body schema
Adaptive Body Schema Learning System Considering Additional Muscles for Musculoskeletal Humanoids
Kawaharazuka, Kento, Miki, Akihiro, Toshimitsu, Yasunori, Okada, Kei, Inaba, Masayuki
One of the important advantages of musculoskeletal humanoids is that the muscle arrangement can be easily changed and the number of muscles can be increased according to the situation. In this study, we describe an overall system of muscle addition for musculoskeletal humanoids and the adaptive body schema learning while taking into account the additional muscles. For hardware, we describe a modular body design that can be fitted with additional muscles, and for software, we describe a method that can learn the changes in body schema associated with additional muscles from a small amount of motion data. We apply our method to a simple 1-DOF tendon-driven robot simulation and the arm of the musculoskeletal humanoid Musashi, and show the effectiveness of muscle tension relaxation by adding muscles for a high-load task.
Restoration of Reduced Self-Efficacy Caused by Chronic Pain through Manipulated Sensory Discrepancy
Itkonen, Matti, Kawabata, Riku, Yamauchi, Satsuki, Okajima, Shotaro, Hirata, Hitoshi, Shimoda, Shingo
Abstract-- Human physical function is governed by selfefficacy, the belief in one's motor capacity. In chronic pain patients, this capacity may remain reduced long after the damage causing the pain has been cured. Chronic pain alters body schema, affecting how patients perceive the dimension and pose of their bodies. We exploit this deficit using robotic manipulation technology and augmented sensory stimuli through virtual reality technology. We propose a sensory stimuli manipulation method aimed at modifying body schema to restore lost selfefficacy. Pharmaceuticals alone cannot cure this complex condition, which is influenced by biological, psychological, and social factors [1].
GeMuCo: Generalized Multisensory Correlational Model for Body Schema Learning
Kawaharazuka, Kento, Okada, Kei, Inaba, Masayuki
Humans can autonomously learn the relationship between sensation and motion in their own bodies, estimate and control their own body states, and move while continuously adapting to the current environment. On the other hand, current robots control their bodies by learning the network structure described by humans from their experiences, making certain assumptions on the relationship between sensors and actuators. In addition, the network model does not adapt to changes in the robot's body, the tools that are grasped, or the environment, and there is no unified theory, not only for control but also for state estimation, anomaly detection, simulation, and so on. In this study, we propose a Generalized Multisensory Correlational Model (GeMuCo), in which the robot itself acquires a body schema describing the correlation between sensors and actuators from its own experience, including model structures such as network input/output. The robot adapts to the current environment by updating this body schema model online, estimates and controls its body state, and even performs anomaly detection and simulation. We demonstrate the effectiveness of this method by applying it to tool-use considering changes in grasping state for an axis-driven robot, to joint-muscle mapping learning for a musculoskeletal robot, and to full-body tool manipulation for a low-rigidity plastic-made humanoid.
Hardware Design and Learning-Based Software Architecture of Musculoskeletal Wheeled Robot Musashi-W for Real-World Applications
Kawaharazuka, Kento, Miki, Akihiro, Bando, Masahiro, Suzuki, Temma, Ribayashi, Yoshimoto, Toshimitsu, Yasunori, Nagamatsu, Yuya, Okada, Kei, Inaba, and Masayuki
Various musculoskeletal humanoids have been developed so far. While these humanoids have the advantage of their flexible and redundant bodies that mimic the human body, they are still far from being applied to real-world tasks. One of the reasons for this is the difficulty of bipedal walking in a flexible body. Thus, we developed a musculoskeletal wheeled robot, Musashi-W, by combining a wheeled base and musculoskeletal upper limbs for real-world applications. Also, we constructed its software system by combining static and dynamic body schema learning, reflex control, and visual recognition. We show that the hardware and software of Musashi-W can make the most of the advantages of the musculoskeletal upper limbs, through several tasks of cleaning by human teaching, carrying a heavy object considering muscle addition, and setting a table through dynamic cloth manipulation with variable stiffness.
Body Schema Acquisition through Active Learning
Martinez-Cantin, Ruben, Lopes, Manuel, Montesano, Luis
We present an active learning algorithm for the problem of body schema learning, i.e. estimating a kinematic model of a serial robot. The learning process is done online using Recursive Least Squares (RLS) estimation, which outperforms gradient methods usually applied in the literature. In addiction, the method provides the required information to apply an active learning algorithm to find the optimal set of robot configurations and observations to improve the learning process. By selecting the most informative observations, the proposed method minimizes the required amount of data. We have developed an efficient version of the active learning algorithm to select the points in real-time. The algorithms have been tested and compared using both simulated environments and a real humanoid robot.
Motion Planning on Visual Manifolds
In this thesis, we propose an alternative characterization of the notion of Configuration Space, which we call Visual Configuration Space (VCS). This new characterization allows an embodied agent (e.g., a robot) to discover its own body structure and plan obstacle-free motions in its peripersonal space using a set of its own images in random poses. Here, we do not assume any knowledge of geometry of the agent, obstacles or the environment. We demonstrate the usefulness of VCS in (a) building and working with geometry-free models for robot motion planning, (b) explaining how a human baby might learn to reach objects in its peripersonal space through motor babbling, and (c) automatically generating natural looking head motion animations for digital avatars in virtual environments. This work is based on the formalism of manifolds and manifold learning using the agent's images and hence we call it Motion Planning on Visual Manifolds.
AIhub coffee corner: can AI make humans better?
This month, we ask if AI can make humans better. Joining the discussion this time are: Joe Daly (AIhub and University of Bristol), Tom Dietterich (Oregon State University), Sabine Hauert (University of Bristol), Sarit Kraus (Bar-Ilan University), Michael Littman (Brown University), Lucy Smith (AIhub) and Oskar von Stryk (Technische Universität Darmstadt). Joe Daly: I recently saw this Twitter thread, about how AI has made human players better at the game of Go, then this article about the game of bridge, and more generally about AI's influence on us. People were actually discussing how AI can make us better at stuff, and how we can learn things from AI. What are people's thoughts on that?
Sensorimotor representation learning for an "active self" in robots: A model survey
Nguyen, Phuong D. H., Georgie, Yasmin Kim, Kayhan, Ezgi, Eppe, Manfred, Hafner, Verena Vanessa, Wermter, Stefan
For example, sensorimotor birth, infants spend their first months of life undergoing experiences are used to learn a forward model, and a many developmental milestones to incrementally develop forward model can be the basis for learning high-level the representation of their body. This body schema is cognitive conceptual representations. In agreement with related mainly to touch, proprioception, and vision (see Schillaci et al. (2016), we aim to go deeper into the role of Table 1) as these sensory modalities continue to develop multisensory information collected through exploration from the fetal stage (see Hoffmann, 2017; Adolph in the formation of an agent's body and peripersonal and Joh, 2007 for reviews). Later on, the representation space representation, and how these sensorimotor representations of the surrounding space of the body--the PPS--is affect the agent's sense of the active self, aggregated from the proprioceptive and exteroceptive including the sense of agency and the sense of body modalities (see Table 1). In addition, infants develop ownership. Thus, motor explorations will be mentioned the capability to generate motor actions corresponding but not exhaustively discussed in this surveyed work.
Robotic self-representation improves manipulation skills and transfer learning
Nguyen, Phuong D. H., Eppe, Manfred, Wermter, Stefan
Cognitive science suggests that the self-representation is critical for learning and problem-solving. However, there is a lack of computational methods that relate this claim to cognitively plausible robots and reinforcement learning. In this paper, we bridge this gap by developing a model that learns bidirectional action-effect associations to encode the representations of body schema and the peripersonal space from multisensory information, which is named multimodal BidAL. Through three different robotic experiments, we demonstrate that this approach significantly stabilizes the learning-based problem-solving under noisy conditions and that it improves transfer learning of robotic manipulation skills.
Bayesian Body Schema Estimation using Tactile Information obtained through Coordinated Random Movements
Mimura, Tomohiro, Hagiwara, Yoshinobu, Taniguchi, Tadahiro, Inamura, Tetsunari
This paper describes a computational model, called the Dirichlet process Gaussian mixture model with latent joints (DPGMM-LJ), that can find latent tree structure embedded in data distribution in an unsupervised manner. By combining DPGMM-LJ and a pre-existing body map formation method, we propose a method that enables an agent having multi-link body structure to discover its kinematic structure, i.e., body schema, from tactile information alone. The DPGMM-LJ is a probabilistic model based on Bayesian nonparametrics and an extension of Dirichlet process Gaussian mixture model (DPGMM). In a simulation experiment, we used a simple fetus model that had five body parts and performed structured random movements in a womb-like environment. It was shown that the method could estimate the number of body parts and kinematic structures without any pre-existing knowledge in many cases. Another experiment showed that the degree of motor coordination in random movements affects the result of body schema formation strongly. It is confirmed that the accuracy rate for body schema estimation had the highest value 84.6% when the ratio of motor coordination was 0.9 in our setting. These results suggest that kinematic structure can be estimated from tactile information obtained by a fetus moving randomly in a womb without any visual information even though its accuracy was not so high. They also suggest that a certain degree of motor coordination in random movements and the sufficient dimension of state space that represents the body map are important to estimate body schema correctly.