Intensity-Based Registration With Voxel-Based Computer-Aided Manufacturing for Adaptive Machining

Abstract

This paper presents a novel application of intensity-based volume registration to manufacturing using voxel-based computer-aided manufacturing (CAM) models. The introduced techniques are presented in the context of machining irregularly shaped materials by integrating volumetric imaging feedback to computer numerical control (CNC) machine tools. This requires a comparison and alignment to be performed in the software to geometrically “fit” the source design model inside a rendered starting material. The requirements differ from many typical registration applications in that the workpiece will necessarily be larger (i.e., greater in volume) than the desired final computer-aided design (CAD) file. Therefore, models need to be aligned for toolpath generation to workpiece counterparts that have been either volumetrically offset or contain additional material/volume. Intensity-based registrations are unique in that they consider only the voxel values over the entire volume. Although advancements in medical imaging have produced efficient, robust voxel registration algorithms, these techniques have not yet been applied to manufacturing. This research introduces the use of maximization of mutual information (MMI) for voxel-based CAM to drive an alignment registration for systems integrating imaging technology. A simple but novel method, which the authors have named minimization of distance variance (MDV), is also introduced. This minimizes the variance between voxel intensities to demonstrate the design of a similarity metric for a simple case in machining rough castings.

Digital Twins-Based Smart Design and Control of Ultra-Precision Machining: A Review

“…Accurately capture and process the in situ spatial information from a controller Improve the accuracy of voxel models of the workpiece-in-process [18][19][20][21][22] Process planning Ensure the accuracy of positioning, tool path planning, and efficiency for blend features Precise micro process planning for generating machining instructions [23][24][25][26] Process monitoring High cost and high probability of damage to UPM system Improve product quality under the dynamic change of the machining condition [27][28][29][30] Vibration control Call for multi-physics modeling techniques as well as real-time controlling.…”

“…Collins [18] presents a voxel volume model registration method based on registering and machining near-net-shape structures and rough castings. Collins et al [19] further presented intensity-based volume registration for irregularly shaped materials machining by integrating volumetric imaging feedback about the voxel model to machine tools. An intensity-based similarity metric, together with a metaheuristic registration algorithm, is designed based on Euclidean distance transformation and variance calculation.…”