检索结果-内蒙古大学图书馆

Mediterranean Conference on Control and Automation (MED)

作者： Mario A.V. Saucedo Nikolaos Stathoulopoulos Vidya Sumathy Christoforos Kanellakis George Nikolakopoulos Department of Computer Electrical and Space Engineering Robotics & AI Group Luleå University of Technology Luleå Sweden

ISBN: (数字)9798350395440

ISBN: (纸本)9798350395457

Object detection and global localization play a crucial role in robotics, spanning across a great spectrum of applications from autonomous cars to multi-layered 3D Scene Graphs for semantic scene understanding. This article proposes $BOX3D$ , a novel multi-modal and lightweight scheme for localizing objects of interest by fusing the information from RGB camera and 3D LiDAR. $BOX3D$ is structured around a three-layered architecture, building up from the local perception of the incoming sequential sensor data to the global perception refinement that covers for outliers and the general consistency of each object's observation. More specifically, the first layer handles the low-level fusion of camera and LiDAR data for initial 3D bounding box extraction. The second layer converts each LiDAR's scan 3D bounding boxes to the world coordinate frame and applies a spatial pairing and merging mechanism to maintain the uniqueness of objects observed from different viewpoints. Finally, BOX3D integrates the third layer that supervises the consistency of the results on the global map iteratively, using a point-to-voxel comparison for identifying all points in the global map that belong to the object. Benchmarking results of the proposed novel architecture are showcased in multiple experimental trials on public state-of-the-art large-scale dataset of urban environments.

关键词： Location awareness Point cloud compression Three-dimensional displays Laser radar Urban areas Merging Object detection

来源：评论

学校读者我要写书评

暂无评论

Body-aware Local Navigation for Asymmetric Holonomic Robots using Control Barrier Functions

Body-aware Local Navigation for Asymmetric Holonomic Robots ...

引用

European Control Conference (ECC)

作者： Akshit Saradagi Scott Fredriksson Anton Koval George Nikolakopoulos Department of Computer Science Electrical and Space Engineering Robotics and AI Group Luleå University of Technology Sweden

ISBN: (数字)9783907144107

ISBN: (纸本)9798331540920

In this article, we propose a body-aware local navigation strategy for asymmetric holonomic robots for collision-free navigation in narrow pathways with sharp turns. In such scenarios, a robot with non-circular or asymmetric footprint that is comparable to the dimension of the pathways collides with walls when tracking Voronoi paths or risk-aware paths. This problem is addressed in this article through a novel multi-control barrier functions (CBF) based control strategy that achieves the objective of safe collision-free maneuvering at sharp turns. The proposed method is significantly computationally light in comparison to approaches based on model predictive control and online occupancy-grid based free-space and collision detection. In the proposed approach, a minimal set of parameters that characterize a sharp turn and the robot footprint are used to define six control barrier functions that define safe and unsafe regions of operation for a robot. A quadratic programming based CBF safety filter is designed that takes a nominal goal-reaching control as input and returns a minimally-deviating output that enforces the control barrier constraints and renders the safe set forward invariant throughout the turning maneuver. The three kinematic control inputs of the holonomic robot are shared in a conflict-free manner among the six control barrier constraints. The proposed local navigation approach was thoroughly validated in multiple scenarios in a simulated environment, where a robot with asymmetric footprint achieves collision-free maneuvering along multiple sharp turns, while respecting the safety and actuation constraints.

关键词： Laser radar Navigation Kinematics Turning Safety Quadratic programming Mobile robots

来源：评论

学校读者我要写书评

暂无评论

RecNet: An Invertible Point Cloud Encoding through Range Image Embeddings for Multi-Robot Map Sharing and Reconstruction

RecNet: An Invertible Point Cloud Encoding through Range Ima...

引用

IEEE International Conference on Robotics and Automation (ICRA)

作者： Nikolaos Stathoulopoulos Mario A.V. Saucedo Anton Koval George Nikolakopoulos Department of Computer Electrical and Space Engineering Robotics and AI Group Luleå University of Technology Luleå Sweden

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

In the field of resource-constrained robots and the need for effective place recognition in multi-robotic systems, this article introduces RecNet, a novel approach that concurrently addresses both challenges. The core of RecNet’s methodology involves a transformative process: it projects 3D point clouds into range images, compresses them using an encoder-decoder framework, and subsequently reconstructs the range image, restoring the original point cloud. Additionally, RecNet utilizes the latent vector extracted from this process for efficient place recognition tasks. This approach not only achieves comparable place recognition results but also maintains a compact representation, suitable for sharing among robots to reconstruct their collective maps. The evaluation of RecNet encompasses an array of metrics, including place recognition performance, the structural similarity of the reconstructed point clouds, and the bandwidth transmission advantages, derived from sharing only the latent vectors. Our proposed approach is assessed using both a publicly available dataset and field experiments 1 confirming its efficacy and potential for real-world applications.

关键词： Point cloud compression Measurement Image coding Three-dimensional displays Bandwidth Vectors Multi-robot systems

来源：评论

学校读者我要写书评

暂无评论

Electro-Pneumatic Interface Framework for PAM-based Humanoid Robot Motion Control with EMG

Electro-Pneumatic Interface Framework for PAM-based Humanoid...

引用

Mediterranean Electrotechnical Conference (MELECON)

作者： Nathan Hiruy Vidya Sumathy Jakub Haluska George Nikolakopoulos Department of Computer Electrical and Space Engineering Robotics and AI Group Luleå University of Technology Luleå Sweden

ISBN: (数字)9798350387025

ISBN: (纸本)9798350387032

In this work, a real-time electro-pneumatic interface framework for emulating human muscular motion on a pneumatic-actuated muscle-based robot is presented. Pneumatic-actuated muscles are flexible actuators that contract and expand using pressure input and are widely used in medical and robotic research to generate motions that mimic human muscles. Electromyographic signals that measure the nerve stimulation of the muscles in an organism, can be used to emulate real-time muscular motion in Pneumatic Artificial Muscle based robots. Here, the proposed electro-pneumatic interface framework takes a real-time electromyographic signal as input and outputs corresponding pneumatic signals for actuating the pneumatic artificial muscles. The electromyographic sensors, attached to the human body, pick up the signals during motion, and the software electro-pneumatic interface computes the required differential pressure for the robot’s motion. In this approach, experimental data is used to model the transfer functions between variables such as the electromyographic signal, robot deflection angle, and differential pressure for the pneumatic artificial muscles. The proposed framework is experimentally validated on a humanoid robot made of pneumatic artificial muscles. The simulation and experiment results show the virtues of the proposed methodology.

关键词： Artificial muscles Humanoid robots Pneumatic systems Muscles Robot sensing systems Electromyography Real-time systems

来源：评论

学校读者我要写书评

暂无评论

TFMarker: A Tangible Fiducial Pattern for Enabling Camera-assisted Guided Landing in SubT Environments

TFMarker: A Tangible Fiducial Pattern for Enabling Camera-as...

引用

International Conference on Control, Automation and Systems ( ICCAS)

作者： Mario A. V. Saucedo Akash Patel Niklas Dahlquist Yifan Bai Björn Lindqvist Christoforos Kanellakis George Nikolakopoulos Department of Computer Electrical and Space Engineering Robotics & AI Group Luleå University of Technology Luleå Sweden

ISBN: (数字)9788993215380

ISBN: (纸本)9798331517939

Visual servoing plays a crucial role in robotics, spanning across a great spectrum of applications from autonomous cars to aerial manipulation. This article proposes TFMarker, a novel tangible fiducial pattern for enabling camera-assisted guided landing of UAVs by using the visual features from color markers as the main source of information. TFMarker is structured around a 4-point fiducial marker, allowing for accurate, precise, and consistent pose estimation in different environments and lighting conditions, while also offering resilience to motion blur. The presented detection framework is based on a three-step architecture, where the first step uses Gaussian and color filtering in addition to morphological operation in order to generate a robust detection of the markers. The second step uses the Gift Wrapping Algorithm, to organize the same-color markers based on their relative positioning with respect to the off-color marker. Finally, the Perspective-n-Point optimization problem is solved in order to extract the pose (i.e. position and orientation) of the proposed pattern with respect to the vision sensor. The efficacy of the proposed scheme has been extensively validated in indoor and SubT environments for the task of autonomous landing using a custom-made UAV. The experimental results showcase the performance of the proposed method, which presents a better detection rate in both environments while retaining similar accuracy and precision to the baseline approach. For the video of the experimental evaluation please refer to the following link: https://***/Zh13OObp15Q

关键词： Visualization Accuracy Filtering Color Vision sensors Autonomous aerial vehicles Visual servoing Wrapping Optimization Morphological operations

来源：评论

学校读者我要写书评

暂无评论

D-MARL: A Dynamic Communication-Based Action Space Enhancement for Multi Agent Reinforcement Learning Exploration of Large Scale Unknown Environments

D-MARL: A Dynamic Communication-Based Action Space Enhanceme...

引用

IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Gabriele Calzolari Vidya Sumathy Christoforos Kanellakis George Nikolakopoulos Department of Computer Science Electrical and Space Engineering Robotics and AI Group Luleå University of Technology Sweden

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

In this article, we propose a novel communication-based action space enhancement for the D-MARL exploration algorithm to improve the efficiency of mapping an unknown environment, represented by an occupancy grid map. In general, communication between autonomous systems is crucial when exploring large and unstructured environments. In such real-world scenarios, data transmission is limited and relies heavily on inter-agent proximity and the attributes of the autonomous platforms. In the proposed approach, each agent’s policy is optimized by utilizing the heterogeneous-agent proximal policy optimization algorithm to autonomously choose whether to communicate or explore the environment. To accomplish this, multiple novel reward functions are formulated by integrating inter-agent communication and exploration. The investigated approach aims to increase efficiency and robustness in the mapping process, minimize exploration overlap, and prevent agent collisions. The D-MARL policies trained on different reward functions have been compared to understand the effect of different reward terms on the collaborative attitude of the homogeneous agents. Finally, multiple simulation results are provided to prove the efficacy of the proposed scheme.

关键词： Autonomous systems simulation Merging Employment Collaboration Reinforcement learning Robustness Data communication Optimization Intelligent robots

来源：评论

学校读者我要写书评

暂无评论

Robotic Exploration through Semantic Topometric Mapping

Robotic Exploration through Semantic Topometric Mapping

引用

IEEE International Conference on Robotics and Automation (ICRA)

作者： Scott Fredriksson Akshit Saradagi George Nikolakopoulos Department of Computer Science Robotics and AI Group Electrical and Space Engineering at Luleå University of Technology Sweden

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

In this article, we introduce a novel strategy for robotic exploration in unknown environments using a semantic topometric map. As it will be presented, the semantic topometric map is generated by segmenting the grid map of the currently explored parts of the environment into regions, such as intersections, pathways, dead-ends, and unexplored frontiers, which constitute the structural semantics of an environment. The proposed exploration strategy leverages metric information of the frontier, such as distance and angle to the frontier, similar to existing frameworks, with the key difference being the additional utilization of structural semantic information, such as properties of the intersections leading to frontiers. The algorithm for generating semantic topometric mapping utilized by the proposed method is lightweight, resulting in the method’s online execution being both rapid and computationally efficient. Moreover, the proposed framework can be applied to both structured and unstructured indoor and outdoor environments, which enhances the versatility of the proposed exploration algorithm. We validate our exploration strategy and demonstrate the utility of structural semantics in exploration in two complex indoor environments by utilizing a Turtlebot3 as the robotic agent. Compared to traditional frontier-based methods, our findings indicate that the proposed approach leads to faster exploration and requires less computation time.

关键词： Measurement Laser radar Navigation Semantics Skeleton Iron Indoor environment

来源：评论

学校读者我要写书评

暂无评论

Robotic Exploration through Semantic Topometric Mapping

arXiv

引用

arXiv 2024年

作者： Fredriksson, Scott Saradagi, Akshit Nikolakopoulos, George Robotics and AI group The Department of Computer Science Electrical and Space Engineering Luleå University of Technology Sweden

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

Cloud-Based Scheduling Mechanism for Scalable and Resource-Efficient Centralized Controllers

arXiv

引用

arXiv 2024年

作者： Seisa, Achilleas Santi Satpute, Sumeet Gajanan Nikolakopoulos, George The Robotics and AI Group Department of Computer Electrical and Space Engineering Luleå University of Technology Luleå Sweden

This paper proposes a novel approach to address the challenges of deploying complex robotic software in large-scale systems, i.e., Centralized Nonlinear Model Predictive Controllers (CNMPCs) for multi-agent systems. The proposed approach is based on a Kubernetes-based scheduling mechanism designed to monitor and optimize the operation of CNMPCs, while addressing the scalability limitation of centralized control schemes. By leveraging a cluster in a real-time cloud environment, the proposed mechanism effectively offloads the computational burden of CNMPCs. Through experiments, we have demonstrated the effectiveness and performance of our system, especially in scenarios where the number of robots is subject to change. Our work contributes to the advancement of cloud-based control strategies and lays the foundation for enhanced performance in cloud-controlled robotic systems. © 2024, CC BY.

关键词： Multi agent systems

来源：评论

学校读者我要写书评

暂无评论

Soft Arm-Motor Thrust Characterization for a Pneumatically Actuated Soft Morphing Quadrotor

arXiv

引用

arXiv 2025年

作者： Sumathy, Vidya Haluska, Jakub Nikolokopoulos, George Robotics & AI Group Department of Computer Electrical and Space Engineering Luleå University of Technology LuleåSE-97187 Sweden

In this work, an experimental characterization of the configuration space of a soft, pneumatically actuated morphing quadrotor is presented, with a focus on precise thrust characterization of its flexible arms, considering the effect of downwash. Unlike traditional quadrotors, the soft drone has pneumatically actuated arms, introducing complex, nonlinear interactions between motor thrust and arm deformation, which make precise control challenging. The silicone arms are actuated using differential pressure to achieve flexibility and thus have a variable workspace compared to their fixed counterparts. The deflection of the soft arms during compression and expansion is controlled throughout the flight. However, in real time, the downwash from the motor attached at the tip of the soft arm generates a significant and random disturbance on the arm. This disturbance affects both the desired deflection of the arm and the overall stability of the system. To address this factor, an experimental characterization of the effect of downwash on the deflection angle of the arm is conducted. © 2025, CC BY.

关键词： Pneumatics

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：