1. Scarab Autonomous Traverse Carnegie Mellon 13-14 December 2007 David Wettergreen

2. Carnegie Mellon | 13 December 20071 Mission Scenario Land in crater –Direct to floor, no crater wall descent –Minimal lander Communicate by polar orbiter relay Power from isotope source, no solar Navigate in darkness –Active sensing Operate with supervised autonomy Survey multiple locations –Characterize regolith composition and physical properties –Determine nature and abundance of hydrogen Survive 7 months –25 drill sites x (5 days/site, 3 days/traverse) = 200 days Mass 200-300 kg

3. Carnegie Mellon | 13 December 20072 Rover Capability Kilometer-Scale Traverse –Terrain modeling for obstacle detection –Path planning for obstacle avoidance –Position estimation for path tracking Resource Regulation –Power –Thermal Health Monitoring –Fault Detection and Recovery –Contingent Plan Execution

4. Carnegie Mellon | 13 December 20073 Rover Architecture Health Monitor Rover Executive Vehicle Controller Mission Planner Far-field Evaluator Images Odometry Rover Interface Stop Navigator Curve & Speed State Observer State Instrument Controllers Near-field Detector Position Estimator State Telemetry Manager Inertial & Odometry ScansCommands Waypoints Telemetry Position State (All) FaultsPlans EvaluationEvalActions Specification Science Observer Instrument Manager Goal Manager Viewpoints Images Science Planner FeaturesGoals

6. Carnegie Mellon | 13 December 20075 Autonomous Traverse Total daily traverse exceeding 10km is achievable Demonstrated averages 600-1000m per command cycle

7. Carnegie Mellon | 13 December 20076 Rover Architecture Health Monitor Rover Executive Vehicle Controller Mission Planner Far-field Evaluator Images Odometry Rover Interface Stop Navigator Curve & Speed State Observer State Instrument Controllers Near-field Detector Position Estimator State Telemetry Manager Inertial & Odometry ScansCommands Waypoints Telemetry Position State (All) FaultsPlans EvaluationEvalActions Specification Science Observer Instrument Manager Goal Manager Viewpoints Images Science Planner FeaturesGoals

8. Carnegie Mellon | 13 December 20077 Terrain Model Aggregate Geometric Model Traversability Analysis Persistence

9. Carnegie Mellon | 13 December 20078 Sensor Views

10. Laser Light Striping

11. Carnegie Mellon | 13 December 200710 Path Execution Navigator evaluates –near-term driving options while –guiding the rover to its long-term goal Many possible actions considered each sensing cycle Terrain model accumulates

12. Carnegie Mellon | 13 December 200711 Position Estimation Challenges –Skidding - wheel odometry inaccurate –Kinematics - vehicle model more complicated due to changing wheelbase and Approach –No wheel odometry –Optimal (Kalman) filtering –Inertial and optical sensing

13. Carnegie Mellon | 13 December 200712 Position Estimation Inertial Measurement Unit –3-axis rotation (Honeywell HG1700 ring laser gyro) –3-axis acceleration Global Positioning System –Omnistar differential (0.1m accuracy) for ground-truth position –Can be used to correct gyro drift Kalman Filter –Integrates inertial with other motion sensing

14. Carnegie Mellon | 13 December 200713 Position Estimation Optical velocity sensor Operates with ground lighting

15. Carnegie Mellon | 13 December 200714 Dark Traverse Demonstration Developments for Scarab –Integrated Laser Scanning –Integrated Inertial/Optical Position Estimation –Developed Vehicle Controller –Integrated Scarab Motion Planning Tonight –Goal is 1-kilometer of autonomous traverse in darkness Tomorrow –Outcome –Evaluation