研究者詳細 - 石井　和男

論文 - 石井　和男

分割表示506 件中 21 - 40 件目／全件表示 >>

Evaluating of Tree Branch Recognition Algorithm in Pruning Robots under Augmented Environmental Conditions 査読有り国際誌

Albaroudi M., Alahmad R., Alraee A., Ishii K.

Proceedings of International Conference on Artificial Life and Robotics 356 - 360 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Integrating service robots has revolutionized several sectors, by enhancing accuracy, efficiency, and scalability. Those robots are crucial in automating labor-intensive processes such as tree pruning, where accurate branch detection is vital. This research evaluates the performance of YOLOv8-seg model for recognizing tree branches as a step towards fully autonomous pruning. To address the challenges posed by diverse and complex real-world conditions, video sequences are augmented using techniques that simulate environmental variations, such as changes in brightness, contrast, and Gaussian noise. The evaluation metrics including the number of true detections, number of false detections, and precision, demonstrate robust and accurate branch perception under real-world conditions. These results highlight the potential of YOLOv8-seg to improve pruning systems, paving the way for scalable, efficient, and accurate robotic solutions in tree maintenance.

Scopus

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Practical Exercise on An Autonomous Driving System Using Mobile Devices and IoT Devices for An Agricultural Tractor 査読有り国際誌

Katayama D., Nakazuru Y., Sato H., Masuda S., Nishida Y., Yasukawa S., Ishii K.

Proceedings of International Conference on Artificial Life and Robotics 342 - 346 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The current method of agriculture is expected to make sustainable production difficult due to the effects of a declining and aging workforce. To solve these issues, research and development of smart agriculture technologies, including automated tractor operation, have been underway. We have developed an autonomous driving system for a commercially mini-tractor using mobile and IoT devices to more facilitate the introduction of automated driving technology for tractors. In addition, the exercise was conducted for students to implement and operate this system with an aim of education for robotics engineers. This exercise consists of lectures and development exercises for the system. The demonstration results showed that the students' difficulty level was able to set appropriate difficulty. The results of the rubric also showed that the students improved their proficiency in the algorithms and programming of applications that are fundamental to autonomous driving systems.

Scopus

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Proposal of a Method for Acquiring Characteristics of Large-Diameter Solenoids 査読有り国際誌

Tominaga M., Tominaga A., Takemura Y., Ishii K.

Lecture Notes in Computer Science 15570 LNAI 200 - 211 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The solenoids used in the RoboCup soccer middle-sized league are large-diameter push solenoids, which are not widely available in the market as a product. Therefore, the relationship between input and output can only be obtained through experiments by researchers who have manufactured the solenoids. Until now, simulations have been performed using FEM and other methods, but it was not possible to analyze the actual plunger motion. In this study, the motion of a plunger is observed using an actual solenoid, and the input-output relationship is clarified. This will allow us to clarify the equation relating ball flight distance and self-inductance as an actual ball ejection device. This research can be utilized not only for Robocup but also for the injection mechanism of Elide Fire Ball and inexpensive and compact ball ejector.

DOI： 10.1007/978-3-031-85859-8_17

Scopus

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Visual-Based System for Fish Detection and Velocity Estimation in Marine Aquaculture 査読有り国際誌

Alahmad R., Solpico D., Masuda S., Ishizuka T., Naramura K., Dong Z., Li Z., Nishida Y., Ishii K.

Proceedings of International Conference on Artificial Life and Robotics 351 - 355 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

As global aquaculture continues to expand to meet the rising seafood demand, optimization of feeding remains a crucial issue for the industry to address to achieve sustainable development. This study proposed a visual-based system for estimating fish velocity, which is to be integrated into a farmer's feeding operation to determine the optimal feed amount. The YOLOv8 algorithm was utilized to detect fish in underwater videos, enabling precise monitoring of fish behavior. The results indicate a successful fish detection with an accuracy of 85%. The fish velocity estimation approach demonstrated the difference between the hungry fish and the normal fish behavior. The findings suggested that integrating fish velocity data into feeding operations can significantly enhance feed efficiency, reduce waste, and promote sustainable aquaculture practices, ensuring optimal fish growth while minimizing environmental and economic impacts.

Scopus

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Underwater Frequency Selection Algorithm Based on the Received Signal 査読有り国際誌

Alahmad R., Albaroudi M., Alraee A., Ishii K.

2025 IEEE Underwater Technology Ut 2025 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Underwater communication is widely regarded as one of the most significant challenges due to the unique physical properties of water. Among the available communication methods, radiofrequency communication offers higher data transmission rates than acoustic communication. However, higher frequencies suffer from substantial attenuation in water, making it difficult to achieve long-distance transmission. Addressing the tradeoff between transmission rate and communication distance is essential for achieving optimal performance. Unlike conventional systems that rely on fixed operating frequencies, this study introduces a dynamic frequency selection algorithm. This algorithm dynamically adjusts the operating frequency in real-time based on channel conditions and transmission rate feedback, ensuring a more adaptive and efficient communication system. To validate this approach, a dipole antenna with multiple impedance matching was designed and tested in a water tank environment. The experimental results revealed that bandwidth performance varied across different frequencies. Transmission rate analysis showed that higher frequencies provided higher data transmission over short distances. Conversely, lower frequencies exhibited better signal stability and reliability for long-distance communication due to their reduced attenuation. These findings highlight the importance of adaptive frequency selection in underwater radiofrequency communication, where a balance between transmission rate and communication distance must be achieved to support various operational requirements.

DOI： 10.1109/UT61067.2025.10947386

Scopus

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Realizing Variable Stiffness through Structures Designed for Quick Motion 査読有り国際誌

Suzuki Katsuaki, Nishida Yuya, Ishii Kazuo

Journal of Advances in Artificial Life Robotics ( 株式会社 ALife Robotics ) 4 ( 3 ) 122 - 127 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

To expand a robot’s range of activities, we aim to realize three functions: normal motion, quick
motion, and variable stiffness. In this study, we developed a method for realizing variable stiffness
using a joint mechanism that can achieve normal and quick motions. Our analysis results
confirmed that stiffness could be changed by adjusting the initial displacement of the spring
incorporated in the joint mechanism. Furthermore, we manufactured a machine containing the
proposed mechanism and evaluated the proposed method by comparing our theoretical and
experimental results considering errors. Our findings showed similar trends between the measured
and theoretical values with an error caused by friction between machine components.

DOI： 10.57417/jaalr.4.3_122

CiNii Research

Kinematics and Simulation for Mobil Robot Adapted Three Omni Rollers 査読有り国際誌

Kimura Kenji, Nakayama Kazuki, Suzuki Katsuaki, Ishii Kazuo

Journal of Robotics, Networking and Artificial Life ( 一般社団法人　ロボット人工生命学会 ) 11 ( 2 ) 134 - 138 2025年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

Mobile robots are expected to play an active role in the logistics industry, and their development is underway. There are many examples of mechanisms with three omni-rollers as omnidirectional mobile mechanisms, and methods for analyzing and verifying their kinematics have been proposed. In this study, we derive a robot trajectory equation for roller drive. In addition, we verified the kinematics in a simulation environment on a PC, with the goal of reducing costs and time in a simple verification experiment with good visibility.

DOI： 10.57417/jrnal.11.2_134

CiNii Research

オンライン講義を導入した水中ロボット競技会の開催査読有り

佐藤雅紀, 松尾貴之, 小澤正宜, 有馬正和, 石井和男

工学教育研究講演会講演論文集 ( 公益社団法人日本工学教育協会 ) 2024 ( 0 ) 416 - 417 2024年11月

Performance Analysis of Underwater Radiofrequency Communication in Seawater: An Experimental Study 査読有り国際誌

Alahmad R., Alraie H., Hasaba R., Eguchi K., Matsushima T., Fukumoto Y., Ishii K.

Journal of Marine Science and Engineering 12 ( 11 ) 2024年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Communication with the underwater vehicles during their tasks is one of the most important issues. The need for real-time data transfer raises the necessity of developing communication systems. Conventional underwater communication systems, such as acoustic systems, cannot satisfy applications that need a high transmission data rate. In this study, we investigate the radio frequency communication system in seawater, which is crucial for real-time data transfer with underwater vehicles. The experiments were in a water tank full of seawater and a real environment in the ocean. Three types of antennae were used: loop antenna, wire antenna, and helical antenna. An Autonomous Underwater Vehicle (AUV) is used as a transmitter to measure the transmission rate as a function of distance. The helical antenna showed better performance regarding the coverage area. Furthermore, the AUV could move freely within the helical and capture live video streaming successfully. This investigation underscores the potential of radio frequency communication systems for enhancing underwater vehicle operations, offering promising avenues for future research and practical implementation.

DOI： 10.3390/jmse12112104

Scopus

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Wavelet OFDM Wireless Communication System for Autonomous Underwater Vehicles Using Loop-Shaped Antennas in Underwater Environments 査読有り国際誌

Hasaba R., Eguchi K., Wakisaka T., Hirokawa J., Hirose M., Matsushima T., Fukumoto Y., Nishida Y., Ishii K.

IEEE Access 12 129633 - 129645 2024年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

The manuscript introduces a radio wave-based wireless communication system tailored for Autonomous Underwater Vehicles (AUVs), optimized for underwater deployment. Initial experiments to ascertain the fundamental properties of a loop antenna were conducted in a small-scale water tank, followed by comprehensive communication and video transmission trials in a larger tank with an AUV. A specialized waterproof enclosure was developed to house a waterproof antenna, a Vector Network Analyzer (VNA), and a communication board. This setup facilitated the evaluation of the loop antenna's radio propagation attributes and the identification of frequencies conducive to underwater communication. Designed with practical deployment in mind, the system incorporates a 2-meter loop antenna for signal transmission and a 0.5m by 0.8m rectangular loop antenna integrated into the AUV for signal reception. Utilizing a wavelet Orthogonal Frequency Division Multiplexing (OFDM) communication board and tuning to lower frequencies, the system successfully established User Datagram Protocol (UDP) and Transfer Control Protocol (TCP) communications within a few meter radius from the transmitting antenna, achieving data transfer rates up to 6.8 Mbps.

DOI： 10.1109/ACCESS.2024.3457508

Scopus

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General Kinematics and Simulation for Mobile Robot Adapted Three Unconstraint Rollers 査読有り国際誌

Kimura K., Ishii K.

International Conference on Electrical, Computer, and Energy Technologies, ICECET 2024 2024年07月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In recent years, efficient mobility is required for omni-directional mobile robots in the logistics industry. There are various types of rollers mounted on mobile robots. Among them, omni-directional rollers (omni roller) are considered to have excellent omni-directional mobility and easy control. Assuming a circular mechanism, kinematics has been derived assuming an arbitrary arrangement along this circumference, and several studies have evaluated roller arrangements in terms of the speed efficiency of the driving rollers. To evaluate the roller arrangement, kinematics is necessary, in which not only the contact position of the rollers but also the direction is a parameter. In this study, kinematics is derived for a mobile robot equipped with three omni-rollers, with the contact position and direction of the rollers as parameters, and the behaviors of the roller velocity is investigated for the robot's movement in all directions.

DOI： 10.1109/ICECET61485.2024.10698134

Scopus

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The Method of Verification of Sphere Kinematics by Two Mouse Image Sensors 査読有り国際誌

Kimura K., Ishii K.

International Conference on Electrical, Computer, and Energy Technologies, ICECET 2024 2024年07月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In the past, omni-directional wheels, including omni-rollers, have been studied. The sphere has attracted attention as a shape with better running and overweight characteristics than this. Because of its excellent symmetry, it has been used as a wheel in omni-directional moving mechanisms. Spherical robots driven by two constrained rollers have been studied extensively, not only to derive their kinematics but also to study their validation methods. In this study, we propose a new method for verifying sphere kinematics, in which the rotational motion of spheres driving two rollers by two mouse sensors and used for estimation calculations.

DOI： 10.1109/ICECET61485.2024.10698436

Scopus

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Development of a Jellyfish Removal Device to Equip on Underwater Robot and Its Suction Performance Evaluation 査読有り国際誌

Masuda S., Ahn J., Ishii K.

Oceans Conference Record (IEEE) 2024年04月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In recent years, massive blooms of jellyfish have occurred due to the influence of rising water temperatures, causing damage to industries such as fisheries. To reduce the damage caused by jellyfish, fishermen conduct jellyfish removal work, however, it cannot be said to be efficient from a cost perspective. As one of the efficient methods, our research team is proposing an underwater robot-based jellyfish removal work. Our research team has developed a small-size underwater robot to test, and with the assistance of the fisheries workers, conducted jellyfish removal tests in the Seto Inland Sea in August 2022. Through this test, we confirmed that jellyfish removal using underwater robots is feasible, and based on the results of the test, we improved the jellyfish removal device. In this paper, we introduce the improved jellyfish removal devices, that we have developed, and then evaluate the performance of this device. In the results of the performance evaluation, compared to the test type device, the improved device showed a suction range that was 2.77 times wider, and the flow velocity increased by 2.28 times.

DOI： 10.1109/OCEANS51537.2024.10682331

Scopus

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Double the data rate in underwater acoustic communication using OFDM based on subcarrier power modulation 査読有り国際誌

Alraie H., Alahmad R., Ishii K.

Journal of Marine Science and Technology (Japan) 29 ( 2 ) 457 - 470 2024年02月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

Underwater communication is one of the most important and difficult challenges facing researchers due to the high attenuation of the signal, communication with the surface because of the harsh medium of water, and data transmission performance degradation as a result of various effects. Underwater acoustic communication (UWA) has a low data rate, which describes the disadvantage of this type of communication. In addition, it has a low bandwidth range and high latency but has a long transmission range as an advantage. Multicarrier wireless transmission systems increase the data rate by sending the data using more than one carrier. We proposed a noncoherent orthogonal frequency division multiplexing (OFDM) method to increase the data rate in UWA communication systems. In addition, doubling the data rate in the OFDM using Subcarrier Power Modulation (OFDM-SPM) system can save half of the bandwidth. The MATLAB simulation program was used to implement the system in the underwater acoustic environment to increase its throughput. The proposed design uses Differential Phase Shift Keying (DPSK) with power control, and the data stream is transmitted through two-dimensional modulation schemes, the DPSK, and the power level of each subcarrier in the OFDM system with cyclic prefix (CP). The underwater channel was designed using a Rician fading multipath with a spreading loss formula as a function of distance and frequency. We designed an equalizer at the receiver side to recover the original signal as a function of three parameters which are: the channel effect as a rate between transmitting and receiving symbols, the Rician channel response, and the UWA spreading loss. OFDM-Subcarrier Power Modulation (OFDM-SPM) using the proposed equalizer performed better than the theoretical OFDM-SPM in the Rayleigh channel. The designed equalizer increased the performance of the OFDM-SPM system by 25% which helped to enhance the system’s throughput and doubled the data rate compared with the OFDM system, doubling the data rate using OFDM-SPM had been validated in laboratory experiments in the Time domain.

DOI： 10.1007/s00773-024-00989-2

Scopus

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Optimization method to improve visual SLAM in dynamic environment 査読有り国際誌

Liu Yufei, Ishii Kazuo

人工生命とロボットに関する国際会議予稿集 ( 株式会社ALife Robotics ) 29 590 - 593 2024年02月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Aiming at the problem that the robustness of the classic visual SLAM system is greatly affected by dynamic target feature points in the environment, a method is proposed to use a target detection algorithm to identify and eliminate dynamic target feature points. First, use the target detection algorithm YOLOv5 to identify the collected environmental images, and select the surrounding environment. Objects identified as dynamic targets in the environment, and then the target detection results are integrated into the feature extraction of the visual SLAM frontend, the feature points belonging to the dynamic target part of the extracted image feature points are removed, and the remaining static feature points are used to map Construction and positioning, and finally testing on the TUM data set. The results show that after using the target detection algorithm to eliminate dynamic feature points, the root mean square error of the absolute trajectory error of the visual SLAM system in highly dynamic scenes is reduced by 97.89%, effectively improving the positioning accuracy and robustness of the system.

DOI： 10.5954/icarob.2024.os20-3

CiNii Research

Gakken Hills Interdisciplinary Ekiden Competing with Humans, Animals, and Robots 査読有り国際誌

Fujinaga Takuya, Tominaga Moeko, Katayama Daigo, Ishii Kazuo

人工生命とロボットに関する国際会議予稿集 ( 株式会社ALife Robotics ) 29 638 - 641 2024年02月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The number of robots exiting in human living spaces has increased, and interaction between humans and robots has become an important issue. The purpose of this study is to propose a future society where humans, animals, and robots coexist. We organize relay race, or ekiden in Japanese, where they compete together as runners. The competition rules have been established to ensure that each runner can compete fairly. This paper explains the competition rules and discuss the fairness of the rules

DOI： 10.5954/icarob.2024.os20-14

CiNii Research

Development of antagonistic wire-driven joint mechanism capable of rapid motion and variable stiffness 査読有り国際誌

Suzuki Katsuaki, Nishida Yuya, Ishii Kazuo

人工生命とロボットに関する国際会議予稿集 ( 株式会社ALife Robotics ) 29 634 - 637 2024年02月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

The advancement of digital transformation in manufacturing is expected to demand novel tasks for industrial machinery unlike before. When adding mechanisms or actuators to enhance machine functionality, concerns arise about potential system enlargement and increased complexity. The design concept of integrating multiple functions into mechanisms using a few actuators and components serves as one means to address these issues. We aim to elucidate the structural arrangement capable of achieving three functions, including normal motion, rapid motion, and variable stiffness, using two electric actuators. In this paper, we introduce a newly devised antagonistic wiredriven joint mechanism aimed at improving the variable stiffness function within the articulated mechanism we have developed, enabling three functionalities.

DOI： 10.5954/icarob.2024.os20-13

CiNii Research

Design of flexible mechanism for flexible manipulator 査読有り国際誌

Huang Jiawei, Ishii Kazuo

人工生命とロボットに関する国際会議予稿集 ( 株式会社ALife Robotics ) 29 594 - 598 2024年02月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Based on the study of the kinematic limitations of the rigid manipulator structure and the characteristics of the existing flexible manipulator in different categories, this paper proposes a structure assumption of flexible manipulator based on the advantages of high load of rigid joint and high flexibility of flexible manipulator. This paper designed a flexible manipulator structure driven by wires. Using the forward kinematics analysis, the sport model of the structure. The motion range of the end of the manipulator arm and the length changes of the wires were simulated with the movement of the model.

DOI： 10.5954/icarob.2024.os20-4

CiNii Research

Mandarin Orange Anomaly Detection with Cycle-GAN 査読有り国際誌

Noguchi K., Takemura Y., Tominaga M., Ishii K.

2024 IEEE/SICE International Symposium on System Integration, SII 2024 644 - 649 2024年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In the agricultural field, many issues arose such as the decline of productivity due to population aging and the lack of new generations to replace the previous ones. Information and communication technology (ICT), the Internet of Things (IoT), and robotics are expected to provide solutions. Despite the enormous promise of these technologies, they are expensive to implement, require ongoing technical assistance, and have little affinity for the immediate demands of farmers. For example, when a new breed is improved, it is necessary to ask the developing company to outsource data analysis to identify defective new individuals. Therefore, the main objective of this study is to realize an economically viable and easily implementable smart agricultural system. For this purpose, interviews were conducted with actual farmers, and it became clear that even in the fruit sorting process, which is becoming increasingly automated, the burden on farmers with knowledge and skills is significant. In this study, we focus on mandarin oranges, which have the highest yield among Japanese oranges, to automate the identification of defective fruit, i. e. damaged or affected by a disease, which has been done by the human eye. In this study, an automatic fruit sorting system based on a conveyor belt mechanism was designed. The system performs fruit sorting using a CNN based on individual features derived from images, but since the number of images of defective individuals is far fewer than the number of images of good individuals, the system was supplemented by a Cycle-GAN. This integrated approach aims to alleviate labor intensity and enhance operational efficiency, thereby contributing to the promotion of smart agriculture.

DOI： 10.1109/SII58957.2024.10417370

Scopus

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Energy Consumption of a Wheel/Track Reconfigurable Mobile Robot on the Farm 査読有り国際誌

Kamon S., Di Maria E., Alahmad R., Irmiya I.R., Puwei S., Giannocaro N.I., Ishii K.

2024 IEEE/SICE International Symposium on System Integration, SII 2024 798 - 803 2024年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents the experimental results of energy consumption of a wheel/track reconfigurable mobile robot which has been developed for maintenance of vineyard. According to the Bekker's soil model, the wheel rolling resistance depends on the sinkage to the ground, so that the mobile mechanism consists of 2 rear wheels and 2 front tracks which is designed to lift up and down and control the contact area to the ground and to switch the modes based on the soil conditions to minimize energy consumption. The wheel mode is supposed to be operated for the firm soil where the front tracks are lifted up to decrease the contact area, and the track mode is for the soft soil where the front tracks push down the ground and increase the contact area and decrease sinkage. In the experiment, we compared the energy consumption between the wheel mode and the track mode in firm, soft, and wet soil conditions.

DOI： 10.1109/SII58957.2024.10417300

Scopus

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