Combining Dynamic Machining Feature With Function Blocks for Adaptive Machining

Abstract

Feature-based technologies are widely researched for manufacturing automation. However, in current feature models, features once defined remain constant throughout the whole manufacturing lifecycle. This static feature model is inflexible to support adaptive machining when facing frequent changes to manufacturing resources. This paper presents a new machining feature concept that facilitates responsive changes to the dynamics of machining features in 2.5/3D machining. Basic geometry information for feature construction of complex parts with various intersecting features is represented as a set of meta machining features (MMF). Optimum feature definition is generated adaptively by choosing optimum merging strategies of MMFs according to the capabilities of the selected machine tool, cutter, and cutting parameters. A composite function block for dynamic machining feature modelling is designed with Basic Machining Feature Function Block, Meta Machining Feature Extraction Function Block and Feature Interpreter Function Block. Once changes of the selected machining resources occur, they are informed as input events and machining features are then updated automatically and adaptively based on the event-driven model of function blocks. An example is provided to demonstrate the feasibility and benefits of the developed methodology.Note to Practitioners-In this paper, an important problem in most feature-based machining systems is addressed: when the selected machine tool, cutters or cutting parameters are changed due to reasons like product changeover, urgent job insertion, and broken tools, the adjustment or optimization to the machining plan is carried out based on the existing feature model. Influences of the machining resources changes to the feature model are ignored. Thus, it is impossible to get the real optimal machining result. The proposed concept of dynamic machining feature integrates the feature definition of a part to the capabilities of the selected machining resources. By applying the event-driven model of function blocks, features can be generated adaptively and automatically during the whole dynamic manufacturing lifecycle.Index Terms-Adaptive machining, dynamic feature, function block.

Proposal of a machining feature recognition method to reflect product and manufacturing information

“…Moreover, PMI has been ignored in attempts to recognize machining features (Jian et al, 2018), although the PMI is important to completely satisfy the design intent by preparing a suitable finishing operation. The machining features that have been proposed to deal with a finishing operation have not reflected the PMI (Mokhtar and Xu, 2011;Liu et al, 2016).…”

Dynamic feature based adaptive process planning for energy-efficient NC machining

“…Based on the previous research [7][8][9], a dynamic feature enabled adaptive process planning approach for complex part machining is proposed (Fig. 1).…”

Performance analysis of programmable machining strategies in milling operations of complex-shape pockets

“…W pracy [1] do analizy ilościowej strategii obróbkowych wykorzystano system CAM, zakła-dając w procesie obróbki kieszeni 2,5D jako technologicznych obiektów elementarnych (TOE) F = {f 1 , f 2 , … , f m } użycie narzędzi ze zbioru T = {t 1 , t 2 , … , t n } o średnicach d 1 > d 2 > …d n , z uwzględnieniem ograniczenia kolejności zabiegów wynikającego z zagnieżdżania cech TOE [1][2][3]5]. Na rys.…”

“…Przy wymiarach TOE równych średnicom narzędzi nie można skrócić czasu maszynowego, co pokazano w tabl. III dla czasu zabiegu t M3 i narzędzia t 5 .…”