Robots are finding increasing application in aircraft composite structure assembly due to their flexibility and the growing demand of aircraft manufacturers for high production rates.The contact force of the composite...Robots are finding increasing application in aircraft composite structure assembly due to their flexibility and the growing demand of aircraft manufacturers for high production rates.The contact force of the composite frame in a robotic assembly of the aircraft composite fuselage panel can hardly be controlled due to the multi-surface variable contact stiffness caused by compliance and complex shape with multiple mating surfaces.The paper proposes a robotic assembly system for the aircraft composite fuselage frame with a compliant contact force control strategy using the Gaussian process surrogate model.First,a robotic assembly system is introduced,and the global coordinate system transformation model is built.Then,a compliant force control architecture is designed to generate the desired output force.Subsequently,a Gaussian process surrogate model with uncertainties is utilized to model the complicated relationship between the robot’s output force and the normal contact force acting on the mating surface of the composite frame.Furthermore,an optimal contact force control strategy is implemented to improve the contact quality.Finally,an experiment demonstrates that the proposed methodology can ensure that the contact force on each surface is within the limit of the engineering specification and uniformly distributed,improving the quality compared to the traditional assembly process.展开更多
Hollow structure microspheres with composite polymeric-Laponite shells were prepared by electrostatic self-assembly of Laponite on the polymeric hollow microspheres in this work.The multilayer hydrophilic core/hydroph...Hollow structure microspheres with composite polymeric-Laponite shells were prepared by electrostatic self-assembly of Laponite on the polymeric hollow microspheres in this work.The multilayer hydrophilic core/hydrophobic shell polymer latex particles containing carboxyl groups inside were first synthesized via seeded emulsion polymerization,followed by alkali treatment,generating polymeric hollow microspheres.Then,polyethyleneimine（PEI） and Laponite were alternately electrostatic adsorbed on the prepared polymeric hollow microspheres to form polymeric-Laponite composite hollow microspheres.It was indicated that the morphology of alkali-treated microspheres could be tuned through simply altering the dosage of alkali used in the post-treatment process.Along with the increasing of the coating layers,the zeta potential of microspheres absorbed PEI or Laponite approximately tended to be constant respectively,and the thickness of Laponite layer around the hollow microspheres increased clearly,getting more uniform and homogenous.Furthermore,the corresponding polymeric-Laponite hollow microspheres showed high pressure resistance ability compared to the polymeric hollow microspheres.展开更多
Aiming at the characteristics of obvious block division and strong discreteness in the assembly production mode of electronic products,this paper proposes a composite U-shaped flexible assembly line model,and establis...Aiming at the characteristics of obvious block division and strong discreteness in the assembly production mode of electronic products,this paper proposes a composite U-shaped flexible assembly line model,and establishes a multi-objective optimization mathematical model on this basis.According to the characteristics of the model,the improved ranked positional weight(RPW)method is used to adjust the generation process of the initial solution of the genetic algorithm,so that the genetic algorithm can be applied to the block task model.At the same time,the adaptive cross mutation factor is used on the premise that tasks between different blocks are not crossed during cross mutation,which effectively improves the probability of excellent individuals retaining.After that,the algorithm is used to iterate to obtain the optimal solution task assignment.Finally,the algorithm results are compared with actual production data,which verifies the validity and feasibility of the assembly line model for discrete production mode proposed in this paper.展开更多
The goal of this study was to develop and design a composite proton exchange membrane（PEM） and membrane electrode assembly（MEA） that are suitable for the PEM based water electrolysis system. In particular,it focus...The goal of this study was to develop and design a composite proton exchange membrane（PEM） and membrane electrode assembly（MEA） that are suitable for the PEM based water electrolysis system. In particular,it focuses on the development of sulphonated polyether ether ketone（SPEEK） based membranes and caesium salt of silico-tungstic acid（Cs Si WA） matrix compared with one of the transition metal oxides such as titanium dioxide（TiO2）, silicon dioxide（SiO2） and zirconium dioxide（ZrO2）. The resultant membranes have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, ion exchange capacity（IEC）, water uptake and atomic force microscopy. Comparative studies on the performance of MEAs were also conducted utilizing impregnation-reduction and conventional brush coating methods. The PEM electrolysis performance of SPEEK-Cs Si WA-ZrO2 composite membrane was more superior than that of other membranes involved in this study. Electrochemical characterization shows that a maximum current density of 1.4 A/cm^2 was achieved at 60 °C, explained by an increased concentration of protonic sites available at the interface.展开更多
During the organization of original photographic materials,the authors identified that the image labeled"OE-2"in Figure 1A had been erroneously replaced with another tillering phenotype-related plant image c...During the organization of original photographic materials,the authors identified that the image labeled"OE-2"in Figure 1A had been erroneously replaced with another tillering phenotype-related plant image captured simultaneously from the same directory.This substitution resulted in the incorrect incorporation of the"OE-2"image during the composite figure assembly process.展开更多
基金This study was supported by the Aeronautical Manufacturing Technology Institute,COMAC.
文摘Robots are finding increasing application in aircraft composite structure assembly due to their flexibility and the growing demand of aircraft manufacturers for high production rates.The contact force of the composite frame in a robotic assembly of the aircraft composite fuselage panel can hardly be controlled due to the multi-surface variable contact stiffness caused by compliance and complex shape with multiple mating surfaces.The paper proposes a robotic assembly system for the aircraft composite fuselage frame with a compliant contact force control strategy using the Gaussian process surrogate model.First,a robotic assembly system is introduced,and the global coordinate system transformation model is built.Then,a compliant force control architecture is designed to generate the desired output force.Subsequently,a Gaussian process surrogate model with uncertainties is utilized to model the complicated relationship between the robot’s output force and the normal contact force acting on the mating surface of the composite frame.Furthermore,an optimal contact force control strategy is implemented to improve the contact quality.Finally,an experiment demonstrates that the proposed methodology can ensure that the contact force on each surface is within the limit of the engineering specification and uniformly distributed,improving the quality compared to the traditional assembly process.
基金supported by Heilongjiang Provincial Natural Science Foundation for Youth, China (No. QC2014C052)Fund of Key Laboratory of Advanced materials of Ministry of Education (No. 2016AML06)the training project for innovation and entrepreneurship of the Harbin University of Science and Technology, China (2016)
文摘Hollow structure microspheres with composite polymeric-Laponite shells were prepared by electrostatic self-assembly of Laponite on the polymeric hollow microspheres in this work.The multilayer hydrophilic core/hydrophobic shell polymer latex particles containing carboxyl groups inside were first synthesized via seeded emulsion polymerization,followed by alkali treatment,generating polymeric hollow microspheres.Then,polyethyleneimine（PEI） and Laponite were alternately electrostatic adsorbed on the prepared polymeric hollow microspheres to form polymeric-Laponite composite hollow microspheres.It was indicated that the morphology of alkali-treated microspheres could be tuned through simply altering the dosage of alkali used in the post-treatment process.Along with the increasing of the coating layers,the zeta potential of microspheres absorbed PEI or Laponite approximately tended to be constant respectively,and the thickness of Laponite layer around the hollow microspheres increased clearly,getting more uniform and homogenous.Furthermore,the corresponding polymeric-Laponite hollow microspheres showed high pressure resistance ability compared to the polymeric hollow microspheres.
文摘Aiming at the characteristics of obvious block division and strong discreteness in the assembly production mode of electronic products,this paper proposes a composite U-shaped flexible assembly line model,and establishes a multi-objective optimization mathematical model on this basis.According to the characteristics of the model,the improved ranked positional weight(RPW)method is used to adjust the generation process of the initial solution of the genetic algorithm,so that the genetic algorithm can be applied to the block task model.At the same time,the adaptive cross mutation factor is used on the premise that tasks between different blocks are not crossed during cross mutation,which effectively improves the probability of excellent individuals retaining.After that,the algorithm is used to iterate to obtain the optimal solution task assignment.Finally,the algorithm results are compared with actual production data,which verifies the validity and feasibility of the assembly line model for discrete production mode proposed in this paper.
文摘The goal of this study was to develop and design a composite proton exchange membrane（PEM） and membrane electrode assembly（MEA） that are suitable for the PEM based water electrolysis system. In particular,it focuses on the development of sulphonated polyether ether ketone（SPEEK） based membranes and caesium salt of silico-tungstic acid（Cs Si WA） matrix compared with one of the transition metal oxides such as titanium dioxide（TiO2）, silicon dioxide（SiO2） and zirconium dioxide（ZrO2）. The resultant membranes have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, ion exchange capacity（IEC）, water uptake and atomic force microscopy. Comparative studies on the performance of MEAs were also conducted utilizing impregnation-reduction and conventional brush coating methods. The PEM electrolysis performance of SPEEK-Cs Si WA-ZrO2 composite membrane was more superior than that of other membranes involved in this study. Electrochemical characterization shows that a maximum current density of 1.4 A/cm^2 was achieved at 60 °C, explained by an increased concentration of protonic sites available at the interface.
文摘During the organization of original photographic materials,the authors identified that the image labeled"OE-2"in Figure 1A had been erroneously replaced with another tillering phenotype-related plant image captured simultaneously from the same directory.This substitution resulted in the incorrect incorporation of the"OE-2"image during the composite figure assembly process.
