Study of noise readings in infrared sensors and their effect in the Khepera Miniature Robot

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Study of noise readings in infrared sensors and
their effect in the Khepera Miniature Robots
performance

• Saúl J. Vega Daisy A. Ortiz
• Advisor Raúl E. Torres, Ph.D., P.E.

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Background

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

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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

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Problem Statement

• Avoid negative effect of fluorescent lamps on
  infrared sensory readings

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Objectives

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

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Methodology

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

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Our StarMr. Khepera
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Anatomy of the Khepera
Microprocessor
IR-Sensors
Wheels DC-Motors
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Insights of Our Hero
Microprocessor
IR-Sensors
Wheels DC-Motors
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Simplified Braitenberg Algorithm
Move Forward
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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

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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

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Conclusions

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

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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

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Questions?