221 research outputs found
Symbol Emergence in Robotics: A Survey
Humans can learn the use of language through physical interaction with their
environment and semiotic communication with other people. It is very important
to obtain a computational understanding of how humans can form a symbol system
and obtain semiotic skills through their autonomous mental development.
Recently, many studies have been conducted on the construction of robotic
systems and machine-learning methods that can learn the use of language through
embodied multimodal interaction with their environment and other systems.
Understanding human social interactions and developing a robot that can
smoothly communicate with human users in the long term, requires an
understanding of the dynamics of symbol systems and is crucially important. The
embodied cognition and social interaction of participants gradually change a
symbol system in a constructive manner. In this paper, we introduce a field of
research called symbol emergence in robotics (SER). SER is a constructive
approach towards an emergent symbol system. The emergent symbol system is
socially self-organized through both semiotic communications and physical
interactions with autonomous cognitive developmental agents, i.e., humans and
developmental robots. Specifically, we describe some state-of-art research
topics concerning SER, e.g., multimodal categorization, word discovery, and a
double articulation analysis, that enable a robot to obtain words and their
embodied meanings from raw sensory--motor information, including visual
information, haptic information, auditory information, and acoustic speech
signals, in a totally unsupervised manner. Finally, we suggest future
directions of research in SER.Comment: submitted to Advanced Robotic
SERKET: An Architecture for Connecting Stochastic Models to Realize a Large-Scale Cognitive Model
To realize human-like robot intelligence, a large-scale cognitive
architecture is required for robots to understand the environment through a
variety of sensors with which they are equipped. In this paper, we propose a
novel framework named Serket that enables the construction of a large-scale
generative model and its inference easily by connecting sub-modules to allow
the robots to acquire various capabilities through interaction with their
environments and others. We consider that large-scale cognitive models can be
constructed by connecting smaller fundamental models hierarchically while
maintaining their programmatic independence. Moreover, connected modules are
dependent on each other, and parameters are required to be optimized as a
whole. Conventionally, the equations for parameter estimation have to be
derived and implemented depending on the models. However, it becomes harder to
derive and implement those of a larger scale model. To solve these problems, in
this paper, we propose a method for parameter estimation by communicating the
minimal parameters between various modules while maintaining their programmatic
independence. Therefore, Serket makes it easy to construct large-scale models
and estimate their parameters via the connection of modules. Experimental
results demonstrated that the model can be constructed by connecting modules,
the parameters can be optimized as a whole, and they are comparable with the
original models that we have proposed
Whole brain Probabilistic Generative Model toward Realizing Cognitive Architecture for Developmental Robots
Building a humanlike integrative artificial cognitive system, that is, an
artificial general intelligence, is one of the goals in artificial intelligence
and developmental robotics. Furthermore, a computational model that enables an
artificial cognitive system to achieve cognitive development will be an
excellent reference for brain and cognitive science. This paper describes the
development of a cognitive architecture using probabilistic generative models
(PGMs) to fully mirror the human cognitive system. The integrative model is
called a whole-brain PGM (WB-PGM). It is both brain-inspired and PGMbased. In
this paper, the process of building the WB-PGM and learning from the human
brain to build cognitive architectures is described.Comment: 55 pages, 8 figures, submitted to Neural Network
多層マルチモーダルLDAを用いた複数概念の統合に関する研究
知能ロボット開発において,ロボットが物体を扱うために,物体のカテゴリ分類だけではなく,物体と動きやその使い方など,物体概念と他の概念との関係を獲得する必要があると言える.さらに,ロボットによる真の理解を実現するために,場所や人物といった物事に対する概念の獲得も必要とする.本研究では,多層マルチモーダルLDA(mMLDA)に基づく,ロボットによる多様な概念形成及び統合を実現する.mMLDAによって,概念の形成と統合を同時に獲得が可能であるため,各概念の形成が互いに影響しあって,より正しく形成できる.さらに,我々が用いている言語もカテゴリに基づいており,ロボットもカテゴリ分類を通じて物体の概念を学習することで,未観測情報の予測や言語の理解が可能になると考えられる.言語理解のためのロボットによる語意の獲得問題についても,mMLDAを用いて実現することが可能である.本研究では,単語と概念間の相互情報量を用いることで,どの単語が本来どの概念に結びついているのかを自動的に推定する手法を提案する.また,単語と概念の結び付きを用いて,教示発話における概念の発火順を学習することが可能であり,これを学習することで,観測した情報を表現する文章を生成することができる.提案したこれらのモデルを実験によって,その有効性を示した.電気通信大学201
Symbol emergence as interpersonal cross-situational learning: the emergence of lexical knowledge with combinatoriality
We present a computational model for a symbol emergence system that enables
the emergence of lexical knowledge with combinatoriality among agents through a
Metropolis-Hastings naming game and cross-situational learning. Many
computational models have been proposed to investigate combinatoriality in
emergent communication and symbol emergence in cognitive and developmental
robotics. However, existing models do not sufficiently address category
formation based on sensory-motor information and semiotic communication through
the exchange of word sequences within a single integrated model. Our proposed
model facilitates the emergence of lexical knowledge with combinatoriality by
performing category formation using multimodal sensory-motor information and
enabling semiotic communication through the exchange of word sequences among
agents in a unified model. Furthermore, the model enables an agent to predict
sensory-motor information for unobserved situations by combining words
associated with categories in each modality. We conducted two experiments with
two humanoid robots in a simulated environment to evaluate our proposed model.
The results demonstrated that the agents can acquire lexical knowledge with
combinatoriality through interpersonal cross-situational learning based on the
Metropolis-Hastings naming game and cross-situational learning. Furthermore,
our results indicate that the lexical knowledge developed using our proposed
model exhibits generalization performance for novel situations through
interpersonal cross-modal inference
Multimodal Imitation using Self-learned Sensorimotor Representations
Although many tasks intrinsically involve multiple modalities, often only data from a single modality are used to improve complex robots acquisition of new skills. We present a method to equip robots with multimodal learning skills to achieve multimodal imitation on-the-fly on multiple concurrent task spaces, including vision, touch and proprioception, only using self-learned multimodal sensorimotor relations, without the need of solving inverse kinematic problems or explicit analytical models formulation. We evaluate the proposed method on a humanoid iCub robot learning to interact with a piano keyboard and imitating a human demonstration. Since no assumptions are made on the kinematic structure of the robot, the method can be also applied to different robotic platforms
A whole brain probabilistic generative model: Toward realizing cognitive architectures for developmental robots
Building a human-like integrative artificial cognitive system, that is, an artificial general intelligence (AGI), is the holy grail of the artificial intelligence (AI) field. Furthermore, a computational model that enables an artificial system to achieve cognitive development will be an excellent reference for brain and cognitive science. This paper describes an approach to develop a cognitive architecture by integrating elemental cognitive modules to enable the training of the modules as a whole. This approach is based on two ideas: (1) brain-inspired AI, learning human brain architecture to build human-level intelligence, and (2) a probabilistic generative model (PGM)-based cognitive architecture to develop a cognitive system for developmental robots by integrating PGMs. The proposed development framework is called a whole brain PGM (WB-PGM), which differs fundamentally from existing cognitive architectures in that it can learn continuously through a system based on sensory-motor information.In this paper, we describe the rationale for WB-PGM, the current status of PGM-based elemental cognitive modules, their relationship with the human brain, the approach to the integration of the cognitive modules, and future challenges. Our findings can serve as a reference for brain studies. As PGMs describe explicit informational relationships between variables, WB-PGM provides interpretable guidance from computational sciences to brain science. By providing such information, researchers in neuroscience can provide feedback to researchers in AI and robotics on what the current models lack with reference to the brain. Further, it can facilitate collaboration among researchers in neuro-cognitive sciences as well as AI and robotics
3D Robotic Sensing of People: Human Perception, Representation and Activity Recognition
The robots are coming. Their presence will eventually bridge the digital-physical divide and dramatically impact human life by taking over tasks where our current society has shortcomings (e.g., search and rescue, elderly care, and child education). Human-centered robotics (HCR) is a vision to address how robots can coexist with humans and help people live safer, simpler and more independent lives.
As humans, we have a remarkable ability to perceive the world around us, perceive people, and interpret their behaviors. Endowing robots with these critical capabilities in highly dynamic human social environments is a significant but very challenging problem in practical human-centered robotics applications.
This research focuses on robotic sensing of people, that is, how robots can perceive and represent humans and understand their behaviors, primarily through 3D robotic vision. In this dissertation, I begin with a broad perspective on human-centered robotics by discussing its real-world applications and significant challenges. Then, I will introduce a real-time perception system, based on the concept of Depth of Interest, to detect and track multiple individuals using a color-depth camera that is installed on moving robotic platforms. In addition, I will discuss human representation approaches, based on local spatio-temporal features, including new “CoDe4D” features that incorporate both color and depth information, a new “SOD” descriptor to efficiently quantize 3D visual features, and the novel AdHuC features, which are capable of representing the activities of multiple individuals. Several new algorithms to recognize human activities are also discussed, including the RG-PLSA model, which allows us to discover activity patterns without supervision, the MC-HCRF model, which can explicitly investigate certainty in latent temporal patterns, and the FuzzySR model, which is used to segment continuous data into events and probabilistically recognize human activities. Cognition models based on recognition results are also implemented for decision making that allow robotic systems to react to human activities. Finally, I will conclude with a discussion of future directions that will accelerate the upcoming technological revolution of human-centered robotics
Affective Computing
This book provides an overview of state of the art research in Affective Computing. It presents new ideas, original results and practical experiences in this increasingly important research field. The book consists of 23 chapters categorized into four sections. Since one of the most important means of human communication is facial expression, the first section of this book (Chapters 1 to 7) presents a research on synthesis and recognition of facial expressions. Given that we not only use the face but also body movements to express ourselves, in the second section (Chapters 8 to 11) we present a research on perception and generation of emotional expressions by using full-body motions. The third section of the book (Chapters 12 to 16) presents computational models on emotion, as well as findings from neuroscience research. In the last section of the book (Chapters 17 to 22) we present applications related to affective computing
A motion-based approach for audio-visual automatic speech recognition
The research work presented in this thesis introduces novel approaches for both visual
region of interest extraction and visual feature extraction for use in audio-visual
automatic speech recognition. In particular, the speaker‘s movement that occurs
during speech is used to isolate the mouth region in video sequences and motionbased
features obtained from this region are used to provide new visual features for
audio-visual automatic speech recognition. The mouth region extraction approach
proposed in this work is shown to give superior performance compared with existing
colour-based lip segmentation methods. The new features are obtained from three
separate representations of motion in the region of interest, namely the difference in
luminance between successive images, block matching based motion vectors and
optical flow. The new visual features are found to improve visual-only and audiovisual
speech recognition performance when compared with the commonly-used
appearance feature-based methods.
In addition, a novel approach is proposed for visual feature extraction from either the
discrete cosine transform or discrete wavelet transform representations of the mouth
region of the speaker. In this work, the image transform is explored from a new
viewpoint of data discrimination; in contrast to the more conventional data
preservation viewpoint. The main findings of this work are that audio-visual
automatic speech recognition systems using the new features extracted from the
frequency bands selected according to their discriminatory abilities generally
outperform those using features designed for data preservation.
To establish the noise robustness of the new features proposed in this work, their
performance has been studied in presence of a range of different types of noise and at
various signal-to-noise ratios. In these experiments, the audio-visual automatic speech
recognition systems based on the new approaches were found to give superior
performance both to audio-visual systems using appearance based features and to
audio-only speech recognition systems
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