A Modular Architecture for an Interactive Real-Time Simulation and Training Environment for Satellite On-Orbit Servicing

Transcription

1 A Modular Architecture for an Interactive Real-Time Simulation and Training Environment for Satellite On-Orbit Servicing Robin Wolff German Aerospace Center (DLR), Germany Slide 1

2 Outline! Motivation! Physical Mock-up! Project Goal! System Overview! Servicing Tasks! System Components! Distributed Simulation Architecture! Framework Structure! Communication Layer! Implemented Modules! Summary (Servicing the Hubble Space Telescope - NASA) Slide 2

3 Motivation! On-Orbit Servicing! Analyse & Repair Failures! Lifetime Extension! Remove Space Debris! Manned Missions! Expensive and Risky! Exhausting for Astronauts! Increased Use of Space Robots! Autonomous Operation! Controlled via Tele-Operation (Ellery et al. 2008) (Astronaut during EVA - DLR/ESA) (Space Debris - NASA) (DEOS DLR/STI) (Control for Canadarm2 - MDA) (SPDM on Canadarm2 - MDA) Slide 3

4 Humanoid Service Robot! Light Weight Robot (LWR)! 7 Axes! Weight: 14kg, Payload: 14kg! Space Justin! 49 Joints! Sensors! Stereo Camera! Laser Stripe Sensor! 41 Position Sensors! 43 Torque Sensors! Workspace: approx. 1.7m! Weight: 45kg, Payload: 15kg Slide 4

5 Bimanual Haptic Interface! Based on LWR! Bimanual Control! Magnetic Safety Linkage! Tracking via Rotation Sensors in Joints! Haptic Feedback via Robot s Motors Slide 5

6 Physical Mock-up! Tele-Presence Interface demonstrated at ILA 2010 in Berlin Slide 6

7 Project Goal! Create an Immersive Virtual Environment for the Simulation of On-Orbit Servicing Tasks! Applications:! Analysis, Training, Programming & Tele-Operation of On-Orbit Servicing Tasks! Design of new serviceable Satellite Systems! Design of new Service Robots and Tools! Project Partners:! DLR Robotics and Mechatronics! DLR Simulation and Software Technology! Project Time 3 years (started Jan 2010) Operator at Ground Control Service Robot in Space VR Environment Slide 7

8 Servicing Tasks! Remove Multi-Layer Insulation (MLI)! Loosen / Tighten Screws! Plug / Unplug Cable Connectors! Remove / Insert Modules (using a Bayonet Handle)! Operate Switches! Take Measurements (e.g. using a Voltmeter) Virtual Satellite Mock-up Physical Satellite Mock-up EVA Task Sheet Slide 8

9 System Components Slide 9

10 Requirements! Real-Time Requirements! Highly Realistic Simulation! Complexity vs. Accuracy! Dedicated Machines! Shared Functionality?! Duplicate Code?! Shared Scene Description? Logic Manager F x Tele-Robot F x Haptic Device >1kHz GPU F x F x Physics Simulation ~60Hz Visualization 30-60Hz Slide 10

11 Distributed Simulation Architecture! Wraps Common Functionality! Unified Scene Management Recv. Common Processing Loop Update Simulation Step Simulation Distribute Changes Send.! Transparent Processing Loop! Asynchronous Message Passing Interpret Updates Read & Modify Collect Changes! Modular Architecture! Generic Structure! Common Interface Common Spec. Simulation State! Easily Extensible Manager Physics Haptics Visualization Scene Simulation Scene Simulation Scene Simulation Scene Simulation Communication Communication Communication Communication Server Client Client Client Slide 11

12 Communication Layer! Configurable Queuing Schemes! FIFO (Default for State Changes, Commands)! Most-Recent (Default for Updates)! Refresh & Distribution Lists! Queue only relevant Nodes! Threshold Filter! Send only significant Changes! Update Rate Monitor! Caps Update Frequency if too high! Online Performance Monitoring! Keeps an Eye on System Status! Future: Automatic Reconfiguration A C B A C D A B D C B A Scene changed D C B A x t 0 t 0 +T t 1 +T D C B A distribute distribute Slide 12

13 Implemented Modules! Haptic Device! Interface to HMI, Phantom Omni, Falcon! Collision Detection! Based on Voxmap-PointShell, and OpenHaptics! Visualization! Based on ViSTA VR-Toolkit, and InstantReality! Physics! Based on Bullet! Manager x B kinematic body C F H x C! Based on Behavior Classes (in Future: Python) hinge joint J α max static body A F sw α min x A Slide 13

14 Summary! Modular Architecture for a Distributed Interactive Real-Time Simulation Environment! Provides Underlying Infrastructure for Research Modules! First Prototype demonstrated! Desktop, 3D-TV + Haptics! VR Display (Powerwall)! Further Work! Enhance Photo-realistic Rendering! Test other Physics Engines! GPU Implementation of VPS Algorithm! Increase Complexity of Scenes! Enable Distributed Collaboration Slide 14

15 Contact Robin Wolff Simulation and Software Technology, Software for Space Systems and Interactive Visualization (SC-RV) German Aerospace Center (DLR), Lilienthalplatz 7, Braunschweig, Germany Slide 15