2,499 results on '"Mobile Robots"'
Search Results
2. An Adaptive and Automatic Power Supply Distribution System with Active Landmarks for Autonomous Mobile Robots.
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Li, Zhen, Gao, Yuliang, Zhu, Miaomiao, Tang, Haonan, and Zhang, Lifeng
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INDUSTRIAL robots , *MOBILE robot control systems , *MOBILE robots , *POWER resources , *LABOR market , *AUTONOMOUS robots - Abstract
With the development of automation and intelligent technologies, the demand for autonomous mobile robots in the industry has surged to alleviate labor-intensive tasks and mitigate labor shortages. However, conventional industrial mobile robots' route-tracking algorithms typically rely on passive markers, leading to issues such as inflexibility in changing routes and high deployment costs. To address these challenges, this study proposes a novel approach utilizing active landmarks—battery-powered luminous landmarks that enable robots to recognize and adapt to flexible navigation requirements. However, the reliance on batteries necessitates frequent recharging, prompting the development of an automatic power supply system. This system integrates omnidirectional contact electrodes on mobile robots, allowing to recharge active landmarks without precise positional alignment. Despite these advancements, challenges such as the large size of electrodes and non-adaptive battery charging across landmarks persist, affecting system efficiency. To mitigate these issues, this research focuses on miniaturizing active landmarks and optimizing power distribution among landmarks. The experimental results of this study demonstrated the effectiveness of our automatic power supply method and the high accuracy of landmark detection. Our power distribution calculation method can adaptively manage energy distribution, improving the system's persistence by nearly three times. This study aims to enhance the practicality and efficiency of mobile robot remote control systems utilizing active landmarks by simplifying installation processes and extending operational durations with adaptive and automatic power supply distribution. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Learning Autonomous Navigation in Unmapped and Unknown Environments.
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He, Naifeng, Yang, Zhong, Bu, Chunguang, Fan, Xiaoliang, Wu, Jiying, Sui, Yaoyu, and Que, Wenqiang
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AUTONOMOUS robots , *ACQUISITION of data , *PRIOR learning , *MOBILE robots , *ALGORITHMS , *NAVIGATION - Abstract
Autonomous decision-making is a hallmark of intelligent mobile robots and an essential element of autonomous navigation. The challenge is to enable mobile robots to complete autonomous navigation tasks in environments with mapless or low-precision maps, relying solely on low-precision sensors. To address this, we have proposed an innovative autonomous navigation algorithm called PEEMEF-DARC. This algorithm consists of three parts: Double Actors Regularized Critics (DARC), a priority-based excellence experience data collection mechanism, and a multi-source experience fusion strategy mechanism. The algorithm is capable of performing autonomous navigation tasks in unmapped and unknown environments without maps or prior knowledge. This algorithm enables autonomous navigation in unmapped and unknown environments without the need for maps or prior knowledge. Our enhanced algorithm improves the agent's exploration capabilities and utilizes regularization to mitigate the overestimation of state-action values. Additionally, the priority-based excellence experience data collection module and the multi-source experience fusion strategy module significantly reduce training time. Experimental results demonstrate that the proposed method excels in navigating the unmapped and unknown, achieving effective navigation without relying on maps or precise localization. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Intelligent Control System for Brain-Controlled Mobile Robot Using Self-Learning Neuro-Fuzzy Approach.
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Razzaq, Zahid, Brahimi, Nihad, Rehman, Hafiz Zia Ur, and Khan, Zeashan Hameed
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MOBILE robot control systems , *INTELLIGENT control systems , *ROBOT control systems , *BRAIN-computer interfaces , *AUTODIDACTICISM , *MOBILE robots - Abstract
Brain-computer interface (BCI) provides direct communication and control between the human brain and physical devices. It is achieved by converting EEG signals into control commands. Such interfaces have significantly improved the lives of disabled individuals suffering from neurological disorders—such as stroke, amyotrophic lateral sclerosis (ALS), and spinal cord injury—by extending their movement range and thereby promoting self-independence. Brain-controlled mobile robots, however, often face challenges in safety and control performance due to the inherent limitations of BCIs. This paper proposes a shared control scheme for brain-controlled mobile robots by utilizing fuzzy logic to enhance safety, control performance, and robustness. The proposed scheme is developed by combining a self-learning neuro-fuzzy (SLNF) controller with an obstacle avoidance controller (OAC). The SLNF controller robustly tracks the user's intentions, and the OAC ensures the safety of the mobile robot following the BCI commands. Furthermore, SLNF is a model-free controller that can learn as well as update its parameters online, diminishing the effect of disturbances. The experimental results prove the efficacy and robustness of the proposed SLNF controller including a higher task completion rate of 94.29% (compared to 79.29%, and 92.86% for Direct BCI and Fuzzy-PID, respectively), a shorter average task completion time of 85.31 s (compared to 92.01 s and 86.16 s for Direct BCI and Fuzzy-PID, respectively), and reduced settling time and overshoot. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Path Planning Based on Artificial Potential Field with an Enhanced Virtual Hill Algorithm.
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Lee, Hyun Jeong, Kim, Moon-Sik, and Lee, Min Cheol
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ROBOT motion ,ROBOTS ,ALGORITHMS ,ROBOTICS ,MOBILE robots - Abstract
The artificial potential field algorithm has been widely applied to mobile robots and robotic arms due to its advantage of enabling simple and efficient path planning in unknown environments. However, solving the local minimum problem is an essential task and is still being studied. Among current methods, the technique using the virtual hill concept is reliable and suitable for real-time path planning because it does not create a new local minimum and provides lower complexity. However, in the previous study, the shape of the obstacles was not considered in determining the robot's direction at the moment it is trapped in a local minimum. For this reason, longer or blocked paths are sometimes selected. In this study, we propose an enhanced virtual hill algorithm to reduce errors in selecting the driving direction and improve the efficiency of robot movement. In the local minimum area, a dead-end algorithm is also proposed that allows the robot to return without entering deeply when it encounters a dead end. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Design, Experiments, and Path Planning for a Lightweight 3D Minimally Actuated Serial Robot with a Mobile Actuator.
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Bitton, Or, Cohen, Avi, and Zarrouk, David
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OPTIMIZATION algorithms ,ROBOTIC path planning ,MINIMAL design ,ROBOTS ,ACTUATORS ,MOBILE robots - Abstract
This paper presents a novel three-dimensional (3D) minimally actuated serial robot (MASR) and its unique kinematic analysis. Unlike traditional robots, the 3D MASR features a passive arm devoid of wires or motors, comprising passive rotational and prismatic joints. A single mobile actuator (MA) traverses the arm, engages designated joints for operation, and locks them in place with a worm gear setup. A gripper is attached to the MA, enabling object transportation along the arm, reducing joint actuation, and optimizing task completion time. Our key contributions include the mechanical design, and in particular the robot's passive joints with their automated actuation mechanism, and a novel optimization algorithm leveraging neural networks (NNs) to minimize task completion time through advanced kinematic analysis. Experiments with a physical prototype of the 3D MASR demonstrate its major advantages: it is remarkably lightweight (2.3 kg for a 1 m long arm and a 1 kg payload) compared to similar robots; it is highly modular (five joints R and P actuated by a single MA); and part replacement is effortless due to the absence of wiring along the arm. These features are visually depicted in the accompanying video. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Multi-Strategy Improved Harris Hawk Optimization Algorithm and Its Application in Path Planning.
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Tang, Chaoli, Li, Wenyan, Han, Tao, Yu, Lu, and Cui, Tao
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OPTIMIZATION algorithms , *ROBOTIC path planning , *DUNG beetles , *SEARCH algorithms , *MOBILE robots , *ALGORITHMS , *POTENTIAL field method (Robotics) - Abstract
Path planning is a key problem in the autonomous navigation of mobile robots and a research hotspot in the field of robotics. Harris Hawk Optimization (HHO) faces challenges such as low solution accuracy and a slow convergence speed, and it easy falls into local optimization in path planning applications. For this reason, this paper proposes a Multi-strategy Improved Harris Hawk Optimization (MIHHO) algorithm. First, the double adaptive weight strategy is used to enhance the search capability of the algorithm to significantly improve the convergence accuracy and speed of path planning; second, the Dimension Learning-based Hunting (DLH) search strategy is introduced to effectively balance exploration and exploitation while maintaining the diversity of the population; and then, Position update strategy based on Dung Beetle Optimizer algorithm is proposed to reduce the algorithm's possibility of falling into local optimal solutions during path planning. The experimental results of the comparison of the test functions show that the MIHHO algorithm is ranked first in terms of performance, with significant improvements in optimization seeking ability, convergence speed, and stability. Finally, MIHHO is applied to robot path planning, and the test results show that in four environments with different complexities and scales, the average path lengths of MIHHO are improved by 1.99%, 14.45%, 4.52%, and 9.19% compared to HHO, respectively. These results indicate that MIHHO has significant performance advantages in path planning tasks and helps to improve the path planning efficiency and accuracy of mobile robots. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Optimizing Orchard Planting Efficiency with a GIS-Integrated Autonomous Soil-Drilling Robot.
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Eceoğlu, Osman and Ünal, İlker
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AGRICULTURAL robots , *MOBILE robots , *AUTONOMOUS robots , *ORCHARDS , *GEOGRAPHIC information systems - Abstract
A typical orchard's mechanical operation consists of three or four stages: lining and digging for plantation, moving the seedling from nurseries to the farm, moving the seedling to the planting hole, and planting the seedling in the hole. However, the digging of the planting hole is the most time-consuming operation. In fruit orchards, the use of robots is increasingly becoming more prevalent to increase operational efficiency. They offer practical and effective services to both industry and people, whether they are assigned to plant trees, reduce the use of chemical fertilizers, or carry heavy loads to relieve staff. Robots can operate for extended periods of time and can be highly adept at repetitive tasks like planting many trees. The present study aims to identify the locations for planting trees in orchards using geographic information systems (GISs), to develop an autonomous drilling machine and use the developed robot to open planting holes. There is no comparable study on autonomous hole planting in the literature in this regard. The agricultural mobile robot is a four=wheeled nonholonomic robot with differential steering and forwarding capability to stable target positions. The designed mobile robot can be used in fully autonomous, partially autonomous, or fully manual modes. The drilling system, which is a y-axis shifter driven by a DC motor with a reducer includes an auger with a 2.1 HP gasoline engine. SOLIDWORKS 2020 software was used for designing and drawing the mobile robot and drilling system. The Microsoft Visual Basic.NET programming language was used to create the robot navigation system and drilling mechanism software. The cross-track error (XTE), which determines the distances between the actual and desired holes positions, was utilized to analyze the steering accuracy of the mobile robot to the drilling spots. Consequently, the average of the arithmetic means was determined to be 4.35 cm, and the standard deviation was 1.73 cm. This figure indicates that the suggested system is effective for drilling plant holes in orchards. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Multi-Robot Collaborative Mapping with Integrated Point-Line Features for Visual SLAM.
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Xia, Yu, Wu, Xiao, Ma, Tao, Zhu, Liucun, Cheng, Jingdi, and Zhu, Junwu
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VISUAL odometry , *MOBILE operating systems , *MOBILE robots , *ALGORITHMS , *PHOTOGRAMMETRY , *ROBOTS - Abstract
Simultaneous Localization and Mapping (SLAM) enables mobile robots to autonomously perform localization and mapping tasks in unknown environments. Despite significant progress achieved by visual SLAM systems in ideal conditions, relying solely on a single robot and point features for mapping in large-scale indoor environments with weak-texture structures can affect mapping efficiency and accuracy. Therefore, this paper proposes a multi-robot collaborative mapping method based on point-line fusion to address this issue. This method is designed for indoor environments with weak-texture structures for localization and mapping. The feature-extraction algorithm, which combines point and line features, supplements the existing environment point feature-extraction method by introducing a line feature-extraction step. This integration ensures the accuracy of visual odometry estimation in scenes with pronounced weak-texture structure features. For relatively large indoor scenes, a scene-recognition-based map-fusion method is proposed in this paper to enhance mapping efficiency. This method relies on visual bag of words to determine overlapping areas in the scene, while also proposing a keyframe-extraction method based on photogrammetry to improve the algorithm's robustness. By combining the Perspective-3-Point (P3P) algorithm and Bundle Adjustment (BA) algorithm, the relative pose-transformation relationships of multi-robots in overlapping scenes are resolved, and map fusion is performed based on these relative pose relationships. We evaluated our algorithm on public datasets and a mobile robot platform. The experimental results demonstrate that the proposed algorithm exhibits higher robustness and mapping accuracy. It shows significant effectiveness in handling mapping in scenarios with weak texture and structure, as well as in small-scale map fusion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Mapless Path Planning for Mobile Robot Based on Improved Deep Deterministic Policy Gradient Algorithm.
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Zhang, Shuzhen, Tang, Wei, Li, Panpan, and Zha, Fusheng
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ROBOTIC path planning , *MACHINE learning , *MOBILE robots , *ALGORITHMS - Abstract
In the traditional Deep Deterministic Policy Gradient (DDPG) algorithm, path planning for mobile robots in mapless environments still encounters challenges regarding learning efficiency and navigation performance, particularly adaptability and robustness to static and dynamic obstacles. To address these issues, in this study, an improved algorithm frame was proposed that designs the state and action spaces, and introduces a multi-step update strategy and a dual-noise mechanism to improve the reward function. These improvements significantly enhance the algorithm's learning efficiency and navigation performance, rendering it more adaptable and robust in complex mapless environments. Compared to the traditional DDPG algorithm, the improved algorithm shows a 20% increase in the stability of the navigation success rate with static obstacles along with a 25% reduction in pathfinding steps for smoother paths. In environments with dynamic obstacles, there is a remarkable 45% improvement in success rate. Real-world mobile robot tests further validated the feasibility and effectiveness of the algorithm in true mapless environments. [ABSTRACT FROM AUTHOR]
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- 2024
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11. W-VSLAM: A Visual Mapping Algorithm for Indoor Inspection Robots.
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Luo, Dingji, Huang, Yucan, Huang, Xuchao, Miao, Mingda, and Gao, Xueshan
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ROBOT motion , *STANDARD deviations , *JACOBIAN matrices , *DEGREES of freedom , *PLANAR motion , *MOBILE robots - Abstract
In recent years, with the widespread application of indoor inspection robots, high-precision, robust environmental perception has become essential for robotic mapping. Addressing the issues of visual–inertial estimation inaccuracies due to redundant pose degrees of freedom and accelerometer drift during the planar motion of mobile robots in indoor environments, we propose a visual SLAM perception method that integrates wheel odometry information. First, the robot's body pose is parameterized in SE(2) and the corresponding camera pose is parameterized in SE(3). On this basis, we derive the visual constraint residuals and their Jacobian matrices for reprojection observations using the camera projection model. We employ the concept of pre-integration to derive pose-constraint residuals and their Jacobian matrices and utilize marginalization theory to derive the relative pose residuals and their Jacobians for loop closure constraints. This approach solves the nonlinear optimization problem to obtain the optimal pose and landmark points of the ground-moving robot. A comparison with the ORBSLAM3 algorithm reveals that, in the recorded indoor environment datasets, the proposed algorithm demonstrates significantly higher perception accuracy, with root mean square error (RMSE) improvements of 89.2% in translation and 98.5% in rotation for absolute trajectory error (ATE). The overall trajectory localization accuracy ranges between 5 and 17 cm, validating the effectiveness of the proposed algorithm. These findings can be applied to preliminary mapping for the autonomous navigation of indoor mobile robots and serve as a basis for path planning based on the mapping results. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Advanced Sensing and Control Technologies for Autonomous Robots.
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Xie, Yuanlong, Wang, Shuting, Zheng, Shiqi, and Hu, Zhaozheng
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INDUSTRIAL robots , *ROBOTIC path planning , *AUTONOMOUS robots , *ROBOTICS , *OPTIMIZATION algorithms , *MOBILE robots , *MULTIAGENT systems - Published
- 2024
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13. UVIO: Adaptive Kalman Filtering UWB-Aided Visual-Inertial SLAM System for Complex Indoor Environments.
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Li, Junxi, Wang, Shouwen, Hao, Jiahui, Ma, Biao, and Chu, Henry K.
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GLOBAL Positioning System , *ADAPTIVE filters , *KALMAN filtering , *MEASUREMENT errors , *COVARIANCE matrices , *MOBILE robots - Abstract
Precise positioning in an indoor environment is a challenging task because it is difficult to receive a strong and reliable global positioning system (GPS) signal. For existing wireless indoor positioning methods, ultra-wideband (UWB) has become more popular because of its low energy consumption and high interference immunity. Nevertheless, factors such as indoor non-line-of-sight (NLOS) obstructions can still lead to large errors or fluctuations in the measurement data. In this paper, we propose a fusion method based on ultra-wideband (UWB), inertial measurement unit (IMU), and visual simultaneous localization and mapping (V-SLAM) to achieve high accuracy and robustness in tracking a mobile robot in a complex indoor environment. Specifically, we first focus on the identification and correction between line-of-sight (LOS) and non-line-of-sight (NLOS) UWB signals. The distance evaluated from UWB is first processed by an adaptive Kalman filter with IMU signals for pose estimation, where a new noise covariance matrix using the received signal strength indicator (RSSI) and estimation of precision (EOP) is proposed to reduce the effect due to NLOS. After that, the corrected UWB estimation is tightly integrated with IMU and visual SLAM through factor graph optimization (FGO) to further refine the pose estimation. The experimental results show that, compared with single or dual positioning systems, the proposed fusion method provides significant improvements in positioning accuracy in a complex indoor environment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. Adaptive Distributed Control for Leader–Follower Formation Based on a Recurrent SAC Algorithm.
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Li, Mingfei, Liu, Haibin, Xie, Feng, and Huang, He
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ADAPTIVE control systems ,PROBLEM solving ,ALGORITHMS ,GENERALIZATION ,ROBOTS ,REINFORCEMENT learning ,MOBILE robots - Abstract
This study proposes a novel adaptive distributed recurrent SAC (Soft Actor–Critic) control method to address the leader–follower formation control problem of omnidirectional mobile robots. Our method successfully eliminates the reliance on the complete state of the leader and achieves the task of formation solely using the pose between robots. Moreover, we develop a novel recurrent SAC reinforcement learning framework that ensures that the controller exhibits good transient and steady-state characteristics to achieve outstanding control performance. We also present an episode-based memory replay buffer and sampling approaches, along with a unique normalized reward function, which expedites the recurrent SAC reinforcement learning formation framework to converge rapidly and receive consistent incentives across various leader–follower tasks. This facilitates better learning and adaptation to the formation task requirements in different scenarios. Furthermore, to bolster the generalization capability of our method, we normalized the state space, effectively eliminating differences between formation tasks of different shapes. Different shapes of leader–follower formation experiments in the Gazebo simulator achieve excellent results, validating the efficacy of our method. Comparative experiments with traditional PID and common network controllers demonstrate that our method achieves faster convergence and greater robustness. These simulation results provide strong support for our study and demonstrate the potential and reliability of our method in solving real-world problems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. A Multidisciplinary Learning Model Using AGV and AMR for Industry 4.0/5.0 Laboratory Courses: A Study.
- Author
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Cservenák, Ákos and Husár, Jozef
- Subjects
INDUSTRIAL robots ,EDUCATIONAL planning ,MOBILE robots ,AUTONOMOUS robots ,STUDENT engagement - Abstract
This paper presents the development of a multidisciplinary learning model using automated guided vehicles (AGVs) and autonomous mobile robots (AMRs) for laboratory courses, focusing on Industry 4.0 and 5.0 paradigms. Industry 4.0 and 5.0 emphasize advanced industrial automation and human–robot collaboration, which requires innovative educational strategies. Motivated by the need to align educational practices with these industry trends, the goal of this research is to design and implement an effective educational model integrating AGV and AMR. The methodology section details the complex development process, including technology selection, curriculum design, and laboratory exercise design. Data collection and analysis were conducted to assess the effectiveness of the model. The design phase outlines the structure of the educational model, integrating AGV and AMR into the laboratory modules and enriching them with industry collaboration and practical case studies. The results of a pilot implementation are presented, showing the impact of the model on students' learning outcomes compared to traditional strategies. The evaluation reveals significant improvements in student engagement and understanding of industrial automation. The implications of these findings are discussed, challenges and potential improvements identified, and alignment with current educational trends discussed. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Reinforcement-Learning-Based Path Planning: A Reward Function Strategy.
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Jaramillo-Martínez, Ramón, Chavero-Navarrete, Ernesto, and Ibarra-Pérez, Teodoro
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ROBOTIC path planning ,REINFORCEMENT learning ,AUTONOMOUS robots ,MOBILE robots ,LYAPUNOV functions - Abstract
Path planning is a fundamental task for autonomous mobile robots (AMRs). Classic approaches provide an analytical solution by searching for the trajectory with the shortest distance; however, reinforcement learning (RL) techniques have been proven to be effective in solving these problems with the experiences gained by agents in real time. This study proposes a reward function that motivates an agent to select the shortest path with fewer turns. The solution to the RL technique is obtained via dynamic programming and Deep Q-Learning methods. In addition, a path-tracking control design is proposed based on the Lyapunov candidate function. The results indicate that RL algorithms show superior performance compared to classic A* algorithms. The number of turns is reduced by 50%, resulting in a decrease in the total distance ranging from 3.2% to 36%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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17. Deep Learning-Based Vision Systems for Robot Semantic Navigation: An Experimental Study.
- Author
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Alotaibi, Albandari, Alatawi, Hanan, Binnouh, Aseel, Duwayriat, Lamaa, Alhmiedat, Tareq, and Alia, Osama Moh'd
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OBJECT recognition (Computer vision) ,ROBOT vision ,MOBILE robots ,NAUTICAL charts ,ROBOTS ,DEEP learning - Abstract
Robot semantic navigation has received significant attention recently, as it aims to achieve reliable mapping and navigation accuracy. Object detection tasks are vital in this endeavor, as a mobile robot needs to detect and recognize the objects in the area of interest to build an effective semantic map. To achieve this goal, this paper classifies and discusses recently developed object detection approaches and then presents the available vision datasets that can be employed in robot semantic navigation applications. In addition, this paper discusses several experimental studies that have validated the efficiency of object detection algorithms, including Faster R-CNN, YOLO v5, and YOLO v8. These studies also utilized a vision dataset to design and develop efficient robot semantic navigation systems, which is also discussed. According to several experiments conducted in a Fablab area, the YOLO v8 object classification model achieved the best results in terms of classification accuracy and processing speed. [ABSTRACT FROM AUTHOR]
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- 2024
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18. Virtual Teleoperation System for Mobile Manipulator Robots Focused on Object Transport and Manipulation.
- Author
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Pantusin, Fernando J., Carvajal, Christian P., Ortiz, Jessica S., and Andaluz, Víctor H.
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ROBOT motion ,MOBILE robots ,DEGREES of freedom ,VIRTUAL reality ,OBJECT manipulation - Abstract
This work describes the development of a tool for the teleoperation of robots. The tool is developed in a virtual environment using the Unity graphics engine. For the development of the application, a kinematic model and a dynamic model of a mobile manipulator are used. The mobile manipulator robot consists of an omnidirectional platform and an anthropomorphic robotic arm with 4 degrees of freedom (4DOF). The model is essential to emulate the movements of the robot and to facilitate the immersion in the virtual environment. In addition, the control algorithms are established and developed in MATLAB 2020 software, which improves the acquisition of knowledge to teleoperate robots and execute tasks of manipulation and transport of objects. This methodology offers a cheaper and safer alternative to real physical systems, as it reduces both the costs and risks associated with using a real robot for training. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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19. An Overview of Model-Free Adaptive Control for the Wheeled Mobile Robot.
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Zhang, Chen, Cen, Chen, and Huang, Jiahui
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ADAPTIVE control systems ,COMPACTING ,INTELLIGENCE levels ,CLOSED loop systems ,INFORMATION resources management ,MOBILE robots - Abstract
Control technology for wheeled mobile robots is one of the core focuses in the current field of robotics research. Within this domain, model-free adaptive control (MFAC) methods, with their advanced data-driven strategies, have garnered widespread attention. The unique characteristic of these methods is their ability to operate without relying on prior model information of the control system, which showcases their exceptional capability in ensuring closed-loop system stability. This paper extensively details three dynamic linearization techniques of MFAC: compact form dynamic linearization, partial form dynamic linearization and full form dynamic linearization. These techniques lay a solid theoretical foundation for MFAC. Subsequently, the article delves into some advanced MFAC schemes, such as dynamic event-triggered MFAC and iterative learning MFAC. These schemes further enhance the efficiency and intelligence level of control systems. In the concluding section, the paper briefly discusses the future development potential and possible research directions of MFAC, aiming to offer references and insights for future innovations in control technology for wheeled mobile robots. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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20. Efficient Path Planning Algorithm Based on Laser SLAM and an Optimized Visibility Graph for Robots.
- Author
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Hu, Yunjie, Xie, Fei, Yang, Jiquan, Zhao, Jing, Mao, Qi, Zhao, Fei, and Liu, Xixiang
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MOBILE robots , *GRIDS (Cartography) , *POINT cloud , *SEARCH algorithms , *SCHEDULING , *POTENTIAL field method (Robotics) - Abstract
Mobile robots' efficient path planning has long been a challenging task due to the complexity and dynamism of environments. If an occupancy grid map is used in path planning, the number of grids is determined by grid resolution and the size of the actual environment. Excessively high resolution increases the number of traversed grid nodes and thus prolongs path planning time. To address this challenge, this paper proposes an efficient path planning algorithm based on laser SLAM and an optimized visibility graph for mobile robots, which achieves faster computation of the shortest path using the optimized visibility graph. Firstly, the laser SLAM algorithm is used to acquire the undistorted LiDAR point cloud data, which are converted into a visibility graph. Secondly, a bidirectional A* path search algorithm is combined with the Minimal Construct algorithm, enabling the robot to only compute heuristic paths to the target node during path planning in order to reduce search time. Thirdly, a filtering method based on edge length and the number of vertices of obstacles is proposed to reduce redundant vertices and edges in the visibility graph. Additionally, the bidirectional A* search method is implemented for pathfinding in the efficient path planning algorithm proposed in this paper to reduce unnecessary space searches. Finally, simulation and field tests are conducted to validate the algorithm and compare its performance with classic algorithms. The test results indicate that the method proposed in this paper exhibits superior performance in terms of path search time, navigation time, and distance compared to D* Lite, FAR, and FPS algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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21. A Dynamic Event-Based Recursive State Estimation for Mobile Robot Localization.
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Zhu, Li, Gao, Ruifeng, Huang, Cong, Shi, Quan, and Shi, Zhenquan
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MATHEMATICAL induction ,MOBILE robots ,SENSES - Abstract
This paper deals with the recursive state estimation issue for mobile robot localization under a dynamic event-based mechanism. To enhance the utilization of communication resources, a dynamic event-based transmission protocol is utilized to reduce unnecessary measurement transmissions by introducing an auxiliary dynamical variable to adjust threshold parameters. The primary objective of this paper is to develop a dynamic event-based recursive state estimation scheme for the mobile robot localization problem in the presence of the impact of the dynamic event-based mechanism such that an upper bound on the estimation error covariance is firstly guaranteed by using mathematical induction and then is locally minimized by virtue of appropriately choosing the gain parameters. Furthermore, the boundedness analysis of the estimation error is conducted by establishing an evaluation criteria in the mean-squared sense. Finally, an experimental example is conducted to verify the feasibility of the proposed mobile robot localization strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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22. Embedding a Real-Time Strawberry Detection Model into a Pesticide-Spraying Mobile Robot for Greenhouse Operation.
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El Amraoui, Khalid, El Ansari, Mohamed, Lghoul, Mouataz, El Alaoui, Mustapha, Abanay, Abdelkrim, Jabri, Bouazza, Masmoudi, Lhoussaine, and Valente de Oliveira, José
- Subjects
AGRICULTURE ,MOBILE robots ,STRAWBERRIES ,GREENHOUSES ,FRUIT - Abstract
The real-time detection of fruits and plants is a crucial aspect of digital agriculture, enhancing farming efficiency and productivity. This study addresses the challenge of embedding a real-time strawberry detection system in a small mobile robot operating within a greenhouse environment. The embedded system is based on the YOLO architecture running in a single GPU card, with the Open Neural Network Exchange (ONNX) representation being employed to accelerate the detection process. The experiments conducted in this study demonstrate that the proposed model achieves a mean average precision (mAP) of over 97%, processing eight frames per second for 512 × 512 pixel images. These results affirm the utility of the proposed approach in detecting strawberry plants in order to optimize the spraying process and avoid inflicting any harm on the plants. The goal of this research is to highlight the potential of integrating advanced detection algorithms into small-scale robotics, providing a viable solution for enhancing precision agriculture practices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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23. An Adaptive Control Based on Improved Gray Wolf Algorithm for Mobile Robots.
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Xue, Haoran, Lu, Shouyin, and Zhang, Chengbin
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GREY Wolf Optimizer algorithm ,ROBOT motion ,ADAPTIVE control systems ,INTELLIGENT control systems ,ROBOT control systems ,MOBILE robots - Abstract
In this paper, a novel intelligent controller for the trajectory tracking control of a nonholonomic mobile robot with time-varying parameter uncertainty and external disturbances in the case of tire hysteresis loss is proposed. Based on tire dynamics principles, a dynamic and kinematic model of a nonholonomic mobile robot is established, and the neural network approximation model of the system's nonlinear term caused by many coupling factors when the robot enters a roll is given. Then, in order to adaptively estimate the unknown upper bounds on the uncertainties and perturbations for each subsystem in real time, a novel adaptive law employed online as a gain parameter is designed to solve the problem of inter-system coupling and reduce the transient response time of the system with lower uncertainties. Additionally, based on improved gray wolf optimizer and fuzzy system techniques, an adaptive algorithm using the gray wolf optimizer study space as the output variable of the fuzzy system to expand the search area of the gray wolves is developed to optimize the controller parameters online. Finally, the efficacy of the proposed intelligent control scheme and the feasibility of the proposed algorithm are verified by the 2023a version of MATLAB/Simulink platform. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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24. Policy Compression for Intelligent Continuous Control on Low-Power Edge Devices.
- Author
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Avé, Thomas, De Schepper, Tom, and Mets, Kevin
- Subjects
- *
DEEP reinforcement learning , *REINFORCEMENT learning , *AUTONOMOUS robots , *INTELLIGENT control systems , *MOBILE robots - Abstract
Interest in deploying deep reinforcement learning (DRL) models on low-power edge devices, such as Autonomous Mobile Robots (AMRs) and Internet of Things (IoT) devices, has seen a significant rise due to the potential of performing real-time inference by eliminating the latency and reliability issues incurred from wireless communication and the privacy benefits of processing data locally. Deploying such energy-intensive models on power-constrained devices is not always feasible, however, which has led to the development of model compression techniques that can reduce the size and computational complexity of DRL policies. Policy distillation, the most popular of these methods, can be used to first lower the number of network parameters by transferring the behavior of a large teacher network to a smaller student model before deploying these students at the edge. This works well with deterministic policies that operate using discrete actions. However, many real-world tasks that are power constrained, such as in the field of robotics, are formulated using continuous action spaces, which are not supported. In this work, we improve the policy distillation method to support the compression of DRL models designed to solve these continuous control tasks, with an emphasis on maintaining the stochastic nature of continuous DRL algorithms. Experiments show that our methods can be used effectively to compress such policies up to 750% while maintaining or even exceeding their teacher's performance by up to 41% in solving two popular continuous control tasks. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Social Type-Aware Navigation Framework for Mobile Robots in Human-Shared Environments.
- Author
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Kang, Sumin, Yang, Sungwoo, Kwak, Daewon, Jargalbaatar, Yura, and Kim, Donghan
- Subjects
- *
PERSONAL space , *AUTONOMOUS robots , *SOCIAL space , *SOCIAL interaction , *GAUSSIAN function , *SOCIAL robots , *MOBILE robots - Abstract
As robots become increasingly common in human-populated environments, they must be perceived as social beings and behave socially. People try to preserve their own space during social interactions with others, and this space depends on a variety of factors, such as individual characteristics or their age. In real-world social spaces, there are many different types of people, and robots need to be more sensitive, especially when interacting with vulnerable subjects such as children. However, the current navigation methods do not consider these differences and apply the same avoidance strategies to everyone. Thus, we propose a new navigation framework that considers different social types and defines appropriate personal spaces for each, allowing robots to respect them. To this end, the robot needs to classify people in a real environment into social types and define the personal space for each type as a Gaussian asymmetric function to respect them. The proposed framework is validated through simulations and real-world experiments, demonstrating that the robot can improve the quality of interactions with people by providing each individual with an adaptive personal space. The proposed costmap layer is available on GitHub. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Integration of Tracking, Re-Identification, and Gesture Recognition for Facilitating Human–Robot Interaction.
- Author
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Lee, Sukhan, Lee, Soojin, and Park, Hyunwoo
- Subjects
- *
AUTONOMOUS robots , *TRANSPORTATION of patients , *NURSES as patients , *EDGE computing , *PATIENT monitoring , *MOBILE robots - Abstract
For successful human–robot collaboration, it is crucial to establish and sustain quality interaction between humans and robots, making it essential to facilitate human–robot interaction (HRI) effectively. The evolution of robot intelligence now enables robots to take a proactive role in initiating and sustaining HRI, thereby allowing humans to concentrate more on their primary tasks. In this paper, we introduce a system known as the Robot-Facilitated Interaction System (RFIS), where mobile robots are employed to perform identification, tracking, re-identification, and gesture recognition in an integrated framework to ensure anytime readiness for HRI. We implemented the RFIS on an autonomous mobile robot used for transporting a patient, to demonstrate proactive, real-time, and user-friendly interaction with a caretaker involved in monitoring and nursing the patient. In the implementation, we focused on the efficient and robust integration of various interaction facilitation modules within a real-time HRI system that operates in an edge computing environment. Experimental results show that the RFIS, as a comprehensive system integrating caretaker recognition, tracking, re-identification, and gesture recognition, can provide an overall high quality of interaction in HRI facilitation with average accuracies exceeding 90% during real-time operations at 5 FPS. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
27. Safe Coverage Control of Multi-Agent Systems and Its Verification in ROS/Gazebo Environment.
- Author
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Siri, Fidelia Chaitra, Song, Jie, and Svinin, Mikhail
- Subjects
- *
CENTROIDAL Voronoi tessellations , *MULTIAGENT systems , *MOBILE robots , *ALGORITHMS , *ROBOTS - Abstract
This paper presents safe coverage control algorithms for multi-agent systems, integrating Centroidal Voronoi Tessellation (CVT) and control barrier functions (CBFs). This study aims to ensure safety and spatial optimization by combining CVT and CBFs for obstacle avoidance, testing the controller through simulations, and verifying the results with RT mobile robots. This development of safe coverage control algorithms for multi-agent systems achieves a synergy that addresses both safety and spatial optimization, which are crucial for multi-agent systems. The proposed CVT-CBF-based controller has been validated through extensive simulations in the ROS/Gazebo environment and physical experiments with RT robots, demonstrating its effectiveness in achieving collision-free coverage. This study provides a comprehensive understanding of the integration of CVT and CBFs for safe coverage control with obstacle avoidance in multi-agent systems, highlighting both its potential and the necessary considerations for practical deployment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
28. An ANFIS-Based Strategy for Autonomous Robot Collision-Free Navigation in Dynamic Environments.
- Author
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Stavrinidis, Stavros and Zacharia, Paraskevi
- Subjects
AUTONOMOUS robots ,ROBOTICS ,ROBOTS ,ULTRASONICS ,MOBILE robots ,NAVIGATION - Abstract
Autonomous navigation in dynamic environments is a significant challenge in robotics. The primary goals are to ensure smooth and safe movement. This study introduces a control strategy based on an Adaptive Neuro-Fuzzy Inference System (ANFIS). It enhances autonomous robot navigation in dynamic environments with a focus on collision-free path planning. The strategy uses a path-planning technique to develop a trajectory that allows the robot to navigate smoothly while avoiding both static and dynamic obstacles. The developed control system incorporates four ANFIS controllers: two are tasked with guiding the robot toward its end point, and the other two are activated for obstacle avoidance. The experimental setup conducted in CoppeliaSim involves a mobile robot equipped with ultrasonic sensors navigating in an environment with static and dynamic obstacles. Simulation experiments are conducted to demonstrate the model's capability in ensuring collision-free navigation, employing a path-planning algorithm to ascertain the shortest route to the target destination. The simulation results highlight the superiority of the ANFIS-based approach over conventional methods, particularly in terms of computational efficiency and navigational smoothness. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Improved Feature Point Extraction Method of VSLAM in Low-Light Dynamic Environment.
- Author
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Wang, Yang, Zhang, Yi, Hu, Lihe, Ge, Gengyu, Wang, Wei, and Tan, Shuyi
- Subjects
FEATURE extraction ,TEST methods ,HISTOGRAMS ,MOBILE robots - Abstract
Visual simultaneous localization and mapping (VSLAM) is pivotal for intelligent mobile robots. VSLAM systems can be used to identify scenes by obtaining massive amounts of redundant texture information from the environment. However, VSLAM faces a major challenge in dynamic low-light environments, in which the extraction of feature points is often difficult, leading to tracking failure with mobile robots. Therefore, we developed a method to improve the feature point extraction method used for VSLAM. We first used the contrast limited adaptive histogram equalization (CLAHE) method to increase the contrast in low-light images, allowing for the extraction of more feature points. Second, in order to increase the effectiveness of the extracted feature points, the redundant feature points were removed. We developed three conditions to filter the feature points. Finally, the proposed method was tested on popular datasets (e.g., TUM and OpenLORIS-Scene), and the results were compared with those of several traditional methods. The results of the experiments showed that the proposed method is feasible and highly robust in dynamic low-light environments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Implementation of a Small-Sized Mobile Robot with Road Detection, Sign Recognition, and Obstacle Avoidance.
- Author
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Wong, Ching-Chang, Weng, Kun-Duo, Yu, Bo-Yun, and Chou, Yung-Shan
- Subjects
OPTICAL radar ,LIDAR ,MOBILE robots ,PROCESS capability ,DATA augmentation - Abstract
In this study, under the limited volume of 18 cm × 18 cm × 21 cm, a small-sized mobile robot is designed and implemented. It consists of a CPU, a GPU, a 2D LiDAR (Light Detection And Ranging), and two fisheye cameras to let the robot have good computing processing and graphics processing capabilities. In addition, three functions of road detection, sign recognition, and obstacle avoidance are implemented on this small-sized robot. For road detection, we divide the captured image into four areas and use Intel NUC to perform road detection calculations. The proposed method can significantly reduce the system load and also has a high processing speed of 25 frames per second (fps). For sign recognition, we use the YOLOv4-tiny model and a data augmentation strategy to significantly improve the computing performance of this model. From the experimental results, it can be seen that the mean Average Precision (mAP) of the used model has increased by 52.14%. For obstacle avoidance, a 2D LiDAR-based method with a distance-based filtering mechanism is proposed. The distance-based filtering mechanism is proposed to filter important data points and assign appropriate weights, which can effectively reduce the computational complexity and improve the robot's response speed to avoid obstacles. Some results and actual experiments illustrate that the proposed methods for these three functions can be effectively completed in the implemented small-sized robot. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Structural Design and Analysis of Multi-Directional Foot Mobile Robot.
- Author
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Yang, Hui, Shi, Wen, Long, Zhongjie, and Jiang, Zhouxiang
- Subjects
MOBILE robots ,DEGREES of freedom ,THEORY of screws ,ROBOT motion ,STRUCTURAL optimization ,FOOT - Abstract
Traditional mobile robots have limited mobility in complex terrain environments. Generally, the closed-chain leg structure of a foot-type robot relies on the speed difference to turn, but it is difficult to complete the turning action in narrow spaces. Therefore, this study proposes a closed-chain foot-type robot that can move in multiple directions, inspired by the WATT-I leg structure. Firstly, the closed-chain single-leg structure is designed, and the leg structure is analyzed in terms of the degrees of freedom, kinematics, and singularity. A simulation is also carried out. Secondly, based on the present trajectory, a heuristic algorithm is used to solve the inverse trajectory problem, and the size of the mechanism is optimized. Finally, the steering mechanism of the leg with a zero turning radius is designed and analyzed, which achieves the steering function of the whole robot and satisfies the goal of enabling the foot robot to walk in all directions. This study provides theoretical guidance for the structural dimension optimization of the proposed foot mobile robot and its application in engineering fields such as rescue, exploration, and the military. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Comparison between an Adaptive Gain Scheduling Control Strategy and a Fuzzy Multimodel Intelligent Control Applied to the Speed Control of Non-Holonomic Robots.
- Author
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Miquelanti, Mateus G., Pugliese, Luiz F., Silva, Waner W. A. G., Braga, Rodrigo A. S., and Monte-Mor, Juliano A.
- Subjects
ADAPTIVE fuzzy control ,NONHOLONOMIC constraints ,INTELLIGENT control systems ,ADAPTIVE control systems ,DATA acquisition systems ,MOBILE robots - Abstract
The main objective of this work is to address problems related to the speed control of mobile robots with non-holonomic constraints and differential traction—specifically, robots for football games in the VSS (Very Small Size) category. To achieve this objective, an implementation and comparison is carried out between two control strategies: an adaptive control strategy by gain scheduling and a fuzzy multimodel intelligent control strategy. The mathematical models of the wheel motors for each operating range are approximated by a first-order system since data acquisition is performed using the step response. Tuning of the proportional and integral gains of the local controllers is carried out using the root locus technique in discrete time. For each mathematical model obtained for an operating range, a local controller is tuned. Finally, with the local controllers in hand, the implementation of and comparison between the gain scheduling adaptive control strategy and the fuzzy multimodel intelligent control strategy are carried out, in which the control strategies are programmed into the low-level code of a non-holonomic robot with a differential drive to verify the performance of the speed tracking dynamics imposed on the wheel motors to improve robot navigation during a robot football match. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Challenges in the Guidance, Navigation and Control of Autonomous and Transport Vehicles.
- Author
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Horri, Nadjim, Holderbaum, William, and Giulietti, Fabrizio
- Subjects
MACHINE learning ,ANT algorithms ,GLOBAL Positioning System ,DRIVER assistance systems ,TRAJECTORY optimization ,MOBILE robots ,TRAFFIC circles ,DRONE aircraft - Abstract
This document provides a summary of a book that explores the challenges and advancements in the guidance, navigation, and control (GNC) of autonomous and transport vehicles. It emphasizes the need for vehicles to operate autonomously and efficiently in congested city environments and discusses the development of collaborative GNC for capabilities like platooning. The document also mentions the impact of policies on GNC, such as the authorization of eVTOL and drone operations by the FAA in the United States. It highlights the growing research areas in vehicle navigation and control, including sensor fusion, trajectory optimization, and control challenges. The document concludes by encouraging readers to explore the publications in the Special Issue to gain a deeper understanding of the emerging research priorities in GNC for a diverse range of vehicles. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
34. Experimental Study on the Longitudinal Motion Performance of a Spherical Robot Rolling on Sandy Terrain.
- Author
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Li, Minggang, Sun, Hanxu, Ma, Long, Huo, Dongshuai, Gao, Panpan, and Wang, Zhantong
- Subjects
ANGULAR acceleration ,ROLLING friction ,MOBILE robots ,ANGULAR velocity ,ROBOT control systems - Abstract
To provide the necessary theoretical models of sphere–soil interaction for the structural design, motion control, and simulation of spherical robots, this paper derives analytical expressions for traction force and driving torque when spherical robots slide and sink into sandy terrain, based on terramechanics and multibody dynamics. Furthermore, orthogonal experimental analysis identifies the load, joint angular acceleration, and maximum joint angular velocity of spherical robots as influencing factors, highlighting that the load significantly affects their longitudinal motion performance. Experimental results indicate that rolling friction and additional resistance on sandy terrain cannot be ignored. The corrected theoretical model effectively replicates the temporal variation of driving torque exerted by spherical robots on sandy terrain. Numerical computations and experimental analyses demonstrate that increasing the radius of the sphere shell, the load, and the slip ratio all lead to increased traction force and driving torque. However, traction force and driving torque begin to decrease once the slip ratio reaches approximately 0.5. Therefore, in the design of spherical robot structures and control laws, appropriate parameters such as load and slip ratio should be chosen based on the established sphere–soil interaction theoretical model to achieve high-quality longitudinal motion performance on sandy terrain. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Optimal Control-Based Algorithm Design and Application for Trajectory Tracking of a Mobile Robot with Four Independently Steered and Four Independently Actuated Wheels.
- Author
-
Ćaran, Branimir, Milić, Vladimir, Švaco, Marko, and Jerbić, Bojan
- Subjects
LINEAR velocity ,ROBOT control systems ,RICCATI equation ,TIME-varying systems ,DIFFERENTIAL equations ,MOBILE robots - Abstract
This paper deals with the synthesis and implementation of a controller for asymptotic tracking of the desired trajectory of a mobile robot. The mobile robot used for the experimental validation has eight motors with an inner control loop. Four steering actuators are controlled using position controllers and four driving actuators are controlled using velocity controllers. A complex robot kinematic model is converted into a control-oriented linear time-varying system, which is then used to design a time-varying control law that minimizes the quadratic optimality criterion. In contrast to conventional methodologies for solving the corresponding Riccati differential equations, a computational approach that explicitly determines the time-varying controller matrix by employing recurrent matrix computations is proposed. Mobile robot control inputs (linear velocity, steering angles and steering velocities) are forwarded to the steering and driving actuators with properly tuned position and velocity controllers using an inverse kinematic model of the mobile robot. The obtained control law is evaluated on an experimental set-up of a real mobile robot system. The controller is implemented using the Robot Operating System. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Improvement and Fusion of D*Lite Algorithm and Dynamic Window Approach for Path Planning in Complex Environments.
- Author
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Gao, Yang, Han, Qidong, Feng, Shuo, Wang, Zhen, Meng, Teng, and Yang, Jingshuai
- Subjects
MOBILE robots ,AUTONOMOUS robots ,COST functions ,SCHEDULING ,ALGORITHMS ,POTENTIAL field method (Robotics) - Abstract
Effective path planning is crucial for autonomous mobile robots navigating complex environments. The "global–local" coupled path planning algorithm exhibits superior global planning capabilities and local adaptability. However, these algorithms often fail to fully realize their potential due to low efficiency and excessive constraints. To address these issues, this study introduces a simpler and more effective integration strategy. Specifically, this paper proposes using a bi-layer map and a feasible domain strategy to organically combine the D*Lite algorithm with the Dynamic Window Approach (DWA). The bi-layer map effectively reduces the number of nodes in global planning, enhancing the efficiency of the D*Lite algorithm. The feasible domain strategy decreases constraints, allowing the local algorithm DWA to utilize its local planning capabilities fully. Moreover, the cost functions of both the D*Lite algorithm and DWA have been refined, enabling the fused algorithm to cope with more complex environments. This paper conducts simulation experiments across various settings and compares our method with A_DWA, another "global–local" coupled approach, which combines A* and DWA. D_DWA significantly outperforms A_DWA in complex environments, despite a 7.43% increase in path length. It reduces the traversal of risk areas by 71.95%, accumulative risk by 80.34%, global planning time by 26.98%, and time cost by 35.61%. Additionally, D_DWA outperforms the A_Q algorithm, a coupled approach validated in real-world environments, which combines A* and Q-learning, achieving reductions of 1.34% in path length, 67.14% in traversal risk area, 78.70% in cumulative risk, 34.85% in global planning time, and 37.63% in total time cost. The results demonstrate the superiority of our proposed algorithm in complex scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Road Anomaly Detection with Unknown Scenes Using DifferNet-Based Automatic Labeling Segmentation.
- Author
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Nguyen, Phuc Thanh-Thien, Nguyen, Toan-Khoa, Nguyen, Dai-Dong, Su, Shun-Feng, and Kuo, Chung-Hsien
- Subjects
AUTONOMOUS robots ,PRIOR learning ,DEEP learning ,MOBILE robots ,NAVIGATION - Abstract
Obstacle avoidance is essential for the effective operation of autonomous mobile robots, enabling them to detect and navigate around obstacles in their environment. While deep learning provides significant benefits for autonomous navigation, it typically requires large, accurately labeled datasets, making the data's preparation and processing time-consuming and labor-intensive. To address this challenge, this study introduces a transfer learning (TL)-based automatic labeling segmentation (ALS) framework. This framework utilizes a pretrained attention-based network, DifferNet, to efficiently perform semantic segmentation tasks on new, unlabeled datasets. DifferNet leverages prior knowledge from the Cityscapes dataset to identify high-entropy areas as road obstacles by analyzing differences between the input and resynthesized images. The resulting road anomaly map was refined using depth information to produce a robust drivable area and map of road anomalies. Several off-the-shelf RGB-D semantic segmentation neural networks were trained using pseudo-labels generated by the ALS framework, with validation conducted on the GMRPD dataset. Experimental results demonstrated that the proposed ALS framework achieved mean precision, mean recall, and mean intersection over union (IoU) rates of 80.31%, 84.42%, and 71.99%, respectively. The ALS framework, through the use of transfer learning and the DifferNet network, offers an efficient solution for semantic segmentation of new, unlabeled datasets, underscoring its potential for improving obstacle avoidance in autonomous mobile robots. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Mars Exploration: Research on Goal-Driven Hierarchical DQN Autonomous Scene Exploration Algorithm.
- Author
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Zhou, Zhiguo, Chen, Ying, Yu, Jiabao, Zu, Bowen, Wang, Qian, Zhou, Xuehua, and Duan, Junwei
- Subjects
MACHINE learning ,MARTIAN exploration ,REINFORCEMENT learning ,DEEP learning ,PROBLEM solving ,MOBILE robots ,MOBILE learning - Abstract
In the non-deterministic, large-scale navigation environment under the Mars exploration mission, there is a large space for action and many environmental states. Traditional reinforcement learning algorithms that can only obtain rewards at target points and obstacles will encounter the problems of reward sparsity and dimension explosion, making the training speed too slow or even impossible. This work proposes a deep layered learning algorithm based on the goal-driven layered deep Q-network (GDH-DQN), which is more suitable for mobile robots to explore, navigate, and avoid obstacles without a map. The algorithm model is designed in two layers. The lower layer provides behavioral strategies to achieve short-term goals, and the upper layer provides selection strategies for multiple short-term goals. Use known position nodes as short-term goals to guide the mobile robot forward and achieve long-term obstacle avoidance goals. Hierarchical execution not only simplifies tasks but also effectively solves the problems of reward sparsity and dimensionality explosion. In addition, each layer of the algorithm integrates a Hindsight Experience Replay mechanism to improve performance, make full use of the goal-driven function of the node, and effectively avoid the possibility of misleading the agent by complex processes and reward function design blind spots. The agent adjusts the number of model layers according to the number of short-term goals, further improving the efficiency and adaptability of the algorithm. Experimental results show that, compared with the hierarchical DQN method, the navigation success rate of the GDH-DQN algorithm is significantly improved, and it is more suitable for unknown scenarios such as Mars exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. An Integrated Route and Path Planning Strategy for Skid–Steer Mobile Robots in Assisted Harvesting Tasks with Terrain Traversability Constraints.
- Author
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Urvina, Ricardo Paul, Guevara, César Leonardo, Vásconez, Juan Pablo, and Prado, Alvaro Javier
- Subjects
TRAVELING salesman problem ,MOBILE robots ,ORCHARDS ,CROP yields ,AGRICULTURAL equipment - Abstract
This article presents a combined route and path planning strategy to guide Skid–Steer Mobile Robots (SSMRs) in scheduled harvest tasks within expansive crop rows with complex terrain conditions. The proposed strategy integrates: (i) a global planning algorithm based on the Traveling Salesman Problem under the Capacitated Vehicle Routing approach and Optimization Routing (OR-tools from Google) to prioritize harvesting positions by minimum path length, unexplored harvest points, and vehicle payload capacity; and (ii) a local planning strategy using Informed Rapidly-exploring Random Tree ( IRRT * ) to coordinate scheduled harvesting points while avoiding low-traction terrain obstacles. The global approach generates an ordered queue of harvesting locations, maximizing the crop yield in a workspace map. In the second stage, the IRRT * planner avoids potential obstacles, including farm layout and slippery terrain. The path planning scheme incorporates a traversability model and a motion model of SSMRs to meet kinematic constraints. Experimental results in a generic fruit orchard demonstrate the effectiveness of the proposed strategy. In particular, the IRRT * algorithm outperformed RRT and RRT * with 96.1% and 97.6% smoother paths, respectively. The IRRT * also showed improved navigation efficiency, avoiding obstacles and slippage zones, making it suitable for precision agriculture. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Open-Vocabulary Predictive World Models from Sensor Observations.
- Author
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Karlsson, Robin, Asfandiyarov, Ruslan, Carballo, Alexander, Fujii, Keisuke, Ohtani, Kento, and Takeda, Kazuya
- Subjects
- *
PREDICTION models , *ROAD markings , *MOBILE robots , *INTELLIGENT agents , *DETECTORS - Abstract
Cognitive scientists believe that adaptable intelligent agents like humans perform spatial reasoning tasks by learned causal mental simulation. The problem of learning these simulations is called predictive world modeling. We present the first framework for a learning open-vocabulary predictive world model (OV-PWM) from sensor observations. The model is implemented through a hierarchical variational autoencoder (HVAE) capable of predicting diverse and accurate fully observed environments from accumulated partial observations. We show that the OV-PWM can model high-dimensional embedding maps of latent compositional embeddings representing sets of overlapping semantics inferable by sufficient similarity inference. The OV-PWM simplifies the prior two-stage closed-set PWM approach to the single-stage end-to-end learning method. CARLA simulator experiments show that the OV-PWM can learn compact latent representations and generate diverse and accurate worlds with fine details like road markings, achieving 69 mIoU over six query semantics on an urban evaluation sequence. We propose the OV-PWM as a versatile continual learning paradigm for providing spatio-semantic memory and learned internal simulation capabilities to future general-purpose mobile robots. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Trajectory Tracking with Obstacle Avoidance for Nonholonomic Mobile Robots with Diamond-Shaped Velocity Constraints and Output Performance Specifications.
- Author
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Trakas, Panagiotis S., Anogiatis, Spyridon I., and Bechlioulis, Charalampos P.
- Subjects
- *
MOBILE robots , *VELOCITY , *ADAPTIVE control systems - Abstract
In this paper, we address the trajectory-/target-tracking and obstacle-avoidance problem for nonholonomic mobile robots subjected to diamond-shaped velocity constraints and predefined output performance specifications. The proposed scheme leverages the adaptive performance control to dynamically adjust the user-defined output performance specifications, ensuring compliance with input and safety constraints. A key feature of this approach is the integration of multiple constraints into a single adaptive performance function, governed by a simple adaptive law. Additionally, we introduce a robust velocity estimator with a priori-determined performance attributes to reconstruct the unmeasured trajectory/target velocity. Finally, we validate the effectiveness and robustness of the proposed control scheme, through extensive simulations and a real-world experiment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Opportunistic Sensor-Based Authentication Factors in and for the Internet of Things.
- Author
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Saideh, Marc, Jamont, Jean-Paul, and Vercouter, Laurent
- Subjects
- *
INTERNET of things , *MULTI-factor authentication , *MOBILE robots - Abstract
Communication between connected objects in the Internet of Things (IoT) often requires secure and reliable authentication mechanisms to verify identities of entities and prevent unauthorized access to sensitive data and resources. Unlike other domains, IoT offers several advantages and opportunities, such as the ability to collect real-time data through numerous sensors. These data contains valuable information about the environment and other objects that, if used, can significantly enhance authentication processes. In this paper, we propose a novel idea to building opportunistic sensor-based authentication factors by leveraging existing IoT sensors in a system of systems approach. The objective is to highlight the promising prospects of opportunistic authentication factors in enhancing IoT security. We claim that sensors can be utilized to create additional authentication factors, thereby reinforcing existing object-to-object authentication mechanisms. By integrating these opportunistic sensor-based authentication factors into multi-factor authentication schemes, IoT security can be substantially improved. We demonstrate the feasibility and effectivenness of our idea through illustrative experiments in a parking entry scenario, involving both mobile robots and cars, achieving high identification accuracy. We highlight the potential of this novel method to improve IoT security and suggest future research directions for formalizing and comparing our approach with existing techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. An Adaptive Cooperative Localization Method for Heterogeneous Air-to-Ground Robots Based on Relative Distance Constraints in a Satellite-Denial Environment.
- Author
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Han, Shidong, Xiong, Zhi, and Shi, Chenfa
- Subjects
- *
INERTIAL navigation systems , *ROBOTS , *MOBILE robots - Abstract
Cooperative localization (CL) for air-to-ground robots in a satellite-denial environment has become a current research hotspot. The traditional distance-based heterogeneous multiple-robot CL method requires at least four unmanned aerial vehicles (UAVs) with known positions. When the number of known-position UAVs in a cluster collaborative network is insufficient, the traditional distance-based CL method has a certain inapplicability. A novel adaptive CL method for air-to-ground robots based on relative distance constraints is proposed in this paper. Based on a dynamically changing number of known-position UAVs in the cluster collaborative network, the adaptive fusion estimation threshold is set. When the number of known-position UAVs in the cluster cooperative network is large, the real-time dynamic topology characteristics of multiple robots' spatial geometric configurations are considered. The optimal spatial geometric configuration between UAVs and unmanned ground vehicles (UGVs) is utilized to achieve a high-precision CL solution for UGVs. Otherwise, in the event that the number of known-position UAVs in a cluster collaborative network is insufficient, distance observation constraint information between UAVs and UGVs is retained in real time. Position observation equations for UGVs' inertial navigation system (INS) have been constructed using inertial-based high-precision relative position constraints and relative distance constraints from historical to current times. The experimental results show that the proposed method achieves adaptive fusion estimation with a dynamically changing number of known-position UAVs in the cluster collaborative network, effectively verifying the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. YPL-SLAM: A Simultaneous Localization and Mapping Algorithm for Point–line Fusion in Dynamic Environments.
- Author
-
Du, Xinwu, Zhang, Chenglin, Gao, Kaihang, Liu, Jin, Yu, Xiufang, and Wang, Shusong
- Subjects
- *
LOCALIZATION (Mathematics) , *MOBILE robots , *TRACKING algorithms , *ALGORITHMS - Abstract
Simultaneous Localization and Mapping (SLAM) is one of the key technologies with which to address the autonomous navigation of mobile robots, utilizing environmental features to determine a robot's position and create a map of its surroundings. Currently, visual SLAM algorithms typically yield precise and dependable outcomes in static environments, and many algorithms opt to filter out the feature points in dynamic regions. However, when there is an increase in the number of dynamic objects within the camera's view, this approach might result in decreased accuracy or tracking failures. Therefore, this study proposes a solution called YPL-SLAM based on ORB-SLAM2. The solution adds a target recognition and region segmentation module to determine the dynamic region, potential dynamic region, and static region; determines the state of the potential dynamic region using the RANSAC method with polar geometric constraints; and removes the dynamic feature points. It then extracts the line features of the non-dynamic region and finally performs the point–line fusion optimization process using a weighted fusion strategy, considering the image dynamic score and the number of successful feature point–line matches, thus ensuring the system's robustness and accuracy. A large number of experiments have been conducted using the publicly available TUM dataset to compare YPL-SLAM with globally leading SLAM algorithms. The results demonstrate that the new algorithm surpasses ORB-SLAM2 in terms of accuracy (with a maximum improvement of 96.1%) while also exhibiting a significantly enhanced operating speed compared to Dyna-SLAM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Enhancing Visual Odometry with Estimated Scene Depth: Leveraging RGB-D Data with Deep Learning.
- Author
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Kostusiak, Aleksander and Skrzypczyński, Piotr
- Subjects
VISUAL odometry ,PARTICLE swarm optimization ,KINECT (Motion sensor) ,INPAINTING ,CAMERAS ,MOBILE robots - Abstract
Advances in visual odometry (VO) systems have benefited from the widespread use of affordable RGB-D cameras, improving indoor localization and mapping accuracy. However, older sensors like the Kinect v1 face challenges due to depth inaccuracies and incomplete data. This study compares indoor VO systems that use RGB-D images, exploring methods to enhance depth information. We examine conventional image inpainting techniques and a deep learning approach, utilizing newer depth data from devices like the Kinect v2. Our research highlights the importance of refining data from lower-quality sensors, which is crucial for cost-effective VO applications. By integrating deep learning models with richer context from RGB images and more comprehensive depth references, we demonstrate improved trajectory estimation compared to standard methods. This work advances budget-friendly RGB-D VO systems for indoor mobile robots, emphasizing deep learning's role in leveraging connections between image appearance and depth data. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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46. Energy Utilization Prediction Techniques for Heterogeneous Mobile Robots: A Review.
- Author
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Góra, Krystian, Granosik, Grzegorz, and Cybulski, Bartłomiej
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ENERGY consumption , *MOBILE robots , *ECONOMIC forecasting , *ENERGY management , *ENERGY levels (Quantum mechanics) , *MAINTENANCE costs - Abstract
The growing significance of mobile robots in a full spectrum of areas of life creates new challenges and opportunities in robotics. One critical aspect to consider is energy utilization, as accurate prediction plays a vital role in a robot's reliability and safety. Furthermore, precise prediction offers economic advantages, particularly for robotic fleets, where energy management systems can optimize maintenance costs and operational efficiency. The following review describes the state of the art of energy usage prediction for different types of mobile robots, highlights current trends, and analyses algorithms' complexity (in implementation and execution), accuracy, and universality. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
47. Visual-Aided Obstacle Climbing by Modular Snake Robot †.
- Author
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Koike, Carla Cavalcante, Viana, Dianne Magalhães, Yudi, Jones, Batista, Filipe Aziz, Costa, Arthur, Carvalho, Vinícius, and Rocha, Thiago
- Subjects
- *
IMAGE processing , *MOBILE robots , *ROBOTS - Abstract
Snake robots, also known as apodal robots, are among the most common and versatile modular robots. Primarily due to their ability to move in different patterns, they can evolve in scenarios with several constraints, some of them hardly accessible to other robot configurations. This paper deals with a specific environment constraint where the robot needs to climb a prismatic obstacle, similar to a step. The objective is to carry out simulations of this function, before implementing it in the physical model. To this end, we propose two different algorithms, parameterized by the obstacle dimensions determined by image processing, and both are evaluated in simulated experiments. The results show that both algorithms are viable for testing in real robots, although more complex scenarios still need to be further studied. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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48. Dynamic Cooperative Communications with Mutual Information Accumulation for Mobile Robots in Industrial Internet of Things.
- Author
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Sun, Daoyuan, Liu, Zefan, and Zhang, Xinming
- Subjects
- *
INDUSTRIAL robots , *INTERNET of things , *WIRELESS Internet , *MOBILE robots , *TIME complexity , *HEURISTIC algorithms , *WIRELESS sensor networks - Abstract
Mobile robots play an important role in the industrial Internet of Things (IIoT); they need effective mutual communication between the cloud and themselves when they move in a factory. By using the sensor nodes existing in the IIoT environment as relays, mobile robots and the cloud can communicate through multiple hops. However, the mobility and delay sensitivity of mobile robots bring new challenges. In this paper, we propose a dynamic cooperative transmission algorithm with mutual information accumulation to cope with these two challenges. By using rateless coding, nodes can reduce the delay caused by retransmission under poor channel conditions. With the help of mutual information accumulation, nodes can accumulate information faster and reduce delay. We propose a two-step dynamic algorithm, which can obtain the current routing path with low time complexity. The simulation results show that our algorithm is better than the existing heuristic algorithm in terms of delay. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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49. Research on Mobile Robot Navigation Method Based on Semantic Information.
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Sun, Ruo-Huai, Zhao, Xue, Wu, Cheng-Dong, Zhang, Lei, and Zhao, Bin
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DEEP learning , *MOBILE robots , *INTERPOLATION algorithms , *MACHINE learning , *POINT cloud , *ROBOT motion , *GLOBAL optimization , *INTERPOLATION - Abstract
This paper proposes a solution to the problem of mobile robot navigation and trajectory interpolation in dynamic environments with large scenes. The solution combines a semantic laser SLAM system that utilizes deep learning and a trajectory interpolation algorithm. The paper first introduces some open-source laser SLAM algorithms and then elaborates in detail on the general framework of the SLAM system used in this paper. Second, the concept of voxels is introduced into the occupation probability map to enhance the ability of local voxel maps to represent dynamic objects. Then, in this paper, we propose a PointNet++ point cloud semantic segmentation network combined with deep learning algorithms to extract deep features of dynamic point clouds in large scenes and output semantic information of points on static objects. A descriptor of the global environment is generated based on its semantic information. Closed-loop completion of global map optimization is performed to reduce cumulative error. Finally, T-trajectory interpolation is utilized to ensure the motion performance of the robot and improve the smooth stability of the robot trajectory. The experimental results indicate that the combination of the semantic laser SLAM system with deep learning and the trajectory interpolation algorithm proposed in this paper yields better graph-building and loop-closure effects in large scenes at SIASUN large scene campus. The use of T-trajectory interpolation ensures vibration-free and stable transitions between target points. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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50. BinVPR: Binary Neural Networks towards Real-Valued for Visual Place Recognition.
- Author
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Wang, Junshuai, Han, Junyu, Dong, Ruifang, and Kan, Jiangming
- Subjects
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CONVOLUTIONAL neural networks , *COMPUTER vision , *MOBILE robots , *MOBILE operating systems - Abstract
Visual Place Recognition (VPR) aims to determine whether a robot or visual navigation system locates in a previously visited place using visual information. It is an essential technology and challenging problem in computer vision and robotic communities. Recently, numerous works have demonstrated that the performance of Convolutional Neural Network (CNN)-based VPR is superior to that of traditional methods. However, with a huge number of parameters, large memory storage is necessary for these CNN models. It is a great challenge for mobile robot platforms equipped with limited resources. Fortunately, Binary Neural Networks (BNNs) can reduce memory consumption by converting weights and activation values from 32-bit into 1-bit. But current BNNs always suffer from gradients vanishing and a marked drop in accuracy. Therefore, this work proposed a BinVPR model to handle this issue. The solution is twofold. Firstly, a feature restoration strategy was explored to add features into the latter convolutional layers to further solve the gradient-vanishing problem during the training process. Moreover, we identified two principles to address gradient vanishing: restoring basic features and restoring basic features from higher to lower layers. Secondly, considering the marked drop in accuracy results from gradient mismatch during backpropagation, this work optimized the combination of binarized activation and binarized weight functions in the Larq framework, and the best combination was obtained. The performance of BinVPR was validated on public datasets. The experimental results show that it outperforms state-of-the-art BNN-based approaches and full-precision networks of AlexNet and ResNet in terms of both recognition accuracy and model size. It is worth mentioning that BinVPR achieves the same accuracy with only 1% and 4.6% model sizes of AlexNet and ResNet. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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