Generalized Kinematic Modeling Method for Reconfigurable Machine Tools

In response to the need for cost-effective systems than can be quickly adapted to changes in product design and manufacturing processes, the next generation of machine tools should be reconfigurable and intelligent. Reconfigurability allows for the reduction of machine design lead time, machine set-up and ramp-up time. The principal characteristics of the Reconfigurable and Intelligent Machines are modularity, convertibility, flexibility and cost-effectiveness. This paper applies a concurrent design reference model to Reconfigurable Machine Tool development. A methodology for this purpose is introduced, and the bottlenecks in the process are identified, namely, the procedure to design modules. In response, a technique for the development of modules that are consistent with the product portfolio of the machine tool builder is outlined.KeywordsModularityReconfigurabilityConcurrent DesignMachine Tool

Reconfigurable manufacture system is to list as one of key technologies which will first solve in the future manufacturing, this article will mainly solve research on theory of reconfigurable for NC machine tool. Reconfigurable machine tool has many merits that include modularization, integration, custom-made, convertibility and so on. That is the traditional machine tool cannot compare.This article has carried on the analysis from the deep hole components classification and the formed movement craft two aspects to the deep hole components race. The reconfigurable deep hole machine tool was to carry on the modular design based two aspects for the module partition and reconstructable analyze, solved the key technologies the machine tool modulation design. From the machine tool bed module, the head of machine tool module, the cutting tool auxiliary system and the numerical control system four aspects, to design and research on reconfigurable machine tool, solved the difficult design problem which the part reconfigurable designed. Finally uses the ultrasonic wave examination technology, has realized numerical control machine tool element level restructuring. (5 pages)

In this paper, we present a systematic methodology for designing Reconfigurable Machine Tools (RMTs). The synthesis methodology takes as input a set of functional requirements — a set of process plans and outputs a set of kinematically-viable reconfigurable machine tools that meet the given design specifications. We present a mathematical framework for synthesis of machine tools using a library of building blocks. The framework is rooted in (a) graph theoretic methods of enumeration of alternate structural configurations and (b) screw theory that enables us to manipulate matrix representations of motions to identify appropriate kinematic building blocks. The methodology described in this paper provides a mathematical framework to address dynamic stiffness, and accuracy prediction of the kinematically-viable designs that are generated by the synthesis procedure. This methodology has been implemented in a program, called PREMADE (PRogram for REconfigurable MAchine tool DEsign), and the results are validated against commercial machine tool designs.

The objective of this research was to integrate an Electrical Discharge Machining module onto an existing reconfigurable CNC machine tool, using a modular approach, which potentially would enable conventional milling and EDM to be conducted in a co-ordinated fashion on the same machine tool. Ideally, multi-axis EDM is desired; however, single axis investigations were first done, as a step towards this ideal. The investigations determined which possible integration options should be pursued. This paper considers these single-axis investigations. The integration strategies implemented and evaluated in this research were (a) using the EDM machine's servo-drive output to drive the Reconfigurable Machine Tool's Z axis servo motor, via an external amplifier, (b) using a control signal from the EDM machine to communicate with the PC-based CNC control program (Mach3) to achieve advancement and retraction of the electrode using the RMT's Z axis servo motor, but governed by the EDM process, and (c) using an external controller, effectively replacing the EDM machine's controller and the CNC controller, while providing actuation of the electrode by means of a moving coil linear actuator mounted on the (now fixed) Z axis of the CNC machine. The external controller was implemented in LabVIEW, using a data acquisition device. The third strategy required that a voltage monitoring circuit be implemented to sense conditions at the EDM process spark gap. Single axis EDM was implemented using this method, but a version of the controller for potential 2-dimensional machining was also developed. PC simulation models of the linear actuator, controller, and EDM process were produced.

Reconfigurable Machines form a new class of machines that are designed around a specific part family of products and allow rapid change in their structure. They are designed to allow changes in production requirements by changes in the machine mechanical configuration and structure. Reconfigurable machines might be designed for various types of production operations such as machining, inspection and assembly. This paper introduces characteristics and design principles of reconfigurable machines, and describes their features using an example of our new full-scale industrial prototype of a Reconfigurable Bore Surface Inspection Machine (RBSIM). In addition, the paper also describes briefly other three prototypes of Reconfigurable Machines that were developed during recent years in our center: (1) the Reconfigurable Machine Tool (RMT), (2) the Reconfigurable Inspection Machine (RIM), and (3) the Reconfigurable Assembly Machine (RAM).

From 2010 to 2016, as part of the priority programme SPP1476 “Small Machine Tools for Small Workpieces” funded by the German Research Foundation (DFG) a new modular machine tools concept was scientifically established. The SPP1476 consisted of 13 projects from 18 leading institutes of Production Technology allocated to 13 German universities and research organisations. The objective of the priority programme was to solve the anomaly of an inappropriate machine tool size to workpiece size ratio. This was done by interdisciplinary and multidisciplinary development of new approaches for machine tools, which are used for manufacturing small parts, based on a methodical concept. By the consistent use of enablers which arise from miniaturisation, new allocation of machine elements to functions was possible. The individual project partners developed different modules for modular small machine tools. This includes various tools, feed units, a measurement system, machine frame, interface and other additional modules. Eventually, the generated methods have been validated by the realisation of prototypes and the configuration and assembling to functional machines tools.

Machine tool selection plays important role regarding process of decision making in several companies involved in manufacturing. Machines which are not properly selected, may affect negatively the overall production system performance. The machine tool selection problem within available possibilities proved to be a critical issue among companies in competitive environment from long past. As several alternatives and criteria of selection are available, this problem is converted into MCDM (multiple criteria decision making) problem for machine tool selection. Hence maximum companies adopted several methods for successfully solve this time consuming as well as typical problem. In this paper, mostly used two MCDM methods are introduced viz-modified fuzzy TOPSIS & AHP (Analytical her Process) for presenting an analysis of performance for the problem of machine tool selection. As the global competition in the market is very high, companies are bound for focusing upon high productivity with minimum cost with the use of correct machine tool selection. Appropriate machine tool selection enables saving of labour, quality of product improvement & rate of production increment at the same time overall productivity increment. Machine tool evaluation & selection is a complicated problem for decision making as it involves several criteria with conflicts. In this work, we presented the logical method for evaluating computer numerical controlled (CNC) machine from the point of view of cost & system specifications with the use of method of fuzzy TOPSIS. We get highly promising results when selection problem with CNC machine was solved with respect to the past research.

A reconfigurable manufacturing system is one designed for rapid change in its structure, to quickly adjust its production capacity and functionality within a part family. Aiming at the diversity, cost and complexity of reconfiguration design, a method for evaluating the design scheme of a reconfigurable machine tool based on VIKOR is proposed. The module similarity between a reconfigurable machine tool and a prototype machine tool is defined, and on this basis, three quantitative evaluation indicators are established as follows: the module chain similarity determines the difficulty, effort, time and efficiency of machine tool reconstruction; the module interface complexity determines the feasibility and complexity of the disassembly and assembly of the reconfiguration module; and the reconfiguration cost determines the economic advantages of reconfigurable machines relative to fixed-structure equipment. According to three indicators, a multi-attribute decision-making method based on VIKOR is used to evaluate, calculate and sort the design scheme set of the reconfigurable machine tool, and the optimal feasible solution is obtained. An example of the reconfiguration design of a machine tool is analysed to verify the validity and feasibility of the proposed method compared with the methods of simple average weighting and technique for order preference by similarity to an ideal solution.

The current domestic and international structure of reconfigurable robot and reconfigurable machine tool have been studied by us, their topological characteristics and methods of conversion were summed up, the method of reconfigurable machine to converter topology was found to achieve the purpose of reconstruction of the machine comparing the two different areas of the module types and functions.

In today's market, demand fluctuation is a big challenge for manufacturers. They have to respond quickly and flexibly to satisfy customers' demands to improve competitiveness. Moreover, it renders the production systems complex and dynamical. In this paper, we use capacity adjustment to deal with the fluctuation in demand. We derive an extended mathematical model of a typical job shop manufacturing system by introducing reconfigurable machine tools (RMTs) to analyse the impact of this new class of machine tools on the dynamic behaviour of the system. To improve the ability of capacity adjustment, we include the operations of RMTs into the classical proportional integral derivative (PID) controller. Simulation results of a four-workstation job shop system demonstrate the proposed method can adjust the capacity effectively and show the potential of RMTs in the context of Industry 4.0.

Drilling reconfigurable machine tool selection and process parameters optimization as a function of product demand

Machine tool is the basic equipment of machinery industry, playing very important role in today's manufacturing, and its variety, quality and processing efficiency directly affects economic benefits and the technology level of the mechanical industry production. The modular machine tool is widely used in the industry, and its production efficiency is increased by several times or even several times than the common machine tool, with such processing methods of multi-axis, multi-knife and multi-process. This paper designs the small combined machine with a set of turning, milling, drilling and grinding by PTC's 3D software, namely Pro/Engineer. At last, the technique of the interference analysis and visual simulation has been carried on, verifying the feasibility of the machine design. The machine tool is mainly used to meet the needs of processing the small parts in scientific research, teaching unit or small repair industry, not only improving the machining efficiency, but also saving space and processing costs.

Cooperative optimization of reconfigurable machine tool configurations and production process plan

a new 4-axis machine tool, which is used to relief grind sphere gear hob including spherical hob, elliptic hob and arc surface hob, is developed. The principle of machining of spherical hob is introduced first. Transmitting system, numerical system and some key techniques are then introduced. The machine tool can be reconfigured when machining of arc worms and spatial cams beside of machining spherical hob. Four forms of the machine tool for machining different workpiece are also introduced.

Integrated Lot-sizing and Job Shop Scheduling Benefiting From Reconfigurable Machine Tools