Study of noise readings in infrared sensors and their effect in the Khepera Miniature Robot’s performance Saúl J. VegaDaisy A. Ortiz Advisor: Raúl E. Torres, Ph.D., P.E.

Background Robots –Management of hazardous waste –Moving of heavy equipment –Ocean and space exploration –Fire extinguishing Artificial Intelligence –Knowledge-based –Behavior-based

Background (cont.) Behavior-based Artificial Intelligence –Subsumption Architecture (SA) Build behaviors from smaller sub-behaviors SA rely heavily on sensory input –Noise cause disturbance in robot operation

Problem Statement Avoid negative effect of fluorescent lamps on infrared sensory readings Oh! No!

Objectives Determine the effect of noisy readings on robot performance Determine the effect of filtered sensory on robot performance

Methodology Review of literature Simulation study Hardware implementation –Real Khepera used in testing Filters design Testing-platform development –Braitenberg vehicle algorithm Comparison of results

Our Star: Mr. Khepera

Anatomy of the Khepera Microprocessor IR-Sensors Wheels & DC-Motors

Insights of Our Hero MicroprocessorIR-SensorsWheels & DC-Motors

Simplified Braitenberg Algorithm Turn Right Obstacle on Left side? No Yes Obstacle on Right side? Turn Left Yes No Move Forward No Obstacle on Back? End Yes

Results On darkness –Slow filter response when approaching obstacle –Even slower when moving away from obstacle On light –Acceptable filter response time when approaching obstacle –Acceptable filter response time when moving away from obstacle –Noisy readings greatly reduced

Results (cont.) Satisfactory performance of Braitenberg algorithm without filtered readings on darkness Problems using filters with Braitenberg algorithm –Robot slow to react to filtered sensory readings

Conclusions Fluorescent light noise cause serious effects on Khepera’s performance Digital filters proved to be useful in reducing noise in sensory readings Filters performance are greatly affected by levels of ambient light

Future Works Braitenberg algorithm modified to allows detection of ambient light –Activate filters on high levels of ambient light –Disable filters on low-light conditions Develop user-friendly program for testing algorithms and filters

Questions?