Optical Workpiece Origin Detection Using Backlit Through-Hole Alignment
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Solution Overview
Problem
Existing optical sensors in numerically controlled machine tools face challenges in accurately identifying the part origin position when there is insufficient contrast between the foreground and background, leading to erroneous measurements and quality issues in manufactured parts.
Innovation Solution
A method and system that involves positioning a part with a through hole opposite a through orifice in the machine tool's enclosure, where a light source emits radiation through the hole and orifice to an optical measuring device, allowing precise identification of the part origin by highlighting the reference object, such as the center of the hole, thereby ensuring accurate tool trajectory determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensors are used to identify the part origin position based on contrast differences between foreground and background surfaces, then the measurement precision is improved under normal conditions, but the reliability deteriorates when contrast differences are insufficient
Solution Approach 1:
A light source is introduced as an intermediary element positioned behind the part to actively illuminate the background surface. This mediator creates a controlled contrast difference between the foreground (part surface) and background (support surface) by emitting light that passes through the transparent or translucent support, enabling the optical sensor to reliably distinguish the part origin position even when natural contrast is insufficient
Solution Approach 2:
The illumination parameters are changed from passive ambient light to active controlled light emission. By adjusting the light source intensity, position, and spectral characteristics, the contrast difference between foreground and background can be optimized to ensure reliable optical sensing under various manufacturing conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures precise identification of the part origin in all circumstances, enhancing the accuracy of tool movements and ensuring compliance with quality requirements by providing a robust method for determining the part origin position, even when contrast differences are insufficient.
Implementation Method 1
lighting by a light source, so as to emit light radiation from the support, towards an optical measuring device arranged in the enclosure of the machine tool, through the hole and the orifice
Data Source
Figure 1
AI summary
The invention relates to a method for determining the position of a workpiece (100) in an orthonormal coordinate system based on the structure of a numerically controlled machine tool in order to determine the trajectory of a tool (20) for performing an operation on said workpiece (100). The method comprises the following steps: - holding the workpiece (100) in position on a support (110) fixed within the enclosure of said machine tool, so as to align a through hole (101) in the workpiece (100) with a through orifice (111) in the support (110), said hole (101) opening entirely into said orifice (111); - illuminating the workpiece with a light source (120) so as to emit light from the support (110) to an optical measuring device (40) arranged within the machine tool enclosure, through the hole (101) and the orifice (111); - reading the workpiece (100) by the optical measuring device (40),so that the latter determines the position of said part (100) in the orthonormal coordinate system.