Maps Meanderer

Made by Kthies

A robot traces paths being walked at this Bakery Square Bridge intervention

Created: September 3rd, 2019


On either side of the bridge, a small robot hangs suspended by two wires. As a pedestrian walks below, eyes focused on the digital map in hand, the servos in the metal disk whir. The wires spool and unspool, moving the metal disk. It positions itself accordingly, hovering over the position of he bridge on the large map decal on the bridge's glass wall. As the pedestrian continues down the street, the robot on the wall follows, leaving a red line on the glass, a trace of the day's movement.

Inside the bridge, with laptop bag in hand, an office worker shuffles to the other side, incidentally stepping on a green floor tile. Outside, with the speed of a magician's trick, the robot's path starts laying down a green line instead. Catching the sudden change, the worker pauses, and turns back, making sure to intentionally step on a yellow tile. Once again, the color changes.


This project is made up of two wire-suspended robots that hang on either side of the bridge. They receive Google maps data from nearby users, and translate that data to a line on a map decal, which follows the paths people have taken throughout the day, and then erasing itself in the early hours of the morning when there's less traffic, and taking the rime to refill/replace markers if they haven't needed to be replaced before then. Inside the bridge, special red, yellow, green, and blue tiles will be installed in the flooring, which triggers the change in line color if stepped on. These will be placed somewhat sparsely and spread out, so that it's possible to randomly step on one if crossing the bridge, or intentionally hop from one to the other. In that way, the lines and their color visualize the movement both inside and outside the bridge.


As far as design requirements go, the primary input is Google Maps data, specifically the Google Maps Timeline and the estimated/accurate paths it maps. I would liken the experience inside to watching window-washers at work while inside a building, however these are leaving a mess on those windows instead of cleaning them, but the experience is still similar. While I can't speak for everyone, I enjoy those experiences. It becomes all the more relevant if the maps on both bridges aren't necessarily oriented the same way or show the same scale, improving the likelihood that the robot will be seen from a given floor on the bridge. If the audience chooses, they can engage with the robots, changing the color of the line drawn, and that would be a more detailed experience on the inside of the bridge, as from there you could actually see the marker quickly retract and redeploy, and some of the other inner working pressed against the glass. If someone wouldn't want to interact with it, they don't have to, they can just keep walking. However, it might also be interesting to take a few minutes to mess with the colors or even just watch the robots at work, like fish in an aquarium. At the end of the day, the bridge will have a mural of movement on each side, visible as colorful noise and lines from those below, and as crisper, colorful linework inside.



Grand Total - $12983

Mural - $8448

- 352 24" x 36" window decals,  $8448

Robots - $1225

  *Computing and Hardware*

- 2 RasPi 4 - $68

- 2 RasPi mini camera modules -  $20

- 2 Custom fabricated shells -  $400

- 8 3.7v 10000 mAh Lipo Batteries -  $192


*Pulley Assembly*

- 4 100ft spools 4mm aircraft-grade wire rope - $56

- 4 Masonry wedge anchor bolts -  $15

- 4 Nema 24 stepper motors -  $144

*Marker Carousel*

- 2 Nema 24 Carousel stepper motors -  $72

- 8 HS-225MG High-performance Marker lock mini servos -  $208

- 2 HS-225MG High-performance Deploy/Retract mini servos -  $52

External Computing and Hardware -  $3310

- Dell Inspiron -  $380

- Matlab Robotics System Toolbox Perpetual License -  $2150


- Extra markers/ink -  $100

- 2 iSDT D2 Intelligent LiPo charger/Discharger -  $280

- 2 Custom fabricated housing -  $400

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A robot traces paths being walked at this Bakery Square Bridge intervention