The ‘dozer Mobots installation, is a reactive artwork, concerned with subjects of communication and control within societies. It consists of five computer controlled robot bulldozers (‘dozers), moving over, and hence transforming, sculpting a terrain of earth three meters square. Users are able to subtly, influence the installation by way of a mouse click on a two dimensional density map representation of the terrain, contained within a controlling computer.
Users are able to subtly, influence the installation by way of a mouse click on a two dimensional density map representation of the terrain, contained within a controlling computer. The image above left, is an example of how this may look, the light areas represent peaks, the dark troughs as in the image below left.
The dozers traverse the terrain randomly, being commanded to lower their snow plough like blades when within a dark sector. In this way the earth is gradually changed to an imperfect three dimensional representation of the density map stored within the controlling computer. Above right is an imagined three dimensional rendering of the kind of landscape produced by the ‘dozers, from the image on the left, a video feed of what is actually happening within the installation is displayed on screen.
The five ‘dozers are battery powered, tracked robots 350 mm long. One geared motor powers each track to enable turning, an R/C servo lifts and lowers the blade. On board is an infra-red receiver, streaming data from the controlling computer to a ‘basic stamp’ (small PIC based single board computer); in turn controlling the motors, according to it’s ‘basic’ code. Each mobot has a lamp to enable it’s identification by the computer, via a video camera.
A couple of tons of earth is distributed within an area 3 meters square. Ceiling mounted centrally above this is an infra-red LED, transmitting modulated pulses of infra red to the mobots. This is driven from the controlling computer’s serial port. Each mobot has a code number and only responds to byte code instructions after transmission of it’s code number. A video camera will be positioned next to the LED, relaying images back to the computer via a video grabbing board.
Code written in ‘C’ receives and process data from the video camera, images are processed and co-ordinates of each mobot determined. According to the mobots position on a light or dark area it will be commanded to raise or lower it’s blade. Direction of travel of each mobot is calculated by comparing it’s present co-ordinates with the pervious three, if it is moving off the installation area, a turn command is sent. Collision avoidance is also calculated in this way. Grabbed video images, with the mobots calculated vectors are displayed on the monitor alongside the density map.