LEA - Slayton

< Telepresent Surveillance >

Joel Slayton CADRE Institute
San Jose State University
One Washington Square
San Jose, CA 95192 USA
Tel: (408) 924-4368
Email: joel@well.com
URL: http://surveil.sjsu.edu

Telepresent Surveillance is a computer-media installation that was on exhibit at the Krannert Art Museum in Champaign, Illinois, November 17, 1995 to January 21, 1996. Telepresent Surveillance is an experiment in automated surveillance technology. The merging of telepresence and surveillance technology creates a new form of access and participation in public spaces.

The installation involves three integrated systems: 3 autonomous robot probes, wireless video transmission and telepresent viewing via the internet. Programmed movement behaviors for each probe are activated by human presence within their defined and shared proximities. A 5 ft. diameter helium filled balloon tethered to the probe suspends a miniature CCD camera and wireless AV transmitter. Real time video output from each probe's perspective orientation and real time movement is displayed on monitors. Video output is digitally sampled and then accessed by a remote host server located at the CADRE Institute in San Jose, California. Continually updated images are incorporated into this self editing World Wide Web site for telepresent viewing.

Click here to view a movie clip.

The robot probes operate as completely autonomous surveillance devices. Each probe is programmed with interactive movement and tracking behaviors that uniquely characterize an individual personality. The robot probes act in concert with the environment, audience and one another. Individual behavior is predictable only at the systems design level. Actual behaviors are highly conditional and are derived from the interactive influences the probes experience at the site. The objective is to create a community of surveillance machine agents that permit observable 'emergent behavior' to arise.

Technical Details

The robots each have a custom designed infrared/sonar system that is used to track the humans in its working radius. The rotating head of this sensor contains a tightly focused passive infrared sensor that triggers a Polaroid ultrasonic ranging device, which has a working range of 13 inches to 30 feet. As the scanner rotates it detects a warm body via an ultrasonic ping. Connected to the rotating head is a simple positional encoder that resolves 8 angular wedges of rotation. A Basic Stamp computer is used to store range and vector information, and selected targets for observation. It then sends the appropriate vector data to the Stamp that controls the robot's movement.

The controller Stamp computer uses the vector data transmitted from the sensor to orient the robot such that the overhead video camera/transmitter is pointed more or less at the selected target. The robot is driven by 2 motorized wheels at the sides with a caster at the front and the rear. Speed and direction of the motors are controlled directly from the Stamp via PWM driven motor bridge driver chips.

Collision avoidance is accomplished with 44khz ultrasonic transmit/receive sensor pairs. There are 4 systems per robot, 2 facing forward and 2 facing back. These sensors were adapted from a surplus device intended for automobile use. In the car they had a module mounted to the mirror that would show a bar graph of the distance to the nearest object as you back up. Each dot on the bar represented 1 foot. By connecting the output of the 2nd dot on the display to the Stamp computer we have immediate warning of an impending collision from 2 feet away so that an avoidance routine can back the robot away.

Joel Slayton is Director of the CADRE Institute (Computers in Art and Design/Research and Education), a interdisciplinary academic and research program at San Jose State University. CADRE is dedicated to exploration of computers and interactive media technology. He has collaborated with various individuals, corporations and institutions to produce many large and complex performance artworks and installations which incorporate innovative forms of media technology. Joel Slayton's art works involving computers and media technology have been presented internationally.