An Evaluation of Wheel-Track Systems: Abridged Version for Introduction to Robotics Course Hannah Lyness MSR Thesis Presentation

Committee: Dimitrios Apostolopoulos (Head), David Wettergreen, Venkat Rajagopalan

1 Presentation Outline

. Introduction . Motivation . Research Question . Technology History . A Novel Wheel-Track Design . Prototype Testing . Terramechanics Background . Comparative Evaluation . Conclusion

2 Wheels and Tracks Each Offer Different Advantages Wheels Tracks

“HMMWV (Humvee) High-Mobility Multipurpose Wheeled Vehicle, United States of America.” The Global Armoured and Counter-IED Vehicles Market 2011-2021. http://www.army-technology.com/projects/hmmvv/, Jason Fudge. M1A1 Abrams Tank 4th Tank Battalion. Nov. 22, 2008. URL: http://military-photo.blogspot.com/2008/11/m1a1-abrams-tank-4th-tank-battalion.html (visited on 08/13/2016). Introduction 3 Wheels and Tracks Each Offer Different Advantages Wheels Tracks

Lower system losses

Lower acoustic signature

Reduced fuel consumption

Lower system losses Larger contact surface patch

Lower acoustic signature

Reduced fuel consumption

Lower system losses Larger contact surface patch

Lower acoustic signature Reduced sinkage

Reduced fuel consumption Increased stability while firing

Lower system losses Larger contact surface patch

Lower acoustic signature Reduced sinkage

Reduced fuel consumption Increased stability while firing

Lower resistance to turning Formatted for point turns

. “We do need a new ground armored platform for our mechanized infantry and our tanks” – Army Chief of Staff General Mark Milley

Priorities for Our Nation’s Army with General Mark A. Milley. https://www.csis.org/events/priorities-our-nations-army-general-mark-milley . Gulf War: Some Lessons Learned https://www.defensemedianetwork.com/stories/gulf-war-20th-some-lessons-learned-from-the-land-war/

Motivation 4 Mobility is Key for Military Vehicles

. Increasing number of battles fought in cities

https://www.haaretz.com/middle-east-news/isis-controlled-ramadi-facing-final-iraqi-army-assault-1.5382116

Motivation 5 Vehicle Configuration Varies Greatly Across Armies HMMWV M1126 Stryker

>200,000x as of 2016 <100x as of 2016 M1 Abrams Bradley Fighting Vehicle

6,000x as of 2016 2,895x as of 2016

The Green Book 2017-2017. Oct. 2016. URL: http://digimag.ausa.org/publication/?i=338032#, http://www.military.com/equipment/high- mobility-multipurpose-wheeled-vehicle-hmmwv, https://www.goarmy.com/about/army-vehicles-and-equipment/tanks-and-fighting- vehicles.html, http://www.businessinsider.com/m1-abrams-tank-is-still-king-of-the-battlefield-2016-2, http://www.baesystems.com/en- us/product/bradley-fighting-vehicle Motivation 6 Research Question

How can we design and evaluate devices that combine the benefits of both wheels and tracks?

Research Question 7 Research Question

How can we design and evaluate devices that combine the benefits of both wheels and tracks?

. What has been tried in the past? . How is NREC designing their wheel-track system? . Do NREC’s prototypes show promise for use on a real vehicle? . How is performance estimated for wheeled and tracked vehicles? . How does the expected performance of NREC’s design compare to other systems?

Research Question 8 Beginning of Wheel Innovation

Nicolas-Joseph Cugnot’s Steam-Powered Automobile: 1769

Automotive History. San Diego Museum of Automotive History. URL: http://sdautomuseum.org/education/automotive-history

History 9 Early Technological Milestones

Volcanized Rubber: The Pneumatic Tire: 1844 Popularized 1894

Charles Goodyear. “Improvements in the Manner of Preparing Fabrics of Caotchouc or India-Rubber”. US 3633. June 15, 1844. John Boyd Dunlop. “Pneumatic Tire”. US 523270. July 17, 1894.

History 10 Early Technological Milestones

The Pneumatic Tire: Popularized 1894

Abbsry New and Used Tires. “Diagram of Radial Tire Parts and Wear Signs. 2015. URL: http://www.abbsrytire.com/diagramtire.htm.

History 11 Start of Off-Road Vehicle Design

Adolphe Kegresse’s Motor-Sledge: 1914

A 1916 Packard Twin-6 touring car from tsar Nicholas II of Russia equipped with Kegresse system (1917). URL: https://upload.wikimedia.org/wikipedia/commons/thumb/9/92/Russo-balt5.jpg/520px-Russo-balt5.jpg

History 12 Early Track Designs

Interconnected Units: Continuous Track: 1950s 1960s

Arthyr E. Benson. “Pneumatic Track”. US 32746811. May 22, 1956., Walton W. Cushman. “Endless tread and track assembly”. US 2867480. Jan. 6, 1959. Giovanni Bonmartini. “Pneumatic tubular track, driving and carrying device”. US 3155436. Nov. 3, 1964. History 13 Alternative Wheel Designs

The Resilient Wheel: The Nonpneumatic Wheel: 1909 2001

William L. Martin. “Resilient Wheel”. US 927154. July 6, 1909. Francois Hottebart. “Nonpneumatic deformable wheel”. US 6170544. Jan. 9, 2001.

History 14 Alternative Wheel Designs

Central Tire Inflation System: 1942

“Central Tire Inflation System.” Spicer Drivetrain Products. 2017. http://spicerparts.com/parts/axle/commercial-off- highway/central-tire-inflation-system-ctis

History 15 Hybrid Designs

Over Tire Tracks: Track N Go: 1955 2013

Roy A. Crop. “Wheeled vehicle convertible to crawler type”. US 2698667. Jan. 4, 1955. About Us. AD Boivin Inc. 2017. URL: http://trucktracks.com/en/aboutus/

History 16 Hybrid Designs

Elbit VIPeR: Mattracks 4TS Tire-Track: 2009 2014

Cody Underwood, Military.com. ”Robotic Warriors: The Viper”. 2017-08-23. http://www.military.com/video/logistics-and- supplies/military-equipment/robotic-warriors-the-viper/2625125923001. Dan Laux and Jason Alef. Tire to Track Transforming System. PDF file. ISTVS 8th Americas Regional Conference, Detroit, MI, Sept. 12, 2016. History 17 NREC’s Concept

. Enhance vehicle mobility and agility through a device that changes from a wheel to track at speed • Capture efficiency benefits of a wheel • Obtain higher surface area that a track affords

A Novel Wheel-Track Design 18 Factors that Limit Vehicle Torque

. Engine • Not enough power delivered to wheels . Weight Distribution • Not enough normal force . Friction • Wheels slip on ground surface . Soil Shear • Soil fails under vehicle

http://www.frc.ri.cmu.edu/projects/lri/scarab/images/WA_testing/gallery.html, https://i.ytimg.com/vi/Fyj4Q5khK9A/hqdefault.jpg, https://www.budgetdirect.com.au/blog/how-to-get-your-car-unstuck-from-mud-or-sand.html

Terramechanics Background 75 Mohr-Coulomb Criterion . • c is the soil cohesion • Φ is the soil’s angle of internal friction

Terramechanics Background 76 Thrust

. Multiply stress by area: • Increase c, increase strength • Increase φ, increase strength

Paul Muench Sean Laughery Grant Gerhart. Evaluating Vehicle Mobility Using Bekker’s Equations. PDF file. Aug. 21, 2000. URL: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA457941

Terramechanics Background 77 Thrust

. Multiply stress by area: • Increase c, increase strength • Increase φ, increase strength . Slip term:

Paul Muench Sean Laughery Grant Gerhart. Evaluating Vehicle Mobility Using Bekker’s Equations. PDF file. Aug. 21, 2000. URL: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA457941

Terramechanics Background 77 Thrust

. Multiply stress by area: • Increase c, increase strength • Increase φ, increase strength . Slip term: . Drawbar Pull: • Difference between thrust and resistances

Paul Muench Sean Laughery Grant Gerhart. Evaluating Vehicle Mobility Using Bekker’s Equations. PDF file. Aug. 21, 2000. URL: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA457941

Terramechanics Background 77 Thrust

. Multiply stress by area: • Increase c, increase strength • Increase φ, increase strength . Slip term: . Drawbar Pull: • Difference between thrust and resistances . Pull coefficient:

Paul Muench Sean Laughery Grant Gerhart. Evaluating Vehicle Mobility Using Bekker’s Equations. PDF file. Aug. 21, 2000. URL: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA457941 M.G. Bekker. Mechanics of Off-The-Road Locomotion. Institution of Mechanical Engineers James Clayton Lecture, July 10, 1962. URL: http://www.dtic.mil/dtic/tr/fulltext/u2/a457955.pdf Terramechanics Background 77 Semi Empirical Representations of Terramecanic Properties . Compaction

Richard Goetz Sean Laughery Grant Gerhart. Bekker’s Terramechanics Model for Offroad Vehicle Research. PDF file. Aug. 18, 1999.

Motivation Semi Empirical Representations of Terramecanic Properties . Bulldozing

M.G. Bekker. Mechanics of Off-The-Road Locomotion. Institution of Mechanical Engineers James Clayton Lecture, July 10, 1962. URL: http://www.dtic.mil/dtic/tr/fulltext/u2/a457955.pdf

Motivation Semi Empirical Representations of Terramecanic Properties . Sinkage

Richard Goetz Sean Laughery Grant Gerhart. Bekker’s Terramechanics Model for Offroad Vehicle Research. PDF file. Aug. 18, 1999.

Motivation Low Ground Pressure is Vital for Traveling on Soft Terrain . Ground pressure often directly correlates to percent of traversable landscapes

William E. Willoughby Jody D. Priddy. “Clarification of vehicle cone index with reference to mean maximum pressure”. In: Journal of Terramechanics 43.2 (Apr. 2006), pp. 85–96. URL: http://www.sciencedirect.com/science/article/pii/S0022489804001120,

Terramechanics Background 78 Ground Pressure

. Most simply: weight divided by contact patch • . However, pressure is not constant under a body

• Mean Maximum Pressure • Vehicle Cone Index

https://www.tekscan.com/force-plate-pressure-technology, D. Rowland. A Review of Vehicle Design for Soft Ground Operation. 5th International Conference for Terrain Vehicle Systems, 1975. URL: http://www.slideshare.net/wolfhag/tracked-vehicle-ground- pressure Terramechanics Background 79 Comparison of Existing Technologies

HMMWV Example Vehicle M113

Weight: 2.75 tons Weight: 10 tons Weight: 13.6 tons Wheel Width: 12.5 in Wheel/Track Width: 14 in Track Width: 15 in Wheel Diameter: 37 in Wheel Diameter: 33 in Track Length: 105 in Track Length: 100 in Track Pitch: 6 in Track Pitch: 6 in Wheel Diameter: 23.62 in Track Wheel Diameter: 20 in

http://www.military-today.com/trucks/hmmwv_images.htm http://www.military-today.com/apc/m113_images.htm

Comparative Evaluation 80 Comparison of Existing Technologies ] [psi] [ unitless VCI and Sinkage [in] Sinkage Coeficient MMP Pull

Comparative Evaluation 81 Conclusions

. There is a gap in current wheel track technology for a device that can support a large vehicle and transition at speed.

. A reconfigurable wheel track would offer a greater range of surface pressures compared to existing devices

Conclusion 84 Future Research

. Incorporation of grouser and suspension research . Comparison of analytical and empirical models with computational Terramechanics methods

Moreland, Scott. “Traction Processes of Wheels in Loose, Granular Soil.” Carnegie Mellon University. 2013. M. Mahomodi-Kaleibar, I. Javanshir, K. Asadi, A. Afkar, A. Paykani. “Optimization of suspension system of off-road vehicle for vehicle performance improvement.” Journal of South University. 2013. Conclusion 85 Thank You

Dimi for encouraging me to pursue my research as far as it could take me, from Russia to Windows XP. Dave, Venkat for guiding me through the academic research process. Rich, Matt, Ed, Karl, Steve, John for showing me how professional a professional engineering team operates. Eugene, Nishant, Dave, Sherman, Graham, Andrew for translating, being soundboards for ideas and teaching me new skills. The Entire NREC Team for being incredibly welcoming and helpful. B.J., Suzanne, Alan, and CMU RI for enabling my research to happen. My Professors, Mentors, Family and Friends for your limitless support.

Thank You 89