the reactive paradigm
DESCRIPTION
Introduction to Intelligent Robots. The Reactive Paradigm. Embedded System Lab Kim Jong Hwi. Chapter Objectives Define what the reactive paradigm List the characteristics of a reactive robotic system - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/1.jpg)
The Reactive Par-adigm
Embedded System Lab Kim Jong Hwi
Chonbuk National University
Introduction to Intelligent Robots
![Page 2: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/2.jpg)
Chonbuk National University
Chapter Objectives
• Define what the reactive paradigm • List the characteristics of a reactive robotic
system• Describe the two dominant methods for com-
bining behaviors in a reactive architecture: subsumption and potential field summation
• Be able to program a behavior using a poten-tial field methodology
• Be able to construct a new potential field form primitive potential fields, and sum potential fields to generate an emergent behavior
![Page 3: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/3.jpg)
Contents
Chonbuk National University 3
Reactive Paradigm - Overview Subsumption Architecture Potential Field Methodologies Pros and cons Summary
![Page 4: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/4.jpg)
Reactive Paradigm
Chonbuk National University 4
The Reactive Paradigm• emerged in the late 1980’s• grew out of dissatisfaction with the hier-
archical paradigm -summarized by Roney Brooks
![Page 5: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/5.jpg)
Reactive Paradigm
Chonbuk National University 5
The Reactive Paradigm• layered in a vertical decomposition• access to sensors and actuators indepen-
dently
![Page 6: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/6.jpg)
Reactive Paradigm
Chonbuk National University 6
Attributes of Reactive Paradigm• all actions are accomplished through
behaviors
• motor schema : algorithm for generating the pattern of action in physical actuator
• perceptual schema : algorithm for ex-tracting the percept and its strength
![Page 7: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/7.jpg)
Reactive Paradigm
Chonbuk National University 7
S-A organization
![Page 8: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/8.jpg)
Reactive Paradigm
Chonbuk National University 8
Behavior-specific sensing orga-nization in the Reactive Para-digm
![Page 9: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/9.jpg)
Reactive Paradigm
Chonbuk National University 9
Connotations of reactive behav-iors
• executes rapidly• have no memory
![Page 10: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/10.jpg)
Reactive Paradigm
Chonbuk National University 10
5 Characteristics of reactive be-haviors• Robots are situated agents operating in an
ecological niche• Behaviors serve as the basic building
blocks for robotic actions, and the overall behavior of the robot is emergent
• Only local, behavior-specific sensing is permitted
• These systems inherently follow good software design principle
• Animal models of behavior are often cited as a basis for these systems or a particu-lar behavior
![Page 11: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/11.jpg)
Reactive Paradigm
Chonbuk National University 11
Representative architectures
• Subsumption – how behaviors are com-bined
• Potential Field Methodologies – require behaviors to be implemented as potential fields and the behaviors are combined by summation of the fields
• Rule encoding, fuzzy methods, winner-take-all voting …
![Page 12: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/12.jpg)
Subsumption Architecture
Chonbuk National University 12
Subsumption architecture Rodney Brooks’s architecture the most influential of the purely Reactive Paradigm
systems
![Page 13: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/13.jpg)
Subsumption Architecture
Chonbuk National University 13
Subsumption architecture
• Modules are grouped into layers of com-petence
(low layer ~ high layer)• Modules in a higher layer can override, or
subsume, the output from behaviors in the next lower layer
• The use of internal state is avoided• A task is accomplished by activating the
appropriate layer
![Page 14: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/14.jpg)
Subsumption Architecture
Chonbuk National University 14
Example
![Page 15: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/15.jpg)
Subsumption Architecture
Chonbuk National University 15
Level 0 recast as primitive behav-iors
![Page 16: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/16.jpg)
Subsumption Architecture
Chonbuk National University 16
Level 1 : wander
![Page 17: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/17.jpg)
Subsumption Architecture
Chonbuk National University 17
Level 1 recast as primitive behav-iors
![Page 18: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/18.jpg)
Subsumption Architecture
Chonbuk National University 18
Level 2 : follow corridors
![Page 19: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/19.jpg)
Potential Fields Methodologies
Chonbuk National University 19
Potential Field• force field on the surrounding space
exerted from perceivable objects Vector
– Magnitude; real number between 0.0 and 1– Direction
![Page 20: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/20.jpg)
Potential Fields Methodologies
Chonbuk National University 20
Potential Field
![Page 21: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/21.jpg)
Potential Fields Methodologies
Chonbuk National University 21
Potential Field
![Page 22: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/22.jpg)
Potential Fields Methodologies
Chonbuk National University 22
Programming a single potential Field
![Page 23: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/23.jpg)
Potential Fields Methodologies
Chonbuk National University 23
Programming a single potential Field
![Page 24: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/24.jpg)
Potential Fields Methodologies
Chonbuk National University 24
Programming a single potential Field
![Page 25: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/25.jpg)
Potential Fields Methodologies
Chonbuk National University 25
Programming a single potential Field
![Page 26: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/26.jpg)
Potential Fields Methodologies
Chonbuk National University 26
Programming a single potential Field
![Page 27: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/27.jpg)
Potential Fields Methodologies
Chonbuk National University 27
Programming a single potential Field
![Page 28: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/28.jpg)
Potential Fields Methodologies
Chonbuk National University 28
Programming a single potential Field
![Page 29: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/29.jpg)
Potential Fields Methodologies
Chonbuk National University 29
Programming a single potential Field
![Page 30: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/30.jpg)
Potential Fields Methodologies
Chonbuk National University 30
Programming a single potential Field
![Page 31: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/31.jpg)
Pros and cons
Chonbuk National University 31
Advantages and disadvantages• Advantages
– easy to visualize over a large region of space– easier for the designer to visualize the robot’s overall
behavior– easy to combine fields, and languages such as C++– well works behaviors developed for 2D in 3D inviro-
ment• Disadvantages
– Local minima (vector with 0 magnitude)» producing vectors with a small magnitude
from random noise» NaTs (navigation templates)
![Page 32: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/32.jpg)
Summary
Chonbuk National University 32
Summary• subsumption and potential fields
appear to be largely equivalent in practice
• The ease of portability to other domains is relative to the complexity of the changes in the task and enviroment
• Neither style of architecture explicitly addresses robustness
![Page 33: The Reactive Paradigm](https://reader036.vdocuments.site/reader036/viewer/2022062520/568161d4550346895dd1d433/html5/thumbnails/33.jpg)
Chonbuk National University 33
Thank you for listening!