17291342-mechatronics

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Introduction

The word mechatronics was first introduced by the

senior engineer of a Japanese company; Yaskawa,in 1969, as a combination of"mecha" o

mechanisms and "tronics" of electronics, and the

company was granted trademark rights on the

word in 1971.


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Mechatronics is synergistic integration of mechanical

engineering, electronics and intelligent computer control in

design and manufacture of products and processes.

Mechatronics - Definition


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Evolution of Mechtronic SystemsThe development of mechatronics has gone through threestages.

The first stage corresponds to the years when this termwas introduced. During this stage, technologies used inmechatronic systems developed rather independently and

individually.

During the second stage, i.e., with the beginning of theeighties, a synergistic integration of different technologiesstarted taking place, the no-table example isoptoelectronics (i.e. an integration of optics andelectronics). The concept of hardware/software co-designalso started in those years.


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The third and the last stage can also be considered as the

beginning of the mechatronics age since early nineties.

The most notable aspect of the third stage is the increased

use of computational intelligence in mechatronic products

and systems. It is due to this development that we can now

talk about 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).


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Key elements of Mechatronic System


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Actuators

Most mechatronic systems involve motion oraction of some sort.

Actuators are the devices used to producethis motion or action.

This motion or action can be applied to anything from a single atom to a large

articulated structure.It is created by a force or torque that resultsin acceleration and displacement.


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Actuators produce physical changes such as linearand angular displacement.

They also modulate the rate and power associatedwith these changes.

An important aspect of mechatronic system designis selecting the appropriate type of actuator.

Types of actuation systemsPneumatic and hydraulic actuation systems

Mechanical actuation systems

Electrical actuation systems


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Sensors

A sensoris an element in a mechtronic or

measurement system that acquires a

physical parameter and changes it into asignal that can be processed by the system.

Often the active element of a sensor is

referred to as a transducer.


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Transducers are grouped according to what they arebeing used to measure

Displacement position and proximity

Velocity and motion sensors

Force

Fluid pressure

Liquid flow

Liquid level

Temperature

Light sensors


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Necessity for Input Signal Conditioning

The transducers which converts physical quantitieslike temperature, displacement etc., into currentsor voltages and gives them in the form of analogsignals, which are continuous and time varying.

Often the signal from the traducers may be

Too small (in milli volts)

Too noisy (due to electromagnetic interference)

Containing wrong information (due to poortransducer design)

Having DC offset (due to transducer and

instrumentation design)


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Many of these these problems can be

remedied and the desired signal information

can be extracted through appropriate analogsignal processing.

The simplest and the most common form osignal processing is amplification, where

the magnitude of the signal is increased.


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Need for digital signal

Analog signal are continuous and time

varying, whereas digital signals have only

two stages: high and low.Since computers and microprocessors

require digital signals, any application

involving computer measurement orcontrol requires analog to digital

conversion.


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Control Architectures

To obtain completeness in the integration of

mechanical devices

sensorssignal and

power electronics

into the most advanced mechatronic systems,microprocessorbased control systems must be

included.


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Hierarchy of basic control approaches

Analog circuits

Digital Circuits

PLCs

Microcontroller

Single Board Computer

Personal Computer.


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Copy Machine A typical example of a

Mechatronic System

An office copy machine consists of analog anddigital circuits, sensors, actuators andmicroprocessors.

Analog circuits control the lamp, heater and otherpower circuits in the machine.

Digital circuits controls the digital displays,indicator lights, buttons and switches forming theuser interface.


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Optical sensors and micro switches detects thepresence or absence of the paper, its proper

positioning and whether or not doors and latchesare in their correct positions.

Other sensors include encoders used to track the

motor rotation.

Actuators include servo and stepper motors that

load and transport the paper, turn the drum andindex the sorter.

Microprocessors coordinate all the functions in the

machine


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Examples of Mechatronic Systems (MS)

computer diskdrive

clothes washer


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DESIGN

OFMECHATRONIC

SYSTEMS


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STAGES IN DESIGN PROCESS

The need

Analysis of problem

Preparation of Specification

Generation of possible solutions

Selection of a suitable solution

Production of a detailed design

Production of working drawings


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TRADITIONAL DESIGN VS MECHATRONICS DESIGN

TRADITIONAL DESIGN

:The temperature control for a domestic

central heating system has been the bi-metallic thermostatof a closedloop control system. The bending of bi-metallic strip changes as thetemperature changes and is used to operate an on/off switch for theheating system.

The bi-metallic thermostat is comparatively crude and the temperature

is not accurately controlled; also devising a method for having differenttemperatures at different times of the day is complex and not easily

achieved.

MECHATRONIC DESIGN: A mechatronic solution to the problemmight be to use a microprocessor controlled system employing perhaps

a thermo-diode as the sensor

The microprocessor-controlled system can, however, cope easily withgiving precision and programmed control. The system is much moreflexible. This improvement in flexibility is a common characteristic ofmechotronics systems when compared with traditional systems.


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THERMOSTAT

TRADITIONAL DESIGN MECHATRONICS DESIGN


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TRADITIONAL THERMOSTAT DESIGN

SECTIONAL VIEW COMPONENTS OF THERMOSTAT


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CONVERSION TO MECHATRONIC DESIGN


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ADVANTAGES OF MECHATRONICS DESIGN

HIGH RESOLUTION & ACCURACY

REDUCES HOUSE HOLD HEATING COST

SELF CALIBRATING

FLEXIBLE DESIGN

ENVIRONMENTAL FRIENDLY


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TINY MCUs IN SWITCHES & POTENTIOMETERS


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MECHATRONIC SYSTEMS

CASE STUDIES


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TIMED SWITCH

Consider a simple requirement for a device whichswitches on some actuator, e.g. a motor, for someprescribed time.

A mechanical solution could involve a rotating camThecam would be rotated at a constant rate and the camfollower used to actuate a switch, the length of time forwhich the switch is closed depends on the shape of cam.


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MECHATRONICS SOLUTION

A PLC arrangement could involve

the arrangement shown in figure

with the given ladder program. This

would have the advantage over the

rotating cam of having off and ontimes which can be adjusted by

purely changing the timer preset

values in the program where as

different cam is needed if the times

have to be changed with the

mechanical solution.


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A microprocessor-based solution could involve a microprocessor witha memory chip and input/output interfaces. The program is then usedto switch an output on and off after some time delay with the timedelay being produced by a block of program in which there is a timingloop. This generates a time delay by branching round a loop the

number of cycles required to generate the requisite time, inassembly language:

DELAY LDX

LOOP DEX

BNE LOOP

RTS

o DEX decrements the index register, and this and BNE, branch if notequal, each take 4 clock cycles. The loop thus takes 8 cyclthere will be n such loops until 8n+3+5 gives the number F424 (LDXtakes 3 cycles and RTS takes 5 cycles). In C we would write theprogram lines using the while function.


A lt ti t i l i t


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An alternative to using a loop is to use atimer module, e.g. 555, with themicroprocessor.

With the 555 timer the timing intervalsare set by external resistors andcapacitors.

Figure shows the timer and the externalcircuitry needed to give an on-outputwhen triggered, the duration of theon-output being 1.1RC.

Large times need large values of R andC. R is limited to about 1 Mc otherwiseleakage becomes a problem, and C islimited to about 10 F if electrolyticcapacitors with problems of leakage andlow accuracy are to be avoided. Thus the

circuit shown is limited to times less thanabout 10 s. the lower limit is about R= 1kc and C= 100pF, i.e. times of a fractionof a millisecond. For longer times, from16 ms to days, an alternative timer suchas the ZN1034E can be used.

555 timer

(a) Generating 2 MHz internal clock


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Another possibility is to use the timer system in amicrocontroller such as MC68HC11.

The timer system is based on a 16-bit counter TCNToperating from the system E-clock signal (Figure (a)).

The system E-clock can be pre-scaled by setting bits in thetimer interrupt mask register 2 (TMSK 2), address $1024(Figure (b)).

The TCNT register starts at $0000 when the processor is resetand counts continuously until it reaches the maximum countof $FFFF.

On the next pulse it overflows and reads $0000 again. When itoverflows it sets the timer overflow flag TOF (bit 7 inmiscellaneous timer interrupt flag register 2, TFLG2 ataddress $1025).

Thus with a pre-scale factor of 1 and an E-clock frequency of2 MHz, over flow occurs after 32.768

One way of using this for timing is for the TOF flag to bewatched by polling. When the flag is set, the programincrements its counter. The program then resets the flag, bywriting a 1 to bit 7 in the TFLG2 register. Thus the timingoperation just consists of the program waiting for therequired number of overflag settings.

(a) Generating 2 MHz internal clock

(b) Pre-scaled factor


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A better way of timing involves the use of the output-compare function.

Port A of the microcontroller can be used for generalinputs or outputs or timing functions.

The timer has output pins, OC1,OC2,OC3,OC4 and OC5,with internal registers TOC1, TOC2, TOC3, TOC4 andTOC5.

We can use the output-compare function to compare thevalues in the TOC1 to TOC5 registers with value in thefree running counter TCNT. This counter starts at 0000

when the CPU is reset and then runs continuously.

When a match occurs between register and the counterthen the corresponding OCx flag bit is set and outputoccurs through the relevant output pin.

The Figure shown illustrates this. Thus by programming

the TOCx register, so the times at which output occur canbe set. The output-compare function can generate timingdelays with much higher accuracy than the timeroverflag.

OUTPUT COMPARE


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An alternative solution is to use a

stepper motor.

Figure below shows how a

microprocessor with a PIA, or a

microcontroller, might be used

with a stepper.

The input to the stepper is

required to cause it to rotate a

number of steps in one direction

and then reverse to rotate the

same number of steps in one

direction and then reverse to

rotate the same number of steps

in the other direction.

If h i b i h f ll fi i h h d b h i


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If the stepper is to be in the full-step configuration then the outputs need to be as shown inTable below. Thus to start and rotate the motor in a forward direction involves the sequenceA, 9, 5, 6 and then back to the beginning with 1 again. To reverse we would use the sequence6, 5, 9, A and then back to begin with 6 again.

1 1 0

2 1 0

3 0 1

4 0 1

1 1 0

Step Bit 3 Bit 2

If half-step configuration is used then the outputs need to be asIf half-step configuration is used then the outputs need to be as

shown in Table below.shown in Table below.

1 1 0

2 1 0 3 1 0

4 0 0

5 0 1

6 0 1

7 0 1

8 0 0

1 1 0

Step Bit 3 Bit 2 B


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Where there are many steps involved a simpler program is to increment acounter with each step and loop until the counter value reaches the requirednumber. Such program would have the basic form of:

Advance a step

Jump to time delay routine to give time for the step to be completed.

Increment the counter.

Loop or repeat the above with successive steps until the counter indicates therequisite number of steps completed in the forward direction.

Reverse direction

Repeat the above for the same number of steps in reverse directi


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Integrated circuit SAA 1027 for stepper motor

Integrated circuits are available for stepmotor control and their use can simplifythe interfacing and the software.

Figure shows how such a circuit can beused.

All that is then needed is the requisite

number of input pulses to the trigger, themotor stepping on the low-to-hightransition of a high-low-high pulse.

A high on the rotation input causes themotor to step counter-clockwise while alow gives clockwise rotation.

Thus we just need one output from themicrocontroller for output pulses to thetrigger and one output to rotation. Anoutput to set is used to reset the motorback to its original position.

BATHROOM SCALES or


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SIMPLE WEIGHING MACHINE

The main requirements are that a person canstand on a platform and the weight of that person

will be displayed on some form of readout. Theweight should be given with reasonable speed andaccuracy and be independent of where on theplatform the person stands.

One possible solution is to use the weight of theperson on the platform to deflect an arrangement

of two parallel leaf springs (Figure (a)). With suchan arrangement the deflection is virtuallyindependent of where on the platform the personstands.

The deflection can be transformed into movementof a pointer across a scale by using the

arrangement shown in Figure (b). A rack-and-pinion is used to transform the linear motion into acircular motion about a horizontal axis. This isthen transformed into a rotation about a verticalaxis, and hence movement of a pointer across ascale, by means of a bevel gear.



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It involves the use of a microprocessor.

The platform can be mounted on load cells

employing electrical resistance strain gauges.When the person stands on the platform thegauges suffer strain and change resistance.

If the gauges are mounted in a four-active-arm Wheatstone bridge then the out-of-balance voltage output from the bridge is ameasure of the weight of the person.

This can be amplified by a differentialoperational amplifier. The resulting analogsignal can then be fed through a latchedanalog-to-digital converter for inputting tothe microprocessor, e.g. the Motorola 6820.

The adjacent Figure shows the inputinterface. There will also be a need to providea non-erasable memory and this can beprovided by an EPROM chip, e.g. Motorola2716. The output to the display can then betaken through a PIA, e.g. Motorola 6821.


If i t ll i d th i t ithi th i l


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If a microcontroller is used then memory is present within the singlemicroprocessor chip, and by a suitable choice if a microcontroller, e.g. M68HC11,the analog-to-digital conversion can be obtained for the inputs.

The system then becomes: strain gauges feeding through an operational amplifiera voltage to the port E (the ADC input) of the microcontroller, with the output

passing through suitable drives to output through ports B and C to a decoder andhence a LED display (Figure below).

A PICK AND PLACE ROBOT


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A PICK-AND-PLACE ROBOT

The basic form of a Pick-and-Place robot unit is shown inthe Figure (a).

The robot has three axes, about which the motion can occuri.e. rotation in a clockwise or counter clockwise direction ofthe unit on its base, arm extension or contraction and armup and down; also the gripper can open and close.

These movements can be actuated by the use of pneumaticcylinders operated by solenoid-controlled valves with limitswitches to indicate when a motion is completed.

Thus the clockwise rotation of the unit might result fromthe piston in a linear cylinder being extended and thecounter clockwise direction by its retraction. Likewise theupward movement of the arm might result from the pistonin a linear cylinder being extended and the downwardmotion from it retracting; the extension of the arm by thepiston in another cylinder extending and its returnmovement by the piston retracting.

The gripper can be opened or closed by the piston in alinear cylinder extending or retracting. Figure (b) shows abasic mechanism that could be used

Figure (a)

Figure (b)



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Figure below shows how a micro controller could be used to control the

solenoid valves and hence the movements of the robot unit.



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CAR PARK BARRIERSAs an illustration of a PLC, consider the coin-operated barriers for a car park.

The in-barrier is to open when the correctmoney is inserted in the collection box and theout-barrier is to open when a car is detected atthe car park side of the barrier.

The Figure shows the types of valve systems thatcan be used to lift and lower the pivotedbarriers.

When a current flows through the solenoid ofvalve A, the piston in a cylinder moves upwardsand causes the barrier to rotate about its pivotand raise to a let a car through. When thecurrent through solenoid of valve A ceases, thereturn spring of the valve results in the valve

position changing back to its original position.

When the current is switched to through thesolenoid of valve B the pressure is applied tolower the barrier. Limit switches are used todetect when the barrier is down and also whenfully up.

C A O CS SO O


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PLC connections Ladder diagram


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AUTOMATIC CAMERAThe basic features of the Canon EOS model, automatic, auto-focus,reflex cameras is shown in the Figure (a) .

The cameras have interchangeable lenses.

There is a main microcontroller in the lens housing, the twocommunicating with each other when a lens is attached to the camerabody.


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BLOCK DIAGRAM OF THE ELECTRONIC SYSTEM


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The metering sensor has six light sensors asshown in the Figure.

Signal conditioning is used to obtain theaverage value of C1, C2, C3, and C4; the A, Band average C value are then analysed to findthe required exposure value. This, forexample, reveals whether the scene is a scenewith a relatively constant luminosity orperhaps a close up of a person so that there isbright central zone surrounded by a darkbackground.

The type of program that is used is:

If B is equal to A and C minus B is

less than 0

then exposure set on value of A

if B is equal to A and C minus B is 0

then exposure set on value of C


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For the main microcontroller

Send start command to lens microcontroller

Take input from range sensor

Calculate lens movement required

Send lens movement data to lens microcontroller

Wait for verification of lens movement from microcontroller

Send in-focus signal to viewfinder display

For the lens microcontroller

Wait for start command from main microcontroller

Determine the initial lens position

Wait for lens movement data from main microcontroller

Read lens movement dataCalculate new lens position

While lens is not in new position drive the motor

Send verification signal of in-focus to main microcontroller

This information is translated by thei t ll i t i t h tt


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microcontroller into an appropriate shutterspeed and aperture value. If the camera isoperated with the shutter speed preselectedby the photographer then only the aperturevalue is supplied; similarly if the aperture ispreselected then only the shutter speed is

supplied.

The range sensor has two 48-bit lineararrays of photo detectors. The light fromthe object, after passing through the cameralens, falls on this array (Figure). When theimage is in focus the spacing of the images

on the detector array is a particular value,the spacing deviating from this when theimage is out of focus.

The amount of this deviation is used to givean error signal, which is fed to the lens

microcontroller and used to give an outputto adjust the focusing of the lens. Anencoder is used to provide feed back of thisadjustment so that the microcontrollerknows when the focusing has beencompleted. The program is thus of theform: Automatic focusing

The diaphragm drive system is a stepper motor,


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The diaphragm drive system is a stepper motor,which opens or closes a set of diaphragm blades.

The focusing involves two forms of drive, the arcform drive and the ultrasonic motor. The arc formdrive uses a brushless permanent magnet

d.c.motor, Hall sensors being used to detect theposition of the rotor.

The drive from the motor is transmitted throughgears to move the focusing lens along the opticalaxis. The ultrasonic motor has a series opiezoelectric elements in the form of a ring (Figure

(a). When a current is supplied to the piezoelectricelement it expands or contracts according to thepolarity of the current.

By switching the current to the piezoelectricelements in the appropriate sequence adisplacement wave can be made to travel aroundthe piezoelectric ring of elements in either aclockwise or counter-clockwise direction andconsequently rotate a rotor which is in contactwith its surface, hence driving the focusing element

The control system for the ultrasonic motor is othe form shown in Figure (b)


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CAR ENGINE MANAGEMENT

The modern car is likely to include manyelectronic control systems involving microcontrollers, the engine control system being

one.

Figure below shows a generalized block diagram of such a system its


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Figure below shows a generalized block diagram of such a system, itsaim being to ensure that the engine is operated at its optimum settings.

The system consists of sensors supplying, after suitable signal


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The system consists of sensors supplying, after suitable signal

conditioning, the input signals via drivers to actuate actuators. Figure

below shows some of these elements in relation to an engine; only one

cylinder is being shown.

BAR CODE ENCODER


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BAR CODE ENCODER

The familiar scene at the check-out of a supermarket is of the

purchases being passed in front of a light beam or a hand-held wand

being passed over the goods so that the bar code can be read and the

nature of the purchase and hence its price automatically determined.

The code consists of a series of black and white bars of varying widths.

Th b d t i f b


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The bar code represents a series of numbers.

There is a prefix which identifies the coding scheme being used; this is a singledigit for the regular Universal Product Coding (UPC) used in the United

States and two digit for the European Article Number (EAN) scheme used inEurope.

The UPC uses a 0 prefix for grocery and a 3 for pharmaceuticals. The EANprefix is from 00 to 09 and is such that the UPC code can be read within theEAN code.

This is followed by five digits to represent the manufacturer, eachmanufacturer having been assigned a unique number.

This brings up the center of the code pattern, which is identified by two tallerbar patterns.

The five-digit number that then follows represents the product. The finalnumber is a check digit, which is used to check that the code has beencorrectly read.

A guard pattern of two taller bars at the start and end of the bar pattern is usedto frame the bars.

Each number is coded as seven 0 or 1 digits.


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The codes used on either side of the centerline are different so that the direction of the scancan be determined.

To the right the characters have an even number of 1s and so even parity; for UPC, to the

left an odd number of 1s and so odd parity; the EAN coding for the left being a mixture.

Table below shows the UPC and EAN codings, UPC being the left A coding and the EANusing both left A and left B character codes.

0 0001101

1 0011001

2 0010011

3 0111101 4 0100011

5 0110001

6 0101111

7 0111011

8 0110111

9 0001011

Decimal number Left A

Characters Characters


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Each 1 is entered as a dark bar and

thus the right-hand character 2 would

be represented 1101100 and, with the

adjacent dark bars run together, it

appears as a double-width dark wide

bar followed by a narrow space and

then another double-width dark wide

bar followed by a double-width space.

This is illustrated in Figure below.

The guard pattern at the ends of the

code represents 101 and the central

band of bars is 01010.


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INVERTED PENDULUM SYSTEM: ROTARY


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INVERTED PENDULUM SYSTEM: ROTARY

AND ARM-DRIVEN

The inverted pendulum is a popular mechatronic application thatexists in many different forms. The common thread among these

systems is their goal:

to balance a link on end using feedback control.

Two rather challenging inverted pendulum systems are the

rotational and the arm-driven systems.

These use a link rotating about an axis to balance a second link on end.

In the rotary (horizontal) configuration, the first link, driven by a

motor, rotates in the horizontal plane to balance a pendulum link,

which rotates freely in the vertical plane. The arm-driven (vertical) orstick-on-a-stick configuration uses a driven link rotating in the

vertical plane to balance the pendulum link, which also rotates in the

vertical plane.

The inverted pendulum system is unique in that it can be transformed from


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The inverted pendulum system is unique in that it can be transformed from

the horizontal to vertical configuration by replacing the links and setting

the base on its side, as shown in Figure

Figure: Inverted Pendulum System Configurations: (a) Horizontal and (b) Vertical

(a) (b)

Rotary inverted pendulum dynamic system investigation:


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Physical System : It consists of two links: a motordriven

horizontal link and an un-actuated vertical pendulum link. The

horizontal link is driven by a permanent-magnet, brushed DC

motor. A DC power supply together with a pulse-width-

modulated (PWM) servo-amplifier, operating in the current

mode, supply power to the motor.

Angular position and velocity of the two links are measured

with two rotary incremental optical encoders having a

resolution with quadrature decoding of 2048 pulses per

revolution.

A slip ring assembly mounted between the housing and the


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A slip-ring assembly, mounted between the housing and the

motor shaft, is used to connect power to the pendulum

optical encoder and read the signal from the three channels

of the encoder. The horizontal link is counter-weighted andthere are leveling screws on the housing base. System

testing for parameter identification and control system

design is performed in a MatLab / Simulink / dSpace real-

time control environment. This allows for rapid control

system development and testing.

Physical Model

Several simplifying assumptions were made in developing aphysical model:

1. rigid links

2. two degrees of freedom

3. negligible sensor dynamics

Control System design: Balancing and swing-up


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The swing-up control is based on the work of Astrom and

Furuta and the balancing controller is a full state-feedback

regulator. The swing up controller calculates the totalsystem energy based on the kinetic energy of both links, and

the potential energy of the pendulum.

This calculated value is compared to a defined quantity o

energy when the pendulum is balanced. The difference

between desired energy and actual energy is multiplied by

an "aggressivity" gain and applied to the motor.


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Figure : MatLab/Simulink Block Diagram of Control System Design


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Figure : MatLab/Simulink Block Diagram of Control Selection Subsystem

The objective of the swing-up control exercise is to move the system from the

stable equilibrium position to the unstable equilibrium position. Hence, energy

has to be added to the system to achieve this swing-up action. The

manipulated input to realize the above idea is given by the following control

law:

V = KA (E EO) sign( cos )


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The velocity term causes the input

to change directions when the

pendulum stops and begins to swing

in the opposite direction. The cosineterm is negative when the pendulum

is below horizontal and positive

above horizontal. This helps the

driven link to get under the

pendulum and catch it as shown in

Figure below. By controlling on

energy feedback, the system

automatically stops inputting excess

energy and allows the system to

coast to a balanced position.

Figure : Sign function effect on swing up


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Figures below show the simulation results for the swing-up and balance


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Figures below show the simulation results for the swing up and balance

controllers. The angles plotted are normalized angles.

Figure : Normalized Pendulum angle Versus Time Figure : Normalized Driven Link angle Versus Time

DESIGN OF AN ATOMIC FORCE MICROSCOPE


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DESIGN OF AN ATOMIC FORCE MICROSCOPE

The atomic force microscope (AFM) is a mechatronic instrumentthathas had a revolutionary impact in the last decade on the ability to

image the topography of surfaces in the micron to subnanometerrange. AFMs form images of surface properties by scanning acantilevered probe with a sharp tip over the surface of a sample inan x-y raster pattern.


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The deflection of the probe caused by repulsive (or

attractive) forces between atoms of the tip and sample is

used to quantitatively map the topography or determine

other properties of the surface .

AFMs are used extensively by researchers across the

disciplines of physics, chemistry, biology, material science,

and others to image surface properties, measure

fundamental force interactions, and understand

mechanical properties of materials.

AFMs are also being used as metrology instruments

particularly in the semiconductor industry.


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The main subsystems that

comprise an AFM are:

the cantilever probe,

the scanner,

the deflection sensing system,

the controller,

the data acquisition

the processing system, and

the mechanical assembly

Figure : Schematic diagram of an atomic force microscope (AFM).

Figure (a) shows AFM


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Figure (a) shows AFM

cantilevers: shows typical

rectangular or triangular

shapes of cantilevers. Therectangular cantilever on the

left is 200-_m long and 20-_m wide.

Figure (b) and (c) shows a

close-up view of the tip of a

cantilever. AFM cantilevers

are made using IC

fabrication and silicon

micromachining processes

Figure : Cantilever deflectiont h


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measurement approaches:

(a) shows the optical leverapproach, where deflection of the

cantilever causes the reflectedlaser beam to illuminate onephotodetector cell more than theother. The motion of the beam,hence the deflection of thecantilever, can be quantified by

taking the difference of thephotocurrents from the two cellsand

(b) shows the piezoresistivecantilever approach, where a

specially fabricated cantilever isconnected as one leg of aWheatstone bridge. Thedeflection of the cantilever issensed by a change in the outputvoltage of the bridge.

Mechatronic Design of the Hewlett-Packard DESKJET


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Mechatronic Design of the Hewlett-Packard DESKJET

560C Printer

The mechatronic related design objectives for this

printer are shown in Table below.

MECHATRONIC DESIGN


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Figure illustrates the

mechatronic design of theprinter.

The printer uses three motors:

a dc motor drives the scanningcarriage, one permanentmagnet tin-camotor drives the paper feedsystem, and a second

permanent magnet steppermotor actuates the printcartridge service station.

MECHATRONIC DESIGN

Figure : HP deskjet Mechatronic System

All three of these motors are controlled with less than


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10% of the bandwidth of an inexpensive 8-bit Z-80

microprocessor

Figure : Control System Block Diagram


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Modern Trends of MS Development

Office equipment;Computer facilities;

Photo and video

equipment;

Machine-tool construction and

equipment for automation of

technological processes;

Robotics;


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Aviation,

space and military

techniques;

Motor car construction


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Simulators for training of

pilots and operators;

Show-industry;

Control and measuring

devices and machines;Micro machines;

Non-conventional vehicles.

F d t l P bl


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Fundamental Problems

Structural integration of mechanical, electronic andinformation departments into a uniform creative staff;

Education and training of engineers specialized inmechatronics and managers able to organize integration andsupervise work of strictly specialized experts with differentqualifications;

Integration of information technologies from variousscientific and technical fields into a uniform toolkit to providecomputer support of mechatronic problems;

Standardization and unification of all used elements andprocesses at designing and manufacturing MS.

Levels of Mechatronic Systems


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y

Integration

The First Level

conveyors,

rotary tables,

auxiliary manipulators

L l f M h t i S t


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Integration

The Second Level

operated power machines (turbines

and generators),

machine tools and industrial robots

with numerical program

management

L l f M h t i S t


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Integration

The Third LevelSynthesis of new precise information and

measuring high technologies gives a basis

for designing and producing intellectual

mechatronic modules and systems.


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17291342-mechatronics

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