5 research outputs found
Instance-based learning of affordances
The discovery of possible interactions with objects is a vital part of an exploration task for robots. An important subset of these possible interactions are affordances. Affordances describe what a specific object can afford to a specific agent, based on the capabilities of the agent and the properties of the object in relation to the agent. For example, a chair affords a human to be sat-upon, if the sitting area of the chair is approximately knee-high. In this work, an instance-based learning approach is made to discover these affordances solely through different visual representations of point cloud data of an object. The point clouds are acquired with a Microsoft Kinect sensor. Different representations are tested and evaluated against a set of point cloud data of various objects found in a living room environment
Temporal accumulation of oriented visual features
In this paper we present a framework for accumulating on-line a model of a moving object (e.g., when manipulated by a robot). The proposed scheme is based on Bayesian filtering of local features, filtering jointly position, orientation and appearance information. The work presented here is novel in two aspects: first, we use an estimation mechanism that updates iteratively not only geometrical information, but also appearance information. Second, we propose a probabilistic version of the classical n-scan criterion that allows us to select which features are preserved and which are discarded, while making use of the available uncertainty model.
The accumulated representations have been used in three different contexts: pose estimation, robotic grasping, and driver assistance scenario
Reasoning and understanding grasp affordances for robot manipulation
This doctoral research focuses on developing new methods that enable an artificial agent
to grasp and manipulate objects autonomously. More specifically, we are using the concept
of affordances to learn and generalise robot grasping and manipulation techniques. [75] defined affordances as the ability of an agent to perform a certain action with an object in a
given environment. In robotics, affordances defines the possibility of an agent to perform
actions with an object. Therefore, by understanding the relation between actions, objects
and the effect of these actions, the agent understands the task at hand, providing the robot
with the potential to bridge perception to action. The significance of affordances in robotics
has been studied from varied perspectives, such as psychology and cognitive sciences.
Many efforts have been made to pragmatically employ the concept of affordances as it
provides the potential for an artificial agent to perform tasks autonomously. We start by reviewing and finding common ground amongst different strategies that use affordances for
robotic tasks. We build on the identified grounds to provide guidance on including the concept of affordances as a medium to boost autonomy for an artificial agent. To this end, we
outline common design choices to build an affordance relation; and their implications on
the generalisation capabilities of the agent when facing previously unseen scenarios. Based
on our exhaustive review, we conclude that prior research on object affordance detection
is effective, however, among others, it has the following technical gaps: (i) the methods are
limited to a single object ↔ affordance hypothesis, and (ii) they cannot guarantee task completion or any level of performance for the manipulation task alone nor (iii) in collaboration
with other agents. In this research thesis, we propose solutions to these technical challenges.
In an incremental fashion, we start by addressing the limited generalisation capabilities
of, at the time state-of-the-art methods, by strengthening the perception to action connection through the construction of an Knowledge Base (KB). We then leverage the information
encapsulated in the KB to design and implement a reasoning and understanding method
based on statistical relational leaner (SRL) that allows us to cope with uncertainty in testing
environments, and thus, improve generalisation capabilities in affordance-aware manipulation tasks. The KB in conjunctions with our SRL are the base for our designed solutions
that guarantee task completion when the robot is performing a task alone as well as when in
collaboration with other agents. We finally expose and discuss a range of interesting avenues
that have the potential to thrive the capabilities of a robotic agent through the use of the
concept of affordances for manipulation tasks. A summary of the contributions of this thesis
can be found at: https://bit.ly/grasp_affordance_reasonin