metodologias de desarrrollo de robots

Development methodology for manufacturing ofcommercial robots

Rolando Cortes-Martinez, Eduardo Vazquez-Santacruz and Mariano Gamboa-ZunigaCentro de Investigacion y de Estudios Avanzados del I.P.N.

Coordinacion General de Tecnologıas de la Informacion y las ComunicacionesAv. I.P.N. No. 2508, Col. San Pedro Zacatenco 07360, Mexico, D.F., Mexico.

Tel.: (52)-55-57473800 ext. 6819Email: efvazquez, [email protected]

Abstract—In this paper is presented a methodology and a caseof study in which a final commercial product is developed. Itis presented all the stages and timings throughout which theproduct is defined and manufactured. Also, a description ofthe interactions among multidisciplinary groups is explained insome detail. The case of study is an assistive robot for hospitalenvironment usage. The main areas or participating groupsare: industrial design, manufacture and mechatronics. The maincontribution is the description of the whole project logistics andcoordination with a complete technician view.Index � terms :logistic; development process; robot;methodology.

I. INTRODUCTION

The development process for manufacturing of final orcommercial product projects covering from the planninguntil the manufacturing step implies various stages and theinteraction between multiple disciplines, administrative andoperative ones. For this paper we are focus on the operativeissues.

The case of study in this paper is a real case of developmentof product. Some details and characteristics are mentionedbut because of confidential and commercial issues some otherdata will not be addressed. For the purpose of the paper thereader will assumes that prototype is a robot which aims tohelp patient with a degree of handicap to do some daily livetasks or to help in rehabilitation. Such a robot is thought towork in hospital environment.

II. METHODOLOGY

Multiple factors interact in the kind of methodology tobe employed for a company or development team to reachthe culmination of a final product. Although a generalmethodology may not serves for all kind of projects,companies or budgets it could serves suffering minormodifications. Some of the factors which make differencebetween development projects are for instance the complexityof project, the infrastructure and human resources, thedeadlines, the budgets, among others [5]. As a starting pointwe employed the scheme proposed in such reference modifiedas seen in Fig. II-B.

A. Planning

This stage has to be carried out with a multidisciplinaryteam, a central team integrated mainly by the leader and someengineers suitable for the project. Depending on the nature ofthe project it also could be made up of health care specialist,psychologist, market expert, financial expert, someoneresponsible of acquisitions, etc. During this stage also anothertasks take place like: defining positions and responsibilities,doing interviews, hiring personal, defining organizationalstructure, setting objectives and deadlines, calculating costs,etc. If possible the first approaches to concept definition mustbe made and finding possible component suppliers also isdesirable.

A good planning is crucial for the whole projects success, itmust be studied seriously although many tasks and deadlineswill be modified by the dynamic of project during thedevelopment. A period of 1 up to 2 weeks is recommendedfor planning. A Gantt diagram is necessary with differentpossible scenarios if possible.

B. Concept definition

The concept definition is a development in which theproject starts gaining form, here is done a revision of state ofthe art and some field studies are carried out with surveys andinterviews with medics, patients, nurses, and patient relatives.The objective is to obtain the final user requirements thatwill constitute the goals to attain for the teamwork. Also isrecommended to do an intellectual search in patent databasesand to do a benchmarking with the leader companies in thecurrent market.

Fig. 1. Project stages

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C. Functional design

The functional design implies to have a full solutionintegrated on computer at simulation level. Different areaswork concurrently here to find solutions, such as electronics,mechanics, software development and control. A majorgoal for every team is to obtain a list of components to beemployed by the final prototype in short time because timefor acquisitions may be constrains for further stage starts. Insome cases the components will be fully identified; howeverin other cases there will be uncertainty in the proficiencyof them to solve the problem in question, thats why it isrecommended to have a list of different components thatlikely could solve the same problem. Applies the popular saidBetter to have too much than too little.

At the same time some interaction between functionaldesign and industrial design is carried out, this is an iterativeprocess in which we obtain a compromise on both areas.

D. Manufacturing

Finally, once and only when design in paper andcomputer is good enough to cover the requisites exposed themanufacturing process takes place. As a result we have afirst prototype, which represents the first approach to a finalcommercial product.

The prototype then must be evaluated in the real workspaceunder real conditions, for this task is required a formalprotocol developed by medics specialists in heath. From thisprotocol we obtain feedback from final users and a secondstage of technical modifications must be done.

Although this paper only deals with the operative issuesis important to mention that some basic administrative rulesneed to be acknowledge to coordinate the whole complexityof project, some guides followed are [4] and [1].

III. APPLICATION OF METHODOLOGY

In this section we give some details of the application ofmethodology described above.

A. Planning based on deadline, 12 months

For this project was taken 1 week for the planning process,and the team was made up of: the leader, 1 health carespecialist, 1 industrial designer and 1 mechatronics engineer.During this period were defined the number of participants aswell as the way of recruitment. The latter was carried out inthe next 2 weeks. The human resources were distributed asshown in table 1 and organized as in Fig. 1. In the table isnot mentioned but there is another group strongly importantfor the whole project, the hospital personal: more than 100medicals, 100 nurses and 40 stretcher-bearers participated inthe project by means of interviews, surveys and proofs ofconcept (PoC). Besides the medical group it is also important

to look for information in statistics obtained from officialreports, magazines and research groups related with the illnessto be treated [6].

TABLE IPERSONAL REQUIRED

Personal requiredstage group Positions

Planning Initial Central group

1 leader1 health specialist1 industrialengineer.1 mechatronicengineer.

Concept Same as above plus:

definition, 2 mechanicengineers

functional Final Central 1 electronicengineer

design and group 2 mechatronicengineers

and assemble 1 logisticassistant.2 software engineers1 coordinator

Industrial Industrial 2 industrialdesigner

design design team 2 industrialdesigner students1 graphic designer

Manufactu-ring Local company 1 coordinator1 mechanic engineer4 workers

Components 4 companies.acquisition

The Gantt diagram was programmed initially for a projectduration of 9 months, however for several reasons thereal durance was of about 12 months. This time is verysignificant compared to the years, even decades of researchand development that actual leader market companies carryout to obtain similar results to ours for same kind of product.The initial Gantt diagram (Fig. III-A) had a total of 27 tasksalthough many modifications were applied to it, resulting in agrowth in number of tasks up to 126 as well as modificationin nature of tasks. A total of 23 major updates were carriedout to the original plan. The final diagram is not presentedbecause of space reasons.

Fig. 2. Organization


As seen in Fig. III-A the tasks are simultaneous in somepoints, that means it is not necessary to finish one task tostart the next one. That is valid for many tasks and helps toaccelerate the processes.

B. Concept definition of our robot.

The concept definition was carried out by the final centralgroup in 2 weeks. During this period the more important goalis to obtain the general requirements of our robot. This isdone by elaborating surveys and interviews with the personalof the hospital. Also is needed to observe how they use thetraditional equipment intended to be replaced by the robot.More than 200 surveys were employed.

After we obtained the information it is processed andtranslated into technological problems to be solved. Thisgives us a list of general and specific requirements that servesas design objectives. A list of 52 user needs was obtained.They were classified by hierarchy depending on the numberof times it was mentioned by the hospital personal or theimportance for them.

The first scratches are carried out by the engineers toattend the most important demands on the previous list.

C. Functional designg.

For this project the following areas were required toobtain a functional design: Electronics, Mechanics, Softwaredevelopment. The duration of this stage was of about 3months, at the end of this period the 3 teams finished afirst design to be evaluated and improved by manufacturingengineers feedback.

1) Electronics.: The first step was to set the objectivesin terms of this area, then the team started a search ofcomponents, sensor and actuators which could fit therequirements. A first list of components was ready after thefirst month, among others the list contained the processor, adata acquisition board (DAQ) and some sensors with unknownbehavior. Then, a general diagram using the top-down designphilosophy was taking form. By the second month most ofthe components were defined and the simulations and PrintedCircuit Board (PCB) designs took place. A handbook ofrobotics [3] is useful for this stage as a first approach atlooking for sensors and actuators.

2) Mehanics design: A similar process took place forthe mechanics design, here an extensive use of ComputerAided Design (CAD) were done and an strong basis offundamentals is needed [2]. At the end of the 3 months acomplete design included a kinematic analysis, bears analysisby finite element, selection of mechanical elements, locationof actuators, collision analysis and limits of movementanalysis. The first approach in the complete mechanical

design didnt include an exhaustive manufacturing revision.

Fig. 3. Gantt diagram initial

3) Software development.: One of the major contributionsof the prototype is the artificial intelligent module, this offersan outstanding advantage over other similar products. Theteam in charge interacted strongly with electronics teambecause the electronics team was in charge of the logiccontrol of the robot whereas the software development teamworked specifically in the intelligent part. Another reasonfor this strong interaction is the fact that the software readsinformation of a matrix array of sensors read by the electronicmodule. The design was complete after 3 months since thispart required more research than the others. (Fig. III-C2)

After 3 months a firs approach to the final functionaldesign was completed, however during the depuration wasnecessary to start interactions with the external teams such asindustrial design and the manufacturing company. Thus thedesign never ends and is constantly getting improvements butevery change in one area have to be informed in advance tothe other areas for a whole synchronization to be attained.

IV. MANUFACTURING

The company of manufacturing offered a service ofcorrective manufacturing, it means, that the company isresponsible for providing solutions to technical problemsencountered during manufacturing that implies changes in theoriginal design. The central team is responsible for taking thefinal decisions over the proposed solution and for updatingthe original CAD. This job, took over 1 month of negotiationand then over 7 months of manufacture and adjustments.

A. Industrial design

The industrial design team initiate its job 1 month beforethe functional design was completed, at this time werecarried out logistics and form of interaction with the centralteam. The major job started when the functional design was


culminated in its first approach. With this information theteam works in two main objectives: study the usability of therobot and the cosmetic view of it.

The team finished its design 3 months after receiving thefunctional design in computer. Then they work iterativelytogether with the central team in order to do the updates totheir design as result of the modifications by the manufactureintervention. There is also a stage of manufacturing for theindustrial team because they were in charge of their ownpieces, the pieces that covers the whole prototype a gives acosmetic image. The time of manufacturing of these pieceswas about 1 month and was culminated at the same time themechanical structure.

V. ASSEMBLE

Assemble of the main mechanical structure was madeduring the manufacturing process, so at the end of month 11were done. Also, during that period the electronic team as wellas the industrial designers did partial proofs of assembling inorder to correct any mistake in design. Once the companyof manufacturing presents the structure the electronics teamproceeds to do the general wiring and components allocation.This task takes 2 days in a full time basis and the priorityis to proof that all systems works properly. Once verifiedthe correct functionality of electronics systems 2 weeks arerequired to formally allocate components and wirings. A totalof 200 wirings and allocation of over 45 components wereassembled for this project.

When the electronics team did the first functional proofsin the assembled mechanical structure, the industrial designengineers assembles their pieces in the robot. Minormodifications took place.

Finally, when all prototype was assembled a series offunctional proofs were done in order to ensure the correctfunctioning of all parts. This job is carried out by the centralteam and takes about 2 weeks.

VI. STUDY CASE

Using this methodology development, we have built a robotthat is useful for assisting older persons in full or motor prob-lems (Fig. VI). This device has required a multidisciplinaryteam involving medical staff experience, mechatronics experts,skilled mechanics, electronics experts, artificial intelligence,industrial design, graphic design and ergonomics. Besides thefundamental support of a team of administration, documenta-tion, procurement, suppliers of various products and servicesare required.

(a)

(b)

(c)

Fig. 4. An assistive robotic device for elderly people: a robotic bed

VII. CONCLUSIONS

As stated in the description above for a complex project likethis one results a big challenge to integrate multidisciplinaryteams and ensure a correct compliment of deadlines. Themain clue to bring that to a reality is to maintain a continuouscommunication among all teams and to follow strongly closethe advancements of every team. The methodology presentedhas proved to be success since the robot was successfullyintegrated and assembled; it has received good commentsfrom expert people in many areas and will soon be launched.

REFERENCES

[1] W. R. Duncan, A guide to the project management body of knowledge,1996.

[2] R. L. Norton, Diseno de Maquina. Prentice Hall, 4th Edition.[3] B. Siciliano and O. Khatib, Spinger Handbook of Robotics, 2008.[4] J. Sutherland, Scrum handbook. SCRUM training institute press, 2010.[5] Ulrich-Epinger, “Diseno y desarrollo de productos,” in Mechatronics and

Automation (ICMA), 2014 IEEE International Conference on, 3th edition2004.


[6] H. B. S. Workgroup, A Guide for Modifying Bed Systems and UsingAccessories to Reduce the Risk of Entrampment,FDA, 2006.

VIII. BIOGRAPHIE

Rolando CORTES MARTINEZ wasborn in Tlaxcala, Mexico on October27, 1979. He obtained a Master Dergreefrom Electrical Engineering Departmentof Cinvestav and the bachelors fromUniversity of Puebla (BUAP). He hasworked as professor for undergraduateprogrammes and he has worked for somecompanies developing mechantronics

projects. He participated in the camabot Project as a designerengineer. Currently is studying his PhD at Cinvestav. Hismain interests include attitude control of rigid bodies.

Eduardo VAZQUEZ-SANTACRUZwas born in Tlaxcala, Mexico. Doctorin Electrical Engineering and ComputerScience from the CINVESTAV-IPNin Mexico. From 2001 to date, he hasworked for Banamex, Softtek SweepstakesUDLAP Rassini Brakes, Netica Research& Technology, Cinvestav IPN, among

others. He has given several lectures in engineering andgraduate in some universities as UACM, Universidad delPedregal and Panamerican University in Mexico City andthe Autonomous University of Guadalajara in Oaxaca. Heparticipated as a founding member of Netica Research &Technology, the first technology development company drivenCinvestav IPN. In the business context, he has worked asa project leader of technology and applied research to SEPJalisco, Mixbaal SA de CV, Cinvestav IPN, among others.In cooperation with IPN Cinvestav and Juarez Hospital ofMexico, he coordinated the project of the first Mexicanassistive robot: a welfare robotics bed for Latin Americanhospitals.His areas of expertise involve pattern recognition, imageprocessing, artificial intelligence, intelligent systems,development of multidisciplinary projects and social impact ofprojects inherent in the knowledge economy. It has cooperatedin various projects with UNAM, IPN CINVESTAV, IPN,among other academic institutions to develop solutions tosocial impact.

Mariano GAMBOA-ZUNIGA wasborn in Zumpango, Mexico state. Doctorin Communications and ElectronicsEngineer from the LAAS-CNRS inToulouse, France. His employmentexperience included banker, researcher,teacher and consultant, Capital Investment

Funds, Business Development for MSMEs and InformationTechnology and Communications, marketing. His specialfields of interest included high-frequency bipolar transistors.His main achievements are the technology platform foronline education Open and Distance University of Mexico

(UnADM) to the Secretary of Higher Education of the SEP.,1500 Design and manufacture of electronic ballots for theFederal Electoral Institute (IFE), which were used in carryingout a survey in the presidential election on July 1, 2012,Implementation and operation of the largest and fastestCluster Xiuhcoatl of Mexico (3,480 cores, 9,200 gigabytes ofRAM and 47 Teraflops), Design and manufacture of high-frequency bipolar transistors, Creating pilot diodes and powertransistors, Discovery of the effect of ”Quasi-Saturation”and design configuration of the gate Power -MOS transistorto increase the value of the current. Discovery Effect ofsecond breakdown and circuit design protection MOS powertransistors.


metodologias de desarrrollo de robots

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