scholarly journals A Holonic-Based Self-Learning Mechanism for Energy-Predictive Planning in Machining Processes

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 739 ◽  
Author(s):  
Seung-Jun Shin ◽  
Young-Min Kim ◽  
Prita Meilanitasari

The present work proposes a holonic-based mechanism for self-learning factories based on a hybrid learning approach. The self-learning factory is a manufacturing system that gains predictive capability by machine self-learning, and thus automatically anticipates the performance results during the process planning phase through learning from past experience. The system mechanism, including a modeling method, architecture, and operational procedure, is structured to agentize machines and manufacturing objects under the paradigm of Holonic Manufacturing Systems. This mechanism allows machines and manufacturing objects to acquire their data and model interconnection and to perform model-driven autonomous and collaborative behaviors. The hybrid learning approach is designed to obtain predictive modeling ability in both data-existent and even data-absent environments via accommodating machine learning (which extracts knowledge from data) and transfer learning (which extracts knowledge from existing knowledge). The present work also implements a prototype system to demonstrate automatic predictive modeling and autonomous process planning for energy reduction in milling processes. The prototype generates energy-predictive models via hybrid learning and seeks the minimum energy-using machine tool through the contract net protocol combined with energy prediction. As a result, the prototype could achieve a reduction of 9.70% with respect to energy consumption as compared with the maximum energy-using machine tool.

Author(s):  
Yaoyao F. Zhao ◽  
Frederick M. Proctor ◽  
John A. Horst ◽  
Xun Xu

Machining process planning and measurement process planning have long received research attention from industry and academia. Machining and measurement process automation is well established for mass production in today’s manufacturing systems. However, over the years manufacturing systems have evolved in response to many external drivers including the introduction of new manufacturing technologies and materials, the constant evolution of new products and the increased emphasis on quality as well as the escalating global competition and pressing need for responsiveness, agility and adaptability. These external drivers compel the realization of cognitive manufacturing, in which machining and measurement are merged together to form a more informed, more flexible, and more controlled manufacturing environment. In this way, when unforeseen changes or significant alternations happen, machining process planning systems can receive on-line measurement results, make decisions, and adjust machining operations accordingly in real-time. This paper presents a new paradigm of process planning research and outlines the way to reach cognitive manufacturing. An integrated machining and measurement process planning prototype system has been developed and tested with case studies.


Author(s):  
Wencai Wang ◽  
Derek M. Yip-Hoi

Cycle time calculation plays a major role in the design of manufacturing systems. Accurate estimates are needed to correctly determine the capacity of a line in terms of the number of machines that must be purchased. Over estimation results in excess capacity and under estimation leads to unsatisfied demand. Due to the high automation and cutting speeds of modern machining processes, cycle time calculation must consider both the timing of various machining actions and the kinematics of feed motions. This paper presents a cycle time calculation algorithm that gives accurate cycle time results by considering the effects of jerk and acceleration of the machine tool drives. The kinematic model for axis motion is based on trapezoidal acceleration profiles along the toolpaths. Based on this model, an algorithm for identifying the kinematic parameters has been developed. This algorithm has the advantage of utilizing a minimal set of axis motion data thus reducing the amount of data that must be collected from experiments by the machine tool vendor or the machine tool’s enduser. The proposed cycle time calculation algorithm has been verified in machining a V6 cylinder head on a four axis CNC machine.


Author(s):  
P G Maropoulos

This paper presents a new cutting tool selection methodology, namely the intelligent tool selection (ITS), which covers the whole spectrum of tool specification and usage in machining environments. The selection process has five distinct levels and starts by deriving a local optimum solution at the process planning level, which is progressively optimized in the wider context of the shop-floor. Initially, multiple tools are selected for each machining operation and tool lists are formed by sorting selected tools in order of preference. The second selection level provides a tooling solution for a component by considering all the operations required as well as the characteristics of the machine tool. The selected tools are then rationalized by forming a set of tools for machining a variety of components on a given machine tool at level 3 and by increasing the use of common and standard tools within a group of machines at level 4. Finally, the fifth level aims at reducing tool inventory by classifying existing tools into categories according to their usage and is also used for introducing new tools into the manufacturing system. The selection method allows the implementation of the minimal storage tooling (MST) concept, by linking the ordering of new and replacement tools to production control. ITS also uses the concept of tool resources structure (TRS), which specifies all tooling resources required for producing a component. By using the framework provided by ITS, TRS and MST it can be shown that tooling technology interfaces with diverse company functions from design and process planning to material/tool scheduling and tool management. The selection methodology results in higher utilization of tools, improved efficiency of machining processes and reduced tool inventory.


Author(s):  
Hichem Sedjelmaci ◽  
Sidi Mohammed Senouci ◽  
Nirwan Ansari ◽  
Abdelwahab Boualouache

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