Investigation on multi-body dynamics based approach to the toolpath generation for ultraprecision machining of freeform surfaces

Abstract

This article presents an innovative approach to toolpath generation for ultraprecision machining of freeform optic surfaces based on the principle of Automatic Dynamics Analysis of Mechanical Systems. As components with freeform surfaces often have non-rotational symmetry, there are potential challenges facing their ultraprecision machining through single-point diamond turning, such as the projected points in complex large sag surfaces, which likely find it difficult to communicate with the control system and, thus, do not perform successfully. In ultraprecision machining, to achieve the highest performance in freeform surface resolution, the factors of dynamics, material and mechanical stiffness, frictions, tooling and accuracy of the servo component should be considered. The investigation is focused on an integrated approach and the associated scientific understanding of precision engineering design, ultraprecision machining and metrology of freeform surfaces as well as their application perspective. In this approach, the toolpath for very complex freeform surfaces can be generated using the Newton–Raphson method to solve the kinematics and dynamics equations of motion. The effect of friction and contact force are also investigated for accurate toolpath curve generation. Moreover, the Gear stiff (GSTIFF)/ Wielenga stiff (WSTIFF) integrator for solving the non-linear equations of motion is employed, and the result shows the time step size, playing a critical role in generating toolpath curves with a higher accuracy and resolution.

Monitoring and Predicting the Surface Generation and Surface Roughness in Ultraprecision Machining: A Critical Review

“…UPM is also called diamond turning, where a single crystal diamond tool is employed, and by which a nanometric surface finish can be obtained; the key components of a diamond turning system are shown in Figure 2. Since the latter half of the 1990s [11], there has been a large amount of research on UPM, also called diamond turning is typically a single point turning process, which emerged as a promising technology used for optics manufacturing, including high value components such as aluminum mirrors, aspheric optics, head-up display devices, and ophthalmic freeform surfaces [12]. UPM is used for machining different kinds of materials that are difficult to machine using conventional techniques and materials such as silicon, germanium, chalcogenides, and others.…”

Financial Accounting Measurement Model Based on Numerical Analysis of Rigid Normal Differential Equation and Rigid Functional Equation

“…If the function value on the node is given in advance, the expansion coefficient in the expression can be obtained by the fast Fourier transform [6]. The calculated amount is O(N log N).…”

Development of a Surface Roughness Prediction Model for Slow Tool Servo Turning Machining

“…Slow tool servo turning technology can achieve repeated machining of complex optical surface components with submicron or higher surface accuracy, nanometer surface roughness without treatment after machining, and high machining efficiency. It provides a new way to accurately machine complex optical surfaces with high efficiency [5][6][7].…”