Catadioptric imaging systems use curved mirrors to capture wide fields of view. However, due to the curvature of the mirror, these systems tend to have very limited depth of field (DOF), with the point spread function (PSF) varying dramatically over the field of view and as a function of scene depth. In recent years, focal sweep has been used extensively to extend the DOF of conventional imaging systems. It has been shown that focal sweep produces an integrated point spread function (IPSF) that is nearly space-invariant and depth-invariant, enabling the recovery of an extended depth of field (EDOF) image by deconvolving the captured focal sweep image with a single IPSF. In this paper, we use focal sweep to extend the DOF of a catadioptric imaging system. We show that while the IPSF is spatially varying when a curved mirror is used, it remains quasi depth-invariant over the wide field of view of the imaging system. We have developed a focal sweep system where mirrors of different shapes can be used to capture wide field of view EDOF images. In particular, we show experimental results using spherical and paraboloidal mirrors.

This paper proposes a model that enables a robot to predict and imitate the motions of another by reusing its body forward-inverse model. Our model includes three approaches: (i) projection of a self-forward model for predicting phenomena in the external environment (other individuals), (ii) ldquotriadic relationrdquo that is mediation by a physical object between self and others, (iii) introduction of infant imitation by a parent. The recurrent neural network with parametric bias (RNNPB) model is used as the robot's self forward-inverse model. A group of hierarchical neural networks are attached to the RNNPB model as ldquoconversion modulesrdquo. Experiments demonstrated that a robot with our model could imitate a human's motions by translating the viewpoint. It could also discriminate known/unknown motions appropriately, and associate whole motion dynamics from only one motion snap image.

Consistency of object dynamics, which is related to reliable predictability, is an important factor for generating object manipulation motions. This paper proposes a technique to generate autonomous motions based on consistency of object dynamics. The technique resolves two issues: construction of an object dynamics prediction model and evaluation of consistency. The authors utilize Recurrent Neural Network with Parametric Bias to self-organize the dynamics, and link static images to the self-organized dynamics using a hierarchical neural network to deal with the first issue. For evaluation of consistency, the authors have set an evaluation function based on object dynamics relative to robot motor dynamics. Experiments have shown that the method is capable of predicting 90% of unknown object dynamics. Motion generation experiments have proved that the technique is capable of generating autonomous pushing motions that generate consistent rolling motions.

This paper presents a method to autonomously extract object features that describe their dynamics from active sensing experiences. The model is composed of a dynamics learning module and a feature extraction module. Recurrent Neural Network with Parametric Bias (RNNPB) is utilized for the dynamics learning module, learning and self-organizing the sequences of robot and object motions. A hierarchical neural network is linked to the input of RNNPB as the feature extraction module for extracting object features that describe the object motions. The two modules are simultaneously trained using image and motion sequences acquired from the robotpsilas active sensing with objects. Experiments are performed with the robotpsilas pushing motion with a variety of objects to generate sliding, falling over, bouncing, and rolling motions. The results have shown that the model is capable of extracting features that distinguish the characteristics of object dynamics.

This paper proposes a novel model which enables a humanoid robot infant to discover other individual (e.g. human parent). In this work, the authors define “other individual” as an actor which can be predicted by a self-model. For modeling the developmental process of discovering ability, the following three approaches are employed. (i) Projection of a selfmodel for predicting other individual’s actions. (ii) Mediation by a physical object between self and other individual. (iii) Introduction of infant imitation by parent. For creating the self-model of a robot, we apply Recurrent Neural Network with Parametric Bias (RNNPB) model which can learn the robot’s body dynamics. For the other-model of a human, conventional hierarchical neural networks are attached to the RNNPB model as “conversion modules”. Our target task is a moving an object. For evaluation of our model, human discovery experiments by the robot projecting its self-model were conducted. The results demonstrated that our method enabled the robot to predict the human’s motions, and to estimate the human’s position fairly accurately, which proved its adequacy.

Robot imitation is a useful and promising alternative to robot programming. Robot imitation involves two crucial issues. The first is how a robot can imitate a human whose physical structure and properties differ greatly from its own. The second is how the robot can generate various motions from finite programmable patterns (generalization). This paper describes a novel approach to robot imitation based on its own physical experiences. Let us consider a target task of moving an object on a table. For imitation, we focused on an active sensing process in which the robot acquires the relation between the object's motion and its own arm motion. For generalization, we applied a recurrent neural network with parametric bias (RNNPB) model to enable recognition/generation of imitation motions. The robot associates the arm motion which reproduces the observed object's motion presented by a human operator. Experimental results demonstrated that our method enabled the robot to imitate not only motion it has experienced but also unknown motion, which proved its capability for generalization