Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787344
Vojtěch Vonásek, Robert Pěnička
Motion planning of 3D solid objects leads to a search in a 6D configuration space. Sampling-based planners randomly sample the configuration space and store the collision-free samples into a graph (roadmap) that can be searched by standard graph-search methods. The well-known issue of the sampling-based planners is the narrow passage problem. Narrow passages are small collision-free regions in the configuration space that are, due to their low volume, difficult to cover by the random samples, which prevents the sampling-based planners to find a path leading through the passages. By decreasing the size of the object, the relative volume of the narrow passages is increased, which helps to cover them more densely. This allows the planner to find an approximate solution, i.e., a solution feasible for the smaller object. The approximate solution can be then used to iteratively guide the sampling in the configuration space, while increasing the size of the object, until a solution for the original object is found. In this paper, we propose a modification of the iterative guiding process. To avoid a situation where the part of the guiding path is too close to obstacles of the configuration space, we shift it away from the obstacles. This requires to estimate the surface of the obstacle region, which is achieved by detecting its boundary configurations during the sampling process. Experiments have shown that the proposed modification outperforms the simple guiding using approximate solutions, as well as other related state-of-the-art planners.
{"title":"Computation of Approximate Solutions for Guided Sampling-Based Motion Planning of 3D Objects","authors":"Vojtěch Vonásek, Robert Pěnička","doi":"10.1109/RoMoCo.2019.8787344","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787344","url":null,"abstract":"Motion planning of 3D solid objects leads to a search in a 6D configuration space. Sampling-based planners randomly sample the configuration space and store the collision-free samples into a graph (roadmap) that can be searched by standard graph-search methods. The well-known issue of the sampling-based planners is the narrow passage problem. Narrow passages are small collision-free regions in the configuration space that are, due to their low volume, difficult to cover by the random samples, which prevents the sampling-based planners to find a path leading through the passages. By decreasing the size of the object, the relative volume of the narrow passages is increased, which helps to cover them more densely. This allows the planner to find an approximate solution, i.e., a solution feasible for the smaller object. The approximate solution can be then used to iteratively guide the sampling in the configuration space, while increasing the size of the object, until a solution for the original object is found. In this paper, we propose a modification of the iterative guiding process. To avoid a situation where the part of the guiding path is too close to obstacles of the configuration space, we shift it away from the obstacles. This requires to estimate the surface of the obstacle region, which is achieved by detecting its boundary configurations during the sampling process. Experiments have shown that the proposed modification outperforms the simple guiding using approximate solutions, as well as other related state-of-the-art planners.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127852170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787363
R. Guyonneau, F. Mercier
IstiABot is a mobile robot made for education and research purposes. This robot aims to be modular, easy to modify and used by first year students as well as last year students and researchers. To achieve those requirements, the robot is built on the top of a CANBus Network. This paper presents the robot and the approach behind its building. It also presents an educational application of the platform (tuning a PID controller) and a research application (Simultaneous Localization And Mapping - SLAM - experimentations). Finally it concludes about this experience and introduce two other robots that were built based on the IstiABot. As it was wanted for the robot to be as free as possible, all the source code and 3D modeling are available.
IstiABot是一款用于教育和研究目的的移动机器人。这个机器人的目标是模块化，易于修改和一年级学生以及去年的学生和研究人员使用。为了实现这些要求，机器人建立在CANBus网络的顶部。本文介绍了机器人及其构建背后的方法。它还介绍了该平台的教育应用(调整PID控制器)和研究应用(同时定位和映射- SLAM -实验)。最后总结了这次的经验，并介绍了另外两个基于IstiABot构建的机器人。由于希望机器人尽可能自由，所有的源代码和3D建模都是可用的。
{"title":"IstiABot, an Open Source Mobile Robot for Education and Research","authors":"R. Guyonneau, F. Mercier","doi":"10.1109/RoMoCo.2019.8787363","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787363","url":null,"abstract":"IstiABot is a mobile robot made for education and research purposes. This robot aims to be modular, easy to modify and used by first year students as well as last year students and researchers. To achieve those requirements, the robot is built on the top of a CANBus Network. This paper presents the robot and the approach behind its building. It also presents an educational application of the platform (tuning a PID controller) and a research application (Simultaneous Localization And Mapping - SLAM - experimentations). Finally it concludes about this experience and introduce two other robots that were built based on the IstiABot. As it was wanted for the robot to be as free as possible, all the source code and 3D modeling are available.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126270962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787373
A. Andreev, O. Peregudova
This paper proposes a solution to the trajectory tracking control problem of a mobile robot with three omni-wheels on the base of a delayed output feedback. We consider a dynamical model of the robot wherein the platform's center of mass is displaced from its geometrical center. The omni-wheels of the robot are independently driven by three DC motors. Based on the Lyapunov functional method a nonlinear bounded controller is constructed without measuring the velocities that solves the global trajectory tracking problem for the robot using only time-delayed position errors. Using the proposed approach, we construct also a sampled-data controller that ensures the uniform asymptotic stability of the reference trajectory.
{"title":"On Time-Delayed Feedback Trajectory Tracking Control of a Mobile Robot with Omni-Wheels","authors":"A. Andreev, O. Peregudova","doi":"10.1109/RoMoCo.2019.8787373","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787373","url":null,"abstract":"This paper proposes a solution to the trajectory tracking control problem of a mobile robot with three omni-wheels on the base of a delayed output feedback. We consider a dynamical model of the robot wherein the platform's center of mass is displaced from its geometrical center. The omni-wheels of the robot are independently driven by three DC motors. Based on the Lyapunov functional method a nonlinear bounded controller is constructed without measuring the velocities that solves the global trajectory tracking problem for the robot using only time-delayed position errors. Using the proposed approach, we construct also a sampled-data controller that ensures the uniform asymptotic stability of the reference trajectory.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"2675 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126459278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787341
K. Majek, J. Będkowski, M. Pelka, Jakub Ratajczak, A. Maslowski
This paper describes the approach to three European robotic competitions ERL 2017 Major Tournament, ERL 2018 Local Tournament and ELROB 2018. In all of the competitions, GPU enabled SLAM was used to deliver the 3D map of the environment during the mission. In both ERL competitions, deep neural networks were used to identify objects of potential interest. Datasets used to train models and architectures of neural networks are described. All of the object detection models used during the competitions are published in a publicly available repository11https://github.com/karolmajek/ERL2017-ERL2018-Emergency-Object-Detection.
本文介绍了三场欧洲机器人比赛ERL 2017 Major Tournament、ERL 2018 Local Tournament和ELROB 2018的方法。在所有的比赛中，GPU支持的SLAM被用于在任务期间提供环境的3D地图。在两个ERL竞赛中，深度神经网络被用来识别潜在的兴趣对象。描述了用于训练模型和神经网络架构的数据集。竞赛期间使用的所有目标检测模型都发布在一个公开可用的存储库中11https://github.com/karolmajek/ERL2017-ERL2018-Emergency-Object-Detection。
{"title":"Object Detection and Mapping During European Robotic Competitions - Lesson Learned","authors":"K. Majek, J. Będkowski, M. Pelka, Jakub Ratajczak, A. Maslowski","doi":"10.1109/RoMoCo.2019.8787341","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787341","url":null,"abstract":"This paper describes the approach to three European robotic competitions ERL 2017 Major Tournament, ERL 2018 Local Tournament and ELROB 2018. In all of the competitions, GPU enabled SLAM was used to deliver the 3D map of the environment during the mission. In both ERL competitions, deep neural networks were used to identify objects of potential interest. Datasets used to train models and architectures of neural networks are described. All of the object detection models used during the competitions are published in a publicly available repository11https://github.com/karolmajek/ERL2017-ERL2018-Emergency-Object-Detection.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116058290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787378
J. Bae, Jaekyu An, Goobong Chung
The non-destructive inspection using magnetic leakage method is suitable for inspection of the pipe having high magnetic permeability. In this paper, we introduce the development and experimental analysis of a robot that performs non-destructive precision inspection of structural condition inside the water supply pipe. The operation algorithm of the robots is proposed to consider simulation environment, modeling, contact mechanics, and friction force along the water pipe. Multi-body dynamics experimental analysis was conducted based on the simplified kinematic model. Numerical simulation and experimental analysis have been performed to verify the proposed operation method of the robot in the pipe. As a result, structural defect in the water pipe was detected using the defect analysis algorithm based on the sensor signal measured by the proposed inspection robot.
{"title":"Multi-body Dynamics Experimental Analysis for Non-Destructive Inspection Robot in Water Main Pipe","authors":"J. Bae, Jaekyu An, Goobong Chung","doi":"10.1109/RoMoCo.2019.8787378","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787378","url":null,"abstract":"The non-destructive inspection using magnetic leakage method is suitable for inspection of the pipe having high magnetic permeability. In this paper, we introduce the development and experimental analysis of a robot that performs non-destructive precision inspection of structural condition inside the water supply pipe. The operation algorithm of the robots is proposed to consider simulation environment, modeling, contact mechanics, and friction force along the water pipe. Multi-body dynamics experimental analysis was conducted based on the simplified kinematic model. Numerical simulation and experimental analysis have been performed to verify the proposed operation method of the robot in the pipe. As a result, structural defect in the water pipe was detected using the defect analysis algorithm based on the sensor signal measured by the proposed inspection robot.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124727228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787366
S. Mirghasemi, D. Necsulescu, J. Sasiadek
Although concept of fractional calculus was known for centuries, it was not considered in engineering due to the satisfactory performance of integer order models and control. However, recently, engineers and researchers started to investigate the potentially high performance of fractional calculus in various fields including control theory. This article analyzes the relative performance of fractional versus integer order PID for the quadcopter. After introducing fractional calculus and the mathematical tools which have been used, the dynamics of the quadcopter is presented with additional consideration of the ground effect and torque saturation and sensor measurement. The performance of fractional order controller is evaluated by comparing it to an integer order controller.
{"title":"Quadcopter Fractional Controller Accounting for Ground Effect","authors":"S. Mirghasemi, D. Necsulescu, J. Sasiadek","doi":"10.1109/RoMoCo.2019.8787366","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787366","url":null,"abstract":"Although concept of fractional calculus was known for centuries, it was not considered in engineering due to the satisfactory performance of integer order models and control. However, recently, engineers and researchers started to investigate the potentially high performance of fractional calculus in various fields including control theory. This article analyzes the relative performance of fractional versus integer order PID for the quadcopter. After introducing fractional calculus and the mathematical tools which have been used, the dynamics of the quadcopter is presented with additional consideration of the ground effect and torque saturation and sensor measurement. The performance of fractional order controller is evaluated by comparing it to an integer order controller.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128836186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787355
Lukasz Mucha, Krzysztof Lis, Dariusz Krawczyk
In article, the design stages, principle of operation and static tests of the force that is exerted on the operator by the RobinHand motion controller were presented. Besides that, details of such issues as, the developed laboratory stand for testing the force interactions, all concepts and ways of implementing the transfer of tactile stimuli from real devices or virtual reality to the user/surgeon, subsequent variants of the developed devices with the short description of them, the project of the operator-surgeon stand that is based on the assumption that the method of control of this device is compatible with the natural work of the surgeon as well as the project of control console that is used to manipulate the surgical robot were presented.
{"title":"Experimental Verification of Force Interactions for Robinhand Prototype Motion Controller","authors":"Lukasz Mucha, Krzysztof Lis, Dariusz Krawczyk","doi":"10.1109/RoMoCo.2019.8787355","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787355","url":null,"abstract":"In article, the design stages, principle of operation and static tests of the force that is exerted on the operator by the RobinHand motion controller were presented. Besides that, details of such issues as, the developed laboratory stand for testing the force interactions, all concepts and ways of implementing the transfer of tactile stimuli from real devices or virtual reality to the user/surgeon, subsequent variants of the developed devices with the short description of them, the project of the operator-surgeon stand that is based on the assumption that the method of control of this device is compatible with the natural work of the surgeon as well as the project of control console that is used to manipulate the surgical robot were presented.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131292632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787343
Nadhir Mansour Ben Lakhal, L. Adouane, Othman Nasri, J. Slama
The transportation systems reliability is addressed in this work. A comprehensive comparison between the probabilistic and the interval-based uncertainty handling approaches for autonomous navigation has been detailed. Based on this comparative study, a set-membership safety verification technique that monitors the correlation between variables has been proposed to achieve an optimal uncertainty assessment. Further, a Principle Component Analysis (PCA) diagnosis process has been extended to handle interval-data. Finally, a strong link between the proposed automotive diagnosis and risk management has been constructed to ensure a high robustness to uncertainty. The proposed interval-based solutions have been integrated on an Adaptive Cruise Control (ACC) system. Simulation results prove the proposed diagnosis and risk management efficiency in handling uncertainties and faults.
{"title":"Interval-based Solutions for Reliable and Safe Navigation of Intelligent Autonomous Vehicles","authors":"Nadhir Mansour Ben Lakhal, L. Adouane, Othman Nasri, J. Slama","doi":"10.1109/RoMoCo.2019.8787343","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787343","url":null,"abstract":"The transportation systems reliability is addressed in this work. A comprehensive comparison between the probabilistic and the interval-based uncertainty handling approaches for autonomous navigation has been detailed. Based on this comparative study, a set-membership safety verification technique that monitors the correlation between variables has been proposed to achieve an optimal uncertainty assessment. Further, a Principle Component Analysis (PCA) diagnosis process has been extended to handle interval-data. Finally, a strong link between the proposed automotive diagnosis and risk management has been constructed to ensure a high robustness to uncertainty. The proposed interval-based solutions have been integrated on an Adaptive Cruise Control (ACC) system. Simulation results prove the proposed diagnosis and risk management efficiency in handling uncertainties and faults.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121108110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787347
P. Herman
The paper addresses the problem of underwater vehicle dynamic model evaluation based on a velocity tracking controller. The proposed strategy is composed of two steps: building of a velocity control algorithm in terms of the Nor-malized Generalized Velocity Components (NGVC), as a tool for the analysis, and its use for the dynamics investigation of the vehicle. The algorithm is expressed in terms of the transformed equations of motion arising from the inertia matrix decomposition. Consequently, it contains the system dynamics in the control gain matrices. This feature causes that not only the error convergence can be achieved (strictly related to the vehicle dynamics) but also some information about the system model is available. The method is suitable for fully actuated underwater vehicles and it can serve for numerical tests of the assumed model before a real experiment. The effectiveness of the proposed strategy, i.e. application of the controller for dynamics analysis, is shown via simulation on a 6 DOF underwater vehicle.
{"title":"Numerical Test of Underwater Vehicle Dynamics Using Velocity Controller","authors":"P. Herman","doi":"10.1109/RoMoCo.2019.8787347","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787347","url":null,"abstract":"The paper addresses the problem of underwater vehicle dynamic model evaluation based on a velocity tracking controller. The proposed strategy is composed of two steps: building of a velocity control algorithm in terms of the Nor-malized Generalized Velocity Components (NGVC), as a tool for the analysis, and its use for the dynamics investigation of the vehicle. The algorithm is expressed in terms of the transformed equations of motion arising from the inertia matrix decomposition. Consequently, it contains the system dynamics in the control gain matrices. This feature causes that not only the error convergence can be achieved (strictly related to the vehicle dynamics) but also some information about the system model is available. The method is suitable for fully actuated underwater vehicles and it can serve for numerical tests of the assumed model before a real experiment. The effectiveness of the proposed strategy, i.e. application of the controller for dynamics analysis, is shown via simulation on a 6 DOF underwater vehicle.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115595534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/RoMoCo.2019.8787375
M. Cholewinski, A. Mazur
Following paper present a description of a non-holonomic mobile manipulator relative to three-dimensional path. Path has been orthogonally parametrized to the Serret-Frenet frame moving along the curve. Control law for the RTR manipulator with fixed first joint, mounted on the unicycle platform, which realizes the path following has been presented. Mathematical solutions has been justified in simulation results.
{"title":"Path Tracking by the Nonholonomic Mobile Manipulator","authors":"M. Cholewinski, A. Mazur","doi":"10.1109/RoMoCo.2019.8787375","DOIUrl":"https://doi.org/10.1109/RoMoCo.2019.8787375","url":null,"abstract":"Following paper present a description of a non-holonomic mobile manipulator relative to three-dimensional path. Path has been orthogonally parametrized to the Serret-Frenet frame moving along the curve. Control law for the RTR manipulator with fixed first joint, mounted on the unicycle platform, which realizes the path following has been presented. Mathematical solutions has been justified in simulation results.","PeriodicalId":415070,"journal":{"name":"2019 12th International Workshop on Robot Motion and Control (RoMoCo)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125895531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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