Assembly Process Planning Research Articles

Autonomous Assembly Process Planning According to the Production Line Configuration

In this study, a virtual production line is used to present a method for generating assembly process-relational plans for a product according to the configurations of the production line and verify the effectiveness of the proposed method. In an autonomous production system, process-relational plans are generated dynamically by agents based on process-relation graphs. Usually, such process-relation graphs are not determined uniquely and often have some degrees of freedom. Therefore, more practical and efficient assembly process-relational plans would be obtained if process-relation graphs were rewritten according to changes in the configurations of actual production lines. In the proposed method, process-relation graphs are rewritten dynamically by agents using two simple rewriting rules. The results from simulations on a virtual assembly line provided that the progress of the assembly job differs with the quantities of invested jobs and machine layouts. Accordingly, the simulation results prove the usefulness of rewriting process-relation graphs according to the configurations of actual shop floors.

Method for an Enhanced Assembly Planning Process with Systematic Virtual Reality Inclusion

The use of Virtual Reality (VR) technology is a promising approach to eliminate crucial problems in assembly planning.This approach presents an enhanced assembly planning process with valuable integrated VR assistance for a definite structured detection of planning failures. It integrates the VR validation of the assembly in a workshop after the specification step of the assembly planning process. Detailed holistic instructions for the workshop preparation and the VR use are given. This includes a data flow model, hardware requirements and the workshop team structure as well as testing the single assembly steps and the detection and evaluating of planning failures. Further, a procedure for improving those imperfections during the VR workshop is developed. Changes will be written back into the specifications book and the planning will be implemented in the physical factory. This leads to an enhanced detection and improvement of planning failures before the realization of a new assembly station.

Analysis and Control of Assembly Precision in Different Assembly Sequences

In the assembly process, the tolerance of mating parts or products, especially geometric tolerance, may cause geometric deviations in the assembly. These deviations must be kept in a reasonable range to ensure the precision and stability of assembly. The paper analyzes the influence caused by the difference in assembly sequences on the geometric deviation of key features in an assembly, which results in the influences on assembly precision. The research is done on an example model with two approaches: the mathematical method based on homogenous transformation matrix (HTM) and the simulation-based method. In the mathematical method, a transformation matrix is used to describe the geometric deviations of mating features caused by the tolerance and assembly clearance, and the resulting propagations in different assembly sequences. In the other method, the geometric deviations are measured with a CAT package based on the Monte-Carlo technique. Through the results of the methods, assembly precision could be identified and corresponding assembly sequences could be evaluated, which may serve as the evidence for the optimization assembly process planning.

Virtual Assembly of an Airplane Turbine Engine

This paper presents the virtual assembly of an airplane turbine engine and discusses the advantages of building virtual reality models in assembly process verification. The assembly parts and assembly sequence using a Virtual Reality Design system are explained. Virtual prototyping has come a long way in recent years, where current enviroments enable sterescopic visuals, surround sound, and ample interaction with generated models. In a virtual reality environment that is built with VR Software, the virtual prototype of a turbine engine is developed, and a simulation of movement of parts is conducted to illustrate assembly process planning.

Rapid Prototyping for Assembly Training and Validation

Rapid prototyping refers to a group of techniques that are used to fabricate a model of a physical part layer-by layer directly from a computer aided design file. It has been widely used in several domains to accelerate, check and validate product design, and implementation of product. However, little work has been dedicated to the use of rapid prototyping technology in manufacturing assembly validation and training. This paper presents guidelines for using rapid prototyping in manufacturing assembly. A case study is designed to validate the design and implementation of an assembly product made of subparts, and to validate the assembly and human operator training processes. Rapid prototyping technology is applied successfully for assembly process planning.

Geometric Enhanced Ontology Modeling for Assembly Process Planning

Geometric Enhanced Ontology Modeling for Assembly Process Planning

Studies on Techniques of Integrated House Assembly Simulation

This thesis introduces integrated house assembly simulation platform technology. It is divided into three categories: assembly simulation for the center with product design, assembly simulation for the center with assembly planning and assembly simulation for the center with virtual prototype. According to the characteristics of the integrated house assembly and modeling, it puts forward level assembly analysis method and studies the assembly system planning, assembly sequence planning and assembly path planning simulation technology. The results show that through the production system and assembly operation simulation technology research, it improves the rationality of the integrated house assembly process planning.

Assembly Process Planning Based on Tri-Dimensional Visual Platform

As the precision and quality requirements for assembly process is very high, with the features of security or irreversibility, assembly has become an key link of restricting the improvement of product quality and productivity for some industries such as automotive, aerospace and other industries. In this paper, based on the construction of the tri-dimensional visual platform, assembly process design process is studied, on the basis of tri-dimensional process model, the assembly process is simulated and analyzed in real-time, the assembly path and assembly interference check is implemented, thus shorten the planning and assembly debugging cycle greatly, improve the quality and efficiency of the process design.

Data Mining-supported Generation of Assembly Process Plans

The application and functional scope of digital assembly planning tools have been permanently increasing in order to deal with product and process complexity. Consequently a large amount of assembly-related data is stored in different systems alongside the product emergence process. By means of data mining techniques an intelligent utilization of this data can be accomplished for future assembly planning. This paper presents an approach for data mining-supported generation of assembly process plans to enhance planning efficiency. The approach is based on the classification and clustering of both product and process data as well as on the identification of their correlations.

Assembly Process Planning Method for Complex Electromechanical Products

Currently, neither the efficiency nor the effectiveness is sufficient in the area of the assemble optimization that commonly involves the genetic algorithm. A novel method to solve the cumbersome problem in the optimization of assembly sequences was proposed. On the basis of the assembly constraint matrix, the optimized assembly sequence is obtained with the proposed evaluating factors of the process requirement. That is the evolution of the original genetic algorithm to a certain extent. The effectiveness of the proposed method was proved by the comparison with the ant colony algorithm.

An intelligent interactive approach for assembly process planning based on hierarchical classification of parts

Assembly process planning is a difficult problem in the product design and development process. In order to reduce the difficulty of assembly process planning (APP), this paper presents an approach to finding a practical plan for assembly process through the intelligent interactive method based on hierarchical classification of parts. First, two hierarchical classification principles towards interactive disassembly are presented based on the key assembly constraint (KAC). Then, the initial assembly relationship of the product is readjusted to a new hierarchical structure which is more suitable for assembly planning according to a novel hierarchical classification algorithm. On the basis of the new hierarchy of product, an intelligent disassembly-based approach is presented, which not only takes full advantage of the ant colony algorithm for searching and constructing an initial assembly sequence with three available assembly principles, but also makes full use of the experience and knowledge of the human being for achieving a better assembly process. The intelligent disassembly approach can achieve an optimized assembly sequence, paths and scheme necessary information regarding the required assembly fixtures and tools. Finally, a case study shows that the proposed approach is feasible and practical.

Consensus tree method for generating master assembly sequence

An assembly process plan for a given product provides the sequence of assembly operations, their times as well as the required tools and fixtures for each operation. Much research has been done on automating and optimizing assembly sequence generation as the most important part of an assembly process plan. A novel method for generating the assembly sequence of a given product based on available assembly sequence data of similar products is presented. The proposed method uses a binary tree form to represent the assembly sequences of an existing family of products. A Genetic Algorithm is employed to find the consensus tree that represents the set of all assembly sequence trees with minimum total dissimilarity distance. This is similar to defining Generic Bill-of-Material. The generated consensus tree serves as a master assembly sequence for the product family. The assembly sequence for a new product variant that falls within, or significantly overlaps with, the scope of the considered family of products can be directly extracted from the derived master assembly sequence tree. The developed method is demonstrated using a family of three control valves. This novel method greatly simplifies and enhances automatic assembly sequence generation and minimizes subsequent modifications, hence, reduces assembly planning cost and improves productivity.

Interactive assembly simulation with haptic feedback

PurposeThe paper aims to present interactive simulation with haptic feedback as a valid method for solving complex assembly problems in the context of industrial product development. Its purpose is to clarify the position of interactive simulation with respect to other methods, and to emphasize its specific value for design engineers.Design/methodology/approachThe paper describes the challenges faced by design engineers in the context of design for assembly and assembly process planning. It introduces and compares automatic path planning and interactive simulation as two different approaches for checking the feasibility of assembly tasks. It provides a review of the scientific challenges and technical issues faced when implementing interactive simulation with haptic feedback in this context. It presents recent research results in the domains of final insertion and human model simulation.FindingsThe paper provides an overview of the scientific, technological and practical aspects of interactive simulation with haptic feedback. It explains how this method benefits from the manual skills and cognitive capabilities of the human operator for solving complex assembly problems. It proposes an assessment of the technical maturity using the Technology Readiness Level approach.Originality/valueThe paper gives insights about the maturity and usability of interactive assembly simulation with haptic feedback, for the benefit of design engineers seeking new ways to decrease product development time and costs while increasing quality.

Study in Virtual Assembly of Hull Block on DELMIA

The assembly process planning of hull block is an important point in the study of manufacturing automation and computer integrated manufacturing system (CIMS), which will influence the construction period and quality in shipbuilding negatively. Based on the assembly level model, this paper presents a new design of assembly process planning for hull block. With the improved disassembly method, we can get the reasonable planning of assembly sequence. At last, the whole assembly process was simulated based on DELMIA software. The results show that the study will be instructive and meaningful to the assembly of hull block.

Manufacturing Process Specification and Collaborative Decision-Making

A majority of information in manufacturing is the process information which presents mobility. Such information reflects transforming process form materials to products. This research establishes a manufacturing process information model that presents uniqueness, validness, completeness and generality based in PSL. The model can provide necessary process information and related product, material and resource information required by systems for integrating and collaborative decision making. It then enables to build a collaborative manufacturing decision making process model which is capable of utilizing the process information model. By defining logic procedure, data wrapping and service invoking in the decision making process model, multi-manufacturing systems collaborative decision making will be implemented. Such method of manufacturing process information modeling and decision making process modeling is illustrated by examples of the collaborative creation of a part process plan and an assembly process plan considering actual manufacturing environment.

Universal mechanism modeling method in virtual assembly environment

Motion simulation and performance analysis of mechanism are important methods for analyzing assembly quality after finishing assembly simulation in virtual assembly environment. However, most simulation systems have no function of mechanism motion simulation due to the randomicity of mechanism and lack of universal mechanism modeling method. In order to realize the simulation of any mechanism after finishing assembly simulation in a virtual environment, a new universal mechanism modeling method is presented. Two main models are contained in the mechanism model: information model and mathematical model. Firstly, the information model of mechanism is proposed to describe the data structure of mechanism which contains bottom geometry data, information of constraint, link, kinematic pair and physical data. Because the object of mechanism simulation is the assembly, which is assembled during the process of assembly simulation, the information of mechanism can be obtained automatically through mechanism automatic search method. Secondly, mathematical model of mechanism is presented. The mathematical model uses mathematical method to express the mechanism. In order to realize the automatic expression of any random mechanism, basic constraint library is presented, consequently random mechanism can be described based on the basic constraint library. Finally, two examples are introduced to validate the method in the prototype system named VAPP(Virtual Assembly Process Planning). The validation result shows that the mechanism modeling provides a universal modeling method for mechanism motion simulation in virtual assembly environment. This research has important effect on the development both of mechanism motion simulation and virtual assembly.

Computer Aided Generation the Assembly Process Files for Virtual Assembly

Computer Aided Assembly Process Planning is a method of automatically generating assembly process files with computer. This paper describes an integrated assembly process files generation system for virtual assembly. The objectives of this study are to integrate assembly planning of a product with its CAD model, generate a correct and practical assembly sequence and establish a software system to generate the assembly process files. The method of generating assembly process charts for virtual assmbly is researched. The system framework of generating assembly process charts is been set up. The assembly model information that needed for the assembly process charts generation is analyzed. The expression method of assembly sequence and arithmetic of generating assembly process charts is put forward. A speed reducer is used as an example to check the system.

Assembly Model Based on Dynamic Transition Graph for Satellite General Assembly Process Planning

Beginning with the disassembly of the semi-finished modules, the general assembly process of satellites is quite different from that of other mechanical products. This kind of disassembly-reassembly process cannot be solved by the widely used cut-set theory that only deals with linear problems, thus an approach called Dynamic Transition Graph (DTG) is proposed to solve this nonlinear assembly sequence planning problem. By analyzing and verifying possible assembly statuses hierarchically through matrix operations, a DTG is produced on the basis of Liaison Graph, where the DTG includes all the geometric feasible assembly sequences for the general assembly of satellite. Finally, the effectiveness of this method is verified by an example.

Tools and equipment modelling for interactive assembling operating in a virtual environment

Tools and equipment (T&E) play an important role in the simulation of virtual assembly, especially in the assembly process simulation and plan. The interactive operation simulation of T&E is also a challenge for interactive assembly operation because of variety in function and complexity in structure and manipulation. Based on detailed analysis of interactive operations, the functional requirement for T&E is given. Then, a unified modelling method for information expression and function realisation of general T&E is represented, and the handling methods of some typical manual, semi-automatic, automatic T&E are discussed. Finally, the rear suspension and the front suspension assembly workplace operation simulation in the RA-750 car assembly line are introduced. The result shows that the modelling and handling methods are applicable in the interactive simulation of various T&E.

The Research of Hierarchy Assembly Semantic Model Based on Intelligent Assembly Process Planning

Through analysis of Traditional CAD software modeling methods, combined with process planning requirements of intelligent virtual assembly, in the proposed semantic-based multi-level top-down model of virtual assembly. This paper proposes a semantic-based top-down model of multi-level virtual assembly.On this basis, the assembly semantic information extraction process is Focused analyzed, in the three-dimensional model data, non-geometric factors such as assorted features, assembly features, assembly engineering relations are extracted, and modeling is Established by Protégé ontology-based tool, the model is imported into the 3DVAPP(3D Virtual Assembly Process Planning) system to be verified, and Finally this paper implementated the assembly process planning applications such as intelligent parts identification, Provide a theoretical and practical basis for intelligent virtual assembly.