Web-based motor testing aids real-world collaboration

Sometimes virtual reality isn't real enough. Hardware and other components must be physically tested to prove initial designs, optimize performance, ensure safe operation, and achieve future improvements. To allow real world testing at a distance, Electro Standards Laboratories (ESL, Cranston, R.I.

By Jim Montague June 1, 2001

Sometimes virtual reality isn’t real enough. Hardware and other components must be physically tested to prove initial designs, optimize performance, ensure safe operation, and achieve future improvements.

To allow real world testing at a distance, Electro Standards Laboratories (ESL, Cranston, R.I.) recently developed a collaborative test and experiment platform for motors and power systems that operates in real-time via the Internet using a standard web browser. ESL calls its platform Virtual Engineering Laboratory (VE-Lab) because it allows interactive control of actual system hardware, according to Raymond Sepe, Ph.D., ESL’s research and development vp.

Remote, fuzzy control

VE-Lab recently helped develop a 12-pole, 8-kW induction motor starter/generator and programmable load for hybrid electric vehicles. VE-Lab at ESL’s facility was connected to and established digital control of the starter/generator, while engineers at automobile manufacturers in Detroit, Mich., were able to perform real-time experiments using only a web browser.

VE-Lab’s graphical user interface (GUI) provides real-time progress data; allows local and remote operator monitoring and control of the experiment; and stores data for offline analysis. An outer-loop, fuzzy logic controller maps optimum efficiency operating points; automatically tunes the system based on a user-specified point, and communicates efficiency results to the remote site for contour mapping.

To conduct a test, VE-Lab’s digital signal processor (DSP) subsystem implements an indirect vector current controller, velocity controller, and all pulse-width modulation (PWM) timing generation. Meanwhile, the programmable load motor generates active load profiles to emulate various load and road conditions as reflected on the starter/generator.

A computer-mounted video camera allows remote, close-up viewing of experiments via the web. A GUI is present in the local laboratory computer and on the remote web computer, which enables concurrent collaborative operation of test hardware.

Architectural assist

VE-Lab’s system architecture includes a web server coded on the local computer to act as a host for web-related communications. A command processor responds to incoming orders from the server and GUI, passes commands to the fuzzy logic control system, and updates local and remote graphical interface panels.

The remote site can be physically located wherever there’s an available web connection and browser. The remote GUI panel allows remote users to monitor local user commands; operate and interact with the motor platform; and receive real-time data files from completed experiments.

Though web-related time lags aren’t exact, Dr. Sepe reports that VE-Lab has experienced delays of only a few seconds or less during several cross-continent experiments. Increased use of high-speed ISDN, cable, and DSL connections are expected to further reduce delays.

For more information, Circle 368, visit www.electrostandards.com or www.controleng.com/freeinfo , or see Jan. ’01 Motors & Drives E-News at www.controleng.com .

Jim Montague, news editor jmontague@cahners.com