study of noise readings in infrared sensors and their effect in the khepera miniature robot’s...
TRANSCRIPT
Study of noise readings in infrared sensors and their effect
in the Khepera Miniature Robot’s performance
Saúl J. Vega Daisy 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
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
Simplified Braitenberg Algorithm
Turn Right
Obstacle onLeft side?
No
Yes
Obstacle onRight side?
Turn Left
Yes
NoMove Forward
No Obstacle onBack?
EndYes
No filter in Darkness
0
200
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600
800
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1200
1 23
45
67
89
111
133
155
177
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287
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331
353
n
IR-v
alu
es
No filter in Light
0200400600800
10001200
1
78
155
232
309
386
463
540
617
694
771
848
925
1002
n
IR-v
alu
es
Averaging in Light
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IR v
alu
es
IIR filter in Light
0200400600800
10001200
1 23
45
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89
111
133
155
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n
IR v
alu
es
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