Fall 2023 Colloquia

Unless otherwise noted, Fall 2023 colloquia will be held on Thursdays at 12:45 pm in Stanley Thomas 316. All colloquia will be available for in-person attendance as well as remote attendance via Zoom. Current Tulane faculty, staff, and students are encouraged to attend in person. Zoom details will be provided via the announcement listserv, or you may email to request the corresponding link. If you would like to receive notifications about upcoming seminars, you can subscribe to the announcement listserv.

Sept 14

Droplet: A First Step in Autonomous Underwater Construction

Sam Lensgraf | Dartmouth College

Abstract: I will present Droplet, the first free-floating autonomous underwater construction system. Droplet builds mortarless interlocking cement block structures weighing up to 100Kg (75Kg in water), the heaviest structures built by a single free-floating robot. Droplet is the first construction robot to apply dynamic buoyancy adjustments to transport construction materials efficiently.       

The underwater domain places unique challenges on construction robots: turbidity and currents make precise positioning challenging. To overcome these challenges, we take the perspective of co-design. We consider the robot and its building materials as a unit which works together to achieve construction. Through this perspective, we allow robust underwater assembly while limiting the complexity of any single component. Droplet uses a novel one degree-of-freedom manipulator that allows compliant, error correcting grasps of cement blocks. The cement blocks are designed to correct placement error by passively sliding together..  

About the Speaker: I am a Ph.D. student at Dartmouth College where I work on autonomous underwater construction. I’m interested in applying computational techniques to solve fabrication, engineering and construction problems. I’ve developed the first autonomous underwater construction robot and developed algorithms for analyzing the stability of large systems of loosely connected building blocks. I’ve also worked on developing planning algorithms that optimize fabrication plans to speed up 3D printing on standard hardware; this work received the Best Automation Paper award at IEEE ICRA 2016. My work on underwater construction is supported by an NSF GRFP fellowship.       

I graduated from Tulane in 2015 with a BS in Math and Computer Science. After undergrad, I spent several years making schedule optimization algorithms in the moving industry. I enjoy applying an engineering mindset to build robust, large-scale prototypes of novel ideas.


Previous Colloquia