30 ElEctronics Robotics Engineering & technology 13 November - 10 December 2010 www.theiet.org/magazine
31Semi-autonomous robots are on duty throughout the solarsystem – prosaic little boxes, waiting patiently to act out thelatest transmission from Earth. However, one passengeraboard Nasa’s STS-133 mission to the Destiny laboratoryon the International Space Station may just ignite thepopular imagination. By Piers Bizony.robonaut it may seem like some sort of science-fiction scenario, but clever robots are scattered widely across the vastness of our solar system. all deep-spaceflies in probes and planetary landers are capable of operating semi- autonomously in order to cope with the long time-lags between radio commands from earth. some, such as Nasa’s wheeled mars rovers, also boast certain degrees of mechanical flexibility provided via pan-and- tilt camera arrays, directable radio antennas, steerable wheels, extendable soil-sampling arms and other instruments. the public perhaps struggles with the idea that these clunky boxes are definable as robots, but no one will be in any doubt about Nasa’s latest non-human space explorer. at first glance it looks just like an astronaut in a space suit. even at second glance, it seems at least as lively as a ‘star Wars’ character in an armoured mask. its head is shaped somewhat like a motorcycle helmet, but its torso and arms, tipped by elegant hands with slender fingers and opposable thumbs, look very like our own. Robonaut, the first humanoid robot ever sent into space, has just arrived at the international space station aboard space shuttle Discovery, as part of the payload for the sts-133 mission. it was stowed for launch inside the european-built Leonardo cargo supply module, which is now docked permanently on the station to provide yet more pressurised working volume. in the coming months, the robot will be unpacked from its crate and repositioned inside the larger Destiny laboratory module. although its primary task, for now, is to remain aboard the station while under- going further tests, it will eventually be deployed outside the pressurised shell of the orbiting platform, where it will assist human space walkers in assembly and maintenance tasks. this flightworthy version of the hardware is a second-genera- tion machine, based on a proto- type developed by Nasa and the E www.theiet.org/magazine 13 November - 10 December 2010 Engineering & Technology
33 ‘Here’s a robot that can Robonaut joined mission sts133 see the objects it’s going after, feel the environment and adjust to circumstances. That’s pretty human. It opens up endless possibilities.’ Ron Diftler, Nasaneatly into the top of a single writer Isaac Asimov some half a operator inside the spaceleg, with hip, knee and ankle century ago. In simple terms, an station, or down on the ground. one small stepjoints. The ‘foot’ is an adaptor Asimovian robot has freedom of A stereo vision helmet alliedthat clicks into various attach-ment points on the outside of the action unless the proposed action threatens to cause harm to a force feedback endoskeleton and a pair of gloves studded luNar roboNauTspace station, or on the end of to a human. with haptic sensors enables the In November last year, a studylong and similarly articulated Similarly, Robonaut operates operator to see and even to feel group at Nasa’s Johnson Spacerobotic boom arms that are a hierarchy of ‘sub-autonomies’, Robonaut’s environment. The Center wrote the brief for Projectalready part of the station’s with harm avoidance at the system is an advanced form of M, a proposed mission to land aexternal equipment. Swapping top of the pyramid. Various what’s known as ‘telepresence’. Robonaut on the Moon in 1,000between available handholds sub-autonomies run motion The application programmer’s days flat, measured from the timeand leg attach points, Robonaut control in 3D Cartesian space, interface (API) allows more than of budgetary approval to thewill clamber from one secure the vision system, the teleoper- 40 degrees of freedom to be moment of touchdown – M beinglocation to the next, covering ator interface, joint control, controlled remotely in a ‘master- the Roman numeral for 1,000.ground, so to speak, as it makes and grasping actions. Each slave’ relationship where the The delivery vehicle would beits way from one end to the other sub-autonomy deals with its operator’s motions are a small single-engined landerof the sprawling complex, but own internal safety and decision mimicked, in near real-time, built by Armadillo Aerospace inwithout ever completely letting making, but will ‘request’ rather by the robot. Mesquite, Texas: one of a dozengo. It has no thruster packs or than ‘demand’ a reconfigura- A key factor in the API’s companies now making rapidindependent free-flying tion, or even a complete safety design is ease of use for the advances in the private rocketcapability. shutdown, if it senses trouble. human operator. Nasa likes to business. In June last year, Higher level software then design its control systems with Armadillo successfully tested aLaws of Robonautics monitors potential conflicts the human-machine interface at prototype lander fuelled by liquidThe common industrial practice between the sub-autonomies and the forefront of its thinking. methane and liquid oxygen. Itof having a workplace robot compares them with safety Astronauts tend to have took off from its terrestrial launchcease all motion if anyone parameters before allowing or backgrounds in military platform, then hovered at a preas-inadvertently touches it is not disallowing certain tasks. aviation or aerospace signed altitude and finally,always appropriate for All this is accomplished by engineering, with biological performed a precision autono-Robonaut, because it must be PowerPC processors running and space sciences also adding mous landing.capable of interacting VxWorks, and wired to a Virtual to the selection mix. Relatively A lunar version of Robonautphysically with astronauts Machine Environment (VME) few of them are professionally would operate in near real-time,without necessarily coming to a backplane, or motherboard, familiar with computers or once the operators on Earth havestop every time one of them inside Robonaut’s torso. VME robotics. They need to operate acclimatised their working habitsbumps into it. In particular, it allows the sharing of the under- the Robonaut without having to around the one second or so ofhas to distinguish between lying machine resources know too much about its radio time lag in the commanddangerous collisions and between different virtual internal systems. Manipulation and feedback signals. Fancifuldesirable physical interactions machines, each running its own of the system must becomes as artwork shows the robotwhen tools are passed from operating system. intuitive as performing the walking on the moon on tworobot to human hands, or when The object-oriented machine’s tasks oneself. legs, but Ambrose thinks thatthe load of a particularly large ControlShell software frame- Could it be that Robonaut and bipedal locomotion may be toopiece of hardware is shared work is used to aid the overall his kind will one day supplant ambitious. “We’re looking atbetween the robot’s grip and development process, which will humans in space? John Olson, other lower body designs for thean astronaut’s. Ambrose says continue throughout Robonaut’s director of the Exploration Moon, with a four-wheel orthat indicator lights and other operational life. Systems Integration Office at six-wheel base,” he says. Neithercues will ensure that Nasa’s headquarters in can we expect any poeticRobonaut’s human minders the puppet masteR Washington, DC, says that such speeches when the robot takes itswill always have “a general Ron Diftler, Robonaut project a mournful outcome would be first look at the lunar terrain.understanding of what state manager at JSC, speaks proudly the very opposite of his agency’s Nasa’s Ron Diftler says, “It will bethe robot is in.” about these capabilities. intentions. “This project working alone a lot. It won’t really These states are analysed, “Here’s a robot that can see the exemplifies the fact that robots need to talk.”in part, with the help of force- objects it’s going after, feel the are not replacements for us, but In the light of the Obamafeedback sensors. But Robonaut surrounding environment and companions that can carry out administration’s cool attitudecan also see what it is doing. Its adjust to circumstances as key supporting roles alongside towards future lunar exploration,head contains four stereoscopic needed. That’s pretty us,” he says. Project M has not yet receivedcameras, one pair in standard human. It opens up endless The combined potential of serious funding. Even so, thedefinition and the other in HD. possibilities.” humans and robots is, Olson relative simplicity and low cost ofThis enables the machine to build On the evidence of such a believes, “a perfect example the mission could win it thea depth map of nearby objects, description, Robonaut sounds of the sum equalling more than necessary approval from USwhich assists in collision avoid- suspiciously smart. If its actions the parts. It will allow us to go lawmakers anxious about theance as well as in the perform- and intelligent behaviour seem farther and achieve more country’s technology sector.ance of its assembly tasks. almost spookily human, this is than we can probably even Young students in need of a little Robonaut’s hazard assess- because they really are human. imagine today.” L inspiration would be thrilled toment is loosely comparable to Despite its semi-autonomous become telepresent lunarthe famous ‘Laws of Robotics’ capabilities, it is essentially an L further information explorers.proposed by the science fiction avatar, driven by a human http://bit.ly/eandt-weblinks www.theiet.org/magazine 13 November - 10 December 2010 Engineering & Technology
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