The service life and stability of flexible pressure sensors vary with the interfacial toughness of these multilayered structures, which are principally fabricated by adhesive bonding, hot melting, and interconnection....
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In multibody system dynamics, the absolute nodal coordinate formulation （ANCF） uses power functions as interpolating polynomials to describe the displacement field. It can get accurate results for flexible bodies th...
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In multibody system dynamics, the absolute nodal coordinate formulation （ANCF） uses power functions as interpolating polynomials to describe the displacement field. It can get accurate results for flexible bodies that undergo large deformation and large rotation. However, the power functions are irrational representation which cannot describe the complex shapes precisely, especially for circular and conic sections. Different from the ANCF representation, the rational absolute nodal coordinate formulation （RANCF） utilizes rational basis functions to describe geometric shapes, which allows the accurate representation of complicated displacement and deformation in dynamics modeling. In this paper, the relationships between the rational surface and volume and the RANCF finite element are provided, and the generalized transformation matrices are established correspondingly. Using these transformation matrices, a new four-node three-dimensional RANCF plate element and a new eight-node three-dimensional RANCF solid element are proposed based on the RANCF. Numerical examples are given to demonstrate the applicability of the proposed elements. It is shown that the proposed elements can depict the geometric characteristics and structure configurations precisely, and lead to better convergence in comparison with the ANCF finite elements for the dynamic analysis of flexible bodies.
Recently,with the rapid development of aerospacetechnology,an increasing number of spacecraft is being launched into ***,the demands for on-orbit servicing(OOS)missions are rapidly *** robotics is one of the most pro...
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Recently,with the rapid development of aerospacetechnology,an increasing number of spacecraft is being launched into ***,the demands for on-orbit servicing(OOS)missions are rapidly *** robotics is one of the most promising approaches for various OOS missions;thus,research on spacerobotics technologies for OOS has attracted increased attention from space agencies and universities *** this paper,we review the structures,ground verification,and onorbit kinematics calibration technologies of spaceroboticsystems for ***,we systematically summarize the development of spaceroboticsystems and OOS programs based on space ***,according to the structures and applications,these systems are divided into three categories:large space manipulators,humanoid space robots,and small space *** to the capture mechanisms adopted,the end-effectors are systematically ***,the ground verification facilities used to simulate a microgravity environment are summarized and ***,the on-orbit kinematics calibration technologies are discussed and analyzed compared with the kinematics calibration technologies of industrial manipulators with regard to four ***,the development trends of the structures,verification,and calibration technologies are discussed to extend this review work.
In this paper,a method of predicting the motion state of a moving target in the base coordinate system by hand-eye vision and the position and attitude of the end is *** predicted value is used as the velocity feedfor...
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In this paper,a method of predicting the motion state of a moving target in the base coordinate system by hand-eye vision and the position and attitude of the end is *** predicted value is used as the velocity feedforward,and the position-based visual servo method is used to plan the velocity of the end of the *** overcomes the influence of end coordinate system motion on target prediction in a discrete system and introduces an integral control method to compensate for the prediction velocity,eliminating the end tracking error caused by target velocity prediction *** effectiveness of this method is verified by simulation and experiment.
Thermal controllers equipped with phase-change materials are widely used for maintaining the moderate temperatures of various electric devices used in spacecraft. Yet, the structures of amounts of thermal controllers ...
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Thermal controllers equipped with phase-change materials are widely used for maintaining the moderate temperatures of various electric devices used in spacecraft. Yet, the structures of amounts of thermal controllers add up to such a large value that restricts the employment of scientific devices due to the limit of rocket capacity. A lightweight structure of phase-change thermal controllers has been one of the main focuses of spacecraft design engineering. In this work, we design a lightweight phase-change thermal controller structure based on lattice cells. The structure is manufactured entirely with AlSi10 Mg by direct metal laser melting. The dimensions of the structure are 230 mm × 170 mm × 15 mm, and the mass is 190 g, which is 60% lighter than most traditional structures(500–600 g) with the same dimensions. The 3 D-printed structure can reduce the risk of leakage at soldering manufacture by a welding process. Whether the strength of the designed structure is sufficient is determined through mechanical analysis and experiments. Thermal test results show that the thermal capacity of the lattice-based thermal controller is increased by50% compared to that of traditional controllers with the same volume.
spaceintelligentroboticsystems are expected to play an increasingly important role in the *** robotic onorbital service,whose key is the tracking and capturing technology,becomes research hot in recent *** this pap...
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ISBN:
(纸本)9781479919819
spaceintelligentroboticsystems are expected to play an increasingly important role in the *** robotic onorbital service,whose key is the tracking and capturing technology,becomes research hot in recent *** this paper,the authors propose a vision servo control system for target *** manipulator will be an intelligentroboticsystem with large-scale movement,functional agility,and autonomous ability,and it can be operated by astronauts in the space station or be controlled by the ground operator in the remote operation *** realize the autonomous movement and capture mission of SRM,a kind of autonomous programming strategy based on multi-camera vision fusion is designed and the selection principle of object visual position and orientation measurement information is defined for the better *** control system hierarchy is designed and reliability is considering to guarantee the abilities of control *** last,a ground experiment system is set up based on the concept of robotic control *** that,the autonomous target capturing experiments are *** experiment results validate the proposed algorithm,and demonstrates that the control system can fulfill the needs of function,real-time and reliability.
In the process of on orbit capture, there is a large contact and impact between the manipulator and the target. The flexibility of variable stiffness joints can effectively reduce the collision force and improve the c...
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The cogging torque is the inherent characteristic of permanent motors with the cogging. The cogging torque reduces the stability of the motor, especially in the status of the low speed. A compensation method based on ...
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Focusing on task of space manipulator assisting docking, a visual-servo close loop control method is proposed, the full system simulation model established, and simulated in control-dynamics closed loop for verificati...
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The manipulator launched with the TianHe capsule is currently the most complex, intelligent, and integrated space intelligence system in China. It indicates that China has become the world's third country after Ca...
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