Pioneering Next-Gen Automated Metrology Solutions
Metrology News recently interviewed Dr. Kam Lau, the Founder and CEO of Automated Precision, Inc. (API) and the inventor of the Laser Tracker. Dr. Lau is widely recognized as a global pioneer in advancing dimensional metrology technology, holding numerous patents and earning acclaim for his technological innovations. His latest creation, the Dynamic 9D Ladar system, introduces a groundbreaking level of 3D scanning automation for industrial measurement applications. This innovative system is ideally suited for smart manufacturing, offering in-line, near-line, and off-line automated metrology solutions.
Q: Can you elaborate on the breakthrough technology behind API’s DYNAMIC 9D LADAR system, particularly the Optical Frequency Chirping Interferometry (OFCI) technology, and how it sets the system apart in automated production measurements?
A: Basically, laser range detection can be summarized into 3 categories: — (1) Time of Flight; (2) Amplitude or Phase Modulation (AM/FM); and (3) Optical Frequency Chirping Interferometry (OFCI). The latter is what API’s 9D LADAR adopts. It is by far the most sensitive and precise range detection technique with the ability to measure a surface at a high incidence angle and range up to 25 meters. For the 9D LADAR, the incident angle can be as high as 85° for high or low reflective surfaces.
The 9D LADAR combines advanced signal processing and parallel computation techniques executed on a hi-speed digital processor embedded inside the LADAR. No external computing processor is needed other than a laptop connecting to the LADAR via a Wi-Fi internet cable. The 9D LADAR sends out raster-scan measuring data (X, Y, Z, i, j, k, R, G and B) at a rate of 20,000 points per second. RGB are the primary colors of the scanned object captured by the iVision camera of the API LADAR.
Q: How does the 9D LADAR system replace traditional coordinate measuring machines (CMM) in terms of efficiency and accuracy, and what industries, besides automotive, and aerospace manufacturing, can benefit from this innovation?
A: Smaller CMMs of less than a 1-meter cubic measuring capability still have the advantage of higher precision compared to the API 9D LADAR. For part sizes beyond a meter or inspection tasks requiring higher throughput and higher automation, the 9D LADAR is a better choice. At 20,000 points per second, non-contact measuring and the ability to measure deep into a hole to capture the details inside, no other measuring technique or system can compete with the 9D LADAR.
Automotive and aerospace manufacturers are certainly two of the major industries which 9D LADAR sees the largest application. Industries such as the wind energy, nuclear energy, shipyard, iron mills, gas turbine manufacturers, industries involving in building large and precision structures and machines, and industries with operational safety concern requiring non-contact and fully automated operations, 9D LADAR can the system of choice.
Q: The API 9D LADAR system boasts impressive data processing capabilities, such as 20,000 points/second and 50 lines/second. How does this high-speed data acquisition contribute to the system’s effectiveness in capturing both dimensional and surface geometry data?
A: The Dynamic 9D LADAR captures 9D (X, Y, Z, i, j, k, R, G, B) information at an impressive rate of 20,000 points per second, which is about 100X faster than any other raster scanning system, and with an effective measuring range of 0.75 to 25 meters. Data density can be as high as 0.05mm spacing to 5 mm per point.
Figure on the left below represents the 3D geometric point cloud captured by the 9D LADAR. The Figure on the right shows the same point cloud overlaid with the RGB data. As a result, instead of the mono-color typically seen with 3D geometric point cloud, the RGB overlay brings more realistic information and identification of the part measured.
It should also be noted that the artifact in the picture (below) is a swan glass crystal. For the API 9D LADAR, picking up data reflected off a glass object is common, indicating the ability of the LADAR in accepting very low returning signal.
Q: The iVision smart camera system is highlighted as part of the 9D LADAR’s features. How does this system contribute to automated scan path planning and provide instant part visualization for measurement operations?
A: The iVision system provides an intuitive way to plan paths. Based on an 8/12 meg-pixel RGB camera, operators can zoom-in and select any region directly from the live video stream. Even large parts which are too large to scan in a single pass can be scanned using the API MeasurePro operating software to create continuous ‘contour scan’ which will automatically segment the path. Additionally, this path planning process can be achieved remotely with an external PC through a Wi-Fi connecting to the on-board digitizer of the LADAR.
Q: The original Laser Radar technology faced challenges such as slow speeds and limited accuracies due to surface reflectivity and incident angles. How does the new LADAR technology overcome these challenges using 20kHz speed laser chirping and what impact does it have on data acquisition rates?
A: The LADAR’s superior incident angle of 85+ degrees and dynamic range capabilities allow it to scan large or complicated objects with fewer move locations, reducing the time spent on positioning and requalifying the orientations of the LADAR. The 20,000 points per second data rate enables high resolution and more accurate measuring of surface features or features even deep inside a hole.
The figure (below) is an example of the API 9D LADAR’s super capability of measuring the inside diameters of a 1.3-meter-long tube with precision and repeatability to better than 0.010 mm. The angle of incident to the far end of the tube is about 87 degrees with both the signal and accuracy integrities maintained.
Q: In the context of Quality 5.0 applications how will the API 9D Ladar innovation contribute to improving measurement throughput and productivity, especially in automotive and aerospace applications?
A: Quality 5.0 refers to the next evolution of quality management practices which emphasizes a proactive approach to quality control using advanced technology tools like the API 9D LADAR. As a non-contact dimensional measuring instrument, 9D LADAR offers the precision speed, accuracy, and compactness to measure key features of a body-in-white in automotive or fuselage sections in aerospace assembly. Being proactive with actual data measured allows next step processes in the assembly to improve the quality. Hanging doors by the automated robot referencing actual feature data from an individual body-in-white IMPROVES flush and gap in the final door assembly. Actual gap measurements in the full 360-degree measurement of the fuselage fastening positions IMPROVES less shimming and rework in assembly. API 9D LADAR clearly supports proactive process quality and ease of integration in advanced and highly automated manufacturing facilities where Quality 5.0 is required.
For more information: www.apimetrology.com
