1. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-24 Objectives Physical Configuration Mechanical Design Power Design Onboard computation Control Software Sensing Testing Resources Covered so far Still to be covered OverviewOverview

2. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-25 Onboard Hardware Selection Issues Processing horsepower to perform sensor analysis Ease of interfacing with motion controllers and sensor feedback Form factor –Intention is to have it fit in the 4”Ø tubes Extensibility Features –i.e. Ethernet, IDE, video Power consumption OS support

3. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-26 Controls Issues Multi-robot planner will have a good but imperfect model of robot positions and environment In manipulator mode Skyworker becomes a chain manipulator with redundant DOF’s While walking the payload needs to be moved at a constant velocity to minimize energy consumption and torques Three types of actions –Walking without payload –Walking with payload –Manipulating from a fixed point

4. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-27 Control Layers

5. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-28 Software Design Issues Correct errors associated with inexact modeling of world and robot Modularity –Easy interchange and upgrade of component elements –Objectified components allows melding of simulation and real world Control partitioning and scalability concerns Provide the user with a common simulation and operation interface

6. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-29 Software Blueprint

7. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-30 What Will Simulation Provide? Emulation of Skyworker An identical interface as used to talk to the real robot –Provides a path for testing prior to implementation on Skyworker Initially kinematic modeling with a direct path to dynamic modeling Multi-robot interactions

8. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-31 Purpose of Simulation Provides a method to explore Skyworker capabilities that we are unable to test with our physical robot –Moving from standing on top of to hanging from the bottom of the truss –Construct a large scale facility –Performing various AIM tasks not demonstrated Perform and analyze multi-robot operations and their effects on the structure Study robotic efficiency Develop tools for optimizing facility construction

9. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-32 Multi-Robot Coordination Robot Coordinator –Executes pre-recorded scripts –Sequences robot actions at high level (I.e. walk to x,y) –Monitors progress Script Generator –Tool used to provide human & machine readable AIM plans –High level actions (move to, carry to, pick up, place, look at) –Initially hand generated (emacs) –Later tools will use the visualization front end –Follow-on research will develop a planning tool

10. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-33 Individual Robot Planning Translates high level plans into a sequence of steps and then to joint angle trajectories Provides a route to pass interpreted sensor data to the robot coordinator & user Separate planners used for walking and manipulating

11. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-34 Joint Control and Sensing 2 Versions –emulator –code embedded on Skyworker Local processing of video stream dramatically reduces communications bandwidth Reflex system used to perform gentle anchoring Queued joint positions/trajectories provide required low latency control

12. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-35 Simulation/EmulationSimulation/Emulation Provides feedback to emulated Skyworker Initial dynamics model will be a unity pass through Dynamics model will be updated based on characteristics of actual Skyworker

13. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-36 User Interface Provides a way for users to specify scripts to run, reset the robot and view telemetry data Visualization tool will allow for full 3D viewing of simulated robots and telemetry data from real robots Sensor simulation will utilize the visualization infrastructure to provide feedback to simulated Skyworkers

14. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-37 Visualization Software Considerations Capabilities –Ease of user interaction –Sensor simulation Leverage available from other RI projects Cost Interface

15. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-38 Visualization Packages Being Considered Viz –Developed at NASA Ames –Currently being used in a multi-robot simulation at FRC –Based on OpenInventor World Toolkit –Developed by Sense8 –Used on several previous FRC projects –Distribution costs Envision –Developed by Deneb –Limited FRC experience –Unwieldy to interface to –Extremely expensive to distribute Enigma –Developed by JSC –Used at NREC

16. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-39 Sensing Requirements Basic feedback (joint angles, velocities) Gripper proximity sensing Payload orientation sensing Inspection Localization –Correction of errors in dead-reckoning Part identification –Used for element tracking and accounting 9 Months Future

17. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-40 SensingSensing Proximity Sensing –Purpose Correct for errors in position estimation –Requirements Must have multi-centimeter range –Proposed Solution Capacitive Proximity Sensors (Capaciflectors) Payload Orientation Sensing –Tasks Recognize a payload given an estimate of its position Provide position error feedback as Skyworker manipulator attempts to grasp the payload –Requirements Recognize payload and latch points given a reasonable amount of error in position and orientation Provide x,y,z, , ,  error estimates during capture

18. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-41 Communication Issues Ease of interfacing on board software with off board software Ease of access to on board software Bandwidth considerations Availability of inter-process communication (IPC) packages over given media

19. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-42 Low Communications Layers

20. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-43 Application Communications Layer

21. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-44 IPC Package Selection Considerations Ease of Implementation Support for Peer-to-peer communication (1 to 1) Support for Publish/Subscribe services (1 to many) Operating systems supported Local experience

22. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-45 Feature Comparison IPC Package 1-11-ManyLocal Experience Platforms IPCYesAnonymousYesSunOS, Solaris, VxWorks, Linux, IRIX RTCYesNamedYesSolaris, Linux, Irix, VxWorks, Windows NT, DOS4GW Socket++YesNo Solaris, AIX, Linux, Windows 95/NT Inter-process communication will likely be performed using IPC –Supports (1 to 1) and (1 to many) messaging capabilities. –Anonymous publish/subscribe will likely by useful –Strong track record with other projects

23. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-46 TestingTesting Software components will be incrementally tested Utilize simulation to test algorithms prior to robot completion Confirm force analyses through real world testing Validate simulation by comparing simulated operations with real world operations Determine power consumption for structure walking

24. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-47 Cost Budget

25. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-48 Skyworker Organizational Chart Mobile Robot Design Class

26. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-49 Project Member Responsibilities

27. The Next Step SPACE ROBOTICS INITIATIVE Skyworker PDR 9/10/99-50 SummarySummary N-Type configuration System design –Gripper, joints –Force/gait analysis –Gravity compensation –Power –Layered control scheme –4 tier software architecture Simulation