Control Engineering Motors, Drives, & Motion Control Newsletter for September 2000
In this issue:
Don't overlook servo-pneumatic linear motion control
Servo-pneumatic linear motion control can add to an engineer's toolbox of solutions, despite the 'foster-child' image of pneumatics that's due to the compressibility of air. Recent developments make the difference.
One example is a rodless cylinder with velocity control from Tol-O-Matic Inc. (Hamel, Minn.) that combines pneumatics, electronic control-with encoder feedback-and a proportional magnetorheological (MR) fluid brake to produce accurate positioning at lower cost than electromechanical systems. Repeatable positioning capability of new PrecisionAire actuators is given as
Simple yet accurate control of 'bang-band' cylinders is obtained with PrecisionAire actuators by controlling current to the magnetorheological fluid brake instead of airflow to the cylinder. Only standard pneumatic valves are requires (two 2-position type or one 3-position type valve, with under 20 msec solenoid response time). The MR fluid brake comes from partner-company, Lord Corp. , Materials Division (Cary, S.C.). MR fluids contain fine magnetic particles and have the ability to rapidly change their apparent viscosity under a varying magnetic field. For more on MR fluid technology, see Control Engineering , June 1999, p. 91.
The electronic controller is the key system element, according to Tol-O-Matic vp of marketing, John Studer. The DSP-based controller offers autotuning, built-in motion profiles, and a Microsoft Windows graphical user interface for setup and programming. PrecisionAire actuators are available in 1.0- or 1.5-in. bore sizes, with respective thrust loads of 60 lb and 141 lb (at 80 psi) and speeds up to 100 in./sec. A 36-in. stroke (1.0-in. bore) unit is priced at $2,800.
Need economical 6-axis motion sensing?
Do you have a need to measure X-, Y-, and Z-axis accelerations, plus roll-, pitch-, and yaw-axis angular rates using a single device? Then, a six degrees of freedom (6 DOF) inertial measurement unit (IMU) from Crossbow Technology Inc. (San Jose, Calif.) may be the answer to your testing needs for vehicle systems or components, and other dynamic machine products. DMU-H6X makes 6 DOF measurements without the need for calibration. Bias stability of the unit is &10 mG for the accelerometers and &
Hollow-shaft 'equivalent' for linear motors
LinMot (Rogers, Minn.) has introduced a hollow-slider version of its industrial linear motor. It's the linear 'equivalent' of hollow shaft design found in rotary motors to optimize space for access of cables and connections. LinMot P Linear Motor allows direct access for wires, tubing, etc. down the motor's center axis. The slider's outside diameter (37 mm) remains the same as in the standard linear motor. LinMotP is a tubular, direct-drive linear motor that comes with built-in bearings and sensors. LinMot is part of the $4-billion Sulzer Corp. of Winterthur, Switzerland.
Companies in motion
Eaton Corp.'s (Cleveland, O.) Cutler-Hammer Group and Vaasa Control (Vaasa, Finland) have announced a joint venture for the manufacture and marketing of low-voltage, variable-frequency drives (VFDs) in North America, Central America, and the Caribbean.
To widen its North American drives market presence, Cutler-Hammer has sold Vacon's CX family of VFDs under its SV9000 brand since July 1998 (see CE , March 2000, p. 78; and Oct. 1999, p. 95).
The joint venture and new company- Vacon Americas -will build on the success of SV9000 by establishing greater North American presence, including local manufacturing.
Richard Gabel, manager of strategic development for Cutler-Hammer Power and Control Systems, will head Vacon Americas. A 'highly automated' production facility located near Milwaukee, Wis. is in planning, with operations to start in 2001.
Galil Motion Control Inc. has relocated to a 30,000-ft2facility in Rocklin, Calif., just east of Sacramento, effective Aug. 22, 2000. The new building will house Galil's headquarters, R&D, and product-support activities. Jacob Tal, president of Galil, cited quality of life and better business climate as key factors of the move.
In related product news, Galil's latest product announcement is a new series of motion controllers for Ethernet distributed control networks. E-Series controllers focus on solving problems associated with running systems of several servo motors. Wiring runs are minimized by the ability to locate the controller adjacent to motors or I/O points. Also, each controller can serve as a master unit ('virtual central controller') to simplify programming and communications. DMC-3425, a two-axis controller, is the first of the E-Series and sells for $695 in single quantity.
Animatics Corp. (Santa Clara, Calif.) has added multiaxis contouring capability to its SmartMotor product line. Now, two or more of these integrated packages-servo motor, controller, amplifier, encoder, and PLC-can do coordinated motion profiles ranging from linear/circular interpolation to multiaxis splines. PC-resident drivers provide the contouring feature.
Wanted: Users' views on integrated 'motor and drive packages'
Control Engineering 's December issue will feature an article about electric motors and drives integrated into one package. The focus will be on units with open-loop control-that is, mainly ac induction motors and inverter drive combinations (possibly brush dc units, as well). The separate category of servo motors/drives and closed-loop packages will be covered later in 2001.
I need your input on this special motor/drive technology. What is your experience or interest in applying this emerging product class? Users-and prospective users-of integrated motor/drive products (no suppliers) please send me your experiences, views, concerns, or estimates about this technology's potential. E-mail: firstname.lastname@example.org .
Seminars, exhibitions, training
'Working With Servos,' a seminar, presented by Bull's Eye Marketing Inc., Industrial Controls Consulting Div. (ICC, Fond du Lac, Wis.), starts another season with a session in the Detroit area, October 25-27, 2000. The three-day seminar-to be held at Radisson Suites (Farmington Hills, Mich.)-is intended mainly primarily for engineers seeking a basic understanding of servo system fundamentals and problems associated with applications.
Seminar presenters are Thomas B. Bullock, ICC president; George W. Younkin, ICC staff consultant; and Daniel B. Jones, president of Incremotion Associates (Thousand Oaks, Calif.), -all seasoned veterans in the field. Another presentation is scheduled for
April 4- 6, 2001
PowerSystems World 2000 Conference and Exhibit comes to Boston's Bayside Expo & Conference Center (Oct. 1-5, 2000), combining two shows, each with exhibits, technical papers, and tutorials: Power Quality 2000 brings solutions for ensuring power system reliability from the point of generation to the load. Technical presentations will include UPS solutions, distributed generation, surge suppression, motors and drives, transmission/distribution, and harmonics. .
PCIM 2000 coverage spans the range from high-frequency magnetics to intelligent power systems. This portion of the show is sponsored by PCIM Power Electronic Systems magazine. (PCIM was previously known as Power Conversion & Intelligent Motion magazine.)
Think & Do Software (Ann Arbor, Mich.) has introduced what it calls an Advanced E-Control Education and Training Course to give users of its software deeper knowledge to fully apply the features. A sampling of topics in the two-day course includes flowchart execution/scan architecture, tagname management, I/O diagnostics, and productivity analysis. For motion control practitioners, an additional day of training is available with such dedicated topics as serial motion controllers, homing, jogging, and basic moves. Class schedule is Sept. 12-13, Oct. 3-4, Nov. 7-8, and Dec. 5-6.
Information/guidance for the asking
Galco Industrial Electronics ' (Madison Heights, Mich.) new catalog should be of interest to various users, with drives, motors, power semiconductors (SCRs, power modules, etc.), encoders, relays, motor starters, and other control products well represented among more than 23,000 part numbers from 170-plus manufacturers. The 960-page catalog is available free for same day shipping. Tel: 800/521-1615.
It's called a 'brochure' by Baldor Electric Co. ; however, this new publication on Linear Motion Products has 242-pages. It covers three types of linear motors (brushless, stepper, ac induction) and their controls, linear positioning stages, Baldor's Mint motion control programming language, and software. Besides products, the brochure includes FAQs about linear motion technology, lists a glossary of pertinent terms, and provides prospective users information on linear motor requirements and motor sizing. Call 800/828-4929 for a free copy.
Control Engineering in September
Software for motion control shines in the current issue. 'Soft Motion'-or motion control functions executed in software, all on the CPU of an industrial PC-is put into perspective in an article by George Kaufman, president and ceo of Automation Intelligence (Duluth, Ga.). My follow-up online article (www.controleng.com) looks at further aspects of soft motion and the nontraditional 'paths' taken by this technology. The article also covers several other suppliers of soft motion technology and products, among them Beckhoff Automation (Minneapolis, Minn.).
How ac motors and drives have enabled a new cement plant process is covered in an Application Update. The news section contains an update on medium-voltage ac drive developments-especially units with larger power output that target tough steel rolling mill main-drive applications. Also in news, see a brief item on how the European motors and drives market fared in 1999.
New to North America, a 5th-generation dc drive from Siemens is featured in the products section. The all-digital drive ranges across 7.5-1,000 hp at 500 V dc. Other new products related to drives and motors worth scanning are: an integrated drive module for brushless and induction motors that adds velocity-servo mode of operation; and a solid-sate overload relay, offering remote programming for motor diagnostics. In 'Back to Basics,' see the two basic choices available to motion system developers for selecting a motion control amplifier.
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