AIAA-94-1252-CP

SLMP_G APP!.,!CATIONS SOF'IWARE

FOR VISION GUIDED ROBOT IMPLEMENTATION

Charlie Duncheon

Adept Technology, Inc.

San Jose, California

Abstract

This paper begins with the background on how

robotic implementation has flourished in Japanwhile only moderately growing in United Statesmanufacturing. Contributing reasons areprovided with focus on the constraint of the timeand difficulty of robot applications software.Particular focus is made on the largest robotapplication segments in the world markets,

material handling and assembly. Manufacturingdemands of the 1990's are cited and scenarios

of 21st century plants are described. Successfulimplementation of vision guided robots for theseplants is described by use of the followingsystem building blocks:

1. An industry standard form factor, openarchitecture hardware control platform.2. A proven and integrated real time operatingsystem and factory automation language withinthe platform that provides direct support forsophisticated motion control and real timesensing.3. A building block, icon/menu basedapplication software approach for both

developing applications and for easy factoryfloor interface.

4. An open architecture platform that allowsother proven operating systems and/or cellcontrol hardware/software solutions to coexist

on the same back plane with the coremotion/vision operating system.

Backm'ound

Despite robot technology being invented in theUnited States, the implementation rate in the USmarket fell behind that of the Japanese by tensof thousands of robots per year by the end ofthe 80's. The trend continued in 1993 despite a

new parity in the cost of capital between US andJapan. New "Agile Manufacturing" thrustshave emerged in US manufacturing yet they are

Copyright © 1993 American Institute of Aeronautics andAstronautics, Inc. All rights reserved.

noticeably short of true flexible automationstrategies. In the early 80's Prudential Bache

projected a US robot business of $2 billion by1990. The market actually reached $500 millionin the early 90's. The current installed base ofindustrial robots in Japan is 400,000 units,while in the US it is only 50,000 units. Japaninstalls more robots per year than the totalinstalled base in the US.1

Why the slow adaptation of industrial robotsand flexible automation in the US compared tothe continuing robust growth in Japan? First ofall, Prudential Bache was correct in identifying$2 billion of robot applications that should havebeen implemented in the US. In fact, it wouldhave been even more had the technology beenimplemented at the Japanese rate. Thefundamental constraint to growth of the robotindustry was the difficulty in implementing thetechnology. Suppliers overestimated the time,capacity and technical skill level manufacturershad to implement automation. Financialjustification followed the same parameters asapplied to traditional hard automation, leading toonly the most challenging applications gainingfinancial approval. This only compounded theproblem of successfully implementing the-technology in manufacturing.

A study by Adept Technology, Inc. 2 showed

that in the 1980's the cost to design, write,debug and document application software wasas high as 50% of the total robot system costs.

And for the most part the software developedwas custom to each application. Applicationsoftware development, debug, andimplementation was also determined to be a

common bottleneck to system implementationschedules. Other robot companies and robotsystems integrators have come to the same

conclusions and have taken steps to standardizeapplication software. In 1992 and first half1993 statistics released by the Robotics

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https://ntrs.nasa.gov/search.jsp?R=19950005107 2018-06-06T04:35:34+00:00Z

Industries Association show healthy increases inthe implementation of robots in the US market,due in part to more enabling software. 1992orders for US based robot manufacturers grew21.5%, and first half 1993 orders jumped40%.1

This paper will discuss how the utilization ofexisting and proven hardware and softwaremodules which minimize custom software

development cannot only increase US robotimplementation beyond the current improvedrates, but put the US in the global lead. Therewill be no formulas or equations; manufacturingengineers who are our vital hope forcompetitiveness have no time for such. Theyhave plenty of their own process algorithms toaddress. They care about practical suggestionsthat allow them to address the cost and qualityissues without compromising lead time tomarket. That is what this paper will attempt toaddress.

Manufacturing Forces of the 90'8

There are many forces influencingmanufacturers today but three _n__ ,,........ ._llltllll [I.$1lKd_ _J.4_tltdt

out that will determine global manufacturingstrategies:

1. World Class Quality - World classquality is not an option but the price ofadmission for those manufacturers who want to

survive the decade. The "Six Sigma"commitment by Motorola is one of the more

publicized commitments to this imperative.

2. Minimum Life Cycle Costs - The 90'sis being dubbed as the "value decade", asmanufacturers constantly evaluate theirmanufacturing costs against global competitors.As governments realign the world markets viaNAFTA, GATF and EC agreements, even thosemanufacturers who limit themselves to domestic

markets will see global competition in theirhome markets.

3. Minimum Product to Market Times -

The laptop computer used to write this paper iscurrently nine months old and has already beenobsoleted by a higher performing model.

Conventional high volume, low mix productionstrategies are in conflict with this force.Manufacturers are being challenged to have

shorter changeover times or running multipleproducts simultaneously on the same line. Onepower supply manufacturer has an objective thata customer can specify a custom power supplywith a lot size of one and receive it within one

day, built with flexible automation.

Unfortunately, the above three forces havetraditionally been in conflict with each other.Automation might have addressed quality forcesbut did not support rapid lead time to markets.Traditional robot automation may not have metcost objectives. And many US companiesfound that offshore labor did not meet qualityrequirements.

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The RIA and its member companies believe thatthere does not have to be a tradeoff among theseforces. The belief is that properly applied,"Agile Automation" can "shrink' the triangle oftradeoffs.

Adept Technology, Inc has developed a longrange strategy for minimizing flexibleautomation cell implementation and changeovertime with the development of vision guidedflexible feeding technologies and modularfunctional and application software. These

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Rapid DeoloymQnt Automation

Objective: Conservation of Time

System Implementation

Specifications

Programming

Editing

Debug

Product Changeover

Years

iI

System MTTR

Diagnostics

efforts are part of Adept's overall vision of"Rapid Deployment Automation".

Rapid Deployment Automation is an overallstrategy focused at reducing the time, andthereby the cost, required to implement flexibleautomation. Given that systems typically cost2x the direct hardware costs, Adept feelsstrongly that reducing engineering content willbe a primary driver to reducing the cost offlexible automation. Rapid DeploymentAutomation also address directly the productchangeover / time to market issues discussedabove.

Flexible feeding is a key element in RapidDeployment Automation, as by nature it reducesthe amount of hard tooling in a robot cell, whichreduces costs and promotes rapid development

of cells. 3 Flexible feeding replaces traditional

part specific feeding systems such as bowlfeeders and precision dunnage with intelligentsensor based robotic application software.Sensing is provided by integrated machinevision and real time force sensing, which areused to locate random or loosely oriented partson simple conveying or infeed systems.Flexible Feeding software includes modules and

algorithm's to locate the parts, determine theirorientation, control the conveyors andrecirculating devices, and acquire and place the

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parts. The Flexible Feeding concept, and thespecific software modules that drive it, areexamples of how software can dramaticallysimplify the overall engineering task in a flexibleautomation cell.

21st Century. Factories

If Adept and other RIA companies aresuccessful, the following scenario is possible

for the year 2000 manufacturing assemblyplants:

1. Small, nimble plants, less than 250

employees, located close to consumer bases ofpopulation or major OEM customers.

2. Lot size of one, same day delivery tocustomers. Rapid changeover from one part to

another and rapid implementation of incrementalprocess and component part improvements andchanges.

3. Vision guided robot and flexible feeder basedproduction. Limited investment in hard tooling.Intelligent software based feeding and fixtudng.

4. No software language based programmingwithin factories. Simplified set up of highlyintelligent software modules with imbedded

process knowledge by floor personnel.

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How Do We Meet the Challenge?

One way we will not meet the challenge is tocontinue to develop application software and/ormotion control platforms "from scratch" becauseof what appears to be unique or process specificrequirements. The development cycles forapplications will exceed the product cyclesthemselves. The approach certain robot andsystems suppliers are taking is to providefunction and application software modules thatserve as building blocks to the final lineapplication program.

This modular approach to software developmentis not new. There are countless libraries todayof software functions from various hardware

and software vendors. The burden in usingmodular libraries is in the linkage betweenmodules. This fine tuning still requires highlyskilled programmers, and significant time. Thenew approach is to provide these moduleswithin a structure or framework that defines

how the modules work together. Unlike objectoriented programming, which offers a similarstrategy, this new generation of factoryautomation software includes mgn'-'..... rove1interfaces and process knowledge about thetasks themselves to allow setup by non

programmers. 4

The best way to describe such an approach iswith an application. Assume we have a dentaladhesive applicator product with a cylindricalbody with one open end, an impeller that mustinsert into the body, and a cap that must beinserted at the top of the body and impeller. Thebody arrives open end up in multiples on a traymoving on a roller conveyor and stops againstan activated fixture. The dunnage that carriesthe body is general purpose, and does notprovide significant precision in locating thebodies. The manufacturer is dealing with aproduct with a short life cycle and wants toquickly reuse the robot, grippers, feeders, andsoftware when any of the three pans change indesign. A single vision guided flexible feederfor the impellers and caps, and vision guidedregistration of the bodies in the trays along with

inspection for acceptable inner body diametersare among the cell design parameters.

The long path to a solution would be to interfaceone supplier's vision system and language witha second motion system and language, withcustom software written in C, perhaps on a PC

platform. Not only is the development cyclelong, but history has shown debug activity for

this approach to extend well past floorimplementation.

This potentially ill fated path relates to a lack ofempathy of many developers with regard to"real time" in a robot cell on the factory floor vs.that in the work station environment.

Deterministic, multitasking operating systemsthat can do context switching in micro secondsare crucial when expensive grippers withexpensive parts are on a collision path. Moreimportant than part and gripper damage, systemdowntime is unaffordable. Manufacturers like

Toyota and Michelin are requiring 40,000 hourMTBF performance from equipment suppliers.In other words, bugs or errors at the workstation are manageable, but unacceptable on theassembly floor.

The integrated control platform offers a muchlower cost, schedule time, and risk approach tothis solution. A platform that has thousands

successfully running applications while keepingmotion, vision and force sensing, andcommunications software under one language is

the optimum place from which to start for thisapplication. 5

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An Adept control platform that control's Adeptrobots or any other robot mechanism would be

made up of "wrung out'_functional softwaremodules that build into an overall applicationsmodule. These functional modules are menu

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driven and utilize a common data base structure and common global variables. Modules are tied together to create the specific application module, imbedding any necessary process knowledge, by use of the high level V+ programming language. Adept's standard functional modules and tools for vision and force guided assembly are represented by icons. Adept's patented AIM (Assembly Information Manager) environment allows the developer to create additional linked icons as required to represent combinations of Adept modules and any application customization or process imbedding.

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Example of Robot Cell Software Structure

/ Integrated

Adept Integrated Controller |V+ Factory Automation Language

AIM Application Software Packages /lr

Motion / Vision

Module

Linkage toMIS

Vision InspectionModule

Part Data

Bases

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So the impcUer assembly application can bequickly developed with bug free softwaremodules which also leave an rational user

interface for modifying on the factory floor.Now let's assume the manufacturer has strict

FDA requirements for Statistical ProcessControl records and has invested heavily in aPC based SPC program that he wants to applyto any workstation. The Adept MV controllercontains a standard VME back plane with openslots for other boards. The manufacturer canhave a VME board with an imbedded PC

inserted on the Adept back plane andcommunicate as required with the Adeptoperating system and AIM. Customization is

limited to defining what variables arc needed bythe SPC module.

The approach describedhereissimple: Usecommercially availablesoftwareand hardware

wherever possibletominimize system costs,schedules,and risks. There isan abundance of

softwareand hardware technology thatdoes not

have to be reinvented. This approach is whatput the Japanese in a leadership role in the 80's.The US now can do the same with a much more

flexible array of vision guided robottechnologies.

\!\01 j

1. Robotics Industries Association, Ann Arbor, Michigan.

2. Adept Technology internal integration study. November, 1989.

3. G. Orelind, "Flexible Part Feeding for Robotic Workcclls", Robotics Wodd, Summer 1993.

4. J. Campbell, P. Cencik, "General Purpose Scalable Motion / Vision Controllers", Proceedings,ISTA Conference on Lean Manufacturing, August 1993.

5. J. Campbell, '"The Economics of Utilizing an Integrated Control Hatform for OEM MotionControl", Motion Control, February 1993.

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