Tools

Print page

Email page

Nose to the grindstone, eyes to the future

ControlDesign.com

Keywords: Computer Numeric Control, CNC, machine control, machine performance, automation, controls, Lucas Hale, ANCA Pty and operating system

As ever-increasing customer demands for better machine performance, reliability and support grind onward, one CNC machine builder is unafraid of evolving its operating system to keep its competitive edge.

IT'S A SIGN of the times in the CNC machine marketplace for machine builders and end users to see their influence contracting, and be forced to downsize their companies or go out of business entirely. So, as the demands for machine performance, reliability, and after-sales support grind onward, the companies that prosper will be those that keep their automation and controls at the forefront of machine performance. To succeed at this means having an unswerving commitment to look for and use promising software architectures.

Our company, ANCA Pty. Ltd., is a private, Australian manufacturer of CNC machines providing equipment to global, first-tier companies such as Rolls Royce, General Electric, Samsung, Boeing, Daimler-Chrysler, Caterpillar, and Volvo. ANCA’s computer-controlled grinding machines and software are found in power-train applications in the automotive industry, medical devices, specialized tool grinding, gear grinding, aerospace, and other industries. These ever-increasing customer demands require ANCA’s machines, software, automation, and processes to continue changing at a rapid pace.

“We need to support and offer the latest technologies to our customers,” says Gerard Cullen, ANCA’s CNC architect. “In an industry where performance, time and available money are crucial, ANCA actively investigates any new technology that may provide a better experience for our customers.”

Our CNC machine and its performance have evolved through an interesting sequence of operating system improvements, starting with rolling our own Assembly language code to XP Embedded with a concurrent, real-time operating system during the past five or so years.

In the Beginning
In the early 1980s, ANCA expanded by applying its high-level engineering and mathematical skills to produce complete machine tools. The company developed sophisticated CNC tool-grinding machines that combined new technology with operating simplicity.

“The first ANCA systems were built on one CPU running our own embedded code, written in Assembler, along with a basic user interface that showed machine position, and not much more,” says Cullen.

In the early '90s, needing a much better operator interface, among other things, the company moved to a hardware platform built on QNX. “This was an x86 RTOS that included, for its time, a well-developed graphical user interface,” says Dave Fisher, ANCA’s OEM business development manager. No other OS was used on the machine because we wrote our own windows for QNX, so QNX was doing the RTOS and GUI for the machine. We did this on our own motherboard with an Intel CPU. We started with QNX2 and moved to QNX4.”

Moving to Windows
In the late '90s, ANCA changed its operating system to Windows, because the QNX OS platform lacked processor support, and wasn’t keeping up with Microsoft’s Windows user interface. However, the company knew Windows alone was unable to meet the control demands of its CNC equipment. We needed the 3-D data presentation and user interface available on Windows, but had to maintain the software precision required for numerical control.

“We’d already decided on Windows, and we needed to find a product to allow us to maintain our single CPU architecture,” says Cullen. “There were two products that would allow this: INtime real-time OS that runs in parallel with Windows from TenAsys and RTX real-time extension from VenturCom (now Ardence). INtime appeared to be the more advanced both in development and features.”

Fisher remembers that both products were young in terms of clear applicability. “At the time, the two products on the market were very immature,” recalls Fisher. “INtime looked to be slightly more advanced than the other.”

At about the same time, Windows CE was making news, but ANCA’s team was certain that Windows CE wasn’t a suitable option. “We were very happy with the real-time performance of QNX, and a RTOS is required for our application,” says Fisher. “The version of QNX had become outdated, and the GUI had fallen behind. We had the option to update to a newer version on QNX, or make the change to Windows with a real-time extension.”

However, making its decision didn’t mean its transition was easy. “The RTOS and Windows NT proved to be a big challenge in the early '90s, adds Fisher. “Both products weren’t entirely stable.”

Transition to a New OS
Rewriting the operator interface of ANCA’s CNC system for Windows was a given, since ANCA was interested in using UI features of Windows that simply weren’t available from QNX. However, transferring the heart of the real-time CNC code from QNX to the INtime RTOS was a more delicate issue, given the time and effort that went into designing and validating the real-time control elements. “An unreliable CNC with an advanced 3-D interface, no matter how visually appealing, would never sell,” says Fisher.

Consequently, the team ported from QNX to INtime using an internally developed compatibility fix, referred to as “shim technology,” to maximize preservation of existing control code. “That code was up and running relatively quickly, and continues to work today,” he adds.

ANCA shipped its first product based on INtime in 2000. “The INtime API and RTOS have remained stable since the initial shipment of our Windows-based product,” says Cullen. “This allows us to concentrate on increasing the performance and complexity of our control algorithms without worrying about the stability of the underlying RTOS. This was vital since ISA support disappeared from our platforms several years ago. Translating real-time ISA hardware support code to PCI was far easier under INtime than it ever would have been under QNX. The INtime RTOS hasn’t caused any bottlenecks for ANCA, and has never prompted us to review our decision to choose INtime.”