Filippova Automated planning of graduality assembly

2021 ◽  
pp. 28-44
Author(s):  
D. Proskurenko ◽  
◽  
O. Tretyak ◽  
M. Demchenko ◽  
M. Filippova ◽  
...  

Modern industrial production requires the improvement of assembly processes, and thus increase the level of automated intelligent sequence planning. Therefore, researches in the field of automation of the sequence of assembly of products in industries are relevant at this time. In today's world there is a need to develop complex, accurate products. Problems are created in industries due to the reduction of the life cycle of products. There is a need to study the problem of assembly planning to achieve the goal of practical implementation and standardization of assembly plans. Creating graphs of the addition process is one of the problems. The assembly planning system can reduce human intervention in the process and reduce computational effort. The finished assembly contains many components that can be assembled using many sequences. A review of the methods from the literature showed that although these methods increase the automation level, they still cannot be applied to actual production because they do not take into account the experience and knowledge that can play a major role in planning and are of great value. Assembly planning, relationship charts, priority charts. Improving the assembly planning system to create a communication schedule and an assembly priority schedule was proposed. The advanced system will be used to generate possible assembly sequences with subassembly identification. A system has been developed to create alternative possible assembly sequences that can be used by component part / product designers in the early stages. A system capable of generating assembly sequences for simultaneous assembly of multiple parts has been proposed. Conclusions and work results can be applied used and improved for more productive product development by designers in the early stages and faster assembly of products in enterprises. The paper did not consider practical limitations (gravity) and irreversible assembly operations, such as permanent fastening, welding etc. Кey words: assembly, blocking graph, relation graph, sequence

1997 ◽  
Vol 06 (02) ◽  
pp. 149-163 ◽  
Author(s):  
F. Röhrdanz ◽  
H. Mosemann ◽  
F. M. Wahl

In this paper we present our high level assembly planning system HighLAP·HighLAP generates and evaluates all assembly sequences of a mechanical assembly with minimal user interaction. For the evaluation of all feasible assembly sequences several criteria are taken into account. HighLAP considers for example the separability and the manipulability of the generated (sub)assemblies. Furthermore, the necessity of reorientation for a mating operation and parallelism during plan execution is considered. Another important criterion is the stability of the generated (sub)assemblies. Most of the assembly planners developed up to date use heuristics or user defined criteria to determine assembly stability for plan evaluation. In order to bring automatic assembly planning closer to reality HighLAP performs a powerful geometrical and physical reasoning. The presented system is the first assembly planning system taking into account the range of all stable orientations of an assembly considering friction for plan evaluation.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Özkan Özmen ◽  
Turgay Batbat ◽  
Tolgan Özen ◽  
Cem Sinanoğlu ◽  
Ayşegül Güven

Assembly refers both to the process of combining parts to create a structure and to the product resulting therefrom. The complexity of this process increases with the number of pieces in the assembly. This paper presents the assembly planning system design (APSD) program, a computer program developed based on a matrix-based approach and the discrete artificial bee colony (DABC) algorithm, which determines the optimum assembly sequence among numerous feasible assembly sequences (FAS). Specifically, the assembly sequences of three-dimensional (3D) parts prepared in the computer-aided design (CAD) software AutoCAD are first coded using the matrix-based methodology and the resulting FAS are assessed and the optimum assembly sequence is selected according to the assembly time optimisation criterion using DABC. The results of comparison of the performance of the proposed method with other methods proposed in the literature verify its superiority in finding the sequence with the lowest overall time. Further, examination of the results of application of APSD to assemblies consisting of parts in different numbers and shapes shows that it can select the optimum sequence from among hundreds of FAS.


Author(s):  
Ata A. Eftekharian ◽  
Ranjith Poladi ◽  
Matthew I. Campbell

In order to build a comprehensive automated assembly planning tool, three important tasks must be accomplished: generating feasible assembly sequences, evaluating the quality of a sequence, and the search method for finding the optimal plan. This paper describes a novel approach to the latter two. The evaluation approach combines empirical data and geometric reasoning techniques to arrive at estimates of assembly time for any generic assembly model. The evaluation is constantly invoked from a tree-search method that only searches amongst valid assembly operations. The algorithm has been tested on a variety of examples ranging from simple to complex assemblies.


Author(s):  
A. N. Bozhko

Computer-aided design of assembly processes (Computer aided assembly planning, CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. Intensive research on CAAP has been underway since the 1980s. Meanwhile, specialized design systems were created to provide synthesis of assembly plans and product decompositions into assembly units. Such systems as ASPE, RAPID, XAP / 1, FLAPS, Archimedes, PRELEIDES, HAP, etc. can be given, as an example. These experimental developments did not get widespread use in industry, since they are based on the models of products with limited adequacy and require an expert’s active involvement in preparing initial information. The design tools for the state-of-the-art full-featured CAD/CAM systems (Siemens NX, Dassault CATIA and PTC Creo Elements / Pro), which are designed to provide CAAP, mainly take into account the geometric constraints that the design imposes on design solutions. These systems often synthesize technologically incorrect assembly sequences in which known technological heuristics are violated, for example orderliness in accuracy, consistency with the system of dimension chains, etc.An AssemBL software application package has been developed for a structured analysis of products and a synthesis of assembly plans and decompositions. The AssemBL uses a hyper-graph model of a product that correctly describes coherent and sequential assembly operations and processes. In terms of the hyper-graph model, an assembly operation is described as shrinkage of edge, an assembly plan is a sequence of shrinkages that converts a hyper-graph into the point, and a decomposition of product into assembly units is a hyper-graph partition into sub-graphs.The AssemBL solves the problem of minimizing the number of direct checks for geometric solvability when assembling complex products. This task is posed as a plus-sum two-person game of bicoloured brushing of an ordered set. In the paradigm of this model, the brushing operation is to check a certain structured fragment for solvability by collision detection methods. A rational brushing strategy minimizes the number of such checks.The package is integrated into the Siemens NX 10.0 computer-aided design system. This solution allowed us to combine specialized AssemBL tools with a developed toolkit of one of the most powerful and popular integrated CAD/CAM /CAE systems.


2021 ◽  
Vol 11 (21) ◽  
pp. 10414
Author(s):  
Marcin Suszyński ◽  
Katarzyna Peta

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.


Author(s):  
Andres Rivero ◽  
Ehud Kroll

Abstract The original exploded view method of assembly planning (Mohammad and Kroll, 1993b) attempts to automatically generate the “simplest” assembly plan for a product. Criteria for optimal assembly sequences, however, are sometimes unclear and dependent on specific circumstances. It may therefore be advantageous to present the designer with more than one solution to the assembly planning problem, or allow him or her to select the appropriate criteria. This paper introduces an extension to the original method, where all possible assembly sequences are generated. This completely automatic capability is demonstrated by manually applying the method to a simple example and then comparing the results to those generated by the algorithmic procedure of the C. S. Draper Lab.


Author(s):  
R. Mantripragada ◽  
D. E. Whitney

Abstract In order to be able to lay out, analyze, outsource, assemble, and debug complex assemblies, we need ways to capture their fundamental structure in a top-down design process, including the designer’s strategy for kinematically constraining and locating the parts accurately with respect to each other. We describe a concept called the “Datum Flow Chain” to capture this logic. The DFC relates the datum logic explicitly to the product’s key characteristics, assembly sequences, and choice of mating features, and provides the information needed for tolerance analyses. Two types of assemblies are addressed: Type-1 where the assembly process puts parts together at their prefabricated mating features, and Type-2 where the assembly process can incorporate in-process adjustments to redistribute variation. Two types of assembly joints are defined: mates that pass dimensional constraint from part to part, and contacts that merely provide support. The scope of DFC in assembly planning is presented using several examples. Analysis tools to evaluate different DFCs and select the ones of interest are also presented.


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