Affordance Equivalences in Robotics: A Formalism

Abstract

Automatic knowledge grounding is still an open problem in cognitive robotics. Recent research in developmental robotics suggests that a robot's interaction with its environment is a valuable source for collecting such knowledge about the effects of robot's actions. A useful concept for this process is that of an affordance, defined as a relationship between an actor, an action performed by this actor, an object on which the action is performed, and the resulting effect. This paper proposes a formalism for defining and identifying affordance equivalence. By comparing the elements of two affordances, we can identify equivalences between affordances, and thus acquire grounded knowledge for the robot. This is useful when changes occur in the set of actions or objects available to the robot, allowing to find alternative paths to reach goals. In the experimental validation phase we verify if the recorded interaction data is coherent with the identified affordance equivalences. This is done by querying a Bayesian Network that serves as container for the collected interaction data, and verifying that both affordances considered equivalent yield the same effect with a high probability.

Tool Macgyvering: Tool Construction Using Geometric Reasoning

“…Prior work on affordance representations [19], has defined object equivalence (O eq ) as occurring when the same action applied to two different objects generates an equivalent effect. Similarly, object-action equivalence (OA eq ) is defined as occurring when different actions applied to different objects result in equivalent effects.…”

Toward Self-Aware Robots

“…We follow the definition of an affordance employed in Andries et al ( 2018 ), where we consider O the set of objects, A the set of actions, and E the set of observable effects. When an actor g m applies an action a l on object o k , generating the effect e j , the corresponding affordance α is defined as:…”

Examples of Gibsonian Affordances in Legged Robotics Research Using an Empirical, Generative Framework

“…However, the robotics research often considered to exemplify the application of ecological concepts like affordances to robotics is generally either oriented toward building representations of affordances (Şahin et al, 2007;Zech et al, 2017;Andries et al, 2018;Hassanin et al, 2018) or toward biomimetic implementations of specific animal behaviors or capabilities (Beer, 1997;Cruse et al, 1998;Webb and Consilvio, 2001;Ijspeert, 2014) which then act as models for testing biological hypotheses (Webb, 2001(Webb, , 2006. When non-biomimetic robotics research oriented toward coordinating simple controllers is considered (e.g., Braitenberg, 1986;Brooks, 1986;Raibert, 1986;Arkin, 1998), it is inevitably decades old.…”