Semester of Graduation

Spring 2021


Master of Science in Mechanical Engineering (MSME)


Mechanical Engineering

Document Type



This study presents an onboard sensor system for determining the relative positions of mobile robots, which is used in decentralized distance-based formation controllers for multi-agent systems. This sensor system uses infrared photodiodes and LEDs; its effective use requires coordination between the emitting and detecting robots. A technique is introduced for calculating the relative positions based on photodiode readings, and an automated calibration system is designed for future maintenance. By measuring the relative positions of their neighbors, each robot is capable of running an onboard formation controller, which is independent of both a centralized controller and a global positioning-like system (e.g., GPS-denied environments). This independence is referred to as decentralization. This was demonstrated with three different formation acquisition experiments, which were compared to equivalent experiments using a global positioning system and a centralized control station designed in prior studies. The centralized and decentralized experiments resulted in similar formation outcomes, but the steady-state error for the decentralized system increased. This result was an expected consequence of the uncertainty in decentralized localization measurements.

Committee Chair

Marcio de Queiroz