26,390 research outputs found
CasIL: Cognizing and Imitating Skills via a Dual Cognition-Action Architecture
Enabling robots to effectively imitate expert skills in longhorizon tasks
such as locomotion, manipulation, and more, poses a long-standing challenge.
Existing imitation learning (IL) approaches for robots still grapple with
sub-optimal performance in complex tasks. In this paper, we consider how this
challenge can be addressed within the human cognitive priors. Heuristically, we
extend the usual notion of action to a dual Cognition (high-level)-Action
(low-level) architecture by introducing intuitive human cognitive priors, and
propose a novel skill IL framework through human-robot interaction, called
Cognition-Action-based Skill Imitation Learning (CasIL), for the robotic agent
to effectively cognize and imitate the critical skills from raw visual
demonstrations. CasIL enables both cognition and action imitation, while
high-level skill cognition explicitly guides low-level primitive actions,
providing robustness and reliability to the entire skill IL process. We
evaluated our method on MuJoCo and RLBench benchmarks, as well as on the
obstacle avoidance and point-goal navigation tasks for quadrupedal robot
locomotion. Experimental results show that our CasIL consistently achieves
competitive and robust skill imitation capability compared to other
counterparts in a variety of long-horizon robotic tasks
Action and behavior: a free-energy formulation
We have previously tried to explain perceptual inference and learning under a free-energy principle that pursues Helmholtzâs agenda to understand the brain in terms of energy minimization. It is fairly easy to show that making inferences about the causes of sensory data can be cast as the minimization of a free-energy bound on the likelihood of sensory inputs, given an internal model of how they were caused. In this article, we consider what would happen if the data themselves were sampled to minimize this bound. It transpires that the ensuing active sampling or inference is mandated by ergodic arguments based on the very existence of adaptive agents. Furthermore, it accounts for many aspects of motor behavior; from retinal stabilization to goal-seeking. In particular, it suggests that motor control can be understood as fulfilling prior expectations about proprioceptive sensations. This formulation can explain why adaptive behavior emerges in biological agents and suggests a simple alternative to optimal control theory. We illustrate these points using simulations of oculomotor control and then apply to same principles to cued and goal-directed movements. In short, the free-energy formulation may provide an alternative perspective on the motor control that places it in an intimate relationship with perception
How to Motivate Your Dragon: Teaching Goal-Driven Agents to Speak and Act in Fantasy Worlds.
We seek to create agents that both act and communicate with other agents in pursuit of a goal. Towards this end, we extend LIGHT (Urbanek et al. 2019)âa large-scale crowd-sourced fantasy text-gameâwith a dataset of quests. These contain natural language motivations paired with in-game goals and human demonstrations; completing a quest might require dialogue or actions (or both). We introduce a reinforcement learning system that (1) incorporates large-scale language modeling-based and commonsense reasoning-based pre-training to imbue the agent with relevant priors; and (2) leverages a factorized action space of action commands and dialogue, balancing between the two. We conduct zero-shot evaluations using held-out human expert demonstrations, showing that our agents are able to act consistently and talk naturally with respect to their motivations
How to Motivate Your Dragon: Teaching Goal-Driven Agents to Speak and Act in Fantasy Worlds
We seek to create agents that both act and communicate with other agents in
pursuit of a goal. Towards this end, we extend LIGHT (Urbanek et al. 2019)---a
large-scale crowd-sourced fantasy text-game---with a dataset of quests. These
contain natural language motivations paired with in-game goals and human
demonstrations; completing a quest might require dialogue or actions (or both).
We introduce a reinforcement learning system that (1) incorporates large-scale
language modeling-based and commonsense reasoning-based pre-training to imbue
the agent with relevant priors; and (2) leverages a factorized action space of
action commands and dialogue, balancing between the two. We conduct zero-shot
evaluations using held-out human expert demonstrations, showing that our agents
are able to act consistently and talk naturally with respect to their
motivations
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Judgement utility modulates the use of explicit contextual priors and visual information during anticipation
Objectives: We examined the impact of judgement utility on the use of explicit contextual priors and visual information during action anticipation in soccer.
Design: We employed a repeated measures design, in which expert soccer players had to perform a video-based anticipation task under various conditions.
Methods: The task required the players to predict the direction (left or right) of an oncoming opponentâs imminent actions. Performance and verbal reports of thoughts from players were compared across three conditions. In two of the conditions, contextual priors pertaining to the opponentâs action tendencies (dribbleâŻ=âŻ70%; passâŻ=âŻ30%) were explicitly provided. In one of these experimental conditions, players were told that an incorrect ârightâ response would result in conceding a goal, which created imbalanced judgement utility (leftâŻ=âŻhigh utility; rightâŻ=âŻlow utility). In the third control condition, no explicit contextual priors or additional instructions were provided.
Results: The explicit provision of contextual priors changed playersâ processing priorities, biased their anticipatory judgements in accordance with the opponentâs action tendencies, and enhanced anticipation performance. These effects were suppressed under conditions in which the explicit contextual priors were accompanied by imbalanced judgement utility. Under these conditions, the players were more concerned about the consequences of their judgements and were more inclined to opt for the direction with the higher utility.
Conclusions: It appears that judgement utility disrupts the integration of contextual priors and visual information, which results in decreased impact of explicit contextual priors during action anticipation
Unsupervised state representation learning with robotic priors: a robustness benchmark
Our understanding of the world depends highly on our capacity to produce
intuitive and simplified representations which can be easily used to solve
problems. We reproduce this simplification process using a neural network to
build a low dimensional state representation of the world from images acquired
by a robot. As in Jonschkowski et al. 2015, we learn in an unsupervised way
using prior knowledge about the world as loss functions called robotic priors
and extend this approach to high dimension richer images to learn a 3D
representation of the hand position of a robot from RGB images. We propose a
quantitative evaluation of the learned representation using nearest neighbors
in the state space that allows to assess its quality and show both the
potential and limitations of robotic priors in realistic environments. We
augment image size, add distractors and domain randomization, all crucial
components to achieve transfer learning to real robots. Finally, we also
contribute a new prior to improve the robustness of the representation. The
applications of such low dimensional state representation range from easing
reinforcement learning (RL) and knowledge transfer across tasks, to
facilitating learning from raw data with more efficient and compact high level
representations. The results show that the robotic prior approach is able to
extract high level representation as the 3D position of an arm and organize it
into a compact and coherent space of states in a challenging dataset.Comment: ICRA 2018 submissio
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