Industrial Robot-The International Journal of Robotics Research and Application最新文献

{"title":"Human-robot force cooperation analysis by deep reinforcement learning","authors":"Shaodong Li, Xiao-hua Yuan, Hongjian Yu","doi":"10.1108/ir-05-2022-0135","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0135","url":null,"abstract":"\u0000Purpose\u0000This study aims to realize natural and effort-saving motion behavior and improve effectiveness for different operators in human–robot force cooperation.\u0000\u0000\u0000Design/methodology/approach\u0000The parameter of admittance model is identified by deep deterministic policy gradient (DDPG) to realize human–robot force cooperation for different operators in this paper. The movement coupling problem of hybrid robot is solved by realizing position and pose drags. In DDPG, minimum jerk trajectory is selected as the reward objective function, and the variable prioritized experience replay is applied to balance the exploration and exploitation.\u0000\u0000\u0000Findings\u0000A series of simulations are implemented to validate the superiority and stability of DDPG. Furthermore, three sets of experiments involving mass parameter, damping parameter and DDPG are implemented, the effect of DDPG in real environment is validated and could meet the cooperation demand for different operators.\u0000\u0000\u0000Originality/value\u0000DDPG is applied in admittance model identification to realize human–robot force cooperation for different operators. And minimum jerk trajectory is introduced into reward objective to meet requirement of human arm free movements. The algorithm proposed in this paper could be further extended in the other operation task.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"42 1","pages":"287-298"},"PeriodicalIF":1.8,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82667980","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}

{"title":"A robotic 3D printing system for supporting-free manufacturing of complex model based on FDM technology","authors":"Xishuang Jing, Duanping Lv, F. Xie, C. Zhang, Siyu Chen, Ben Mou","doi":"10.1108/ir-05-2022-0136","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0136","url":null,"abstract":"\u0000Purpose\u00003D printing technology has the characteristics of fast forming and low cost and can manufacture parts with complex structures. At present, it has been widely used in various manufacturing fields. However, traditional 3-axis printing has limitations of the support structure and step effect due to its low degree of freedom. The purpose of this paper is to propose a robotic 3D printing system that can realize support-free printing of parts with complex structures.\u0000\u0000\u0000Design/methodology/approach\u0000A robotic 3D printing system consisting of a 6-degrees of freedom robotic manipulator with a material extrusion system is proposed for multi-axis additive manufacturing applications. And the authors propose an approximation method for the extrusion value E based on the accumulated arc length of the already printed points, which is used to realize the synchronous movement between multiple systems. Compared with the traditional 3-axis printing system, the proposed robotic 3D printing system can provide greater flexibility when printing complex structures and even realize curved layer printing.\u0000\u0000\u0000Findings\u0000Two printing experiments show that compared with traditional 3D printing, a multi-axis 3D printing system saves 47% and 79% of materials, respectively, and the mechanical properties of curved layer printing using a multi-axis 3D printing system are also better than that of 3-axis printing.\u0000\u0000\u0000Originality/value\u0000This paper shows a simple and effective method to realize the synchronous movement between multiple systems so as to develop a robotic 3D printing system that can realize support-free printing and verifies the feasibility of the system through experiments.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"104 1","pages":"314-325"},"PeriodicalIF":1.8,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73032785","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}

{"title":"Robot vision-based control strategy to suppress residual vibration of a flexible beam for assembly","authors":"Chetan Jalendra, B. K. Rout, Amol Marathe","doi":"10.1108/ir-07-2022-0169","DOIUrl":"https://doi.org/10.1108/ir-07-2022-0169","url":null,"abstract":"\u0000Purpose\u0000Industrial robots are extensively used in the robotic assembly of rigid objects, whereas the assembly of flexible objects using the same robot becomes cumbersome and challenging due to transient disturbance. The transient disturbance causes vibration in the flexible object during robotic manipulation and assembly. This is an important problem as the quick suppression of undesired vibrations reduces the cycle time and increases the efficiency of the assembly process. Thus, this study aims to propose a contactless robot vision-based real-time active vibration suppression approach to handle such a scenario.\u0000\u0000\u0000Design/methodology/approach\u0000A robot-assisted camera calibration method is developed to determine the extrinsic camera parameters with respect to the robot position. Thereafter, an innovative robot vision method is proposed to identify a flexible beam grasped by the robot gripper using a virtual marker and obtain the dimension, tip deflection as well as velocity of the same. To model the dynamic behaviour of the flexible beam, finite element method (FEM) is used. The measured dimensions, tip deflection and velocity of a flexible beam are fed to the FEM model to predict the maximum deflection. The difference between the maximum deflection and static deflection of the beam is used to compute the maximum error. Subsequently, the maximum error is used in the proposed predictive maximum error-based second-stage controller to send the control signal for vibration suppression. The control signal in form of trajectory is communicated to the industrial robot controller that accommodates various types of delays present in the system.\u0000\u0000\u0000Findings\u0000The effectiveness and robustness of the proposed controller have been validated using simulation and experimental implementation on an Asea Brown Boveri make IRB 1410 industrial robot with a standard low frame rate camera sensor. In this experiment, two metallic flexible beams of different dimensions with the same material properties have been considered. The robot vision method measures the dimension within an acceptable error limit i.e. ±3%. The controller can suppress vibration amplitude up to approximately 97% in an average time of 4.2 s and reduces the stability time up to approximately 93% while comparing with control and without control suppression time. The vibration suppression performance is also compared with the results of classical control method and some recent results available in literature.\u0000\u0000\u0000Originality/value\u0000The important contributions of the current work are the following: an innovative robot-assisted camera calibration method is proposed to determine the extrinsic camera parameters that eliminate the need for any reference such as a checkerboard, robotic assembly, vibration suppression, second-stage controller, camera calibration, flexible beam and robot vision; an approach for robot vision method is developed to identify the object using a virtual marker and measure its dimension gras","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"154 1","pages":"401-420"},"PeriodicalIF":1.8,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75325256","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}

{"title":"The first half century of industrial robot: 50 years of robotic developments","authors":"R. Bogue","doi":"10.1108/ir-10-2022-0251","DOIUrl":"https://doi.org/10.1108/ir-10-2022-0251","url":null,"abstract":"\u0000Purpose\u0000This paper aims to trace the technological and commercial developments in robotics over the last 50 years, from 1973, the year in which this journal was founded, to the present day.\u0000\u0000\u0000Design/methodology/approach\u0000Following an introduction, this identifies key robot developments on a decade-by-decade basis and considers research, products, applications and corporate activity and also highlights many of the enabling technologies. Brief conclusions are draw.\u0000\u0000\u0000Findings\u0000The robot industry has changed beyond all recognition during the last half century. Enabled by developments in microelectronics, computing, sensors, imaging technologies, data communication and power sources, today robots satisfy a multitude of applications and play a role in almost every sphere of human activity.\u0000\u0000\u0000Originality/value\u0000This provides a detailed review of robotic developments during the last 50 years.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"15 5, Suppl. 1","pages":"1-10"},"PeriodicalIF":1.8,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83023570","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}

{"title":"Kinematic modeling of a spatial three degrees-of-freedom compliant micro-motion parallel mechanism considering input coupling effect and bilateral restrained torsion","authors":"Zhicheng Song, Xiang Li, Xiaolong Yang, Yao Li, Linkang Wang, Hongtao Wu","doi":"10.1108/ir-06-2022-0146","DOIUrl":"https://doi.org/10.1108/ir-06-2022-0146","url":null,"abstract":"\u0000Purpose\u0000This paper aims to improve the kinematic modeling accuracy of a spatial three-degrees-of-freedom compliant micro-motion parallel mechanism by proposing a modified modeling method based on the structural matrix method (SMM).\u0000\u0000\u0000Design/methodology/approach\u0000This paper analyzes the problem that the torsional compliance equation of the circular notched hinge is no longer applicable because it is subject to bilateral restrained torsion. The torsional compliance equation is modified by introducing the relative length coefficient. The input coupling effect, which is often neglected, is considered in kinematic modeling. The symbolic expression of the input coupling matrix is obtained. Theory, simulation and experimentation are presented to show the validity of the proposed kinematic model.\u0000\u0000\u0000Findings\u0000The results show that the proposed kinematics model can improve the modeling accuracy by comparing the theoretical, finite element method (FEM) and experimental method.\u0000\u0000\u0000Originality/value\u0000This work provides a feasible scheme for CMPM kinematics modeling. It can be better applied to the optimization design based on the kinematic model in the future.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"134 1","pages":"385-400"},"PeriodicalIF":1.8,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77367703","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}

{"title":"A robotic polishing trajectory planning method for TBCs of aero-engine turbine blade using measured point cloud","authors":"Xufeng Liang, Zhenhua Cai, Chunnian Zeng, Zixin Mu, Zifan Li, Fan Yang, Tingyang Chen, S. Dong, Chunming Deng, S. Niu","doi":"10.1108/ir-05-2022-0141","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0141","url":null,"abstract":"\u0000Purpose\u0000The application of thermal barrier coatings (TBCs) allows aero-engine blades to operate at higher temperatures with higher efficiency. The preparation of the TBCs increases the surface roughness of the blade, which impacts the thermal cycle life and thermal insulation performance of the coating. To reduce the surface roughness of blades, particularly the blades with small size and complex curvature, this paper aims to propose a method for industrial robot polishing trajectory planning based on on-site measuring point cloud.\u0000\u0000\u0000Design/methodology/approach\u0000The authors propose an integrated robotic polishing trajectory planning method using point cloud processing technical. At first, the acquired point cloud is preprocessed, which includes filtering and plane segmentation algorithm, to extract the blade body point cloud. Then, the point cloud slicing algorithm and the intersection method are used to create a preliminary contact point set. Finally, the Douglas–Peucker algorithm and pose frame estimation are applied to extract the tool-tip positions and optimize the tool contact posture, respectively. The resultant trajectory is evaluated by simulation and experiment implementation.\u0000\u0000\u0000Findings\u0000The target points of trajectory are not evenly distributed on the blade surface but rather fluctuate with surface curvature. The simulated linear and orientation speeds of the robot end could be relatively steady over 98% of the total time within 20% reduction of the rest time. After polishing experiments, the coating roughness on the blade surface is reduced dramatically from Ra 7–8 µm to below Ra 1.0 µm. The removal of the TBCs is less than 100 mg, which is significantly less than the weight of the prepared coatings. The blade surface becomes smoothed to a mirror-like state.\u0000\u0000\u0000Originality/value\u0000The research on robotic polishing of aero-engine turbine blade TBCs is worthwhile. The real-time trajectory planning based on measuring point cloud can address the problem that there is no standard computer-aided drawing model and the geometry and size of the workpiece to be processed differ. The extraction and optimization of tool contact points based on point cloud features can enhance the smoothness of the robot movement, stability of the polishing speed and performance of the blade surface after polishing.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"32 23 1","pages":"275-286"},"PeriodicalIF":1.8,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82828310","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}

{"title":"A human augmentation device design review: supernumerary robotic limbs","authors":"Ziyu Liao, Bai Chen, Tianzuo Chang, Qianjian Zheng, Keming Liu, Junnan Lv","doi":"10.1108/ir-03-2022-0079","DOIUrl":"https://doi.org/10.1108/ir-03-2022-0079","url":null,"abstract":"\u0000Purpose\u0000Supernumerary robotic limbs (SRLs) are a new type of wearable robot, which improve the user’s operating and perceive the user’s environment by extra robotic limbs. There are some literature reviews about the SRLs’ key technology and development trend, but the design of SRLs has not been fully discussed and summarized. This paper aims to focus on the design of SRLs and provides a comprehensive review of the ontological structure design of SRLs.\u0000\u0000\u0000Design/methodology/approach\u0000In this paper, the related literature of SRLs is summarized and analyzed by VOSviewer. The structural features of different types of SRLs are extracted, and then discuss the design approach and characteristics of SRLs which are different from typical wearable robots.\u0000\u0000\u0000Findings\u0000The design concept of SRLs is different from the conventional wearable robots. SRLs have various reconfiguration and installed positions, and it will influence the safety and cooperativeness performance of SRLs.\u0000\u0000\u0000Originality/value\u0000This paper focuses on discussing the structural design of SRLs by literature review, and this review will help researchers understand the structural features of SRLs and key points of the ontological design of SRLs, which can be used as a reference for designing SRLs.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"14 1","pages":"256-274"},"PeriodicalIF":1.8,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82643393","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}

{"title":"A hierarchical visual model for robot automatic arc welding guidance","authors":"Chen Chen, Tingyang Chen, Zhenhua Cai, Chunnian Zeng, Xiaoyue Jin","doi":"10.1108/ir-05-2022-0127","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0127","url":null,"abstract":"\u0000Purpose\u0000The traditional vision system cannot automatically adjust the feature point extraction method according to the type of welding seam. In addition, the robot cannot self-correct the laying position error or machining error. To solve this problem, this paper aims to propose a hierarchical visual model to achieve automatic arc welding guidance.\u0000\u0000\u0000Design/methodology/approach\u0000The hierarchical visual model proposed in this paper is divided into two layers: welding seam classification layer and feature point extraction layer. In the welding seam classification layer, the SegNet network model is trained to identify the welding seam type, and the prediction mask is obtained to segment the corresponding point clouds. In the feature point extraction layer, the scanning path is determined by the point cloud obtained from the upper layer to correct laying position error. The feature points extraction method is automatically determined to correct machining error based on the type of welding seam. Furthermore, the corresponding specific method to extract the feature points for each type of welding seam is proposed. The proposed visual model is experimentally validated, and the feature points extraction results as well as seam tracking error are finally analyzed.\u0000\u0000\u0000Findings\u0000The experimental results show that the algorithm can well accomplish welding seam classification, feature points extraction and seam tracking with high precision. The prediction mask accuracy is above 90% for three types of welding seam. The proposed feature points extraction method for each type of welding seam can achieve sub-pixel feature extraction. For the three types of welding seam, the maximum seam tracking error is 0.33–0.41 mm, and the average seam tracking error is 0.11–0.22 mm.\u0000\u0000\u0000Originality/value\u0000The main innovation of this paper is that a hierarchical visual model for robotic arc welding is proposed, which is suitable for various types of welding seam. The proposed visual model well achieves welding seam classification, feature point extraction and error correction, which improves the automation level of robot welding.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"8 1","pages":"299-313"},"PeriodicalIF":1.8,"publicationDate":"2022-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83071115","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}

{"title":"Robotic direct grinding for unknown workpiece contour based on adaptive constant force control and human-robot collaboration","authors":"Wei Zhao, Juliang Xiao, Sijiang Liu, Saixiong Dou, Haitao Liu","doi":"10.1108/ir-01-2022-0021","DOIUrl":"https://doi.org/10.1108/ir-01-2022-0021","url":null,"abstract":"\u0000Purpose\u0000In customized production such as plate workpiece grinding, because of the diversity of the workpiece shapes and the positional/orientational clamping errors, great efforts are taken to repeatedly calibrate and program the robots. To change this situation, the purpose of this study is to propose a method of robotic direct grinding for unknown workpiece contour based on adaptive constant force control and human–robot collaboration.\u0000\u0000\u0000Design/methodology/approach\u0000First, an adaptive constant force controller based on stiffness estimation is proposed, which can distinguish the contact of the human hand and the unknown workpiece contour. Second, a normal vector search algorithm is developed to calculate the normal vector of the unknown workpiece contour in real-time. Finally, the force and position are controlled in the calculated normal and tangential directions to realize the direct grinding.\u0000\u0000\u0000Findings\u0000The method considers the disturbance of the tangential grinding force and the friction, so the robot can track and grind the workpiece contour simultaneously. The experiments prove that the method can ensure the force error and the normal vector calculating error within 0.3 N and 4°. This human–robot collaboration pattern improves the convenience of the grinding process.\u0000\u0000\u0000Research limitations/implications\u0000The proposed method realizes constant force grinding of unknown workpiece contour in real-time and ensures the grinding consistency. In addition, combined with human–robot collaboration, the method saves the time spent in repeated calibration and programming.\u0000\u0000\u0000Originality/value\u0000Compared with other related research, this method has better accuracy and anti-disturbance capability of force control and normal vector calculation during the actual grinding process.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"130 1","pages":"376-384"},"PeriodicalIF":1.8,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76663066","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}

{"title":"Human-robot kinematics mapping method based on dynamic equivalent points","authors":"Jing Zhao, Xin Wang, Biyun Xie, Ziqiang Zhang","doi":"10.1108/ir-02-2022-0056","DOIUrl":"https://doi.org/10.1108/ir-02-2022-0056","url":null,"abstract":"\u0000Purpose\u0000This paper aims to present a new kinematics mapping method based on dynamic equivalent points. In teleoperation, this method enables a robotic (follower) arm to mimic human (leader) arm postures and avoid obstacles in a human-like manner.\u0000\u0000\u0000Design/methodology/approach\u0000The information of the human arm is extracted based on the characteristics of human arm motion, and the concept of equivalent points is introduced. Then, an equivalent point is determined to transform the robotic arm with a nonhuman-like kinematic structure into an anthropomorphic robotic arm. Based on this equivalent point, a mapping method is developed to ensure that the two arms are similar. Finally, the similarity between the human elbow angle and robot elbow angle is further improved by using this method and an augmented Jacobian matrix with a compensation coefficient.\u0000\u0000\u0000Findings\u0000Numerical simulations and physical prototype experiments are conducted to verify the effectiveness and feasibility of the proposed method. In environments with obstacles, this method can adjust the position of the equivalent point in real time to avoid obstacles. In environments without obstacles, the similarity between the human elbow angle and robot elbow angle is further improved at the expense of the end-effector accuracy.\u0000\u0000\u0000Originality/value\u0000This study presents a new kinematics mapping method, which can realize the complete mapping between the human arm and heterogeneous robotic arm in teleoperation. This method is versatile and can be applied to various mechanical arms with different structures.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"2 1","pages":"219-233"},"PeriodicalIF":1.8,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91203366","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}