Designing urban robots for hybrid placemaking experiences
By: Marius Hoggenmüller
Tags: Smart Cities, Design, Robotics, Digital Placemaking, Qualitative Research

by Marius Hoggenmueller, Luke Hespanhol & Martin Tomitsch (Design Lab, School of Architecture, Design & Planning, University of Sydney)

Governments, organisational institutions and tech companies around the world are not only collecting and analysing data, but increasingly turning to urban robots for automating processes and services, with the aim to make cities more efficient and productive. However, the development of so-called smart cities also triggered heated debates among thought leaders and scholars, with some arguing that the matter of productivity should be dissociated from speed and efficiency and instead questioning how to make cities more liveable and healthier, regarding people as co-creators instead of simply consumers, and create cities for slowing down.

In this exploratory design research project, we created Woodie, a slow-moving robot that draws on the ground using conventional chalk sticks. Capable of drawing various predefined designs, Woodie uses the public space as a large horizontal canvas, producing simple line drawings. Building on previous research on pervasive urban displays, we were interested how an urban robot could replicate the qualities of non-digital public displays and act as a facilitator or ‘spark’ to affect people’s engagement with public visualisations and to foster social interaction among people. As robots are increasingly being tested in real-world urban contexts — mainly to complete mundane tasks — our aim was to investigate their potential for triggering urban reflection, “getting lost” in cities and “slowing down”.

This article is a summary of a full paper submission accepted to the ACM CHI Conference on Human Factors in Computing Systems (CHI’20) with the title “Stop and Smell the Chalk Flowers: A Robotic Probe for Investigating Urban Interaction with Physicalised Displays”. The conference was supposed to be held between April 25–30, 2020 in Honolulu, Hawai’i, USA, but was cancelled due to the current Covid-19 pandemic. The paper is published in the ACM library (https://dl.acm.org/doi/abs/10.1145/3313831.3376676), and a full-text is available here.

Pervasive displays in the city

Our study builds on and contributes to the field of pervasive displays, which has been extensively studied by the CHI community — as a field that takes computing into the urban space through digital screens that can be either interactive or non-interactive. Compared to smartphones, pervasive displays enable a push-based distribution of content that is addressed to the public instead of individuals. However, several works reported that passers-by tend to ignore digital screens. Therefore, researchers investigated how to overcome so-called display blindness, for example, through adding layers of interactivity or aiming for the design of more relevant content.

Figure 2: Manually updating non-digital physical displays by a research team was reported to drive more engagement around public visualisations.

Several studies also investigated and documented the use of non-digital displays, for example, through using chalk spray stencils to display urban visualisations on the pavement or deploying chalkboard-like signage for comparative energy feedback on the façades of residential houses (Figure 2). Based on their studies, the authors outlined several qualities of non-digital public visualisations: for example, they reported that textures and materiality, as well as the horizontal position of content on the pavement, attracted passer-by to approach (and touch) the visualisations. Further, the transient nature of the visualisations made people aware of their finite lifetime, resulting in additional appreciation of the content. The manual update process carried out by a research team created additional engagement between residents and the researchers acting as facilitators. Yet, although those studies suggest that non-digital physicalised displays can address some of the socio-technical pitfalls related to digital urban displays, their hyperlocal scale and impact remain unaddressed limitations.

Design considerations

From the outset, the design goal was to create a robotic device which could render digital drawings in a physicalised form, deeply integrated into the existing urban environment. One requirement was to design a ‘plug-in system’ that could be deployed “anywhere” in public space, in and out, without the need for additional infrastructural support, such as a canvas or a stationary power source. As sidewalks and public plazas are ubiquitous in cities, publicly owned and used as a stage for social interactions, we decided for a self-moving, autonomously powered platform which uses the ground as a large canvas.

Figure 3. Early renderings of Woodie.

Shape. In line with our goal of enticing curiosity by depriving Woodie from any obvious association with preconceptions about how a robot should look like, we decided early on not to give it anthropomorphic features (Figure 3). Instead, we opted for a circular body, thus allowing the robot to move in any direction without the constraints of having to reposition its “face”.

Size. Woodie should be large enough to be noticed by passersby, yet small enough not to become an obstacle to them, and not to obstruct visibility of its own drawings.

Speed. Slowness emerged as an important feature for Woodie, as it should move sufficiently slow to allow for thoughtful appreciation by the public, as well as not to compromise the free movement of pedestrians in the public space.

Figure 4. Two different drawing style explorations (with the actual vector graphics in purple): geometric flower (left), sketchy flower (right).

Information visualisation. The information visualised through the robot’s drawings — representing an instance of the physicalised display — had to be aligned with the environment and its physical and temporal context. Given that Woodie was located in a laneway, we aimed to use visualisations for activating the space, implementing digital placemaking principles to connect people with the space and with each other. As we deployed Woodie in the context of a public light festival, we aimed to align the visualisations with the theme of the festival, which was “love, peace and harmony”. These considerations led us to the use of simple shapes, such as flowers and hearts. An important aspect at this prototyping stage was not only to decide for the “right” type of content, but also to explore the characteristic style of the drawings. After several tests drawing on various grounds, we realised that highly geometric vector graphics convey the impression that the drawings are imperfect when “rendered” on rough terrain, while less geometric, hand-sketched drawing styles worked well with Woodie’s limited drawing accuracy (Figure 4).

Information communication. In addition to creating a public display through drawing on the ground, Woodie should also have communicative features itself. Following recommendations from research on autonomous vehicles, suggesting the use of visual signals for communicating a vehicle’s intent to people around the vehicle, Woodie should be capable of visually representing its internal mode. We chose a low-resolution LED lighting display solution given their established aesthetic qualities.

Deploying Woodie in-the-wild

We deployed Woodie over the period of three weeks, during evening hours, in a quiet laneway situated within a major business and residential district. Due to the slow movement, Woodie was usually not drawing more than four individual drawings per hour.