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1 – 10 of over 45000Li Shaochen, Zhenyu Liu, Yu Huang, Daxin Liu, Guifang Duan and Jianrong Tan
Assembly action recognition plays an important role in assembly process monitoring and human-robot collaborative assembly. Previous works overlook the interaction relationship…
Abstract
Purpose
Assembly action recognition plays an important role in assembly process monitoring and human-robot collaborative assembly. Previous works overlook the interaction relationship between hands and operated objects and lack the modeling of subtle hand motions, which leads to a decline in accuracy for fine-grained action recognition. This paper aims to model the hand-object interactions and hand movements to realize high-accuracy assembly action recognition.
Design/methodology/approach
In this paper, a novel multi-stream hand-object interaction network (MHOINet) is proposed for assembly action recognition. To learn the hand-object interaction relationship in assembly sequence, an interaction modeling network (IMN) comprising both geometric and visual modeling is exploited in the interaction stream. The former captures the spatial location relation of hand and interacted parts/tools according to their detected bounding boxes, and the latter focuses on mining the visual context of hand and object at pixel level through a position attention model. To model the hand movements, a temporal enhancement module (TEM) with multiple convolution kernels is developed in the hand stream, which captures the temporal dependences of hand sequences in short and long ranges. Finally, assembly action prediction is accomplished by merging the outputs of different streams through a weighted score-level fusion. A robotic arm component assembly dataset is created to evaluate the effectiveness of the proposed method.
Findings
The method can achieve the recognition accuracy of 97.31% and 95.32% for coarse and fine assembly actions, which outperforms other comparative methods. Experiments on human-robot collaboration prove that our method can be applied to industrial production.
Originality/value
The author proposes a novel framework for assembly action recognition, which simultaneously leverages the features of hands, objects and hand-object interactions. The TEM enhances the representation of dynamics of hands and facilitates the recognition of assembly actions with various time spans. The IMN learns the semantic information from hand-object interactions, which is significant for distinguishing fine assembly actions.
Details
Keywords
This study seeks to present a simple assembly line design and its balance for a low‐volume manufacturing company.
Abstract
Purpose
This study seeks to present a simple assembly line design and its balance for a low‐volume manufacturing company.
Design/methodology/approach
The study presents experiences with the design and implementation of a simple assembly line. The implementation concerns three aspects; design and construction of the assembly line, the assembly analysis of the product, and then balancing of the line. It also discusses construction and implementation difficulties of this tactical tool in the case company.
Findings
The study presents some outcomes from the design, implementation, and balancing of an assembly line for SMEs.
Research limitations/implications
The study is limited by the case company and its experience.
Practical implications
This study is not pure theoretical study, it has application stages for industry, and it provides some real interface for the people from SMEs.
Originality/value
The approach has an original value in respect of implementation of assembly line for a small manufacturing company which has many limitations.
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Keywords
A paper presented at the Paris Assembly Automation conference dealt with a typical project concerning assembly automation of an LPG gas valve which had not been designed for…
Abstract
A paper presented at the Paris Assembly Automation conference dealt with a typical project concerning assembly automation of an LPG gas valve which had not been designed for automatic assembly. A series of suggestions for design modifications were proposed with the purpose of simplifying assembly.
Mozafar Saadat, Roy Sim and Farid Najafi
This paper aims to present a method for predicting dimensional variation in assembly processes of a wingbox structure concentrating on the assembly of skin panels to rib feet.
Abstract
Purpose
This paper aims to present a method for predicting dimensional variation in assembly processes of a wingbox structure concentrating on the assembly of skin panels to rib feet.
Design/methodology/approach
Finite element modelling and experimental tests are conducted on the rib structure based on the site measurement gathered from the Airbus assembly factory.
Findings
The results have shown that the simulated model has the capability of predicting to an acceptable degree of accuracy the overall geometrical variations of the ribs and skin panels, as well as the positional variations of each individual rib foot.
Originality/value
The authors believe that no previous research has offered a similar prediction method for large aerostructures.
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THE increasing pressure of national and international competition is forcing firms to rationalise even further, especially in the field of assembly. In order to perform assembly…
Abstract
THE increasing pressure of national and international competition is forcing firms to rationalise even further, especially in the field of assembly. In order to perform assembly tasks with the least possible expenditure of time, assembly facilities, space requirements and personnel, it has become necessary to include these objectives in the development stage of the product. Therefore, assembly‐oriented design now provides a good opportunity for rationalisation.
Peter Gröndahl and Mauro Onori
The Assembly Systems Unit at the Royal Institute of Technology and IVF Stockholm has developed several Flexible Automatic Assembly (FAA) cell solutions over the years (Mark I…
Abstract
The Assembly Systems Unit at the Royal Institute of Technology and IVF Stockholm has developed several Flexible Automatic Assembly (FAA) cell solutions over the years (Mark I, Mark II, Mark IIF and Mark III). The industrial reality, however, clearly points out that the basic notions of flexibility must be extended and be enhanced without increasing the complexity. This has led our research team to revise the ideas and solutions available for manual and automatic assembly, resulting in the Hyper Flexible Automatic Assembly (HFAA) project. The paper describes the driving factors behind the needs and objectives for the HFAA project, as well as how it will present a standardised set of assembly process‐oriented system components. The paper also describes the new Mark IV application. This industrial HFAA system is being developed in order to test the concept’s industrial viability. The HFAA concept will allow the user to start from a manual assembly station and gradually add assembly equipment. The basic concepts of stepwise automation, standard assembly machine and sub‐batch principle emanate from our previous research.
Market turbulence forces assembly plants to constantly adjust their production volume of products, variants and quantities. At the same time, assembly plant managers must protect…
Abstract
Market turbulence forces assembly plants to constantly adjust their production volume of products, variants and quantities. At the same time, assembly plant managers must protect long‐term investments in the flexible assembly system. For reconfigurability and agility the best solution is the modular semi‐automatic approach by combining flexible automation and human skills. It gives managers possibility to adjust volume by adding new modules or to automate the manual tasks step by step. The control of material handling and information flow in the agile assembly system is important. To keep flexibility, the combination of an intelligent pallet, i.e. use of escort memory, carrying a single product together with other hardware providing paperless production even supports a lot size of one. The article shows how to create flexible capability and capacity in the final assembly systems.
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B. Gondocs and T. Kovacs
To improve the flexibility of its assembly methods the Bakony Works in Hungary took out a manufacturing licence with Bosch. Some examples of where the system has been used are…
The dividing line between the sensible and efficient use of assembly robots and that of dedicated automatic assembly machines requires detailed planning.
As competition grows in the robot field and as more sophisticated applications emerge, it has become necessary to accurately predict robot cycle time. Especially in the area of…
Abstract
As competition grows in the robot field and as more sophisticated applications emerge, it has become necessary to accurately predict robot cycle time. Especially in the area of robot assembly applications, it is necessary to estimate times to balance multi‐arm systems and to economically compare robot assembly systems to alternate methods. Using the Unimate 6000 robot system as a model and manual time methods as a guide, a robot time and motion method is developed. Three time estimating methods are discussed starting with a simple, approximate one and finishing with a detailed, accurate one. All three methods can be adapted for use with applications other than assembly and will be further evaluated in the future with other robot systems.