Robo-Glove to assist astronauts on future space missions
NASA and General Motors have teamed up to create a robotic glove which increases the strength of the human grip.
The glove is officially known as the Human Grasp Assist device, but it is more commonly referred to as the K-Glove or Robo-Glove.
The glove has been designed to assist astronauts and auto workers in certain tasks. Continuously gripping a tool can cause muscle fatigue in the human hand within a few minutes, as well as potentially causing more long term repetitive stress injuries. Robo-Glove allows the wearer to grip a tool for a longer period of time than normal, as it reduces the amount of force that the wearer needs and thus also makes the doing the job more comfortable.
The actuators embedded within the glove are what provide the grasping support. Pressure sensors in the glove can detect when a person is holding a tool, and then cause the synthetic tendons retract to activate the gripping manoeuvre. When the sensor is released, the grip is then relaxed. Robo-Glove is also coated in a “skin,” which was created by Oceaneering Space Systems, and the glove is powered by an off-the-shelf lithium-ion battery.
The first Robo-Glove prototype has just been completed, with a second prototype due to be finished in three months time.
The current Robo-Glove weighs around a kilogram, but future designs should reduce the weight and the overall size of the system to make it more convenient.
It is hoped that Robo-Glove can be incorporated into spacesuits, so that astronauts could avail of it during extra-vehicular activity (EVA). However, this task is not as simple as it may seem.
“We're still investigating how it could be implemented into spacesuits,” explains Lyndon Bridgwater, lead mechanical engineer for Robonaut 2 and the Robo-Glove. “There are a number of ways it could be done, and some are easier than others. But the easiest ones are not necessarily the most useful. This is a new technology, and we've got a lot to learn about it.”
The Robo-Glove design is based on a human-like robot called Robonaut. Work began on the first Robonaut, R1, in 1997. This was a prototype that remained Earth-bound, and work stopped on the robot in 2006. However, General Motors became interested in robot development and an agreement was struck between them and NASA in 2007 to construct Robonaut 2, or R2.
The aim was to create a human-like robot that would be able to use tools in the same manner as we do. Thus it would function in the same workspace as humans, and wouldn’t need electronic connections to operate tools.
Robonaut 2 was launched via the Space Shuttle Discovery on 24 February 2011, and it now resides on the International Space Station, making it the first humanoid robot in space. It currently consists of an upper body and it will be upgraded to include legs for manoeuvring through the ISS. R2 can handle a wide variety of tools which could be used in an EVA. It is also much faster and more dextrous than R1.
R2 has sensors, actuators and tendons which can be compared to the human nerves, muscles and tendons, which is what inspired the Robo-Glove design. The hand on R2 was vastly improved over R1, due to improvements made on the thumb design which is the same scale as a human thumb and can thus grasp better.
Robo-Glove alongside Robonaut 2. Credit: NASA
It is expected that Robonaut will lead to further “spin off” technology, such as an arm which could be used on NASA’s Multi-Mission Space Exploration Vehicle (MMSEV). Proposed in 2011, MMSEV will be able to transport crews over long distances in space.
Bridgwater told Sen how a Robonaut-based arm could be incorporated with the MMSEV to assist in an asteroid exploration mission. “The MMSEV will actually have several arms on it - some, for instance, to basically anchor the vehicle on an asteroid and hold the it at a safe distance. The ones similar to the Robonaut arm would be smaller and used to pick small objects on the asteroids up or place objects or equipment onto the surface an asteroid.”
Robonauts are essential to future space exploration. Not only could they act as scouts on precursor missions, but they could also perform tasks such as servicing satellites.
The Robonaut technology is also being combined with a rover design, in a four-wheeled platform known as Centaur. Eventually, these could be used for lunar and Martian exploration.