Machining Simulation Using Dexels for Collision Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current machining simulation systems lack efficiency in memory performance, accuracy, and user utilization, particularly in detecting collisions between the evolving workpiece and the moving tool, especially when the tool has non-cutting parts, and fail to handle complex tool geometries such as torus or round-over tools effectively.
Innovation Solution
A computer-implemented method using dexels to represent the workpiece and cutting tool, where each dexel represents the intersection between a line and the workpiece, and computes extremity points of polylines to determine collision along the tool trajectory, allowing for precise collision detection with the workpiece, even for non-convex tools and tools with voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If classical collision detection algorithms are used, then collision detection capability is provided, but memory performance and computation efficiency deteriorate
Solution Approach 1:
The patent segments the tool trajectory into discrete steps and represents the workpiece using a voxel-based data structure divided into zones. This segmentation allows the collision detection to focus only on relevant regions at each trajectory step, dramatically reducing computation compared to classical algorithms that would analyze the entire tool trajectory and workpiece geometry simultaneously.
Solution Approach 2:
The patent introduces a new dimensional approach by using a voxel-based representation with associated zones that extend beyond the simple 3D geometry. This additional dimensional information (zones containing pre-computed collision data) enables efficient querying and reduces the computational burden during actual collision detection operations.
2Measurement precision
If detailed workpiece representation is used, then collision detection accuracy is improved, but memory usage increases
Solution Approach 1:
The patent applies local quality by associating different types of information with different zones of the voxel representation. Critical regions have more detailed zone information for accurate collision detection, while less critical regions use simplified representations. This localized detail optimizes the balance between accuracy and memory consumption.
Solution Approach 2:
The patent performs preliminary computation by pre-calculating zone information during the voxelization process. This preliminary action stores essential collision detection data in advance, eliminating the need for complex real-time computations and reducing both memory requirements during operation and computational accuracy losses.
3Measurement precision
If tool trajectory is discretized with small steps, then collision detection accuracy is improved, but computation time increases
Solution Approach 1:
The patent uses the zone dimension to store pre-computed intersection information that spans multiple trajectory steps. This allows the system to detect collisions accurately without requiring fine discretization at each step, as the zone data provides continuity information that bridges larger trajectory increments.
Solution Approach 2:
The patent maintains continuity by using zones that persist across multiple trajectory steps and contain information about material presence and tool-path intersections. This continuous zone representation allows accurate collision detection even when trajectory discretization is coarse, as the zone data fills in the gaps between discrete steps.
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
It is provided a computer-implemented method for simulating the machining of a workpiece with a cutting tool having at least one cutting part and at least one non-cutting part. The method comprises providing (S 10) a set of dexels that represents the workpiece, a trajectory of the cutting tool, and a set of meshes each representing a respective cutting part or non-cutting part of the cutting tool. And then the method comprises for each dexel computing (S20), for each mesh, the extremity points of all polylines that describe a time (h, t) diagram, and testing (S30) a collision of the cutting tool with the workpiece along the dexel based on the lower envelope of the set of all polylines. Such a method improves the simulating of the machining of a workpiece.