VLDB 2026 Research / reviewers in the wild / expert
Cristian C. Beltran-Hernandez
dblp:231/8764 · also Cristian Beltran, Cristian Camilo Beltran-Hernandez
· DBLP profile ↗
10ranked-venue papers
1as first author
10since 2021 · last 2025
0000-0002-1134-009XORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 10 · 1 first-author · 10 since 2021Systems, architecture and hardware · 9 · 1 first-author · 9 since 2021Software engineering, systems software and programming languages · 1 · 1 since 2021Databases, data management, data science and information retrieval · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | SCU-Hand: Soft Conical Universal Robotic Hand for Scooping Granular Media from Containers of Various SizesabstractAutomating 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 container sizes using a robotic arm. The SCU-Hand employs a flexible, conical structure that adapts to different container geometries through deformation, maintaining consistent contact without complex force sensing or machine learning-based control methods. Its reconfigurable mechanism allows for size adjustment, enabling efficient scooping from diverse container types. By combining soft robotics principles with a sheet-morphing design, our end-effector achieves high flexibility while retaining the necessary stiffness for effective powder manipulation. We detail the design principles, fabrication process, and experimental validation of the SCU-Hand. Experimental validation showed that the scooping capacity is about 20% higher than that of a commercial tool, with a scooping performance of more than 95% for containers of sizes between 67 mm to 110 mm. This research contributes to laboratory automation by offering a cost-effective, easily implementable solution for automating tasks such as materials synthesis and characterization processes. Tomoya Takahashi, Cristian C. Beltran-Hernandez, Yuki Kuroda, Kazutoshi Tanaka, Masashi Hamaya, Yoshitaka Ushiku |
ICRA | 2 |
| 2024 | Causal Organizational Mining in Software Engineering: Evaluating Improvement Strategies in Development Team DynamicsabstractIn the context of software engineering, analyzing causality in the dynamics of development teams is essential for optimizing performance. Causality involves understanding how certain factors (organizational structures, individual interactions) directly influence the team's performance, allowing for the identification and implementation of effective improvements in development processes. Identifying and understanding the underlying causes of heterogeneous effects in team dynamics is essential for improving collaboration and productivity. The lack of specific methodologies to explore these causal relationships in complex organizational settings limits the ability of project leaders to implement effective changes. This article describes a method that uses causal inference in organizational mining to assess software development teams. Data are analyzed to identify interactions and causal factors affecting role dynamics, and causal inference techniques are employed to evaluate the effects of improvement actions. The effectiveness of this approach was confirmed with a pilot software development team at a Chilean payment processing company. By employing causal organizational analysis methods, managers were able to select more focused strategies, based on a deep and detailed understanding of the underlying causal dynamics. This work contributes to the field of software engineering by introducing a structured and causal approach to analyze team dynamics and providing project managers with tools to address the underlying factors that hinder team effectiveness. Fernando Montoya, Cristian C. Beltran-Hernandez, Hernán Astudillo |
CLEI | 2 |
| 2024 | SliceIt! - A Dual Simulator Framework for Learning Robot Food SlicingabstractCooking 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 autonomously and safely learn food-cutting tasks. More specifically, our goal is to enable a collaborative robot or industrial robot arm to perform food-slicing tasks by adapting to varying material properties using compliance control. Our approach involves using Reinforcement Learning (RL) to train a robot to compliantly manipulate a knife, by reducing the contact forces exerted by the food items and by the cutting board. However, training the robot in the real world can be inefficient, and dangerous, and result in a lot of food waste. Therefore, we proposed SliceIt!, a framework for safely and efficiently learning robot food-slicing tasks in simulation. Following a real2sim2real approach, our framework consists of collecting a few real food slicing data, calibrating our dual simulation environment (a high-fidelity cutting simulator and a robotic simulator), learning compliant control policies on the calibrated simulation environment, and finally, deploying the policies on the real robot. Cristian C. Beltran-Hernandez, Nicolas Erbetti, Masashi Hamaya |
ICRA | 1 |
| 2024 | Symmetry-aware Reinforcement Learning for Robotic Assembly under Partial Observability with a Soft WristabstractThis 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 or estimators for the peg-to-hole pose. In contrast, we use a partially observable formulation and deep reinforcement learning from demonstrations to learn a memory-based agent that acts purely on haptic and proprioceptive signals. Moreover, previous works do not incorporate potential domain symmetry and thus must search for solutions in a bigger space. Instead, we propose to leverage the symmetry for sample efficiency by augmenting the training data and constructing auxiliary losses to force the agent to adhere to the symmetry. Results in simulation with five different symmetric peg shapes show that our proposed agent can be comparable to or even outperform a state-based agent. In particular, the sample efficiency also allows us to learn directly on the real robot within 3 hours. Tadashi Kozuno, Cristian C. Beltran-Hernandez, Masashi Hamaya |
ICRA | 3 |
| 2024 | Vision-Language Interpreter for Robot Task PlanningabstractLarge 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 generate a problem description (PD), a machine-readable file used by the planners to find a plan. By generating PDs from language instruction and scene observation, we can drive symbolic planners in a language-guided framework. We propose a Vision-Language Interpreter (ViLaIn), a new framework that generates PDs using state-of-the-art LLM and vision-language models. ViLaIn can refine generated PDs via error message feedback from the symbolic planner. Our aim is to answer the question: How accurately can ViLaIn and the symbolic planner generate valid robot plans? To evaluate ViLaIn, we introduce a novel dataset called the problem description generation (ProDG) dataset. The framework is evaluated with four new evaluation metrics. Experimental results show that ViLaIn can generate syntactically correct problems with more than 99% accuracy and valid plans with more than 58% accuracy. Our code and dataset are available at https://github.com/omron-sinicx/ViLaIn. Keisuke Shirai, Cristian C. Beltran-Hernandez, Masashi Hamaya, Atsushi Hashimoto 0001, Shohei Tanaka, Kento Kawaharazuka, Kazutoshi Tanaka, Yoshitaka Ushiku, Shinsuke Mori |
ICRA | 2 |
| 2024 | Robotic Object Insertion with a Soft Wrist through Sim-to-Real Privileged TrainingabstractThis 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 directly measured. Recent methods employ learning approaches and force/torque sensors for contact localization; however, they require data collection in the real world. This study proposes a sim-to-real approach using a privileged training strategy. This method has two steps. 1) The teacher policy is trained to complete the task with sensor inputs and ground truth privileged information such as the peg pose, and then 2) the student encoder is trained with data produced from teacher policy rollouts to estimate the privileged information from sensor history. We performed sim-to-real experiments under grasp and hole pose uncertainties. This resulted in 100%, 95%, and 80% success rates for circular peg insertion with 0°, +5°, and -5° peg misalignments, respectively, and start positions randomly shifted ± 10 mm from a default position. Also, we tested the proposed method with a square peg that was never seen during training. Additional simulation evaluations revealed that using the privileged strategy improved success rates compared to training with only simulated sensor data. Our results demonstrate the advantage of using sim-to-real privileged training for soft robots, which has the potential to alleviate human engineering efforts for robotic assembly. Yuni Fuchioka, Cristian C. Beltran-Hernandez, Masashi Hamaya |
IROS | 2 |
| 2024 | Learning Variable Compliance Control From a Few Demonstrations for Bimanual Robot with Haptic Feedback Teleoperation SystemabstractAutomating 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 causing damage. While compliance control schemes have been introduced to mitigate these issues by controlling forces via external sensors, they are hampered by the need for fine-tuning task-specific controller parameters. Learning from Demonstrations (LfD) offers an intuitive alternative, allowing robots to learn manipulations through observed actions. In this work, we introduce a novel system to enhance the teaching of dexterous, contact-rich manipulations to rigid robots. Our system is twofold: firstly, it incorporates a teleoperation interface utilizing Virtual Reality (VR) controllers, designed to provide an intuitive and cost-effective method for task demonstration with haptic feedback. Secondly, we present Comp-ACT (Compliance Control via Action Chunking with Transformers), a method that leverages the demonstrations to learn variable compliance control from a few demonstrations. Our methods have been validated across various complex contact-rich manipulation tasks using single-arm and bimanual robot setups in simulated and real-world environments, demonstrating the effectiveness of our system in teaching robots dexterous manipulations with enhanced adaptability and safety. Code available at https://github.com/omron-sinicx/CompACT. Tatsuya Kamijo, Cristian C. Beltran-Hernandez, Masashi Hamaya |
IROS | 2 |
| 2024 | Low-Cost Air Hockey Robot Using a Five-Bar Linkage Mechanism Driven by Position-Control ServomotorsabstractIn 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 for such research. Despite the availability of various air hockey robots, their high cost and complexity have limited widespread use among researchers requiring robotics expertise. Addressing this gap, we introduce a low-cost, accessible air hockey robot designed to facilitate HRI studies. Featuring a lightweight five-bar linkage mechanism powered by low-cost servomotors for position control, this robot combines efficiency with ease of use. The complete robot’s cost is estimated at $346.8, with the arm weighing a mere 19 grams. The robot precisely returns the puck by intermittently adjusting its target joint positions, achieving a play with an average return error of 42.6 mm. These characteristics affirm the robot’s potential as a valuable tool for advancing HRI research. Mirai Shinjo, Cristian C. Beltran-Hernandez, Masashi Hamaya, Kazutoshi Tanaka |
IROS | 2 |
| 2023 | Learning Robotic Assembly by Leveraging Physical Softness and Tactile SensingabstractThis study aims to achieve autonomous robotic assembly under uncertain conditions arising from imprecise goal positioning and variations in the angle of the grasped part. Soft robots are suitable for such uncertain and contact-rich environments and are capable of insertion tasks with imprecise goal positions. However, we may also struggle to handle further uncertainty, such as variations in grasping pose. To address the challenge posed by multiple sources of uncertainty, we equipped the soft robot with a tactile sensor. Our key insight is that tactile signal patterns are closely linked to the subtask transitions in an assembly process, specifically from the search to insertion subtasks. We hypothesize soft robots could complete the task by exploring the transition via tactile signals, even in scenarios with imprecise goal positions and grasp misalignment. To this end, we develop an anomaly detection model using a Variational Autoencoder to identify the timing of these transitions. We then employ learning and heuristic-based controllers to navigate the peg tip to the hole and perform the insertion. Our method was validated through real-robot experiments using a soft wrist and a vision-based tactile sensor. The results demonstrate that our method achieves a 100% success rate in scenarios with less uncertain goal pose ($\sigma=2\text{mm}$) and grasp misalignment (up to 5°) and a 70% success rate in scenarios with uncertain goal pose ($\sigma=10\text{mm}$) and grasp misalignment (up to 20°). Moreover, our anomaly detection model can generalize to different peg diameters without additional training. Joaquín Royo-Miquel, Masashi Hamaya, Cristian C. Beltran-Hernandez, Kazutoshi Tanaka |
IROS | 3 |
| 2021 | Robotic Imitation of Human Assembly Skills Using Hybrid Trajectory and Force LearningabstractRobotic assembly tasks involve complex and low-clearance insertion trajectories with varying contact forces at different stages. While the nominal motion trajectory can be easily obtained from human demonstrations through kinesthetic teaching, teleoperation, simulation, among other methods, the force profile is harder to obtain especially when a real robot is unavailable. It is difficult to obtain a realistic force profile in simulation even with physics engines. Such simulated force profiles tend to be unsuitable for the actual robotic assembly due to the reality gap and uncertainty in the assembly process. To address this problem, we present a combined learning-based framework to imitate human assembly skills through hybrid trajectory learning and force learning. The main contribution of this work is the development of a framework that combines hierarchical imitation learning, to learn the nominal motion trajectory, with a reinforcement learning-based force control scheme to learn an optimal force control policy. To further improve the imitation learning part, we develop a hierarchical architecture, following the idea of goal-conditioned imitation learning, to generate the trajectory learning policy on the skill level offline. Through experimental validations, we corroborate that the proposed learning-based framework is robust to uncertainty in the assembly task, can generate high-quality trajectories, and can find suitable force control policies, which adapt to the task’s force requirements more efficiently. Yan Wang 0082, Cristian C. Beltran-Hernandez, Weiwei Wan, Kensuke Harada |
ICRA | 2 |