A novel 6-degree of freedom (DOF) posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive h...A novel 6-degree of freedom (DOF) posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive half-ball shaped end-effector, and the positioners together with the wing are considered as a 3-PPPS (P denotes a prismatic joint and S denotes a spherical joint) redundantly actuated parallel mechanism. The kinematic model of this system is established and a trajectory planning method is introduced. A complete analysis of inverse dynamics is carried out with the Newton-Euler algorithm, which is used to find the desired actuating torque in the design and path planning phase. Simulation analysis of the displacement and actuating torque of each joint of the positioners based on inverse kinematics and dynamics is conducted, and the results show that the system is feasible for the posture alignment of aircraft wings.展开更多
Aircraft digital flexible assembly fixture and technologies are widely used in developed countries, while the traditional jig-based assembly mode is still used in China. The application study of aircraft digital flexi...Aircraft digital flexible assembly fixture and technologies are widely used in developed countries, while the traditional jig-based assembly mode is still used in China. The application study of aircraft digital flexible assembly system is just beginning in our country recently. To meet the requirements of automated posture alignment and join in digital assembly system for large aircraft components, a novel fitting fixture called 3-axis actuator is developed. On the basis of the actuators, three kinds of posture alignment system for large aircraft components are proposed, including the non-redundant system, the redundant actuating system, and the redundant leg system, and their constitutions and properties are introduced. Through deriving the feeding transmission stiffness model of single actuator and analyzing the inverse kinematics of these systems, the relationship between the external force and the changes of position and orientation of large aircraft component is obtained, and then the postural alignment stiffness models are established. With the method mentioned above, the postural alignment stiffness of three systems is computed by using the algebraic formulate, and the results show that redundant properties can increase system＇s postural alignment stiffness. As an example, a optimized layout of the assembly system for a given model of aircraft is developed, the results of application show that the layout has many advantages, such as high accuracy, stiffness, stability, reliability, efficiency and flexible, which can satisfy the requirement of aircraft digital assembly system well. The proposed study of postural alignment stiffness for different systems can supply the theoretic support for the optimization layout design of aircraft digital assembly system, and contribute to evaluate the system working performance of systems.展开更多
Industrial surface inspection is crucial for the manufacture of high-end equipment across industries,with precise image acquisition being fundamental.Existing imaging systems often lack flexibility,they are restricted...Industrial surface inspection is crucial for the manufacture of high-end equipment across industries,with precise image acquisition being fundamental.Existing imaging systems often lack flexibility,they are restricted to specific objects,and face challenges in industrial structures without standardized computer-aided design(CAD)models or with complex surfaces.Inspired by human-like multidimensional observation,this study developed a universal image acquisition system based on measured point clouds,offering strong adaptability and robustness in complex industrial settings.The system is divided into three layers:the physical layer responsible for hardware integration,the interaction layer that facilitates bidirectional data exchange with the control layer,and the control layer integrating a new paradigm of multiple intelligent algorithms.The physical layer incorporates 2D and 3D cameras,turntables and industrial robots,enhancing the flexibility and compatibility of imaging.The interaction layer manages bidirectional information transmission and data exchange,offering a visualized area to enhance the user interaction experience.The control layer consists of point cloud preprocessing,primitive segmentation,viewpoint generation and pose estimation algorithms,using point cloud-based viewpoint generation and trajectory planning for high-precision image acquisition applicable to complex surface inspections across scenarios and structures.The system’s utility is demonstrated through a software and hardware algorithm platform and an interactive interface.Experimental validation on curved surfaces of different configurations and sizes confirms its universal image acquisition advantages.This system promises to introduce a cost-effective,versatile solution for complex surfaces,driving adoption across diverse industrial scenarios.展开更多
文摘A novel 6-degree of freedom (DOF) posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive half-ball shaped end-effector, and the positioners together with the wing are considered as a 3-PPPS (P denotes a prismatic joint and S denotes a spherical joint) redundantly actuated parallel mechanism. The kinematic model of this system is established and a trajectory planning method is introduced. A complete analysis of inverse dynamics is carried out with the Newton-Euler algorithm, which is used to find the desired actuating torque in the design and path planning phase. Simulation analysis of the displacement and actuating torque of each joint of the positioners based on inverse kinematics and dynamics is conducted, and the results show that the system is feasible for the posture alignment of aircraft wings.
文摘Aircraft digital flexible assembly fixture and technologies are widely used in developed countries, while the traditional jig-based assembly mode is still used in China. The application study of aircraft digital flexible assembly system is just beginning in our country recently. To meet the requirements of automated posture alignment and join in digital assembly system for large aircraft components, a novel fitting fixture called 3-axis actuator is developed. On the basis of the actuators, three kinds of posture alignment system for large aircraft components are proposed, including the non-redundant system, the redundant actuating system, and the redundant leg system, and their constitutions and properties are introduced. Through deriving the feeding transmission stiffness model of single actuator and analyzing the inverse kinematics of these systems, the relationship between the external force and the changes of position and orientation of large aircraft component is obtained, and then the postural alignment stiffness models are established. With the method mentioned above, the postural alignment stiffness of three systems is computed by using the algebraic formulate, and the results show that redundant properties can increase system＇s postural alignment stiffness. As an example, a optimized layout of the assembly system for a given model of aircraft is developed, the results of application show that the layout has many advantages, such as high accuracy, stiffness, stability, reliability, efficiency and flexible, which can satisfy the requirement of aircraft digital assembly system well. The proposed study of postural alignment stiffness for different systems can supply the theoretic support for the optimization layout design of aircraft digital assembly system, and contribute to evaluate the system working performance of systems.
基金supported by the National Natural Science Foundation of China(Nos.62303457 and U21A20482)Beijing Municipal Natural Science Foundation,China(No.4252053)Project funded by Beijing Zhongke Huiling Robot Technology Co.,Ltd,China(No.E5D11703).
文摘Industrial surface inspection is crucial for the manufacture of high-end equipment across industries,with precise image acquisition being fundamental.Existing imaging systems often lack flexibility,they are restricted to specific objects,and face challenges in industrial structures without standardized computer-aided design(CAD)models or with complex surfaces.Inspired by human-like multidimensional observation,this study developed a universal image acquisition system based on measured point clouds,offering strong adaptability and robustness in complex industrial settings.The system is divided into three layers:the physical layer responsible for hardware integration,the interaction layer that facilitates bidirectional data exchange with the control layer,and the control layer integrating a new paradigm of multiple intelligent algorithms.The physical layer incorporates 2D and 3D cameras,turntables and industrial robots,enhancing the flexibility and compatibility of imaging.The interaction layer manages bidirectional information transmission and data exchange,offering a visualized area to enhance the user interaction experience.The control layer consists of point cloud preprocessing,primitive segmentation,viewpoint generation and pose estimation algorithms,using point cloud-based viewpoint generation and trajectory planning for high-precision image acquisition applicable to complex surface inspections across scenarios and structures.The system’s utility is demonstrated through a software and hardware algorithm platform and an interactive interface.Experimental validation on curved surfaces of different configurations and sizes confirms its universal image acquisition advantages.This system promises to introduce a cost-effective,versatile solution for complex surfaces,driving adoption across diverse industrial scenarios.
