This article is the conclusion of Exoskeletons in manufacturing: Part 1.

Augmenting abilities

While passive exoskeletons provide lift and holding assistance to reduce fatigue, wearable robots could provide an even greater augmentation of human abilities such as supernumerary limbs, navigation and guidance.

Engineering researchers at MIT’s d’Arbeloff Laboratory are developing supernumerary robotic limbs (SRLs), akin to those used by Doctor Octopus in “Spiderman.” In “Supernumerary Robotic Limbs for Human Augmentation in Overhead Assembly Tasks,” the researchers describe how wearable supernumerary robotic limbs or arms could provide abilities to pass tools or firmly hold work pieces while the human hands perform assembly tasks. “The wearable robot, a Supernumerary Robotic Limb (SRL), can lift an object and hold it while the wearer is securing the object using a tool with both hands,” the researchers said. “The worker does not have to take a laborious posture for a long time, reducing fatigue and injuries. Furthermore, a single worker can execute the task, which would otherwise require two workers.”

Figure 1: An electrically powered exoskeleton developed by Tsukuba University of Japan. Source: Steve Jurvetson/CC BY 2.0With a pair of SRLs a welder could precisely and steadily hold heavy components, even in overhead or awkward positions during difficult joining tasks.

While robots were formerly restricted to cages to protect workers, emerging collaborative robots have sensors to stop movement and avoid harming a human. Wearable robots will likely have collision avoidance sensors and control systems to protect wearers and their co-workers. As the exoskeleton industry matures, specialized wearable robots with additional sensors and enhanced capabilities for specific tasks could emerge. Perhaps a future wearable robot specialized for welding will have integral sensors capable of monitoring current, voltage, stand-off distance, joint spacing, weld pool temperature or heat affected zone (HAZ) temperature, or even spectrometers to detect oxidation or compositional changes. Feedback could be used to control and optimize weld joint quality. Collaborative wearable robots or exoskeletons will leverage the best attributes of human and machine or robot to optimize the completion of joining tasks.

Expanding the workforce
Exoskeletons provide several additional benefits to employees. Wearable robots and related assistive technologies have the potential to offer more opportunities to individuals who may not have been considered for manual labor tasks previously, such as disabled persons. Young workers are often less interested in physically demanding jobs like welding and grinding, but exoskeletons could make welding and similar tasks more attractive to a larger group of people.

Additionally, manipulating large workpieces or welding torches would not be an issue. Women and smaller men could perform welding jobs requiring heavy lifting. Active exoskeletons or wearable robots could eliminate almost all of the physical stress for a period of time, preventing injuries.

Safety, testing and standards development
Exoskeletons enhance the safety and well-being of workers in some respects, such as reducing musculoskeletal injuries. Wearable robots with integral accelerometers and collision sensors might prevent workers from bumping into objects, prevent falls or reduce impacts during falls or collisions.

The long-term safety and ergonomics of exoskeletons is still not well-understood. Exoskeletons have entered the market, but tests and standards must be developed to evaluate their performance, ergonomics, healthcare impact and long-term safety, according to the “Test Methods for Exoskeletons – Lessons Learned from Industrial and Response Robotics” chapter in “Wearable Exoskeleton Systems: Design, Control and Applications.”

Without standards and test methods, purchasers and end users will have difficulty in making head-to-head comparisons of exoskeletons from different manufacturers. Several safety questions arise that need to be answered. Can these devices overdrive joints and muscles? Will poorly fitting exoskeletons cause skin chafing and wearer strain? If a wearable robot removes too much of the load on a worker’s muscles, will they atrophy over time?

Conclusion

Ford, Caterpillar, BMW, Boeing, Toyota, General Electric and other manufacturers are evaluating and implementing exoskeletons in their factories to enhance worker strength, endurance, safety, well-being and productivity. While passive exoskeletons are deploying today, future wearable robots on the horizon will provide a high degree of human augmentation, which will enable unbelievable new abilities and assembly methods.