A Design Conceptfor a Robotic Lunar Regolith Harvesting

System

Stanford Lunar Regolith Excavation Presentation Authors:Matthew Maniscalco, Nicolas Lee, Nathan Salowitz, Forrest Hetherington, Elizabeth Grote, Shandor Dektor, and Professor Robert Twiggs

ICRA '07 Space Robotics Workshop April 14, 2007, Rome, Italy

Presentation Outline

• Motivation for Robotic Regolith Harvesting• Lunar Environment• Robotic System Requirements

– Tasks– Constraints

• System Concept– Modularity– Semi-Autonomous Control System– Supporting Infrastructure

http://universe-review.ca/I14-13-Moonbase.jpg

Motivation for Robotic Regolith Harvesting

• Establish a permanent moon base– Robotic preparation of station and site– In-situ resource utilization (ISRU)“Never send a human to do a robot’s job”

• Save money • Reduce risk

http://universe-review.ca/I14-13-Moonbase.jpg

Lunar Environment• Radiation

– Lunar radiation environment consists of solar wind, solar flares, and cosmic rays

– Destructive for both humans and machinery

• Composition of regolith– Oxides of:

Si, Fe, Al, Ca, Mg, Ti, Na, Cr, Mn, K, P, and S

• Uses/products from regolith– Oxygen– Building materials – Helium-3– Ultimately more complex

products• Solar panels, computer chips,

fiberglass www.moonminer.com/MOONDUST-ON-BLACK-RSC.JPG

Lunar Environment• Adverse regolith characteristics –

dust– Fine– Sharp– Electrostatically attracted

http://www.gc.maricopa.edu/earthsci/imagearchive/Coralpnk1.JPGhttp://www.astro.virginia.edu/class/oconnell/astr121/moondust.html

Robotic System Constraints Dust Migration

• Anthropogenic– Launches and landings– Construction– Regolith excavation

• Natural– Terminator – Day night ion charging– Meteor impacts

http://vesuvius.jsc.nasa.gov/er/seh/sei52.GIF

Robotic System Requirements

• Tasks– Construction– Harvesting of Regolith

• Constraints– Radiation Protection– Dust Mitigation– Operational Efficiency

http://ares.jsc.nasa.gov/HumanExplore/Exploration/EXLibrary/DOCS/Images/EIC033-2.GIF

Robotic System TasksConstruction

• Assembly tasks• Radiation protection

– Bury manned structures– Robotics reduce EVA trips/time

• Dust mitigation– Reduced EVA’s– Constant Cleaning

• Landing and launch port• Solar collection stations• Rover repair station• Cleaning systems (electrostatic, ultrasonic, physical

sweepers, fluids)

http://www.affordablespaceflight.com/moonbase.gif

Robotic System Tasks

Harvesting Regolith

• Harvesting tasks– Clean– Clear– Dig– Transport

http://www.psrd.hawaii.edu/WebImg/lunox.gif

Robotic System Constraints Radiation Protection

• Radiation hardened electronics• Robust and simple software

– Suitable for rad hard (slower) processors – Failures easily detected and corrected

Robotic System Constraints Dust Mitigation

• Four level approach– Prevention– Containment– Equipment Protection– Durable Design

http://nssdc.gsfc.nasa.gov/planetary/lunar/images/as11_40_5878.jpg

Robotic System Constraints Operational Efficiency

• Problems– Specific cost of launch– Different rates of wear on equipment – Downtime for repair and recharge

• Solution– Modularity

• Less total equipment• Replace worn parts• Operate during repair & recharge

http://www.nasa.gov/images/content/149768main_calv_launch_330.jpg

The System Concept• Modularity

– The Core Platform– The Suite of Modules

• Semi-Autonomous Control System • Supporting Infrastructure

The System ConceptModularity

• Flexibility of 3-point PTO for tractors– Maximizes functions performed by mass

• Worn out parts can easily be replaced– Minimizes downtime for part repair– Allows full use of parts with different lifespans

• Swappable batteries– No recharge downtime for rovers

The System ConceptThe Core Platform

• Power system, electronics, control, data handling, and communication

The System ConceptThe Core Platform

• Interface: 3-points and wiring

The System ConceptThe Suite of Modules

• Blade Actuator Module (BAM) - Bulldozer• Regolith Transportation Module (RTM) - Truck• Integrated Conveyor Module (ICM) - Excavator

– Rotating Wheel Attachment (RWA) - Wheel digger– Rotating Sweeper Attachment (RSA) - Power broom

• Articulated Digging Module (ADM) - Backhoe• Articulated Loading Module (ALM) - Loader

The System ConceptThe Suite of Modules

• Blade Actuator Module (BAM) - Bulldozer

The System ConceptThe Suite of Modules

• Regolith Transportation Module (RTM) - Truck

The System ConceptThe Suite of Modules

• Integrated Conveyor Module (ICM) - Excavator

The System ConceptThe Suite of Modules

• Integrated Conveyor Module (ICM) - Excavator– Rotating Wheel Attachment (RWA) - Wheel digger– Rotating Sweeper Attachment (RSA) - Power broom

The System ConceptThe Suite of Modules

• Articulated Digging Module (ADM) - Backhoe

The System ConceptThe Suite of Modules

• Articulated Loading Module (ALM) - Loader

The System ConceptControl System

• Machine tool style task assignments– High level thinking and analysis

done elsewhere, CNC script sent robots.

• Semi-autonomy– Advantages over haptic, force-

feedback– Advantages over fully autonomous

http://www.belmont.k12.ca.us/ralston/programs/itech/SpaceSettlement/spaceresvol4/images/humanfig19.JPG

CommandScript

ScriptedTask

Completed

SensorData

Acquired

Obstruction

OperatorAnalysis

NoInterference

BeginExcavation

Process

The System ConceptControl System

The System ConceptSupporting Infrastructure

• Solar Recharging Station• Repair/Reassignment Shop• Regolith Processing Facility

– Conveyor system• Human Habitat• The Port – landing and launch

http://www.hardyart.demon.co.uk/webimage/advbase.jpg

The System ConceptSupporting Infrastructure

Lower DustTolerance

Higher DustTolerance

Geographic Separation

ThePort

Habitat

SolarStation

RepairShop

RegolithProcessing

Facility

RegolithExcavation

andConveyor

Area

Conclusion• Modular, Semi-Autonomous System

– Lowers cost– Increases power and mass efficiency– Increases versatility– Reduces human exposure to dust and

radiation– Harvests resources and frees astronauts for

less mundane tasks

http://www.thespacereview.com/archive/93a.jpg

CreditsThanks to:

SSDL, Stellar Solutions, Pumpkin Inc., Stanford on the Moon, andNASA for public domain imagesAdditional Student Contributors:James Mack, Dave Johnson, Katie Davis, Geoffrey Bower, Jordan McRae

http://icb.nasa.gov/2003_Annual_Report/lunar_rover_II.jpg

The End