Milling Simulation Using Dynamic Position Error Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional machining simulations fail to accurately consider dynamic errors caused by machine tool control, interpolation techniques, and structuring, leading to defects on the milling surface and lengthy calculation times.
Innovation Solution
A simulation method for milling using dynamic position errors, which projects three-axis dynamic position errors onto normal vectors on the milling surface to simulate undercutting, allowing for precision error estimation and reduced simulation time by calculating normal-vector error values and displaying undercutting information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CAD/CAM software is used to simulate machining by following numerical control codes, then the simulation can be performed with simple material removal calculation, but dynamic errors such as control errors, interpolation technique errors, or machine tool structuring errors are not taken into consideration, leading to inaccurate milling surface defects prediction
Solution Approach 1:
The simulation method is segmented into two distinct parts: (1) conventional material removal calculation based on numerical control codes, and (2) dynamic error calculation by projecting three-axis dynamic position errors onto normal vectors of the milling surface. This segmentation allows each part to be optimized independently while maintaining overall accuracy.
Solution Approach 2:
The patent introduces an intermediary computational step that projects dynamic position errors onto the normal vectors of the milling surface. This intermediary transformation converts complex multi-axis dynamic errors into scalar error values along the normal direction, which can then be directly compared with material removal depths to predict surface defects.
2Productivity
If conventional material removal calculation is performed by intersecting workpiece and cutting tool based on numerical control codes, then the calculation process is straightforward, but it costs plenty of time and does not account for dynamic factors causing simulation errors
Solution Approach 1:
The patent extracts the dynamic error calculation from the conventional simulation process and treats it as a separate, optimized component. By calculating dynamic position errors independently and projecting them onto normal vectors, the method avoids the computational burden of full three-dimensional intersection calculations while maintaining accuracy.
Solution Approach 2:
The patent changes the parameter representation from full three-dimensional tool-workpiece intersection geometry to scalar dynamic position errors projected onto normal vectors. This parameter transformation significantly reduces computational complexity while preserving the essential information needed for accurate surface defect prediction.
3Manufacturing precision
If dynamic position errors are projected onto normal vectors of milling surface, then undercutting can be simulated and defects can be identified, but additional calculation steps are required
Solution Approach 1:
The patent applies partial action by calculating dynamic error projections only at critical points on the milling surface where undercutting is most likely to occur, rather than performing exhaustive calculations across the entire surface. This selective approach maintains accuracy for defect prediction while reducing overall computation time.
Data Source
AI summary
A simulation method for milling by use of a dynamic position error includes the steps of: (a) generating a milling surface from a numerical control code, the milling surface having a plurality of grid points, the numerical control code having a position command; (b) calculating a normal vector for each of the plurality of grid points on the milling surface; (c) feeding back a position feedback of each of the plurality of grid points by the controller of the machine tool, and deriving a corresponding three-axis dynamic position error of the milling surface according to the position command and the position feedback; (d) calculating a component of the normal vector for the three-axis dynamic position error so as to obtain a normal-vector error value of the corresponding grid point; and, (e) displaying undercutting information of the normal-vector error value of the corresponding grid point on the milling surface.