A Down-to-Earth Ergonomic Solution
The threat of repetitive stress injuries is present whether you’re working on an assembly line in Detroit or floating in outer space. That’s why General Motors and NASA have teamed up to develop a new type of glove that can help autoworkers and astronauts do their jobs better.
During last year’s Automate show in Chicago, I attended a keynote session that featured a GM engineer talking about how his organization was partnering with NASA on robotics projects. He promised that their collaborative efforts would soon result in new tools for use in production environments.
The Human Grasp Assist device (known internally in both organizations as the K-glove or Robo-Glove) is a good example of this R&D initiative, which started with the Robonaut 2 (R2) project—the human-like robot that was launched into space last year.
When GM and NASA engineers began collaborating on R2 five years ago, one of the design requirements was for the robot to operate tools designed for humans, alongside astronauts in outer space and factory workers back on Earth. The team achieved an unprecedented level of hand dexterity on R2 by using leading-edge sensors, actuators and tendons comparable to the nerves, muscles and tendons in a human hand.
Continuously gripping an assembly tool, such as a torque wrench, can cause fatigue in hand muscles within a few minutes. The Robo-Glove allows operators to hold a grip longer and more comfortably.
“When fully developed, the Robo-Glove has the potential to reduce the amount of force that an auto worker would need to exert when operating a tool for an extended time or with repetitive motions,” claims Dana Komin, manufacturing engineering director for global automation strategy and execution at General Motors. “In so doing, it is expected to reduce the risk of repetitive stress injury.”
For example, an assembler might need to use 15 to 20 pounds of force to hold a tool during a typical fastening operation. But, with the robotic glove, only 5 to 10 pounds of force might need to be applied.
Inspired by the finger actuation system of R2, actuators are embedded into the upper portion of the glove to provide grasping support to human fingers. “The pressure sensors, similar to the sensors that give R2 its sense of touch, are incorporated into the fingertips of the glove to detect when the user is grasping a tool,” says Komin. “When the user grasps a tool, the synthetic tendons automatically retract, pulling the fingers into a gripping position and holding them there until the sensor is released.”
The current prototypes weigh about two pounds and include the control electronics, actuators and a small display for programming and diagnostics. An off-the-shelf lithium-ion power tool battery with a belt-clip is used to power the system.
However, Komin says a third-generation prototype is nearing completion. It will use repackaged components to reduce the size and weight of the system. “Our goal is to bring this technology to the shop floor in the near future,” explains Komin.
Perhaps the Robo-Glove will go down in history with other space-proven technology that’s ended up being widely adapted back on Earth, such as Velcro and battery-powered screwdrivers.