Polychromatic Sets Research Articles

Process information optimization method based on process constituent elements model and polychromatic set theory

This research presents a novel model for optimizing process information in manufacturing steps through the utilization of Process Constituent Elements (PCE), with the aim of enhancing the effectiveness of product process information design. To achieve this objective, a systematic analysis is conducted on six dimensions: input, output, resources, value-adding activities, environment, and process control and inspection content. In addition, specific attributes of PCE are investigated, and an improved FP-growth algorithm is employed to extract the optimized structural expressions of typical PCE, thus determining specific expression requirements. The PCE and their attribute relationships are organized into modular mapping rules, resulting in an optimized representation structure based on a polychromatic set approach. The effectiveness of this approach is quantitatively assessed by developing a comprehensive quality indicator evaluation system for process information and using a fuzzy comprehensive evaluation model for analysis.

Digital twin and parameter correlation-enabled variant design of production lines

ABSTRACT The rapid transformation of production lines into a new design scheme is the key to improving the market competitiveness of enterprises. The production line is a complex manufacturing system with a complex structure. There are multidisciplinary correlation networks between different design dimensions, such as causality, mapping, and transfer. Clarifying these correlative relations is the key to the design of production line correlation. In this paper, a descriptive system is built for the production line configuration model, the motion model, the control model, and the optimization model, and the design content of production lines is clarified. A design framework of production line correlation based on the digital twin technology is proposed, and an optimization system of design schemes is built in the form of hierarchical iteration. Polychromatic sets are used to identify the relationship between different dimensions. The high-fidelity simulation ability of the digital twin technology is taken advantage of to verify the proposed four-in-one variant design method in the mobile phone welding assembly line.

Multi-domain Mapping design Method of Automatic Disassembly Equipment for Small Electromechanical Products

The design of automatic disassembly equipment for small end-of-life (EOL) electromechanical products is difficult and time-consuming. To deal with these problems, a novel automatic disassembly equipment design method for small EOL electromechanical products based on axiomatic design and modular design is presented. To realize the mapping from disassembly knowledge to the functional requirements of automatic disassembly equipment, a transfer mapping model from the structure to disassembly methods of small EOL electromechanical products is constructed based on polychromatic sets, which are regarded as the key information of the customer domain. Furthermore, a multi-domain mapping model of the automatic disassembly equipment is constructed through axiomatic design, and the mapping from the customer domain to the functional domain and then to the structure domain in the design process of automatic disassembly equipment is gradually realized. Based on the information in the structure domain, the related modules of the automatic disassembly equipment are divided and designed. Finally, taking a power strip and a set-top box as the experimental objects, the proposed method is applied to the design of automatic disassembly equipment. The results prove that the proposed method improves the design efficiency of automatic disassembly equipment and has strong universality.

Research on Judgment and Solving Strategy of Flow Problems in Complex Engineering Systems

Frequent processes of mutual transfer and transformation generally take place between the material flow, the energy flow, and the information flow in complex engineering systems, and complex coupling relationships exist between the different flows. Abnormal coupling of flows will cause flow problems, which can easily lead to the failure of the system functions. To address these problems, in this study, the starting point has been taken as the change in the attributes and types of the study flow, the attributes of the flows have been categorized, and a flow transfer and transformation model, oriented to the flow problem analysis has been proposed. Secondly, based on the analysis of the effect of the attribute changes of flows in complex engineering systems on the generation of flow problems, an innovatively introduced information processing mathematical tool, the polychromatic sets theory, has been used to explore and determine the flow problems existing in complex engineering systems. Further, depending on the different manifestations of flow problems, three solution strategies have been proposed. Finally, the process model of the flow problem judgment and a solution strategy for complex engineering systems has been constructed. The feasibility of the process model has been verified by considering the engineering case of the tubular feeding machine (TFM) system of a large-scale integrated marine resource survey ship.

A Dynamic and Scalable User-Centric Route Planning Algorithm Based on Polychromatic Sets Theory

Existing navigation services provide route options based on a single metric without considering user’s preference. This results in the planned route not meeting the actual needs of users. In this paper, a personalized route planning algorithm is proposed, which can provide users with a route that meets their requirements. Based on the multiple properties of the road, the Polychromatic Sets (PS) theory is introduced into route planning. Firstly, a road properties description scheme based on the PS theory was proposed. By using this scheme, users’ travel preferences can be quantified, and then personalized property combination schemes can be constructed according to these properties. Secondly, the idea of setting priority for road segments was utilized. Based on a user’s travel preference, all the property combination schemes can be prioritized at relevant levels. Finally, based on the priority level, an efficient path planning scheme was proposed, in which priority is given to the highest road segments in the target direction. In addition, the system can constantly obtain real-time road information through mobile terminals, update road properties, and provide other users with more accurate road information and navigation services, so as to avoid crowded road segments without excessively increasing time consumption. Experiment results show that our algorithm can realize personalized route planning services without significantly increasing the travel time and distance. In addition, source code of the algorithm has been uploaded on GitHub for this algorithm to be used by other researchers.

Reverse design for remanufacture based on failure feedback and polychromatic sets

Design for remanufacture (DfRem) plays an important role in improving remanufacture efficiency of end-of-life (EOL) products. Some studies revealed that the barriers of DfRem are mostly hidden in the failure modes of EOL product. However, one of the DfRem challenges is how to integrate failure feedback into the product’s design process. To address this problem, this study offers a novel Reverse Design for Remanufacture (RDfRem) method to offer redesign strategy for improving the remanufacturability of product based on failure feedback and polychromatic sets. An integrated model, namely, Reverse DfRem Polychromatic Model (RDPM), was developed to describe the relationship among the product’s components, failure modes, scrap modes, economic and obsolescence criteria, and EOL product recovery options based on the theory of polychromatic sets. Thus, the DfRem of product could be formally described mathematically and manipulated by using the computer system. Furthermore, a redesign proposal polychromatic reasoning method was designed to identify the proposed architecture of product. Then redesign proposals were provided to improve the remanufacturability of product. Finally, a simple example was considered to illustrate the entire framework of the proposed method and the case study of an engine validated the feasibility of the method proposed in this study.

Fuzzy polychromatic sets constraint model for route planning problem

Unmanned aerial vehicle route planning is a complex multiconstrained multiobjective optimization problem. Due to the complexity of various constraints and the mutual coupling between them, the expression of constraint conditions is not universal and normative. The development, maintenance, and upgrading of an existing route planning system are very difficult. In this article, by establishing the polychromatic sets of aircraft, aircraft equipment, and flight actions, creating the fuzzy relational matrix between equipment and actions and between actions and actions, this article realizes the standardized and generalized expression of the constraint condition of the route planning problem. Then the analysis and inspection of the constraint conditions are realized by the polychromatic sets operation rules.

A study on Multi-objective Flexible Job-shop Dynamic Scheduling Based on Control Window

It is of great practical significance to study the dynamic scheduling of production in flexible job-shop. In the flexible job-shop scheduling, process, cost, machine tool and processing environment constitute the constraint set of scheduling. In this paper, starting from the multi constraints of scheduling system, the multi-objective linear synthesis of cost, time, quality and resource utilization is carried out. The scheduling intelligent algorithm is improved by using the polychromatic sets contour matrix to improve the operational efficiency. On the basis of the multi-objective flexible job-shop scheduling model under this multi constraints condition, from the actual situation of production scheduling, this paper constructs a scheduling control window according to the dynamic influence domain formed by the dynamic factors in the scheduling process. Dynamic scheduling control is carried out through control window to realize flexible scheduling and intelligent production. The effectiveness and feasibility of the model are verified by dynamic scheduling analysis of a simulation example.

Generalized growth decision based on cascaded failure information: Maximizing the value of retired mechanical products

Remanufacturing can bring substantial environmental benefits by reducing process consumption and resource waste. It has been proved to play an essential role in solving environmental pollution and waste of resources. In the machinery industry with excessive resource consumption, a large number of retired products will be produced during industrial transformation and upgrading. Therefore, remanufacturing and reuse are vital to clean production. Current remanufacturing studies mainly aim at structural recovery and performance improvement, which fail to systematically study the growth laws and generalized reuse features of retired mechanical products. The growth law of retired products is analyzed based on structural and failure features. Therefore, this study will focus on how to establish an appropriate generalized growth decision scheme based on product structure and failure features. Firstly, based on the theory of polychromatic sets, this paper analyzes the failure features of various parts of retired mechanical products and establishes a cascaded failure network according to the product hierarchy. Secondly, through the combination of three-way decision and the technologies for order preference by similarity to an ideal solution (TOPSIS), the generalized growth mode of each component is determined step by step from the bottom, and the generalized growth decision is made from the top. Finally, through the research on the generalized remanufacturing of the first stage gearbox, the generalized growth level of the gearbox is the top-level component level. It reduces the waste of resources and energy consumption caused by the traditional unified part level material recycling, and conforms to the actual production, and verifies the feasibility of the generalized growth features and remanufacturing decision-making scheme, which has excellent guiding significance.

Locating method and motion stroke design of flexible assembly tooling for multiple aircraft components

To get an accurate dimensional size/shape/spatial and assembly accuracy, flexible assembly tooling is developed and applied in aviation production, instead of traditional dedicated rigid tooling. Its configuration can be adjusted to fit different assembly environments and support/locate different components together in correct relative positions. For multiple aircraft components, the optimal design on flexible assembly tooling system, i.e., flexible locating method and motion stroke of different locating units, was studied in this paper. Firstly, to assemble the multiple components with a flexible method, the optional geometric features were defined and divided into several groups, with cluster analysis. Secondly, with two-stage progressive reasoning and the polychromatic set theory, the precise logical mapping relationship between product assembly/coordination requirements and detailed tooling locating methods was proposed. Thirdly, considering the constraints of assembly operation space, assembly constraints (such as assembly loads and locating freedom), product posture, and other specific assembly factors, a design procedure with quantitative analysis and containing eleven steps was proposed and modeled, and then solved with intelligent algorithm. Lastly, flexible design for assembling four different wing flap components was optimized to verify the methodology’s feasibility. The flexible assembly system has a compact/simplified structure, and a sufficient assembly operation space. The layout scheme of the comprised units distributes by three rows, and parallel to each other. And the locating function of end locating effectors is highly integrated with a good flexibility degree. Combined with the practical design and assembly process, the motion stroke fits well with flexible assembly requirements, demonstrating a good locating/assembly performance.

Digital twin-driven 3D visualization monitoring and traceability system for general parts in continuous casting machine

There are lots of general parts with frequent maintenance and high interchangeability for continuous casting machine during its operation and maintenance. To acquire the service information of each general part under the environment of high temperature and serious oil pollution for predicting remaining life and preventative maintenance, a digital twin-driven monitoring and traceability system for general parts in continuous casting machine is proposed. First, the systematic architecture of proposed approach is given in detail, where a typical five-layer model for digital twin-driven monitoring and traceability is established. Second, the Web-based 3D visualization monitoring for continuous casting machine is achieved by using lightweight 3D twin model. After that, an assembly model based on polychromatic sets is built for expressing and describing the assembly relationships and assembly process of general parts. Meanwhile, an encoding rule for part and position is put forward by considering assembly position information. On the basis of that, the general parts with total process information are traced in the service life cycle. Finally, digital twin-based 3D visualization monitoring and traceability prototype system is developed and implemented, where the experiment cases verify the effectiveness and feasibility of the proposed approach.

Structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model

PurposeThree-dimensional computer-aided design (CAD) assembly model has become important resource for design reuse in enterprises, which implicates plenty of design intent, assembly intent, design experience knowledge and functional structures. To acquire quickly CAD assembly models associated with specific functions by using product function requirement information in the product conceptual design phase for model reuse, this paper aims to find an approach for structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model before functional semantic-based assembly retrieval.Design/methodology/approachAn approach for structure-function correlations analysis and functional semantic annotation of CAD assembly model is proposed. First, the product knowledge model is constructed based on ontology including design knowledge and function knowledge. Then, CAD assembly model is represented by part attributed adjacency graph and partitioned into multiple functional regions. Assembly region and flow-activity region are defined for structure-function correlations analysis of CAD assembly model. Meanwhile, the extraction process of assembly region and flow-activity region is given in detail. Furthermore, structure-function correlations analysis and functional semantic annotation are achieved by considering comprehensively assembly structure and assembled part shape structure in CAD assembly model. After that, a structure-function relation model is established based on polychromatic sets for expressing explicitly and formally relationships between functional structures, assembled parts and functional semantics.FindingsThe correlation between structure and function is analyzed effectively, and functional semantics corresponding to structures in CAD assembly model are labeled. Additionally, the relationships between functional structures, assembled parts and functional semantics can be described explicitly and formally.Practical implicationsThe approach can be used to help designers accomplish functional semantic annotation of CAD assembly models in model repository, which provides support for functional semantic-based CAD assembly retrieval in the product conceptual design phase. These assembly models can be reused for product structure design and assembly process design.Originality/valueThe paper proposes a novel approach for structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model. Functional structures in assembly model are extracted and analyzed from the point of view of assembly structure and function part structure. Furthermore, the correlation relation between structures, assembled parts and functional semantics is expressed explicitly and formally based on polychromatic sets.

Optimized Link Distribution Schemes for Ultrareliable and Low-Latent Communications in Multilayer Airborne Networks

Ultrareliable and low-latency communications (uRLLC) is one of the most significant requirements for future wireless networks. The conventional terrestrial base stations cannot always provide the required uRLLC for emerging applications and scenarios, e.g., Tactile Internet services or when a large number of users get connected during an event. Therefore, multilayer airborne networks with low/medium/high altitude platforms can be deployed as an effective solution to offer capacity and coverage along with required latency and reliability for wireless networks. In this article, we propose three layers of the airborne network to support the uRLLC requirement in wireless networks. Optimized link selection schemes have been provided based on polychromatic sets (PSets) theory to focus on the uRLLC. With the optimized link selection algorithm, multiple properties of the airborne platforms are exploited, and the links are selected based on the multiconstrained requirements to support the desired performance of the airborne network. Moreover, two links distribution schemes have been proposed as distributed greedy scheme and centralized greedy scheme to demonstrate the deployment of the proposed airborne network. Numerical results show that both PSets-based links distribution schemes outperform the general distribution schemes on average latency and overall reliability also known as the unassociated ratio, which strongly supports the uRLLC in considered airborne networks.

Product Information Modeling Based on Polychromatic Sets and Scheme Optimum Selection for Conceptual Design

In this paper a conceptual design product information model is established. The polychromatic sets theory was applied to this new model which was aimed at the deficiency of approach for solving product conceptual design presently. This method helps to realize the deduction from requirements to different product scheme combinations by the boolean matrixes which obtains unified colors and individual colors, the constraint relationship in the product model. To solve the conceptual design scheme evaluation problem, a decision-making method was put forward based on fuzzy analytic hierarchy process (AHP) and genetic algorithm (GA) . This approach was designed to convert fuzzy information into numerical value by combining the principles of fuzzy mathematic and information axiom, and use AHP to determine the evaluation index weights . An example of vibration isolation system conceptual design was illustrated the feasibility of this method.

A polychromatic sets theory based algorithm for the input/output scheduling problem in AS/RSs

This paper proposes a hybrid polychromatic sets theory based genetic algorithm (GA) for the input/output scheduling problem of automated storage and retrieval systems (AS/RSs). In order to overcome the drawbacks of precocious phenomena and lack of stability of the GA, a novel hybrid model through integration of genetic algorithm (GA) and polychromatic sets theory (PS) is proposed. During the solution process, polychromatic sets contour matric is used to assign input/output goods location reasonably to improve the quality of initial population. During the iterative process, simulate anneal algorithm (SA) is invoked to jump out of the local optimum to obtain a satisfactory solution. The experiment results showed that the hybrid PS-SA-GA genetic algorithm has obvious advantages in solving the input/output scheduling problems: the introduction of contour matrix constraint module can effectively improve the quality of initial population; the simulated annealing algorithm is invoked to reduce the possibility of premature convergence, and the global optimal solution can be obtained efficiently.

Structural relationship model for design defect and influencing factors in the concurrent design process

Concurrent design is a systematic approach that aims to help developers consider all elements related to the product life cycle, including quality, cost, schedule and user requirement. This approach is challenging because designers conduct these elements manually in the design process. In addition, studies on the formation mechanism of design defects are limited. To minimise the difficulties of product designers and prevent design defects, a structural relationship model is presented for the concurrent design process. The structural relationship model, which incorporates design defects, design process and influencing factors, is marked through polychromatic sets. The interval analytic hierarchy process is used to determine the weight of each influencing factor. Furthermore, a brief model instruction for concurrent design is proposed to guarantee the model application’s validity. The proposed method enables designers to concentrate on functionality and performance design, and the findings are expected to be theoretically and practically useful for preventing and controlling defects in concurrent design.

System Reliability Assessment Based on Failure Propagation Processes

One or several component failures may lead to more related component malfunction and ultimately cause system reliability reduction. Based on this, we focus on the assessment system reliability of complex electromechanical systems (CEMSs) in a fault-propagation view. First, failure propagation model taking into consideration failure data based on network theory and improved polychromatic sets is proposed for system reliability evaluation. From the node point of view, system effectiveness index is constructed to investigate the variation of efficiency of the holistic network. Subsequently, from the system’s perspective, system reliability measurement is provided and estimated in combination with system effectiveness index and failure propagation models. Finally, the application of proposed method to a bogie system of high-speed train assesses system reliability, and meanwhile, the effectiveness of the proposed method is able to be illustrated.

A scalable product configuration model and algorithm

The application of product configuration model is an effective way to improve product design and manufacturing efficiency. The traditional product configuration model has a single configuration result, and the configuration model is difficult to be expanded. In order to solve the existing problem, a scalable product configuration model is established based on polychromatic sets theory and corresponding algorithm is proposed. Firstly, product modules are clustered according to function types to establish function block, which is the solving unit of product configuration model. At the same time, multilayer polychromatic set contour-comprising matrices are respectively established from the point of view of needs, product, performance and module. According to actual demand of product configuration, the unified color reasoning algorithm is proposed. And scalable product configuration model and algorithm are proposed based on relative works. Then, the scalability of proposed model is studied from the point of view of needs change and modules change. Finally, the configuration of a special vehicle is introduced to verify the presented model and algorithm, and the results confirmed the effectiveness and rationality of the method.

Research on the Interoperability of Systems Based on the Polychromatic Sets Theory

In view of the complexity of information system interoperability, a new method based on polychromatic sets theory is proposed, and the research steps are given. Firstly, got a polychromatic graph model for system’s interoperability relationship by analyzing the relations among the subsystems and regard it as the edges, the model’s nodes is subsystems. Secondly, the resources of each interoperability subsystem are analyzed, and the color of the nodes and edges in the polychromatic graph model are determined according to the results of the analysis. Thirdly, the actions of the interoperability subsystems are analyzed. Since the action is a movement of the state, the initial state matrix and the final state matrix of the action based on the theory of polychromatic sets are given to describe the action of the interoperability subsystem. Finally, a formal description method of interoperability system based on the theory of polychromatic sets is presented. On the end, the interoperability of hospital information system as an example to verify the effectiveness of this formal method.

Formalization of Hospital Workflow Process Based on Polychromatic Sets Theory

In order to establish the workflow model, formalized expression of workflow process was studied. The basic conception of polychromatic set is given, to describe the relationship between activities and activities, this paper extends the Boolean matrices in polychromatic sets, on the basis of 0,1 to increase the -1 to identify the relationship between the follow-up relationship, with "+" that the relationship between the activities of the precursor. In addition, in order to construct a complete workflow process, the polychromatic graph is extended. In this paper, the classification of nodes in polychromatic graphs and the addition, deletion and modification of polychromatic graphs are proposed, add a pair of to the edge of the polychromatic graph to indicate the time and resources required to complete the activity. Finally, using the theory presented in this paper to describe the workflow process of hospital radiology.