1. Component-Based Agent Frameworks And SoccerBeans
12/4/2018
Component-Based Agent Frameworks And SoccerBeans
Hrishikesh J. Goradia
CSCE 782 Fall 2003
University of South Carolina
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

2. Component-Based Agent Framework
Component-Based Software Engineering Techniques
Current Agent Framework Development Techniques
Component-Based Agent Framework
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

3. Component-Based Agent Framework
Applications
Domain specific Agent Framework
Development Environment
Component Based Agent Framework
CBAF specifications
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

4. Component-Based Agent Framework
Applications
Domain specific Agent Framework
Development Environment
Component Based Agent Framework
CBAF specifications
Components encapsulate the underlying complexities of the framework
Designing MAS using CBAF is simple
CBAF is domain-specific
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

5. CSCE 782 – CBAF & SoccerBeans
CBAF Specifications
Agent framework must be designed as a set of independent, self-contained, highly specialized components.
Commonalities of various applications in a domain must be discovered and developed as domain-specific components in the framework.
A component must be interface-centric and architecture-centric.
Components must be designed such that each performs a unique, singular function. Conversely, every function to be performed by an agent in a domain application must be defined as a component in the framework.
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

6. CSCE 782 – CBAF & SoccerBeans
CBAF Specifications
Framework designers must strive for the development of “context-free” components.
The agent framework must provide a look-up service for the agents. Message transport must be facilitated through event triggering.
The framework must facilitate the integration of its components to create different agent plans (also called as activities). It must also provide a way to compose these activities with the individual agents.
Agent framework must include the following types of components:
Agent component(s)
Activity component(s)
Decision components
Behavior components
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

7. Sample CBAF Implementation (RoboCup domain)
Behavior Components
kick
catch
dash
move
Decision Components
spatial
AND
location OR
Activity 1
Activity 2
Activity n
. . .
Pool of Activities
1 n
Agent component
Activity component
Individual Agent
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

8. Sample CBAF Implementation (RoboCup domain)
Behavior Components
kick
catch
dash
move
Decision Components
spatial
AND
location OR
Activity 1
Activity 2
Activity n
. . .
Pool of Activities
1 n
Agent component
Activity component
Individual Agent
Behavior components
A behavior component must represent an agent’s action
Each rule set in a plan must be mapped to a behavior component
The framework must provide every possible atomic action for an agent in the particular domain as a behavior component
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

9. Sample CBAF Implementation (RoboCup domain)
Behavior Components
kick
catch
dash
move
Decision Components
spatial
AND
location OR
Activity 1
Activity 2
Activity n
. . .
Pool of Activities
1 n
Agent component
Activity component
Individual Agent
Decision components
Represents a rule used during plan generation for an agent
The framework must facilitate the combining of various decision components to define new rules
The framework must include all the decision components to accommodate the creation of any rule for a plan
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

10. Sample CBAF Implementation (RoboCup domain)
Behavior Components
kick
catch
dash
move
Decision Components
spatial
AND
location OR
Activity 1
Activity 2
Activity n
. . .
Pool of Activities
1 n
Agent component
Activity component
Individual Agent
Activity component(s)
Agent plans are generated as a concatenation of rules rooted by an Activity component
Interface between an agent component and it’s plans
Fully support the agent component capabilities.
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

11. Sample CBAF Implementation (RoboCup domain)
Behavior Components
kick
catch
dash
move
Decision Components
spatial
AND
location OR
Activity 1
Activity 2
Activity n
. . .
Pool of Activities
1 n
Agent component
Activity component
Individual Agent
Agent component(s)
Represents an individual agent in the MAS
Knows how to locate and communicate with other agents in the system.
Defines the scheduling mechanism for handling its plans.
A user has to associate the agent component with plans to complete the agent design
Different agent architectures are represented as separate agent components in the framework
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

12. Challenges for CBAF Design
Which components should we develop in the agent framework for a given domain?
The components have to be functionally independent, but they also rely on each other for accomplishing their tasks and hence should be interactive and cohesive. How do we achieve that?
How do we achieve component integration to create new components?
How do we deploy the whole system with multiple agents?
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

13. CSCE 782 – CBAF & SoccerBeans
RoboCup Domain
Simulated soccer
Based on a client/server architecture
Provides an environment that is
Complex
Distributed
Real-time
Collaborative
Adversarial
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

14. Domain Analysis for CBAF Design (SoccerBeans)
Which components should we develop in the agent framework for a given domain?
All agents created as beans, have a scheduling mechanism that supports both BDI and Subsumption architectures
Agent component: PlayerFoundation bean
Only one architecture to be supported
Activity component: Activity bean
Decision criteria in different agent plans for various soccer teams
Decision components: DBallDistance, DSelfPosition, DClosePlayers, etc.
All agent actions
Behavior components: BDash, BDribble, BShoot, BMove, BTurn, etc.
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

15. Domain Analysis for CBAF Design (SoccerBeans)
The components have to be functionally independent, but they also rely on each other for accomplishing their tasks and hence should be interactive and cohesive. How do we achieve that?
Java’s Delegation Event Model for event handling
Communication between adjacent components only
ActivityEvent event
Agent – Activity component communication
FunctionalityEvent event
Activity – Decision component communication
Activity – Behavior component communication
Decision – Behavior component communication
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

16. Domain Analysis for CBAF Design (SoccerBeans)
How do we achieve component integration to create new components?
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

17. Domain Analysis for CBAF Design (SoccerBeans)
How do we deploy the whole system with multiple agents?
Sun’s Bean Development Kit (BDK) provides a runtime environment for deploying live beans
Distributed programming issues handled by UDP sockets
One JVM per agent
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

18. SoccerBeans – CBAF Implementation for RoboCup Domain
Uses the Sun’s JavaBeans technology
Agent component supports decision-making based on BDI and Subsumption architectures
SoccerBeans components -
Agent component
PlayerFoundation bean
Activity component
Activity bean
Decision components
DBallDistance, DBallPosition, DPlayerPosition, etc.
Behavior components
BDash, BKick, BTurn, BMove, etc.
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

19. Agent and Activity Components for SoccerBeans
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

20. Decision Components for SoccerBeans
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

21. Decision Components for SoccerBeans
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

22. Behavior Components for SoccerBeans
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

23. Behavior Components for SoccerBeans
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

24. CSCE 782 – CBAF & SoccerBeans
A Sample Team
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

25. CSCE 782 – CBAF & SoccerBeans
Common Activities
All 11 players share the Observe and StartPlay activities
Observe incorporates the new sensory information from the server into the player’s world model
StartPlay is for relocating the player to its starting position before kickoff and after a goal
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

26. CSCE 782 – CBAF & SoccerBeans
Goalie
Goalie activities
Observe (5)
StartPlay (8)
Catch (10)
Pass (11)
GoalKick (5)
GotoPosition (9)
Used 50 components to create the goalie
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

27. CSCE 782 – CBAF & SoccerBeans
Goalie Activities
Catch activity for allowing the goalie to catch the ball
Pass allows the goalie to move to a corner on the penalty box after catching the ball, or kick the ball away
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

28. CSCE 782 – CBAF & SoccerBeans
Goalie Activities
GoalKick handles the “goal_kick_*” play mode
GotoPosition positions the goalie to the most appropriate position, based on the ball’s current position
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

29. CSCE 782 – CBAF & SoccerBeans
Defenders
Defender activities
Observe (5)
StartPlay (8)
Pass (8)
GotoPosition (25)
Used 47 components to create each defender
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

30. CSCE 782 – CBAF & SoccerBeans
Defender Activities
Defenders simply shoot the ball away towards the opponent’s half whenever possible through the Pass activity
GotoPosition activity
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

31. Defensive Midfielders
Defensive midfielder activities
Observe (5)
StartPlay (8)
Dribble (6)
Pass (9)
GotoPosition (21)
Used 50 components to create each defensive midfielder
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

32. Defensive Midfielder Activities
Midfielders dribble the ball whenever possible
Pass the ball if dribble is inappropriate
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

33. Defensive Midfielder Activities
GotoPosition activity
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

34. CSCE 782 – CBAF & SoccerBeans
Offensive Players
Offensive player activities
Observe (5)
StartPlay (8)
Dribble (7)
Pass (8)
GotoPosition (13,13,11,15,15)
Used an average of 42 components to create each offensive player
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

35. Offensive Player Activities
Dribble activity
Pass activity
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

36. Offensive Midfielder Activities
GotoPosition activity for offensive midfielders
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

37. Offensive Central Midfielder Activities
GotoPosition activity for offensive midfielders
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

38. CSCE 782 – CBAF & SoccerBeans
Forwards’ Activities
GotoPosition activity for forwards
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

39. CSCE 782 – CBAF & SoccerBeans
Testing and Results
Gamecocks beat Chikomalos 18-0!
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

40. Improving SoccerBeans
SoccerBeans has a lot of scope for improvement
Decision beans concerning locations of other agents on the field
Inter-agent communication – “say” messages
Better dashing – use of “turn_neck” instead of “turn” wherever possible
Better kicking – tighter dribbling, better computation of “kick_power”
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

41. CSCE 782 – CBAF & SoccerBeans
Developing New Beans
Beans are just special Java classes!
Implement Serializable class
Define get/set accessor methods for its properties
All decision and behavior beans have similar structures
Differ only in their instance variables and implementations of decide() or behave() methods
Online references:
December 4, 2018
CSCE 782 – CBAF & SoccerBeans

42. Developing New Beans in SoccerBeans
Write the bean code
MyBean.java and MyBeanBeanInfo.java files
Save these files in the $PACKAGE_HOME/soccerbeans folder, $PACKAGE_HOME is where the soccerbeans package is extracted
Compile the complete package with the bean
From $PACKAGE_HOME, say
javac soccerbeans/*.java regexp/*.java
Update the manifest file
Add the following to the soccerbeans.mft file
Name: MyBean.class
Java-Bean: True
Update the soccerbeans package
jar cfm soccerbeans.jar soccerbeans.mft soccerbeans/*.class regexp/*.class
December 4, 2018
CSCE 782 – CBAF & SoccerBeans