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Masashi Hamaya

41 accepted papers

2026

Robust and Resilient Soft Robotic Object Insertion with Compliance-Enabled Contact Formation and Failure Recovery

ICRA 2026poster

We address robust and resilient object insertion using a passively compliant soft wrist that permits large deformations and safely absorbs contacts, without high-frequency control or force sensing. To improve robustness, we structure the task as compliance-enabled contact formations: a sequence of c…

2026

SCU-Hand with Integrated Single-Sheet Valve: A Funnel-Shaped Robotic Hand for Milligram-Scale Powder Handling

ICRA 2026poster

Laboratory Automation (LA) has the potential to accelerate solid-state materials discovery by enabling continuous robotic operation without human intervention. While robotic systems have been developed for tasks such as powder grinding and X-ray diffraction (XRD) analysis, fully automating powder ha…

2026

Simulation-Driven Evolutionary Motion Parameterization for Contact-Rich Granular Scooping with a Soft Conical Robotic Hand

ICRA 2026poster

Tool-based scooping is vital in robot-assisted tasks, enabling interaction with objects of varying sizes, shapes, and material states. Recent studies have shown that flexible, reconfigurable soft robotic end-effectors can adapt their shape to maintain consistent contact with container surfaces durin…

2026

Tactile Memory With Soft Robot: Robust Object Insertion via Masked Encoding and Soft Wrist

RA-L 2026

Tactile memory, the ability to store and retrieve touch-based experience, is critical for contact-rich tasks such as key insertion under uncertainty. To replicate this capability, we introduce Tactile Memory with Soft Robot (TaMeSo-bot), a system that integrates a soft wrist with tactile retrieval-b

Cited by 0SourceScholar
2025

Near-Optimal Policy Identification in Robust Constrained Markov Decision Processes via Epigraph Form

ICLR 2025poster

Designing a safe policy for uncertain environments is crucial in real-world control systems. However, this challenge remains inadequately addressed within the Markov decision process (MDP) framework. This paper presents the first algorithm guaranteed to identify a near-optimal policy in a robust con…

2025

Pose Estimation of a Cable-Driven Serpentine Manipulator Utilizing Intrinsic Dynamics via Physical Reservoir Computing

IROS 2025

Cable-driven serpentine manipulators hold great potential in unstructured environments, offering obstacle avoidance, multi-directional force application, and a lightweight design. By placing all motors and sensors at the base and employing plastic links, we can further reduce the arm’s weight. To de

Cited by 0SourceScholar
2025

SCU-Hand: Soft Conical Universal Robotic Hand for Scooping Granular Media from Containers of Various Sizes

ICRA 2025

Automating small-scale experiments in materials science presents challenges due to the heterogeneous nature of experimental setups. This study introduces the SCU-Hand (Soft Conical Universal Robot Hand), a novel end-effector designed to automate the task of scooping powdered samples from various con

Cited by 4SourceScholar
2024

An Electromagnetism-Inspired Method for Estimating In-Grasp Torque from Visuotactile Sensors

ICRA 2024poster

Tactile sensing has become a popular sensing modality for robot manipulators, due to the promise of providing robots with the ability to measure the rich contact information that gets transmitted through its sense of touch. Among the diverse range of information accessible from tactile sensors, torq…

Cited by 2SourceScholar
2024

Learning Variable Compliance Control From a Few Demonstrations for Bimanual Robot with Haptic Feedback Teleoperation System

IROS 2024poster

Automating dexterous, contact-rich manipulation tasks using rigid robots is a significant challenge in robotics. Rigid robots, defined by their actuation through position commands, face issues of excessive contact forces due to their inability to adapt to contact with the environment, potentially ca…

Cited by 13SourcecodeScholar
2024

Low-Cost Air Hockey Robot Using a Five-Bar Linkage Mechanism Driven by Position-Control Servomotors

IROS 2024poster

In human-robot interaction (HRI) research, ball games pose significant challenges that demand robotic solutions that are both cost-effective and user-friendly for non-experts. Air hockey, characterized by safe, non-direct-contact play and a simplified state-action space, emerges as an ideal platform…

Cited by 0SourceScholar
2024

Robotic Object Insertion with a Soft Wrist through Sim-to-Real Privileged Training

IROS 2024poster

This study addresses contact-rich object insertion tasks under unstructured environments using a robot with a soft wrist, enabling safe contact interactions. For the unstructured environments, we assume that there are uncertainties in object grasp and hole pose and that the soft wrist pose cannot be…

Cited by 1SourceScholar
2024

SliceIt! - A Dual Simulator Framework for Learning Robot Food Slicing

ICRA 2024poster

Cooking robots can enhance the home experience by reducing the burden of daily chores. However, these robots must perform their tasks dexterously and safely in shared human environments, especially when handling dangerous tools such as kitchen knives. This study focuses on enabling a robot to autono…

Cited by 6SourcecodeScholar
2024

Symmetry-aware Reinforcement Learning for Robotic Assembly under Partial Observability with a Soft Wrist

ICRA 2024poster

This study tackles the representative yet challenging contact-rich peg-in-hole task of robotic assembly, using a soft wrist that can operate more safely and tolerate lower-frequency control signals than a rigid one. Previous studies often use a fully observable formulation, requiring external setups…

Cited by 10SourcecodeScholar
2024

Vision-Language Interpreter for Robot Task Planning

ICRA 2024poster

Large language models (LLMs) are accelerating the development of language-guided robot planners. Meanwhile, symbolic planners offer the advantage of interpretability. This paper proposes a new task that bridges these two trends, namely, multimodal planning problem specification. The aim is to genera…

Cited by 62SourcecodeScholar
2024

Visuo-Tactile Zero-Shot Object Recognition with Vision-Language Model

IROS 2024poster

Tactile perception is vital, especially when distinguishing visually similar objects. We propose an approach to incorporate tactile data into a Vision-Language Model (VLM) for visuo-tactile zero-shot object recognition. Our approach leverages the zero-shot capability of VLMs to infer tactile propert…

Cited by 1SourceScholar
2023

Learning Food Picking without Food: Fracture Anticipation by Breaking Reusable Fragile Objects

ICRA 2023poster

Food picking is trivial for humans but not for robots, as foods are fragile. Presetting foods' physical properties does not help robots much due to the objects' inter- and intra-category diversity. A recent study proved that learning-based fracture anticipation with tactile sensors could overcome th…

Cited by 3SourceScholar
2023

Learning Robotic Assembly by Leveraging Physical Softness and Tactile Sensing

IROS 2023poster

This study aims to achieve autonomous robotic assembly under uncertain conditions arising from imprecise goal positioning and variations in the angle of the grasped part. Soft robots are suitable for such uncertain and contact-rich environments and are capable of insertion tasks with imprecise goal…

Cited by 9SourceScholar
2023

Learning Robotic Powder Weighing from Simulation for Laboratory Automation

IROS 2023poster

This study focuses on a robotic powder weighing task used in laboratory automation. In this task, a robot weighs a certain amount of powder with a milligram-level target mass using a dispensing spoon. The complex dynamics of the powder, the variations in the materials being weighed, and the need to…

Cited by 7SourceScholar
2023

Robotic Powder Grinding with Audio-Visual Feedback for Laboratory Automation in Materials Science

IROS 2023poster

This study focuses on the powder grinding process, which is a necessary step for material synthesis in materials science experiments. In material science, powder grinding is a time-consuming process that is typically executed by hand, as commercial grinding machines are unsuitable for samples of sma…

Cited by 1SourceScholar
2023

Twist Snake: Plastic table-top cable-driven robotic arm with all motors located at the base link

ICRA 2023poster

Table-top robotic arms for education and research must be low-cost for availability and lightweight and soft for safety. Therefore, as such a robot, this study focuses on designing a plastic table-top cable-driven robotic arm with all motors located at the base link. However, locating all motors at…

Cited by 6SourceScholar
2022

Robotic Powder Grinding with a Soft Jig for Laboratory Automation in Material Science

IROS 2022poster

Grinding materials into a fine powder is a time-consuming task in material science that is generally performed by hand, as current automated grinding machines might not be suitable for preparing small-sized samples. This study presents a robotic powder grinding system for laboratory automation in ma…

Cited by 11SourceScholar
2022

Sample-Efficient Learning of Deformable Linear Object Manipulation in the Real World Through Self-Supervision

RA-L 2022

Deformable object manipulation has potential for a wide range of real-world applications, but is still largely unsolved due to the complex dynamics and difficulty of state estimation. Learning-based approaches have recently accelerated progress, but generally depend heavily on large simulated datase

Cited by 21SourceScholar
2022

Uncertainty-Aware Manipulation Planning Using Gravity and Environment Geometry

RA-L 2022

Factory automation robot systems often depend on specially-made jigs that precisely position each part, which increases the system's cost and limits flexibility. We propose a method to determine the 3D pose of an object with high precision and confidence, using only parallel robotic grippers and no

Cited by 9SourceScholar
2021

An analytical diabolo model for robotic learning and control

ICRA 2021poster

In this paper, we present a diabolo model that can be used for training agents in simulation to play diabolo, as well as running it on a real dual robot arm system. We first derive an analytical model of the diabolo-string system and compare its accuracy using data recorded via motion capture, which…

Cited by 9SourceScholar
2021

Learning Robotic Contact Juggling

IROS 2021poster

Robotic contact juggling is a challenging task in which robots must control the movement of a ball rapidly and indirectly without holding it while keeping the ball in and sometimes out of contact with the robot’s body. In this work, we address the problem of learning such robotic contact juggling fr…

Cited by 4SourceScholar
2021

Precise Multi-Modal In-Hand Pose Estimation using Low-Precision Sensors for Robotic Assembly

ICRA 2021poster

In industrial assembly tasks, the in-hand pose of grasped objects needs to be known with high precision for subsequent manipulation tasks such as insertion. This problem (in-hand-pose estimation) has traditionally been addressed using visual recognition or tactile sensing. On the one hand, while vis…

Cited by 36SourceScholar
2021

Robotic Learning From Advisory and Adversarial Interactions Using a Soft Wrist

RA-L 2021

In this letter, we developed a novel learning framework from physical human-robot interactions. Owing to human domain knowledge, such interactions can be useful for facilitation of learning. However, applying numerous interactions for training data might place a burden on human users, particularly i

Cited by 6SourceScholar
2021

TRANS-AM: Transfer Learning by Aggregating Dynamics Models for Soft Robotic Assembly

ICRA 2021poster

Practical industrial assembly scenarios often require robotic agents to adapt their skills to unseen tasks quickly. While transfer reinforcement learning (RL) could enable such quick adaptation, much prior work has to collect many samples from source environments to learn target tasks in a model-fre…

Cited by 18SourceScholar
2020

A Compact, Cable-driven, Activatable Soft Wrist with Six Degrees of Freedom for Assembly Tasks

IROS 2020poster

Physical softness has been proposed to absorb impacts when establishing contact with a robot or its workpiece, to relax control requirements and improve performance in assembly and insertion tasks. Previous work has focused on special end effector solutions for isolated tasks, such as the peg-in-hol…

Cited by 35SourceScholar
2020

Contact-based in-hand pose estimation using Bayesian state estimation and particle filtering

ICRA 2020poster

In industrial assembly tasks, the position of an object grasped by the robot has to be known with high precision in order to insert or place it. In real applications, this problem is commonly solved by jigs that are specially produced for each part. However, they significantly limit flexibility and…

Cited by 30SourceScholar
2020

EXI-Net: EXplicitly/Implicitly Conditioned Network for Multiple Environment Sim-to-Real Transfer

CoRL 2020

Sim-to-real transfer is attractive for robot learning, as it avoids the high cost of collecting data with real robots, but transferring agents from simulation to the real world is challenging. Previous studies have presented promising methods to solve this problem, but they may fail when a wider ran

Cited by 0SourcePDFScholar
2020

Learning Robotic Assembly Tasks with Lower Dimensional Systems by Leveraging Physical Softness and Environmental Constraints

ICRA 2020poster

In this study, we present a novel control framework for assembly tasks with a soft robot. Typically, existing hard robots require high frequency controllers and precise force/torque sensors for assembly tasks. The resulting robot system is complex, entailing large amounts of engineering and maintena…

Cited by 34SourceScholar
2020

Learning Soft Robotic Assembly Strategies from Successful and Failed Demonstrations

IROS 2020poster

Physically soft robots are promising for robotic assembly tasks as they allow stable contacts with the environment. In this study, we propose a novel learning system for soft robotic assembly strategies. We formulate this problem as a reinforcement learning task and design the reward function from h…

Cited by 24SourceScholar
2020

MULTIPOLAR: Multi-Source Policy Aggregation for Transfer Reinforcement Learning between Diverse Environmental Dynamics

IJCAI 2020poster

Transfer reinforcement learning (RL) aims at improving the learning efficiency of an agent by exploiting knowledge from other source agents trained on relevant tasks. However, it remains challenging to transfer knowledge between different environmental dynamics without having access to the source en…

2019

Exploiting Human and Robot Muscle Synergies for Human-in-the-loop Optimization of EMG-based Assistive Strategies

ICRA 2019poster

In this study, we propose a novel human-in-the-loop optimization approach for exoskeleton robot control. We develop a method to optimize widely-used Electromyography (EMG)-based assistive strategies. If we use multiple EMG channels to control multi-DoF robots, optimization process becomes complex an…

Cited by 12SourceScholar
2017

Learning task-parametrized assistive strategies for exoskeleton robots by multi-task reinforcement learning

ICRA 2017poster

Recent studies suggest that reinforcement learning has great potential for generating assistive strategies in exoskeletons through physical interactions between a user and a robot. Previous methods focused on a task-specific assistive strategy, where for every single task (situation/context), the us…

Cited by 24SourceScholar
2017

User-robot collaborative excitation for PAM model identification in exoskeleton robots

IROS 2017poster

Pneumatic Artificial Muscle (PAM) actuators have been used as exoskeletons because of their inherited compliance and high power-weight ratio. However, creating accurate models remains difficult mainly due to the compliance issue; the model can be changed by the force applied by the user. Therefore,…

Cited by 11SourceScholar
2016

Dry-wireless EEG and asynchronous adaptive feature extraction towards a plug-and-play co-adaptive brain robot interface

ICRA 2016

This paper introduces a novel asynchronous adaptive brain machine interface (BMI), based on a dry-wireless headset, to trigger the movement of a lower limb exoskeleton robot by foot motor imagery. Specifically, it addresses two issues that are critical for the development of a plug-and-play brain ro

Cited by 21SourceScholar
2016

Learning assistive strategies from a few user-robot interactions: Model-based reinforcement learning approach

ICRA 2016

Designing an assistive strategy for exoskeletons is a key ingredient in movement assistance and rehabilitation. While several approaches have been explored, most studies are based on mechanical models of the human user, i.e., rigid-body dynamics or Center of Mass (CoM)-Zero Moment Point (ZMP) invert

Cited by 25SourceScholar
2015

Towards balance recovery control for lower body exoskeleton robots with Variable Stiffness Actuators: Spring-loaded flywheel model

ICRA 2015poster

This paper presents a biologically-inspired real-time balance recovery control strategy that is applied to a lower body exoskeleton with variable physical stiffness actuators at its ankle joints. For this purpose, a torsional spring-loaded flywheel model is presented to encapsulate both approximated…

Cited by 13SourceScholar