Fundamental Paper on Formation ControlFor CS 7631: Multi Robot Systems

Diogenes MolinaSchool of Interactive ComputingGeorgia Tech

March 15, 2012

Radhika, Nagpal, “Programmable Self-Assembly Using Biologically-Inspired Multiagent Control,” in Proceedings of the 1st International Joint Conference on Autonomous Agents and Multiagent Systems, pp. 418-425, New York, 2002.

The Paper

Problem statement and motivation Brief overview of previous work Insights from developmental biology Proposed multiagent control methodology for

programmable self-assembly◦ Origami-inspired operations for global shape specification◦ Cell biology-inspired primitives◦ From global shapes to local primitives

Simulation results Paper critique Questions

Outline

How to design/program self-assembling complex structures from locally interacting homogeneous agents?

Problem statement and motivation (1)

?????

Emerging technologies make approaches of this type attractive

But. mapping global objectives to decentralized local rules is hard

Limited agent resources Reliability

Problem statement and motivation (2)

Hierarchical and centralized approaches dominate

Can be unreliable and not fault-tolerant Expensive and complex agents can be costly Approaches based on cellular automata and

artificial life are difficult to generalize There is no framework for generating local rules

automatically Learning and evolutionary approaches

Brief overview of previous work

Biological systems are a clear proof that this can be done effectively!

The inner workings of these systems can provide inspiration

Morphogenesis and developmental biology as a source of mechanisms and general principles

Implement some of these mechanisms as a programming language

Epithelial cell behavior

Insights from developmental biology

Sheet and Agent Model

Multiagent methodology for programmable self-assembly

OSL: origami-inspired language for global shape specification

Multiagent programmable self-assembly (1)

Biologically-inspired local primitives Gradients Neighborhood query Polarity inversion Cell-to-cell contact Flexible folding

Multiagent programmable self-assembly (2)

Axiom implementation via local primitives

Multiagent programmable self-assembly (3)

From OSL to agent program

Multiagent programmable self-assembly (4)

Simulation results

Many shapes cannot be constructed using the axioms

The initialization of the sheet is providing a certain amount of “global” information

The simulation environment seems too artificial Not clear about how the folding process is

executed Some global synchronization must be occurring,

but not discussed The symmetry of the sheet might not be satisfied

in some cases, but could have a huge impact

Criticism

A. Huzita’s Axioms

B. Epithelial cells reference

http://www.bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/index.html

http://en.wikipedia.org/wiki/Epithelium