Quality and manufacturing practitioners are most familiar with the effect of variation on product quality, and this is still the focus of the quality management and Six Sigma bodies of knowledge. Other forms of variation are, however, equally important—in terms of their ability to cause what Prussian general Carl von Clausewitz called friction, a form of muda, or waste—in production control and also many service-related activities. This article shows how variation affects the latter as well as the former applications.

Anyone involved in 3D printing/additive manufacturing (AM) knows about STL file formats. Problem is—and no offense meant—STL is dumb. It’s just a large text file, generally written in ASCII programming language, defining the surface of a closed solid using a zillion triangles. For every tiny triangle, the file lists Cartesian coordinates locating its three vertices plus a normal. You can slice it up to print, but that’s it.

The National Institute of Standards and Technology (NIST) has campuses in Maryland, Colorado, South Carolina, and Hawaii. Now, I know what you’re thinking, “Hawaiian campus? How do I get a job at NIST?”

What do you think of when you think work holding? A vise, hydraulic clamps, vacuum plates, toe clamps, magnets, glue? Absolutely, but this is only half of the equation. What about the interface between these components and the machine tool? This is equally important, if not more so because it dictates the time it takes to change your work holding, which in turn has a significant effect on your spindle uptime.

A recent interview with Tadashi Nakayama, Nikon’s corporate vice president, provides insight into the strategy of the firm’s Industrial Metrology Business Unit, of which he is deputy general manager. In particular, he explained the company’s strategic focus on Quality 4.0, where digital, automated, and connected inspection enable complete process control from design all the way through to manufacture.

The core elements of a Quality 4.0-based process are the requirement for automated measurement of key features on components, as close to real-time as possible, plus the need to acquire digital results and feed them back directly to machinery to control production automatically. In this way, the quality function drives the manufacturing process, guaranteeing the best possible products.

Digital, automated, and connected inspection drives Quality 4.0

Nikon Metrology is committed to ensuring that its measuring systems lead the field in Industry 4.0, and this policy was underlined by Nakayama. At the heart of Quality 4.0 is the interconnection of inspection and production. The goal is to enable manufacturers to produce better products at lower cost, speed up their response to changes in demand, shorten time to market, and achieve an overall greater competitiveness.

“The quality function must take the lead and be the driver of the manufacturing process,” Nakayama observed. “Measurement should no longer simply be an arbiter of pass or fail, but a means of continuously monitoring and adjusting the process to ensure that every component passes. When such a policy is adopted, downtime, scrap, and costly reworking of parts become a thing of the past.”

“The quality function must take the lead and be the driver of the manufacturing process.”
—Tadashi Nakayama

Nikon intends to adopt that policy, says Nakayama. “As industry changes, Nikon Metrology will also transform itself through a constant focus on improvement and innovations. We will continue to develop metrology equipment and software to exploit technological advances to the full, and to deliver total solutions to suit customers’ specific requirements.”

He explained that the company’s strategic approach to Quality 4.0 is driving three areas: automation of inspection where possible and expedient, digitization of results, and integration of metrology data into the production line, allowing processes to be fully optimized. A Quality 4.0-based process improves efficiency and flexibility, both necessary to make companies more competitive.

Unlike Industry 3.0, which was all about mass production, Industry 4.0 includes the possibility of bringing customized goods to the market at similarly competitive prices, thus giving high-labor-cost countries a competitive edge. This cannot be achieved if products are manufactured according to Industry 3.0, where inspection is often carried out using manual gauges, after which results are recorded by hand. If parts are detected to be drifting out of tolerance, the process is tuned manually, which takes crucial time and is operator-dependent.

Inspection must be digitally integrated into the manufacturing process, so it is compatible with analysis software tools within a central database and thus able to control the process via a feedback loop. It should also be automatic if possible, although this is not always mandatory, for example, in small installations or when a factory is just starting to put quality at the center of its operation. Pragmatism and a step-by-step approach are often key when making changes in production processes.

The challenge with Quality 4.0 technology is to collect measured results in as near real-time as possible; hence, the desirability of automation to speed up the rate at which data are recorded. Additionally, automated evaluation minimizes the risk of human error when interpreting the results. Automating noncontact inspection also allows the collection of much larger amounts of data for more meaningful analysis, including trend analysis. In parallel with the flow of information on the quality of components, data from the machinery producing them are also acquired, for example, the temperature of a machine spindle or the injection pressure of a mould.

Artificial intelligence software is then employed to analyze the large amounts of information and correlate the QC data with the CAD model of the component and the machine data. In this way, it is possible to arrive at an understanding of where and why a drift from the center of a tolerance band is occurring so that it can be continuously corrected. Earlier and much better insight into production performance is the result, ensuring component accuracy, repeatability, reproducibility, and traceability, with the aim being 100-percent yield.

Quality 4.0 is happening now

Nikon Metrology has already supplied Industry 4.0-enabled QC systems to customers in Europe, Asia, and the United States. One example in the German automotive industry involves rapid, automatic measurement of the position of studs on the underbody of cars in a production line to an accuracy of 100 microns, using multiple laser radar systems. Feedback to the stud-welding robots to adjust the process is currently manual, but plans are already in place to close the loop in the near future and automate this part of the procedure as well.

A major automotive OEM in the United States has harnessed another noncontact inspection technique, Nikon Metrology’s L100 laser scanner mounted on a coordinate measuring machine (CMM), to check pre-production body-in-white panels. In the absence of the final press tooling, such pre-series panels have to be CNC-trimmed in 3D by a laser cutter. It is inspection and optimization of this final operation, previously carried out manually over a period of three days, that has been optimized by laser scanning to allow the cutter program to be updated in just four hours.

Within the automotive supply chain, electrical connectors are big business since there are an average of 2,000 connectors in every vehicle. One such manufacturer, which makes six billion plastic injection-molded connectors per year, has adopted a policy of zero-defect production. It recognizes that a faulty part can be at best an annoyance to a driver, possibly leading to costly warranty repairs or a recall program by the OEM; or at worst fatal if the connector is part of the vehicle's automatic braking system. For this application, Nikon Metrology supplied a turnkey, shop floor-inspection system with handling equipment and software that automatically loads samples into a computed tomography (CT) scanner. If a housing is out of tolerance, it is rejected and an alarm is sent to the operator, who stops and adjusts the relevant machine immediately to avoid production of scrap.

Another example is a manufacturer of low-cost chips used to track consumer goods in smart shops. This company has closed the production/QC loop to spot and correct for process drift. Nikon Metrology supplied a total solution, including an automatic wafer handler and an iNEXIV video measuring machine that inspects glass wafers and sends the data to the plant control to keep circuit-pattern dimensions within tolerance.

Future strategy: Focus on noncontact total solutions for Quality 4.0

Nikon Metrology’s strategy during the next few years will be twofold. First, from a technical perspective, collecting digital measurement data will be paramount to enable intelligent process control systems, whether they are local or in the cloud.

The company’s core competences being brought to bear in this area, according to Nakayama, are laser scanning; X-ray, including CT, which is especially suitable for high-speed, nondestructive inspection of the interiors of additively manufactured parts; analysis and control software; and the renowned, high-quality optics of its parent group. A fifth area of expertise that contributes to reliable generation of accurate measurement data is precision mechanics, such as the drives on the company's video measuring machines and large-scale laser radar scanners.

Artificial intelligence algorithms being developed by partner companies will be used increasingly to help analyze QC data, which truly are “big data” when 2D and 3D clouds of pixels and voxels generated by noncontact inspection are involved.

Second, Nikon is increasing its focus on building even stronger relationships with customers. Few in manufacturing will have missed the trend away from a supplier simply delivering a machine and leaving the user to get on with it, although amazingly it still happens. A solution approach is essential these days, and Nikon Metrology is strengthening its offering by entering into long-term business relationships with its global customers, providing support before, during, and long after installing a new process.

Future customer relationships will be fostered to elevate these to the next level. This will involve continuous dialogue not only about all aspects of the user’s installation, but also on subjects as wide-ranging as sales, marketing, and even research and development of new products.

Editor’s note: Quality Digest will be presenting an episode of Quality Digest Live from Nikon Metrology’s booth at IMTS on Tues., Sept. 11, 2018, at 11 a.m. Pacific / 2 p.m. Eastern. During the broadcast Nikon will be demonstrating their latest hardware and how it supports their Quality 4.0 focus. Mike and Dirk will also be announcing the winner of a Nikon D3400 camera. To enter for your chance to win, simply fill out the below form; you do not need to be present to claim the camera. Be sure to stop by Nikon’s booth (No. 135060) during IMTS, Sept. 10–15, 2018, in Chicago.

Register for a chance to win a Nikon D3400 camera.