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Time-Optimal Trajectory Planning Based on Dynamics for Industrial Robot 5

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Time-Optimal Trajectory Planning Based on Dynamics for Indus...

5th International Conference on Automation, Control and robotics Engineering, CACRE 2020

作者： Wang, Rundong Kong, Minxiu Cheng, Yanchun Castellani, Marco Harbin Institute of Technology State Key Laboratory of Robotics and System School of Mechatronics Engineering Harbin China University of Birmingham Department of Mechanical Engineering Birmingham United Kingdom

ISBN: (纸本)9781728198880

Given the trajectory of the industrial robot in Cartesian space, the existing methods only consider the kinematic constraints when optimizing the time trajectory planning, and ignore the maximum driving ability of the motor, which is likely to cause an overrun alarm and greatly reduce the trajectory accuracy. Therefore, this paper studies the time-optimal trajectory planning algorithm based on dynamics. Firstly, the algorithm discretizes the path, calculates the Cartesian coordinates of each discrete point and the differential about the path length. Then, this algorithm considers the constraints of dynamics and kinematics, uses the principle of linear programming, recursively calculates the upper limit value of speed and the maximum acceleration value at each discrete point, and calculates the speed value at each discrete point and keeps it within its allowable ranges. Finally, this algorithm uses the speed to calculate the corresponding time of each discrete point, and according to the interpolation period, outputs the path position of each period, the position and orientation in the Cartesian space and joint parameters. The MATLAB program is written to verify the feasibility and efficiency of the algorithm. © 2020 IEEE.

关键词： Industrial robots

Joint Counting, Detection and Re-Identification for Multi-Object Tracking

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arXiv 2022年

作者： Ren, Weihong Wu, Denglu Cao, Hui Chen, Xi'ai Han, Zhi Liu, Honghai The School of Mechanical Engineering and Automation State Key Lab of Robotics and Systems Harbin Institute of Technology Shenzhen518055 China The Shenzhen Duorou Intelligent System Co. Ltd. Shenzhen518055 China The School of Electrical Engineering Xi’an Jiaotong University Xi’an710049 China State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Science Beijing110169 China

The recent trend in 2D multiple object tracking (MOT) is jointly solving detection and tracking, where object detection and appearance feature (or motion) are learned simultaneously. Despite competitive performance, in crowded scenes, joint detection and tracking usually fail to find accurate object associations due to missed or false detections. In this paper, we jointly model counting, detection and re-identification in an end-to-end framework, named CountingMOT, tailored for crowded scenes. By imposing mutual object-count constraints between detection and counting, the CountingMOT tries to find a balance between object detection and crowd density map estimation, which can help it to recover missed detections or reject false detections. Our approach is an attempt to bridge the gap of object detection, counting, and re-Identification. This is in contrast to prior MOT methods that either ignore the crowd density and thus are prone to failure in crowded scenes, or depend on local correlations to build a graphical relationship for matching targets. The proposed MOT tracker can perform online and real-time tracking, and achieves the state-of-the-art results on public benchmarks MOT16 (MOTA of 79.7%), MOT17 (MOTA of 81.3%) and MOT20 (MOTA of 78.9%). Source code is available at https://***/weihong9/CountingMOT. Copyright © 2022, The Authors. All rights reserved.

关键词： Object detection

Bipedal Robust Walking on Uneven Footholds: Piecewise Slope LIPM with Discrete Model Predictive Control

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arXiv 2025年

作者： Shi, Yapeng Li, Sishu Wu, Yongqiang Liu, Junjie Leng, Xiaokun Zang, Xizhe Piao, Songhao Faculty of Computing Harbin Institute of Technology Harbin150001 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

This study presents an enhanced theoretical formulation for bipedal hierarchical control frameworks under uneven terrain conditions. Specifically, owing to the inherent limitations of the Linear Inverted Pendulum Model (LIPM) in handling terrain elevation variations, we develop a Piecewise Slope LIPM (PS-LIPM). This innovative model enables dynamic adjustment of the Center of Mass (CoM) height to align with topographical undulations during single-step cycles. Another contribution is proposed a generalized Angular Momentum-based LIPM (G-ALIP) for CoM velocity compensation using Centroidal Angular Momentum (CAM) regulation. Building upon these advancements, we derive the DCM step-to-step dynamics for Model Predictive Control MPC formulation, enabling simultaneous optimization of step position and step duration. A hierarchical control framework integrating MPC with a Whole-Body Controller (WBC) is implemented for bipedal locomotion across uneven stepping stones. The results validate the efficacy of the proposed hierarchical control framework and the theoretical formulation. Copyright © 2025, The Authors. All rights reserved.

关键词： Piecewise linear techniques

Image segmentation network for laparoscopic surgery

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Biomimetic Intelligence and robotics 2025年

作者： Kang Peng Yaoyuan Chang Guodong Lang Jian Xu Yongsheng Gao Jiajun Yin Jie Zhao The State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150000 China Zhongshan Hospital Affiliated to Dalian University Dalian 116000 China

Surgical image segmentation serves as the foundation for laparoscopic surgical navigation technology. The indistinct local features of biological tissues in laparoscopic image pose challenges for image segmentation. To address this issue, we develop an image segmentation network tailored for laparoscopic surgery. Firstly, we introduce the Mixed Attention Enhancement (MAE) module that sequentially conducts the Channel Attention Enhancement (CAE) module and the Global Feature Enhancement (GFE) module linked in series. The CAE module enhances the network’s perception of prominent channels, allowing feature maps to exhibit clear local features. The GFE module is capable of extracting global features from both the height and width dimensions of images and integrating them into three-dimensional features. This enhancement improves the network’s ability to capture global features, thereby facilitating the inference of regions with indistinct local features. Secondly, we propose the Multi-scale Feature Fusion (MFF) module. This module expands the feature map into various scales, further enlarging the network’s receptive field and enhancing perception of features at multiple scales. In addition, we tested the proposed network on the EndoVis 2018 and a human minimally invasive liver resection image segmentation dataset, comparing it against six other advanced image segmentation networks. The comparative test results demonstrate that the proposed network achieves the most advanced performance on both datasets, proving its potential in improving surgical image segmentation outcome. The codes of MAMNet are available at: https://***/Pang1234567/MAMNet .

关键词： Laparoscopic surgery image Medical image segmentation Convolutional neural networks Attention mechanism Feature fusion

Bionic knee joint structure and motion analysis of a lower extremity exoskeleton 4

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Bionic knee joint structure and motion analysis of a lower e...

4th International Conference on robotics and Automation Sciences, ICRAS 2020

作者： Xiao, Yongfei Ji, Xiangjing Wu, Hao Zhai, Xinpeng Fu, Xiaochun Zhao, Jie Institute of Automation Qilu University of Technology Shandong Academic of Science Shandong Provincial Key Laboratory of Robot and Manufacturing Automation Technology Jinan China Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9781728198576

In order to solve the problem of poor human-machine compliance of wearable lower extremity exoskeleton robots, a modified lower extremity exoskeleton with a four-bar mechanism in the knee joint is proposed and analyzed. The advantages of the four-bar mechanism relative to the traditional two-bar hinge structure are explained by analyzing the physiological characteristics of the human knee joint. In addition, the kinematics of traditional and modified lower extremity exoskeletons are compared. The constraint relationship and motion equations of instantaneous rotating center of the four-bar linkage knee joint are derived. Finally, gait simulations are performed on the two lower extremity exoskeleton models to obtain the position and angle information of the joints. The influence of the four-bar mechanism of bionic knee joint on the lower extremity exoskeleton is described. The simulation results show that the modified lower extremity exoskeleton not only improves the biomimetic performance of knee joint, but also conforms to the characteristics of human gait. © 2020 IEEE.

关键词： Kinematics

Automatic Segmentation Method for Cone-Beam Computed Tomography Image of the Bone Graft Region within Maxillary Sinus Based on the Atrous Spatial Pyramid Convolution Network

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Journal of Shanghai Jiaotong university(Science) 2021年第3期26卷 298-305页

作者： XU Jiangchang HE Shamin YU Dedong WU Yiqun CHEN Xiaojun Institute of Biomedical Manufacturing and Life Quality Engineering State Key Laboratory of Mechanical System and VibrationSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China Department of Second Dental Centre Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai200011China Institute of Medical Robotics Shanghai Jiao Tong UniversityShanghai200240China

Sinus floor elevation with a lateral window approach requires bone graft(BG)to ensure sufficient bone mass,and it is necessary to measure and analyse the BG region for follow-up of postoperative ***,the BG region from cone-beam computed tomography(CBCT)images is connected to the margin of the maxillary sinus,and its boundary is *** segmentation methods are usually performed manually by experienced doctors,and are complicated by challenges such as low efficiency and low *** this study,an auto-segmentation approach was applied to the BG region within the maxillary sinus based on an atrous spatial pyramid convolution(ASPC)*** ASPC module was adopted using residual connections to compose multiple atrous convolutions,which could extract more features on multiple ***,a segmentation network of the BG region with multiple ASPC modules was established,which effectively improved the segmentation *** the training data were insufficient,our networks still achieved good auto-segmentation results,with a dice coefficient(Dice)of 87.13%,an Intersection over Union(Iou)of 78.01%,and a sensitivity of 95.02%.Compared with other methods,our method achieved a better segmentation effect,and effectively reduced the misjudgement of *** method can thus be used to implement automatic segmentation of the BG region and improve doctors’work efficiency,which is of great importance for developing preliminary studies on the measurement of postoperative BG within the maxillary sinus.

关键词： atrous spatial pyramid convolution(ASPC) bone graft(BG)region medical image segmentation residual connection

Improving Kinematic Flexibility and Walking Performance of a Six-legged Robot by Rationally Designing Leg Morphology

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Journal of Bionic Engineering 2019年第4期16卷 608-620页

作者： Jie Chen Zhongchao Liang Yanhe Zhu Jie Zhao School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This paper explores the design of leg morphology in a six-legged *** by nature,where animals have different leg morphology,we examined how the difference in leg morphology influences behaviors of the *** this end,a systematic search was conducted by scanning over the parameter space consisting of default angles of leg joints of the six-legged robot,with two main objectives:to maximize the kinematic flexibility and walking performance of the *** show that(1)to have a high kinematic flexibility with both the torso and swing legs,the femur segment should tilt downwards by 5°-10°and the tibia segment should be vertically downwards or with a slight inward tilt;(2)to achieve relatively energy-efficient and steady walking,the tibia segment should be approximately vertically downwards,with the femur segment tilting upwards to lower the torso *** results of this study suggest that behaviors of legged robots can be passively enhanced by careful mechanical design choices,thereby leading to more competent legged machines.

关键词： six-legged robot leg morphology kinematic flexibility walking performance

The consistent behavior of negative Poisson's ratio with interlayer interactions

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arXiv 2022年

作者： Wang, Yancong Yu, Linfeng Zhang, Fa Chen, Qiang Zhan, Yuqi Zheng, Xiong Wang, Huimin Qin, Zhenzhen Qin, Guangzhao State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University Changsha410082 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Hunan Key Laboratory for Micro-Nano Energy Materials & Device School of Physics and Optoelectronics Xiangtan University Hunan Xiangtan411105 China School of Physics and Microelectronics Zhengzhou University Zhengzhou450001 China

Negative Poisson's ratio (NPR) is of great interest due to the novel applications in lots of fields. Films are the most commonly used form in practical applications, which involves multiple layers. However, the effect of interlayer interactions on the NPR is still unclear. In this study, based on first principles calculations, we systematically investigate the effect of interlayer interactions on the NPR by comparably studying single-layer graphene, few-layer graphene, h-BN, and graphene-BN heterostructure. It is found that they almost have the same geometry-strain response. Consequently, the NPR in bilayer graphene, triple-layer graphene, and graphene-BN heterostructure are consistent with that in single-layer graphene and h-BN. The fundamental mechanism lies in that the response to strain of the orbital coupling are consistent under the effect of interlayer interactions. The deep understanding of the NPR with the effect of interlayer interactions as achieved in this study is beneficial for the future design and development of micro-/nanoscale electromechanical devices with novel functions based on nanostructures. © 2022, CC BY-NC-SA.

关键词： Graphene

Payload-agnostic decoupling and hybrid vibration isolation control for a maglev platform with redundant actuation

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arXiv 2020年

作者： Gong, Zhaopei Ding, Liang Li, Shaozhen Yue, Honghao Gao, Haibo Deng, Zongquan State Key Laboratory of Robotics and System Harbin Institute of Technology

Payload-specific vibration control may be suitable for a particular task but lacks generality and transferability required for adapting to the various payload. Self-decoupling and robust vibration control are the crucial problem to achieve payload-agnostic vibration control. However, there are problems still unsolved. In this article, we present a maglev vibration isolation platform (MVIP), which aims to attenuate vibration in payload-agnostic task under dynamic environment. Since efforts trying to suppress disturbance will encounter inevitable coupling problems, we analyzed the reasons resulting in it and proposed unique and effective solutions. To achieve payload-agnostic vibration control, we proposed a new control strategy, which is the main contribution of this article. It consists of self-construct radial basis function neural network inversion (SRBFNNI) decoupling scheme and hybrid adaptive feed-forward internal model control (HAFIMC). The former one enables the MVIP creating a self inverse model with little prior knowledge and achieving self-decoupling. For the unique structure of MVIP, the vibration control problem is stated and addressed by the proposed HAFIMC, which utilizes the adaptive part to deal with the periodical disturbance and the internal mode part to deal with the stability. Copyright © 2020, The Authors. All rights reserved.

关键词： Inverse problems