Strategic Alliance Pattern Evaluation Model for Taiwan’s Machine Tool Industry: A Hierarchical DEMATEL Method

The worldwide machine tool market is anticipated to reach a value of USD 68.9 billion by 2021, from USD 65.6 billion in 2020. This projection is based on the progressive production drop within the car industry, which is the largest customer of machine devices, and supply chain disruption. The machine tool industry in Taiwan faces a severe challenge and has been unobtrusively experiencing an inner reshuffling and innovative transformation. The developing strategic alliances reflect a basic endeavor by numerous firms to improve their specialized capabilities. This study applied the DEMATEL, a suitable method for gathering group knowledge to form a structural model and visualize the casual relationship between subsystems through a casual diagram, revealing that the causal relationships between measurement criteria and the proposed model can provide a viable assessment of the alliance with satisfactory criteria that fit the decision-makers requirements, especially when the assessment criteria are various and interrelated. Financial resources were the strongest factor within the strategic behavior dimension (D1), whereas the minimize manufacturing cost was the foremost basic determinant in the cost perspective (D2). The specialists also demonstrated that obtaining dominant technology was a determinative component within organizational learning (D3). This paper offers proposals for government authorities to plan a machine tools industry strategy for Taiwan and for companies to formulate business directions for long-run advancement.

Tool-Path Planning Method For Kinematics Optimization of Blade Machining On Five-Axis Machine Tool

Planning tool-paths on free-form surfaces is a widely discussed issue. However, traditional methods of generating paths capable of meeting all the requirements of blade machining remain challenging. In this study, a new iso-parametric path-planning strategy based on a novel parameterization method combined with the conformal transformation theory was proposed. The proposed method could adapt to the curvature characteristics of the blade surface, improving the kinematic performance of the machining process, reducing multi-axis coordinated motion control complexity, and improving machining quality. The proposed method was then compared with three traditional methods. The influence of the tool-path on the kinematic performance of the machine tool was quantitatively examined based on the kinematics models of two different machine tools. A large cutting depth milling experiment was conducted to verify that kinematics optimization could improve machining quality. The proposed method provides a more reasonable path-planning approach for blade machining on a five-axis machine tool, which is of great significance in reducing the cost of blade machining and the risks of blade failure. Moreover, it is of great significance for the large-scale automated production of blades.

High-precision modeling of CNCs’ spatial errors based on screw theory

A method for establishing machine tool’s spatial error model is put forward based on screw theory, which is different from the traditional error modeling method. By analyzing the position relationship between the ideal coordinate vector and the actual coordinate vector jointly affected by linear errors and angular errors, a single-axis screw conversion matrix error expression is brought up based on screw theory. Meanwhile, the comprehensive spatial error model of the CNC machine tool is derived by considering the influence of the workpiece motion chain and the tool motion chain on the model. Further, to compensating spatial errors of CNCs, such screw theory-based model is embedded in the error compensation system by means of integration of a few specific application examples. And in order to evaluate the compensation effects, an integrated evaluation method of quantitative spatial diagonal calculation and MATLAB simulation is proposed. Application results show that the screw theory-based spatial error model of tool has a very substantial compensation effect, which makes the position error of the machine tool decreased by about 80%.