ISSN 1345-3041

Elevators & Escalators Edition

VOL. 99/SEP. 2002

Vol. 99/September 2002 Mitsubishi Electric ADVANCE

A Quarterly Survey of New Products, Systems, and Technology

TECHNICAL REPORTSOverview ............................................................................................ 1by Yukio Kusuoka

The “ELENESSA” Machine Room-Less Elevator forOverseas Markets ............................................................................. 2by Hideaki Kodera and Takehiko Kubota

New Traction Machine for Machine Room-Less Elevators .............. 5by Kenji Inoue and Nobuaki Miyake

“Universal Design” in ELENESSA (Machine Room-Less)Elevators ............................................................................................ 9by Kazuko Matsuda and Masayuki Miyawaki

The New ΣΣΣΣΣAI-2200 Elevator Group-Control System ...................... 12by Masaaki Amano and Toshio Masuda

The Overseas Version of the MIC & RemoteMaintenance System ....................................................................... 16by Yasuhiko Tanabe

R&D PROGRESS REPORTThe World’s Fastest Elevators ......................................................... 19by Satoru Kato and Jun-ichi Higaki

TECHNICAL HIGHLIGHTSEscalators with High-Speed Inclined Sections ............................... 22by Manabu Ogura and Yasumasa Haruta

Diagnostic & Support Equipment for the Insulation ofTraction-Machine Motors ................................................................. 23by Teruo Konno and Naoya Yamada

NEW TECHNOLOGIESMELART-II; New Full-Color Paint Finish .......................................... 27

New Home Elevators ....................................................................... 27

CONTENTS

Mitsubishi Electric Advance is published online quarterly (in March, June, September,and December) by Mitsubishi ElectricCorporation.Copyright © 2002 by Mitsubishi ElectricCorporation; all rights reserved.Printed in Japan.

Cover StoryThis cover shows: (1) The car for our newmachine room-less elevator ELENESSAmodel together with the traction machine ituses (the slimmest in the industry). Thiselevator does away with the machine roomand thus allows for increased freedom inarchitectural layouts. (2) MELART-II doorswith full-color painted finish, allowing forhighly detailed depiction of any pattern youmay desire. (3) The hall operating panel forthe new ΣAI-2200 group control systemthat assigns cars in response to car calls.

Kiyoshi Ide

Futoshi TakahashiKoji KuwaharaKeizo HamaKatsuto NakajimaMasao HatayaHiroshi MuramatsuYoshimasa IshinoFuminobu HidaniYukio KurohataHiroshi YamakiKiyohide TsutsumiOsamu MatsumotoHiromasa Nakagawa

Hiroshi Muramatsu

Keizo HamaCorporate Total Productivity Management& Environmental ProgramsMitsubishi Electric Corporation2-2-3 MarunouchiChiyoda-ku, Tokyo 100-8310, JapanFax 03-3218-2465

Osamu KanamoriManufacturing Planning DepartmentInazawa WorksMitsubishi Electric Corporation1 HishimachiInazawa-shi, Aichi 492-8682, JapanFax 0587-24-5760

Editor-in-Chief

Editorial Advisors

Elevators & Escalators Edition

Vol. 99 Feature Articles Editor

Editorial Inquiries

Product Inquiries

· 1September 2002

TECHNICAL REPORTS

*Yukio Kusuoka is General Manager of Overseas Marketing Division.

OverviewNew Elevators and Escalators

by Yukio Kusuoka*

Here in Japan, there are very vocal concerns regarding the hollowing out ofindustry or the loss of technological precedence. In the world of elevators, it is afact that we have allowed the Europeans to get ahead of us in machine room-lesselevators and that the Chinese and Korean manufacturers whose selling point istheir cheap prices are catching up on us. But, stop for just a moment. Has Japan’sability to produce really become so enfeebled?

Japanese merchandise, which right after the war was a synonym for cheap, poorquality goods, is now recognized for its top quality globally. Japanese manufacturershave found their driving force in an unswerving focus on cultivating manufacturingtechnologies and skills with the aim of producing high quality products; Japan’ssuperiority in this regard remains unshaken. Notably, for elevators, which serve asa vertical transit system, reliability and safety are of critical importance.

This concept of quality as number one is a constant throughout Mitsubishi el-evators’ history, and our products have gained an excellent reputation from custom-ers in the major markets. With reliability and safety as the basis, we are also givingconsideration to comfort, efficiency, as well as people-friendly designs and protec-tion for our earth’s environment. Always producing products that anticipate thedemands of the times — this is the basic concept of Mitsubishi elevators.

We at Mitsubishi Electric can introduce with all confidence our machine room-less elevator ELENESSA, equipped with slim-line gearless traction machines (de-veloped in-house). No matter what aspect you consider, be it layout, ride comfort orquietness, these are unparalleled landmark products. Technologies for thecorporation’s slim-line gearless traction machines will continue to evolve, and soon,based on these technologies, we will be able to ship product lines that cover alltypes of elevators from low-speed to ultra-high-speed models.

In addition to these products, through the pages of Advance we are introducingother new products and technologies that will lead the 21st century. Combiningan accurate grasp of market needs with cutting-edge technologies generated by ourongoing research and development activities, and so continuing to produce tech-nologies and products that can become global standards — this, I submit, is MELCO’smission as a leading manufacturer.

Mitsubishi Electric’s elevators and escalators will always continue to evolve, inorder to supply products of the highest quality, products that customers can usewith peace of mind and no regrets over many, many years.

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Mitsubishi Electric ADVANCE2 ·

*Hideaki Kodera and Takehiko Kubota are with Inazawa Works

by Hideaki Kodera and Takehiko Kubota*

The “ELENESSA” Machine Room-LessElevator for Overseas Markets

Mitsubishi Electric Corporation has developed anew machine room-less elevator for overseasmarkets, the “ ELENESSA,” sales of which beganin April 2001. ELENESSA elevators require lessspace for installation than any other elevatormodel in the industry and adopt universal de-sign practice for greater convenience. This prod-uct conforms to EN standards, which pay fullconsideration to maintenance and to safety inthe event of emergencies. This article discussesthe concepts on which development of ELENESSAwas based and describes the features and new tech-nologies incorporated in this elevator series.

Product ConceptsIn developing ELENESSA, Mitsubishi Electricengineers aimed at an elevator that would be usednot only in Europe but also in Asia, the MiddleEast, and other world markets. Productdevelopment kept to the following three principles.

GREATER FREEDOM OF ARCHITECTURAL DE-SIGN. Engineers strove to reduce the space re-quired for elevator installation, aiming at aneasy-to-install elevator that would occupy thesmallest amount of space in the industry, in or-der to make effective use of building space andto cut construction costs.

UNIVERSAL DESIGN. The concepts of universaldesign introduced in 1997 were taken further,with operation improved and panel indicatorsmade easier to understand, so that the elevatorcould be readily operated by the elderly and bythose with disabilities. The aim was to createan elevator that everyone would find easy to use.

EVOLUTION OF MITSUBISHI QUALITY. Anothergoal was to ensure the quality, performance andreliability that have traditionally distinguishedthe corporation’s elevators, while adding furtherenhancements to an even safer and more reli-able elevator product.

Product Features and New Technologies

SYSTEM CONFIGURATION. The traction machine,control panel and all other equipment are installed

within the elevator shaft, and the principal ma-chinery has been made more compact for greaterspace savings. Fig. 1 shows the ELENESSA sys-tem configuration. The traction machine is in-stalled at the upper end of the guiderails forcounterweights, installed vertically in the eleva-tor shaft; an underslung 2:1 roping system wasadopted in which a counterweight is hung on asuspension rope. By employing a self-supportingdesign in which the traction machine and bothends of the suspension rope are supported by theupper part of the guiderail, the vertical-directionloads of the elevator are supported by guiderails,thereby alleviating the load placed on the build-ing. The overall system configuration conformsto EN81-1 and to EN81-1:2000/prA2:2002.

Slim gearless traction machinewith PM (permanent magnet) motor

Slim control panel

Hall inspection panel

Suspension ropes

Direct drive smart door system

Counterweight

Slim car operating panel

Car guide rails

Counterweight guide rails

Fig. 1 Construction of ELENESSA

SLIM PM GEARLESS TRACTION MACHINE. Asthe traction machine, a slim gearless tractionmachine incorporating a permanent magnet(PM) synchronous motor was adopted. Fig. 2 is

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· 3September 2002

an external view of the slim PM gearless trac-tion machine (3.7 kW). This equipment drawson the corporation’s own closely wound statorsand the development of compact double brakesfor incorporation in traction machines, helpingto reduce the equipment radial thickness to 187mm (one fifth or less than that of previous mod-els) at a rating of 3.7 kW. Motor-torque ripplewas reduced through magnetic pole analysistechniques, for a smoother, more pleasant el-evator ride.

SLIM CONTROL PANEL. Because the controlpanel needed to be installed in the limited spacebetween the car and the elevator shaft, a slimcontrol panel only 98mm thick and 340mm widewas newly developed. Fig. 3 is an external viewof this panel. The control and driving circuitryassembled within the control panel consists oftwo types of highly integrated subunits, an inte-grated power unit (IPU) and a control process-ing unit. The IPU integrates a DC/DC converterspecifically for elevator control with an inverterfor elevator drive, based on an intelligent powermodule (IPM), over a single heat sink, to obtaina highly integrated power supply and driving unitwith a thin shape. The control processing unitis equipped with a large-scale system LSI for el-evator equipment for more functionality and ahigher level of integration.

DIRECT-DRIVE SMART DOOR DEVICE. A slim PMsynchronous motor was newly developed for thedoor-drive motor, adopting a direct-drive designwithout a decelerator; the door-drive motor wasincorporated in the door device (Fig. 4). In this

Fig. 2 Slim gearless traction machine with PMmotor (3.7kW).

IPU(Integratedpower unit)

Controlprocessingunit

Fig. 3 Slim control panel

Door driving unit

Direct drivePM (permanent magnet)door motor

Fig. 4 Direct drive smart door system

way, the space occupied is reduced to just 60%of the volume of conventional door devices, fora dramatic improvement in layout freedom andsubstantial space savings. Also, the door-driveunit has an auto-tuning function that monitorsthe weight and condition of the doors on eachfloor and optimizes door opening/closing. As aresult, door opening/closing performance issmoother and more stable.

COMPACT GOVERNOR. Installed at the top of theelevator shaft, this compact governor is reducedto just 60% of the size of conventional equip-ment. A remote-operation mechanism is pro-vided so that tests to confirm operation duringinspections, and operation in the event of an

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emergency, can be performed from the hall with-out accessing the elevator shaft.

SLIM CAR-OPERATING PANEL. The newly devel-oped car-operating panel is slim (only 25mmdeep) and can be housed within a panel in a carside wall. As a result, the dimensions of the el-evator shaft can be further reduced.

UNIVERSAL DESIGN. The universal designadopted for existing GPQ models has been fur-ther extended and a design developed with caretaken to ensure ease of use by everyone. Fig. 5shows an example of this universal design. Thecar-operating panel is positioned on a side wallof the car so that it is immediately visible onentering the elevator. Button positions andheights are also set such that even children andpersons in wheelchairs can operate the eleva-tor. The indicator characters in the car are en-larged to 1.6 times their usual size, making themeasy to read. Also, the characters in the buttonsof the car operating panel and in hall call but-tons are embossed, so that they can be touchedand understood by persons with impaired eye-sight. Finally, by enlarging the open-door buttonwithin the car compared with other buttons (by1.6 times), the chances that the wrong buttonwill be pressed are reduced.

and adequate space for maintenance is provided.To further ensure safety, a car-locking device isprovided to mechanically prevent any unexpectedmovement of the car during maintenance.

HALL-INSPECTION PANEL. A hall-inspectionpanel is built into the hall call button panel onthe top floor, so that the elevator can be oper-ated without entering the elevator shaft duringmaintenance inspections and in times of emer-gency. In addition to indicators showing the el-evator stage, the hall-inspection panel includesan operating switch for use in maintenance andinspections, an emergency rescue operationswitch, an emergency stopping device, and otherdevices and functions to ensure the operation ofsafety mechanisms. The hall-inspection panelis installed within a box behind the hall call but-ton panel on the top floor so as not to compro-mise the aesthetics of the hall (see Fig. 6).

Large indicator

Tactile buttons

Car operating panelin the car side wall

Large open buttons

Fig. 5 Universal design for car

SAFE MAINTENANCE ON THE CAR ROOF. Main-tenance of the traction machine, control paneland other equipment installed in the elevatorshaft is performed on the roof of the car. To en-sure greater safety for these maintenance opera-tions on the car roof, it has a flat, non-skid surface

Hall call button Hall inspection panel

Fig. 6 Hall inspection panel behind hall callbutton

The new features and new technologies of theELENESSA elevator, sales of which commencedin April 2001, are a landmark in MitsubishiElectric’s ongoing commitment to make furtheradvances in speed, capacity, and other areas. Wewill be working to develop technologies for thefurther evolution of the corporation’s elevatorproducts.

Reference[1]Yoshikatsu Hayashi, Shigeki Yamakawa, and Takashi Yumura:

“The ELEPAQ-i Mitsubishi Machine Room-Less Elevator”, Mitsu-bishi Electric Technical Journal, 75, No. 12, 766-771 (2001).

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· 5September 2002

*Kenji Inoue is with Inazawa Works and Nobuaki Miyake is with the Manufacturing Engineering Center.

by Kenji Inoue and Nobuaki Miyake*

New Traction Machine for MachineRoom-Less Elevators

Mitsubishi Electric Corporation has developeda new traction machine for machine room-lesselevators. The world-leading slim form factor pro-vides for great convenience in layout design. Inaddition, the slim traction machine also runssmoothly, ensuring a comfortable ride, and canbe manufactured with high productivity. Thisarticle introduces the structure of this slim trac-tion machine and the motor technology thatmade it possible.

Features of the Slim Traction MachineAs well as possessing the basic functions andperformance required of drive equipment for el-evators, the new traction machine for machine-room-less elevators had to be compact and quiet.With the GPQ series, which the corporation firstmarketed in 1999, we eliminated the need for amachine room by using permanent magnet (PM)synchronous motors to develop a cylindrical formof gearless traction machine. Now, we havedeveloped the new slim traction machine, de-signed to be flat and thin, to improve the ma-chine layout in the hoistway. Fig. 1 shows thenew slim traction machine, released in October2001, that was developed for ELENESSA eleva-tors. Its features are listed below.

Fig. 1 External view of slim traction machine.

First, the size has been reduced to a world-leading slim form factor. In addition to imple-menting the corporation’s proprietary joint-lapped core, the rotor, sheaves, brakes, and en-coder were all included in the unit. In the 3.7kWmodel we achieved a unit that was 187mm inaxial dimension, less than 20% the size of theprevious product.

Second, the ride is comfortable. Using thecorporation’s expertise in magnetic field analy-sis, we reduced torque ripple. The result is aride that lives up the long-standing reputationof Mitsubishi elevators for quiet and smooth-riding comfort.

Third, productivity is excellent. As well asimplementing automated winding of the motorthrough the use of concentrated winding tech-niques, the assembly procedures were also sim-plified by integrating the rotor, sheaves andbrakes into a single unit, while at the same timeadopting other methods of raising productivity.

Traction Machine StructureFig. 2 compares the structure of the previoustraction machine and the recently developed slimtraction machine. As long as the sheaves, mo-tor, brake and encoder were set in series alongthe same axis, the space required to accommo-date this configuration limited the possible re-duction in length. In the slim traction machine,the motor’s rotor has been given a hollow cylin-drical form and this allows the inner surface tobe used for an internal expanding double brake.Moreover, the encoder has been installed withinthe space inside the brake mechanism. Then, byintegrating the rotor and sheaves within the unititself, and by dispensing with coupling parts, thedimensions of the equipment were reduced andreliability was raised. Overall, denser mountingof the internal components of the traction ma-chine enabled minimization of the external di-mensions.

Furthermore, the ultimate form and configu-ration of the main unit were decided after struc-tural analysis to ensure adequate strength andrigidity under loads encountered in normal run-ning, at emergency stops, during manufacture,and under various other conditions.

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Ultimately, along with reduction of the sizeof the motor, brakes, and other elements, struc-tural analysis enabled us to optimize the formof the equipment so that the 3.7kW model ofthe slim traction machine weighed only about300kg, some 33% less than the equivalent pre-vious model.

Motor Electromagnetic Engineering DesignFor machine room-less elevators Mitsubishi Elec-tric implemented PM synchronous motor tech-nology that combined compact form and hightorque at low speed. During the development ofthe slim motor, as in the past, we adopted high-performance rare-earth magnets. There werefour other additional main design features: con-centrated winding methods; high density ofampère-conductor; larger diameter; and multi-pole configuration.

Compared with distributed winding, concen-trated winding enables reduced motor size be-cause coil ends are smaller. Besides this, we

Fig. 2 Comparative structure of tractionmachines.

Above : Previous type of traction machineLeft : Slim traction machine

Sheaves Bearing Motor Bearing Brake Encoder

Fig. 3 Effect of multipole design.

Stator

Rotor

Large number of poles Small number of poles

Core back

Iron core

Core back

Permanentmagnet

Coil

Shaft side view

were able to apply proprietary joint-lapped coretechnology to achieve both high density wind-ing (and therefore higher ampère-conductor den-sity), and improved productivity throughautomated winding.

Multi-pole design is a common approach todown-sizing motors. As shown in Fig. 3, in thismotor it enabled shortening of the coil ends andreduction of the radial dimension of the motor.In multi-pole designs, the magnetic flux betweenthe poles can be weaker at smaller pole pitches.This allows the core back of the iron core to bethinned and also makes it possible to reduce theradial thickness of the stator and rotor. More-over, because a big space within the rotor be-came available, in this case it became possibleto mount the brake there, thus enabling a com-pact design for the entire traction machine.

Motor-Manufacturing TechnologyIn the development of any high-performancemotor it is important to review the basic struc-ture of the motor from the point of view of manu-facturing productivity. Once the fundamentaldesign is settled, it is no longer possible to makeextensive improvements in working proceduresand assembly, and further dramatic improve-ments in the overall motor characteristics arenot to be expected.

As Fig. 4 shows, at Mitsubishi Electric we havedeveloped a “ joint-lapped core” technology thatfeatures flexible joints. The joint-lapped core is ableto open and be bent back at the joint for winding

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· 7September 2002

easily. This design has been applied to various ofthe corporation’s motors. For each product, the coilspace factor has been greatly improved. As wellas achieving lighter, more compact motors withhigher efficiency, we are moving towards completeautomation of winding.

Built up in successive layers with high preci-sion, the joint-lapped cores are straightened in po-sition after extraction from high-speed presses. Theforms in the presses work on flat rolled magneticsteel that is fed in strips. By synchronizing thefeed switching from multiple dies and punch blades,the structure is built up and an arrangement offlexible articulating joints is produced.

As shown in Fig. 5, while winding, the joint-lapped core is bent back at the joint. The coil-winding nozzle can be moved in a circular locusbecause free space is available around the teeth.This means that no distortion arises by addingunnecessarily to coiling wire. It is possible toachieve perfect coil alignment with thick wirecoils. Moreover, rather than using a single ironcore with large diameter, the joint-lapped coreis radially divided. This increases the yield whenthe cores are stamped and improves transportefficiency during stator production.

Torque Ripple ReductionTo ensure a comfortable elevator ride, one of thetechnologies that Mitsubishi Electric has been

successfully adopting is motor-torque ripple re-duction. In the recently developed slim tractionmachine, there was initially a tendency towardincreased torque ripple because of the markedsize reduction and the use of a concentratedwinding method. Torque ripple was greatly re-duced, however, by considering magnetic satu-ration and potential production errors at thedesign stage. The resulting slim traction ma-chine provides the same smooth riding comfortthat has always been the mark of Mitsubishielevators.

The slim motor design features high densityof ampère-conductor. Consequently, torqueripple tends to increase because stator teeth areeasily subject to magnetic saturation during highcurrent loads. After using magnetic field analy-sis to investigate different forms and dimensionsof teeth, we abandoned the previous semi-closed

A type

B type

Teeth 1

Teeth 2

Teeth 3

Magnified view of X- X cross section

For layer fixing

For layer fixing For layer fixingFor linking For linking

(Joint)

Teeth 1 Teeth 2Joint

Freely rotating

X

X

Fig. 4. Structure of articulating joint-lapped core.

Coil-winding nozzle Teeth

Joints

Bent back iron core

Fig. 5. Iron core at time of winding.

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Rel

ativ

e to

rque

rip

ple

(mag

netic

fiel

d an

alys

is r

esul

ts) *) Relative to base value of 100 set for previous model during normal running

During normal running

During overload Teeth configuration

Semi-closed slot

Semi-open slot

Previous design (semi-closed slot) Improved design (semi-open slot)

150

100

50

Fig. 6 Comparative torque ripple results.

slot for a semi-open slot design. Consequently,magnetic flux leakage from the tips of the teethmitigated magnetic saturation. This change, asshown in Fig. 6, halved torque ripple during over-load and cut it by a third during normal run-ning. The overall result was to reduce torqueripple across a broad range of operation.

Errors that occur during manufacturing pro-cesses increase torque ripple and cause productvariations. We therefore analyzed the types ofmanufacturing error that can lead to torqueripple. To thoroughly clarify the relationshipbetween such working errors and torque ripple,we freely applied magnetic field analysis in vir-tual engineering. Reflected in both motor designand production management, the results of thisanalysis brought about the benefit of motors withlow torque ripple and consistent production.

As well as finding ways to extend the applica-tions for slim traction motors, we are commit-ted to further improving elevator productperformance and quality. We remain determinedto develop attractive products that have winningappeal.

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· 9September 2002

*Kazuko Matsuda is with Inazawa Works and Masayuki Miyawaki is with the Industrial Design Center.

by Kazuko Matsuda and Masayuki Miyawaki*

“Universal Design” in ELENESSA(Machine Room-Less) Elevators

Universal design implies the creation of prod-ucts that are easy for all to use irrespective ofage or disability. The concept of universal de-sign is central to Mitsubishi Electric’s machineroom-less ELENESSA elevators; newly added fea-tures include side-panel mounted car-operatingpanels and raised character buttons.

Universal Design for ElevatorsTo summarize, universal design is design thateveryone finds equally easy to use. “ Everyone”here specifically includes people with disabili-ties and the elderly along with regular users.With deepening understanding of aging societ-ies and their physically or otherwise challengedmembers, universal design is becoming moreimportant in a number of fields.

Elevators perform the function of vertical trans-port for their users, and they operate under verysimple controls, but in the limited space of anelevator car it is extremely difficult, and thereforeimportant, to create interfaces that are equallyeasy to use for each of a number of unspecifiedusers.

On a global scale, as many efforts are beingmade to improve the mobility of the disabled,there are more countries that have legislationcovering disabled persons and elevators; incor-porating universal design in products is there-fore becoming essential.

Also, we should work to improve the elevatorexperience, relieving the unease users may feelwhile they are cooped up in the elevator car,and the impatience they will feel while waitingat the landing.

Mitsubishi Electric’s new machine-roomlessELENESSA elevator is based on universal design,and the article describes its use in this product.

Main Universal Design Features in theOperation and Display Devices

SIDE-PANEL MOUNTED CAR-OPERATING PANELS.The car-operating panel is depicted in Fig. 1. Bymoving car-operating panels from beside thedoors (the front return panels, where they havepreviously been mounted) to the side panels, weachieve the following benefits:

Fig. 1 Car design

It is easier to find the car-operating panelswhen entering the elevator (they catch your eyeas the doors open).

Users in wheelchairs can operate the car with-out having to wheel themselves around (or reachback over their shoulder) within the car.Even for non-wheelchair users, not needing toturn around to get the car moving means greaterease of use.

Building Regulation 1999 M2 (of the UnitedKingdom) stipulated that the appropriate mount-ing location for a car-operating panel is the sidepanel, at least 400mm away from the front wall.The reason for this appears to be to make it easyfor users in wheelchairs to use the buttons afterentering the car. For this product, we paid strictattention to ease of use, and decided to mountcar-operating panels in locations which wouldsatisfy the condition described above.

MOUNTING HEIGHT FOR BUTTONS. Legal codessuch as the Building Regulations, ApprovedDocument M2 of 1999 (of the United Kingdom)and Code on Barrier-Free Accessibility in Build-ings 1995 (of Singapore) have stipulations regard-ing the mounting height for car-operating

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buttons, based on considerations of the issue ofoperability by the disabled. For this product,based on these code stipulations, we have lo-cated car-operating buttons between 900 and1200mm above the car floor. Also, by puttingthe Open, Close and Alarm buttons below theFloor buttons, even those who cannot reach veryhigh can readily operate them. Thus, even if chil-dren or others whose hands cannot reach veryhigh enter the car by mistake, our design al-lows them to avoid entrapment by using theOpen button. Also, if an entrapment were to takeplace, parties outside the car can be notifiedthrough use of the Alarm button.

SYMBOLS ON OPERATING BUTTONS. A generalview of the operating panel is given in Fig. 2.Embossing the numbers and symbols found onoperating buttons enables them to be read bytouch. This aids users who are visually handi-capped but do not read Braille.

Numbers and symbols are raised 1mm abovethe button surface; we determined the preciseembossing patterns to use based on evaluative

(a) Picture of whole panel

(b) Operating buttons

Fig. 2 Car-operating panel

tests performed with 20 men and women withimpaired vision (including individuals with weakeyesight and the totally blind, both those bornwith impaired sight and those whose vision waslater impaired). In these evaluative tests, weprepared various different samples with manyembossing patterns, and had the subjects evalu-ate the relative ease of understanding buttonsby touch (Fig. 3 and 4). As a result, it becameclear that readily understood designs were thosewhere the embossed edge was thin, and the pat-terns were clearly raised above the button sur-faces.

Fig. 3 A scene from testing

0 .8 mm 0 .8 mm

R0 .5 R0 .4 R0 .2

1 .5 mm 1 .5 mm 1 .5 mm

Proposal AVertical riseR0.5

Proposal BCharacter width at point 0.8R0.4

Proposal CCharacter width at point 0.8R0.2

Fig. 4 Cross section of sample embossedcharacters

In evaluating embossing patterns, it becameclear that ease in understanding by means oftouch is influenced by choice of character fonts,and so we adopted a character font more easily

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· 11September 2002

distinguished than our previous choice (Fig. 5).For instance, when compared to the previousfont, the difference between “ 6” and “ 9” is muchclearer in the new font, and is readily distin-guished even by those with weak sight.

car, improving the car’s anti-crime profile andproviding a greater sense of freedom whilewithin.CAR MIRRORS. We have added an optional full-height mirror running from floor to ceiling. Tokeep this from being a hindrance to car passen-gers, the face of the mirror is flush with the carwall, eliminating any protrusion into the car.

HANDRAILS. We expanded the handrails to a di-ameter of 38mm (32.5mm in previous models),based on anatomical research data, and made iteasier to grip. Also, we will put the plaquetteportion at an angle as shown in Fig. 6, improvingthe join of the corners to the wall so that clothes,etc., will not get caught on handrail ends.

Fig. 6 Handrails

New font (Remodeled based on Gill Sans Medium)

Previous font (Helvetica)

Fig. 5 New numeral designs for buttons

Also, car buttons for the main floor have beenmade green, and raised about 5mm more thanother buttons. This is done in order to make iteasier to detect evacuation floors in case of di-sasters; these main-floor buttons stand out abovethe other buttons, so even the visually impairedcan readily distinguish evacuation floors.

ENLARGING THE OPEN BUTTONS. Since it is hardto distinguish immediately between the Openand Close buttons, we have changed the size ofthe Open button as shown in Fig. 2, making iteasier to recognize it instantly. We chose theOpen button to make it easier to use, since itmay need to be used instantly.

CAR INDICATORS. We enlarged the charactersize in car indicators (about three times the sur-face area of previous models), thus improvingvisibility.

Major Universal Design Features for the Carand Landings

DOORS WITH LARGE WINDOWS. Doors withlarge windows have been added as an option.Installing windows in the door has the effect ofalleviating the sense of confinement within the

We investigated laws throughout the world writ-ten considering the physically handicapped, andhave been able to create a product that satisfiesboth ease-of-use demands and legal require-ments. However, when considered in terms ofthe lofty ideal of universal design— easy use byanyone— we would claim no more than that thisproduct is a step in the right direction. We arecommitted to achieve further and greater im-provements in this direction.

References1. Office of the Deputy Prime Minister, Government of the United

Kingdom, Building Regulations Approved Document M, Section M2(1999).

2. Ministry of National Development, Building Construction Authority,Building Control (Singapore) Code on Barrier-Free Accessibility inBuilding 1995.

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Mitsubishi Electric ADVANCE12 ·

*Masaaki Amano and Toshio Masuda are with Inazawa Works.

by Masaaki Amano and Toshio Masuda*

The New ΣΣΣΣΣAI-2200 ElevatorGroup-Control System

The ΣAI-2200 system incorporates new func-tions such as a dynamic rule-set optimizer thatselects the appropriate rule according to changesin traffic conditions, a destination oriented pre-diction sub-system that controls car allocationaccording to the destination floor, etc., by adopt-ing new technologies such as high performanceRISC processors, a real-time OS and a networkdedicated to group control using Ethernet.[1]

BackgroundWith advances in the application of intelligenceto today’s increasingly complex buildings, wehave entered an age where high performanceand diverse functions are being sought in thegroup-control system for elevators. In conven-tional group-control systems, a fixed car allo-cation rule set was used for each traffic pattern(e.g., if it was the morning rush hour, the gen-eral purpose rule set for the morning rush hourwas used). However, traffic is different for eachbuilding and car allocation applied with the gen-eral-purpose rule set may not always be opti-mal. Therefore, a new system called thedynamic rule-set optimizer was developed forthe ΣAI-2200. This system performs a simula-tion on a number of morning rush-hour rulesets prepared in advance with a real timesimulator loaded in the ΣAI-2200 and selectsthe optimum rule set.

This system was configured to enable thegroup-control system to be provided with a simu-lator for verifying the effect of group control asconventionally performed using personal com-puters. This simulation requires a high arith-metic performance from the main computer thatperforms the group-control arithmetic. The per-formance of microcomputers has improved no-ticeably in recent years and generic RISCmicroprocessors capable of high-speed arithmeticoperations are available. A RISC processor is em-ployed as the main computer for group controlin ΣAI-2200 to implement the real-time simula-tion function mentioned above.

Also, with enhanced group-control perfor-mance and the addition of new functions, thereis a need to strengthen communications be-tween the group control and the elevator con-

trol panel and between the group control andthe hall operating devices. Communication tech-nology has scored remarkable advances in re-cent years, demonstrating high communicationperformance and reliability. Application has nowbecome possible even for communication be-tween the devices of elevators requiring highcommunication performance and reliability.

System ConfigurationFig. 1 shows the system configuration. It fea-tures the group-control CPU card with improvedarithmetic performance and the communicationnetwork with enhanced and expandable com-munication capabilities.

CPU Board for Group ControlFig. 2 shows the appearance of a CPU board forgroup control. A CPU is provided for eachassigned function on the board and there arethree CPUs, namely, a RISC processor for per-forming the main arithmetic for group controlsuch as allocation, learning, etc., a CPU for com-munication control, and a CPU for general pur-pose I/O control. In order to obtain the higharithmetic performance particularly necessaryfor real-time simulation, a type with a floating-point co-processor was selected for the group-control arithmetic RISC. The clock runs at 200MHz. Also, a real-time OS with the µITRON3.0[2] specifications has been loaded in order toenhance the reliability of the system.

Due to the optimization of the bus betweenthe RISC and the peripheral devices, the highspeed clock at the core of RISC, and havingoptimized the S/W configuration so that theinstruction cash and data cash functioneffectively as described above, improvement inthe group control main arithmetic performanceof about ten times that of the conventional groupcontrol system was achieved.

Communication NetworkThe communication system comprises a groupcontrol– control panel communication network(or more briefly, “ group-control network” ) andan optional network that connects the new halldevices, etc.

TECHNICAL R EPORTS

· 13Septamber 2002

Fig. 3 shows the protocol of the group-controlnetwork. This group-control network usedEthernet for the physical layer of the networkin order to secure expandability and flexibilityfor the future and to create a network suited forthe recent intelligent building systems.

Group control device

Seven segment LED

Clock

Watchdogtimer

Flash memory

Group control arithmetic part 32 bit RISC

RAM

CPU card

General purpose I/O interface

Group control communication interface

16bitCPU

16bitCPU

- High performance RISC CPU- Real-time OS

- Expandability and flexibility- Application of Ethernet- Original protocol

32bit

64bit

Group control network

Option network

Warning panel

Group control communication interface

- Response and reliability- Application of field bus- Original protocolControl

device for each car

Destination floor indicator

Hall lantern appended with service elevator code indicator

Hall device

Hall operating panel

6

4

2

B

B

77

5

5

3

A

AA

Fig. 1 System configuration

Flashmemory

RAM

General purposeI/O control CPU

Communicationcontrol CPU

Group controlArithmetic RISC

Fig. 2 CPU board for group control

Classifications of the OSI reference model

1234567

Layer Name of layerApplication layerPresentation layerSession layer

Token control

Transport layerNetwork layerData link layerPhysical layer

Network specifications for each group

ApplicationData management

Failure managementBoarding/exiting control

10BASE-T

Fig. 3 Protocol construction of group-controlnetwork

Furthermore, to enhance the reliability of thecommunication system and to secure adequateresponse, a node-separating function has beenprovided for cases where a new connection orfailure in the network node is generated. Con-sequently, adequate network reliability has beensecured so that device additions or node failuresdo not influence the whole network.

Improved communication capabilities are es-sential in the destination-oriented prediction sys-tem discussed below. Therefore, response and

TECHNICAL R EPORTS

Mitsubishi Electric ADVANCE14 ·

reliability were secured by means of a data-colli-sion bypass protocol and an optional networkbased on a field bus of superior expandability fordevice additions. With this optional network, thecommunication capabilities improve and even therestriction on the number of floors installed witha hall operating panel is relaxed considerably.

New Functions

DYNAMIC RULE-SET OPTIMIZER. The dynamicrule-set optimizer is realized by combining threesub-modules, neural networks, a group-controlrule base, and a real-time simulator as shown inFig. 4.

The neural networks detect the traffic patternsduring the morning rush hour, regular hours,etc., as well as performing a more detailed esti-mate of the traffic data and outputting the esti-mated data. The group-control rule base is storedwith each set of rules peculiar to a specific traf-fic condition as a group-control rule set. Also, a

number of rule sets capable of optimization areselected as rule-set candidates according to thedetected traffic pattern. The real-time simula-tor performs its simulations when the rule-setcandidates and the estimated traffic data areinput, and then the waiting time and the ser-vice completion time are output for each ruleset. The optimum rule set is selected based onthis output. In group-control execution, controlssuch as call allocation, dispatching of cars, etc.are executed in accordance with the optimumrule set.

DESTINATION-ORIENTED PREDICTION SYSTEM.A hall operating panel that replaces theconventional UP/DOWN type hall buttons isinstalled at the hall on the lobby floor. Fig. 5shows the configuration of the device. In thishall operating panel, a service-elevator code in-dicator that shows the assigned service eleva-tor code was mounted near the destinationbuttons so that the passenger who pushes the

NN: Neural network

Group control rule base NN for detecting

traffic pattern

Traffic pattern

Rule set candidate

NN for estimating traffic

Estimated trafficdata

Rule set 1

Rule set 2

Real-time simulator

Rule set selection evaluation part

Optimumrule set

Group control execution part

Fig. 4 Dynamic rule-set optimizer

TECHNICAL R EPORTS

· 15Septamber 2002

2

4

6

8

10

12

1413

11

3

5

7

9

B

B

AA

A

11 13 14

Destination floor indicator

Hall lantern appended with service elevator code indicator

Hall operating panel

Allocated service elevator code indicator

Destination button

Fig. 5 Destination-oriented prediction system

destination button can know the code of theassigned service elevator immediately.

Operation is as follows. When it is the morn-ing rush-hour zone and up peak time is detectedby the neural network, dispatching of cars ac-cording to the respective destination floor (carallocation tuning) takes effect. During this time,the elevator transports the passenger to thedestination floor according to the following se-quence.

1. The optimum car is selected for each desti-nation call made at the hall and this is notifiedto the passenger with the hall lantern andthe service-elevator code indicator.

2. The maximum number of possible destinationcall registrations allocated to one car isdetermined according to the aforementioneddynamic rule-set optimizer and if destinationcalls in numbers exceeding this value are reg-istered, a newly predicted car is selected incompliance with the destination call.

3. When it has been detected that the passen-ger has boarded the predicted car, the desti-nation call allocated to the pertinent car isregistered automatically.

By applying the destination-oriented predictionsystem, the number of destination calls for eachcar per run can be reduced due to the effect ofcar allocation tuning, the transport efficiency isimproved, and the congestion at the lobby floorcan be minimized.

In the future, we intend to make further ad-vances in elevator group-control systems suchas interlocking with the building security sys-tem, etc., to further accommodate the applica-tion of intelligence in buildings.

References[1] Ethernet is a registered trademark of Xerox Corporation.[2] µITRON is Micro ITRON, ITRON is Industrial TRON, and TRON is

an abbreviation for The Real Time Operating System Nucleus.

TECHNICAL R EPORTS

Mitsubishi Electric ADVANCE16 ·

*Yasuhiko Tanabe is with Mitsubishi Electric Building Techno-Service Co., Ltd.

by Yasuhiko Tanabe*

The Overseas Version of the MIC &Remote Maintenance System

The overseas version of Mitsubishi informationcenter (MIC) and remote maintenance systemswill improve maintenance inspection techniquesand capabilities in responding to fault conditionsin Mitsubishi Electric Corporation’s elevatorsoverseas, and will also make it possible to handleremote maintenance, which is beginning to beimplemented in world markets.

At present, overseas MIC systems are beingimplemented by International Elevator & Equip-ment (Philippines), as well as companies suchas Ryoden (Malaysia), Worachak International(Thailand), Mitsubishi Electric Saudi (SaudiArabia) and P.T. Mitsubishi Jaya Elevator andEscalator (Indonesia). This is bringing significantperformance improvements.

We are also seeing the introduction of remotemaintenance systems, from Shanghai MitsubishiElevator Co. (China), through Ryoden Lift Ser-vices Limited (Hong Kong) and ETA-MELCOElevator (U.A.E) to China Ryoden Co. (Taiwan).Shanghai Mitsubishi Elevator Co., Ltd. plans toinstall 500 remote maintenance systems in thismarket during the current fiscal year.

The corporation’s plans involve constructinga world-wide network that links the domesticMIC system with overseas MIC systems, as wefurther envision the possibility of supportingfrom Japan the collection and analysis of diag-nostic elevator data by means of remotemaintenance in conjunction with fault data andcustomer information.

System Configuration:The overseas version of the MIC/remotemaintenance system allows the unifiedsupervision of all circumstances related to faultrepairs through telephone contact with ourclients and through receipt of signals frommonitored elevators. We developed this overseasversion by identifying the minimum essentialfunctionality within our Japanese system, seeFig. 1.

This system is made up of a client/server typepersonal-computer based MIC system (with Win-dows NT operating system and an ORACLE da-tabase) and a remote maintenance system,

where software for remote maintenance isloaded into the elevator’s operating panel.

As subsystems under both of these systems,we will set up communications control devices(devices with automatic incoming/outgoingphone-line control functions), establishing datatransmissions between the call center andelevators over public phone lines.

Functions and their Effects—the MIC system.

RECEIPT OF MALFUNCTION REPORTS. Tele-phone contacts with customers and the receiptof elevator signals are all drawn together anddealt with at call center.

Since this makes it possible to conduct detailedbreakdown analyses using accumulated fielddata, this can lead to improvements in the qual-ity of maintenance work and strengthen call-back service (CBS) management capabilities.(CBS is used to identify a breakdown-responsesystem where maintenance personnel are sentout immediately after receipt of a dispatchrequest from customers, or once we receive a“ dispatch signal” transmitted under the main-tenance operations protocol of a remote moni-toring device.)

Furthermore, it is possible to record contractinformation that goes beyond customer informa-tion and the points of concern in dealing withcustomer issues. This other information can thenbe utilized in what we may translate as a regis-try of simple maintenance contracts and for vari-ous types of administrative data.

SUPERVISING DISPATCHES FOR FAULTS. Elevatorby elevator, we are managing the whole se-quence of events from the occurrence of the fault(whether learned about by transmissions from aremote monitoring device or communicated overthe telephone) to the order for dispatch of per-sonnel, the actual dispatch, arrival of the main-tenance team and completion of repairs.

Based on this, it is possible to confirm and fol-low through the status when any aspect of faultrepair is omitted or delayed, or when repairs areprolonged. Furthermore, it will be possible toinform owners and management companies

TECHNICAL R EPORTS

· 17Septamber 2002

Software Structure

System Structure Diagram

Printer

Database

Settings for the three types of processing software can be changed for each command console client. As a result, installation operations and response to hardware failures are simplified.

Following is our recommended structure:- Command console clients #1 and #2 are set up for command console client operations and REP communications software; it is possible to perform on-screen operations of command consoles while receiving signals from REP.

- Command console Client #3 is set up solely with data collection software, and operates exclusively as a collector of remote surveillance data.

(In cases where there are few elevators under management, it is possible to jointly use remote surveillance clients.)

(Receipt of fault data, abnormal signals, etc.)

(Receive panel)REP#1

(Receive panel)REP#2

(Receive panel)REP#3

Normal usage

Backup Voice communication device

Direct conversation device

For screen prints

Command console Client #1 (install software 1 and 2)

Command console Client #2 (install software 1 and 2)

(Data collection for remote maintenance)

Command console Client # 3 (install only software 3)

Remote maintenance: Client # 1 (Shows results of remote

maintenance in printed form)

Field mechanics and branch office

Router

Printer for maintenance results

Server

Internal PBX

(On call receiving)

(Current status supervision) Orders for dispatching engineer - completion reports etc.

PublicTelephone network

Customer

Backup

Normal usage

Printer data switch

Used exclusively for data collection; no operations done here

Data

Servicing for each clientMonitoring of each client

ORACLE Access97 SOCKET OCX

ORACLESQL NET

ORACLESQL NET

SOCKETOCX

SOCKETOCX

REPOCX

Command console clientCommand console client operation software

REP communications software

Data collection software

Confi-guration software

Hardware, networks and underlined software items to be arranged for locally

Remote maintenance client

Editing and output software for remote maintenance results

Windows NT 4.0 Server Windows NT 4.0 WS Windows NT 4.0 WS

MOP (Monitor Panel)

Fig. 1 Description of the overseas MIC/Remote Maintenance System

immediately in response to their inquiries onhow faults are being handled.

These capabilities are the basis for the powerfulappeal of this system to customers, for it enablesswift response to breakdowns, and its installationwill provide them premier elevator performance.

BREAKDOWN STATISTICS/ANALYSIS (an exporttool). Through this export tool, it is easy to ac-quire the necessary data from accumulated cus-tomer information, elevator specificationinformation and fault data that has been enteredinto the system.

TECHNICAL R EPORTS

Mitsubishi Electric ADVANCE18 ·

The resultant quick and easy analysis andcollection of data on fault details makes it pos-sible to provide rapid support for data feedbackto the manufacturer and proposals to reduce therecurrence of faults.

Remote Maintenance System

NOTIFICATION OF FAULTS AND ABNORMALCONDITIONS. This function automatically noti-fies the call center when elevators malfunction.

In addition to the details of the malfunction,information on the floor where the malfunctionoccurred and data on factors that may be pre-sumed to have caused the malfunction is alsoprovided.

This function has made it possible to maxi-mize the unique capabilities of microcomputersand so to carry out continuous remote electronicmonitoring twenty-four hours a day, 365 days ayear. This is very different from the necessarilyfragmentary inspections normally carried out byour maintenance staff, and offers major benefitsas a public relations tool with respect to cus-tomers.

VOICE COMMUNICATION FUNCTION. This func-tion permits conversation over a communica-tions device between people trapped in theelevator and personnel in the call center, shoulda malfunction result in entrapment or an eleva-tor be rendered inoperable.

Since this allows command center personnelto transmit appropriate instructions to peopletrapped in the elevator, those entrapped can feelreassured, and content to wait until help arrives.

REMOTE MAINTENANCE FUNCTIONS. Here wehave two types, irregularity-detection functionsand performance data-recording functions. Theirregularities of “ irregularity detection” (ormovement diagnostic) functions are notsituations where a fault has occurred, butsituations where a temporary logical con-tradiction may arise from contact-point signalsand/or where bad input/output signals may beencountered within the control unit due todeterioration over time, wear and tear and grime.Such irregularities also include situations whereeven though elevator systems are functioningnormally under regular operating conditions,they may not function properly under emergency

conditions, impairing safety and functionality.By their very nature, it is extremely difficult

to track down such irregular conditions duringregular on-site inspections. Based on analysesof data gathered over time that identify thecourse of events preceding malfunctions, modelby model, we can now detect such conditionsby using an operational diagnostic program us-ing structured logic.

PERFORMANCE DATA-RECORDING FUNCTIONS.Measuring such things as the number of opera-tions and duration of current flows as well asthe number of door openings and closings at eachfloor for the equipment installed, yields infor-mation that is vital in drawing up elevator in-spection, maintenance and replacementschedules. Through this process, it is possibleto identify elevator abnormalities that are ontheir way to creating breakdowns and to rapidlycarry out the appropriate preventive mainte-nance.

Furthermore, when there is a persistent inci-dence of irregular data, the elevator transmitsirregular signals/data to the call center. Main-tenance personnel analyze the reasons for theirregular data received, and then can carry outeffective preventive maintenance, implementingaction plans based on their analyses.

Since elevators have an important role as ameans for vertical transportation within cities,we must maintain their functioning and safetyat a high level at all times. For this purpose, inJapan the corporation has set up and is operat-ing a system capable of remote monitoring formore than 200,000 elevators under its manage-ment.

Based upon our experience within Japan, wehave developed an overseas version of the MIC/Remote Maintenance System. It has already beeninstalled in a number of countries and is pro-ducing clearly evident benefits. In view of theseresults, and in concert with the overseas salesactivities of Mitsubishi Electric, from the cur-rent fiscal period on the corporation will run acampaign to promote use of this system and todetermine its proper positioning, moving aheadto enhance and expand the maintenance activi-ties of affiliated overseas businesses.

R & D P R O G R E S S R E P O R T

· 19September 2002

*Satoru Kato is with Inazawa Works and Jun-ichi Higaki is with the Advanced Technology R&D Center.

by Satoru Kato and Jun-ichi Higaki*

The World’sFastest Elevators

High-rise buildings are more popular thanever. This trend is driving progress to improvethe performance of the elevators that providevertical transport in tall structures. Shuttle el-evators and double-deck elevators have also comeinto favor. Rising to the challenge, MitsubishiElectric Corporation has developed both theworld’s fastest elevator, which travels at an ul-tra high-speed 1,080m/min, and a high-speed,high-capacity elevator that can carry loads ofup to 4,800kg at 600m/min.

Along with the development of high-perfor-mance traction motors to hoist and lower theelevator cars and control systems to operate thetraction motors, increasing the speed of eleva-tors also entails taking care to ensure that pas-sengers can ride in comfort at extremely highspeeds of 1,000m/min. It was also necessary todevelop technology to minimize vibration andnoise within the cars.

This article shows how new technologies havebeen implemented in the creation of the world’sfastest elevators.

High-Capacity Traction MotorsMitsubishi Electric usually classifies as high-speed elevators those that travel faster than120m/min. For this class of elevator we werethe first company in the industry to adopt theuse of PM (permanent magnet synchronous)motors, which combine excellent efficiency withquiet operation. These days, PM motors havecome to be used for nearly all high-speed eleva-tors.

In the case of the ultra high-speed elevatorsdiscussed in this article, when the shaft lengthexceeds 400m, the mass of the hoisting ropesand the car contribute to mechanical inertia,making it too large compared with general el-evators. Consequently, to accelerate and decel-erate the elevator, we needed a motor thatwould be able to exert very large torques.

This led to the adoption of a double-windingthree-phase design for the PM motor. This wind-ing method involves creating, in a single motorunit, a double coil around the iron core. Thistandem method and miniaturization give anexcellent structure. Moreover, the independentwinding of each coil enables use of twin controlsystems for parallel-drive control.

Fig. 1 shows both the external view of a trac-tion motor that incorporates a double-windingthree-phase motor for high-speed, high-capacityelevator applications, and its control system.

Fig. 1 The traction motor and its control system

Drive-Control SystemFig. 2 shows the configuration of the controlsystem for a high-speed, high-capacity elevator.Parallel drive control is configured so that eachof the main circuits is controlled independentlyand this increases the degree of design freedomfor the layout of the control panels. The inverteruses six IGBT (insulated gate bipolar transistor)modules rated at 600A connected in parallel. Asingle unit of this type of control equipment isable to handle operation of an elevator rated fora speed of 540m/min and a load of 4000kg.

In the parallel control system, the inverter con-troller has both a single-speed controller and twoelectrical-current controllers. Control takes intoaccount mutual interference between the twocoils of the double-winding three-phase motor.This enables very precise control of tractionmotor speed and torque, thus ensuring a com-fortable ride.

The converter controller maintains a constantDC voltage supply to each part of the drive sys-tem. The phase of the power supply voltage isdetected, and the power factor of the outputcurrent is maintained at 1 (unity) during pow-ered operation and at -1 during regenerative op-eration.

Vibration-Damping EquipmentComfort during the running of high-speed eleva-

R&D PROGRESS REPORT

R & D PR O G R E S S R E P O R T

Mitsubishi Electric ADVANCE20 ·

Converter

ACR

ACR ACR

Currentfeedback

Currentfeedback

Currentfeedback

Currentfeedback

Inverter

ACR

G/D

G/D G/D

G/D

PM Sheave

Counterweight

Car

Speedfeedback

INVERTERCONTROLLER

CONVERTERCONTROLLER

DC voltagefeedback

DC voltagefeedback

Control system1 (Inverter controller)

Control system 2 (Converter controller)

KEYPM : Permanent magnet synchronous motorG/D: Gate driver, ACR: AC-Reactor

Fig. 2 Configuration of the control system.

tors largely determined by car vibration. Whenriding inside the car, passengers are particularlysensitive to lateral (horizontal) vibration, whichis often experienced as discomfort. Lateral vi-bration primarily results when deformed orslightly misaligned guide rails generate a per-turbing force on the car. The higher the carspeed, the higher the perturbations become, thusincreasing the strength of vibration.

In the past, to reduce the vibration, oil damp-ers and other passive devices were introducedto the guide shoe or located between the eleva-tor car and the frame. Additionally, the greatestcare is taken to increase the precision of guiderails during machining and to improve align-ment accuracy during installation to minimizethe perturbing force.

With the prospect of high-speed elevators trav-eling at more than 1,000m/min, however, therewas concern whether these conventional pas-sive-damping systems would be able to ad-equately control vibration. Moreover, along withincreasing technical difficulties, it has becomeprohibitively expensive to specify more precisemachining of guide rails and implement furtherimprovement in alignment accuracy. Conse-quently, for these high-speed elevators, it wasnecessary develop new technology for reducinglateral vibration.

As a next-generation vibration damping sys-tem for high-speed elevators, the corporation hasdeveloped both an active roller-guide system tosuppress vibration originating at the guide railand an active control system installed between

car frame and platform to suppress car vibrationby using electromagnetic actuators. A descrip-tion follows of the active-control system that isinstalled between car frame and platform spe-cifically designed for high-speed elevators.

Structure of the Active-Control SystemBetween Car Frame and PlatformFig. 3 is a mimetic diagram of the active-controlsystem that was developed. Actuators are in-stalled under the car floor between the platformand car frame. The actuators reduce vibrationinside the car by using accelerative feedbackfrom an accelerometer (sensor) fitted in the car.The actuators make use of electromagnetic at-traction. This enables the small device to applya powerful force. Moreover, because the driving

Electromagneticactuator

Cage

Cageplatform

Yoke Coil

Accelerometer

Platform rubberDisplacementsensorCage frame

Fig. 3 Active control system under the cageplatform.

R & D P R O G R E S S R E P O R T

· 21September 2002

force does not require contact, the system hasthe advantage of avoiding the effects of floor sink-age caused by fluctuations in car loading.

Compensation for Non-LinearityThe disadvantage of using an actuator thatmakes use of electromagnetic attraction as de-scribed above is that because of the gap betweenthe coil and the pole, the force of electromag-netic attraction is non-linear. This causes prob-lems with effective control. To deal with thisissue, an eddy-current sensor is used in this sys-tem to monitor the gap between the coil andpole. Data from the sensor is processed to com-pensate the current values and linearize the driv-ing force.

Vibration-Suppression Control SystemFig. 4 is a block diagram showing the vibration-suppression control system. The equation usedto regulate vibration control is shown below.

Fm = − KvTi + KpTi2

Gh(s)Gl(s)x1 Eq. 1 Tis+1 (Tis+1)2

..

Non-linearitycompensation D/A Amplifier Electromagnet

Elevatormechanical

system

Display sensorcompensation

g(x1-x2) Displacementsensor Accelerometer

ControllerKv

i* Fm x1-x2 x1x1-x2

x1

F*m

--

x0: Displacement of guide rail

Kp 1/S 1/S A/D LPF

i

x2

x1,

Fig. 4 Block diagram of active control systeminstalled between car frame and platform.

This concludes our introduction to some of thetechnology associated with the successful de-velopment of the world’s fastest high-speed el-evator, operating at 1,080m/min. Practicalachievement of excellent ride comfort was basedboth on the expertise that Mitsubishi Electrichas accumulated in past development of high-speed elevators and on familiarity with the lat-est technology. The corporation is committedto meeting the needs of the world for the mostadvanced forms of vertical transportation.

0.13m/s2(pp)X-direction

-0.1

0

0.1

Acc

eler

atio

n [m

/s2 ]

0.11m/s2(pp)Y-direction

-0.1

0

0.1

Acc

eler

atio

n [m

/s2 ]

Time [sec](a) Without control

Time [sec](b) With control

0.05m/s2(pp)X-direction

-0.1

0

0.1

Acc

eler

atio

n [m

/s2 ]

0.06m/s2(pp)

-0.1

0

0.1

Acc

eler

atio

n [m

/s2 ]

Y-direction

0 5 10 15 20 25

0 5 10 15 20 25

Fig. 5 Test results of floor active control

Here, Kv is feedback gain for the acceleration ofthe car and Kp is feedback gain for the positionof the car. By optimizing these, the vibration ofthe car is suppressed. Furthermore, Gh(s) is alow-cut filter to attentuate the DC componentof vibration and Gl(s) is a low-pass filter to re-duce high frequency noise from the accelera-tion sensor.

Results of Trial OperationPractical trials with an actual test elevator werecarried out using the actuators and control equip-ment described above.

Fig. 5 shows test measurements of X vector(left-right) and Y vector (front and back) motionof the car with and without active-vibration con-trol. It is clear that application of the controleffected a 50% reduction in vibration.

TECHNICAL HI G H L I G H T S

Mitsubishi Electric ADVANCE22 ·

*Manabu Ogura is with Advanced Technologies R&D Center and Yasumasa Haruta is with Inazawa Works.

by Manabu Ogura and Yasumasa Haruta*

Escalators with High-SpeedInclined Sections

A basic technology has beenstablished for the inclined sec-tions of high-speed escalatorscapable of increasing the step-moving speed within these sec-tions by 1.5 times the correspond-ing step-moving speed at thelanding sections.

Based on the new technology,a one-fifth scale model (Fig. 1) wasfabricated and this confirmed thatbasic operations such as chang-ing speed, reversing, etc., can beperformed without any problems.This is the world’s first such scalemodel.

If high speeds can be achievedin the inclined sections of anescalator, the hitherto irrecon-cilable aims of securing highsafety while getting on or off theescalator and of minimizing thetime spent on the moving esca-lator itself can both be achieved.

Also, if the inclined section is

Fig. 2 An expanded view of the upper landing of an escalator withhigh-speed inclined section

Main track

Folding link

Folding point Step link roller

StepRiser

Trailing track

Trailing roller

Assistant roller

Assistant track

Fig. 1 A one-fifth scale model of an escalator with high-speed inclinedsection

run at normal speed, this can becombined with a slow-runninglanding section, forming a verysafe escalator that is easy on theelderly, children, etc.

The speed is changed by ex-panding and contracting thefolding links that connect adja-cent steps using a cam mecha-nism comprised of rollers and

tracks so as to change the spacebetween the steps (see Fig. 2).For the practical implementationof this mechanism, we are cur-rently evaluating the possibilitiesby analyzing dynamic simula-tions of step acceleration duringspeed changes, drive resistance,etc., and by optimizing the shapesof the cam (track), the preciselocation of the turning-back(folding) point of the steps, etc.

Issues requiring future work arethe development of a variable-speed handrail system and theexamination of safety when walk-ing on the steps.

TECHNICAL HIGHLIGHTS

T E C H N I C A L H I G H L I G H T S

· 23September 2002

*Teruo Konno and Naoya Yamada are with Mitsubishi Electric Building Techno-Service Co., Ltd.

by Teruo Konno and Naoya Yamada*

Diagnostic & Support Equipment for theInsulation of Traction-Machine Motors

We have developed insula-tion evaluation support equip-ment that analyzes the state ofinsulation from detailed, conve-niently gathered measurementdata. This equipment can bebuilt into a support system thatenables assessment of deterio-ration and estimation of remain-ing service life.

Accumulated data for dielec-tric breakdown and insulationdiagnostics has been built intoa database. This allows statisti-cal estimation of the remainingservice life.

In the past, it has been custom-ary to rely on meggers (megohm-meters) to measure insulationresistance. In-depth evaluation ofinsulation called for separatelyacquired data for DC absorptioncurrents and dielectric loss tan-gents. This method involvedpainstaking work and effectiveassessment required expert analy-sis, so it was seldom used on site.

As part of a company that hasbeen delivering increasing num-bers of traction machines overthe past two decades, we set outto develop a system that wouldenable regular maintenancestaff to diagnose the degree ofdeterioration of insulation intraction-machine motors. Thisequipment is described below; aphotograph is shown as Fig. 1.

First, we list the main specifi-cations of the diagnostic equip-ment used by the support system.

Insulation resistancemeasurementRange: 0.1~10,000MΩPreliminary measurement:at 250V DC (for 1min)Normal measurement:

Fig. 1 External view of the diagnostic equipment

at 500/1000V DC selectable(for 1min)

Current measurementRange: 0.01µA~10mAMeasurement voltage:500/1000V DC selectable

Dielectric loss tangentmeasurementRange: 0.1%~60%, 1~100nFMeasurement voltage:100~500V AC variable,50/60Hz.

As well as being able to mea-sure the normal one-minutevalue for insulation resistance(in Megohms), a more accurateassessment of the characteris-tics of the insulation materialactually used in the motor canbe obtained by measuring DCabsorption current (attenuationcharacteristics of leakage cur-rent) so as to yield the polariza-tion index (PI: an indicator of theattenuation of DC absorption

current).Furthermore, the equipment

analyzes the AC dielectric losstangent and shows its voltagedependency.

For more convenient on-siteuse, the equipment automati-cally evaluates insulation resis-tance, followed by currentabsorption, and then dielectricloss tangent without needingthe operator to switch connec-tions. Insulation resistance datais graphically represented on thedisplay panel and recorded on acomputer diskette (see Fig. 2).

The insulation evaluation sys-tem does more than gather data.Besides on-screen displays of theresults of maintenance checkdata, fuzzy logic is employed toapply to the data the same cri-teria used by expert technical di-agnosticians. Following thesediagnostic rules, the state of in-sulation deterioration (assessed

TE C H N I C A L HI G H L I G H T S

Mitsubishi Electric ADVANCE24 ·

Insulation resistance measurements and indicatorsPreliminary measurement at 250V for 60s, 452MΩNormal measurement at 500V for 60s, 463MΩWeak point ratio 1.0

Service office K service office

Type of service contract M F

Control number 11234

Machine number 02

Equipment type D M N

Model number M G 246 DB

Evaluated part Stator

Date manufactured Feb. 1973

Date evaluated 7 Nov. 2000

Building name Building A

Weather Cloudy

Temperature 28.0˚C

Humidity 67%

Environment Good

2.50

2.00

1.50

1.00

0.50

0.00

10

8

6

4

2

0100 200 300 400 500

0 21 3 4 5 6 7 8 9 10

RecommendationThe insulation resistance measurement looks favorable, but taking into account the PI and tan δ measurements, we may infer that contamination has already started and that the presence of voids makes moisture absorption possible.

PI Measurement (at 500V, 10min)

Cur

rent

(µA

)

Time (minutes)

Tan Measurement (at 500V)

Tan

δ (

%)

AC Voltage (V)

δ

tan δ = 4.45%tan δ = 0.83%Co = 71.0nF

∆

PI = 1.08µA/0.94µA= 1.2

UpDown

Fig. 2 Typical insulation measurement results

T E C H N I C A L H I G H L I G H T S

· 25September 2002

Fig. 3 Typical diagnostic display

grade) can be evaluated (see Fig.3). Note: This display is onlyavailable in Japanese.

To evaluate remaining servicelife, the system collects and ana-lyzes correlations between 820measurements concerned withinsulation characteristics and 150for breakdown voltage (BDV).

The system is able to providean averaged grade for assesseddeterioration from the valuesgathered by the insulation evalu-ation system. It also reveals com-paratively good correlationsbetween the BDV of the arma-ture, stator, field magnet, rotorand other components of theelectric motor.

Consequently, using these cor-relations, regression lines can bederived for each tested componentand, from the yielded residualBDV values, an estimate can bemade of remaining service life.

Analysis of the deteriorationreveals regression lines for de-

terioration and residual BDV toyield 95%, 90%, and 50% reli-ability assessment grades, thusenabling estimation of remain-ing service life (see Fig. 4a and4b).

Based on the lower limit (BDV)breakdown voltage shown in thegraph (Fig. 4b),the difference be-tween the present 50% regres-sion line value and the 90% or95% reliability shows estimatedresidual BDV.

The results of this system fordiagnosing the insulation dete-rioration of the motors used forelevators provide insight intothe state and form of deteriora-tion and they enable techniciansto recommend specific coursesof action. The results conformwell with those obtained by ex-pert technical diagnosticianswho use conventional methods.Moreover, we have verified goodcorrelation of results for esti-mated residual BDV and on-sitemeasurements of BDV.

Building name Building C

Access number 12345

Machine number 01

Machine type 175CS

Part evaluated Armature coil

Date manufactured April 1980

Date evaluated April 2001

Number of indicator 6

Rated voltage 220V

Days in use 7,668

Residual breakdown voltages50% reliability 2,573V90% reliability 595V95% reliability 198V

Estimated remaining service life50% reliability 5.5 years (2,010 days)90% reliability 3.0 years (1,105 days)95% reliability 1.4 years (494 days)

RecommendationThe results of remaining life assessmentsuggest that this motor is approaching theend of its service life. Deterioration in theinsulation as a result of ageing suggeststhat the motor should be replaced withinthe next year or two.

Table 1 Data and Recommendation for Fig. 4

TE C H N I C A L HI G H L I G H T S

Mitsubishi Electric ADVANCE26 ·

Fig. 4 Typical displays for estimated remaining service life

As this insulation diagnosticequipment and insulation evalu-ation support system goes intomore widespread use, its effi-cacy will be further proved,leading to still further applica-tions. This will help to ensurethe reliable operation of rotarymotors and aid customer to ap-propriately schedule the neces-sary repairs and preemptivereplacements.

100

80

60

40

20

0

10000

8000

6000

4000

2000

00 20 40 60 80 100

0 3000 6000 9000 12000 15000

90%95%

90%

95%

Det

erio

ratio

n gr

ade

(%)

Days of use

(b) Estimating reductions in residual BDV

BD

V (V

)

50% Regression line90% reliability

95% reliability

Lower limit BDV

Insulation deterioration grade (%)

Present

Present

(a) Statistical estimates of remaining service life

· 27September 2002

NEW PRODUCTS

MELART-II; New Full-Color Paint Finish

In December, 1995, MitsubishiElectric created a precedent in theindustry by introducing the use ofcomputer graphics for painted steelelevator panels. These MELARTpanels have provided elevators withdistinctive finishes ever since. How-ever, increasingly diversified build-ing designs and the role of elevatorsas the main portals by which peopleenter buildings have given rise todemand for even more individualis-tic and original, better-crafted de-signs.

In response, the corporation hasmade fundamental changes to theprevious method of producingMELART panels, increasing thegraphic resolution for these largepanels from 400dpi to 720dpi. Im-provements have also been madeto the light-resistance of the finish,and MELART II options now extendto gloss and semi-gloss (or matte)full-color finishes.

The new panels use a specialprinting process to create thermo-setting films of paint combined withtechnology to ensure that thesefilms can be “baked” onto the metal

surfaces, creating full-color steelpanels. This avoids the need forplate making as in silk-screen print-ing, and is ideal for short productionruns of many variants.

The technology for these paintedfinishes is proprietary, and the sub-

New Home Elevators

Since starting to manufacture homeelevators (private residenceelevators) in 1988, Mitsubishi Elec-tric has installed an impressivenumber of these units; over 16,000within Japan and hundreds over-seas. The corporation’s new homeelevators meet the demand for high-speed drives, which is particularlystrong in overseas markets.

The large buttons on the car-operating panel provide easy-to-use control and the machinery itselfhas been downsized and lightened,making home elevators as easy onthe environment as they are easy touse. A typical car design is shownin Fig. 1.

The basic (standard) specifica-tions are for three passengers,stopping at up to four floors (rise tobe 10m or less), with decoratedsteel panels providing both rigidityand high quality for the car anddoors. Ventilation fans, mirrors,handrails and dual openings areavailable. The compact designsmake minimal requirements forspace: installation is possible in aspace only 1.5m wide by 1.5m deep(a special machinery room is un-necessary).

The features of the new elevatorsare as follows:

Fig. 1 An elevator door showingthe beautiful color finishpossible with MELART II.

Speed has been increased fromthe previous 12m/min to 20m/min,shortening operation time to 60%.Although the rated speed has beenincreased 1.7 times, the develop-ment of low-noise motors, a newwinding machine and an improvedcontroller means that vibration andnoise characteristics are compara-ble with the previous elevators.

The Mitsubishi emergency land-ing device (MELD) system forpower failure is supplied withbatteries and a charger asstandard. Owners can therefore feelsafe in using these elevators.

Single-phase 200V AC power isrequired, but different voltages canbe accommodated in individualdesigns within the range 210 to240V AC.

Installation of these home eleve-ators is easier and can be complet-ed faster than for previous elevatorsthanks to the adoption of the front-rail installation system. In this sys-tem, the guide rails are installed onthe front-entrance side of the eleva-tor shaft wall by means of brackets,after which the entrance units aremounted on the guide rails.

Fig. 1 A typical car design

ject of pending patent applications.It also has many potential applica-tions beyond elevator panels.MELART II panels have thefollowing characteristics:

MELART-II reproduces beautifullyand with complete fidelity and sta-bility traditional Japanese paintings,geometrical figures created by silkscreen printing, and graphic illus-trations.

Well-suited for small-lot produc-tion of many product variants,MELART-II also has the clear ad-vantage of undergoing only half thefading of automobile finish coatingsunder exposure to ultravioletradiation.

MITSUBISHI ELECTRIC CORPORATIONHEAD OFFICE: MITSUBISHI DENKI BLDG., MARUNOUCHI, TOKYO 100-8310, FAX 03-3218-3455