An approach to sequence planning for on-orbit assembly of large space truss structures in a multirobot environment is presented. A hierarchical representation of large space truss structures at the structural volume e...An approach to sequence planning for on-orbit assembly of large space truss structures in a multirobot environment is presented. A hierarchical representation of large space truss structures at the structural volume element level and strut level is adopted. The representation of connectivity matrix and directed graph is respectively presented at the strut level and SVE level. The multirobot environment that consists of autonomous space robots and struts is supposed. Then the multirobot serial assembly strategy,assembly states,assembly tasks and assembly sequences are described. The assembly sequence planning algorithms at the strut level and SVE level are respectively discussed. The results of the simulations show that this approach is feasible and efficient. Two extensions of this approach include more accurate assessment of the efficiency representation and improvements in planning algorithm. In the future,the assembly sequence planning of more large space truss structures and complex multirobot environments and assembly tasks will be considered.展开更多
The trend towards automation and intelligence in aircraft final assembly testing has led to a new demand for autonomous perception of unknown cockpit operation scenes in robotic collaborative airborne system testing.T...The trend towards automation and intelligence in aircraft final assembly testing has led to a new demand for autonomous perception of unknown cockpit operation scenes in robotic collaborative airborne system testing.To address this demand,a robotic automated 3D reconstruction cell which enables to autonomously plan the robot end-camera’s trajectory is developed for image acquisition and 3D modeling of the cockpit operation scene.A continuous viewpoint path planning algorithm is proposed that incorporates both 3D reconstruction quality and robot path quality into optimization process.Smoothness metrics for viewpoint position paths and orientation paths are introduced together for the first time in 3D reconstruction.To ensure safe and effective movement,two spatial constraints,Domain of View Admissible Position(DVAP)and Domain of View Admissible Orientation(DVAO),are implemented to account for robot reachability and collision avoidance.By using diffeomorphism mapping,the orientation path is transformed into 3D,consistent with the position path.Both orientation and position paths can be optimized in a unified framework to maximize the gain of reconstruction quality and path smoothness within DVAP and DVAO.The reconstruction cell is capable of automatic data acquisition and fine scene modeling,using the generated robot C-space trajectory.Simulation and physical scene experiments have confirmed the effectiveness of the proposed method to achieve highprecision 3D reconstruction while optimizing robot motion quality.展开更多
Quality function deployment(QFD)is an effective method that helps companies analyze customer requirements(CRs).These CRs are then turned into product or service characteristics,which are translated to other attributes...Quality function deployment(QFD)is an effective method that helps companies analyze customer requirements(CRs).These CRs are then turned into product or service characteristics,which are translated to other attributes.With the QFD method,companies could design or improve the quality of products or services close to CRs.To increase the effectiveness of QFD,we propose an improved method based on Pythagorean fuzzy sets(PFSs).We apply an extended method to obtain the group consensus evaluation matrix.We then use a combined weight determining method to integrate former weights to objective weights derived from the evaluation matrix.To determine the exact score of each PFS in the evaluation matrix,we develop an improved score function.Lastly,we apply the proposed method to a case study on assembly robot design evaluation.展开更多
Presented in this paper is a framework for the implementation of a robotic percussive riveting system, a new robot application for aircraft assembly. It is shown here that a successful robot application to the automat...Presented in this paper is a framework for the implementation of a robotic percussive riveting system, a new robot application for aircraft assembly. It is shown here that a successful robot application to the automation of a process requires in-depth research of the process and the interaction with the robot. For this purpose, a process plan- ning-driven approach is proposed to guide a robot applica- tion research. A typical process planning will involve a list of key considerations including： process sequence, process parameters, process tooling, and process control. Through this list, a number of key research issues are identified for robotic percussive riveting, such as rivet pattern planning, rivet time determination, rivet tooling design and rivet insertion control. The detailed research on these issues has effectively created know-how for the successful implemen- tation of our robotic percussive riveting system.展开更多
文摘An approach to sequence planning for on-orbit assembly of large space truss structures in a multirobot environment is presented. A hierarchical representation of large space truss structures at the structural volume element level and strut level is adopted. The representation of connectivity matrix and directed graph is respectively presented at the strut level and SVE level. The multirobot environment that consists of autonomous space robots and struts is supposed. Then the multirobot serial assembly strategy,assembly states,assembly tasks and assembly sequences are described. The assembly sequence planning algorithms at the strut level and SVE level are respectively discussed. The results of the simulations show that this approach is feasible and efficient. Two extensions of this approach include more accurate assessment of the efficiency representation and improvements in planning algorithm. In the future,the assembly sequence planning of more large space truss structures and complex multirobot environments and assembly tasks will be considered.
基金supported by the National Key Research and Development Program of China(2019YFB1707505)the National Natural Science Foundation of China(Grant No.52005436)。
文摘The trend towards automation and intelligence in aircraft final assembly testing has led to a new demand for autonomous perception of unknown cockpit operation scenes in robotic collaborative airborne system testing.To address this demand,a robotic automated 3D reconstruction cell which enables to autonomously plan the robot end-camera’s trajectory is developed for image acquisition and 3D modeling of the cockpit operation scene.A continuous viewpoint path planning algorithm is proposed that incorporates both 3D reconstruction quality and robot path quality into optimization process.Smoothness metrics for viewpoint position paths and orientation paths are introduced together for the first time in 3D reconstruction.To ensure safe and effective movement,two spatial constraints,Domain of View Admissible Position(DVAP)and Domain of View Admissible Orientation(DVAO),are implemented to account for robot reachability and collision avoidance.By using diffeomorphism mapping,the orientation path is transformed into 3D,consistent with the position path.Both orientation and position paths can be optimized in a unified framework to maximize the gain of reconstruction quality and path smoothness within DVAP and DVAO.The reconstruction cell is capable of automatic data acquisition and fine scene modeling,using the generated robot C-space trajectory.Simulation and physical scene experiments have confirmed the effectiveness of the proposed method to achieve highprecision 3D reconstruction while optimizing robot motion quality.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.71501135,71771156)the 2018 Key Project of the Key Research Institute of Humanities and Social Sciences in Sichuan Province(Nos.Xq18A01,LYC18-02)+2 种基金the Electronic Commerce and Modem Logistics Research Center Program,the Key Research Base of Humanities and Social Science,Sichuan Provincial Education Department(No.DSWL18-2)the Spark Project of Innovation at Sichuan University(No.2018hhs-43)the Scholarship from China Scholarship Council(No.201706240012).
文摘Quality function deployment(QFD)is an effective method that helps companies analyze customer requirements(CRs).These CRs are then turned into product or service characteristics,which are translated to other attributes.With the QFD method,companies could design or improve the quality of products or services close to CRs.To increase the effectiveness of QFD,we propose an improved method based on Pythagorean fuzzy sets(PFSs).We apply an extended method to obtain the group consensus evaluation matrix.We then use a combined weight determining method to integrate former weights to objective weights derived from the evaluation matrix.To determine the exact score of each PFS in the evaluation matrix,we develop an improved score function.Lastly,we apply the proposed method to a case study on assembly robot design evaluation.
文摘Presented in this paper is a framework for the implementation of a robotic percussive riveting system, a new robot application for aircraft assembly. It is shown here that a successful robot application to the automation of a process requires in-depth research of the process and the interaction with the robot. For this purpose, a process plan- ning-driven approach is proposed to guide a robot applica- tion research. A typical process planning will involve a list of key considerations including： process sequence, process parameters, process tooling, and process control. Through this list, a number of key research issues are identified for robotic percussive riveting, such as rivet pattern planning, rivet time determination, rivet tooling design and rivet insertion control. The detailed research on these issues has effectively created know-how for the successful implemen- tation of our robotic percussive riveting system.
