Exploring Architectural Robotics with the Human Hive
Michael Philetus Weller
Computational Design Lab
Carnegie Mellon University
Pittsburgh, PA
philetus@cmu.edu
Ellen Yi-Luen Do
ACME Lab
Georgia Institute of Technology
Atlanta,USA
ellendo@cc.gatech.edu
ABSTRACT
We present an activity we developed to demonstrate
bottom-up form construction, the human hive. Participants
team up to construct a hive structure from large
interlocking cardboard blocks. Each participant is given a
visual rule that describes where new cells should be added
to the hive. The design of these rules guides the form of the
structure that emerges from this uncoordinated activity.
Bottom-up, distributed methods for specifying physical
forms and behaviors are central to the emerging field of
architectural robotics that deals with designing objects
composed of self-reconfiguring materials.
Author Keywords
Stigmergy, distributed algorithms, education.
ACM Classification Keywords
H1.2. [Models and Principles]: User/Machine Systems.
General Terms
Experimentation.
INTRODUCTION
Systems of homogeneous robotic modules currently under
development [3] promise to provide robotic building blocks
suitable for realizing furniture and entire buildings [2].
Such a structure could be reconfigured on demand by
downloading a new program onto the computationallycontrolled materials it is composed of. We call this
emerging field of design with reconfigurable materials and
structures architectural robotics. To support design in this
new medium we need new tools that allow us to express
desired forms as algorithms, to visualize dynamic
transitions, and to maintain constraints during these
transitions. But even more importantly, we need to prepare
designers to think in terms of distributed algorithms, and
understand what it means for form to arise bottom-up from
the interaction of an ensemble of cooperating modules
rather than top-down from the execution of design
drawings.
Figure 1: Hive built with bloxes and the tower ruleset.
among a group of people they can collaborate to produce a
structure much as wasps and termites do, for example the
tower shown in Figure 1. By participating in this activity
people can appreciate how a particular shape emerges from
their efforts even though no one in the group knows what
the final shape is supposed to look like. Indeed, the specific
final shape is not pre-determined; although the rules
constrain it, they may be applied in different sequences or
to different local sites to produce different outcomes.
To help people explore this mode of expression we have
created a design activity called the human hive. We have
created a series of rulesets that when executed produce a
variety of different physical forms. Each rule is represented
as a picture on a card that specifies where to place a cubic
block. By distributing the rule cards for a particular ruleset
Stigmergy
We created this activity to introduce people and designers
to a new way of thinking about form. To direct an ensemble
of self-reconfiguring building blocks to change their shape
we must give each block instructions to follow. One model
for directing a large number of agents to collaborate to
create a structure is the stigmergic method employed by
wasps and termites [1]. With stigmergy a swarm of wasps
building a hive do not communicate with each other
directly. Rather, their behavior responds to changes in the
Copyright is held by the author/owner(s).
C&C’09, October 26–30, 2009, Berkeley, California, USA.
ACM 978-1-60558-403-4/09/10.
439
Figure 2: The 8 rules of the tower ruleset. Each participant gets one rule, and gets a block matching the color of the rule’s outline
(white: 0, 1, 3 & 4; gold: 2, 5, 6 & 7). When a 3x3x3 area of the current structure matches your rule, you add your block in the center.
set (more than one person might have the same rule). We
instructed the participants to pick up a block (white, if their
rule card was white; gold if they had a gold rule card), and
look for a place in the structure that matches the diagram
on the rule card where they could attach the block.
structure of the hive they are building. Each wasp crawls
around the growing hive structure looking for one of a
group of stimulating local conditions, a particular
configuration of cells. When a wasp finds one of these
stimulating configurations it builds a new cell in that spot,
changing the structure of the hive and potentially
generating a new stimulating configuration.
We tried two different rulesets, the tower ruleset, pictured
above, which is designed to always converge to the same
shape, as well as a cloud ruleset that would produce
lilypad-like shapes that would vary depending on the order
the rules were applied in. The cloud ruleset had issues with
structural stability as it was coming together, but we felt the
tower was very successful and we ran it twice, with
participants of all ages as shown in Figure 1.
The Human Hive
As part of Robot 2501, a summer-long citywide celebration
of robotics in Pittsburgh, we organized a public event at
The Mattress Factory, a local gallery. In this event, visitors
participated in building structures using the stigmergic rulefollowing model described above. The participants were of
all ages, from toddlers to seniors, and except for two of our
colleagues, no one participating had previous knowledge or
experience with stigmergy or modular robotics.
Discussion and Future Work
From our experience with the workshop we felt that the
group interaction provided by assembling the bloxes hives
with an individual rule card for each person was very
successful. We also noticed that people enjoyed building
the tower ruleset by themselves with the small plastic
cubes. The biggest failing was that the other rulesets we
developed were less successful.
The building blocks of the Human Hive were “bloxes”2, 3dimensional cardboard structures approximately 10 inches
(25 cm) on each side. Each blox is made of six interlocking
flat panels and overall it forms a cubic block. Each face of
the block is shaped so as to interlock with its neighbors, so
bloxes can be built up into large structures that are more or
less stable.
In the future we would like to keep the tower ruleset, but
also develop a few more rulesets that demonstrate both
stochastic rules (that do not produce the same structure
every time) and more diverse forms. We would also like to
experiment with having more than one swarm going at the
same time. We suspect people would appreciate the process
better if they could see how another group executed the
same ruleset.
We began by introducing the participants to overall idea.
We explained how wasps build nests by following local
rules, and that we were going to pretend we are wasps and
build a human hive. To practice, we began by playing with
omnifix cubes3, small colored plastic cubes that snap
together in lego-fashion. To build with the ruleset (the
tower ruleset is shown in Figure 2) you start with a single
seed block and then look for a rule that matches a 3x3x3
area shown by a rule and then add a block of the
appropriate color. For example, tower 3 matches the initial
gold seed block and indicates you should place a white
block on top of it. Adding a block potentially triggers new
rules to match, for example after tower 3 is applied, tower 0
then matches twice, on either side.
ACKNOWLEDGMENTS
This research was supported in part by the National Science
Foundation under Grant ITR-0326054.
REFERENCES
[1] Theraulaz, G and Bonabeau, E. Modelling the
Collective Building of Complex Architectures in
Social Insects with Lattice Swarms. Journal of
Theoretical Biology, 177, 4. (1995), 381-400.
After we had acquainted the participants with the basic idea
of stigmergic construction, we began to build the human
hive. We placed a large pile of bloxes in the corner of the
room: some were white and some we had painted gold.
Each participant received a single rule card from the tower
1
http://robot250.org
2
http://bloxes.com
3
http://www.eaieducation.com/530132.html
[2] Weller, M P and Do, E Y-L. Architectural Robotics: A
New Paradigm for the Built Environment. Design
Sciences & Technology, EuropIA, (2007), 353-362.
[3] Weller, M P, Kirby, B T, Brown, H B, Gross, M D and
Goldstein, S C. Design of Prismatic Cube Modules for
Convex Corner Traversal in 3d. Intelligent Robots and
Systems (IROS), IEEE, (2009), (to appear).
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