Collective Robot Construction of Discrete Lattice Structures

My research focuses on robotic construction of discrete lattice structures. Once we have individual robotic construction, we will want to look at collaborative construction with multiple robots.

           

• what is the goal?

        The goal of this project will be to develop a tool for evaluating various approaches for robot construction of lattice structures of arbitrary scale and shape.

        This tool will (for now) not zoom in to the level of individual voxel placement, rather, it will focus on global geometry strategies as it relates to path planning for multi-robot groups.



• how will you evaluate progress?

        Initial experiments will be constrained to 2D geometries, with the final goal of addressing 3D geometries.

        Hierarchy can be introduced, which can lead to higher performance, but also higher part count and geometric complexity.


• what is the prior art?

                 Collective robot behavior is a well-researched topic. Collective robot construction, less so.

                 TERMES

                 KILOBOT

                 AMAS

                 NIGL

• what techniques will you use?

It looks like a gradient descent algorithm could work, but would likely need iterative sensitivity updating to prevent local minima from creating problems.


• what questions will you need to address?

                -Interesting things to address include

                    -resource allocation

                    -centralized v decentralized construction strategies

                    -dynamics of robots (with mass) walking around on the structure as its being built

    progress update (3/23)

               In thinking about the swarm construction environment/simulator, here's what the GUI could look like

        i have recently been interested in the dynamics of the structure and the robot as it builds the structure. this is a fairly unexplored topic. most climbing robots consider their structure to be A) rigid, and B) fixed.

        For space construction, both (A) and (B) aren't necessarily true. Most space structures are optimized for mass, and therefore at large scale become flexible. Further, all space structures are not necessarily fixed. They are technically floating in microgravity, and their orientaiton, position, and direction of travel is governed by spaceship controls (ie: propulsion).

        Therefore, a second topic would look at these (comparatively) smaller scale interactions. While (A) is indeed interesting, it will be more tractable to look at (B) and only consider rigid body motions. The design tool/simulator would then investigate how a robot with much greater mass than the structure it is building would alter the center of gravity (CG) of the structure, and how that would result in rotation of the structure in 2D (for now) space.

Here's a sketch:

Moving CM/CG on different structure geometries


Conservation of angular momentum in a closed system

Here is an interesting paper:
"Coordinated Control of Space Robot Teams for the On-Orbit Construction of Large Flexible Space Structures"

            progress update (4/25)

                           I've been busy for the past couple weeks doing animations for a collaboration with NASA, but they are very relevant to the class project, in that basically I made animations of what the class project will do in an interactive way: