Multi-Axis Servo Amps Revamp Automation Design

April 28, 2003

This all-digital motion-control architecture cuts costs up to 50% and makes designs easier with a library of software building blocks.

Roger Allan

Fundamentally changing the way engineers design automation systems, Copley Controls' family of network-compatible all-digital servo amplifiers suit multi-axis motion control, slash system cost, and minimize complexity. The company believes its Accelnet technology, the basis of these amplifiers, is its most significant creation in 20 years of motion-control innovation. The technology is allied with the industry-standard CANopen networking protocol. The amplifiers work with freely available software building blocks from the Copley Motion Library (CML).

The Accelnet line's five versions operate from 55 V at 8 A peak to 180 V at 20 A peak. They provide sinusoidally commuted motor drive plus field-oriented motor control. Designed with solderless power and signal connections, they're built on pc-board-mounting packages that measure just 2.62 by 4.05 by 0.98 in. Communication is over a two-wire control-area network (CAN) bus.

Advanced carrier-cancellation modulation is used for maximum zero-crossing linearity as well as for ultra-low ripple current that occurs at twice the carrier pulse-width modulation frequency. Ripple frequency is 28 kHz. Current-loop bandwidth is 2.5 kHz. Each amplifier provides a 14-kHz current-loop update rate (17.4 µs) and a position and velocity loop update rate of 3.5 kHz (286 µs).

Accelnet servo amplifiers, available from stock up to four weeks, cost from $330 each in one- to nine-unit quantities based on current and voltage ratings.

Copley Controls Corp.
www.copleycontrols.com

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About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.