論文 - 石上　玄也

Design and Development of Jamming-based Stiffness-Adjustable Wheel on Soft Terrain

Suthisomboon, T., Bonardi, S., Ishigami. G.,

Journal of Terramechanics （PERGAMON-ELSEVIER SCIENCE LTD）  117   101014 (11pages) 2025年

研究論文（学術雑誌）, 共著, 筆頭著者, 責任著者, 査読有り

Tangle- and Contact-free Path Planning for a Tethered Mobile Robot using Deep Reinforcement Learning

Shimada, R., and Ishigami, G.,

Frontiers in Robotics and AI （Frontiers in Robotics and AI）  11   1388634 (13 pages) 2024年09月

研究論文（学術雑誌）, 共著, 筆頭著者, 責任著者, 査読有り

Acoustic Odometry for Wheeled Robots on Loose Sandy Terrain

Andreu Gimenez Bolinches and Genya Ishigami

Proceedings of 13th International Workshop on Robot Motion and Control (RoMoCo2024)    255-260 2024年07月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

Parameter study and identification of DEM modeling for varied sand moisture content based on bulldozing experiment

Sato N., Ishigami G.

Journal of Terramechanics （Journal of Terramechanics）  113-114   100971 (15 pages) 2024年06月

研究論文（学術雑誌）, 共著, 最終著者, 査読有り,  ISSN  00224898

　概要を見る

The discrete element method (DEM) has been widely used to simulate varied sand particles interacting with earthmoving machines. However, past research using DEM barely addressed accurate verification and validation for different sand moisture content. Therefore, the main purpose of this paper is to reveal the range of key parameters of an adhesive force model used in the DEM simulation corresponding to the specific sand moisture content. We considered the bulldozing phenomenon to be typical earthmoving work and performed the bulldozing experiments under different sand moisture levels to investigate the bulldozing force variations. Subsequently, the DEM simulation with an adhesive force model calculated the bulldozing force corresponding to the experimental results. The values for two adhesive parameters, i.e., a scaling magnitude and the maximum adhesive distance between particles, were adjusted such that the maximum bulldozing force calculated in the DEM coincides with that of the experiments under different moisture contents. The experimental verification of the DEM revealed the relationship curves between these two key parameters corresponding to the different moisture content. The relationship obtained in this paper implies that the DEM simulation carefully adjusting the adhesive force parameters can reproduce machine interaction on moist sand environments accurately.

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Perception-and-Energy-aware Motion Planning for UAV using Learning-based Model under Heteroscedastic Uncertainty

Reiya Takemura and Genya Ishigami

Proceedings of the 2024 IEEE International Conference on Robotics and Automation (ICRA 2024)     pp. 10103-10109 2024年05月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

Accurate Rover Mobility Analysis Using HILS-DRFT with Real-Time Parameter Tuning Approach

Takahiro Fuke, Sora Ishikawa and Genya Ishigami

Proceedings of the 21st International and 12th Asia-Pacific Regional Conference of the International Society for Terrain-Vehicle Systems 2024年01月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

DEM-Based Analysis and Optimization of Excavation Bucket Drum for In-Situ Resource Utilization

Tomoyasu Nakano, Takuya Omura and Genya Ishigami

Proceedings of the 21st International and 12th Asia-Pacific Regional Conference of the International Society for Terrain-Vehicle Systems 2024年01月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

Collaborative Robot Systems for Lunar Landing Pad Construction

Kenji Nagaoka, Genya Ishigami, Munetaka Ueno, Keiji Nagatani

Proc. of the AROB-ISBC-SWARM 2024    pp. 985-986 2024年01月

研究論文（国際会議プロシーディングス）, 共著, 査読有り

Granular Flow in Reduced Gravity: Analysis and Insights from Centrifuge Experiments at the International Space Station

Takuya Omura and Genya Ishigami

Proceedings of the 21st International and 12th Asia-Pacific Regional Conference of the International Society for Terrain-Vehicle Systems 2024年01月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

車輪ロボットの移動性能を可視化する可操縦性楕円体の提案

上田凌，石上玄也

日本ロボット学会誌 （一般社団法人 日本ロボット学会）  2024年

研究論文（学術雑誌）, 共著, 最終著者, 査読有り

車輪ロボットの移動性能を可視化する可操縦性楕円体の提案

後藤優輝，石上玄也

日本ロボット学会誌 （一般社団法人 日本ロボット学会）  2024年

研究論文（学術雑誌）, 共著, 最終著者, 査読有り

Modeling of slip rate-dependent traversability for path planning of wheeled mobile robot in sandy terrain

Sakayori G., Ishigami G.

Frontiers in Robotics and AI （Frontiers in Robotics and AI）  11   1320261 (16 pages) 2024年

研究論文（学術雑誌）, 共著, 最終著者, 査読有り,  ISSN  2296-9144

　概要を見る

2 : 共著

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水分を含む土質におけるクローラの個別要素法を用いた走行力学解析

柳川 拓輝, 石上 玄也

日本ロボット学会誌 （一般社団法人 日本ロボット学会）  42 （ 4 ） 406 - 409 2024年

研究論文（学術雑誌）, 共著, 最終著者, 査読有り,  ISSN  02891824

　概要を見る

<p>Tracked vehicles has been widely used in unstructured environments such as on uneven/deformable terrains. The mobility of the track unit consisting of interconnected metal plates is the key to enhance the safety of the vehicle. This study focuses on the track and soil interaction, particularly the wetted soil. The Distinct Element Method is applied for analyzing the interaction stress between the track and soil with varied moisture content and slip ratio. The analysis revealed that the significant stress is generated to the leading edge of the track unit and the stress distribution shifts toward the rear region of the track in moist soil. </p>

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Granular flow experiment using artificial gravity generator at International Space Station

Ozaki S., Ishigami G., Otsuki M., Miyamoto H., Wada K., Watanabe Y., Nishino T., Kojima H., Soda K., Nakao Y., Sutoh M., Maeda T., Kobayashi T.

npj Microgravity （npj Microgravity）  9 （ 1 ） 61 (13 pages) 2023年12月

研究論文（学術雑誌）, 共著, 査読有り

　概要を見る

Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

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移動ロボットによる月面土質計測を目的とした調査経路生成手法の提案

新井 康平, 石上 玄也

日本ロボット学会誌 （一般社団法人 日本ロボット学会）  41 （ 9 ） 813 - 816 2023年11月

研究論文（学術雑誌）, 最終著者, 査読有り,  ISSN  02891824

　概要を見る

<p>A lunar landing base is a key infrastructure for mass transportation from Earth to the Moon and for sustainable activities on the Moon in the future. Unmanned robots are expected to survey the soil stiffness of multiple points for securely constructing the landing infrastructure. There is a trade-off between the time or energy required for the survey, the number of survey points, and the completeness of the survey. This paper proposes a path planning for robotic soil investigation that determines the location and the number of additional survey points. The proposed method aims to obtain completeness of information related to the soil stiffness as well as to reduce the survey time. The simulation study reveals that the method achieves obtaining a certain level of completeness while it reduces the time required for the survey. </p>

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Experimental analysis on jumping mechanism using snap-through buckling of an elastic strip

Shuhei Shimizu, Takara Abe, Tomohiko G. Sano, Genya Ishigami

IUTAM Symposium on Nonlinear dynamics for design of mechanical systems across different length/time scales    PS08, (2 pages) 2023年09月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

UV laser etching process: enhancing bending performance in ionic polymer-metal composites (IPMC)

N. Furusawa, K. Soda, N. Matsuhisa, G. Ishigami, J. Ogawa, M. Asai and H. Takahashi

Proc. of the 14th Japan-China-Korea Joint Conference on MEMS/NEMS 2023    2023-P-022 (2 pages) 2023年09月

研究論文（国際会議プロシーディングス）, 共著

Jumping mechanism of elastic shells on rigid or granular substrates

Takara Abe, Shuhei Shimizu, Genya Ishigami, Tomohiko G. Sano

IUTAM Symposium on Nonlinear dynamics for design of mechanical systems across different length/time scales    PS07, (2 pages) 2023年09月

研究論文（国際会議プロシーディングス）, 共著, 査読有り

Path Planning with Cable-obstacles Avoidance for a Tethered Mobile Robot in Unstructured Environments

Ryuki Shimada and Genya Ishigami

Proceedings of the 34th International Symposium on Space Technology and Science (ISTS 2023)    2023-k-04, (8 pages) 2023年08月

研究論文（国際会議プロシーディングス）, 共著, 最終著者, 査読有り

Energy-and-perception-aware planning and navigation framework for unmanned aerial vehicles

Takemura R., Aoki N., Ishigami G.

Advances in Mechanical Engineering （Advances in Mechanical Engineering）  15 （ 4 ） 1 - 17 2023年04月

研究論文（学術雑誌）, 共著, 最終著者, 査読有り,  ISSN  16878132

　概要を見る

This paper presents an energy and perception aware framework for path planning and navigation of unmanned aerial vehicles (UAVs) in GNSS-denied and spatiotemporal wind environments. The proposed framework mainly consists of the global and local path planning methods that respectively consider the energy consumption of an UAV and perception quality of a light detection and ranging (LiDAR) sensor mounted on the UAV. The energy consumption is estimated based on the aerodynamic model that calculates drag and lift forces on the UAV. The global planner then uses the total energy consumption in the spatiotemporal wind as the cost function to find an energy-efficient path as a set of waypoints. The local path planning navigates the UAV between the waypoints with maintaining the perception quality. The perception quality is quantified based on how well the LiDAR sensor scans feature points around the UAV that highly correlates with the navigation accuracy. Numerical simulation study for each of the global and local path planners validates their usefulness. Further, the overall framework is entirely verified in a long-range flight scenario of the photorealistic environments developed in the Gazebo simulation.

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