Machine Tool Collision Avoidance via Virtual Tool Copying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for avoiding collisions between tools and workpieces in machine tools often result in damage due to manual movement errors and require extensive computing power for simulation-based collision avoidance, increasing processing time and necessitating large safety distances.
Innovation Solution
A method that determines expected future movement setpoints to calculate a braking end arrangement of the tool, checks for overlap with a workpiece model, and slows down or stops the relative movement between the tool and workpiece to prevent collisions, eliminating the need for safety distances and reducing processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If simulation-based collision avoidance is used, then collision detection accuracy is improved, but processing time increases and computing power requirements increase
Solution Approach 1:
The patent creates a virtual copy (virtual tool) of the physical tool that moves in parallel with the real tool. This virtual copy is used for collision detection instead of running full simulations, enabling real-time detection without the computational overhead of simulating the entire machining process.
Solution Approach 2:
The patent extracts only the essential collision detection functionality from the full simulation process. By separating the virtual tool movement and collision checking from the complete machining simulation, the system achieves fast collision detection without requiring extensive computing power for full process simulation.
2Ease of operation
If manual movement control is used, then operator flexibility is improved, but collision risk increases
Solution Approach 1:
The patent implements real-time feedback by continuously monitoring the position of the virtual tool relative to the workpiece model during manual movements. When a potential collision is detected, the system immediately alerts the operator, allowing flexible manual operation while maintaining high safety through continuous monitoring.
3Reliability
If safety distances are increased, then collision avoidance is improved, but machining precision for small workpieces deteriorates
Solution Approach 1:
The patent replaces the mechanical safety distance requirement with a virtual monitoring system. The virtual tool continuously checks for potential collisions through computational geometry operations, enabling safe machining at minimal distances without the need for physical safety margins that would compromise precision work on small parts.
4Measurement precision
If complex simulations are run, then collision detection capability is improved, but device complexity increases
Solution Approach 1:
Instead of implementing complex simulation systems, the patent uses a simplified virtual copy of the tool that replicates only the necessary movement and collision detection functions. This virtual model enables effective collision avoidance while keeping the system architecture simple and computationally efficient.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The movement setpoints (ov,x-z) for controlling a relative movement between tool and workpiece are determined. An expected future movement setpoints (ov',x'-z') is determined, based on the movement command values. A braking arrangement (BA) of tool is determined, based on determined setpoints, so that geometric shape of tool describing mold model (WFM) is determined. A determination is made to check whether a tool model (WM) overlaps with a geometrical shape of workpiece, so that relative movement between tool and workpiece is stopped. Independent claims are included for the following: (1) program for preventing unwanted collision between tool and workpiece in machine tool; (2) device for controlling machine tool; and (3) machine tool.