MFD (Manipulator Flight Demonstration) Crew Training System

3DSHU ,' DMFD (Manipulator Flight Demonstration)Crew Training SystemMasanori NAGATOMO 1) , Chikara HARADA 1) , Kenji MORISHITA 1)Masahiro AIURA 2) , Masayuki IKEUCHI 2) , *Yasushi TAKADA 2)1) National Space Development Agency of Japan(NASDA)Sengen 2-1-1, Tsukuba, Ibaraki, 305-8505, JapanFAX:+81-298-54-3933E-mail: Nagatomo.Masanori@nasda.go.jpHarada.Chikara@nasda.go.jpMorishita.Kenji@nasda.go.jp2) Toshiba corporationToshiba-cho 1, Komukai, Saiwai-ku, Kawasaki, 210-8581, JapanFAX:+81-44-548-5075E-mail: aiura@uchu.komukai.toshiba.co.jpike@uchu.komukai.toshiba.co.jptakada@uchu.komukai.toshiba.co.jpABSTRACTThis paper presents the MFD (Manipulator Flight Demonstration) crew training system, which is composed of twosubsystems, that is, MFD Trainer and MFD Simulator. MFD was launched on August 7th, 1997 by NASA spaceshuttle STS-85 to evaluate the function and performance of JEM (Japanese Experiment Module) SFA (Small FineArm) in space. The mission of MFD was the demonstration of tasks to replace ORU (Orbital Replacement Unit), toopen/close a door and so on. The crew training system was used for the crew training of flight operation. MFDTrainer is equipped with a robot arm which can be operated under 1-G gravity. It was mainly used for the operationtraining accompanied with hardware contact between the arm and other MFD elements. The training which usedMFD Trainer was held on 9 months before launch and on 4 months before launch at NASDA Tsukuba SpaceCenter.MFD Simulator expresses movement of MFD elements in space by using computer graphics technique (kinematics)while a shuttle crew operates the hand controllers, and it has the equipments which simulate the equipments in aftflightdeck of the space shuttle. MFD Simulator can simulate some malfunctions according with the factors set bytraining instructor.MFD Simulator was placed at NASA JSC(Johnson Space Center) and it was mainly used for NASA crew tomaster the nominal operation procedure and how to deal with malfunctional situation.MFD Simulator was also utilized to conduct JIS (Joint Integrated Simulation) with NASA POCC(PayloadOperation Center) at JSC.JIS was the total rehearsal training in which NASA POCC, NASA crew and MFD POCC took part. It simulatedthe actual operation of MFD.After landing of STS-85, the MFD Simulator was evaluated that MFD Simulator had been effective to masteroperation procedure of MFD and MFD Trainer had been especially effective to control the robot arm by using handcontrollers. In the evaluation, it was also said that it was necessary to simulate the force/torque for the training ofrobot operation like MFD, (MFD Simulator does not simulate the force/torque because it simulates the robot arm byusing kinematics model), and to simulate all malfunction operation.Future robot arm training system will include the above crew comments for MFD training system.

3DSHU ,' D1. IntroductionMFD (Manipulator Flight Demonstration) project is to demonstrate the functions and performances of therobot arm similar to SFA (Small Fine Arm) of JEM (Japanese Experiment Module) in the weightlessspace environment using the space shuttle prior to a JEM launch, and to reflect those results andexperience to the JEM development and operations.MFD shuttle loading system was launched on the space shuttle “DISCOVERY”, STS-85, from KSC onAugust 7 th , 1997 and landed to KSC on August 19 th , 1997.Figure 1-1 Japanese Experiment Module (JEM)Various missions ready for MFD were conducted in the above term and all the MFD robot armoperations were successfully conducted.The shuttle loading system of MFD consists of PLB (Payload-Bay) elements and AFD (Aft Flight Deck)elements.PLB elements consist of a robot arm which has 6 joints, a tool which has fingers and a torque driver, aORU which the arm will capture/release and attach/detach for a mount plate, a hinged door which thearm will open/close, and some cameras/lights.Also, MFD has the piggyback experimental equipment such as TPFLEX (Two-Phase Fluid LoopExperiment) and ESEM (Evaluation of Space Environment and Effects on Materials).AFD elements are in the aft flight deck of the shuttle and consist of the equipment necessary to control therobot arm such as hand controller which the crew will use to control the arm manually, PGSC (PayloadGeneral Support Computer) which is to confirm the telemetry information of MFD, two CCTV(ClosedCircuit Television) monitors which show the camera view at the PLB and so on.The crew can continue the MFD operation by means of the process below:the crew changes the position and posture of the tip of the robot arm, confirms the telemetry from PGSC,and checks the condition of the payload bay elements with the two CCTV monitors.The operation of MFD is mostly to control the robot arm under program control mode, manual controlmode, and single joint control mode.

3DSHU ,' DMFD is in holding position in the initial condition for the safety reason. In the start of an experiment ofMFD, the robot arm is deployed first. Once the arm is set in the neutral position, various experimentsare able to execute. In the end, the arm is in holding position again.The MFD experiments are to check the performance of the arm under the program control, tocapture/release the ORU, to attach/detach the ORU for the mount plate under the manual control, to openand to close the door, and so on.When the arm captures the ORU/ the door, or when the arm attaches the ORU on the mount plate, thecompliance control function of the robot arm works.Consequently, the confirmation of the efficiency of the function is also an important mission of MFD.2. MFD crew training system2.1 The purposeThe main purpose of MFD crew training is one; to learn the procedure on the onboard before a MFDlaunch, two; to learn how to operate the equipments like hand-controller.2.2 The constructionWe developed MFD Simulator, which could imitate PLB elements by CG, for the reason below:MFD payload had to satisfy the safety requirements to be loaded in the space shuttle. It also neededenough training term according to the complicated procedure for any malfunction. To simulate themalfunctions such as the reckless movement of the arm is not only dangerous for the members joined inthe training but also the training system might hurt itself.The size and the function of the SRMS(Shuttle Remote Manipulator System) are fairly different fromMFD robot arm even though they both can be controlled by the hand-controller. Especially thecompliance control function had not put in the robot arm for space before, accordingly, it was totally anew concept for the crew. The compliance control function manages the force/torque in the tip of thearm. The crew has to learn that the movement of the robot arm under the working of the function isdifferent from using the hand-controller because it works differently under the task with the physicalcontact such as capturing the tool fixture, attaching/detaching ORU, or opening/closing the door.Because this was not easy to simulate with numerical value, we needed to develop the MFD Trainer thatcould actually simulate the physical contact.2.3 MFD SimulatorMFD Simulator consists of the training department in which the training instructor controls the training(the instructor workstation, the two graphics generators, the arm control computer) and the department inwhich the crew works during the training (the panels such as ESP, PGSC and CCTV monitors). Theinstructor workstation, the graphic generators and arm control computer are connected with LAN. Italso has the interface of LAN and video to the MFD ground system, which is called “POCC EGSE”, asthe interface to the outside.The basic job of MFD Simulator is as follows:The training begins after the instructor workstation sets up to the initial stage of the training, and the armis commanded by the crew operations in accordance with the operation procedures. The arm controlcomputer then calculates the angle of the joints and other things based on this order to the arm. Using theinformation of the joint angles and the camera selection, the graphics generator draws the PLB elementswith CG. It shows on CCTV monitors.And the instructor workstation sends various informations to PGSC, and PGSC shows it.

3DSHU ,' DCrew can continue the operations by watching the state of payload-bay with CCTV monitors and byconfirming the telemetry with PGSC as a numerical value.%30 ##46 MONITORS0'3#!RM CONTROL COMPUTER)NSTRUCTOR WORKSTATION'RAPHICS GENERATORSFigure 2.3-1 MFD SimulatorMFD Simulator imitates in high fidelity the AFD elements which the crew touches directly or look at andwhich are necessary for MFD employment.This CG is based on the model for vision analysis of MFD shuttle loading system. Also, it reduces itsgraphic data enough to move the robot arm in real-time.The movement of the robot arm by CG is calculated by using kinematics model because it is difficult forthe arm control computer to calculate the dynamics model.So, MFD Simulator does not simulate the force and torque loading on the robot arm.The instructor workstation has the functions written below:1. A function which sets the initial stage of trainingWith a little limitation, we can snapshot certain moment during training, and can apply that as thesetting up initial stage.With this function, we do not have to start the training from the condition which the robot arm isholding position, consequently, we can save time as a result.2. A function which sets the telemetry needed for the trainingWe can set not only the joint angles, micro-switch information and so on, which change accordingto the crew’s operation, but also the temperature and voltage, by registering on the database, as thetelemetry.

3DSHU ,' D3. A function which grasps all the information needed for training such as the results of panel switchoperations by crew, the display of PGSC, the value of each simulated telemetry and presents them tothe instructor.4. A function which replaces the value of the telemetry or sets/cancels the malfunctionWe can set the malfunction by blackout of the picture of the camera for example, even thoughthere is no change of the value of the telemetry or no telemetry at all such as fixing the angle of thejoint or lowering the temperature.NASA has been taking the initiative of the training about the payload of the shuttle, so that MFDSimulator was established in building #5, JSC in January 1997 and the crew training by the NASAinstructor took place for about 7 months till the launch.2.4 MFD TrainerMFD Trainer is based on the robot arm for the operating evaluation system of JEM SFA to support thetraining sense about dynamics of a robot arm which MFD Simulator does not simulate. (Refer figure 2.4-1)It has hardware of the robot arm which supposed to work under 1-G, ORU, mount plate and door.Because the ORU is balanced in gravity by using the 0-G counter balancer, the arm can detach the ORUfrom the mount plate.Figure 2.4-1 MFD TrainerMFD Trainer is mainly for crew to understand the compliance function.MFD Trainer is settled in Tsukuba Space Center and NASA instructor and crew came to Japan in 9months and 4 months prior to the launch and spent several days for training.Besides the nominal training, we simulated malfunction with MFD Trainer 4 months prior to the launch.We have proved that, by repeating subtle single joint movement, it is possible to pull out the tool from thetool fixture of ORU/door and to pull out ORU with the arm capturing it from the mount plate, thus thishas been added as a new off-nominal procedure.3. Usage other than crew trainingAt JIS (Joint Integrated Simulation)

3DSHU ,' DMFD, the payload of the space shuttle, rehearse with the crew who operates MFD, the grand control teamof MFD, and the grand control team of the shuttle altogether, as training.At this time, MFD Simulator actually simulated the MFD loading system and the crew operated.Then, MFD Simulator generated the graphic of payload bay and imitated telemetry from MFD loadingsystem and sent them to MFD grand control system via the grand control system of the shuttle.With this work, we could train the grand control team based on the telemetry and videos, which aresimulated on real-time with the result of the crew’s operation.4ELEMETRY $ATA6IDEO $ATA-&$ 3IMULATOR4ELEMETRY $ATA6IDEO $ATA6OICE $ATA/FFLINE $ATA343-&$.!3!'ROUND3YSTEM0/## %'3%4ELEMETRY $ATA#OMMAND $ATA'ROUND #OMMANDINGFigure 3-1 JIS (Joint Integrated Simulation Diagram)At actual operationWhen a malfunction occurs onboard in actual operation of MFD, MFD Simulator reproduces it onground and is used to analyze the malfunction.MFD Simulator also has the function which complements videos in actual operation of MFD other thanthe original training function.The reason for this function is that the crew can choose the onboard camera whose vision is down-link tothe ground in its actual operation from only one camera out of 2 fixed cameras of MFD itself, 2 balk-headcameras of the shuttle, or MFD’s arm camera,So, the ground control team cannot get the videos which are displayed in two CCTV monitors.Consequently, MFD Simulator could get the telemetry of the shuttle in its actual operation from theground control system, generate the graphics of the arm’s position/posture onboard, then give the graphicsback to the ground control system.Moreover, we can see the important viewpoint from any angle besides those 5 cameras for MFDoperation.By using this function, we could support the ground control team by, for example, checking whether thearm has collided with the other elements where the cameras cannot see well.-&$ 3IMULATOR4,-4ELEMETRY $ATA343-&$6IDEO6OICE.!3!'ROUND3YSTEM4ELEMETRY $ATA6IDEO $ATA6OICE $ATA/FFLINE $ATA#OMMAND $ATA0/## %'3%4ELEMETRY $ATA'ROUND #OMMANDINGFigure 3-2 Actual Operation Diagram

3DSHU ,' D4. The evaluation of MFD crew training systemWe evaluated the crew training system after actual operation of MFD.Crew had the chance to operate and evaluate MFD Simulator right after STS-85 returned to the earth andMFD Trainer in November.The crew’s comments for the MFD Simulator and MFD Trainer are below:• MFD Simulator was effective to train crew to learn the procedure of MFD operation.• MFD Simulator was effective in training operation as pair.• MFD Simulator did not simulate the compliance control function.• The access to the tool-fixture was too easy in simulator.• MFD Trainer was effective to train crew to learn the procedures that the arm capture the toolfixtureand attach ORU to mount-plate.Because we did not simulate the dynamics, we had to rely on MFD Trainers to understand thecompliance and because we did not simulate the compliance, the access to the tool-fixture became so easy.Therefore, the calculations of dynamics should be introduced for CG simulation.However, MFD Simulator would be enough for learning only the procedure of MFD.In contrast, MFD Trainer is highly evaluated because it simulates the compliance as the first purpose.As a result, we should have brought MFD Trainer to NASA, or have increased the opportunity oftraining in Japan by using the MFD Trainer.5. ConclusionMFD mission was a success throughout the whole operation. Also, MFD crew training systemcompleted the initial purpose and contributed to MFD mission.And, We are thinking to improve the training system of JEM and future robot arm, such as:• The logic-flow, logically the training system can output as much the same as the flight system.• The latency; the training system had better simulate the response time needed forswitch.operated by crew.• The room, the training system should remain a little room which the flight system has.• The view, the training system should have the outside view of the window such as AFDwindows of a space shuttle or JEM.• The CG, the training system should reduce the difference of the CG picture from the flightsystem as much as possible.6. Reference(1) Documents of MFD Symposium NASDA in March, 1998