the need of unmanned systems ddd (dull, dirty, dangerous ) also –distant remote diagnoses, first...
Post on 22-Dec-2015
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The Need of Unmanned Systems
• DDD (Dull, Dirty, Dangerous)• Also
– Distant • Remote diagnoses,
• First Aid,
• Tele-Surgery, etc
– Micro and nano devices
Is well recognized to perform tasks that are:
Telemedicine Consultation
Tele - Surgery
Tele Virutal Consultation
• (Manual) Remote Control:– needs line of sight (LOS) between HO and machine.
– all control loops closed through the HO.
– needs full attention from the HO.
• Teleoperated: – no need of LOS– few sensors to enable HO decision making process
– needs full attention from the HO.
• Human Supervisory Control: – sensors used to enable autonomous decisions.
– only partial attention from the HO is needed.
• Autonomous tasks:– tasks performed based on sensory information.
– HO monitors and communicates information about goals, constraints, plans, etc.
Mixed Initiative Control Methods.
The spectrum of control modes.
Solid line= major loops are closed through computer, minor loops through human.
• traded control: control is or at operator or at the autonomous sub-system.
• shared control: the instructions given by HO and by the robot are combined.
• strict supervisory control: the HO instructs the robot, then observes its autonomous actions.
A telerobot can use:
System Decomposition
• The traditional approach to control was: the Sense-Plan-Act (SPA) approach
inherently sequential
This produces deliberative architectures. Behavior Based Architectures produce
inherently parallel systems.
Make the machine an agent in human operator’s service.
What is a behavior?
• An individual behavior is a stimulus/ response pair for a given environmental setting that is modulated by attention and determined by intention.
• Behaviors serve as the basic building blocks for robotic actions.
Attention: prioritizes tasks and focuses sensory resources and is determined by the current environmental context.
Intention: determines which set of behaviors should be active based on the robotic agent’s internal goals and objectives.
Apparent or emergent behavior: the global behavior of the robot as a consequence of the interaction of the active individual behaviors.
Environment
Sense Asset
Learn
PlanAct
Agent
• An agency relationship is present whenever one party (the principle) depends on another party (the agent) to undertake some task on the principle’s behalf.
• An agent is an entity which can be viewed as perceiving its environment through sensors and acting upon that environment through effectors.
Assembling Behaviors.
• Systems are constructed from multiple behaviors.
• Emergent behavior implies a holistic (attention to the “whole”) capability where the sum is considerably greater than its parts.
• Emergence is “the appearance of novel properties in whole systems”.
• Intelligence emerges from the interaction of the components of the system.
• Coordination functions are algorithms used to assemble behaviors.– Conflict can result when two or more behaviors are active, each
with its own independent response.
The Agent
• An agent is a computer system capable of autonomous action in some environments.
• A general way in which the term agent is used is to denote a hardware or software-based computer system that enjoys the following properties: – autonomy: agents operate without the direct intervention of
humans or others, and have some kind of control over their actions and internal state;
– social ability: agents interact with other agents (and possibly humans) via some kind of agent-communication language;
– reactivity: agents perceive their environment, (which may be the physical world, a user via a graphical user interface, or a collection of other agents), and respond in a timely fashion to changes that occur in it;
– pro-activeness: agents do not simply act in response to their environment; they are able to exhibit goal-directed behavior by taking the initiative.
Agents and Behaviors
• Behavior is defined as the way how we/people observe the system/robot acts/behaves.
• The robot system is NOT aware of what we know about it.– What makes the system act as we observe is its
software.
• Agents are implementing behaviors.
Agent control loop
• agent starts in some initial internal state i0 .
• observes its environment state e, and generates a percept see(e).
• internal state of the agent is then updated via next function, becoming next_(i0, see(e)).
• the action selected by agent is action (next(i0, see(e))))
This action is then performed.
• Goto (2).
RCSEmbeds a hierarchy of agents within a hierarchy of organizational units: Intelligent Nodes or RCS_Nodes.
RCS_Node
Value Judgment
Sensory Processing
World Modeling
Behavior Generation
Knowledge Database
Update Plan
StatePredicted Input
Observed Input
Perceived Objects &
Events
Commanded Actions
(Subgoals)
Commanded Task (Goal)Plan
EvaluationPla
n R
esul
tsS
ituation E
valuation
Sequential and Parallel Task Decompositions.
• Sense Plan Architectures use a functional decomposition, i.e., – the systems consist of sequential modules achieving independent
functions (sense-world, generate-plan, translate-plan-into-actions).
• RCS architecture advocates decomposition along a temporal dimension.
• The Reactive Architectures in general, use a task-oriented decomposition, i.e.,
– the systems consist of parallel (concurrently executed) modules achieving specific tasks (avoid-obstacle, follow-wall, etc.)
– implemented with situated automata model.
• It recognizes a fundamental relationship an agent has as a participant within its environment.• Principles of reactivity are hybridized in circuits, which corresponds with robots goals and intentions.