[ VOILES | SAILS ] is an art/science/technologie research-creation platform initiated by Nicolas Reeves, a professor and researcher-creator at the design school of UQAM. It was born from professor Reeves' will to evoke the age-old myth of an architecture freed from the law of gravity by the mean of a contemporary sculpture. Many challenges had to be solved in order to achieve this result, and many skills and expertises were required. Standing at the crossroad between art, architecture and science, the [ VOILES | SAILS ] project aims to bring together researchers from the artistic and scientific domains to collaborate.

Considering that the load of a cube includes the structure (about 2500 g), the polyurethane films (about 1500 g), the CPU, the motor controllers, the sensors, the wireless card, the batteries, eight to twelve motors and their polycarbonate ducts, a camera and dozens of meters of wires and cables, the optimisation of each element's weigth-to-efficiency ratio must be very carefully studied.

Several design constraints had to be considered:

1. The necessity to obtain a perfect cube, with straight edges and flat faces. It relates to the intention of creating perfectly geometrical flying shapes, but it is also induced by the fact that the cubes need to assemble while flying. If the edges are not perfectly straight, or if the faces become convex the cubes will not assemble properly.
2. The self-assembling properties. When two cubes connect to each other, they must still be able to use their motors to move in space. The thrusts of the motors of two connected cubes must add up in order to provide enough power to move them all. This led to the decision to place the ducted fans at the midpoint of each edge, and to guide the air streams towards the corners of the cubes with thin polycarbonate tubes.
3. The location of the sensors. The cube is by no way an optimal shape when it comes to sensory aptitudes, especially with large cubes (edge 160 cm or more). Obstacle avoidance would ideally require 24 sensors (one for each axis on each edge), which is hard to implement for reasons of cost, payload and energy requirements. The optimal sensor configuration is continuously being studied and updated for each project's needs.

After many design iterations and prototypes the structure reaches a stable stage with the last aerobots, christened t225c (edge length of 225 cm), the Tryphon. Its exosqueletton is made of twelve triangular trusses of carbon fiber rods and tubes assembled together by rapid prototyping joints.

The mechatronic of the SAILS robots was developed in order to easily accept various sensors configuration. All the components are connected to an I2C communication bus managed by the central ultralight, Linux-based computer. Until now ultra-sounds sensors, light sensors, compass, altimeter have been tested and used for performances and demos. A video camera and accelerometer will be installed onboard in the very next phases. The sensors configuration can be quickly modified, thanks to quick-connect hubs.

The embedded control software has two mode: autonomous or teleoperated. This last mode allows the user to command position (through a USB numeric pad) which the controller then tries to stabilize. The autonomous mode is currently based on reactive behaviors. The two first automous algorithms were to stabilize itself according to a desired distance from a wall or a floor, and avoid obstacles while moving around. They use data collected from 12 ultrasounds sensors that have a 6-meters detection range. Many others specific behaviors were developed to trigger reactions to the robot's environment.

The SAILS prototypes have been shown during major art events in several countries: Canada (Quebec Museum of Civilization), Belgium (Antwerpen Museum of Fashion), France (Grand Palais, Paris), Russia (Moscow Winzavod Center) and Czech Republic (Industrial Palace, Prague), among others. They also participated in several educational events.

Future developments involve the enhancement of the robustness of the aerobots for theatrical performances and public events; revision of the software to ensure maximal reliability during interactions with actors, so that planned interactions can be faithfully repeated in every performance; implementation of in-board camera/acceloremeter based control in order to give the aerobots a better knowledge of their pseudo-absolute position and microphones to open new human interaction possibilities.

[ VOILES | SAILS ] is managed and mainly funded by the interuniversitary research-creation center in numerical arts HexagramCIAM, UQAM and the different Canadians and Quebec Arts Councils.

More detailed information about the project, its origin and last exhibitions can be found on the project's official website.