Control units are normally pre-programmed for specific tasks, though modern exoskeletons are increasingly becoming more adaptive. Some are equipped with algorithms that learn from users’ actual working behaviors to better support their actions.
However, assistance exoskeletons provide generally falls into three categories.
Power augmentation increases the force capabilities of the user. This is commonly seen in assistive exoskeletons, like those being used by IKEA and in Ukraine.
Assist-as-needed or resist-as-needed settings provide support to the body only when necessary. This setting is often used in rehabilitation devices, to help users train their bodies to recover lost capabilities.
Finally there’s full robotic control, where the exoskeleton assumes complete control over part of the body. This tends to be for users who have lost certain motor functions. For example, a lower-body exoskeleton might use full robotic control to allow someone with spinal cord injury to walk.
These ways of working can be combined and adapted according to the specific task, environment, and needs of the user.
What’s next?
For now, most exoskeletons rely on feedback from sensors to define how they exoskeletons behave; they’re wholly mechanical. But in the future exoskeletons could be operated with signals from the wearer’s muscles or brain. Research is exploring this, but it remains a challenge. Harnessing these signals might require an invasive interface and extensive user-specific calibration and adaptation.
Power is another current challenge. Batteries have to be integrated into exoskeletons and regularly recharged. This introduces weight and size constraints that affect practicality. The energy density of batteries is steadily improving, however.
New materials are also pushing the boundaries of what’s possible. Exoskeletons are being developed that are made from soft textile or rubber-like materials that can be integrated into clothing, footwear, or protective equipment.
Research into walking exoskeletons during the 1960s and 1970s contributed to the development of the first humanoid bipedal robots. This has come full circle. Interest in humanoid robotics is now accelerating the development of actuators and batteries. These will advance the wearable robotic technologies of tomorrow.
Ildar Farkhatdinov, Senior Lecturer in Healthcare Engineering (Robotics and Mechatronics), King’s College London. This article is republished from The Conversation under a Creative Commons license. Read the original article.