Background Assembly guided by paper documents is the most widespread type used in the process of aircraft cable assembly.This process is very complicated and requires assembly workers with high-level skills.The techno...Background Assembly guided by paper documents is the most widespread type used in the process of aircraft cable assembly.This process is very complicated and requires assembly workers with high-level skills.The technologies of wearable Augmented Reality(AR)and portable visual inspection can be exploited to improve the efficiency and the quality of cable assembly.Methods In this study,we propose a smart assistance system for cable assembly that combines wearable AR with portable visual inspection.Specifically,a portable visual device based on binocular vision and deep learning is developed to realize fast detection and recognition of cable brackets that are installed on aircraft airframes.A Convolutional Neural Network(CNN)is then developed to read the texts on cables after images are acquired from the camera of the wearable AR device.An authoring tool that was developed to create and manage the assembly process is proposed to realize visual guidance of the cable assembly process based on a wearable AR device.The system is applied to cable assembly on an aircraft bulkhead prototype.Results The results show that this system can recognize the number,types,and locations of brackets,and can correctly read the text of aircraft cables.The authoring tool can assist users who lack professional programming experience in establishing a process plan,i.e.,assembly outline based on AR for cable assembly.Conclusions The system can provide quick assembly guidance for aircraft cable with texts,images,and a 3 D model.It is beneficial for reducing the dependency on paper documents,labor intensity,and the error rate.展开更多
Microbial pesticides can prevent and control diseases and pests of crops, and has become one of the important measures to ensure food and environmental safety. However, the potential harm of microbial pesticides to hu...Microbial pesticides can prevent and control diseases and pests of crops, and has become one of the important measures to ensure food and environmental safety. However, the potential harm of microbial pesticides to humans and animals is a serious concern at home and abroad. In this paper, we have investigated the infectivity and pathogenicity of a representative of viral microbial pesticides, helicoverpa armigera nuclear polyhedrosis virus (HaNPV), by specific and highly sensitive polymerase chain reaction technology. The results show that HaNPV can be gradually cleared in a short time after getting into blood of experimental rats, and does not infect other tissues or organs of animals;also indicate that the test subjects are not infectious to experimental rats after intravenous injection of HaNPV. Our method has good specificity and repeatability, and could provide an important reference for establishment of infectivity and pathogenicity detection methods for viral microbial pesticides in future.展开更多
基金the Civil Airplane Technology Development Program(MJ-2017-G-70)Defense Industrial Technology Development Program(JCKY 2018601 C 011)the MIIT(Ministry of Industry and Information Technology)Key Laboratory of Smart Manufacturing for High-end Aerospace Products,and the Beijing Key Laboratory of Digital Design and Manufacturing.
文摘Background Assembly guided by paper documents is the most widespread type used in the process of aircraft cable assembly.This process is very complicated and requires assembly workers with high-level skills.The technologies of wearable Augmented Reality(AR)and portable visual inspection can be exploited to improve the efficiency and the quality of cable assembly.Methods In this study,we propose a smart assistance system for cable assembly that combines wearable AR with portable visual inspection.Specifically,a portable visual device based on binocular vision and deep learning is developed to realize fast detection and recognition of cable brackets that are installed on aircraft airframes.A Convolutional Neural Network(CNN)is then developed to read the texts on cables after images are acquired from the camera of the wearable AR device.An authoring tool that was developed to create and manage the assembly process is proposed to realize visual guidance of the cable assembly process based on a wearable AR device.The system is applied to cable assembly on an aircraft bulkhead prototype.Results The results show that this system can recognize the number,types,and locations of brackets,and can correctly read the text of aircraft cables.The authoring tool can assist users who lack professional programming experience in establishing a process plan,i.e.,assembly outline based on AR for cable assembly.Conclusions The system can provide quick assembly guidance for aircraft cable with texts,images,and a 3 D model.It is beneficial for reducing the dependency on paper documents,labor intensity,and the error rate.
文摘Microbial pesticides can prevent and control diseases and pests of crops, and has become one of the important measures to ensure food and environmental safety. However, the potential harm of microbial pesticides to humans and animals is a serious concern at home and abroad. In this paper, we have investigated the infectivity and pathogenicity of a representative of viral microbial pesticides, helicoverpa armigera nuclear polyhedrosis virus (HaNPV), by specific and highly sensitive polymerase chain reaction technology. The results show that HaNPV can be gradually cleared in a short time after getting into blood of experimental rats, and does not infect other tissues or organs of animals;also indicate that the test subjects are not infectious to experimental rats after intravenous injection of HaNPV. Our method has good specificity and repeatability, and could provide an important reference for establishment of infectivity and pathogenicity detection methods for viral microbial pesticides in future.
