SOYBOTS: MOBILE MICRO-GARDENS start-up, each robot is calibrated to a light value beneficial to the growth of the soybean plants. After comparing readings of Shannon C. McMullen (educator, artist), Purdue University. VISAP’14 Email: <[email protected]>. two photocells (LDRs) mounted at the front corners of laser- cut acrylic planter boxes, a robot then sets out to find sites with Fabian Winkler (educator, artist), Purdue University. light values greater than this threshold. If in a given amount of Email: <[email protected]>. time no such location can be found, the threshold is decreased See <www.mitpressjournals.org/toc/leon/50/5> for supplemental files by a specified quantity and the robot continues its search. associated with this issue. Once a robot has found a place with light exposure matching the required value, it rests for a predefined period of time, then Abstract increases the light threshold by a set amount and continues its Gardens express ideas and social relations; some are sites where art search for locations with even better sun or grow-light expo- and technology produce material realities, construct social narratives sures. This system is self-regulating and can easily adapt to and visualize politics. Soybots: Mobile Micro-Gardens unite code, changing light conditions over time. robotics and soybean plants (robotanics) to create a speculative responsive installation that suggests questions about climate, place Each Soybot is also equipped with infrared (IR) distance and agriculture implicated in contemporary practices and values. sensors on its front bumpers. These sensors enable the robot Soybots utilize light sensors to track sunlight intensity or to locate to steer away from obstacles such as walls, furniture and exhi- LED grow lights. As self-pollinating organisms in combination with a light-seeking mobile robotic platform, soybean plants metaphorically bition visitors. If obstacle detection with the IR distance sensor address the continually evolving interdependence between humans fails (e.g. certain types of black leather do not reflect sufficient and cultivated crops, as well as the underlying political nature of light back to the sensor), each robot can still use its built-in photosynthesis. bump sensors for navigation. Furthermore, the Soybots can be confined to an area defined by beams of infrared light that they Soybots are robotanic beings that utilize light sensors to seek sunlight or to locate LED grow lights. Uniting code, robotics are programmed not to cross. and soybean plants, these autonomous nature-technology hybrids roam interior spaces, creating a speculative respon- Visualization Robots send their positional data—distance measures and rota- sive installation that suggests questions about future relations tional angles acquired using dead reckoning strategies [2]— between climate, place and agriculture. Additionally, a real- via XBee modules to a host computer. This computer displays time screen-based graphic display pictures the robots’ move- interpretations of data in three ways: ments in space as an increasingly tangled web of paths— densest where light exposure is ideal. In effect, the visualiza- 1) as a map created with Processing that draws real-time tion defines an evolving architecture of light and creates an spatialized energy information; archive of photosynthesis [1]. 2) a real-time set of bar graphs showing battery charge level and comparative light values for the photo-sensors.; and Phototropic Robot Behavior 3) a line graph charting the history of the statistical relation- The Soybots’ main technical components consist of a low- ships between the average light exposure for each robot per cost iRobot Create platform enhanced with light sensors and day and the distance it traveled over the whole duration of controlled by a custom-programmed Arduino board. Upon the installation. Fig. 1. Screenshot of the artwork’s visualization component (on the left) with a system overview of a Soybot (right inset). (© Shannon C. McMullen and Fabian Winkler) ©2017 ISAST doi:10.1162/LEON_a_01232 LEONARDO, Vol. 50, No. 5, pp. 507–508, 2017 507 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/LEON_a_01232 by guest on 03 October 2021 The first two occupy the majority of the display window, drawing the path of each robot through the gallery while find- VISAP’14 ing places of optimum light conditions. Variation in line color represents the light level ranging from saturated green (opti- mum light exposure) to light green (low light levels). Visually denser areas—in terms of overlapping lines and color satura- tion—represent locations of better light conditions, which attract the Soybots’ phototropic control algorithm. In the example included here (Fig. 1), the robots are flocking around an LED grow light. In exhibition spaces with changing natural light, the visually denser areas will shift spatially over the course of the day, revealing changing patterns of sun inten- sity. This evolving map is further influenced by the presence of exhibition visitors, standing in the way of the robots, creating darker areas through their shadows, or actively influencing navigation with flashlight beams. Thus, the map is a graphic representation of a complex negotiation among the robots, the environment and human intervention—all leaving marks Fig. 2. Soybots installation at IEEE VIS 2014 Arts Program (VISAP’14) in Paris, France: autonomous robots with live measured in energy gained and expended. soybean plants, screen with visualization component and LED As one observer of the work has remarked, this graphical grow light. (© Shannon C. McMullen and Fabien Winkler. representation suggests that “the process of photosynthesis is Photo: Shannon C. McMullen.) more deeply entangled with technology and cultural-based ecologies than perhaps previously imagined. Rather than being simply a translation of light into plant matter, photosynthesis autonomous nomadic nature of the robot/plant hybrid begs the extends through food webs to include the relationship between questions, what do plants want, and will their desires/needs be humans and technology” [3]. satisfied in a space created by human desires/needs? The line graph in the lower third of the visualization window The gardens in our work express ideas and social relations; allows a comparison to be drawn between the efforts made to they become sites where art and technology produce material reach locations with optimum light conditions and the light realities, construct social narratives and visualize politics. energy harvested by the plants. For example, during sunnier days (higher light levels in the gallery) the Soybots do not have Acknowledgments to travel far to satisfy the plants’ needs. Whereas on days with This work was made possible through the generous support of a Purdue University overcast conditions, they move much more, traveling farther College of Liberal Arts Research Initiative Grant 2013/14. Additional technical assistance in the development of the robot control code was provided by Zheng to find brighter locations or relying on LED grow lights to Qing Li, and the soybean plants for this exhibition were grown by Jörg and Astrid support plant growth. Thus, the graph illustrates a relationship Winkler. between energy use and environmental impact, raising ques- tions about energy balance—or imbalance—suggesting the References and Notes need for increased electrical energy from the Soybots’ batteries Based on a presentation given at VISAP’14, 9–14 November 2014, Paris, when natural light energy is low. France. The IEEE VIS Arts Program (VISAP) is a forum that encourages dialogue about the relationship between aesthetics and visualization. The theme of VISAP’14 was Art+Interpretation. Critical Gardening 1. A documentation video of the Soybots installation at IEEE VIS Arts Program Soybots: Mobile Micro-Gardens continues the artists’ search (2014) is available at <www.gardensandmachines.com/SoyBots>. for effective representations of shifting relations between 2. See Tod E. Kurt, Hacking Roomba (Indianapolis: Wiley, 2006) pp. 131–150. nature and technology that began with the public art installa- The artists decided against a more precise localization technique using a scan- tion National Security Garden [4]. McMullen and Winkler ning laser rangefinder coupled with SLAM (Simultaneous Localization and Mapping) techniques to keep overall project costs reasonable and the number of see this work, and other developing projects such as A Green- robots scalable. house for Critical Gardening Practices and The Algorithmic 3. Comment from an anonymous reviewer for the SIGGRAPH 2014 Art Show. Gardener: Tales of Nature and Code [5], as a critical garden- ing practice that questions current practices and speculates 4. Shannon C. McMullen, “National Security Garden: A Discursive Field,” The Art of Research: Making Reflecting and Understanding (Helsinki: Aalto about possible agricultural and robotic futures through inter- University School of Arts, Design and Architecture, 2012), <designresearch pretive gardens. As a major agricultural crop, soybean pro- .aalto.fi/events/aor2012/download_content/selected_papers/shannon_ duction is paradoxically at the heart of both global warming mcmullen.pdf>. problems and suggested solutions to food security issues. 5. Shannon C. McMullen and Fabien Winkler, A Greenhouse for Critical Soybean plants perfectly—though invisibly—embody the Gardening Practices (work-in-progress title) and The Algorithmic Gardener: Tales