Up until just a few years ago, the world of exoskeletons was dominated by large, heavy, multi-actuator, and complex exoskeletons. When someone talked about wearable robots, it was immediately understood that it will have a significant physical presence.
Rather than becoming larger, general exoskeleton development took a sharp turn in the opposite direction. The last two years have seen the popularization of passive exoskeletons, devices that have shed their motors (actuators) for springs and compressive elements that naturally store and release energy. Exosuits have kept their motors, batteries, and sensor packs, but have lost their hard metal frame. Quasi-passive / pseudo-passive devices still have power, but it is not used to drive the exoskeleton.
The winds of change may have turned in favor of smaller, lighter and simpler wearable devices but don’t count complex exoskeletons out just yet! Recently, two companies that specialize in exactly such wearable robotics have acquired a significant amount of funding:
- Wandercraft: € 15 million, Series B
- Sarcos: Awarded SBIR Phase II
Wander-who?
The Wandercraft is the most ambitious medical exoskeleton for individuals with complete lower body paralysis. Utilizing 12 powered actuators, this wearable robot easily qualifies as one of the most complex wearables being developed. The most ambitious part of the project, however, isn’t its hardware but its motion control software. The Wandercraft aims to have dynamic control, greatly reducing the amount of power consumption and producing a faster, more natural gait. If successful, Wandercraft will be the first exo of its type to feature dynamic control.
When people walk, we alternate between tensing up and relaxing our muscles. Human walking is similar to falling forward and catching ourselves. Current robotic devices have not quite mastered this trick, however, and their actuators remain active at all times. The REX, the closest exoskeleton in size and scope to the Wandercraft for example, will remain stable in any part of a step. While that is desirable from a safety point of view, this type of static walking is slower and can consume as much as 10 to 20 times more power. (For more on dynamic walking recall our coverage of SRI’s work, including the PROXI, Dec 2015)
Sarcos – We can lift it!
Sarcos® Robotics recently announced that it has been awarded SBIR Phase II contract with the U.S. military to develop a full-body exoskeleton for logistic applications. While most industrial exoskeletons are focused on enhancing the user’s safety or decreasing fatigue, Sarcos® Robotics believes that exoskeletons can be used to increase the maximum weight that a user can lift.
The Guardian™ XO® follows in the footsteps of the XOS and XOS 2, two of the most popular and well known by the general public exoskeletons from the early 2000s. Perhaps equally as ambitious as the Wandercraft, Sarcos® Robotics aims to augment and multiply the strength of the user. One potential application could be the fast loading and unloading of supplies in remote areas that are not accessible to forklifts or lack a paved surface altogether.
The successful funding for these complex exoskeletons proves that while the focus is shifting towards smaller wearables, the dream of making large powered suits is very much alive.
Sources:
Wandercraft raises € 15 million to let walking impaired persons walk again, Press Release, Sep 2017, http://www.wandercraft.eu/en/wandercraft-raises-euro15million/
Sarcos Robotics Awarded SBIR Phase II Contract to Develop a Full-Body Exoskeleton For Logistics Applications, Press Release, Nov 2017, https://www.sarcos.com/sarcos-robotics-awarded-sbir-phase-ii-contract-develop-full-body-exoskeleton-logistics-applications/
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