Control Engineering Motors, Drives, & Motion Control Newsletter for December 2001
In this issue:
Function Blocks add order to motion control
Applying various, often incompatible motion control systems can be complex, confusing, and costly to users. PLCopen, Zaltbommel, Netherlands, has announced some sorely needed progress in standards development for this arena with the release of 'Function Blocks for Motion Control' specification, version 1.0, at the SPS/IPC/Drives show in Nuremberg, Germany, at the end of November 2001.
PLCopen is a vendor- and product-independent worldwide association supporting IEC 61131-3 programming standard.
The Function Blocks library-covering single-axis control and coordinated multi-axis control, among other items-has been in the works for years by PLCopen's Task Force Motion Control, according to the organization's managing director, Eelco van der Wal. Also included in the specs are examples on how to use the Function Blocks. Actually, 'version 0.99' of the spec was released for comment at last year's SPS/IPC/Drives event (CE, Dec. 1, 2000, Daily News at www.controleng.com/archives/news/2000/december/fb1201a.htm .) This was the source of 'several hundred changes,' which make the new version 1.0 of the document more useful, explains Mr. van der Wal.
Function Blocks for Motion Control go beyond the programming language. They focus, as well, on standardizing interfaces among different motion control solutions and promote more reuse of application software. PLCopen sees the result as less hardware dependent and less costly for training and support.
Further function blocks focused on specific application areas may be added to the library later. A .pdf file of the specification can be downloaded free of charge from www.plcopen.org
Propelling the Human Transporter
You just can't keep electric motors from contributing to new product developments or making the news. Hardly the sign of commodity items, as some say about motors!
Behind the main news stories about the Human Transporter-the first self-balancing, electric-powered transportation machine, from Segway LLC, Manchester, N.H.-is the motor that propels the innovative device. Supplier of the motor is Pacific Scientific, Rockford, Ill., part of Danaher Motion.
The brushless servo motor, specially developed for Segway, includes several innovations. Internal losses are reduced by use of patented, hemispherically wound stator windings, rather than typical bobbin-wound coils. For safety and performance, a set of redundant windings allows the motor to run in case the first winding fails. Pacific Scientific calls this 'effectively two completely functioning motors in one shell.' Having hemispherical windings also lends itself to motor-size reduction.
Injection molding of key motor parts and encapsulation of windings in one-step are among proprietary processes that enhance motor performance. For example, the process permits line boring of the assembly to hold air gap dimensions extra tight. Also, a proprietary feedback sensor design eliminates the need for an encoder or resolver, while retaining the motor position accuracy needed. These features are said to result in 40% more torque per unit volume than brushless servo motors of comparable size. PacSci's motor for the HT measures approximately 2.63-in. diameter x 4.5-in. long overall and delivers 2.5 horsepower (peak) from an unspecified dc supply voltage.
Three Human Transporter models will be manufactured: an i-series to handle different kinds of terrain; e-series intended for business applications with up to 75 lb cargo capacity besides the rider; and p-series for densely populated areas, indoors and out. First applications will be commercial, such as in large-scale manufacturing plants and warehousing operations, according to Segway. 'Consumer availability is planned for late 2002.'
Wireless control comes to integrated motor drives
While integrated motor and drive packages are no longer new technology, their numbers in the field have not seen rapid growth. Yet, these combination ac induction motor and inverter control products keep on innovating.
New and novel from FKI Industrial Drives, Loughborough, U.K., includes wireless remote control and parameter setting option in its FID 2000 product line. A handheld 'Data Streamer' device enables optical control using an infrared beam and a 360° prismatic receiver on the drive. One benefit is simplified setup and parameter changing in hard-to-reach installations of FID 2000. Up to 63 drive programs can be handled by one Data Streamer device, says the company.
The complete Data Streamer kit consists of a Data Streamer; an infrared Data Port (which connects to a PC COM port); and Data Store Windows application software. This arrangement allows saving drive parameters in Microsoft Windows data files and the two-way exchange of operating parameters between a drive and a PC. Also, parameters can be edited on the PC and viewed on handheld unit's liquid crystal display. Moreover, the data can be transmitted worldwide via the Internet, for example, as an aid to diagnose faults.
FID 2000 integrated motor/drives are available in the 0.75-7.5 kW (1-10 hp) power range, two motor frame sizes, and with numerous features. Full wireless control comes in addition to other usual operator interface methods, such as a two-wire keypad, serial connection (RS-485), and Profibus or DeviceNet protocols. (FKI has a U.S. office in Houston, Tex.)
For more information, visit FKI Industrial Drives.
Efficiency standards coming for small electric motors?
Electric motor efficiency standards specified in EPAct 92 (Energy Policy Act of 1992), enacted by Congress in October 1997, apply to general-purpose, three-phase ac motors in the 1-200 horsepower range. This was the initial, most promising area for energy savings. Smaller, so-called fractional hp motors (NEMA 42, 48, and 56 frame sizes) were within the scope of the legislation, but of lower priority on the agenda of the U.S. Department of Energy (DOE), the agency that enforces EPAct.
Looking at smaller electric motors has moved to a higher priority. DOE has directed Lawrence Berkeley National Laboratory (LBNL) to conduct a cost/benefit study, which DOE will use to make possible further recommendations to Congress. A joint NEMA (National Electrical Manufacturers Association, Roslyn, Va.) and SMMA (The Motor & Motion Association, Sherborn, Mass.) Task Force has been formed to provide information to LBNL and ensure appropriate industry participation in the study program.
According to Kyle Pitsor, industry director at NEMA, the study can be expected to reach DOE in early 2002. The study will be used to determine if smaller electric motors should be included under the efficiency standard. (However, motors incorporated in efficiency-regulated appliances would be excluded.) Mr. Pitsor cites three criteria that small motors need to meet to be included in the legislation:
Economic justification; and
Significant energy savings.
After results of the LBNL study are assessed, DOE will go out for comment from interested parties. A public hearing and workshop will also take place. As was the case with the initial EPAct legislation, the decision process can be lengthy. And the outcome at this point is too close to call.
Expert source on lamination steels
Second Edition of 'Lamination Steels' CD-ROM, from the Electric Motor Education and Research Foundation (EMERF, Mashpee, Mass.), comprises a major storehouse of the most up-to-date material data about lamination steel alloys used in electric motors. Materials data and product information content of the CD-ROM has nearly doubled over the first edition released earlier this year. See June 2001 E-News at www.controleng.com/ch-motors/e-news/mdmc0601.asp
The CD-ROM now contains information from six new producers (total of 11), including international sources. Other new additions are magnetization data at frequencies up to 20 kHz; data on powdered-iron core materials; and enhanced graphs and data tables. An interactive charting program for comparing core loss and magnetization curves is also included.
The disk includes an Adobe Acrobat reader needed to view the pdf file of 400-plus pages. For license fees, contact EMERF at Tel: 508/477-7405 or visit www.smma.org/emerf
Recent market studies: open control, optical encoders, step motors
Motion control (and soft logic) are singled out as prime movers for significant near-future growth of PC-based control, as detailed in 'Open Control Software (OCS) Worldwide Outlook'-a market study just issued by ARC Advisory Group, Dedham. Mass.
The two technology sectors are forecast to expand at an annual growth rate of 24% through 2006, with soft logic leading the initial 'charge.' However, ARC sees the motion control market making 'significant strides by 2006.' OCS has evolved into a viable solution for integrated, multi-function control systems, according to Dick Slansky, ARC senior analyst and author of the study. Of course, OCS applications can include a gamut of areas besides soft motion control, such as HMI, soft CNC, batch management, I/O configurators, schedulers, and, importantly, a web server.
For more information on this study visit www.arcweb.com
Two market studies have recently been completed by Motion Tech Trends, Inglewood, Calif., an international marketing and technical consultant firm serving the electric motor and motion control industries. 'North American Market for Optical Encoders 2001 & 2006' examines market size and direction during the forecast period, including specific application sectors. Also surveyed is information on major supplier companies, marketshares, technical issues (rotary vs. linear, incremental vs. absolute), and impact of new technologies on the encoder market.
'North American Market for Step Motors and Controllers 2001 & 2006' takes a similar approach in assessing the role of step motor technology among the mix of other motor alternatives. Besides a market analysis, the study points out where step motor technology is most useful, the most popular step motor sizes in the market, and most effective sales channels, among other topics.
For more information on the above reports, visit www.mttusa.com
Companies in motion
Collaboration continues in the arena of PC-based motion control. In late November 2001, Nyquist Industrial Control, Eindhoven, Netherlands, and Maxon Motor AG, Sachseln, Switzerland, agreed to jointly develop an open PC-based Motion Control system for OEM applications in the power range up to 0.4 kW. The product development seeks to integrate Nyquist's open PC-based motion control technology (NYCe product families) with Maxon's all digital servo drives. A high-speed IEEE-1394 network (FireWire) will connect NYCe motion controllers to the intelligent drives.
This move follows similar integration of Nyquist NYCe3000 multi-axis motion controllers with ServoStar 600 digital drives from Kollmorgen Seidel, Düsseldorf, Germany; Radford, Va., announced about a year ago. For more details, visit www.controleng.com/ch-motors/e-news/mdmc0101.asp
Another cooperative venture earlier in 2001 between Nyquist and Control Techniques, Newtown, Wales, U.K.; Eden Prairie, Minn., combines NYCe3000 controllers with the latter's M'Ax and MultiAx servo drives that use SLM (speed-loop motor) technology.
Recently announced, ASI Robicon, New Kensington, Pa., and Saftronics Inc., Fort Myers, Fla., are partnering on the development of a medium-voltage (MV) ac drive for underground mining applications. The project will apply Robicon's variable-frequency drives, noted for power factor and harmonic control features, in a new format. The drives' power modules will be repackaged and manufactured by Saftronics to obtain a low-profile (under 45-in. high) MV drive required in underground mining applications.
Motorola Inc., Austin, Tex., reported the sale of its five billionth 68HC05, 8-bit microcontroller (MCU)! The landmark chip went to Electrolux, a giant international manufacturer of electric-powered appliances. MCU chips make possible the remarkable intelligence and performance delivered by these end products, as well as the many consumer and industrial products that we take for granted. Most of the products involve motors and motion control systems.
The historic chip was delivered to Electrolux at a conference in Munich, Germany, in mid-October 2001. Motorola claims the distinction of being the only microcontroller manufacturer to date to have shipped such a large quantity of one product line. The 68HC05 is a general-purpose MCU family offering various memory options, voltages and speeds, I/O points, timers, and other on-chip peripherals.
For more, visit Motorola .
Control Engineering in December
Don't overlook additional information devoted to motors, drives, and motion control in each print issue of the magazine.
My cover story for December looks at the emerging technology of integrated, intelligent servo motor and control units (as well as some related step-motor-based systems). These integrated packages expand the sophistication of motors and controllers as a combined product. For some distributed applications, they offer a complete motion system solution. Technology benefits and limitations are described. An Online Extra article will follow at a later time on the Control Engineering web site. It will cover additional technology details and a sizable table of integrated, intelligent motor/control products.
This month's Up Front section mentions Ormec's (Rochester, N.Y.) 'boost' for soft motion control with its ServoWire SM line that replaces proprietary motion controller cards with PC-based control for multi-axis motion systems. Also see more on this item in Nov. 6, 2001, Daily News at www.controleng.com/archives/news/2001/November/fb1106a.htm . More is also available by visiting Ormec .
Rotary encoders from Renishaw plc, Hoffman Estates, Ill., 'star' in a sky tracking, high-accuracy servo drive for a telescope application as summarized on the Online page and detailed on our web site. Our News section includes capsule results from ARC Advisory Group's, Dedham, Mass., recent publication 'High-Power AC Drive Worldwide Outlook, Market Analysis & Report.'
December's Products & Software section includes ULT Series direct-drive, brushless motor in an unusual 'pancake' configuration from Applimotion Inc., Roseville, Calif. Choice of standard 12-, 24-, or 48-volt windings and custom windings modified at no extra cost are available. Oriental Motor USA Inc.'s, Torrance, Calif., new AlphaStep Plus has added a motion controller to the driver package of the original Alpha-Step with no increase in physical size.
SCLE presentations archived for viewing
Don't miss the SupplyChainLinkExpo web presentations available for viewing until mid-January. Four Control Engineering technology webcasts are included.