Pub Date : 2011-06-20DOI: 10.1109/MED.2011.5983158
M. Caccia, M. Bibuli, G. Bruzzone, V. Djapic, S. Fioravanti, A. Grati
This article describes the collaborative effort between NURC and CNR-ISSIA to increase the functional autonomy of Unmanned Surface Vehicles. The assets used for this demonstration were the CNR-ISSIA Charlie catamaran-type USV with its autonomy software, and NURC's payload module consisting of a sonar, pan-tilt unit, and the control software for both. The goal was to interface the two separate autonomy modules in order to maneuver the USV relative to an interesting target (demonstrated with a bottom target). Charlie's mission is to carry the payload while performing various behaviors to survey an area of interest. Whenever an interesting potential target is seen in the view of the forward looking sonar, the payload control software takes over control from Charlie's main vehicle computer, interrupts its pre-programmed behavior, and sends the necessary messages so the USV adapts its track based on the target location. The demonstration took place in Murter, Croatia during the 2010 Breaking the Surface Symposium.
{"title":"Modular USV and payload design for advanced capabilities in marine security applications","authors":"M. Caccia, M. Bibuli, G. Bruzzone, V. Djapic, S. Fioravanti, A. Grati","doi":"10.1109/MED.2011.5983158","DOIUrl":"https://doi.org/10.1109/MED.2011.5983158","url":null,"abstract":"This article describes the collaborative effort between NURC and CNR-ISSIA to increase the functional autonomy of Unmanned Surface Vehicles. The assets used for this demonstration were the CNR-ISSIA Charlie catamaran-type USV with its autonomy software, and NURC's payload module consisting of a sonar, pan-tilt unit, and the control software for both. The goal was to interface the two separate autonomy modules in order to maneuver the USV relative to an interesting target (demonstrated with a bottom target). Charlie's mission is to carry the payload while performing various behaviors to survey an area of interest. Whenever an interesting potential target is seen in the view of the forward looking sonar, the payload control software takes over control from Charlie's main vehicle computer, interrupts its pre-programmed behavior, and sends the necessary messages so the USV adapts its track based on the target location. The demonstration took place in Murter, Croatia during the 2010 Breaking the Surface Symposium.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126864125","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 : 2011-06-20DOI: 10.1109/MED.2011.5983179
F. Altaf, José Araújo, Aitor Hernandez, H. Sandberg, K. Johansson
This paper studies the design and real-time implementation of an event-triggered controller for a nonlinear 3D tower crane where the communication between the controller and the actuators is performed over a low-power wireless network. A flexible Event-Generation Circuit (EGC) is proposed in order to implement event-driven controllers for Networked Control Systems. Furthermore, a detailed experimental analysis on the performance of the event-triggered controller and the influence of packet losses on the transmitted actuation messages are presented. The results show that the event-triggered controllers in networked control systems are able to maintain the same level of performance as compared to periodic controllers, while increasing the sensors/actuators lifetime by reducing network bandwidth utilization.
{"title":"Wireless event-triggered controller for a 3D tower crane lab process","authors":"F. Altaf, José Araújo, Aitor Hernandez, H. Sandberg, K. Johansson","doi":"10.1109/MED.2011.5983179","DOIUrl":"https://doi.org/10.1109/MED.2011.5983179","url":null,"abstract":"This paper studies the design and real-time implementation of an event-triggered controller for a nonlinear 3D tower crane where the communication between the controller and the actuators is performed over a low-power wireless network. A flexible Event-Generation Circuit (EGC) is proposed in order to implement event-driven controllers for Networked Control Systems. Furthermore, a detailed experimental analysis on the performance of the event-triggered controller and the influence of packet losses on the transmitted actuation messages are presented. The results show that the event-triggered controllers in networked control systems are able to maintain the same level of performance as compared to periodic controllers, while increasing the sensors/actuators lifetime by reducing network bandwidth utilization.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127021939","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 : 2011-06-20DOI: 10.1109/MED.2011.5983006
E. Kamal, A. Aitouche, M. Bayart
This paper presents the novel Fuzzy Fault Tolerant Control (FFTC) of Wind Energy Conversion System (WECS) subject to actuator faults. The proposed algorithm combines the merits of: (i) The states of the closed-loop system will follow those of a user-defined stable reference model despite the presence of actuator faults; (ii) Maximizes the power coefficient for a fixed pitch variable speed wind turbines. The Takagi-Sugeno (TS) fuzzy model system with actuator faults is adopted for modelling the nonlinear dynamics of the WECS and establishing fuzzy state observer. Sufficient conditions are derived for robust stabilization in the sense of Lyapunov asymptotic stability and are formulated in the format of Linear Matrix Inequalities (LMIs). The design technique is applied to a dynamic model of wind energy conversion system to illustrate the effectiveness of the proposed FFTC.
{"title":"A fuzzy approach for actuator fault-tolerant control of Wind Energy Conversion Systems","authors":"E. Kamal, A. Aitouche, M. Bayart","doi":"10.1109/MED.2011.5983006","DOIUrl":"https://doi.org/10.1109/MED.2011.5983006","url":null,"abstract":"This paper presents the novel Fuzzy Fault Tolerant Control (FFTC) of Wind Energy Conversion System (WECS) subject to actuator faults. The proposed algorithm combines the merits of: (i) The states of the closed-loop system will follow those of a user-defined stable reference model despite the presence of actuator faults; (ii) Maximizes the power coefficient for a fixed pitch variable speed wind turbines. The Takagi-Sugeno (TS) fuzzy model system with actuator faults is adopted for modelling the nonlinear dynamics of the WECS and establishing fuzzy state observer. Sufficient conditions are derived for robust stabilization in the sense of Lyapunov asymptotic stability and are formulated in the format of Linear Matrix Inequalities (LMIs). The design technique is applied to a dynamic model of wind energy conversion system to illustrate the effectiveness of the proposed FFTC.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127882057","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 : 2011-06-20DOI: 10.1109/MED.2011.5983225
Petros Giataganas, N. Evangeliou, Y. Koveos, Eleni Kelasidi, A. Tzes
The development and experimental evaluation of a prototype endoscopic robotic surgical tool is presented in this article. Smart memory alloys (SMA) are used as wires in a tendon-driven actuation mechanism. The 2N-DOF redundant manipulator is a cascade configuration of N-universal joint modules. The kinematics of the tool is analyzed and simple yet effective controllers relying on a constrained non-linear optimization problem are offered. The surgical tool's shape can be deformed according to a predefined profile leading to more versatile configurations than the existing designs. The efficiency of the overall system is investigated in experimental studies where its performance is evaluated by a customized 3D-video system.
{"title":"Design and experimental evaluation of an innovative SMA-based tendon-driven redundant endoscopic robotic surgical tool","authors":"Petros Giataganas, N. Evangeliou, Y. Koveos, Eleni Kelasidi, A. Tzes","doi":"10.1109/MED.2011.5983225","DOIUrl":"https://doi.org/10.1109/MED.2011.5983225","url":null,"abstract":"The development and experimental evaluation of a prototype endoscopic robotic surgical tool is presented in this article. Smart memory alloys (SMA) are used as wires in a tendon-driven actuation mechanism. The 2N-DOF redundant manipulator is a cascade configuration of N-universal joint modules. The kinematics of the tool is analyzed and simple yet effective controllers relying on a constrained non-linear optimization problem are offered. The surgical tool's shape can be deformed according to a predefined profile leading to more versatile configurations than the existing designs. The efficiency of the overall system is investigated in experimental studies where its performance is evaluated by a customized 3D-video system.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132845205","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 : 2011-06-20DOI: 10.1109/MED.2011.5983147
E. Kosmatopoulos, S. Baldi, K. Aboudolas, D. Rovas, A. Papachristodoulou, P. Ioannou
Based on recent advances on convex design for Large-Scale Control Systems (LSCSs) and robust and efficient LSCS self-tuning/adaptation, a methodology is proposed in this paper which aims at providing an integrated LSCS-design, applicable to large-scale systems of arbitrary scale, heterogeneity and complexity and capable of: 1) Providing stable, efficient and arbitrarily-close-to-optimal LSCS performance; 2) Being able to incorporate a variety of constraints, including limited control constraints as well as constraints that are nonlinear functions of the system controls and outputs (sensor measurements); 3) Being intrinsically self-tunable, able to rapidly and efficiently optimize LSCS performance when short-, medium- or long-time variations affect the large-scale system; 4) Achieving the above, while being scalable and modular. The purpose of the present paper is to provide the main features of the proposed control design methodology.
{"title":"Nonlinear Control of Large Scale complex Systems using Convex Control Design tools","authors":"E. Kosmatopoulos, S. Baldi, K. Aboudolas, D. Rovas, A. Papachristodoulou, P. Ioannou","doi":"10.1109/MED.2011.5983147","DOIUrl":"https://doi.org/10.1109/MED.2011.5983147","url":null,"abstract":"Based on recent advances on convex design for Large-Scale Control Systems (LSCSs) and robust and efficient LSCS self-tuning/adaptation, a methodology is proposed in this paper which aims at providing an integrated LSCS-design, applicable to large-scale systems of arbitrary scale, heterogeneity and complexity and capable of: 1) Providing stable, efficient and arbitrarily-close-to-optimal LSCS performance; 2) Being able to incorporate a variety of constraints, including limited control constraints as well as constraints that are nonlinear functions of the system controls and outputs (sensor measurements); 3) Being intrinsically self-tunable, able to rapidly and efficiently optimize LSCS performance when short-, medium- or long-time variations affect the large-scale system; 4) Achieving the above, while being scalable and modular. The purpose of the present paper is to provide the main features of the proposed control design methodology.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"86 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114047465","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 : 2011-06-20DOI: 10.1109/MED.2011.5983109
A. Barreiro, A. Baños, S. Dormido
Reset controllers provide a simple way to improve performance when controlling strongly traded-off plants. A reset controller operates most of the time as a linear system, but when some condition holds, it performs a zero resetting action on its state. Recently, some generalizations have been proposed: anticipation of the condition with the so-called reset band, relaxation of the action applying partial reset, etc. There is a lack of analysis tools for reset systems with reset band. In this paper we address the problem of existence, detection and stability of limit cycles by means of Poincaré maps. The results give also information on pathologies such as Zenoness. The presented approach is complementary to describing function analysis, in order to reveal the ability of reset controllers for overcoming fundamental limitations in the frequency domain.
{"title":"Reset Control Systems with Reset Band: Well-posedness and Limit Cycles Analysis","authors":"A. Barreiro, A. Baños, S. Dormido","doi":"10.1109/MED.2011.5983109","DOIUrl":"https://doi.org/10.1109/MED.2011.5983109","url":null,"abstract":"Reset controllers provide a simple way to improve performance when controlling strongly traded-off plants. A reset controller operates most of the time as a linear system, but when some condition holds, it performs a zero resetting action on its state. Recently, some generalizations have been proposed: anticipation of the condition with the so-called reset band, relaxation of the action applying partial reset, etc. There is a lack of analysis tools for reset systems with reset band. In this paper we address the problem of existence, detection and stability of limit cycles by means of Poincaré maps. The results give also information on pathologies such as Zenoness. The presented approach is complementary to describing function analysis, in order to reveal the ability of reset controllers for overcoming fundamental limitations in the frequency domain.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122382459","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 : 2011-06-20DOI: 10.1109/MED.2011.5983119
Marco P. Soares dos Santos, J. Ferreira, C. N. Boeri
As the performance requirements become more demanding and the plants become more and more complex, control designers were naturally forced to look beyond traditional linear control theory and attempt to find more advanced nonlinear methods. However, it has been very difficult to overcome the huge gap between the current knowledge, researched by the scientific automatic control community, and its application in the industrial environment. In this paper, it is proposed to consider the nonlinear PID as the method to deal with this hitch. The current nonlinear PID methodologies were reviewed and their shortcomings presented. The main aim is to objectify new research lines that may enhance it, in order to ensure that the evolution of industrial control systems is strongly linked to that of the control techniques.
{"title":"Bridging the gap between advanced control methods and industrial control applications: Shortcomings of the current nonlinear PID Method and new research lines to its enhancing","authors":"Marco P. Soares dos Santos, J. Ferreira, C. N. Boeri","doi":"10.1109/MED.2011.5983119","DOIUrl":"https://doi.org/10.1109/MED.2011.5983119","url":null,"abstract":"As the performance requirements become more demanding and the plants become more and more complex, control designers were naturally forced to look beyond traditional linear control theory and attempt to find more advanced nonlinear methods. However, it has been very difficult to overcome the huge gap between the current knowledge, researched by the scientific automatic control community, and its application in the industrial environment. In this paper, it is proposed to consider the nonlinear PID as the method to deal with this hitch. The current nonlinear PID methodologies were reviewed and their shortcomings presented. The main aim is to objectify new research lines that may enhance it, in order to ensure that the evolution of industrial control systems is strongly linked to that of the control techniques.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122432061","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 : 2011-06-20DOI: 10.1109/MED.2011.5983059
A. Balestrino, A. Caiti, E. Crisostomi
A novel statistical indicator is introduced to evaluate the nonlinear behaviour of dynamical systems, as a support to other classic methods (e.g., Lyapunov exponents, entropy of curve methods). According to the theoretical properties of the proposed method, it is possible to infer the actual dimension of the phase space where the system dynamics evolve; it is possible to differentiate linear from nonlinear systems also in the presence of measurement noise; different dynamical systems that appear similar according to other indicators are further correctly distinguished. Theoretical expectations are confirmed by several examples of classic benchmark dynamical systems.
{"title":"A statistical tool for analysing nonlinear properties of dynamical systems","authors":"A. Balestrino, A. Caiti, E. Crisostomi","doi":"10.1109/MED.2011.5983059","DOIUrl":"https://doi.org/10.1109/MED.2011.5983059","url":null,"abstract":"A novel statistical indicator is introduced to evaluate the nonlinear behaviour of dynamical systems, as a support to other classic methods (e.g., Lyapunov exponents, entropy of curve methods). According to the theoretical properties of the proposed method, it is possible to infer the actual dimension of the phase space where the system dynamics evolve; it is possible to differentiate linear from nonlinear systems also in the presence of measurement noise; different dynamical systems that appear similar according to other indicators are further correctly distinguished. Theoretical expectations are confirmed by several examples of classic benchmark dynamical systems.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"104 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124021211","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 : 2011-06-20DOI: 10.1109/MED.2011.5983131
Chris Sconyers, I. Raptis, G. Vachtsevanos
The future of flight is autonomous and semi-autonomous vehicles. By supporting or replacing UAV operators, control systems become key for increasing UAV autonomy. This paper presents a novel controller and trajectory generator module for an unmanned rotorcraft, with the goal of tracking a moving ground target using sensor measurements and limited or no operator input. A backstepping control scheme is chosen to guarantee stability and minimize the number of operating modes. We implement a trajectory generator for the rotorcarft to seek and orbit around a moving ground target. The applicability of the combined controller-trajectory generator module is verified through numerical simulations.
{"title":"Rotorcraft control and trajectory generation for target tracking","authors":"Chris Sconyers, I. Raptis, G. Vachtsevanos","doi":"10.1109/MED.2011.5983131","DOIUrl":"https://doi.org/10.1109/MED.2011.5983131","url":null,"abstract":"The future of flight is autonomous and semi-autonomous vehicles. By supporting or replacing UAV operators, control systems become key for increasing UAV autonomy. This paper presents a novel controller and trajectory generator module for an unmanned rotorcraft, with the goal of tracking a moving ground target using sensor measurements and limited or no operator input. A backstepping control scheme is chosen to guarantee stability and minimize the number of operating modes. We implement a trajectory generator for the rotorcarft to seek and orbit around a moving ground target. The applicability of the combined controller-trajectory generator module is verified through numerical simulations.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"1940 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129286401","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 : 2011-06-20DOI: 10.1109/MED.2011.5983104
M. Bibuli, G. Bruzzone, M. Caccia, A. Ortiz, T. Vogele, M. Eich, L. Drikos, Y. Koveos, E. Kolyvas, F. Spadoni, A. Vergine, K. Tanneberger, A. Todorova, I. Gaviotis, V. Apostolopoulou
In this paper an overall description of the MINOAS project is reported. The project proposes an innovative approach to improve ship inspection methodology, complementing human personnel with cutting-edge robotic platforms, able to autonomously carry out inspection tasks, allowing in this way the human operators to ‘virtually’ execute the inspection from a control room. This paper provides an overview of the project motivations, concept and goals, specifications of the MINOAS system, in particular with respect to an accurate analysis of the tasks executed during vessel inspections, the proposed overall architecture and the classes of robots that will be considered as a possible help to the human inspector.
{"title":"The MINOAS project: Marine INspection rObotic Assistant System","authors":"M. Bibuli, G. Bruzzone, M. Caccia, A. Ortiz, T. Vogele, M. Eich, L. Drikos, Y. Koveos, E. Kolyvas, F. Spadoni, A. Vergine, K. Tanneberger, A. Todorova, I. Gaviotis, V. Apostolopoulou","doi":"10.1109/MED.2011.5983104","DOIUrl":"https://doi.org/10.1109/MED.2011.5983104","url":null,"abstract":"In this paper an overall description of the MINOAS project is reported. The project proposes an innovative approach to improve ship inspection methodology, complementing human personnel with cutting-edge robotic platforms, able to autonomously carry out inspection tasks, allowing in this way the human operators to ‘virtually’ execute the inspection from a control room. This paper provides an overview of the project motivations, concept and goals, specifications of the MINOAS system, in particular with respect to an accurate analysis of the tasks executed during vessel inspections, the proposed overall architecture and the classes of robots that will be considered as a possible help to the human inspector.","PeriodicalId":146203,"journal":{"name":"2011 19th Mediterranean Conference on Control & Automation (MED)","volume":"506 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117036653","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：