday movements like walking, standing, and climbing stairs possible again.