Technology changes like a New York or London minute, or sometimes at laser speed. The new wave of digital holographic imaging technology developed at the University of Michigan in the US is emerging as the fastest approach to accurate, rapid testing for the biggest, costliest and most complicated vehicle parts – engine, transmission and chassis components.

Disciples of high-definition digital holographic metrology tout it as the next big thing of digital manufacturing, a game-changer that could revolutionise the car-making process. Coherix of Ann Arbor, Michigan, has been in the vanguard of advancing the technology since 2003. Coherix CEO and Chairman Dwight Carlson describes digital holographic imaging technology as a “disruptive innovation” that can separate the winners from the pack. Its optical-based inspection systems measure production line quality and improve the speed and precision with which component quality is measured. “Major product breakthroughs are always preceded by a major breakthrough in manufacturing process capabilities. And these are preceded by major breakthroughs in metrology,” Carlson observes. “If you can measure it, you can make it; if you can measure it better, you can design and make it better.”

Dramatic reduction in defects
Before forming Coherix, Carlson was CEO of Perceptron, which developed laser-based metrology for automotive customers. The new holography tools will help manufacturers dramatically reduce defects, improve warranty and performance by achieving tolerance levels of two microns or less, Coherix officials say. Just how tiny is that? A micron equals one-millionth of a metre (0.000039 of an inch). Automotive engines, for example, are designed with production variances of 12 microns or more.

Coherix’s ShaPix, for example, is a surface data tool that uses tunable wavelength lasers that illuminate surface areas. The tool produces 3D images of objects being checked, when paired with optical equipment and software. The 3D images come out in three minutes or less, far more powerful than other traditional coordinate measuring machines Game-changing digital holography.

Coherix ShaPix (share pix) surface detective performs high definition 3D measuring of machines and other precision surfaces for all surface dimensional characteristics including flatness, waviness, hole patterns and parallelism of surfaces which can take several hours or more, depending on complexity, and only capture individual points on components.

Butch Dyer, President of the PEMAlliance says a long-term goal of digital holography is to reduce OEM powertrain operating and warranty costs by 30 per cent or more. “The introduction of highdefi nition imaging to monitor machining centre quality will enable manufacturers to dramatically improve launch times and increase operating effi ciencies by achieving tolerance levels of two microns or less,” he said in a statement. The PEMAlliance (Powertrain Engineering and Manufacturing) is a newly formed Michigan-based powertrain manufacturing consortium.

‘Changes the ballgame’
High-tech consultants call the digital holographic technology ground-breaking and transforming. “Analog measuring takes data one point at a time. Digital holographic imaging changes the ballgame. It takes and measures one million points at a time. It’s so big it’s mind-boggling,” says Tom Weber, industry analyst and consultant to major automakers and suppliers.

Weber says the holographic metrology industry is at the “three blind men and elephant stage” and still is “trying to fi gure out what to do with all this digital capability. It may take a while, but everyone wants to go faster.” So far adoption of the technology is in its infancy, but Weber predicts growth as synergies build.

For now, Coherix is working with companies such as Ford, General Motors, Chrysler, Bosch and TRW to perfect the technology. “Digital holographic technology allows you to take a lot more accurate measurements and these are made more quickly. You don’t have to do (other) testing,” says Tony Hain, Associate Provost, Graduate Studies at Kettering University, an engineering college in Flint, Michigan, closely aligned with GM.

Evidence is mounting that when digital holography is employed “it makes dramatic gains in processes, eliminates waste and cost and overall warranty costs go way down. Quality problems go out the door. A lot of manufacturing problems begin to disappear,” Hain said. Coherix is part of the newly formed PEMAlliance that received a $4.9 million federal grant in September 2007 to develop engine technology to potentially save US carmakers more than $1 billion annually, Dyer said. So far, the consortium involves domestic manufacturers.

In addition to Coherix, members of the alliance include Chrysler, General Motors, Ford, Harley-Davidson, Kettering University, Rousch Enterprises and the University of Michigan