PECM Issue 46 2020 | Page 79

SOLUTION Marsi Bionics selected the RLS Orbis encoder for its ATLAS exoskeleton and the RLS RM08 encoder for its MAK kneejoint exoskeleton. The Orbis encoder is a component-level absolute rotary encoder designed for space constrained applications: it has a through-hole design, which enables direct mounting on the joint motor shaft. The RM08 encoder is a miniature high-speed rotary magnetic encoder: it has an 8 mm diameter and is IP68-rated for use in harsh environments. Both encoders feature low weight and volume to minimise inertias, a non-contact and frictionless design to eliminate mechanical wear, and high angular resolution and accuracy to ensure excellent servo performance. “We needed encoders that met our performance criteria without adding excess weight and volume, as any excess in the structure could be detrimental to the user’s mobility and might hamper the walking movement”, says Mr Plaza. We needed encoders that met our performance criteria without adding excess weight and volume. RESULTS RLS magnetic encoders have enabled Marsi Bionics to design and build exoskeleton orthopaedic devices that could improve the quality of life for people suffering from diseases such as SMA, multiple sclerosis and hemiplegia caused by stroke. Active exoskeletons will particularly impact the lives of young children, aged six and above, who are unable to move around by themselves. “It is of the utmost importance to achieve a stable movement and an exact position of each joint of the device. For that matter, the data collected from the encoders is fundamental for generating the position references. RLS and Renishaw provided us with the best encoder feedback solutions for our applications”, concludes Mr Plaza. For further information on Renishaw, visit www.renishaw.com. Issue 46 PECM 79