Autonomous Rover Reflectance Spectroscopy with Dozens of Targets

Autonomous Rover Reflectance Spectroscopy with Dozens of Targets Francisco Calderón David R. Thompson David Wettergreen Robotics Institute Carnegie Mellon University NASA ASTEP NNG 0 -4 GB 66 G Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 1

Agenda Introducing spectrometer transects Image analysis and rock detection Visual servo procedure Amboy field test results Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 2

Previous work in autonomous spectroscopy Antarctic Meteorite Search (Pedersen et al. , 2001) Single Cycle Instrument Placement (Pedersen et al. , 2004, Madison 2006, etc. ) OASIS system (Castaño et al. , 2005, 2006, 2007) Autonomous spectrum intepretation (Bornstein et al. , 2005, etc. ) Our goal: multiple targets, many samples Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 3

Spectrometer transects Scientists specify: Goal location Time budget (allocated to traverse segments) Rover: Navigates to the goal Detects and tracks multiple target features Pauses to collect spectra while time remains Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 4

Architecture spectrum 1. Image analysis SIFT keypoint detection 2. Data acquisition rock database visual servoing rock detection VIS/ NIR cameras pan/tilt correspondence search Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 5

Image analysis: Rock detection [Open. CV libraries, Thompson and Castaño 2007] Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 6

Modified Viola / Jones method Filter Cascade A (Left-lit) max input image Filter Cascade B (Right-lit) detected rocks [Open. CV libraries, Calderón and Thompson 2008] Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 7

Typical spectrometer targets Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 8

Spectrometer targeting ASD Field. Spec Pro VIS/NIR Spectrometer Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 9

1. Calibration with white reference Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 10

2. Feedforward kinematic pointing Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 11

3. Visual servo: SIFT matching database Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 12

4. Visual servo: feedback control Stereo depth -> desired (u, v) Pan-tilt servo update with image Jacobian (�u, �v) Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 13

Rock tracking example Movie courtesy Dom Jonak, CMU RI Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 14

Spectrum interpretation 1. 0 reflectance 0. 8 0. 6 sediment 0. 4 0. 2 basalt 0. 0 350 850 1350 1850 wavelength (nm) 2350 Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 15

Amboy Crater field tests Our system: 21 rocks (± 3. 9) in 40 minutes, automatic target selection Without rock detection and pointing: 0 rocks 50 m Rock detection precision: 90. 8% (± 2. 6) Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 16

Amboy Crater field tests 50 40 Lost Track Miss 30 Miss 20 10 Trial Rock Spectra 1 Rock Spectra 2 Rock Spectra 3 Lost Track Miss Rock Spectra 4 Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 17

Accomplishments Fast spectroscopic profiles of rover transects Automatic spectroscopy calibration and interpretation Integrated feature detection, tracking, and mapping Average >1 rock spectrum per 2 minutes of rover travel time Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 18

Thanks! CMU Field Robotics: Dom Jonak, James Teza ASU: Ron Greeley, Shelby Cave, Phil Christensen NASA ASTEP NNG 0 -4 GB 66 G Autonomous Rover Spectroscopy with Dozens of Targets / i. SAIRAS 2008 / Caldeón, Thompson, Wettergreen 19