Recent Research on Computer-Aided Fixture Planning

Flexible fixturing is an essential ingredient of flexible manufacturing systems (FMS) and computer-integrated manufacturing systems (CIMS). Computer-aided fixture design (CAFD) has become a research focus in implementing FMS and CIMS. This paper, presents an overview of interactive computer software developed with CAD interface for designing fixtures for machining centers (HMC/VMC). An exhaustive set of structured queries incorporated in the preprocessor prompts the designer to extract qualitative and quantitative part features. The database and decision support system (i.e., the rule base and the knowledge base) built into the design module assist the designer to select and position locators, calculate clamping forces, decide number and types of clamps, their locations and orientations, etc. Finally, in the post processor the bill of material, part and assembly drawings are obtained. A case study for the design of fixture for a Roller-head is presented and results are discussed. The implementation of the system has proved to be a quick and effective tool that reduces the design lead time from a few days to a few hours and requires fractional efforts and expertise on the part of the designer.

Framework for The Development of a New Reconfigurable Guillotine Shear and Bending Press Machine

A novel planning system which can automatically accomplish machining plans with the appropriate fixture setup and inspection strategies have been presented. In this work, the primary steps that are required to achieve an automated process scheme, modular fixture design, and inspection planning have been described. The object-oriented approach has been employed to attain automation and integration of the design process, including fixtures and inspection modules. This kind of system is unique as it provides an integrated platform for three important manufacturing activities, namely process planning, fixture design, and inspection. The STEP has been employed as an input to the proposed framework. The computer-aided process planning module consists of geometric and dimensional data, machining feature recognition information and process planning files. The modular fixture layout design has been developed using the set of defined rules, search strategies and the graphical database of various fixturing components. The computer-aided inspection planning module automatically generates an inspection plan and Dimensional Measuring Interface Standard code for coordinate measuring machines. It is noticeable from the reported case study and its outcomes that the developed integrated environment can effectively be employed in different manufacturing industries for automated process planning, fixture design, and inspection.

PurposeThe generic design environment for a flexible printed‐circuit board assemblies (PCBA) remanufacturing cell contains four interrelated complex design domains. Mechanical design domains are really complex and the use of well‐proven mechanical product design methodologies does not help the designer. Hence, this paper aims to develop a generic systematic design methodology for a flexible PCBA remanufacturing cell.Design/methodology/approachThe study investigates the use of conventional mechanical product design techniques for the design of a flexible PCBA rework (remanufacturing) cell. It indicates problems and the weaknesses when conventional product design techniques are used for the development of flexible manufacturing systems (FMS). It then provides a new systematic mechanical design methodology for designing a flexible PCBA rework (remanufacturing) cell. The design methodology is intended to be generic in order to apply successfully to any FMS design.FindingsConventional product design methodology cannot be used directly for the design of a flexible PCBA remanufacturing cell. Hence, two design methodologies were developed: the generic FMS mechanical design methodology and a specific FMS design methodology for a PCBA rework cell. The first one was developed based on the tasks of the conventional product design process integrated with new design tools. The generic design methodology was then extended to obtain the second methodology for a PCBA rework cell design. Both of the methodologies were applied to a flexible PCBA rework cell design problem. Both design methodologies eliminated unusable design solutions at the early design stages of the conceptual design process and made the design process easier.Practical implicationsThe generic and specific design methodologies provide a better design environment, even for less specialized FMS designers.Originality/valueThe design methodologies may help for the commercialization of a flexible PCBA remanufacturing cell that may be used for SM rework and assembly.

Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information (PMI) stored in the neutral standard for the exchange of product model data (STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol (AP) 242 files of computer aided design (CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software “FiXplan”, developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece. The area-ratio (base locator enclosed area (%)/work piece base area (%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations. The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.

Chapter 3 - Computer-aided fixture design

Advances in the technology of flexible manufacturing systems, and the introduction of concurrent engineering of product and process design have propounded the need for computer aided fixture design systems. Computer aided process planning is the interface between design and manufacturing and has a key role in achieving integration between the various modules in an FMS environment. Fixture design is inseparable from process planning, and hence to be of practical use any CAPP system must include fixture design. The past few years have seen great advances in automated fixture design systems and the tools used to achieve them. With the exception of fixture design for a limited range of products with close family similarity, fully automated design of practical fixtures is not yet achievable. The advances described in this book have widened the scope of application of computer aided fixture design and provide enhanced links with other product and process design activities.

Technologies such as Autonomous Guided Vehicles (AGVs) and the Internet of Things (IoT) increasingly disrupt traditional manufacturing and production systems. However, there is a scarcity of empirical studies synthesising and evaluating the impact of disruptive technologies on existing manufacturing systems. This study examines the impact of AGVs applying IoT on Flexible Manufacturing Systems (FMS) through a case study demonstrating the integration of AGVs with IoT in a manufacturing company. As a concept, FMS was conceived decades ago; this study uses socio-technical systems theory to elaborate the concept of FMS into the current context. Key themes uncovered from the literature review include (i) AGVs in warehouse systems, (ii) AGV scheduling and routing, (iii) Human-machine interface, and (iv) integrating and controlling AGVs/IoT. The case study demonstrates how AGVs can create smart, flexible manufacturing systems by taking the following steps: (a) problem identification, (b) performance measurement, (c) designing the proposed solution, (d) evaluate IoT systems, (e) implementation of the new solution, and (f) future improvements. The study concludes with specific recommendations to implement Industry 4.0 in manufacturing companies.

Locating completeness evaluation and revision in fixture plan

In this study, a new and simple alternate routing heuristics, which would be superior to the conventional routing strategies in terms of various system performance measures and easier to apply practically, was presented. Because of the high investment costs of FMSs, it is also definitely worth choosing the best operating policy and system configuration by analyzing the system model, and adapting to changes over time. In future research, the heuristic rule base will be extended to include other supplementary constraints such as dynamic tool allocation and sequence dependent setup times. For practical implementation of the proposed decision support system, additional research in the area of human interfaces could be useful to develop more user friendly system which automatically constructs simulation model of the system from the knowledge base of a production system.

Self-Organising Electronic Institutions and Flexible Manufacturing Systems

Summary form only given as follows. As manufacturers face a more competitive environment, they are forced to satisfy needs for productivity and flexibility simultaneously. To satisfy these needs and remain competitive, many manufacturers are upgrading their manufacturing technology by introducing flexible manufacturing systems (FMS). The evidence, however, suggests that the payoffs from investing in FMS will not be adequate unless manufacturers also ensure their human resources lever the new technology. The programmable capabilities of FMS are limited to handling quickly and efficiently the more routine aspects of variable manufacturing processes. For FMS to achieve economies of scope and fulfil their promise, FMS need to be staffed by individuals who can lever FMS. These are individuals who can work with FMS, and who can go beyond the limitations of FMS by handling quickly and efficiently the less routine aspects of these manufacturing processes. To lever FMS, human resources need to be managed differently than in traditional factories. They need to be organized into self-managing teams; they need to be classified into few job categories; they need to be selected because of their FMS matching characteristics; they need to be trained; and they need to be rewarded for their varied skills and cooperation. Moreover, they need to be empowered by managers who substitute the coaching approach for the command and control approach, and who seek closer union-management relationships.

Flexible manufacturing systems (FMS), transitional or absolute customer to encounter the various requirements and preferences, helping to protect organizations which in the circumstances of competitive environment in eachother exactly known always to created, are constructed as a structure that could really keep producing various products and services with minor modifications. Computers are used to help manufacturing lines. This research provides the literature review of manufacturing-production systems, categorisation of manufacturing techniques, advanced manufacturing technologies, manufacturing process modeling, modeling definitions, and database organizational structures, data regulations and procurement for Flexible Manufacturing Systems-Techniques, and eventually the research conclusion and recommendation. Mostly with significant developments in the manufacturing sector, the database idea has become an essential and fundamental element of every type of production system. Its most fundamental tasks are the preservation and accessibility of services required to regulate industrial operations. This study also utilizes SWOT (Strengths, Weaknesses, Opportunities, and Threats) evaluation to explore the appropriateness of manufacturing techniques, FMS in industrial manufacturing automated processes. The highlighted elements indicate manufacturing systems' considerable potential to address advanced manufacturing modernization challenges.

To simulate and debug or diagnose manufacturing systems is always challenging. This paper presents a hybrid PLC-controlled and PC Visual Basic (VB)-based Human-Machine Interface (HMI) platform based on Petri net (PN) theory for Manufacturing Systems. An augmented PN model was adopted to design and simulate the operational sequence of the Flexible Manufacturing System (FMS) at the National Kaohsiung First University of Science and Technology (NKFUST). With the simulated PN model, the control sequences were quickly translated into PLC programs. A PC-based HMI monitoring system based on the PN model was developed to provide an intuitive offline simulation and online diagnostic tools for the FMS. This hybrid system shows many of advantages by using the economical discrete control unit with PLC, and PC-based HMI using PN model as a base. The discrete event control sequence of an FMS can be easily modeled and evaluated before its build-up. More importantly, it can be diagnosed online when the system is malfunctioning. That is, the presented system provides an adequate means for offline system design, simulation, performance evaluation, and quick online system diagnostic.

Comparison of Limit Surface Approach with other Approaches in Fixture Planning with Friction