Assembly Sequence Planning by Using Multiple Random Trees Based Motion Planning

2012 ◽  
Author(s):  
Carlos Morato ◽  
Krishnanand Kaipa ◽  
Satyandra K. Gupta
Keyword(s):  
Motion Planning ◽  
Assembly Sequence Planning ◽  
Random Trees ◽  
Planning System ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Disassembly Sequence Planning ◽  
Sequence Planning ◽  
Disassembly Sequence ◽  
Assembly Sequences

In this paper, we introduce multiple random trees based motion planning to perform assembly sequence planning for complex assemblies. Initially, given an assembly model, our technique performs disassembly sequence planning. This approach dynamically reduces the size and complexity of the assembly based on a hierarchical exploration structure that keeps information about the completion of the disassembly. Next, the disassembly information is used to generate feasible assembly sequences, along with precedence constraints, to assemble each part into the current subassembly. The motion planning system chooses part order by detecting geometrical interferences and analyzing feasible part movements. Results from tests on a variety of complex assemblies validate the efficiency of our approach.

scholarly journals Assembly Sequence Planning Using Artificial Neural Networks for Mechanical Parts Based on Selected Criteria

2021 ◽  
Vol 11 (21) ◽  
pp. 10414
Author(s):  
Marcin Suszyński ◽  
Katarzyna Peta
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Clustering Algorithm ◽  
Assembly Sequence Planning ◽  
Planning System ◽  
Assembly Sequence ◽  
Mechanical Parts ◽  
Sequence Planning ◽  
Assembly Sequences ◽  
Artificial Neural

The proposed model of the neural network describes the task of planning the assembly sequence on the basis of predicting the optimal assembly time of mechanical parts. In the proposed neural approach, the k-means clustering algorithm is used. In order to find the most effective network, 10,000 network models were made using various training methods, including the steepest descent method, the conjugate gradients method, and Broyden–Fletcher–Goldfarb–Shanno algorithm. Changes to network parameters also included the following activation functions: linear, logistic, tanh, exponential, and sine. The simulation results suggest that the neural predictor would be used as a predictor for the assembly sequence planning system. This paper discusses a new modeling scheme known as artificial neural networks, taking into account selected criteria for the evaluation of assembly sequences based on data that can be automatically downloaded from CAx systems.

scholarly journals Research Method of Assembly Sequence Planning Based on Assembly Constraint Relationship Analysis

2018 ◽  
Vol 237 ◽  
pp. 03005
Author(s):  
Yang Yi ◽  
Xiaojun Liu ◽  
Zhonghua Ni ◽  
Xia Tang ◽  
Xiaokang Xu
Keyword(s):  
Automatic Generation ◽  
Assembly Sequence Planning ◽  
Assembly Sequence ◽  
Constraint Matrix ◽  
Sequence Planning ◽  
Geometry Model ◽  
Relationship Analysis ◽  
Disassembly Sequence ◽  
Assembly Sequences ◽  
Definition Of

In order to effectively reduce the human-computer interaction (HCI) workload before the assembly process simulation in the digital assembly environment, and to enhance the intelligence of assembly sequence planning, we introduce the assembly constraint relationship into the automatic generation of assembly sequences and propose a practical assembly sequence planning method for intelligent assembly. Firstly, starting from the assembly geometry model, an assembly model liaison graph is constructed by combining the analysis of assembly constraint relationship and the definition of disassembly direction rules. Then, according to the liaison graph, disassembly priority constraint matrix based on constraint relationship is constructed, and the automatic generation and dynamic update of the disassembly priority diagram can be realized by the definition of disassembly doubly linked list. According to the diagram, the rationality of the disassembly sequence is determined through the interference check analysis, and then the assembly sequence is automatically generated from the reversed disassembly sequence. Finally, the method in the text is verified by an example case study.

Applications of Mating Conditions in Assembly Sequence Planning Task

1998 ◽  
Author(s):  
Pongsak Dulyapraphant ◽  
Tulga Ozsoy
Keyword(s):  
Degrees Of Freedom ◽  
Tolerance Analysis ◽  
Assembly Sequence Planning ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Kinematics Analysis ◽  
Sequence Planning ◽  
Planning Task ◽  
Intuitive Interface ◽  
Mating Conditions

Abstract Because of their intuitive interface, mating conditions have been prevalently used in assembly modelling. Besides their use for modelling purposes, other type of information, such as spatial relationships between parts and local degrees of freedom, can be directly derived from mating conditions. This information in turn can be used in various engineering analysis applications, such as kinematics analysis or automatic tolerance chain generation for tolerance analysis. In this paper, application of mating conditions in an assembly sequence-planning task is investigated. The proposed approach mainly engages the mating information represented in the CAD assembly model to automatically generate sequence plans based on the minimization of the number of assembly directions.

Assembly Modeling for 3D Component Based on Polychromatic Sets

2011 ◽  
Vol 411 ◽  
pp. 388-392 ◽  
Author(s):  
Yun Long Li ◽  
Jian Min Gao ◽  
Lei Shi ◽  
Song Wang
Keyword(s):  
Information Matrix ◽  
Spatial Location ◽  
Assembly Sequence Planning ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Assembly Modeling ◽  
Sequence Planning ◽  
Location Modeling ◽  
Dynamic Interference

In order to improve the efficiency of assembly modeling and provide a complete assembly model for assembly sequence planning (ASP), a method of assembly modeling based on polychromatic sets (PS) is proposed. Firstly, the assembly information of 3D Component is obtained by API function in SolidWorks. In addition, assembly incident matrix, information matrix and mapping matrix are built. On the basis of these matrixes, a method of location modeling is explored. The interference relation matrix is developed by judging the spatial location and analyzing dynamic interference relation among parts. Finally, a case study is given to verify the method.

A Dynamic Assembly Modeling Method for Satellite Final Assembly Sequence Planning

2010 ◽  
Vol 156-157 ◽  
pp. 332-338
Author(s):  
Yuan Zhang ◽  
Kai Fu Zhang ◽  
Jian Feng Yu ◽  
Lei Zhao
Keyword(s):  
Dynamic Model ◽  
Static Model ◽  
Modeling Method ◽  
Assembly Sequence Planning ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Final Assembly ◽  
Model Tree ◽  
Assembly Sequences ◽  
Dynamic Assembly

To study the effect of assembly process information combining disassemble and assemble on satellite assembly sequence, this paper presents an object-oriented and assembly information integrated model, which is composed of static model and dynamic model. The feasibility determination based on Cut-set theory is presented and the construction algorithm of dynamic model is established by static model, the dynamic assembly model tree is obtained by analyzing in layers and verifying possible states using this algorithm, where the assembly model tree includes all the geometric feasible assembly sequences of satellite. Finally, this modeling method is verified by a satellite product.

Research on Aircraft Assembly Sequence Planning Technology Based on Key Characteristics

2013 ◽  
Vol 328 ◽  
pp. 9-16 ◽  
Author(s):  
Zhan Lei Sun ◽  
Peng Fei Han ◽  
Gang Zhao
Keyword(s):  
Process Design ◽  
Assembly Sequence Planning ◽  
Assembly Process ◽  
Assembly Sequence ◽  
Assembly Quality ◽  
Constraint Matrix ◽  
Aircraft Assembly ◽  
Sequence Planning ◽  
Key Characteristics ◽  
Assembly Sequences

Assembly Sequence Planning (ASP) is an essential question for aircraft assembly process design. Modern aircraft assembly contains plenty of complex shape components, which have so many assembly features to ensure, this leads to a large number of feasible assembly sequences using traditional sequence planning algorithms; and it is hard to evaluate the contribution to assembly quality for every sequence. A methodology called Key Characteristics Based ASP is proposed in this paper, which can significantly reduce unavailable sequences and ensure key features for quality in assembly process designing compared with previous methods. The methodology focuses on the final assembly quality and considers it as Assembly Key Characteristics (AKCs) in the beginning of assembly process design. With tools such as AKCs decomposition, Datum Flow Chain, precedence constraint matrix, the methodology describes the main process for ASP. To verify the technologys effectiveness, this paper presents an application of the algorithm in an aircraft component assembly by an 863 program.

Petri Net Models for Assembly Sequences Planning

2007 ◽  
Vol 10-12 ◽  
pp. 411-415 ◽  
Author(s):  
Y.L. Fu ◽  
R. Li ◽  
H.B. Feng ◽  
Y.L. Ma
Keyword(s):  
Petri Net ◽  
Assembly Sequence Planning ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Assembly Operation ◽  
Knowledge Based ◽  
Assembly Sequences ◽  
Model Size ◽  
Assembly Sequences Planning ◽  
Optimal Assembly

Assembly sequences can be represented by a Petri net(PN) which characterizes dynamic system changes and provides a tool for obtaining optimal assembly sequences. In this study some assembly operation constraints are considered in order to obtain more practical sequences which are conformed to real situations. In order to enhancing the efficiency of the assembly sequence planning, knowledge-based Petri net, combining an usual Petri net with expert’s knowledge and experiences, is proposed to construct the assembly model. With the complexity of the product, the product’s assembly model size will be too large to analysis. So the basic subnets are used to reduce the large PN. And the reduced version can be used for the analysis of the original PN. To verify the validity and efficiency of the approach, a variety of assemblies including some complicated products from industry are tested, and the corresponding results are also presented.

The Two Phased Method of Hull Block Assembly Sequence Planning

2011 ◽  
Vol 421 ◽  
pp. 235-239
Author(s):  
Shi Peng Qu ◽  
Zu Hua Jiang
Keyword(s):  
Constraint Satisfaction ◽  
Constraint Satisfaction Problem ◽  
Assembly Sequence Planning ◽  
Assembly Process ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Hierarchical Assembly ◽  
Sequence Planning ◽  
Whole Process ◽  
Block Based

A hull block assembly sequence planning (ASP) problem is modeled as a constraint satisfaction problem where the precedence relations between operations are considered constraints. In order to generate the proper assembly sequence of the hull block, we analyzed the structure features of the block and built the hierarchical assembly model of the block. Based on this model, we divided the whole process of the block assembly into the small subassembly phase and the unit subassembly phase. There exists the rule that the assembly process of the subassembly in the same phase is similar, and it's different to the subassembly in the different phases. So, we proposed the different methods to plan the assembly sequence of the different phases. An example is given to illustrate that this two phased method can solves the block ASP problem effectively and accurately.

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