Mechatronic Systems

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Course 5: Mechatronics - Foundations and Applications

Introduction to Mechatronics and Mechatronics in Real Life Maria Popovchenko May 29, 2006

Abstract

Mechatronics is a natural choice for explaining a process that seeks, from the outset, to generate definitive engineering system solutions, which are inextricably bound by those integrating technologies associated with the inveterate mechanical, electronic and computer based disciplines discip lines.. Mechatron Mechatronics ics opens op ens up enormous enormous technologi technological cal possibilities possibilities,, as already already evidenced evidenced by the appearance of sophisticated products like ever-smaller camcorders and compact disc players. play ers. These would would never never have been plausible plausible by adopting adopting a traditional traditional single disciplinary disciplinary or combin combinati ational onal appro approac ach. h. By definition definition,, then, then, Mechat Mechatron ronics ics is not a subject, subject, scienc sciencee or technology per se - it is instead to be regarded as a philosophy - a fundamental way of looking at and doing things, and by its very nature requires a unified approach to its delivery. The traditional western approach has relied on single discipline identities and evolutionary solutions solutio ns based on bolt-on b olt-on technology technology.. On the other hand, Mechatronics Mechatronics solutions require require the use of integrate integrated d teams of person p ersonnel nel working working towards a common goal. Thus Thus the Mechatron Mechatronics ics engineer engine er identifies identifies with systems thinking, thinking, and a philosophy philosophy that lies behind it all. A Mechatronicss ’product’ tronic ’product’ derived derived through through systematic, systematic, rather than piecemeal piecemeal processing. It, therefore, therefore, seeks to optimize an ’engineered’ solution rather than compromise it. Mechatronics philosophy adequately adequat ely describes the process by which it is achieved. achieved. This insight insight quite naturally naturally lends itself to the concept of ’total quality’, something that western industrialized nations have only in the last decade decade or so come come to aspire aspire to. But for Mechatr Mechatroni onics, cs, quality quality is alread already y imp implie lied d by the way in which system based solutions are to be sought, and the methodologies used for achieving achi eving it. It is hoped that industry and commerce commerce will similarly similarly come to respect respect and aspire to Mechatronics for what it stands for - total synergy.

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Contents 1

Introduction

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Principles of Mechatronic Systems Construction

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Modern Trends of Mechatronic Systems Development

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Levels of Mechatronic Systems’ Integration

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Career Paths in Mechatronics

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Introd trodu ucti ction

The word mechatronics was first introduced by the senior engineer of a Japanese company [1]; Yaskawa, in 1969, as a combination of ”mecha” of mechanisms and ”tronics” of electronics, and the company was granted trademark rights on the word in 1971. The word soon received broad acceptance in industry and, in order to allow its free use, Yaskawa decided to abandon his his righ rights ts on the word word in 1982. 1982. The The wor ord d ha hass taken taken a wide widerr mean meanin ingg si sinc ncee th then en,, and and is now widely used as a technical jargon word to describe a philosophical idea in engineering technology,, more than technology technology technology itself. For this wider concept of mechatron mechatronics, ics, a number number of  definitions has been proposed in scientific literature, differing in the particular characteristics, which whi ch each definit definition ion is in inten tended ded to emphas emphasize ize.. The most common commonly ly used used one emphas emphasize izess synergy: syner gy: Mechatroni Mechatronics cs is synergistic synergistic integration integration of mechanica mechanicall engineering, engineering, electronics electronics and intelligent computer control in design and manufacture of products and processes. The developmen developmentt of mechatron mechatronics ics has gone through through three stages. The first stage corresponds to the years years when this term was introduced. introduced. During During this stage, technologi technologies es used in mechatroni mech atronicc systems systems developed developed rather independent independently ly and individually individually.. With the beginning beginning of the eighties, a synergistic integration of different technologies started taking place, the notable example is optoelectronics optoelectronics (i.e. an integration integration of optics and electronics). electronics). The concept of  hardware/s hardw are/softw oftware are co-design co-design also started in those years. years. The third and the last stage can also be considered considered as the beginni b eginning ng of the mechatronic mechatronicss age since early ninet nineties. ies. The most notable aspect of the third stage is the increased use of computational intelligence in mechatronic product prod uctss and systems. systems. It is due to this this develop developmen mentt that we can now now talk about Machine Machine Intelligence Quotient (MIQ). Another important achievement of the third stage is the possibility of miniaturization of components; in the form of micro actuators and micro sensors (i.e. micro mechatronics).

Figure 1: Mechatronic Mechatronic system architecture architecture

A mechatr mechatroni onicc system system has tw twoo main main compone component ntss as shown shown in Figure 1. The control controlled led system is a mechanical process that is in contact with the environment by mean of all its sensors and actuators. Distinguishing features of the mechatronic system are three sub-systems of the controlling system used for perception, knowledge representation, planning and control. The intelligence intelligence is usually usually embedded embedded in the planning and control control sub-system. sub-system. Thus, Thus, based on

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information taken from the sensors, computational intelligence methods are exploited to plan a course of action that will enable the controlled system to achieve any given task. Conventional microprocesso microp rocessors, rs, artificial artificial neural neural networks, networks, fuzzy logic and probabilisti probabilisticc reasoning reasoning are among the tools used in the sub-system for information processing and decision making.

Figure 2: The functional diagram of semiotics

Figure 3: The six-box diagram of behavior formation Recently, a wider concept, concept of ”semiotics” is still proposed as a new paradigm of  science in the 21st Century. It is defined as a theoretical field which analyzes and develops formal tools of knowledge acquisition, representation, organization, generation and enhancement, communicat comm unication ion and utilization. utilization. The functional represent representation ation of semiotics semiotics given in Figure 2, is differen different, t, (and it is more more descri descripti ptive ve)) than of Figure Figure 1 and, and, theref therefore ore,, displa displays ys the link between betw een semiotics semiotics and mechatronics. mechatronics. The same figure, is drawn as a six box diagram, it can be used to describe the behavior behavior formation of living creatures and mechatronic mechatronic systems. systems. In each box of Figure 3, the same six-box diagram can be inserted, it indicates a multiresolutional hierarchy. There are some mechatronics’ definitions published in periodicals and international conferences reviews. Having studied above mentioned definitions, the following special formulation is offered. ”Mechatronics studies synergistic fusion of precise mechatronical units, electronic, electro technical and computer components for the purpose of designing and manufacturing qualita-

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tively new modules, systems, machines and complexes of machines with intellectual control of  their functional movements ” [2]. Comments to the definition: 1. Mechatron Mechatronics ics studies special methodological methodological (conceptual) (conceptual) approach to construction construction of  machines mac hines with qualitatively qualitatively new character characteristic istic features. features. It is important important to emphasize, that this approach is rather universal and can be applied to machines and systems of  various purposes. purposes. Howeve However, r, it is necessary necessary to note, that the only way to maintain high quality ofobject. mechatronic system (MS) control is to takeics into account specificity of a scertain operated It is reasonable reason able to study mechatronics mechatron according accordi ng to its specialties specialtie which have definite classes of industrial machines and processes as their subjects; 2. The definition emphasizes synergetic character of components’ integration in mechatronic objects. objec ts. Synerg Synergy y is a mutual mutual action taken taken to achie achieve ve a goal. goal. It is very very importan importantt to mention men tion that the compone component ntss of the later system system not only only impro improve ve each other, other, but beingg united bein united in such such a way way, they they bring bring qualit qualitativ atively ely new propert properties ies to the system. system. In mechatronics all power and information flows are directed to the only one goal - to perform a set operated movement; 3. Integr Integrate ated d mechat mechatron ronic ic compone component ntss are alway alwayss chose chosen n at the design designing ing stage, stage, nec necesessary engineering and technological support are provided at manufacturing and applying stages. It explains a considerabl considerablee difference difference between between mechatronics mechatronics and traditional traditional machines, when a user has to combine various mechanical, electronic and informationoperating devices from different producers into one system at his own discretion; 4. Methods of parallel parallel designing (concurren (concurrentt engineering engineering methods) serve serve as methodological methodological basis for mechatron mechatronic ic systems developmen development. t. At traditional traditional designing designing of machine machine with computer control consecutive design of mechanical, electronic, sensor and computer parts of the system is carried out before choosing interface interface block blocks. s. The paradigm of parallel parallel designing consists of simultaneous and interconnected synthesis of all system’s components; 5. The main ob objec jects ts that mechatr mechatroni onics cs studies studies are: are: mechatr mechatronic onic modules modules that, that, as a rule, rule, move mo ve on one operated operated coordin coordinate ate,, sophis sophistic ticate ated d system systemss of modular modular archit architect ecture ure are assembled from such modules as if these were functional cubes; 6. According According to the definition, definition, mechatroni mechatronicc systems are intended intended to perform a set movemovement. men t. Qualitativ Qualitativee criteria of MS movement movement performance performance are problem-focused, problem-focused, i.e., defined fine d by statemen statementt of a certai certain n applie applied d task. task. Specific Specificit ity y of automat automated ed mechan mechanica icall engineering tasks consists in moving a target part of working body of the technological machin mac hinee (e. (e.g., g., a tool for machin machining ing). ). Thus, Thus, it is necess necessary ary to coordin coordinate ate spatial spatial MS movemen mov ementt together together with various various external external processes. processes. Regulation Regulation of force interaction interaction between working body and the object at machining, diagnostic and control of MS critical components, control of additional technical influences (thermal, electric, electrochemical) on the object at combined methods of processing, operating auxiliaries of the complex delivery (conveyors, loading devices) and reception of signals from electro-automatic devices (valves, relay, switches) can serve as examples of such processes. Such complicated and coordinated MS movements can be called functional movements; 7. In modern MS methods of advanced advanced intelligen intelligentt control are used to secure secure high quality quality in performing complicated and precise movements. These methods base on new ideas of  managing real theories, modern equipment and software and perspective approaches to synthesis of operated MS movements. Being a new branch of modern science, mechatronics doesn’t have strictly stated terminology, definite bodies and classification characteristics. Revealing the sense of new principals of construction and new trends of machine developme dev elopment, nt, with their movement movement controlled controlled by computer, computer, is crucial. Not a long time will elapse before all notions and definitions are formulated.

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Princ Principl iples es of Mechat Mechatron ronic ic Syst Systems ems Const Construc ructio tion n

When MS performs a set functional movement, the objects render revolting influences on the working body [3]. We can study, as an example of such influences, cutting forces for machining processes, contact forces and moments of forces at assembly, reactive force of the liquid jet at hydraulic cutting. We can roughly divide environmental surroundings into 2 basic classes: determ and non-determ. non-determ. We can classify environment environmental al surroundin surroundings gs as determined determined when their revolting influence parameters and characteristic features of the object can be determined beforehand so accurately that it is possible to design a mechatronic system. Some environmental surroundings are non-determined due to their nature (as extreme environmental surroundings: underground or underwater), characteristic features of technological environmental surroundings, as a rule, can be determined by means of analytic-experimental research and computer modeling methods. E.g., to estimate estimate cutting forces at mach machining ining process series series of experiment experimentss on special research installations are carried out, vibration influence parameters are measured on vibration test bench with subsequent creation of mathematical and computer models of  revolting rev olting influences leaning on experimenta experimentall data. However, to organize and to carry out similar researches expensive equipments and measuringg technologi surin technologies es are required. required. So, for preliminary preliminary estimation estimation of force influences influences on working working body at robotized barr removal from cast products it is necessary to measure actual shapes and parameters of each half-product. In such cases it is expedient to apply methods of adaptive control which allow to correct automatically the laws of MS movements in the course of  operation.

Figure 4: The functional diagram of semiotics

The structure of a traditional machine includes the following basic components: mechanical device with the working body as its final part; block of drivers with power converters and executive engines; computer control device, the top level of which is an operator or another

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computer with computer network access. Sensors are used to transmit information on actual condition of machine blocks and MS movement into controling device. Thus,, these 3 obligatory Thus obligatory parts (mechanic, (mechanic, electronic electronic and computer) connected with power power and informative flows is a primary characteristic feature that distinguishes mechatronic system. Electro mechanic part includes: mechanic links and transmissions, working body, electric motors,, sensors motors sensors and some additional electro-tech electro-technical nical elements elements (brakes (brakes and couplings). couplings). Mechanical device is used to transform movements of its parts into required movement of the working body.

Figure 5: Examples of mechatronic systems

As it shown in Figure 5 the computer disk drive is one of the best examples of mechatronic design because it exhibits quick response, precision, and robustness. According to mechatronic principles clothes washer features a sensor-based feedback control that maintains correct water temperature no matter the load size. The electrical part consists of micro-electronic devices, power converters and measuring cir circui cuitt electr electroni onics. cs. Sensor Sensor controls controls are intended intended to obtain obtain data about actual actual conditi conditions ons of  environment surroundings and objects of processing, mechanical device, blocks of drivers with subsequen subse quentt processing processing and transmitting transmitting of this information information to computer control device. Top level lev el computer computer and controller controllerss of movemen movementt control control are integral parts of mechatroni mechatronicc system. system. Computer control device carries out the following basic functions: 1. Control Control of mechanical mechanical movemen movementt process in mechatronical mechatronical module or in multi-meas multi-measured ured system on-line with current sensor data analysis. 2. Arrangemen Arrangements ts to control control MS functional functional movements movements that is to coordina co ordinate te simultaneously simultaneously MS mechanical mechanical movements movements and external external processes. Discrete Discrete input/output devices devices are always used for external process control. 3. Interactio Interaction n with operator via human-mac human-machine hine interface interface off-line and on-line interactio interaction n at the moment of MS movement. 4. Data exchange exchange betw b etween een peripheral devices, devices, sensors and other devices of the system. The main task of MS is to transform input information from the top level of control into purposeful purpose ful mechanical mechanical movemen movementt with its control control based on principle of feedback. feedback. It is notable that electric power (less often hydraulic or pneumatic) is used as intermediate power form in modern systems. The core of mechatronic mechatronic approach approach consists consists in integratin integratingg of two or more components probably of different different physical physical nature into a uniform functional module. In other words words,, at the stage

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of designing one interface, as a separate device, is excluded out of a traditional structure, but physical essence of transformation carried out by this module is kept. As an ideal variant, from the user’s point of view, mechatronic module, having received input information on the purpose of control, will carry out the set functional movement with desirable qualitative parameters. Hardware integration of components into uniform constructivee modules tiv modules should should be accomp accompani anied ed by develo developme pment nt of in integ tegrat rated ed softw software are.. MS softwa software re should provide direct transition from a project of the system to functional movement control of the system by means of mathematical modeling. Application of mechatronic approach at creation of machines with computer control defines their basic advantages in comparison with traditional means of automation: •



  Rather low cost owing to a high degree of integration, unification and standardization of all elements and interfaces;   Ability Ability to perform complicated complicated and precise precise movement movementss (of high quality) quality) owing to application intellectual control methods;



  High reliability, durability and noise immunity;



  Constructiv Constructivee compactness compactness of modules (up to miniaturizat miniaturization ion in micro machines); machines);





 Improved overall dimension and dynamic characteristics of machines owing to simplification of kinematics’ kinematics’ circuits; circuits;  Opportunity to rebuild functional modules to sophisticated systems and complexes according to specific purposes of the customer.

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3 Modern Modern Tren Trends ds of of Mec Mechatron hatronic ic Syst Systems ems Develo Developpment World production of MS is constantly increasing and expands new spheres. Today mechatronic modules and systems find wide application in the following areas [4]: •

  Machine-t Machine-tool ool construction construction and equipment equipment for automation automation of tec technologi hnological cal processes; processes;



 Robotics (industrial and special);



  Aviation, Aviation, space and military techniques; techniques;





 Motor car construction (for example, antiblocking brake system (ABS), systems of car movement stabilization and automatic parking);  Non-conventional vehicles (electro bicycles, cargo carriages, electro scooters, invalid carriages);



 Office equipment (for example, copy and fax machines);



  Computer facilities (for example, printers, plotters, disk drives);



  Medical equipment (rehabilitation, clinical, service);



  Home appliances appliances (washing, (washing, sewing and other machines); machines);



  Micro machines (for medicine, biotechnology, means of telecommunications);



  Control Control and measuring measuring devices and mac machines; hines;



 Photo and video equipment;



 Simulators for training of pilots and operators;



  Show-industry (sound and illumination systems).

Impetuous development of mechatronics as new scientific and technical direction in the 90ies was caused by a lot of factors among which there are the following key factor factors: s: trends trends of  global industrial development; development of fundamental basic and mechatronic methodology (the base scientific ideas, essentially new technical and technological decisions), activity of experts in research and educational spheres. It is possible to distinguish the following tendencies to change and key requirements of the world market in the considered area: •









  Necessit Necessity y for production and service service of equipment equipment according according to the international international system of the quality standards stated in the Standard ISO 9000;  Internationalization of scientific and technical production market and, as a consequence;   Necessit Necessity y for active introduction introduction of forms and methods of internati international onal engineering engineering and puttingg new technologi puttin technologies es into practice;   Increasing role of small and average industrial enterprises in economy owing to their ability to quick and flexible reaction to changing requirements of the market;   Rapid developme development nt of computer computer systems systems and technologi technologies, es, telecommun telecommunication ications, s, especially in the countries countries of the European Community Community. Intellect Intellectualiza ualization tion of mechanical mechanical movement control systems and technological functions of modern machines appear as a consequence of this common tendency.

The analysis of these specified tendencies shows that it is impossible to achive a new level of the basic process equipment following traditional approaches. Development of mechatronics as interdisciplinary scientific and technical sphere besides obvious technique-technological difficultie difficul tiess also also has a lot of new manageri managerial al and economic economic problems problems.. Modern Modern enterpri enterprises ses starting to develop and produce mechatronic products should solve the following fundamental problems:

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  Structural Structural integration integration of mechanica mechanical, l, electronic electronic and information information departments departments (which (which as a rule, work independently) into a uniform creative staff;   Education and training of engineers specialized in mechatronics and managers able to organi org anize ze in integ tegrat ration ion and supervi supervise se work work of strict strictly ly special specialize ized d experts experts with with differe different nt qualifications;  Integration of information technologies from various scientific and technical fields (mechanic, electronics, computer control) into a uniform toolkit to provide computer support of mechatronic problems;   Standard Standardiza izatio tion n and unificat unification ion of all used used elemen elements ts and process processes es at des design igning ing and manufacturing mechatronic systems.

Solution of the listed problems frequently demands that we should put an end to traditions, which were established in management before, that the average managers, who got used to solve sol ve only partic particula ularr proble problems, ms, should should ov overc ercome ome their their ambit ambition ions. s. For this this reason reason av avera erage ge and small enterprises, which have flexible structure, turned out to be more prepared to start manufacturing mechatronic production.

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Levels Levels of of Mec Mechatron hatronic ic Syst Systems ems’’ Integ Integrat ration ion

In mechatronics it is reasonable to accept a level of integration between MS elements as a basic characteri characteristic stic feature [5]. According According to this feature it is possible possible to divide divide mechatronic mechatronic systems taking into account their generations, if consider their presence in the market of high technology production from historical point of view. Mechatroni Mech atronicc modules mo dules of the first level level integrate only two initial elements. elements. Motor-reduc Motor-reducer er can serve serve as a typical example example of this module. In this system mechanical mechanical redu reducer cer and operated engine are issued as a uniform functional element. element. Mechatron Mechatronic ic systems based on these modules found wide application at development of various means of complex automation in industrial production (conveyors, rotary tables, auxiliary manipulators). Mechatronic modules of the second level appeared in the 80ies when new for that time electronic technologies, which allowed to produce tiny gauges and electronic blocks for signal process proc essing ing were were being being develo developed. ped. Drivin Drivingg modules modules in integ tegrat rated ed with with specifie specified d elemen elements ts led to mechatronic modules of movement with their structure completely corresponding to the definition mentioned above, when integration of three devices that are different by their nature: mechanical mech anical,, electro electro technical technical and electronic electronic is achieve achieved. d. On the basis of mechatron mechatronic ic modules of the given given class class operated operated power power machin machines es (turbi (turbines nes and genera generator tors), s), machin machinee tools and industrial robots with numerical program control have been created. Development of third generation mechatronic systems is caused by presence of rather inexpensive microprocessors and controllers produced on their base in the market. Development of  these MS is directed to intellectualization of all processes taking place in mechatronic system, firstt of all - process firs process of functi functiona onall move movemen mentt contro controll in machin machines es and units. New principl principles es and technologies for precise and compact mechanical units are being developed together with new types of electric motors (first of all high moment, collector-free and linear), feedback and information inform ation gauges. Synthesis Synthesis of new precise, precise, information information and measuring measuring high technologi technologies es gives a basis for designing and producing intellectual mechatronic modules and systems. In the future mechatronic machines and systems will be united into mechatronic complexes on the base of uniform integration platforms. The purpose of creation of such complexes is to achieve a simultaneous combination of high efficiency and flexibility of technique-technological environme envi ronment nt due to its ability to reconfigurate reconfigurate,, that will allow to provide provide competitiveness competitiveness and high quality of production on the markets of the XXI century.

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Care Career er Pat aths hs in Mec Mechatr hatron onic icss

The field of mechatr mechatroni onics cs is now now widely widely recogni recognized zed in all parts of the world world [6]. Various arious undergraduate and graduate degree programs on mechatronic engineering are being offered by different universities. Mechanical Mech anical engineers engineers are often at a loss to communicat communicatee and understand understand the issues issues electrical engineers and the software specialists bring up. The idea is to get rid of the uncertainties associated associate d with electronics electronics and computers. computers. It means to develop develop people who are comfortable comfortable making the necessary trade-offs among a wide range of approaches based on the given design constraints. With a focus on these kinds of skills, mechatronics is seen as a prime career path for mechanical mech anical engineers engineers of the future. I believe believe that mechanical mechanical engineers engineers with a mechatron mechatronics ics background will have a better chance of becoming managers. Mechatronics is a career for the future mechanical engineers. Classically trained mechanical engineers will run the risk of being left out of the interesting work.. These people will have much work much more of a chance chance to lead. Mechanical Mechanical engineers engineers who know some computer science are far more valuable than the computer scientists who know some mechanical mech anical engineering. engineering. Mechanica Mechanicall engineers engineers have a better feel for the overall overall system and do a better job of making the crucial trade-offs. One possibility is that mechatronics practitioners will prototype the whole design, then, specialists in various disciplines will take over the detail design.

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References [1] Poduraev Poduraev U.V. U.V.  Fundamentals of Mechatronics . STANKIN, 1999. [2] Auslander Auslander D.M. D.M.  Mechatr  Mechatronics: onics: A Design and Implementation Methodology Methodology for Real Real Time  Control Software . DRAFT, 1997. [3] www.me.berkeley.edu. www.me.berkeley.edu. [4] www.imec www.imeche.org he.org.uk. .uk. [5] www.memagazi www.memagazine.or ne.org. g. [6] www.me.uw www.me.uwaterloo.c aterloo.ca. a.

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