NASA Robonaut

About Robonaut
Robonaut is a humanoid robot designed by the Robot Systems Technology Branch at NASA's Johnson Space Center in a collaborative effort with DARPA. The Robonaut project seeks to develop and demonstrate a robotic system that can function as an EVA astronaut equivalent. Robonaut jumps generations ahead by eliminating the robotic scars (e.g., special robotic grapples and targets) and specialized robotic tools of traditional on-orbit robotics. However, it still keeps the human operator in the control loop through its telepresence control system. Robonaut is designed to be used for "EVA" tasks, i.e., those which were not specifically designed for robots.

The goals is to build machines that can help humans work and explore in space. Working side by side with humans, or going where the risks are too great for people, machines like Robonaut will expand our ability for construction and discovery. Central to that effort is a capability we call dexterous manipulation, embodied by an ability to use ones hand to do work, and our challenge has been to build machines with dexterity that exceeds that of a suited astronaut. The resulting robotic system called Robonaut is the product of NASA and DARPA collaboration, supporting the hard work of many JSC Engineers that are determined to meet these goals.

Using a humanoid shape to meet NASA's increasing requirements for Extravehicular Activity (EVA, or spacewalks). Over the past five decades, space flight hardware has been designed for human servicing. Space walks are planned for most of the assembly missions for the International Space Station, and they are a key contingency for resolving on-orbit failures. Combined with our substantial investment in EVA tools, this accumulation of equipment requiring a humanoid shape and an assumed level of human performance presents a unique opportunity for a humanoid system.

While the depth and breadth of human performance is beyond the current state of the art in robotics, NASA targeted the reduced dexterity and performance of a suited astronaut as Robonaut's design goals, specifically using the work envelope, ranges of motion, strength and endurance capabilities of space walking humans. This website describes the design effort for the entire Robonaut system, including mechanisms, avionics, computational architecture and telepresence control.

The Hand

Robotic hands have been around for decades but they usually bear little more than a passing resemblance to the real thing. Now NASA researchers have raised the bar with a robotic hand that closely mimics the inner workings of the human hand.

The hand, part of the ongoing Robonaut project, is designed to use the tools and handholds astronauts use during space walks. This purpose, more than aesthetics, led the researchers to copy the human hand as closely as they did, said Chris S. Lovchik, an engineer at NASA's Johnson Space Center in Houston.

"The more you begin to look at tool use, [you find that different tools] involve different portions of the hand," he said. For example, the palm of the Robonaut hand had to be accurately modeled in order for the hand to grasp a screwdriver in alignment with the roll of the arm, he said.
The device is a right hand attached to a wrist and forearm. It has 12 controlled degrees of motion and 42 sensors for tracking the position and velocity of the hand' s moving parts. The researchers are adding tactile sensors.
"It's one of the best [robotic hands] that I've seen," said Reid Simmons, a senior research scientist at the Robotics Institute at Carnegie Mellon University. "It's really quite an amazing piece of work. It's got very good dexterity. It's amazing how compact it all is."

The Robonaut system, which will have a torso, two arms and a head, is designed to be controlled by a human operator. "The overall objective is essentially to create a surrogate for the astronauts," Lovchik said. Researchers are programming primitives, or sets of commands for simple actions, that make the hand easier for the operators to use. For instance, you don't think about how to draw a circle because your brain learned the primitives for drawing a circle in early childhood.
The researchers plan to automate simple tasks like grasping and could eventually make the hand fully automated, according to Lovchik. Fully automating the hand will be a major project, according to CMU's Simmons.
"A lot of what [humans] do very well is very fine force feedback control," Simmons said. "If you're putting and nut on a bolt you can feel when it's getting stuck and when it's too tight, and you can compensate for that. That type of [control] is beyond current state-of-the-art."

Robonaut could be ready for space missions in five years, according to Lovchik. Funding for the project comes from NASA and the Department of Energy.

Overall Design Description

Robonaut will have a humanoid design in order to mimic the movements of a real person

Robots aren't new to the space program. Robotic probes and rovers have been traveling to Mars since before man stepped foot on the moon. In 1965, the Mariner IV planetary probe sent back the first images of the red planet at close range. In 1997, the Pathfinder rover provided scientists with unprecedented detail of the Martian atmosphere and surface. What's different about the latest robotic astronaut is that it has a humanoid design with a head, two eyes, arms and five-digit hands. Let's take a look at the individual parts that make up the Robonaut:

Head -- Two small color video cameras are mounted in the head piece that delivers stereo vision to the astronaut operating the Robonaut. Stereolithography was used to make an epoxy-resin helmet to cover and protect the head piece. The neck is jointed to allow the head to turn side to side and up and down.

• Torso -- The torso provides a central unit for connecting the peripheral arm, head and leg attachments. It also houses the control system.
• Leg -- The one part of the Robonauts design that deviates from the humanoid look is that it has only one leg. The leg's only function is to provide support when the hands are unable to.
• Arms -- Just like its human counterparts, the Robonaut will have two arms that can move in many directions and have a greater range than our own arms. The arms will be equipped with more than 150 sensors each and will be densely packed with joints. Space-rated motors, harmonic drives and fail-safe brakes will be integrated into each arm.
• Hands -- Perhaps the most impressive parts of the Robonaut are its hands. Its hands are the closest to the size and ability of human hands inside a space suit. The jointed hand may even exceed the movements of a suited human hand. Fourteen brushless motors to power each hand are inside the eight-inch-long forearm. The hand has four fingers and an opposable thumb. The hand was designed with five digits so that it would be compatible with tools designed for humans. Researchers have demonstrated the Robonaut's ability to pick up a small metal washer with tweezers. Together, the arm and hand unit can lift 21 pounds (9.5 kg), which doesn't sound like much, but in a weightless environment it's plenty of strength.
  The Robonaut is an ongoing project at Johnson Space Center (JSC). NASA has spent about $3 million dollars and three years to develop this advanced space robot. However, Robonaut is unlikely to visit space in the next five years. Here are the current specifications for Robonaut:

  Specifications	Robonaut
  Height	6.23 ft. (1.9 m)
  Weight	410 lbs. (182 kg)
  Structural Materials	Mostly aluminum with Kevlar and Teflon padding to protect it from fire and debris.
  Computing Platform	PowerPC processor
  Operating System	VxWorks