Whether it’s a cherry red convertible bought in the fit of midlife-crisis angst or a sensible commuter car that doubles as the family grocery getter, automobile buyers everywhere appreciate the smooth lines of their sedans, pickup trucks and sports cars.
Similar considerations are given to passenger planes, where fuel economy and flight characteristics depend on accurate, defect-free fuselages, and even garden tractors, which as everyone knows must be sexy as well as functional.
These are just a few of the products measured with 3-D scanning systems, which use little more than light, lenses and some darned-clever software to measure a component’s shape and determine whether it meets the required tolerances.
White light scanning systems can capture millions of data points within a fraction of a second, increasing throughput and reducing the cost of quality.
The next level
One such scanning system comes from ABB Robotics. In February of 2017, the robotics manufacturer announced its acquisition of 3-D white light scanning startup NUB3D. In a press release, Sami Atiya, ABB’s robotics and motion division president, said the move was one more step toward the factory of the future.
“As our customers’ automation processes become more advanced and production cycles shorten, the ability to efficiently automate quality inspections becomes a compelling competitive advantage,” he said. “Combining robotics and software is pivotal in implementing digitalization and expanding ABB Ability as a key driver of our Next Level strategy.”
Mark Oxlade, market development manager for welding and cutting at ABB Robotics, says the partnership with NUB3D has opened the door for faster, more accurate measurement of a variety of parts used by automotive and consumer product industries. By mounting one of NUB3D’s white light scanners to the business end of a 6-axis robot, ABB customers can quickly scan a part, compare the results to its CAD model and assess the quality of the part based on the data provided.
ABB’s robotic inspection systems are fast, accurate and easy to implement.
A million points of light
“The sensor technology rapidly records and compares highly detailed geometric and surface data with digital CAD models, enabling the automated inspection of manufactured parts and pieces,” Oxlade says. “This helps factories to reduce cycle times while raising quality and reducing the risk of quality control errors.”
Because up to 5 million points are captured in each quarter-second scan and because the NUB3D scanner is accurate to “within microns,” the ABB system is able to identify unfavorable quality trends at an earlier stage of production compared to existing methods, greatly reducing the chance of expensive scrap later on.
By combining robots and white light scanning systems, metrologists can achieve a best-of-both-worlds measurement solution.
How does it work? The measuring process begins by acquiring a 3-D model of the part. The operator imports the file into a virtual cell environment within ABB’s RobotStudio software, after which the robot’s measurement path is generated, the program is sent back to the robot and each position is digitized, thereby acquiring a point cloud.
This point cloud is converted into a template file for use in PolyWorks Inspector, a universal 3-D metrology software package from InnovMetric that compares the point cloud to the associated robot path. Using the part’s 3-D model as the baseline, variance from nominal can then be calculated.
“This system represents the future of flexible manufacturing, enabling a high level of automation with advanced data analysis that can be used to optimize production processes,” Oxlade notes. “This helps manufacturers improve quality and productivity while accommodating greater product variation and customization in smaller lots.”
Hexagon’s Blaze 600A offers rapid data acquisition through a combination of high-resolution digital imaging and advanced projection technologies.
Into the light
Metrology provider Hexagon Mfg. Intelligence is another company working in the white light arena. According to Amir Grinboim, technical program manager of Hexagon Integrated Solutions and a white light system (WLS) expert, because of their speed and accuracy, a WLS is suitable for a broad array of measurement needs, but especially so in less than optimal factory environments.
“Automotive customers at stamping facilities, for example, can rely on the WLS platform in both manual and automated configurations to measure parts near working press lines,” he says. “Not only do the environmental conditions have no effect on the measurement results, but our customers can increase throughput by measuring directly where the manufacturing takes place.”
Hexagon’s Blaze 600A offers rapid data acquisition through a combination of high-resolution digital imaging and advanced projection technologies.
One of Hexagon’s aerospace customers uses the company’s WLS systems to measure wing structures. Grinboim explains: Because the acquisition process is so fast, they can use the system on one side of the plane while mechanics and electricians are working on the other. There’s no need to stop production to achieve an accurate scan. This attribute is especially appealing to stamping houses and other manufacturers with heavy machinery where vibration can negatively impact the measuring process. In addition, dust and smoke have no effect on system accuracy – worst case, you might need to stop and clean the lens periodically.
The system Grinboim is referring to is the WLS400, a portable, non-contact 3-D scanning system that uses blue light LED illumination to capture millions of data points in as little as 10 milliseconds. The company also offers its qFlash, a compact, entry level scanning system used widely in the automotive industry, as well as the Blaze 600, a versatile sensor and optical measurement system first introduced in 2017 that combines multiple data acquisition modes to provide the ability to adapt the acquisition mode to the measurement task with a button click.
Depending on the application and equipment configuration, these systems can be hand-held, mounted to a movable arm or attached to a robot with Flexible Measurement Cell (FMC) platform that offers a modular and scalable off-the-shelf automated solution. Device calibration is achieved via a calibration artifact. Temperature changes greater than 3 degrees C are identified automatically, whereupon the system raises its virtual hand and tells the operator it’s time to recalibrate, a process that according to Grinboim “takes less than 2 min. to perform.”
“The fact that all of the sensor platforms can be used in both manual and automated modes enables our customers to use them as a single platform for multiple tasks in the development process,” he says. “They can start with a manual sensor for root cause analysis or process tuning and use the same sensor for process or production control further along in the manufacturing process.”
White or not?
If you’re wondering right now about white light versus blue, Grinboim can explain.
“Sometime around 2010, we along with most of the industry moved to blue light LED-based illumination,” he says. “We kept the name ‘white light’ because that’s how these systems are known, but yes, they’re actually blue. Besides being a stronger light source than white light, the shorter wavelength makes it much easier to filter out ambient light, providing more robust scanning capabilities.”
Automotive sheet metal parts and bodies-in-white automobile chassis are ideal applications for these systems, but there’s also tool and die, large castings and forgings, plastic parts and many other applications that can benefit. And reflective surfaces like chrome or shiny black paint that have traditionally caused problems for optical systems such as these are just another super-fast and accurate scan for Grinboim’s equipment.
“Machined or highly reflective parts have been challenging in the past, but the qFlash can reliably pick up 60 to 70 percent of all surfaces; the WLS-series and the new Blaze are even better,” Grinboim says. “Best of all, you can set the part in a simple holding fixture or even leave it where it is on the floor or assembly line to measure it – there’s no need for expensive, metrology-grade fixtures. It’s just a great solution for a lot of applications.”
