Develop an autonomous product-based reconfigurable manufacturing system

With the ever-emerging market including mass customization and product variety, reconfigurable manufacturing systems (RMS) have been presented as the solution. A manufacturing system that combines the benefits of the two classic manufacturing systems to increase responsiveness and reduce production time and costs. To cope with the lack of physical systems, an RMS system have been built at UiT Narvik. Today, both reconfiguration and deciding layout must be executed manually by a human. A task that is both incredibly time consuming and far from optimal. A method of automating the layout generation and thus the manufacturing system is presented in this thesis. To the author’s knowledge such experiment has not been performed previously. Layouts is generated with a NSGA-II algorithm in Python by minimizing objectives from a developed mathematical model. The results have been tested with a MiR-100 mobile robot placing five modules in two different layouts. The results have been compared with a digital visualization for validation. In addition to the visualization, videos of the physical system's automated layout generation are presented. The results concludes that the method both generates feasible layouts as well as enhancing the automation of the system

"Going back to our roots": second generation biocomputing

Researchers in the field of biocomputing have, for many years, successfully "harvested and exploited" the natural world for inspiration in developing systems that are robust, adaptable and capable of generating novel and even "creative" solutions to human-defined problems. However, in this position paper we argue that the time has now come for a reassessment of how we exploit biology to generate new computational systems. Previous solutions (the "first generation" of biocomputing techniques), whilst reasonably effective, are crude analogues of actual biological systems. We believe that a new, inherently inter-disciplinary approach is needed for the development of the emerging "second generation" of bio-inspired methods. This new modus operandi will require much closer interaction between the engineering and life sciences communities, as well as a bidirectional flow of concepts, applications and expertise. We support our argument by examining, in this new light, three existing areas of biocomputing (genetic programming, artificial immune systems and evolvable hardware), as well as an emerging area (natural genetic engineering) which may provide useful pointers as to the way forward.Comment: Submitted to the International Journal of Unconventional Computin

A Framework for Automatically Realizing Assembly Sequence Changes in a Virtual Manufacturing Environment

© 2016 The Authors. Global market pressures and the rapid evolution of technologies and materials force manufacturers to constantly design, develop and produce new and varied products to maintain a competitive edge. Although virtual design and engineering tools have been key to supporting this fast rate of change, there remains a lack of seamless integration between and within tools across the domains of product, process, and resource design-especially to accommodate change. This research examines how changes to designs within these three domains can be captured and evaluated within a component based engineering tool (vueOne, developed by the Automation Systems Group at the University of Warwick). This paper describes how and where data within these tools can be mapped to quickly evaluate change (where typically a tedious process of data entry is required) decreasing lead times and cost and increasing productivity. The approach is tested on a sub-assembly of a hydrogen fuel cell, where an assembly system is modelled and changes are made to the sequence which is translated through to control logic. Although full implementation has not yet been realized, the concept has the potential to radically change the way changes are made and the approach can be extended to supporting other change types provided the appropriate rules and mapping

EFFICIENCY OF FLEXIBLE FIXTURES: DESIGN AND CONTROL

The manufacturing industries have been using flexible production technologies to meet the demand for customisation. As a part of production, fixtures have remained limited to dedicated technologies, even though numerous flexible fixtures have been studied and proposed by both academia and industry. The integration of flexible fixtures has shown that such efforts did not yield the anticipated performance and resulted in inefficiencies of cost and time. The fundamental formulation of this thesis addresses this issue and aims to increase the efficiency of flexible fixtures.To realise this aim, the research in this thesis poses three research questions. The first research question investigates the efficiency description of flexible fixtures in terms of the criteria. Relative to this, the second research question investigates the use of efficiency metrics to integrate efficiency criteria into a design procedure. Once the efficiency and design aspects have been established, the third research question investigates the active control of flexible fixtures to increase their efficiency. The results of this thesis derive from the outcome of seven studies investigating the automotive and aerospace industries. The results that answer the first research question use five criteria to establish the efficiency of flexible fixtures. These are: fundamental, flexibility, cost, time and quality. By incorporating design characteristics in respect of production system paradigms, each criterion is elaborated upon using relevant sub-criteria and metrics. Moreover, a comparative design procedure is presented for the second research question and comprising four stages (including mechanical, control and software aspects). Initially, the design procedure proposes conceptual design and verification stages to determine the most promising flexible fixture for a target production system. By executing detailed design and verification, the design procedure enables a fixture designer to finalise the flexible fixture and determine its efficiency. Furthermore, a novel parallel kinematics machine is presented to demonstrate the applicability of the design procedure’s analytical steps and illustrate how appropriate kinematic structures can facilitate the efficiency-orientated design of flexible fixtures.Based on the correlation established by the controller software’s design procedure, the active control of flexible fixtures directly affects the quality criterion of flexible fixture efficiency. This provides the answer to the third research question, on general control strategies for active control of flexible fixtures. The introduction of a system model and manipulator dynamics proposes force and position control strategies. It is shown that any flexible fixture using a kinematic class can be controlled, to regulate the force and position of a workpiece and ensure that process nominals are preserved. Moreover, using both direct and indirect force control strategies, a flexible fixture’s role in active control can be expanded into a system of actively controlled fixtures that are useful in various processes. Finally, a position controller is presented which has the capacity to regulate both periodic and non-periodic signals. This controller uses an additional feedforward scheme (based on the Hilbert transform) in parallel with a feedback mechanism. Thus, the position controller enables flexible fixtures to regulate the position of a workpiece in respect of any kind of disturbance

Co-evolution in Manufacturing Systems Inspired by Biological Analogy

The artificial world experiences continuous changes that result in the evolution of design features of products and the capabilities of the corresponding manufacturing systems similar to the changes of species in the natural world. The idea of simulating the artificial world, based on the analogy between the symbiotic behaviour of products and manufacturing systems and the biological co-evolution of different species in nature, is expressed by a model and novel hypotheses regarding manufacturing co-evolution mechanism, preserving that co-evolution and using it for future planning and prediction. Biological analogy is also employed to drive the mathematical formulation of the model and its algorithms. Cladistics, a biological classification tool, is adapted and used to realize evolution trends of products and systems and their symbiosis was illustrated using another biological tool, tree reconciliation. A new mathematical method was developed to realize the co-development relationships between product features and manufacturing capabilities. It has been used for synthesizing / predicting new species of systems and products. The developed model was validated using machining and assembly case studies. Results have proven the proposed hypotheses, demonstrated the presence of manufacturing symbiosis and made predictions and synthesized new systems and products. The model has been also adapted for use in different applications such as; system layout design, identifying sustainable design features and products family redesign to promote modularity. The co-evolution model is significant as it closes the loop connecting products and systems to learn from their shared past development and predict their intertwined future, unlike available unidirectional design strategies. The economic life of manufacturing systems can be extended by better utilizing their available capabilities, since the co-evolution model directs products - systems development towards reaching a perfect co-evolution state. This research presents original ideas expressed by innovative co-evolution hypotheses in manufacturing, new mathematical model and algorithms, and demonstrates its advantages and benefits in a wide range of applications

A framework for automatically realizing assembly sequence changes in a virtual manufacturing environment

Global market pressures and the rapid evolution of technologies and materials force manufacturers to constantly design, develop and produce new and varied products to maintain a competitive edge. Although virtual design and engineering tools have been key to supporting this fast rate of change, there remains a lack of seamless integration between and within tools across the domains of product, process, and resource design - especially to accommodate change. This research examines how changes to designs within these three domains can be captured and evaluated within a component based engineering tool (vueOne, developed by the Automation Systems Group at the University of Warwick). This paper describes how and where data within these tools can be mapped to quickly evaluate change (where typically a tedious process of data entry is required) decreasing lead times and cost and increasing productivity. The approach is tested on a sub-assembly of a hydrogen fuel cell, where an assembly system is modelled and changes are made to the sequence which is translated through to control logic. Although full implementation has not yet been realized, the concept has the potential to radically change the way changes are made and the approach can be extended to supporting other change types provided the appropriate rules and mapping

Design And Analysis Of Mechanical Mating Interfaces For Reconfigurable Machine Tools

Reconfigurable Machine Tools (RMTs) which are designed under modularity concept are a new approach in machine tools technology which is characterized by customized flexibility to serve current production requirements. It allows changes in machine physical configuration whenever required. This concept of machine tools is still under development stage. Even though there are numbers of design methodologies proposed, there is no method specifically mentioned on how each module would be assembled together. Using a structured design approach, the newly design of mechanical mating interface method is proposed. Two non-vertex cones with pin-slot arrangement were found to be the best concept. Using Finite Element Method (FEM), the detail design on the optimum design variables was determined. The stiffer assembly was assured when the ratio of depth of penetration to the total mating interface thickness used is 0.6. The 1/10 tapered angle was the best value for the cones and 0.15 mm of the face clearance between mating interfaces ensured 5μm of interference fit. Using simulation modelling, the performance of the newly designed mating interface was investigated and compared with conventional interface method. The newly designed mating interfaces were confirmed to perform better compared to conventional method. Finally, the tolerance analysis was conducted and appropriate tolerance values were allocated. The intended interference fit of the assembled modules was achieved