The Development of a Low-Cost and Robust Autonomous Robot Colony Using LEGO Mindstorms

Abstract

The late twentieth century marked the birth of urban search and rescue robots. The act of rescuing victims from collapsed or damaged buildings is extremely dangerous for the humans involved. After the attacks on the World Trade Center, researchers recognized the need for small robots with limited capabilities to be used in conjunction with more advanced robots for urban search and rescue. This research has developed a low-cost, autonomous robot colony with limited sensor capabilities using the LEGO® Mindstorms™ development platform. The study of this colony will provide insight into the group behavior of a marsupial robot colony used for urban search and rescue.

A microphone sensor was developed to facilitate communication among the robot agents that comprise the colony. The incoming analog signal was amplified using a standard non-inverting operational amplifier configuration. This amplified signal was input into a tone detection circuit. This circuit was designed to provide a digital output to the LEGO® robot if a single tone of a specific frequency was detected. Other frequency tones have no effect on the circuit. Using this sensor, the robots could be controlled with different frequency tones.

The task undertaken by the robots was a shepherding mission. The goal of the sheepdog robot was to herd the sheep robot into a pen located at a fixed location. A helper dog robot was added to assist the sheepdog when needed. The interaction, as well as communication, between the sheepdog and helper dog was studied.