In the last 20 years, great progress has been made in the development of non-contact methods for measuring three-dimensional objects. Main techniques that use light as a carrier of information about measured quantities play a dominant role among them. Optical measurements of a workpiece are possible thanks to the progress in microprocessor technology, visible especially in the increase in computing power of computers and the development of the field called optoelectronics.
Methods of performing optical measurements of a detail
Optical non-contact systems are based on the measurement of the reflection or scattering of light from the surface of the tested object. There are a number of optical methods for measuring the coordinates of 3D objects and many ways to qualify them. Basically they are divided into active and passive. This division is due to the fact that passive measurement techniques do not require additional artificial lighting sources, working in natural light conditions. Active methods involve additional lighting sources - incoherent (projectors, projectors, etc.) or coherent (lasers).
Precise non-contact measurements
In our Measurement Laboratory in Lublin, non-contact (optical) measurements of the measured detail are made using the Mitutoyo optical-vision system - Vision Measuring Machine QuickScope (QS) -L3017Z / AFB with an active measurement technique, which is based on the projection of various types of light structures, i.e. points, lines, stripes, grids, coded patterns.
The vision measurement system is used for the implementation of a wide range of measurement tasks. This versatility is influenced, among others, by Programmable surface lighting settings, transmitted lighting (contour lighting) and a lighting ring connected with a fiber optic cable. This allows the user to customize the QS lighting to a variety of measurement needs. The apparatus enables, among others length and angle measurement, and the entire procedure is carried out without contact. Optical measurements are the best method when making tests using traditional methods is not possible, and modern solutions increase their efficiency and accuracy.
The QS vision measurement system provides a wide range of measurement and analysis possibilities. Among the features offered are:
- magnification change,
- automatic focusing,
- repeat measurements,
- one-click edge det,
- graphical representation of measurement results,
- 48 different macro commands,
- shape search function for some of the most common features of the measured object.
The accuracy and reliability of the device used for optical measurements of a detail is also confirmed by its features and parameters, which include:
- 0.1 μm resolution and 150 mm Z axis range,
- precise lighting control - enables the correct selection of lighting for the measured surface,
- quick release system for table lock - enables immediate transition from coarse to fine feed,
- sensor type: color CCD camera,
- magnification (optical system): x200,
- Z axis measurement: Motorized with AF,
- table load: up to 20 kg.