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315

Automati

Part C

Part C Automation Design:

Theory, Elements, and Methods

19 Mechatronic Systems – A Short Introduction

Rolf Isermann, Darmstadt, Germany

20 Sensors and Sensor Networks

Wootae Jeong, Uiwang, Korea

21 Industrial Intelligent Robots

Yoshiharu Inaba, Yamanashi, Japan

Shinsuke Sakakibara, Yamanashi, Japan

22 Modeling and Software for Automation

Alessandro Pasetti, Tägerwilen, Switzerland

Walter Schaufelberger (Δ), Zurich, Switzerland

23 Real-Time Autonomic Automation

Christian Dannegger, Rottweil, Germany

24 Automation Under Service-Oriented Grids

Jackson He, Hillsboro, USA

Enrique Castro-Leon, Hillsboro, USA

25 Human Factors in Automation Design

John D. Lee, Iowa City, USA

Bobbie D. Seppelt, Iowa City, USA

26 Collaborative Human–Automation Decision

Making

Mary L. Cummings, Cambridge, USA

Sylvain Bruni, Woburn, USA

27 Teleoperation

Luis Basañez, Barcelona, Spain

Raúl Suárez, Barcelona, Spain

28 Distributed Agent Software for Automation

Francisco P. Maturana, Mayﬁeld Heights, USA

Dan L. Carnahan, Mayﬁeld Heights, USA

Kenwood H. Hall, Mayﬁeld Heights, USA

29 Evolutionary Techniques for Automation

Mitsuo Gen, Kitakyushu, Japan

LinLin,Kitakyushu,Japan

30 Automating Errors

and Conﬂicts Prognostics and Prevention

Xin W. Chen, West Lafayette, USA

Shimon Y. Nof, West Lafayette, USA

316

Automation Design: Theory, Elements, and Methods Part C From theory to building automation machines,

systems, and systems-of-systems this part explains the fundamental elements of mechatronics, sensors, robots,

and other components useful for automation, and how they are combined with control and automation software,

including models and techniques for automation software engineering, and the automation of the design process

itself. Design theories and methods cover also soft automation, automation modeling and programming lan-

guages, real-time and autonomic techniques, and emerging networking and service grids for automation. Human

factors engineering and science in the design of automation, including interaction and interface design, and issues

of trust and collaboration focus on systems and infrastructures integrating people with decision-support and with

teleoperated, remote automatic equipment. Also in this part are advanced design methods and tools of distributed

agents, evolutionary techniques and computing algorithms for automation, and design of eight key automation

functions to prevent or recover from errors and conﬂicts, to assure automation reliability and sustainability.

317

Mechatronic S

19. Mechatronic Systems – A Short Introduction

Rolf Isermann

Many technical processes and products in the area

of mechanical and electrical engineering show

increasing integration of mechanics with digital

electronics and information processing. This in-

tegration is between the components (hardware)

and the information-driven functions (software),

resulting in integrated systems called mechatronic

systems. Their development involves ﬁnding an

optimal balance between the basic mechanical

structure, sensor and actuator implementation,

and automatic information processing and overall

control. Frequently formerly mechanical functions

are replaced by electronically controlled func-

tions, resulting in simpler mechanical structures

and increased functionality. The development of

mechatronic systems opens the door to many in-

novative solutions and synergetic effects which

are not possible with mechanics or electronics

alone. This technical progress has a very strong in-

ﬂuence on a multitude of products in the areas

of mechanical, electrical, and electronic engi-

neering and is increasingly changing the design,

for example, of conventional electromechanical

components, machines, vehicles, and precision

mechanical devices.

19.1 From Mechanical to Mechatronic Systems 317

19.2 Mechanical Systems

and Mechatronic Developments ............. 319

19.2.1 Machine Elements, Mechanical

Components ................................ 319

19.2.2 Electrical Drives and Servo Systems. 319

19.2.3 Power-Generating Machines ......... 320

19.2.4 Power-Consuming Machines ......... 320

19.2.5 Vehicles ...................................... 321

19.2.6 Trains ......................................... 321

19.3 Functions of Mechatronic Systems.......... 321

19.3.1 Basic Mechanical Design ............... 321

19.3.2 Distribution of Mechanical

and Electronic Functions ............... 321

19.3.3 Operating Properties..................... 322

19.3.4 New Functions ............................. 322

19.3.5 Other Developments ..................... 322

19.4 Integration Forms of Processes

with Electronics.................................... 323

19.5 Design Procedures

for Mechatronic Systems........................ 325

19.6 Computer-Aided Design

of Mechatronic Systems......................... 328

19.7 Conclusion and Emerging Trends ........... 329

References .................................................. 329

19.1 From Mechanical to Mechatronic Systems

Mechanical systems generate certain motions or trans-

fer forces or torques. For the oriented command of,

e.g., displacements, velocities or forces, feedforward

and feedback control systems have been applied for

many years. The control systems operate either with-

out auxiliary energy (e.g., a ﬂy-ball governor), or

with electrical, hydraulic or pneumatic auxiliary en-

ergy, to manipulate the commanded variables directly

or with a power ampliﬁer. A realization with added

ﬁxed wired (analog) devices turns out to enable only

relatively simple and limited control functions. If these

analog devices are replaced with digital computers

in the form of, e.g., online coupled microcomput-

ers, the information processing can be designed to

be considerably more ﬂexible and more comprehen-

sive.

Figure 19.1 shows the example of a machine set,

consisting of a power-generating machine (DC motor)

and a power-consuming machine (circulation pump):

(a) a scheme of the components, (b) the resulting sig-

Part C 19

318 Part C Automation Design: Theory, Elements, and Methods

Manipulated

variables

Measured

variables

Sensors

Actuator

Power

electronics

(actuator)

Power

generating

machine

(DC motor)

Power

consuming

machine

(pump)

Drive

train

(gear

unit)

PGM PCMDT

Auxiliary

energy

supply

Energy

supply

Energy

consumer

Primary

energy

flow P

Consumer

energy

flow P

Mechanics &

energy converter

Energy flowc)

Energy flow

Information flow

Sensors

Actuators

Auxiliary

energy

supply

Energy

supply

Energy

consumer

Primary

energy

flow

Consumer

energy

flow

Mechanics &

energy converter

Reference

variables

Monitored

variables

Manipulated

variables

Measured

variables

Information

processing

Man/machine

interface

Mechanical,

hydraulic,

thermal,

electrical

Fig. 19.1a–c Schematic representation of a machine set:

(a) scheme of the components; (b) signal ﬂow diagram

(two-port representation);

age; V

– armature voltage; I

– armature current; T –

torque; ω – angular frequency; P

– drive power; P

–

consumer power



nal ﬂow diagram in two-port representation, and (c)

the open-loop process with one or several manipulated

variables as input variables and several measured vari-

ables as output variables. This process is characterized

by different controllable energy ﬂows (electrical, me-

chanical, and hydraulic). The ﬁrst and last ﬂow can be

manipulated by a manipulated variable of low power

(auxiliary power), e.g., through a power electronics de-

vice and a ﬂow valve actuator. Several sensors yield

measurable variables. For a mechanical–electronic sys-

tem, a digital electronic system is added to the process.

This electronic system acts on the process based on the

measurements or external command variables in a feed-

forward or feedback manner (Fig.19.2). If then the

electronic and the mechanical system are merged to an

autonomous overall system, an integrated mechanical–

electronic system results. The electronics processes

information, and such a system is characterized at least

by a mechanical energy ﬂow and an information ﬂow.

These integrated mechanical–electronic systems

are increasingly called mechatronic systems. Thus,

mechanics and electronics are joined. The word mecha-

tronics was probably ﬁrst created by a Japanese engi-

neer in 1969 [19.1] and had a trademark by a Japanese

company until 1972 [19.2]. Several deﬁnitions can be

found in [19.3–7]. All deﬁnitions agree that mechatron-

ics is an interdisciplinary ﬁeld, in which the following

disciplines act together (Fig.19.3):

•

Mechanical systems (mechanical elements, ma-

chines, precision mechanics)

•

Electronic systems (microelectronics, power elec-

tronics, sensor and actuator technology)

•

Information technology (systems theory, control

and automation, software engineering, artiﬁcial in-

telligence).

The solution of tasks to design mechatronic sys-

tems is performed on the mechanical as well as on

the digital-electronic side. Thus, interrelations during

design play an important role; because the mechan-

Fig. 19.2 Mechanical process and information processing

develop towards a mechatronic system



Part C 19.1

Mechatronic Systems – A Short Introduction 19.2 Mechanical Systems and Mechatronic Developments 319

Fig. 19.3 Mechatronics: synergetic integration of different

disciplines



ical system inﬂuences the electronic system, and

vice versa, the electronic system inﬂuences the de-

sign of the mechanical system (Fig.19.4). This means

that simultaneous engineering has to take place, with

the goal of designing an overall integrated sys-

tem (an organic system) and also creating synergetic

effects.

A further feature of mechatronic systems is in-

tegrated digital information processing. As well as

basic control functions, more sophisticated control

functions may be realized, e.g., calculation of nonmea-

surable variables, adaptation of controller parameters,

detection and diagnosis of faults and, in the case of fail-

ures, reconﬁguration to redundant components. Hence,

mechatronic systems are developing with adaptive or

even learning behavior, which can also be called intelli-

gent mechatronic systems.

The developments to date can be found in [19.2,

7–11]. An insight into general aspects are given ed-

itorially in journals [19.5, 6], conference proceedings

such as [19.12–17], journal articles by [19.18–21], and

books [19.22–27]. A summary of research projects at

the Darmstadt University of Technology can be found

in [19.28].

Electronics

Information

technology

System theory

Modeling

Automation-technology

Sofware

Artificial intelligence

Mechanical elements

Machines

Precision mechanics

Electrical elements

Micro electronics

Power electronics

Sensors

Actuators

Mecha-

tronics

Mechanics

electro-

mechanics

Design

construction

Separate components

Conventional procedure

a) Mechatronic procedureb)

Mechan.

system

Electronics

Design

construction

Mechatronic overall system

Mechan.

system

Electron.

system

Fig. 19.4a,b Interrelations during the design and construction of

mechatronic systems

19.2 Mechanical Systems and Mechatronic Developments

Mechanical systems can be applied to a large area

of mechanical engineering. According to their con-

struction, they can be subdivided into mechanical

components, machines, vehicles, precision mechanical

devices, and micromechanical components.

The design of mechanical products is inﬂuenced by

the interplay of energy, matter, and information. With

regard to the basic problem and its solution, frequently

either the energy, matter or information ﬂow is dom-

inant. Therefore, one main ﬂow and at least one side

ﬂow can be distinguished [19.29].

In the following some examples of mechatronic

developments are given. The area of mechanical com-

ponents, machines, and vehicles is covered by Fig.19.5.

19.2.1 Machine Elements, Mechanical

Components

Machine elements are usually purely mechanical. Fig-

ure 19.5 shows some examples. Properties that can be

improved by electronics are, for example, self-adaptive

stiffness and damping, self-adaptive free motion or

pretension, automatic operating functions such as cou-

pling or gear shifting, and supervisory functions.

Some examples of mechatronic approaches are hy-

drobearings for combustion engines with electronic

control of damping, magnetic bearings with posi-

tion control [19.30], automatic electronic–hydraulic

gears [19.31], and adaptive shock absorbers for wheel

suspensions [19.32].

19.2.2 Electrical Drives and Servo Systems

Electrical drives with direct-current, universal, asyn-

chronous, and synchronous motors have used inte-

gration with gears, speed sensors or position sensors

and power electronics for many years. Especially the

development of transistor-based voltage supplies and

cheaper power electronics on the basis of transistors

and thyristors with variable-frequency three-phase cur-

Part C 19.2

320 Part C Automation Design: Theory, Elements, and Methods

Mechatronic systems

Mechatronic

machine

components

• Semi-active

hydraulic

dampers

• Automatic gears

• Magnetic

bearings

Mechatronic

motion

generators

• Integrated

electrical

servo drives

• Integrated

hydraulic

servo drives

• Integrated

pneumatic

servo drives

• Robots

(multi-axis,

mobile)

Mechatronic

power

producing

machines

• Brushless DC

motor

• Integrated AC

drives

• Mechatronic

combustion

engines

Mechatronic

power

consuming

machines

• Integrated

multi-axis

machine tools

• Integrated

hydraulic

pumps

Mechatronic

automobiles

• Anti-lock braking

systems (ABS)

• Electro hydraulic

break (EHB)

• Active suspension

• Active front

steering

Mechatronic

trains

• Tilting trains

• Active boogie

• Magnetic

levitated trains

(MAGLEV)

Fig. 19.5 Examples of mechatronic systems

rent supported speed control drives also for smaller

power. Herewith, a trend towards decentralized drives

with integrated electronics can be observed. The way

of integration or attachment depends, e.g., on space

requirement, cooling, contamination, vibrations, and

accessibility for maintenance. Electrical servo drives re-

quire special designs for positioning.

Hydraulic and pneumatic servo drives for linear

and rotatory positioning show increasingly integrated

sensors and control electronics. Motivationsare require-

ments for easy-to-assemble drives, small space, fast

change, and increased functions [19.33].

Multiaxis robots and mobile robots show mecha-

tronic properties from the beginning of their design.

19.2.3 Power-Generating Machines

Machines show an especially broad variability. Power-

producing machinesare characterized by the conversion

of hydraulic, thermodynamic or electrical energy and

delivery of power. Power-consuming machines convert

mechanical energy to another form, thereby absorbing

energy. Vehicles transfer mechanical energy into move-

ment, thereby consuming power.

Examples of mechatronic electrical power-genera-

ting machines are brushless DC motors with electronic

commutation or speed-controlled asynchronous and

synchronous motors with variable-frequency power

converters.

Combustion engines increasingly contain mecha-

tronic components, especially in the area of actuators.

Gasoline engines showed, for example, the following

steps of development: microelectronic-controlled injec-

tion and ignition(1979), electricalthrottle (1991), direct

injection with electromechanical (1999) and piezo-

electric injection valves (2003), variable valve control

(2004); see, for example, [19.34].

Diesel engines ﬁrst had mechanical injection pumps

(1927), then analog-electronic-controlled axial pis-

ton pumps (1986), and digital-electronic-controlled

high-pressure pumps, since 1997 with common-rail sys-

tems [19.35]. Further developments are the exhaust

turbochargers with wastegate or controllable vanes

(variable turbine geometry, VTG), since about 1993.

19.2.4 Power-Consuming Machines

Examples of mechatronic power-consuming machines

are multiaxis machine tools with trajectory control,

force control, tools with integrated sensors, and robot

transport of the products; see, e.g., [19.36]. In ad-

dition to these machine tools with open kinematic

chains between basic frame and tools and linear

or rotatory axes with one degree of freedom, ma-

chines with parallel kinematics will be developed.

Machine tools show a tendency towards magnetic

bearings if ball bearings cannot be applied for high

speeds, e.g., for high-speed milling of aluminum, and

Part C 19.2

Mechatronic Systems – A Short Introduction 19.3 Functions of Mechatronic Systems 321

also for ultracentrifuges [19.37]. Within the area of

manufacturing, many machinery, sorting, and trans-

portation devices are characterized by integration

with electronics, but as yet they are mostly not

fully hardware-integrated. For hydraulic piston pumps

the control electronics is now attached to the cas-

ing [19.33]. Further examples are packing machines

with decentralized drives and trajectory control or

offset-printing machines with replacement of the me-

chanical synchronization axis through decentralized

drives with digital electronic synchronization and high

precision.

19.2.5 Vehicles

Many mechatronic components have been introduced,

especially in the area of vehicles, or are in development:

antilock braking control (ABS) [19.38], controllable

shock absorbers [19.39], controlled adaptive suspen-

sions [19.40], active suspensions [19.41, 42], drive

dynamic control through individual braking (electronic

stability program, ESP) [19.43, 44], electrohydraulic

brakes (2001), and active front steering (AFS) (2003).

Of the innovations for vehicles 80–90% are based on

electronic/mechatronic developments. Here, the value

of electronics/electrics of vehicles increases to about

30% or more.

19.2.6 Trains

Trains with steam, diesel or electrical locomotives have

followed a very long development. For wagons the de-

sign with two boogies with two axes are standard. ABS

braking control can be seen as the ﬁrst mechatronic in-

ﬂuence in this area [19.45, 46]. The high-speed trains

(TGV, ICE) contain modern asynchronous motors with

power electronic control. The trolleys are supplied with

electronic forceand position control. Tilting trains show

a mechatronic design (1997) and actively damped and

steerable boogies also [19.47]. Further, magnetically

levitated trains are based on mechatronic construction;

see, e.g., [19.47].

19.3 Functions of Mechatronic Systems

Mechatronic systems enable, after the integration of the

components, many improved and also new functions.

This will be discussed by using examples.

19.3.1 Basic Mechanical Design

The basic mechanical construction ﬁrsthas tosatisfy the

task of transferring the mechanical energy ﬂow (force,

torque) to generate motions or special movements, etc.

Knowntraditional methods are applied, such as material

selection, calculation of strengths, manufacturing, pro-

duction costs, etc. By attaching sensors, actuators, and

mechanical controllers, in earlier times, simple control

functions were realized, e.g., the ﬂy-ball governor. Then

gradually pneumatic, hydraulic, and electrical analog

controllers were introduced. After the advent of digital

control systems, especially with the development of mi-

croprocessors around 1975, the information processing

part could be designed to be much more sophisticated.

These digitally controlled systems were ﬁrst added to

the basic mechanical construction and were limited

by the properties of the sensors, actuators, and elec-

tronics, i.e., they frequently did not satisfy reliability

and lifetime requirements under rough environmen-

tal conditions (temperature, vibrations, contamination)

and had a relatively large space requirement and cable

connections, and low computational speed. However,

many of these initial drawbacks were removed with

time, and since about 1980 electronic hardware has be-

come greatly miniaturized, robust, and powerful, and

has been connected by ﬁeld bus systems. Based on this,

the emphasis on the electronic side could be increased

and the mechanical construction could be designed as

a mechanical–electronic system from the very begin-

ning. The aim was to result in more autonomy, for

example, by decentralized control, ﬁeld bus connec-

tions, plug-and-play approaches, and distributed energy

supply, such that self-contained units emerge.

19.3.2 Distribution of Mechanical

and Electronic Functions

In the design of mechatronic systems, interplay for the

realization of functions in the mechanical and elec-

tronic parts is crucial. Compared with pure mechanical

realizations, the use of ampliﬁers and actuators with

electrical auxiliary energy has already led to con-

siderable simpliﬁcations, as can be seen in watches,

electronic typewriters, and cameras. A further consid-

erable simpliﬁcation in the mechanics resulted from

Part C 19.3

322 Part C Automation Design: Theory, Elements, and Methods

the introduction of microcomputers in connection with

decentralized electrical drives, e.g., for electronic type-

writers, sewing machines, multiaxis handling systems,

and automatic gears.

The design of lightweight constructions leads to

elastic systems that are weakly damped through the

material itself. Electronic damping through position,

speed or vibration sensors and electronic feedback

can be realized with the additional advantage of ad-

justable damping through algorithms. Examples are

elastic drive trains of vehicles with damping algorithms

in the engine electronics, elastic robots, hydraulic sys-

tems, far-reaching cranes, and space constructions (e.g.,

with ﬂywheels).

The addition of closed-loop control, e.g., for po-

sition, speed or force, does not only result in precise

tracking of reference variables, but also an approxi-

mate linear overall behavior, even though mechanical

systems may show nonlinear behavior. By omitting the

constraint of linearization on the mechanical side, the

effort for construction and manufacturing may be re-

duced. Examples are simple mechanical pneumatic and

electromechanical actuators and ﬂow valves with elec-

tronic control.

With the aid of freely programmable reference

variable generation, the adaptation of nonlinear me-

chanical systems to the operator can be improved.

This is already used for driving-pedal characteristics

within engine electronics for automobiles, telemanipu-

lation of vehicles and aircraft, and in the development

of hydraulically actuated excavators and electric power

steering.

However, with increasing number of sensors, ac-

tuators, switches, and control units, the cables and

electrical connections also increase, such that reliabil-

ity, cost, weight, and required space are major concerns.

Therefore, the development of suitable bus systems,

plug systems, andfault-tolerant and reconﬁgurableelec-

tronic systems are challenges for the designer.

19.3.3 Operating Properties

By applying active feedback control, the precision of,

e.g., a position is reached by comparison of a pro-

grammed reference variable with a measured control

variable and not only through the high mechanical pre-

cision ofa passivelyfeedforward-controlled mechanical

element. Therefore, the mechanical precision in design

and manufacturing may be reduced somewhat and sim-

pler constructions for bearings orslidewayscan be used.

An important aspect in this regard is compensation

of larger and time-variant friction by adaptive friction

compensation. Larger friction at the cost of backlash

may also be intended (e.g., gears with pretension), be-

cause it is usually easier to compensate for friction

than for backlash. Model-based and adaptive control

allow operation at more operating points (wide-range

operation) compared with ﬁxed control with unsatis-

factory performance (danger of instability or sluggish

behavior). A combination of robust and adaptive con-

trol enables wide-range operation, e.g., for ﬂow, force,

and speed control, and for processes involving engines,

vehicles, and aircraft. Better control performance al-

lows the reference variables to be moved closer to

constraints with improved efﬁciencies and yields (e.g.,

higher temperatures, pressures for combustion engines

and turbines, compressors at stalling limits, and higher

tensions and higher speed for paper machines and steel

mills).

19.3.4 New Functions

Mechatronic systems also enable functions that could

not be performed without digital electronics. Firstly,

nonmeasurable quantities can be calculated on the

basis of measured signals and inﬂuenced by feedfor-

ward or feedback control. Examples are time-dependent

variables such as the slip for tires, internal tensions,

temperatures, the slip angle and ground speed for steer-

ing control of vehicles or parameters such as damping

and stiffness coefﬁcients, and resistances. The auto-

matic adaptation of parameters, such as damping and

stiffness for oscillating systems based on measurements

of displacements or accelerations, is another example.

Integrated supervision and fault diagnosis becomes in-

creasingly important with more automatic functions,

increasing complexity, and higher demands on relia-

bility and safety. Then, fault tolerance by triggering

of redundant components and system reconﬁguration,

maintenance on request, and any kind of teleservice

makes the system more intelligent.

19.3.5 Other Developments

Mechatronic systems frequently allow ﬂexible adapta-

tion to boundary conditions. A part of the functions

and also precision becomes programmable and rapidly

changeable. Advanced simulations enable the reduction

of experimental investigations with many parameter

variations. Also, shorter time to market is possible if

the basic elements are developed in parallel and the

functional integration results from the software.

Part C 19.3

Mechatronic Systems – A Short Introduction 19.4 Integration Forms of Processes with Electronics 323

Table 19.1 Some properties of conventional and mechatronic designed systems

Conventional design Mechatronic design

Added components Integration of components (hardware)

Bulky Compact

Complex Simple mechanisms

Cable problems Bus or wireless communication

Connected components Autonomous units

Simple control Integration by information processing (software)

Stiff construction Elastic construction with damping by electronic feedback

Feedforward control, linear (analog) control Programmable feedback (nonlinear) digital control

Precision through narrow tolerances Precision through measurement and feedback control

Nonmeasurable quantities change arbitrarily Control of nonmeasurable estimated quantities

Simple monitoring Supervision with fault diagnosis

Fixed abilities Adaptive and learning abilities

A far-reaching integration of the process and the

electronics is much easier if the customer obtains the

functioning system from one manufacturer. Usually,

this is the manufacturer of the machine, the device or

the apparatus. Although these manufacturers have to in-

vest a lot of effort in coping with the electronics and

the information processing, they gain the chance to add

to the value of the product. For small devices and ma-

chines with large production numbers, this is obvious.

In the case of larger machines and apparatus, the pro-

cess and its automation frequently comes from different

manufacturers. Then, special effort isneeded to produce

integrated solutions.

Table 19.1 summarizes some properties of mecha-

tronic systems compared with conventional electrome-

chanical systems.

19.4 Integration Forms of Processes with Electronics

Figure 19.6a shows a general scheme of a classical

mechanical–electronic system. Such systems resulted

from adding available sensors and actuators and ana-

log or digital controllers to the mechanical components.

The limits of this approach were the lack of suit-

able sensors and actuators, unsatisfactory lifetime under

rough operating conditions (acceleration, temperature,

and contamination), large space requirements, the re-

quired cables, and relatively slow data processing.

With increasing improvements in the miniaturization,

robustness, and computing power of microelectronic

components, one can now try to place more emphasis on

the electronic side and design the mechanical part from

the beginning with a view to a mechatronic overall sys-

tem. Then, more autonomous systems can be envisaged,

e.g., in the form of encapsulated units with noncon-

tacting signal transfer or bus connections and robust

microelectronics.

Integration within a mechatronic system can be per-

formed mainly in two ways: through the integration

of components and through integration by information

processing (see also Table 19.1).

The integration of components (hardware integra-

tion) results from designing the mechatronic system as

an overall system and embedding the sensors, actua-

tors, and microcomputers into the mechanical process

(Fig.19.6b). This spatial integration may be limited to

the process and sensor or the process and actuator.

The microcomputers can be integrated with the actu-

ator, the process or sensor, or be arranged at several

places. Integrated sensors and microcomputers lead to

smart sensors, and integrated actuators and microcom-

puters develop into smart actuators. For larger systems,

bus connections will replace the many cables. Hence,

there are several possibilities for building an integrated

overall system by proper integration of the hardware.

Integration by information processing (software

integration) is mostly based on advanced control func-

tions. Besides basic feedforward and feedback control,

an additional inﬂuence may take place through pro-

cess knowledge and corresponding online information

processing (Fig.19.6c). This means processing of avail-

able signals at higher levels, as will be discussed in

the next Section. This includes the solution of tasks

Part C 19.4

324 Part C Automation Design: Theory, Elements, and Methods

Micro-

computer

Actuators Process Sensors

Micro-

computer

Actuators Process Sensors

Possible points of integration

Micro-

computer

Actuators Process Sensors

Process

knowledge

Hardware

Software

Information

processing

Fig. 19.6a–c Integration of mechatronic systems: (a) general

scheme of a (classical) mechanical–electronic system;

(b) inte-

gration through components (hardware integration);

through functions (software integration)

such as supervision with fault diagnosis, optimization,

and general process management. The corresponding

problem solutions result in online information process-

ing, especially using real-time algorithms, which must

be adapted to the properties of the mechanical pro-

cess, e.g., expressed by mathematical models in the

Control

feedback

Super-

vision

Information processing

Process

Manage-

ment

Higher

levels

Super-

vision

level

Control

level

Process-

level

Feedforw.

control

Methematical

process models

Information

gaining

• Identification

• State observer

Performance

criteria

Design methods

• Control

• Supervision

• Optimization

Feedword,

feedback

control

Supervision

diagnosis

Adaptation

optimization

Integration of components

Integration by information processing

Online information processing

Knowledge base

Micro-

computer

Actuator Process Sensors

Fig. 19.7 Integration of mechatronic systems: integration

of components (hardware integration); integration by in-

formation processing (software integration)

form of static characteristics, differential equations, etc.

(Fig.19.7). Therefore, a knowledge base is required,

comprising methods for design and information gain,

process models, and performance criteria. In this way,

the mechanical parts are governed in various ways

through higher-level information processing with in-

telligent properties, possibly including learning, thus

resulting in integration with process-adapted software.

Both types of integration are summarized in Fig. 19.7.

In the following, mainly integration through informa-

tion processing will be considered.

Recent approaches for mechatronic systems mostly

use signal processing at lower levels, e.g., damp-

ing or control of motions or simple supervision.

Digital information processing, however, allows the

solutions of many more tasks, such as adaptive con-

trol, learning control, supervision with fault diagnosis,

decisions for maintenance or even fault-tolerance ac-

tions, economic optimization, and coordination. These

Fig. 19.8 Different levels of information processing for

process automation. u: manipulated variables; y: measured

variables; v: input variables; r: reference variables

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Part C 19.4