Summer 2006, Vol. 3, Issue 2

CHIA: Handy NWC inspection tool

Over the past 7 years, two Applied Technologies researchers have developed six model-based technologies — three inspection programs and three tooling advisors — that enable users to save significant time and money by modernizing tool-design operations and simplifying the generation of complex inspection data. Before model-based technologies, inspectors had to rely on printed drawings to examine manufactured items. Additionally, tooling was laboriously made, sometimes taking nearly 2 months from beginning calculations to solid models.

Modeling's advantages include the capacity to capture and archive the knowledge of Y‑12 experts.

All six model-based programs work with the standard computer-aided-design program Pro/Engineer. CHIA (Computerized Hirsute Inspection Algorithm), an inspection tool originally developed for the Y‑12 National Security Complex, is now used by Los Alamos National Laboratory and the Kansas City Plant. CHIA automates the collection of surface coordinates and their corresponding normal vectors on any Pro/E solid model and outputs those data for a variety of subsequent uses. In one instance, CHIA users at LANL generated the coordinates and vectors from a solid model, imported the data into a programming application, inspected the object on a coordinate measuring machine, and analyzed the data — all in a hour.

Although LANL and KCP are the primary users of CHIA, its creators believe more will follow.

The program can produce inspection points on any CMM that requires points and normal vectors, and most CMMs in the weapons complex work that way. CHIA can inspect objects that have unusual or complex shapes, which are not always easy to obtain from a printed drawing. Even the automobile and aerospace industries could benefit from adopting the program, the developers maintained.

In addition to CHIA, the Contour Inspection Programming System generates an entire inspection program but is executable on fewer machines. The Probe Cluster Wizard shows shop-floor workers how an inspection probe should be reassembled to accommodate each new inspection item.

Users of the three tooling programs—the casting, forming and fixture advisors — start with the item they want to manufacture and reverse engineer the tooling from that. Knowledge about casting, press forming and machining fixtures is captured and rolled into the modeling process.

Despite modeling's increasing influence, print drawings remain the approval basis at Y‑12. The researchers hope that practice ends and the site embraces a completely model-based approach. In the meantime, their next goal is to link some of the model-based programs — currently “islands of automation” — so the processes can realize their full potential.

Table of contents