SCG-190 testing equipment
The SCG-190 inspection equipment is a system equipped with a high-resolution camera, light source, lens, and non-contact 3D probe and its controller. It combines a vision system and a confocal spectral system to locate the spatial position of the product. Through multispectral probe scanning, the inspection angle range is greatly improved, and stitching technology is used to completely capture and display the product's contour. It also employs EtherCAT bus control and PDO data synchronization with position, ultimately creating an inspection system with high positioning and measurement accuracy, a large inspection angle, a wide measurement range, and high inspection speed. For 3D glass contour and shape measurement, the SCG-190 inspection system is an optimal choice, as shown in Figure 1.
Figure 1. SCG-190 testing system machine.
Traditional contact measurement
Figure 2 Traditional contact measuring instruments
Contact type: Three-dimensional probe contact measurement, which is very likely to damage the product;
Speed: Measuring a single contour takes more than three minutes; slow speed and long time.
Accuracy: Contact damage to the product reduces data accuracy;
Traditional contact measuring instruments are shown in Figure 2.
Non-contact measurement
Sensor advantages
Non-contact testing: It does not come into direct contact with the product and does not cause any damage to the product; the SCG-190 testing equipment collects the light waves reflected from the product surface through a spectral system and analyzes them to obtain product surface information. It can obtain product surface data without direct contact with the product, ensuring that the product is not damaged in any way during the testing process.
High frequency: The highest sampling frequency is 50kHz; a high sampling rate can more accurately reflect the surface condition of the product.
Even the most subtle changes can be clearly shown and accurately identified.
High speed: rapid visual positioning, with a positioning time of less than 10 seconds; high-resolution cameras with over 5 megapixels can distinguish details in high definition.
Quickly locate the product's position and coordinates along the product's edge.
High versatility: No material requirements (including transparent objects); all objects reflect light to some extent, including transparent objects.
Spectroscopic systems can sense weak light waves to obtain data about a product's surface. They are applicable to products of any material and color.
High precision: resolution of 0.1µm in the Z-axis direction; the high-precision spectral system can distinguish heights of 0.1µm, ensuring detection quality.
Large detection range: It can detect within the range of 1mm to 12mm; different models of spectral detectors have different detection ranges, and the maximum range of 12mm can meet the needs of almost all products.
Environment: Can work in adverse environments such as high temperature, high radiation, darkness, and humidity;
System advantages
High-precision motion: The motion control system adopts a fully closed-loop control system, with a motion accuracy within 0.001mm;
High productivity: visual positioning time is less than 10 seconds, and single curve scanning time is less than 10 seconds.
High real-time performance: It adopts EtherCAT bus control and uses PDO synchronization function to ensure that the position and probe data are matched one-to-one;
High compatibility: Compatible with all devices that support EtherCAT bus control;
Large angle: The scanning angle reaches ±60 degrees, enabling the detection of flatness, arc radius, and irregular arc contours;
Simple to operate: one-click automatic detection, automatic determination of product qualification, one-click automatic data analysis and export;
Modular design: Design modules can be added or removed at any time to adapt to user needs;
Based on these advantages, the SCG-190 inspection system has unparalleled advantages in measuring the thickness and profile of glass.
Application areas
Product structure and shape analysis;
Surface features of an object;
Three-dimensional height and thickness detection and analysis;
Spatial econometrics analysis;
3D glass surface contour detection
Detection methods and procedures
I. Establish a three-dimensional reference coordinate system (X, Y, Z):
Figure 3 Figure 4
Explanation: As shown in Figure 3, the product is positioned using spectral or visual methods. The PLC controls the motion axis to enable the camera to accurately capture images at positions a, b, c, d, e, and f. The software automatically searches for the product edge to establish the X and Y coordinate systems and the origin coordinates. Then, the spectral probe collects data at positions 1, 2, 3, and 4 to establish the Z coordinate origin. The visual positioning imaging effect is shown in Figure 4.
II. Determine the scanning location
Figure 5 Figure 6
Note: Mobile phone curved screens are generally divided into dual-curved screens and quad-curved screens. The scanning position of a dual-curved screen is shown in Figure 5, and the scanning position of a quad-curved screen is shown in Figure 6. Before scanning, the spectral coordinate system, visual coordinate system, and axial coordinate system must be established and unified into the same coordinate system. Based on the customer's requirements, the scanning position of the spectral probe must be accurately controlled to match the customer's required position.
III. Scanning Method
The 3D curved surface of the quad-curved screen has a large curvature, and the detection angle of the spectral probe is small, so it needs to cover the entire curved surface. The detection method is shown in Figures 7 and 8.
Figure 7 Figure 8
Three spectra are mounted on the same straight line. The left spectrum is responsible for scanning the left curved surface, the middle spectrum is responsible for scanning the back curved surface, and the right spectrum is responsible for scanning the right curved surface. During scanning, all three move in the same direction at the same time. Each spectrum scans within its own scanning range and acquires data. Then, the three curves are fitted into a single curve using a stitching technique.
Spectral scanning graphics
Figure 9 Figure 10
Figure 11
The software can display the graph of a single spectral scan, as shown in Figure 9. The blue curve represents the data acquired from the left spectrum, the red spectrum represents the curve data acquired from the middle spectrum, and the green curve represents the data acquired from the right spectrum. It can also display the graph of multiple spectral scans stitched together, as shown in Figure 10. If multiple data points are scanned, all the data can be fitted into a 3D model to vividly reflect the outline of the object being measured, as shown in Figure 11.
Data Validation
Based on international standards for contour accuracy, the curve scanned using the above method is compared with the curve data measured at a specific location by a 3D measuring device.
Machine parameter table
