1. Introduction to Behavior- Based Robotics Based on the book Behavior- Based Robotics by Ronald C. Arkin

2. What is a Robot? A robot is a re-programmable, multi- functional, manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. A robot is a re-programmable, multi- functional, manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. Robotics is the intelligent connection of perception to action. Robotics is the intelligent connection of perception to action.

3. What is a Robot? (cont.) An intelligent robot is a machine able to extract information from its environment and use knowledge about its world to move safely in a meaningful and purposive manner. An intelligent robot is a machine able to extract information from its environment and use knowledge about its world to move safely in a meaningful and purposive manner.

4. Related Areas Cybernetics Cybernetics Artificial intelligence Artificial intelligence Robotics Robotics

5. Spectrum of Robot Control Deliberative/Hierarchical control Deliberative/Hierarchical control Requires relatively complete knowledge about the world. Requires relatively complete knowledge about the world. Requires strong assumptions about this world model. Requires strong assumptions about this world model. Hierarchical in structure with a clear identifiable subdivision of functionality. Hierarchical in structure with a clear identifiable subdivision of functionality. Communication and control occurs in a predictable and predetermined manner. Communication and control occurs in a predictable and predetermined manner. Higher levels in the hierarchy provide subgoals for lower subordinate levels. Higher levels in the hierarchy provide subgoals for lower subordinate levels. Planning scope changes during descent in the hierarchy. Planning scope changes during descent in the hierarchy.

6. Spectrum of Robot Control (cont) Reactive control Reactive control Reactive control is a technique for tightly coupling perception and action, typically in the context of motor behaviors, to produce timely robotic response in dynamic and unstructured worlds. Reactive control is a technique for tightly coupling perception and action, typically in the context of motor behaviors, to produce timely robotic response in dynamic and unstructured worlds. Behaviors serve as the basic building blocks for robotic actions. Behaviors serve as the basic building blocks for robotic actions. Use of explicit abstract representational knowledge is avoided in the generation of a response. Use of explicit abstract representational knowledge is avoided in the generation of a response. Animal models of behavior often serve as a basis. Animal models of behavior often serve as a basis. Reactive systems are inherently modular from a software design perspective. Reactive systems are inherently modular from a software design perspective.

7. Design Paradigms for Building Behavior-Based Systems Ethologically guided/constrained design Ethologically guided/constrained design Situated activity-based design Situated activity-based design Experimentally driven design Experimentally driven design

8. Expressions of Behaviors Stimulus-response (SR) diagrams Stimulus-response (SR) diagrams Functional notation Functional notation b(s) = r Finite state acceptor (FSA) diagrams Finite state acceptor (FSA) diagrams Behavior ResponseStimulus

9. Expressions of Behaviors (cont) A Navigational Example A Navigational Example Consider a student going from one classroom to another. The following kinds of things are involved. Getting to the destination from current location Getting to the destination from current location Not bumping into anything along the way Not bumping into anything along the way Skillfully negotiating the way around other students Skillfully negotiating the way around other students Observing cultural customs Observing cultural customs Coping with change and doing whatever else is necessary Coping with change and doing whatever else is necessary

10. Behavior Encoding Mapping from the stimulus plane to the motor plane. Mapping from the stimulus plane to the motor plane. A behavior can be expressed as a triple (S, R, β) where S denotes the domain of all interpretable stimuli, R denotes the range of possible responses, and βdenotes the mappingβ:S->R. A behavior can be expressed as a triple (S, R, β) where S denotes the domain of all interpretable stimuli, R denotes the range of possible responses, and βdenotes the mappingβ:S->R. Discrete encoding Discrete encoding Continuous functional encoding Continuous functional encoding

11. Assembling Behaviors Behavioral coordination Behavioral coordination Competitive methods Competitive methods Cooperative methods Cooperative methods

12. Behavior-Based Architectures Definition Definition Robot architecture is the discipline devoted to the design of highly specific and individual robots from a collection of common software building blocks.

13. Behavior-Based Architectures (cont) Evaluation Criteria Evaluation Criteria Supporting for parallelism Supporting for parallelism Hardware targetability Hardware targetability Niche targetability Niche targetability Support for modularity Support for modularity Robustness Robustness Timeliness in development Timeliness in development Run time flexibility Run time flexibility Performance effectiveness Performance effectiveness

14. Behavior-Based Architectures (cont) A foraging example A foraging example The tasks consists of a robot ’ s moving away from a home base area looking for attractor objects. Wander Wander Acquire Acquire Retrieve Retrieve

15. Behavior-Based Architectures (cont) Subsumption architecture (Brooks) Subsumption architecture (Brooks) AFSM model AFSM model It is a layered architecture that uses arbitration strategies and AFSM as its basis. It is a layered architecture that uses arbitration strategies and AFSM as its basis. Coordination: Inhibition and suppression Coordination: Inhibition and suppression Pros Pros Hardware retargetability Hardware retargetability Support for parallelism Support for parallelism Niche targetability Niche targetability Cons Cons Run time flexibility Run time flexibility Support for modularity Support for modularity

16. Behavior-Based Architectures (cont) Motor schemas (Arkin) Motor schemas (Arkin) A schema is the basic unit of behavior from which complex actions can be constructed; it consists of the knowledge of how to act or perceive as well as the computational process by which it is enacted. A schema is the basic unit of behavior from which complex actions can be constructed; it consists of the knowledge of how to act or perceive as well as the computational process by which it is enacted. Motor schemas are a software-oriented dynamic reactive architecture that is non- layered and cooperative. Motor schemas are a software-oriented dynamic reactive architecture that is non- layered and cooperative.

17. Behavior-Based Architectures (cont) Motor schemas (cont) Motor schemas (cont) Coordination: vector summation Coordination: vector summation Pros Pros Support for parallelism Support for parallelism Run time flexibility Run time flexibility Timeliness for development and support for modularity Timeliness for development and support for modularity Cons Cons Niche targetability Niche targetability Hardware retargetability Hardware retargetability

18. Behavior-Based Architectures (cont) Other architectures Other architectures Circuit architecture Circuit architecture Colony architecture Colony architecture Animate agent architecture Animate agent architecture Distributed architecture for mobile navigation Distributed architecture for mobile navigation Skill network architecture Skill network architecture