Article
Computer Science, Information Systems
Muhammad Husnain Haider, Zhonglai Wang, Abdullah Aman Khan, Hub Ali, Hao Zheng, Shaban Usman, Rajesh Kumar, M. Usman Maqbool Bhutta, Pengpeng Zhi
Summary: This paper proposes an adaptive neuro-fuzzy inference system (ANFIS) and global positioning system (GPS) for collision-free navigation of mobile robots. The proposed method automates robot navigation and obstacle avoidance, and controls global path planning and steering using GPS and sensor data fusion. This approach outperforms various state-of-the-art navigation and obstacle avoidance methods in finding an optimal path in unknown environments.
JOURNAL OF KING SAUD UNIVERSITY-COMPUTER AND INFORMATION SCIENCES
(2022)
Article
Computer Science, Information Systems
Rui Sun, Yeying Dai, Qi Cheng
Summary: In order to address the vulnerability issues of the traditional EKF-based GNSS/IMU/Vision fusion scheme to NLOS and multipath contaminated GNSS, as well as low-quality vision measurement, we propose an adaptive weighting strategy. By adjusting the weights of vision and GNSS measurements adaptively based on the chi-square test statistic, the proposed algorithm achieves improved accuracy compared to traditional EKF-based GNSS/IMU fusion and compared EKF-based GNSS/IMU/Vision fusion.
IEEE INTERNET OF THINGS JOURNAL
(2023)
Article
Computer Science, Information Systems
Yong Yuan, You Shi, Song Yue, Shanliang Xue, Changyan Yi, Bing Chen
Summary: In this article, we propose an improved speed obstacle algorithm to address the issue of dynamic obstacle avoidance for AGVs in a dynamic environment. The algorithm estimates the positions of dynamic obstacles using Kalman filtering and builds a speed obstacle buffer based on the estimated positions, allowing the AGV to create a speed obstacle model using the predicted positions for the next moment.
Article
Engineering, Civil
Hongmin Mu, Gang Zhang, Zhe Ma, Mengchu Zhou, Zhengcai Cao
Summary: To assist individuals with visual impairment, a dynamic obstacle avoidance system has been developed using an improved instance segmentation network for high-precision detection. This system enhances the segmentation accuracy of accessible paths for visually impaired users and optimizes exploration efficiency by adopting a bidirectional A* algorithm. Additionally, a collision avoidance algorithm based on regional safety analysis ensures user safety.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Environmental Sciences
Chongyang Han, Weibin Wu, Xiwen Luo, Jiehao Li, Geert Verhoeven
Summary: This paper presents a navigation and obstacle avoidance system for agricultural robots based on LiDAR and a vision camera. The improved clustering algorithm and convex hull algorithm are used to analyze obstacle information in real time. Obstacle avoidance paths and course control methods are developed based on the dangerous zones of obstacles. Through color space analysis and feature analysis, the optimal HSV color component is selected to obtain the ideal vision-guided trajectory images. The proposed algorithm is proven to be effective and robust through obstacle avoidance experiments.
Article
Automation & Control Systems
Christos K. Verginis, Dimos V. Dimarogonas
Summary: This paper addresses the problem of robot motion planning in workspaces with obstacle and uncertain 2nd-order dynamics, combining potential-based feedback controllers with adaptive control techniques. The study is based on sphere world-based configuration spaces and extends the results to arbitrary star-shaped environments, proposing an algorithm for decentralized multi-robot systems. Theoretical findings are verified through extensive simulation results.
Article
Chemistry, Analytical
Kuisong Zheng, Feng Wu, Xiaoping Chen
Summary: This paper presents the development of a laser-based people detection and obstacle avoidance algorithm for a differential-drive robot, addressing the challenges of traditional methods in terms of efficiency and manual data labeling workload.
Article
Chemistry, Multidisciplinary
Yiyang Chen, Chuanxin Cheng, Yueyuan Zhang, Xinlin Li, Lining Sun
Summary: This paper discusses the navigation scenario of mobile robots without global environmental information, proposing a decision-making method based on neural networks that replicates human decision-making process with close to 90% accuracy. The algorithm was validated through experiments in a virtual mobile robot, demonstrating its effectiveness and efficacy.
APPLIED SCIENCES-BASEL
(2022)
Article
Agriculture, Multidisciplinary
Yue Yu, Yufei Liu, Jichun Wang, Noboru Noguchi, Yong He
Summary: This paper introduces a high-performance obstacle avoidance control method based on reinforcement learning for agricultural vehicles. A neural network model is constructed and embedded in the Double DQN architecture to decide the output action according to the input state. Field experiments show that the proposed controller has advantages over traditional methods in terms of space utilization and time efficiency.
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2023)
Article
Engineering, Electrical & Electronic
Danial Sabzevari, Abbas Chatraei
Summary: The study focuses on the estimation accuracy of integrating the inertial navigation system with the global positioning system (GPS), utilizing adaptive and robust structures to overcome environmental disturbances and noises. By comparing different algorithms, the results demonstrate the superiority of the adaptive fuzzy extended Kalman filter (AFEKF) in terms of lower estimation error and higher robustness against disturbances and outliers.
IET RADAR SONAR AND NAVIGATION
(2021)
Article
Engineering, Electrical & Electronic
Amirhossein Ramezanifard, Mojtaba Hashemi, Hassan Salarieh, Aria Alasty
Summary: This study investigates the challenges in autonomous underwater vehicle (AUV) navigation and proposes a method to improve navigation algorithm performance by optimizing gyro output using a robust Kalman filter. Experimental results show that using this method significantly reduces navigation error.
IEEE SENSORS JOURNAL
(2022)
Article
Engineering, Civil
Junqi Zhang, Huan Liu, Peng Zu, Mengshi Zhao, Cheng Wang, Aiiad Albeshri, Abdullah Abusorrah, MengChu Zhou
Summary: Recently, the use of a particle swarm optimizer (PSO) to guide robots in a source location problem has gained attention. Traditional obstacle avoidance strategies are not effective when robots lack prior information. This work proposes a novel PSO based on Tabu Search (PSO-TS) that sets trapping areas as tabu objects to enable robots to locate multiple sources without prior knowledge or expensive hardware.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Computer Science, Artificial Intelligence
Aykut Ozdemir, Seta O. O. Bogosyan
Summary: This paper presents a novel approach, called Gap Based Elastic Trees (GET), which improves the online implementation performance of obstacle avoidance and path planning methods for map-less environments. The GET algorithm combines features of popular algorithms in path planning, obstacle avoidance, and path smoothing, outperforming existing obstacle avoidance approaches and enabling real-time applications of path planners. The improved performance of GET is attributed to its predictive feature and capability to plan ahead. Additionally, the GET method can be adapted for both robotic and autonomous car navigation tasks.
JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS
(2023)
Review
Computer Science, Information Systems
Kai Zhu, Tao Zhang
Summary: This paper discusses the application of Deep Reinforcement Learning (DRL) in mobile robot navigation, compares the relationships and differences between four typical application scenarios, describes the development of DRL-based navigation, and addresses the challenges and possible solutions facing DRL-based navigation.
TSINGHUA SCIENCE AND TECHNOLOGY
(2021)
Article
Agronomy
Yufeng Li, Jingbin Li, Wenhao Zhou, Qingwang Yao, Jing Nie, Xiaochen Qi
Summary: This study proposes a robotic path planning and navigation method based on the improved A* and dynamic window approach algorithms. It can accurately determine the robot's navigation paths, and has high navigation accuracy and stability in specific path navigation.
Article
Thermodynamics
Ashkan Makhsoos, Hossein Mousazadeh, Seyed Saeid Mohtasebi, Mohammadreza Abdollahzadeh, Hamid Jafarbiglu, Elham Omrani, Yousef Salmani, Ali Kiapey
Review
Agriculture, Multidisciplinary
Hamid Jafarbiglu, Alireza Pourreza
Summary: This paper provides a comprehensive review of remote sensing platforms, sensors, applications, and analytic pipelines in the context of nut crops. The findings suggest that the choice of sensor and platform depends on the acreage and purpose of the nut orchards. While various sensors have shown promising results in other crops, they have not been extensively used for nut crops. Accurate sensor calibration is crucial for obtaining repeatable results and enabling temporal and inter-field comparisons. Most remote sensing applications in nut orchards are limited, except for water management, presenting research opportunities. The increasing data size requires the adoption of new machine learning techniques and data fusion frameworks to handle all variables and fill the knowledge gap.
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2022)
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.