Humans and Robots pdf - NASA

1 National Aeronautics andSpace AdministrationEducational ProductEducators Grades 5-12EB-2001-04-004-JSCE ducational BriefHumans and RobotsFollowing the remarkable successes of the ApolloMoon landings and the Skylab space station program,many space experts began reconsidering the role ofhumans in space exploration. In a healthy debate onexploration strategies, some experts concluded the goalsof the future would be best served by robotic space travelers require extensive life supportsystems. With current propulsive technologies, it wouldjust take too long to reach any destination beyond theMoon. Robots could survive long space voyages andaccomplish exploration goals just as well as space experts disagreed. Humans have animportant place in space exploration, they and Humans are not interchangeable.

2 Humansare far more adaptable than Robots and can react better tothe unexpected. When things go wrong, Humans canmake repairs. This, they pointed out, was demonstratedconclusively during Skylab, when spacewalkers maderepairs that saved the , new exploration strategies are at work. Thegoal is no longer Humans or Robots . It is Humans androbots working together. Each bring importantcomplimentary capabilities to the exploration of has been demonstrated time and again with theSpace Shuttle Remote Manipulator System (RMS) robotarm. The arm, also called Canadarm because it wasdesigned and constructed by Canada, has beeninstrumental to the success of numerous space 15-meter-long arm is mounted near the forward endof the port side of the orbiter s payload bay. It has sevendegrees of freedom (DOF).

3 In robot terms, this meansthat the arm can bend and rotate in seven differentdirections to accomplish its tasks. Like a human arm, ithas a shoulder joint that can move in two directions (2 DOF); an elbow joint (1 DOF); a wrist joint that can roll,pitch, and yaw (3 DOF); and a gripping device (1 DOF).The gripping device is called an end effector. Thatmeans it is located at the end of the arm and it has aneffect (such as grasping) on objects within its reach. TheRMS s end effector is a snare device that closes aroundspecial posts, called grapple fixtures. The grapplefixtures are attached to the objects the RMS is trying several occasions, the RMS was used to graspthe Hubble Space Telescope and bring the spacecraft intothe orbiter s payload bay. After the spacecraft waslocked into position, the RMS helped spacewalkingastronauts repair the telescope and replace some of itsinstruments.

4 During operations, the RMS is controlledby an astronaut inside the orbiter. The RMS actuallybecomes an extension of the operator s own cameras spaced along the RMS permit theoperator to see what the arm is doing and precisely targetits end effector. At times, during the Hubble servicing,one of the spacewalkers hitched a ride on the endeffector to gain access to parts of the telescope that weredifficult to reach. The arm became a space version ofthe terrestrial cherry (MT)Mobile RemoteServicer BaseSystem (MSB)Special PurposeDexterous Manipulator(SPDM)Space StationRemote ManipulatorSystem (SSRMS)Truss BeamInternational Space StationMobile Servicing System(MSS) Humans and Robots2EB-2001-04-004-JSCR obots on the International Space StationThe International Space Station (ISS), currentlyunder construction in Earth orbit, will have severalrobots to help astronauts complete their tasks in of the ISS international partner nations aredeveloping robotic systems for the station.

5 Japan isdeveloping the JEM Remote Manipulator System. TheEuropean Space Agency and the Russian Space Agencyare developing the European Robotic Arm. Canada andthe United States are developing the Mobile ServicingSystem (MSS). Detailed information on each of thesesystems can be obtained at the website listed Servicing SystemThe most complex robotic system on the ISS is theMSS. It consists of the Space Station RemoteManipulator System (SSRMS), the Mobile RemoteServicer Base System (MBS), the Special PurposeDexterous Manipulator (SPDM), and the MobileTransporter (MT). The MSS will be controlled by anastronaut working at one of two Robotics Work Stationsinside the primary functions of the MSS robotic system onthe ISS are to: assist in the assembly of the main elements of thestation ( aligning newly delivered modules to thestructure) handle large payloads replace orbital replacement units (plug-in equipmentdesigned to be periodically replaced with newer units) support astronauts during extravehicular activities assist in station maintenance provide transportation around the stationThe main component of the MSS is the 17-meter-long SSRMS robot arm.

6 It is similar to the Shuttle RMSbut will ride from one end of the station to the other onthe mobile transporter, which will glide along the gianttruss beam. After arriving at a worksite, the arm willgrasp payloads, modules, or other structures with its wiresnare end effector. If a work location is too distant forthe arm to reach while still attached to the transporter,the arm can connect to an intermediate grapple power will be rerouted through that SSRMS will then release its other end and inchworm itself through successive fixtures until itreaches the desired site. The SSRMS is also able to pickup and connect to the SPDM. This unit consists of a pairof , 7-joint arms connected to a single jointbase. The SPDM can pick up small tools for repair orservicing activities or effect delicate manipulations ofsmaller objects than the SSRMS can EndEffector "B Camera, Light AssemblyJoint Electronics UnitB End IndicatorStripeWrist Joint(roll, pitch, yaw)Camera Light,Pan/Tilt UnitBackup DriveArm ComputerUnitLatching EndEffector "A"Camera Light,Pan/Tilt UnitElbow(pitch)Space Station RemoteManipulator SystemGrapple FixtureInterfaceElectronic UnitsArm InterfaceLatch/UmbilicalMechanism (4)Latching End EffectorPower and DataGrapple FixtureHumans and Robots3EB-2001-04-004-JSCL atching EndEffectorBody JointElectronic UnitToolHolsters (4)JointElectronicsUnitPower/DataGrapple FixtureORU/Tool ChangeOut MechanismForce MomentSensorWrist Joints (3)(roll, pitch, yaw)Elbow Joint(pitch)

7 Shoulder Joints (3)(roll, pitch, yaw)Arm ComputerUnit (2)Camera, Light andPan/Tilt Unit (2)Body JointSpecial PurposeDexterous ManipulatorRobotic WorkStationThe FutureAdvanced robotic systemsare under development for useon the ISS. The ISS providesan exceptional laboratoryfor testing newrobots such asNASA will feature endeffectors based on the human hand andwill be capable of handling detailed andcomplex tasks. It will interface with the MSS and serveas a spacewalker s assistant or surrogate for tasks toodangerous for astronauts return to Earth s Moon and set footon Mars, they will not be alone. Robots will be there asassistants and partners in the exploration of research and application on the ISS will lead theway for the advanced intelligent robotic systems of Activity Making and Using an ISS End EffectorMaterials and ToolsStyrofoam coffee cups (2 each)String - 12-cm pieces (3 each)Cellophane tapePlastic picnic knives (serrated)Objectives: Students will learn how the end effectors for therobotic arms used on the Space Shuttle and theInternational Space Station work.

8 Students will design and construct a grapple fixture thatwill enable the end effector to pick up an Standards:Science Content Abilities of technological designTechnology Education Content8. Students will develop an understanding of theattributes of design9. Students will develop an understanding of engineer-ing design10. Students will develop an understanding of the role oftroubleshooting, research and development, inven-tion and innovation, and experimentation in problemsolving11. Students will develop abilities to apply the designprocessTeaching Plan:In this activity, students can worksingly or in small groups of two orthree. Have students use a sawingmotion to cut through the cups. It iseasier to cut through the outer cupfirst and then the inner part about cuttingthe two cups is that theircut-off ends lie flushwith each other whenthe cups are the knives as scrapersto smooth the cut completing the endeffector, have your students design agrapple fixture.

9 The idea here is todesign something that the end effector can grab ontowithout slipping off. After grapple fixtures arecompleted, tell students to compare their fixture to thosecreated by two other students or groups. Ask them tocreate a table or a chart comparing the strong and weakpoints of the fixtures they evaluated. They shouldsummarize theirresults with astatement abouthow they canimprove thefixture : For more information about Robots on the International Space Station,refer to the reference section of this web site. and Robots4EB-2001-04-004-JSCM aking the End Effector:1. Nest the two cups together and cut through both cupswhere indicated in the diagram by the dashed the cut edges by scraping them with thepicnic knife Cut three pieces of string 12 centimeters long Tape the end of the first string to the inside of theinner coffee cup just below the cut edge.

10 Tape theother end of the string to the outside of the cup but donot press this piece of tape tightly Repeat step 3 twice more, but place the strings about1/3 of the way (120 degrees) around the cup from thefirst While holding the rim of the inner cup, rotate theouter cup until the three strings cross each other. Thestrings will have some slack. Pull the end of thestrings on the outside until they are straight andintersect exactly in the middle of the opening. Pressthe tape on the outside to hold the the End Effector:1. Use the end effector to pick up an object such as apencil. Have someone hold a pencil upright. Openyour end effector so that the strings are not crossingeach other. Slip the end effector over the pencil sothat the pencil extends down the center and notthrough any of the loops.