Object-Action Complexes (OACs) are proposed as a universal representation enabling efficient planning and execution of purposeful action at all levels of a
cognitive architecture (Kruger 2009, Worgotter 2008, Geib 2006, Piater 2009). OACs combine the representational and computational
efficiency
Efficiency is the often measurable ability to avoid wasting materials, energy, efforts, money, and time in doing something or in producing a desired result. In a more general sense, it is the ability to do things well, successfully, and without ...
for purposes of search (the frame problem) of
STRIPS rules and the object- and situation-oriented concept of
affordance with the logical clarity of the
event calculus. Affordance is the relation between a situation, usually including an object of a defined type, and the actions that it allows. While affordances have mostly been analyzed in their purely perceptual aspect, the OAC concept defines them more generally as
state transition functions suited to prediction. Such functions can be used for efficient
forward chaining planning, learning, and execution of actions represented simultaneously at multiple levels in an
embodied agent
In artificial intelligence, an embodied agent, also sometimes referred to as an interface agent, is an intelligent agent that interacts with the environment through a physical body within that environment. Agents that are represented graphically ...
architecture.
The PACO+ project an Integrated Project funded by the
European Commission through its Cognition Unit under the Information Society Technologies of the sixth
Framework Programme
The Framework Programmes for Research and Technological Development, also called Framework Programmes or abbreviated FP1 to FP9, are funding programmes created by the European Union/European Commission to support and foster research in the Europea ...
(FP6), and launched on 1 February 2006, brings together an interdisciplinary research team to design and build
cognitive robots capable of developing perceptual, behavioural and cognitive categories that can be used, communicated and shared with other humans and artificial agents. In the project they hypothesize that such understanding can only be attained by embodied agents and requires the simultaneous consideration of perception and action resting on three foundational assumptions:
* Objects and Actions are inseparably intertwined in cognitive processing; that is “Object-Action Complexes” (OACs) are the building blocks of
cognition
Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...
.
* Cognition is based on reflective learning,
contextualizing and then reinterpreting OACs to learn more abstract OACs, through a grounded sensing and action cycle.
* The core measure of
effectiveness for all learned cognitive structures is: Do they increase situation reproducibility and/or reduce situational uncertainty in ways that allow the agent to achieve its goals?
Natural language grounding
The domain of
Cognitive robotics
Cognitive Robotics or Cognitive Technology is a subfield of robotics concerned with endowing a robot with intelligent behavior by providing it with a processing architecture that will allow it to learn and reason about how to behave in response t ...
tries to recognize manipulation tasks which are demonstrated by humans and other robots. In the simplest form, it's equal to a video parsing system but it can be extended with learning capabilities.
Before a robot can execute tasks, the environment has to perceived with
Robotic sensors
Robotic sensors are used to estimate a robot's condition and environment. These signals are passed to a controller to enable appropriate behavior.
Sensors in robots are based on the functions of human sensory organs. Robots require extensive info ...
. The raw data are converted into machine readable information which are enriched with semantic information. Natural language grounding (
Symbol grounding problem
In cognitive science and semantics, the symbol grounding problem concerns how it is that words ( symbols in general) get their meanings, and hence is closely related to the problem of what meaning itself really is. The problem of meaning is in ...
) is equal to convert the actions of the robot's environment into textual information.
Semantic Event Chains
[{{cite journal , doi=10.1177/0278364911410459 , year=2011 , publisher=SAGE Publications , volume=30 , number=10 , pages=1229--1249 , author=Eren Erdal Aksoy and Alexey Abramov and Johannes Dörr and Kejun Ning and Babette Dellen and Florentin Wörgötter , title=Learning the semantics of object action relations by observation , journal=The International Journal of Robotics Research, hdl=2117/14016 , hdl-access=free ] and Object-Action complex are used to store the information in a database.
Further reading
*Krüger, N., Piater, J., Wörgötter,F., Geib, Ch., Petrick, R., Steedman, M.; Ude, A., Asfour, T., Kraft, D., Omrcen, D., Hommel, B., Agostini, A., Kragic, D., Eklundh, J., Kruger, V. and Dillmann, R.(2009). A Formal Definition of Object Action Complexes and Examples at different Levels of the Process Hierarchy.
* Wörgötter, F., Agostini, A., Krüger, N., Shylo, N. and Porr, B. Cognitive agents - a procedural perspective relying on the predictability of Object-Action-Complexes (OACs). Robotics and Autonomous Systems, 2008.
* Geib, Ch., Mourao, K., Petrick, R., Pugeault, N., Steedman, M., Krüger, N. and Wörgötter, F
Object Action Complexes as an Interface for Planning and Robot Control IEEE-RAS International Conference on Humanoid Robots (Humanoids 2006).
* Justus Piater, Mark Steedman, Florentin Wörgötter. Learning in PACO-PLUS.
References
Robot control
Robot architectures