Posted to News on 30th May 2025, 18:00
Innovative actuators for active exoskeletons
For the active exoskeleton of the RISE project carried out by TU Berlin students, the Nabtesco Precision Europe's branch in Limburg co-developed six actuators that help to mobilise hips and knees.
Exoskeletons are mechanical assistance systems that are worn directly on the body to support or enable human motions. They are used in industry, logistics, craft trades, and the health sector, as well as medical rehabilitation and ergonomic workplace design. There are three types: passive (purely mechanical), active (with motor support), and hybrid exoskeletons.
However, the high-level replication of a humanoid motion apparatus is a true challenge - and can be achieved only with compact, zero backlash gears. The students involved in the RISE (Research and innovation in student exoskeleton development) project at TU Berlin therefore chose drive solutions from Nabtesco Precision Europe in developing their active exoskeleton.
Nabtesco Precision Europe, with a family of companies that combines mechanical, electronic and digital expertise, co-developed six actuators for the exoskeleton at the Limburg location - three for each side of the body (1x flexion/extension and 1x abduction/adduction) and one on the knee (flexion/extension). Altogether, three types of actuators are used in two different constructions (knee/hip) with several gear ratios.
The primary focus was on availability (development of the entire exoskeleton took just 2 years), reduction of development and design effort on the part of the students, as well as minimising mass and volume.
Maximum performance and safety
The electromechanical drives consist of strain wave gears, an electric motor, and position sensors, offering impressive performance in a minimal footprint. Innovative strain wave gears form the core of the actuators. The compact, backdriving precision gears are manufactured to automotive standards and feature absolute zero backlash, high efficiency, high torque density, and high overload protection.
In addition, they are maintenance free throughout their entire service life and score points for their low inertia, lightweight design, and quiet operation. This results in dynamic, precisely executed motions with maximum safety.
The exoskeleton was put to the test at CYBATHLON 2024 in Zurich - a contest in which teams from around the world accomplish everyday tasks using the latest assistance technologies - and took fourth place in the final round as the youngest team.
But the project is far from over. Further development of the exoskeleton is already in full swing. Active exoskeletons are a great opportunity for people with limited mobility, such as paraplegia, for example, or after a stroke, since they enable everyday motions like walking, standing, and climbing stairs.
