Robotica最新文献_第2页

Design of a traction neck brace with two degrees-of-freedom via a novel architecture of a spatial parallel mechanism 通过空间并联机构的新结构设计具有两个自由度的牵引颈托

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724000882

Jingzong Zhou, Priya Kulkarni, Xincheng Zhao, Sunil K. Agrawal

Traction of the head-neck is important in the treatment of patients suffering from neck pain due to degeneration of the intervertebral discs. Conventional neck traction is provided manually by experienced physical therapists who maintain a desired orientation of the head-neck relative to the trunk while applying the traction. It is postulated that innovative designs of neck exoskeletons can provide the same function both flexibly and accurately. This article presents a novel architecture of a parallel mechanism whose base sits on the human shoulders with 4 parallel chains, each chain having a revolute-revolute-universal-revolute (RRUR) structure, while the end-effector is connected rigidly to the human head. Each chain has five degrees-of-freedom (DOF) and applies a constraint on the motion of the end-effector. As a result, this parallel mechanism allows two DOFs to the end-effector. These are (i) forward flexion or lateral bending of the head and (ii) vertical translation. An important motivation for the current design with RRUR structure is to characterize the range of forward flexion/lateral bending of the head-neck with this structure and the vertical translation to the end-effector. A physical prototype was constructed and tested to evaluate the performance of this mechanism in hardware for the proposed application.

头颈部牵引对于治疗因椎间盘退化而导致的颈部疼痛患者非常重要。传统的颈部牵引是由经验丰富的理疗师手动进行的，他们在牵引时会保持头颈部相对于躯干的理想方向。据推测，创新设计的颈部外骨骼可以灵活而准确地提供相同的功能。本文介绍了一种新颖的并联机构结构，该机构的基座位于人体肩部，有 4 条并联链，每条链都具有旋转-通用-旋转（RRUR）结构，而末端执行器则与人体头部刚性连接。每条链都有五个自由度（DOF），并对末端执行器的运动施加约束。因此，这种平行机构允许末端执行器有两个自由度。这两个自由度分别是：(i) 头部前屈或侧弯；(ii) 垂直平移。目前采用 RRUR 结构设计的一个重要动机是确定采用这种结构的头颈部前屈/侧弯范围以及到末端执行器的垂直平移。我们制作并测试了一个物理原型，以评估该机构在拟议应用中的硬件性能。

{"title":"Design of a traction neck brace with two degrees-of-freedom via a novel architecture of a spatial parallel mechanism","authors":"Jingzong Zhou, Priya Kulkarni, Xincheng Zhao, Sunil K. Agrawal","doi":"10.1017/s0263574724000882","DOIUrl":"https://doi.org/10.1017/s0263574724000882","url":null,"abstract":"Traction of the head-neck is important in the treatment of patients suffering from neck pain due to degeneration of the intervertebral discs. Conventional neck traction is provided manually by experienced physical therapists who maintain a desired orientation of the head-neck relative to the trunk while applying the traction. It is postulated that innovative designs of neck exoskeletons can provide the same function both flexibly and accurately. This article presents a novel architecture of a parallel mechanism whose base sits on the human shoulders with 4 parallel chains, each chain having a revolute-revolute-universal-revolute (RRUR) structure, while the end-effector is connected rigidly to the human head. Each chain has five degrees-of-freedom (DOF) and applies a constraint on the motion of the end-effector. As a result, this parallel mechanism allows two DOFs to the end-effector. These are (i) forward flexion or lateral bending of the head and (ii) vertical translation. An important motivation for the current design with RRUR structure is to characterize the range of forward flexion/lateral bending of the head-neck with this structure and the vertical translation to the end-effector. A physical prototype was constructed and tested to evaluate the performance of this mechanism in hardware for the proposed application.","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A pixel-level grasp detection method based on Efficient Grasp Aware Network 基于高效抓取感知网络的像素级抓取检测方法

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724001358

Haonan Xi, Shaodong Li, Xi Liu

This work proposes a novel grasp detection method, the Efficient Grasp Aware Network (EGA-Net), for robotic visual grasp detection. Our method obtains semantic information for grasping through feature extraction. It efficiently obtains feature channel weights related to grasping tasks through the constructed ECA-ResNet module, which can smooth the network’s learning. Meanwhile, we use concatenation to obtain low-level features with rich spatial information. Our method inputs an RGB-D image and outputs the grasp poses and their quality score. The EGA-Net is trained and tested on the Cornell and Jacquard datasets, and we achieve 98.9% and 95.8% accuracy, respectively. The proposed method only takes 24 ms for real-time performance to process an RGB-D image. Moreover, our method achieved better results in the comparison experiment. In the real-world grasp experiments, we use a 6-degree of freedom (DOF) UR-5 robotic arm to demonstrate its robust grasping of unseen objects in various scenes. We also demonstrate that our model can successfully grasp different types of objects without any processing in advance. The experiment results validate our model’s exceptional robustness and generalization.

本研究提出了一种用于机器人视觉抓取检测的新型抓取检测方法--高效抓取感知网络（EGA-Net）。我们的方法通过特征提取获得抓取的语义信息。它通过构建的 ECA-ResNet 模块有效地获得与抓取任务相关的特征通道权重，从而使网络的学习更加平滑。同时，我们利用串联法获得了具有丰富空间信息的低层次特征。我们的方法输入 RGB-D 图像并输出抓取姿势及其质量得分。EGA 网络在康奈尔和 Jacquard 数据集上进行了训练和测试，准确率分别达到 98.9% 和 95.8%。所提出的方法处理 RGB-D 图像的实时性仅需 24 毫秒。此外，我们的方法在对比实验中取得了更好的结果。在实际抓取实验中，我们使用了 6 自由度（DOF）的 UR-5 机械臂，展示了它在各种场景中对未知物体的鲁棒抓取能力。我们还证明，我们的模型可以在不预先进行任何处理的情况下成功抓取不同类型的物体。实验结果验证了我们的模型具有卓越的鲁棒性和通用性。

{"title":"A pixel-level grasp detection method based on Efficient Grasp Aware Network","authors":"Haonan Xi, Shaodong Li, Xi Liu","doi":"10.1017/s0263574724001358","DOIUrl":"https://doi.org/10.1017/s0263574724001358","url":null,"abstract":"This work proposes a novel grasp detection method, the Efficient Grasp Aware Network (EGA-Net), for robotic visual grasp detection. Our method obtains semantic information for grasping through feature extraction. It efficiently obtains feature channel weights related to grasping tasks through the constructed ECA-ResNet module, which can smooth the network’s learning. Meanwhile, we use concatenation to obtain low-level features with rich spatial information. Our method inputs an RGB-D image and outputs the grasp poses and their quality score. The EGA-Net is trained and tested on the Cornell and Jacquard datasets, and we achieve 98.9% and 95.8% accuracy, respectively. The proposed method only takes 24 ms for real-time performance to process an RGB-D image. Moreover, our method achieved better results in the comparison experiment. In the real-world grasp experiments, we use a 6-degree of freedom (DOF) UR-5 robotic arm to demonstrate its robust grasping of unseen objects in various scenes. We also demonstrate that our model can successfully grasp different types of objects without any processing in advance. The experiment results validate our model’s exceptional robustness and generalization.","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Type synthesis of a new parallel mechanism with complete separation of constraints and drives 完全分离约束和驱动的新型并行机制的类型合成

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724001346

Yu Wang, Can Qiu, Xiaoyu He, Jiabin Wu, Yundou Xu, Yongsheng Zhao

Currently, there is an increasing demand for parallel mechanisms with fewer inputs and more outputs in aerospace, antennas, and recreational facilities. Therefore, this paper proposes a new parallel mechanism (PM) with a separation of constraints and drives, facilitating centralized drive management. Based on screw theory, the type synthesis of new parallel mechanisms with 3T (T representing translation), 3R (R representing revolute), 2T1R, and 2R1T is proposed. Three-degree-of-freedom (3-DOF) parallel mechanisms with fewer inputs and multiple outputs are proposed. Taking the 3RPS-PPPS parallel mechanism as an example, the closed-loop vector method is employed to solve for the lengths of actuated branches. A complete Jacobi matrix is constructed. The motion/force transmission performance of the 3RRS/PPPS parallel mechanism is better than the 3RRS parallel mechanism. Centralized management of drive branches greatly reduces the number of drives, making maintenance and repair easier. It has many application scenarios in antennas, recreational facilities, and other occasions.

目前，航空航天、天线和娱乐设施等领域对投入少、产出多的并联机构的需求日益增长。因此，本文提出了一种约束与驱动分离的新型并联机构（PM），便于对驱动进行集中管理。基于螺杆理论，提出了 3T（T 代表平移）、3R（R 代表反转）、2T1R 和 2R1T 新型并联机构的类型合成。提出了少输入多输出的三自由度（3-DOF）并联机构。以 3RPS-PPPS 并联机构为例，采用闭环矢量法求解驱动分支的长度。构建了一个完整的雅可比矩阵。3RRS/PPPS 并联机构的运动/力传递性能优于 3RRS 并联机构。对驱动分支的集中管理大大减少了驱动的数量，使维护和维修变得更加容易。它在天线、娱乐设施和其他场合有很多应用场景。

引用次数: 0

MonoVisual3DFilter: 3D tomatoes’ localisation with monocular cameras using histogram filters MonoVisual3DFilter：使用直方图滤波器用单目摄像头进行三维番茄定位

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724000936

Sandro Augusto Costa Magalhães, Filipe Neves dos Santos, António Paulo Moreira, Jorge Manuel Miranda Dias

Performing tasks in agriculture, such as fruit monitoring or harvesting, requires perceiving the objects’ spatial position. RGB-D cameras are limited under open-field environments due to lightning interferences. So, in this study, we state to answer the research question: “How can we use and control monocular sensors to perceive objects’ position in the 3D task space?” Towards this aim, we approached histogram filters (Bayesian discrete filters) to estimate the position of tomatoes in the tomato plant through the algorithm MonoVisual3DFilter. Two kernel filters were studied: the square kernel and the Gaussian kernel. The implemented algorithm was essayed in simulation, with and without Gaussian noise and random noise, and in a testbed at laboratory conditions. The algorithm reported a mean absolute error lower than 10 mm in simulation and 20 mm in the testbed at laboratory conditions with an assessing distance of about 0.5 m. So, the results are viable for real environments and should be improved at closer distances.

在农业领域执行水果监测或收获等任务时，需要感知物体的空间位置。由于雷电干扰，RGB-D 摄像机在露天环境下受到限制。因此，在本研究中，我们要回答的研究问题是"我们如何使用和控制单目传感器来感知物体在三维任务空间中的位置？为此，我们采用直方图滤波器（贝叶斯离散滤波器），通过 MonoVisual3DFilter 算法估计番茄植株中番茄的位置。研究了两种核过滤器：方形核和高斯核。在有高斯噪声和随机噪声、无高斯噪声的情况下，以及在实验室条件下的测试平台上，对所实施的算法进行了模拟试验。该算法的平均绝对误差在模拟中低于 10 毫米，在实验室条件下的试验台中低于 20 毫米，评估距离约为 0.5 米。

引用次数: 0

Kinematic analysis and advanced control of a vectored thruster based on 3RRUR parallel manipulator for micro-size AUVs 基于 3RRUR 并联机械手的矢量推进器运动学分析和先进控制，用于微型自动潜航器

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724001280

Tao Liu, Jintao Zhao, Junhao Huang

Autonomous underwater vehicles (AUVs) have played a pivotal role in advancing ocean exploration and exploitation. However, traditional AUVs face limitations when executing missions at minimal or near-zero forward velocities due to the ineffectiveness of their control surfaces, considerably constraining their potential applications. To address this challenge, this paper introduces an innovative vectored thruster system based on a 3RRUR parallel manipulator tailored for micro-sized AUVs. The incorporation of a vectored thruster enhances the performance of micro-sized AUVs when operating at minimal and low forward speeds. A comprehensive exploration of the kinematics of the thrust-vectoring mechanism has been undertaken through theoretical analysis and experimental validation. The findings from theoretical analysis and experimental confirmation unequivocally affirm the feasibility of the devised thrust-vectoring mechanism. The precise control of the vector device is studied using Physics-informed Neural Network and Model Predictive Control (PINN-MPC). Through the adoption of this pioneering thrust-vectoring mechanism rooted in the 3RRUR parallel manipulator, AUVs can efficiently and effectively generate the requisite motion for thrust-vectoring propulsion, overcoming the limitations of traditional AUVs and expanding their potential applications across various domains.

自主潜水器（AUV）在推动海洋勘探和开发方面发挥了关键作用。然而，传统的自动潜航器在以最小或近乎零的前进速度执行任务时，由于其控制面效果不佳而受到限制，从而大大制约了其潜在的应用领域。为了应对这一挑战，本文介绍了一种创新的矢量推进器系统，该系统基于专为微型 AUV 量身定制的 3RRUR 并行操纵器。当微型自动潜航器以最小和较低的前进速度运行时，矢量推进器的加入增强了其性能。通过理论分析和实验验证，对推力矢量机构的运动学进行了全面探索。理论分析和实验验证的结果明确肯定了所设计的推力矢量机构的可行性。利用物理信息神经网络和模型预测控制（PINN-MPC）对矢量装置的精确控制进行了研究。通过采用这种植根于 3RRUR 并行机械手的开创性推力矢量机制，AUV 可以高效率、高效益地产生推力矢量推进所需的运动，从而克服传统 AUV 的局限性，拓展其在各个领域的潜在应用。

{"title":"Kinematic analysis and advanced control of a vectored thruster based on 3RRUR parallel manipulator for micro-size AUVs","authors":"Tao Liu, Jintao Zhao, Junhao Huang","doi":"10.1017/s0263574724001280","DOIUrl":"https://doi.org/10.1017/s0263574724001280","url":null,"abstract":"Autonomous underwater vehicles (AUVs) have played a pivotal role in advancing ocean exploration and exploitation. However, traditional AUVs face limitations when executing missions at minimal or near-zero forward velocities due to the ineffectiveness of their control surfaces, considerably constraining their potential applications. To address this challenge, this paper introduces an innovative vectored thruster system based on a 3RRUR parallel manipulator tailored for micro-sized AUVs. The incorporation of a vectored thruster enhances the performance of micro-sized AUVs when operating at minimal and low forward speeds. A comprehensive exploration of the kinematics of the thrust-vectoring mechanism has been undertaken through theoretical analysis and experimental validation. The findings from theoretical analysis and experimental confirmation unequivocally affirm the feasibility of the devised thrust-vectoring mechanism. The precise control of the vector device is studied using Physics-informed Neural Network and Model Predictive Control (PINN-MPC). Through the adoption of this pioneering thrust-vectoring mechanism rooted in the 3RRUR parallel manipulator, AUVs can efficiently and effectively generate the requisite motion for thrust-vectoring propulsion, overcoming the limitations of traditional AUVs and expanding their potential applications across various domains.","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of abnormal gait behavior of lower limbs based on depth vision 基于深度视觉的下肢异常步态行为预测

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724000948

Tie Liu, Dianchun Bai, Hongyu Yi, Hiroshi Yokoi

As a kind of lower-limb motor assistance device, the intelligent walking aid robot plays an essential role in helping people with lower-limb diseases to carry out rehabilitation walking training. In order to enhance the safety performance of the lower-limb walking aid robot, this study proposes a deep vision-based abnormal lower-limb gait prediction model construction method for the problem of abnormal gait prediction of patients’ lower limbs. The point cloud depth vision technique is used to acquire lower-limb motion data, and a multi-posture angular prediction model is trained using long and short-term memory networks to build a model of the user’s lower-limb posture characteristics during normal walking as well as a real-time lower-limb motion prediction model. The experimental results indicate that the proposed lower-limb abnormal behavior prediction model is able to achieve a 97.4% prediction rate of abnormal lower-limb movements within 150 ms. Additionally, the model demonstrates strong generalization ability in practical applications. This paper proposes further ideas to enhance the safety performance of lower-limb rehabilitation robot use for patients with lower-limb disabilities.

智能助行机器人作为一种下肢运动辅助装置，在帮助下肢疾病患者进行康复行走训练中发挥着至关重要的作用。为了提高下肢助行机器人的安全性能，本研究针对患者下肢异常步态预测问题，提出了一种基于深度视觉的下肢异常步态预测模型构建方法。采用点云深度视觉技术获取下肢运动数据，利用长短期记忆网络训练多姿态角度预测模型，建立用户正常行走时的下肢姿态特征模型以及实时下肢运动预测模型。实验结果表明，所提出的下肢异常行为预测模型能够在 150 毫秒内实现 97.4% 的下肢异常运动预测率。此外，该模型在实际应用中还表现出很强的泛化能力。本文提出了进一步提高下肢残疾患者使用下肢康复机器人安全性能的思路。

{"title":"Prediction of abnormal gait behavior of lower limbs based on depth vision","authors":"Tie Liu, Dianchun Bai, Hongyu Yi, Hiroshi Yokoi","doi":"10.1017/s0263574724000948","DOIUrl":"https://doi.org/10.1017/s0263574724000948","url":null,"abstract":"As a kind of lower-limb motor assistance device, the intelligent walking aid robot plays an essential role in helping people with lower-limb diseases to carry out rehabilitation walking training. In order to enhance the safety performance of the lower-limb walking aid robot, this study proposes a deep vision-based abnormal lower-limb gait prediction model construction method for the problem of abnormal gait prediction of patients’ lower limbs. The point cloud depth vision technique is used to acquire lower-limb motion data, and a multi-posture angular prediction model is trained using long and short-term memory networks to build a model of the user’s lower-limb posture characteristics during normal walking as well as a real-time lower-limb motion prediction model. The experimental results indicate that the proposed lower-limb abnormal behavior prediction model is able to achieve a 97.4% prediction rate of abnormal lower-limb movements within 150 ms. Additionally, the model demonstrates strong generalization ability in practical applications. This paper proposes further ideas to enhance the safety performance of lower-limb rehabilitation robot use for patients with lower-limb disabilities.","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

RGB-D visual odometry by constructing and matching features at superpixel level 通过构建和匹配超像素级特征进行 RGB-D 视觉里程测量

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724000985

Meiyi Yang, Junlin Xiong, Youfu Li

Visual odometry (VO) is a key technology for estimating camera motion from captured images. In this paper, we propose a novel RGB-D visual odometry by constructing and matching features at the superpixel level that represents better adaptability in different environments than state-of-the-art solutions. Superpixels are content-sensitive and perform well in information aggregation. They could thus characterize the complexity of the environment. Firstly, we designed the superpixel-based feature SegPatch and its corresponding 3D representation MapPatch. By using the neighboring information, SegPatch robustly represents its distinctiveness in various environments with different texture densities. Due to the inclusion of depth measurement, the MapPatch constructs the scene structurally. Then, the distance between SegPatches is defined to characterize the regional similarity. We use the graph search method in scale space for searching and matching. As a result, the accuracy and efficiency of matching process are improved. Additionally, we minimize the reprojection error between the matched SegPatches and estimate camera poses through all these correspondences. Our proposed VO is evaluated on the TUM dataset both quantitatively and qualitatively, showing good balance to adapt to the environment under different realistic conditions.

视觉轨迹测量（VO）是根据捕捉到的图像估计摄像机运动的一项关键技术。在本文中，我们提出了一种新颖的 RGB-D 视觉里程测量法，它通过在超像素级别构建和匹配特征，与最先进的解决方案相比，在不同环境下具有更好的适应性。超像素对内容敏感，在信息聚合方面表现出色。因此，它们可以描述环境的复杂性。首先，我们设计了基于超像素的特征 SegPatch 及其相应的三维表示 MapPatch。通过使用邻近信息，SegPatch 可以在不同纹理密度的环境中稳健地表示其独特性。由于包含了深度测量，MapPatch 从结构上构建了场景。然后，定义 SegPatch 之间的距离来描述区域相似性。我们在比例空间中使用图搜索法进行搜索和匹配。因此，匹配过程的准确性和效率都得到了提高。此外，我们将匹配的 SegPatches 之间的重投影误差降至最低，并通过所有这些对应关系来估计摄像机的姿势。我们提出的 VO 在 TUM 数据集上进行了定量和定性评估，显示出在不同现实条件下适应环境的良好平衡性。

{"title":"RGB-D visual odometry by constructing and matching features at superpixel level","authors":"Meiyi Yang, Junlin Xiong, Youfu Li","doi":"10.1017/s0263574724000985","DOIUrl":"https://doi.org/10.1017/s0263574724000985","url":null,"abstract":"Visual odometry (VO) is a key technology for estimating camera motion from captured images. In this paper, we propose a novel RGB-D visual odometry by constructing and matching features at the superpixel level that represents better adaptability in different environments than state-of-the-art solutions. Superpixels are content-sensitive and perform well in information aggregation. They could thus characterize the complexity of the environment. Firstly, we designed the superpixel-based feature SegPatch and its corresponding 3D representation MapPatch. By using the neighboring information, SegPatch robustly represents its distinctiveness in various environments with different texture densities. Due to the inclusion of depth measurement, the MapPatch constructs the scene structurally. Then, the distance between SegPatches is defined to characterize the regional similarity. We use the graph search method in scale space for searching and matching. As a result, the accuracy and efficiency of matching process are improved. Additionally, we minimize the reprojection error between the matched SegPatches and estimate camera poses through all these correspondences. Our proposed VO is evaluated on the TUM dataset both quantitatively and qualitatively, showing good balance to adapt to the environment under different realistic conditions.","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Customized stiffness control strategy for a six-bar linkage-based gait rehabilitation robot 基于六杆联动的步态康复机器人的定制刚度控制策略

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-18 DOI: 10.1017/s0263574724001425

Akim Kapsalyamov, Shahid Hussain, Roland Goecke, Nicholas A.T. Brown, Prashant K. Jamwal

Lower limb rehabilitation robots based on linkage-based mechanisms have recently drawn significant attention in the field due to their numerous advantages. The control of previously proposed linkage-based gait rehabilitation robotic orthoses has been achieved using constant speed control without consideration for the interaction forces. However, such an approach can be harmful to people with stroke since the level of disability varies among individuals, and it may cause potential injuries when excessive force is applied by the robot. To overcome this limitation and improve the rehabilitation process, it is necessary to recognize the force exerted by the person during walking and adjust the robot’s assistive torque accordingly, to provide synchronized motion. Thus, in this work, a human-cooperative approach based on a stiffness control strategy for the six-bar linkage-based gait rehabilitation robot is presented. The proposed methodology can serve as a solid foundation for developing a human-cooperative approach for linkage-based lower limb rehabilitation robotic orthoses. The control was validated and tested with eight healthy human subjects. As a result, customized robotic assistance with this mechanism can be provided during training to meet the individual needs of stroke patients, which can lead to increased engagement and contribution, thus improving treatment outcomes.

基于联动机构的下肢康复机器人因其众多优势，最近在该领域引起了极大关注。之前提出的基于联动机构的步态康复机器人矫形器的控制是通过恒速控制实现的，没有考虑相互作用力。然而，这种方法可能会对中风患者造成伤害，因为每个人的残疾程度不同，而且当机器人施加过大的力时，可能会造成潜在的伤害。为了克服这一局限并改善康复过程，有必要识别人在行走过程中施加的力，并相应调整机器人的辅助力矩，以提供同步运动。因此，本研究提出了一种基于六杆联动步态康复机器人刚度控制策略的人类合作方法。所提出的方法可作为开发基于联动的下肢康复机器人矫形器的人类合作方法的坚实基础。该控制方法通过八名健康人体受试者进行了验证和测试。因此，可以在训练过程中利用该机制提供定制的机器人辅助，以满足中风患者的个性化需求，从而提高参与度和贡献度，改善治疗效果。

{"title":"Customized stiffness control strategy for a six-bar linkage-based gait rehabilitation robot","authors":"Akim Kapsalyamov, Shahid Hussain, Roland Goecke, Nicholas A.T. Brown, Prashant K. Jamwal","doi":"10.1017/s0263574724001425","DOIUrl":"https://doi.org/10.1017/s0263574724001425","url":null,"abstract":"Lower limb rehabilitation robots based on linkage-based mechanisms have recently drawn significant attention in the field due to their numerous advantages. The control of previously proposed linkage-based gait rehabilitation robotic orthoses has been achieved using constant speed control without consideration for the interaction forces. However, such an approach can be harmful to people with stroke since the level of disability varies among individuals, and it may cause potential injuries when excessive force is applied by the robot. To overcome this limitation and improve the rehabilitation process, it is necessary to recognize the force exerted by the person during walking and adjust the robot’s assistive torque accordingly, to provide synchronized motion. Thus, in this work, a human-cooperative approach based on a stiffness control strategy for the six-bar linkage-based gait rehabilitation robot is presented. The proposed methodology can serve as a solid foundation for developing a human-cooperative approach for linkage-based lower limb rehabilitation robotic orthoses. The control was validated and tested with eight healthy human subjects. As a result, customized robotic assistance with this mechanism can be provided during training to meet the individual needs of stroke patients, which can lead to increased engagement and contribution, thus improving treatment outcomes.","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fixed-time control of teleoperation systems based on adaptive event-triggered communication and force estimators 基于自适应事件触发通信和力估算器的远距操作系统固定时间控制

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-16 DOI: 10.1017/s0263574724001310

Xia Liu, Hui Wen

A fixed-time control strategy based on adaptive event-triggered communication and force estimators is proposed for a class of teleoperation systems with time-varying delays and limited bandwidth. Two force estimators are designed to estimate the operator force and environment force instead of force sensors. With the position, velocity, force estimate signals, and triggering error, an adaptive event-triggered scheme is designed, which automatically adjusts the triggering thresholds to reduce the access frequency of the communication network. With the state information transmitted at the moment of event triggering while considering the time-varying delays, a fixed-time sliding mode controller is designed to achieve the position and force tracking. The stability of the system and the convergence of tracking error within a fixed time are mathematically proved. Experimental results indicate that the control strategy can significantly reduce the information transmission, enhance the bandwidth utilization, and ensure the convergence of tracking error within a fixed time for teleoperation systems.

针对一类具有时变延迟和有限带宽的远程操作系统，提出了一种基于自适应事件触发通信和力估计器的固定时间控制策略。设计了两个力估算器来代替力传感器估算操作员力和环境力。利用位置、速度、力估计信号和触发误差，设计了一种自适应事件触发方案，可自动调整触发阈值以降低通信网络的访问频率。利用事件触发时刻传输的状态信息，同时考虑时变延迟，设计了一种固定时间滑动模式控制器，以实现位置和力跟踪。系统的稳定性和跟踪误差在固定时间内的收敛性得到了数学证明。实验结果表明，该控制策略可显著减少信息传输，提高带宽利用率，并确保远程操纵系统的跟踪误差在固定时间内收敛。

引用次数: 0

Incipient fault diagnosis for robot manipulators based on evolution of friction characteristics in transmission components 基于传动部件摩擦特性演变的机器人机械手初期故障诊断

IF 2.7 4区计算机科学 Q3 ROBOTICS

Robotica

Pub Date : 2024-09-16 DOI: 10.1017/s0263574724001450

Xing Zhou, Shifeng Huang, Yaoqi Xian, Huicheng Zhou, Wenbin Deng, Jian Zhou

The tribological behavior can be informative about the incipient faults of robot manipulators. This study explores the evolution of friction characteristics from cold start to thermal equilibrium through a series of steady-state friction experiments. Based on these experimental observations, a friction-based fault diagnosis framework is proposed. The fault diagnosis process primarily involves defining the healthy state, decomposing friction curves and their features, and anomaly detection. Given the dependence of friction characteristics on different sources of faults, the parameters of steady-state experimental friction model are divided into two categories: one associated with contact interactions and the other related to non-contact regimes. Subsequently, confidence regions corresponding to distinguishable friction characteristics are independently constructed. These regions encapsulate the statistical description of the healthy state, characterized by mean values and the covariance of the friction characteristic parameter vectors during the unloaded state. In addition, we conduct experiments that consider the influence of applied loads on friction behavior. These experiments serve as a test set for comparison against nominal statistics. Leveraging the similarity between the effects of wear and load on friction, we introduce equivalent load thresholds to assess the severity of joint degradation. The results demonstrate the feasibility of employing confidence region views based on friction characteristic classification for fault detection and isolation.

摩擦学行为可以为机器人机械手的初期故障提供信息。本研究通过一系列稳态摩擦实验，探讨了摩擦特性从冷启动到热平衡的演变过程。基于这些实验观察结果，提出了基于摩擦的故障诊断框架。故障诊断过程主要包括定义健康状态、分解摩擦曲线及其特征以及异常检测。考虑到摩擦特性对不同故障源的依赖性，稳态实验摩擦模型的参数被分为两类：一类与接触相互作用相关，另一类与非接触状态相关。随后，独立构建了与可区分的摩擦特性相对应的置信区域。这些区域囊括了健康状态的统计描述，其特征是无负荷状态下摩擦特性参数向量的平均值和协方差。此外，我们还进行了考虑外加载荷对摩擦行为影响的实验。这些实验可作为与名义统计数据进行比较的测试集。利用磨损和载荷对摩擦影响的相似性，我们引入了等效载荷阈值来评估关节退化的严重程度。结果证明了基于摩擦特性分类的置信区间视图用于故障检测和隔离的可行性。

{"title":"Incipient fault diagnosis for robot manipulators based on evolution of friction characteristics in transmission components","authors":"Xing Zhou, Shifeng Huang, Yaoqi Xian, Huicheng Zhou, Wenbin Deng, Jian Zhou","doi":"10.1017/s0263574724001450","DOIUrl":"https://doi.org/10.1017/s0263574724001450","url":null,"abstract":"<p>The tribological behavior can be informative about the incipient faults of robot manipulators. This study explores the evolution of friction characteristics from cold start to thermal equilibrium through a series of steady-state friction experiments. Based on these experimental observations, a friction-based fault diagnosis framework is proposed. The fault diagnosis process primarily involves defining the healthy state, decomposing friction curves and their features, and anomaly detection. Given the dependence of friction characteristics on different sources of faults, the parameters of steady-state experimental friction model are divided into two categories: one associated with contact interactions and the other related to non-contact regimes. Subsequently, confidence regions corresponding to distinguishable friction characteristics are independently constructed. These regions encapsulate the statistical description of the healthy state, characterized by mean values and the covariance of the friction characteristic parameter vectors during the unloaded state. In addition, we conduct experiments that consider the influence of applied loads on friction behavior. These experiments serve as a test set for comparison against nominal statistics. Leveraging the similarity between the effects of wear and load on friction, we introduce equivalent load thresholds to assess the severity of joint degradation. The results demonstrate the feasibility of employing confidence region views based on friction characteristic classification for fault detection and isolation.</p>","PeriodicalId":49593,"journal":{"name":"Robotica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0