PRODUCT LIFE CYCLE IN DIGITAL FACTORY SVOČ FST 2011

Transcription

1 PRODUCT LIFE CYCLE IN DIGITAL FACTORY SVOČ FST 2011 Ondřej Kurkin, West Bohemia University, Univerzitni 8, Pilsen Czech Republic ABSTRACT This paper is focused to the usage of digital factory concept in the design of the product and its production system. It is similar to PLM and includes product design, its engineering and technological design, the proposal of the production system for the product and its validation using ergonomic analysis, and the final section is the simulation of production. From a global perspective, one can conclude that the production system is considered a product. KEYWORDS Digital Factory, PLM, Simulation, Ergonomic INTRODUCTION New Product Development in the Digital Factory can be divided into several stages: Concept of product The design concept of designer engineer Production technology Designing of a workplaces Designing of a production system Ergonomic analysis of workplaces Simulation of the production Implementation of the project DESIGN OF THE CONCEPT Designer creates the products to meet customers needs according to the demand suggested by research. It is an idea of appearance and function rather than the products capability and appearance. This proposal is designed for engineers in their work. In our case, we chose RC model of car as our product. Fig. 1. Design of the concept ENGINEERING DESIGN Engineering designer makes documentation for the technology. His aim is to design individual parts of the assembly that the total product meets all the required functions. There are a design tools (CAD systems) which are part of a package of digital factory for this purpose. There are only two companies which are providing full package of Digital Factory. Dassault systems (with CAD system Catia) SIEMENS (with CAD system NX)

2 These engineering tools allows designer to: Design of individual components of the product Static and dynamic analysis Virtual simulation and report completion of its functionality Creation of technical documentation for technology In our case, we chose a suspension arm for the stress analysis and analysis of the technology. Fig. 2. Examples of work in design tool NX TECHNOLOGICAL SOLUTIONS After that the designer creates drawings, process engineer begins with designing of the manufacturing process for individual components and their subsequent assembly into a complete assembly. The manufacturing process means: Choosing of working machines and tools for the production of individual components Determination of working conditions Generation of CNC programs (if there are used CNC machines in the production) We can use of technological modules which are parts of the CAD systems (CATIA and NX). These modules allow engineers to virtually simulate a manufacturing process. Technologist can choose: Method of machining Cutting machining conditions The control system of CNC machine Analyze a precision after machining On Fig.3 you can see a design of injection head for production suspension. There is example of machining of the main board of the injection head. When control system is defined (in our case SINUMERINK) technologist can simulate a progress of machining. It can simulate only a cutting tool or whole machine. The biggest advantage of this technological module (in case of NX) is that we can simulate that the machine runs directly according to the CNC program. In many other technological tools, the simulation is run only by the CL data, which are not gone through the post-processor. Injection Head Simulating of the cutting tool Simulating of the machine Analysis of a precision after machining Generated NC program Fig. 3. Examples of technological operations in NX

3 DEFINING OF THE PRODUCTION PROCESS When technology is ready for production, according type of a production industrial engineer has to design production process. Industrial engineer has to: Design a production processes Set the tact of the production line Design a individual workplaces Design a manufacturing system Design a supplies Ergonomic analysis of workers We will use package digital factory for this purposes again. In our case, the production system is modeled in product Tecnomatix. Design of the processes is divided to several steps: Rough planning Fine planning Simulation and verification of the fine planning Ergonomic analysis of the workplaces Discrete event simulations of the manufacturing system ROUGH PLANNING There are defined resources, products and processes of individual operations in rough planning. We use the Process Designer for these tasks. Resources Resources encompass everything needed to ensure the process eg workbench, tools and workers themselves. The Fig.4 shows the layout of resources. Fig. 4. layout of resources for production of RC car Products Products are components of the input and output sub-assemblies of components or assemblies. In our case, Products are parts of a RC car. On Fig.5 You can see tree of parts and assemblies of our mode Part of RC car Fig. 5. Product tree Product tree

4 Process The process changes inputs to outputs using resources. We split an operation to sub-operations in rough planning eg: vice a part to mounting device or move the box with the material. The big advantage of the Process Designer, are time tables with the MTM codes. You can simply define an operation eg: fixing a part to mounting device and Process Designer automatically calculates according a MTM codes operation times. FINE PLANNING Process Simulate serves to verify of assigned times from Process Designer. Process Simulate is a simulation tool for real simulations such as human motion in the assembly operations. Operations are defined to the sub-tasks such as finger grips for gripping parts, etc. After running the simulation, we have a new (simulated) times of operations. This new times will be compared with times from Process Designer. We can decide which time we will use in project. The Fig.6 shows the difference in the times from Process Designer and Process Simulate. Process Simulate is also used for verifying collisions in automated robotic manufacturing. Simulations of robot motions can help with organizing of workplaces. On Fig.6 the lower picture shows more detailed planning of operations. There you can see a difference in time of first sub-operation. Difference in time is 0.3 seconds compared to rough planning Fig. 6. Rough and Fine Planning ERGONOMIC ANALYSIS We are testing an individual workplace after defining the operations, resources and products. There is a ergonomic tool JACK for this tasks. This tool contains a realistic model of a man with ties to the bones, muscles, joints, etc. You can set a male of human, weight, height. All these proportions affect a human at work. According to the results of each analysis, it is necessary to modify the workplace for the worker. After this we can again simulate a production process in Process Simulate. This cycle is repeated until we achieve the best results. Fig. 7. Ergonomic tool JACK

5 DISCRETE EVENT SIMULATION The last part of the package of Digital Factory is a simulation tool Plant Simulation for discrete simulations of manufacturing processes. After ergonomic analysis in JACK, we can export a data from Process Designer to Plant Simulation. We can simulate different situations which can occur in production process. We can define cost time, number of scrap, machine failures, etc. and in the report we can see eg costs per period, investment per period number scrap etc. Fig. 8. Discrete event simulation, in Plant simulation 9 CONCLUSION In today's globalized era, Ahead of the competition means a distinct advantage in the market in today's globalized era. Every investment should be very well considered. The biggest advantage of the Digital Factory is that everything happens in the virtual world. It is possible to test numerous scenarios and problems that might arise in real business. When a problem occurs in the virtual model is not difficult to remove it, but in real company are these solutions of any problems very expensive. Another big advantage is the data consistency. We have a data format which can work with all of the tools of the package. The cost of the digital factory is only the cost of time spent preparing the virtual model and the cost of software. Each enterprise must consider whether it is advantageous to him the whole package or just some debris from the instruments. In our example is shown in virtually all life-cycle of the product to distribution of the product (not included here to return the product). Each tool can be used separately. ACKNOWLEDGMENT This paper was created with the subsidy of the project 402/08/H051 under the Grant Academy of the Czech Republic. The name of this project is Optimization of multidisciplinary design and modelling of virtual firm s production systems. REFERENCES [1] TUPA, J.; KAŠPAR, P.; BASL, J. Process Performance Management Application for Technological Process Control. In Proceedings of the 17th International Conference on Flexible Automation and Intelligent Manufacturing. Beijing : Hongde Tongda, s ISBN [2] VOTAVA, V. ULRYCH, Z. EDL, M. - KORECKÝ, M. TRKOVSKÝ, V. Analysis and Optimization of Complex Small - Lot Production in New Manufacturing Facilities Based on Discrete Simulation. In: 20th European Modeling & Simulation Symposium (EMSS 2008), Campora San Giovanni, Amantea (CS), Italy, September 17-19, ISBN [3] Saaty L. T. & Vargas G. L. (2006). Decision making with the analytic network process: economic, political, social and technological applications with benefits, opportunities costs and risks, Springer Science + Business Media, LLC, ISBN , New York, USA [4] Internal materials and manuals from SIEMNS PLM Software [5] BANKS, J., CARSON, S J., NELSON L B., NICOL, M D. (2005) Discrete-Event System Simulation, Pearson Prentice Hall, New Jersey ISBN [6] Votava, Václav. Simulace ve strojírenství. 1. vyd. Plzeň : Západočeská univerzita, ISBN [7] ŠIMON, M. and ČERNÝ, Z.(2009): Strategic planning of joint logistics at the level of horizontal cooperation, In Annals of DAAAM for 2009 & Proceedings of the 20th international DAAAM symposium, 2009, str , ISBN [8] Internal materials and manuals from SIEMNS PLM Software