Rafael Lozano-Hemmer
Antimodular Research
2004, 2024
External Project Link
Double Standards is an artwork by Rafael Lozano-Hemmer exploring power dynamics in a room. A leather military belt is suspended with fishing line in mid-air from a rotational arm in the ceiling. The belt is programmed so that the buckle rotates to always face a particular viewer in space, which is surveiled via overhead camera. Originally conceived and shown in 2004, the piece has undergone numerous iterations and technical updates.
My task was to rebuild and improve the piece so that it could be shown -- for the second time in its career -- at Bitforms Gallery in New York. At the beginning of this process I was handed a few pieces of a non-functional version of the artwork and directed to explore motion control techniques that would allow the belt to move faster without oscillating or wobbling in its trajectory.
To accomplish this I enlisted the help of a researcher in the Czech Republic who is an expert in oscillation dampening for heavy loads suspended from cranes. We collaborated on a resource constrained version of an algorithm called an input shaper that allowed the rotational arm of the artwork to correct its motion for to different types of oscillation -- pendular and rotational.
Part of the fun in this collaboration was keeping such an intensive algorithm in its most basic form. One version of this artwork contains up to 50 networked belts that all move in sync, so I was challenged to create design parameters that would allow us to scale our final solution at a reasonable cost.
The final solution I created is a light-weight motion control library written in C++ with a configuration, calibration, and viewer tracking interface written in Python. Because every installation of this artwork is slightly different depending on the size of the gallery space, there is no ``one size fits all'' solution for such a complex motion control problem.
The lightweight interface runs in the browser and integrates all the calibration features with a computer vision application for tracking viewers from an overhead camera feed in real-time. This solution enables non-technical installers to calibrate and check the piece while satisfying budgetary and functional constraints. Soon we will begin scaling the solution to work for all 50 belts!