Disassembly Sequence Generation Research Articles

Disassembly task planning for end-of-life automotive traction batteries based on ontology and partial destructive rules

Disassembly is an essential step for the cascade utilization of end-of-life automobile power batteries. The diversity in types and structures of end-of-life automobile power batteries has led to much waste in time and cost in manual disassembly processes. With the incoming large-scale retirement of automobile power batteries, it is urgent to use artificial intelligence technology to enable the automation of battery disassembly planning. In order to establish a complete and open product information model to realize the automatic disassembly task planning of end-of-life automobile power battery, a disassembly task planning method of automobile power batteries is proposed based on ontology and partial destructive rules. This presented approach is in combination with case-based reasoning/rule-based reasoning, which is utilized as the mechanism for disassembly knowledge reuse and reasoning. Firstly, a disassembly information ontology of automobile power batteries is constructed to describe the components information and assembly relation. Then, a set of partial destructive rules are formulated to guide the dismount of parts with destructive connection. Thirdly, a disassembly sequence generation method is presented to infer feasible planning schemes from the rule base. Finally, the effectiveness of the method is tested with a case study of a power lithium-ion battery pack. The case study has indicated that this presented method can generate the disassembly task schemes quickly and effectively, when applied to the disassembly of large-scale heterogeneous automobile power batteries.

Optimal disassembly sequence generation and disposal of parts using stability graph cut-set method for End of Life product

Optimal disassembly sequence generation and disposal of parts using stability graph cut-set method for End of Life product

A Disassembly Sequence Planning Method With Team-Based Genetic Algorithm for Equipment Maintenance in Hydropower Station

Disassembly sequence planning (DSP) is an important part of equipment maintenance in a hydropower station. In this paper, the generation of an excellent disassembly sequence (DS) for equipment is studied. Firstly, according to the characteristics of hydropower equipment, a combination node type is added to the directed graph analysis model, and the distance factor of components in space is added to the evaluation function of DS. Secondly, a DSP strategy including the grouping and minimization of the node's scope is adopted to reduce computational complexity. Thirdly, a novel team-based genetic algorithm (TBGA) combining teams, fast feasible solution generator (FFSG), precedence preservative crossover (PPX) mechanism, multi-point heuristic mutation (MHM) mechanism, and forward-and-backward optimization operator (FBOO) is designed for DSP. The proposed TBGA maintains global search capabilities through teams and enhances local search capabilities through individuals. In the evolutionary process, teams, MHM, and FBOO have good complementarity to improve the comprehensive performance of the algorithm. Finally, four experiments are conducted and the performance of TBGA is tested based on the comparison of a well-known genetic algorithm, simplified teaching-learning-based optimization, and simplified swarm optimization algorithm. The results show that the proposed method can get better search results in limited iterations and require only about 25% time of other algorithms.

Near Optimal Disassembly Sequence Generation for Large Equipment in Nuclear Plant

Near Optimal Disassembly Sequence Generation for Large Equipment in Nuclear Plant

Energy Efficient Disassembly Sequence Generation Using Subassembly Detection Method with Environmental and Economic Parts Selection

Supply chains have been more serious for environmental issues for not only the reduction of CO2 emission but also for material starvation. To enhance a closed loop supply chain for assembled product, a disassembly system is required. At end-of-life, the assembly products at recycling organization should be disassembled environmentally and economically for not only low carbonization but also of material circulation. This recycling and reusing of product enables to reduce CO2 release because the virgin materials which release CO2 volumes caused by production and logistics can be saved by the usage of the recovered materials. Parts with higher recycling and CO2 saving rates ought to be chosen and physically disassembled, but the manual disassembly brings a higher cost, rather than discarding the parts. Therefore, material recovery value is also to be considered for parts selection during the assembly operation. Parts information like material recovery value, CO2 release, weight, precedence relationships are required for environmental and economic parts selection. This study proposes a CAD based approach for environmental and economic parts selection for disassembly using solid works sustainability. It considers higher CO2 saving rate, higher recycling rate and higher material recovery value as environmental and economic criteria for parts selection.

Time-based disassembly method: how to assess the best disassembly sequence and time of target components in complex products

Circular economy (CE) is a new business model that is pressing manufacturing companies to think about closed loop scenarios for materials and products. Design for End-of-Life (DfEoL) and Design for Disassembly (DfD) are key enabling methods for the effective application of this model. The paper presents a time-based method for the calculation of disassembly sequences, adopting basic theories and techniques in this topic and integrating new concepts for the assessment of the disassembly time. The method consists of five steps and starts from the documentations (e.g., CAD model) generally available early in the product development process. The first three steps encompass the product analysis by including (i) the definition of target components from the general assembly, (ii) the analyses of the virtual model, and (iii) the assessment of the so-called level matrix, which is based on the concept of disassembly levels and liaisons characterization among components. The last two steps allow for the assessment of the time-based disassembly sequence by including (iv) the analysis of feasible sequences and (v) the generation of the best disassembly sequence for target components. The method mainly overcomes two issues highlighted in the literature regarding the reliability of the disassemblability analysis using a time-based approach and the quality of results accounting for the real condition of the product at the time of disassembly. The calculation of the effective disassembly time is grounded on a specific repository developed to gather knowledge about the disassembly tasks and related disassembly time. This is the main contribution and novelty of the proposed approach. By using the proposed method, different target components of a washing machine are analysed with the aim of demonstrating the robustness of the method and its consistency in the estimation of disassembly time. A maximum deviation of 10% between the estimated and measured disassembly times is noticed.

Approaches and Challenges in Product Disassembly Planning for Sustainability

Due to the vast variety of products and end-of-life uncertainties of used products, product disassembly remains as a challenging research area. This paper aims to address the gap between sustainable product development and product life cycle through optimizing disassembly in each stage of the product life cycle. Firstly, a comprehensive review on design concepts for product development and relevant disassembly planning methodologies at the different phases of a product life cycle, such as Design for Disassembly (DfD), product service system (PSS), disassembly sequence generation (DSG), and reconfigurable disassembly systems (RDS) is presented. Next, a conceptual framework that leverages on emerging technology driven by Industry 4.0 and product family approach to facilitate product disassembly planning for sustainability is proposed. Lastly, a short summary on different challenges presented as well as the respective future work are elaborated.

Model of mobility state of parts: The automation of feasibility test in disassembly sequence generation

Disassembly sequencing is a concurrent research subject in design for life-cycle. Many past and recent researches are made to give practical methods for disassembly sequencing. The problem of assembly information’s modeling is one of the important sub-problems of disassembly simulation. The problem includes connection determination, disassembly direction identification, and part mobility state definition. In the present paper, the authors propose a new representation model of disassembly directions, starting from geometric and assembly data of computer aid design models. This model is based on a mobility matrix definition for every part. This matrix is also called disassembly direction matrix. The model gives information about the mobility state of a part during disassembly sequencing by updating its mobility matrix. Mobility state data are used in a practical computing of disassembly sequence feasibility. In this paper, theoretical explication of this modeling is given and validated by computational results. In the validation section, the model is applied to a computer aid design mechanism using a selective disassembly.

RFID-based integrated method for electromechanical products disassembly decision-making

Proper recovery of electromechanical products can prevent pollution, improve materials recycling rate and make economic benefits as well. However, a major obstacle is that the product lifecycle information essential for the recovery decision-making is difficult to be collected. This article shows how radio frequency identification (RFID) can be utilised to record and trace the lifecycle information, hence optimising disassembly process and improving recovery efficiency. The key factors of the integrated method are demonstrated: (1) an assembly–disassembly model is constructed purposefully due to characteristics of RFID; (2) a flexible encoding and storage approach using XML format is proposed uniquely for a universal usage of the limited memory space in RFID tags; and (3) a detailed iteration process for the automatic generation of a near-optimum disassembly sequence is illustrated. In addition, a set of related application programmes are developed, and the whole integrated method is verified by a case study. This integrated method is highly extensible, and it can be applied to various types of electromechanical products.

Virtual Disassembly Sequences Generation and Evaluation

First this paper presents a method for generating selective disassembly sequences. The method is based on the Lowest levels of a disassembly product graph. Instead of considering the geometric constraints for each pair of components, the proposed method considers the geometric contact and collision relationships among the components in order to generate the so-called Disassembly Geometry Contacting Graph (DGCG). The latter is then used for disassembly sequence generation thus allowing the number of possible sequences to be reduced by ignoring the components which are unrelated to the target. A simulation framework was developed and integrated in a Virtual reality environment (VRE) thus allowing generating the minimum number of possible disassembly sequences. Secondly, a method for disassembly operation evaluation by 3D geometric removability analysis in a VRE is proposed. It is based on seven new criteria divided into two categories: i). for ergonomic evaluation, ii). and for traditional processing evaluation. All criteria are presented by dimensionless coefficients automatically calculated, thus allowing evaluating disassembly sequences complexity. For this purpose, a Virtual Reality disassembly environment (VRDE) is developed based on Python programming language, utilizing mixed VTK (Visualization Toolkit) and ODE (Open Dynamics Engine) libraries. The framework is based on STEP, WRL and STL exchange formats. The analysis results and findings demonstrate the feasibility of the proposed approach thus providing significant assistance for the evaluation of disassembly sequences during Product Development Process (PDP).

Selective disassembly sequence generation based on lowest level disassembly graph method

Integration of disassembly operations during product design is an important issue today. As known, the number of possible disassembly sequences increases significantly with the number of parts in a product. Thus, generating proper disassembly sequences is critical. Most existing methods often require tremendous computational resources, while, at the same time, they often fail to find realistic and optimal solutions for complex product disassembly. For selective disassembly, for instance, it is important to eliminate the components which are unrelated with the target prior to sequence generation. In order to address this configuration, this paper deals with a method for generating the feasible disassembly sequences for selective disassembly. It is based on the lowest levels of a disassembly product graph. Instead of considering the geometric constraints for each pair of components, the proposed method considers the geometric contact and collision relationships among the components in order to generate the proposed disassembly geometry contacting graph (DGCG). The generation of the disassembly sequences is based on the investigated three cases called micro-units, which consider all the possible situations of relationships among the components in the DGCG. The latter is then used for disassembly sequence generation, thus allowing decreasing the number of possible disassembly sequences. For this purpose, a mixed Virtual Reality Disassembly Environment (VRDE) is developed based on Python programming language using mixed Visualization Toolkit (VTK) and Open Dynamics Engine (ODE) libraries. It is applied for automatic generation of the selective disassembly sequences and is illustrated within two examples.

Generating complete disassembly sequences by utilising two-dimensional views

This research work proposes a novel method to generate the complete disassembly sequences for mechanical products by utilising the part interference matrix which contains the removal directions of the parts and the part connection graph which indicates the contact among the parts in the assembly. Contrary to the earlier methods, the proposed method considers the two-dimensional views generated from the computer-aided design assembly model for automatically identifying the part removal directions and for generating the part connection graph. Rules are formulated in the proposed method to identify the part removal directions effectively and also to reduce the size of part connection graph, since the method of identifying the part removal directions and the size of the formulated graph plays a vital role in the generation of disassembly sequence. Finally, a heuristic method is developed to generate the best feasible disassembly sequences. The effectiveness of the approach is illustrated with three examples.

Computer-aided design assessment of products for end of life separation and material handling

A methodology is presented for the estimation of recyclability indicators of product designs. It combines an automated CAD-integrated disassembly sequence generation algorithm and a recyclability assessment module. The algorithm employs collision detection and CAD feature recognition for the extraction of disassembly tiers and sequences of specific components. This information together with the components’ characteristics, including materials, is then processed by the corresponding module, which is capable of providing an initial evaluation about the product's recyclability. The methodology is demonstrated through an industrial case study, involving rear axle designs that are associated to different truck models.

Two-stage Sequence Generation for Partial Disassembly of Products with Sequence Dependent Task Times

For disassembly sequence generation, partial disassembly and sequence dependent task times are typically not considered together in the same model. We developed a two-stage optimization program that first determines the optimal partial disassembly sequence according to reuse value only, followed by the second stage that finds the optimal partial disassembly sequence that also includes sequence dependence task times. We prove the optimality of the two-stage approach under the condition that all components with any positive reuse value must be included in the final sequence. If this condition does not need to be met, a task hedging policy is shown to be effective.

Disassembly information model incorporating dynamic capabilities for disassembly sequence generation

Abstract Industrial recycling and reusing is becoming more and more important due to the environmental and economic pressures. It involves disassembly activities to retrieve all the parts or selected parts. An information modeling for the disassembly and optimal disassembly sequence generation based on the information model becomes critical. Unlike the traditional graph based representation of product structure, this paper introduces an efficient and machine readable disassembly information model and then discusses a linear programming based optimization model for obtaining the optimal disassembly sequence from the proposed disassembly information model. A key feature of this approach is the incorporation and use of dynamic capabilities in its information model processing technique. Dynamic capabilities are added into the information model to handle state-dependent information such as parts' disassembly directions which may change after each disassembly operation. The overall information model is built in UML, and dynamic capabilities are represented as events in UML. The proposed method has been illustrated using an electrical–mechanical device.

A New Disassembly Network Graph Model and its Automatic Generation

Disassembly process model plays an important role in the generation of disassembly sequences and evaluation of disassembly process.Based on the concept of adjacency matrix and disassembly precedence matrix, combined with the related definitions of constraint nodes, such as, actual constraint node etc. A new disassembly network graph model is introduced, which can express the constrain information between parts, the priority of the constraints and and/or logical relationship between parts. In addition, according to the storage type and VC tool, its automatic generation model is obtained.

Quantitative Evaluation Method of Product Disassembly Based on Parts Failure Rate and Disassembly Time

In view of the fact that product disassembly efficiency is not taken into consideration in the traditional method based on experts' experience,a new quantitative evaluation method of product disassembly is herein presented based on parts failure rate and its disassembly time.Product information model with respect to its disassembly constraint graph is established on the basis of graph theory thought and object-oriented technology.Through developing the procedures of product disassembly sequence generation and optimization,parts disassembly process is simulated and a method of determining the basic disassembly time of product parts is proposed on the basis of modular arrangement of predetermined time standard(MODAPTS).By introducing part failure rate weight,basic disassembly time is converted to relative disassembly time and a calculation model of product disassembly efficiency is established on the basis of parts failure rate and its disassembly time so that the quantitative analysis and evaluation of product disassembly is implemented.The calculation method and its evaluation steps of product disassembly efficiency are demonstrated by combining with one example.Furthermore,the example shows that this quantitative evaluation method is reasonable,feasible,and able to optimize product disassembly design,thus having good engineering application value.

Research on Module Partition Strategy of Optional Disassembly

Optional disassembly could fulfill the process that parts remove from assembly, which is useful for product maintain, discarding and recycle. Total disassembly planning algorithm can be obtained through proper analysis and evaluation, however that is a difficult process. It is hard to obtain optimal solutions when a huge number of parts are to be removed from an assembly. Exponential explosion during the process of disassembly sequence generation has become a bottleneck for a long time due to over large number of parts included in the product. To solve this problem, an approach based on the modulization is proposed in the paper to generate the disassembly sequence. To partition modules of manufacture equipments, the module identifying method based on multi-rule decision can effectively solve the explosive problem. This method deals with the restrictions and limits of parts before disassembly, hence making disassembly more like the situation of the fact which is limiting the quantity of disassembly combinations, enhancing the efficiency of disassembly and making disassembly much easier.

Optimal disassembly sequence generation using a genetic programming

Efficient material reutilization is a rational way to facilitate sustainable technology because it can promote conservation of resources and energy while decreasing the environmental loads at the same time. Recycling and remanufacturing are particularly important and involve product disassembly to retrieve the desired parts and/or subassemblies. To facilitate such a perspective in this paper, we have developed a prototype system supporting strategic decision-making on disassembly for recycling at the design stage of the product life cycle. Based on the information given at the design stage, it decides automatically the optimal disassembly sequence through a metaheuristic method known as Genetic Programming, and evaluates the disassembly plan quantitatively. Its implementation takes place by using Java programming language, and illustrative examples are provided to show validity of the system.

Disassembly sequence generation in recycling based on parts accessibility and end-of-life strategy

Nowadays, global sustainability is the central issue in recycling and, increasingly, in manufacturing. Recycling used products can save energy, natural resources, and landfill space, and can reduce air pollution. It can give used products new lives. The study of disassembly is needed in order to make recycling economical, and disassembly sequence generation (DSG) plays an important role. An appropriate disassembly process plan can minimize the cost spent on the disassembly processes and maximize the benefits coming from the reused components. In the current paper, a new approach using Petri net modelling to generate an optimal disassembly sequence (ODS), based on accessibility and end-of-life (EOL) strategy, is described. The different life spans of the reusable components affect the disassembly order, especially in destructive disassembly, and the influence of components with different life spans on DSG is analysed. First, AND/OR graphs are used to generate all feasible disassembly sequences, and then AND/OR graphs are transferred into Petri net graphs while accessibility values and life span values of components are taken into account to obtain the ODS. A program using Microsoft C++ is developed to generate the ODS. The disassembly of a C-clamp is used as a trial example.