UWB for Lunar Surface Tracking. Richard J. Barton ERC, Inc. NASA JSC

Transcription

1 UWB for Lunar Surface Tracking Richard J. Barton ERC, Inc. NASA JSC

2 Overview NASA JSC is investigating ultrawideband (UWB) impulse radio systems for location estimation and tracking applications on the lunar surface: Localization and tracking of mobile nodes on the lunar surface lightweight, low-power network deployed on the lunar surface to track autonomous vehicles or EVAs Indoor (habitat) asset localization track and record the storage location of arriving inventory locate assets that are re-distributed on a regular basis track rovers within the environment Precision tracking of robots or robotic manipulators precision tracking and guidance of remotely operated vehicles track and control the position and orientation of robotic manipulators with high precision 2

3 Outline NASA JSC UWB Systems Group Background on UWB Current UWB Development at NASA JSC UWB Two-Cluster AOA Tracking Prototype System Questions 3

4 JSC UWB Systems Group Analysis Team Hardware Team Software Team Administrative Liaison Algorithm Development System Simulation Performance Evaluation Proposal Development Hardware Design System Testing Product Investigation Software Development Software Maintenance Internal Networking External Networking Funding Channel Order and Purchase David Ni Dickey Arndt Richard Barton Phong Ngo Chau Phan John Dusl Michael Conover David Ni Julia Gross Kent Dekome Michael Conover Dickey Arndt Phong Ngo Chau Phan John Dusl 4

5 Background on UWB - Definition UWB signal - any signal with fractional bandwidth greater than 0.20 or total bandwidth greater than 500 MHz 5

6 Background on UWB - Impulse Waveform Typical UWB impulse waveform is the Gaussian monocycle 6

7 Background on UWB - Time and Frequency Resolution UWB impulse signals are the time-frequency dual of sinusoidal signals 7

8 Background on UWB - Advantages Robust against multipath interference - minimal fading, LOS signal can be isolated and detected Minimal mutual interference with conventional narrowband systems Wide bandwidth supports very high data rates LPI/LPD characteristics - low PSD and short time duration hard to detect by conventional means 8

9 Current Development at JSC - Inventory Tracking UWB-RFID for ISS inventory tracking Evaluate UWB-RFID system Sapphire DART Customize the system and enhance the tracking performance 9

10 Current Development at JSC - Inventory Tracking Laboratory test configuration for Sapphire DART Processing Hub Cross-over Ethernet Cable Rx 2 Rx 3 y Asset Tag #2 Reference Tag x Asset Tag # 1 Rx 1 Rx 4 10

11 Current Development at JSC - Precision Tracking UWB TDOA high resolution proximity tracking for robonaut Theoretical analysis and simulation for TDOA proximity applications Lab tests show sub-inch tracking resolution 11

12 Current Development at JSC - Precision Tracking Laboratory test configuration for high resolution proximity tracking R2 R1 R0 R3 12

13 Current Development at JSC - Long-Range Tracking UWB two-cluster AOA tracking prototype system Excellent tracking performance - less than 1% error at ranges up to 3500 feet No RF interference with on-board GPS, video, audio, and telemetry systems 13

14 UWB Two-Cluster AOA Tracking Prototype System Two-cluster design TX r1 r2 A1 θ1 a Rx1 θ1 A2 d A3 θ2 a Rx2 A4 Cluster I Cluster II 14

15 UWB Two-Cluster AOA Tracking Prototype System Test site - Arizona meteor crater SCOUT Camp EC/Suit Camp 15

16 UWB Two-Cluster AOA Tracking Prototype System Test baseline configuration 16

17 UWB Two-Cluster AOA Tracking Prototype System Tracking target - SCOUT vehicle 17

18 UWB Two-Cluster AOA Tracking Prototype System Tracking results - accuracy * Measured by GPS Measured by UWB System 3000 Y-Axis Distance (feet) X-Axis Distance (feet) Accuracy Comparison: GPS vs. UWB System 18

19 UWB Two-Cluster AOA Tracking Prototype System Tracking results - trajectory Y-Axis Distance (feet) X-Axis Distance (feet) Trajectory: UWB System tracking the SCOUT vehicle 19

20 UWB Two-Cluster AOA Tracking Prototype System Conclusions UWB tracking system can co-exist with other RF communication systems aboard SCOUT Tracking resolution less than 1% of range (up to 3500 feet) successfully demonstrated Moving target can be tracked in real time (update rate = 10 Hz) Steerable antennas have been implemented to increase tracking coverage Two-way voice communication has been integrated with tracking system 20

21 UWB Two-Cluster AOA Tracking Prototype System Future work Integrate video with communication/tracking system Add additional clusters to baseline to improve performance Add wireless (802.16) connectivity between clusters to increase tracking coverage Refine initial AOA location estimates with maximumlikelihood estimates to improve accuracy Add multiple target capability and multi-hypothesis target tracker 21

22 Questions?

23 Backup Slides

24 Sapphire DART (Digital Active RFID & Tracking) Overview Vendor Specifications: Frequency: 5.94 to 7.12 GHz Accuracy: within +/- 1 foot Tag battery life: in excess of 4 years (1 Hz rate) Tag read range: up to 160 ft indoors Hub is configurable to accommodate various configurations/coverages 24

25 Sapphire DART Evaluation Kit PAL651-EK Evaluation kit: One processing hub Four receivers, each with its own antenna Eleven tags, one for use as a reference tag Four 150 ft CAT 5E cables Management software and documentation Tracking technique: Short burst of pulses transmitted by the active tags received by sensors located at the periphery of the coverage area One tag designated as a reference tag and used for automatic system calibration and synchronization Location of asset tags based on the TDOA technique Accurate and reliable 2D TDOA tracking requires at least 4 receivers (3D will require at least 5 receivers) 25