Practice English Speaking&Listening with: Lecture - 22 Velocity Analysis

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Good Morning, This is Lecture No. 2 of the module futuristic topic on Robotics okay,

In this First lecture module .we studied micro Electrical systems from characteristics futuristic

topic and some technology what is name?

What it is important for and why it is gaining for?

Then some issues related to how the names based device from fabricated what are the

different fabrication fascination involved and then we had a little bit look at used

of names in robotics so in today' s class we will have some introduction on some other

unconventional names in fabrication method and their use .

In actually building the micro robots so we will have look at that and then there are

technologies where you do not have right now any applications in robotics.

But they very much potential for applications in robotics.

Okay, so these technologies will study first and then we will go on to applications in

robotics .with the technology which we have studied in the last lecture okay, So to the

base like silicon base Phillies.

Base names fabrication technologies that technology will apply some micro robots micro accelerators,

micro manipulators and we will see how this quizzes can be fabricated by using QDA fabrication

of dulcet base technologies okay So what we will study is basically is unconventional

fabrication possessives like micro studio lithography okay, I will explain you what

is this process.

And what are the important aspects of this process why it is different from your conventional

base or silicon base or dulce base fabrications and then the laser base micro motion it will

have a little bit look at this laser base micro motioning technologies okay Why it is

important again like what are this advantages in like that and then we will move on to name

space micro manipulator okay, Or application of this technologies or robotic purposes the

main important application most squarely used popular this days.

Micro manipulation okay, This micro manipulation is important for like?

Bio-cells who want to manipulate bio- cells who want to move and study their properties

the thing like that this is very important for bio applications and in bio surgery where

you want to manipulate very accurately very phsislely some location in your brain surgery

or whatever okay, In those application this micro manipulators are very important.

Okay, And then we will study one mobile micro robot this is very recent development and

but you will look at and see how like what is a domain in a micro domain how things are


From the conventional domain okay, So we will have look at that fine.

That would conclude this today's class this module will be futuristic of this robotics

okay, Then also we will have look at some other topics which are not covered in this

course but you should be aware of that they are some other topics related to futuristic

they are more futuristic kind of applications .okay, let us start with a micro schedule


What is the motivation for studying or for going this process micro schedule lithography

basically the limitations of the conventional names fabrications are like basically it has


a capability to fabricate only to dimensional micro components okay, Or plainer kind of

components you can have multiple plains?

But essentially they are plainer components you can have one level, two level, three level,

procedures for micro fabrications but they are essentially of plainer in nature okay.

So each level we will have a plainer structure okay, But you can have like multiple plain

but in many applications one may need through 3D through type of components okay, We just

doesn't have plainer laser but it is like two three dimensional nature like say for

example, You can imagine a flower pot.

Kind of a structure okay, It's a true 3D structure so how to fabricate those kind of components.

So that is a basic motivation for going for the micro studio schedule other important

motivations is basically limitation on the number of masteries that can be processed

conventional name professors okay.

Micro lithography gives like more number of masteries or more wider choices for masteries

we poses okay, You can poses hethamixe you he can poses metal powder or he can poses

polymers in micro lithography okay, Polymer and ceramic entering are very widely used

for micro lithography okay.

Now what is a idea how microstereolithography works okay, Is the idea base on the which

is rapid programming okay, So it is like you build a component there is a liquid and then

you use that liquid photopolymer it will get affected like these liquid will get affected.

Then the liquid will turn into soled when you expose it to layer okay,

So that is a photopolymer liquid okay, And then the idea is like to generate one plain

planar section on the surface of the liquid and then you have other planar section?

Built on the top of these planar section okay, So these section by section you gone building

the components okay.

So let us see how these process will look like in animation.

So but that is a basic process that you built components layer by layer.

So if you have say as for example follower pot example if you take you first dived the

soled starchier into plains Into different layers of plains okay.

And then you have each planar structure or each plain or each section build level by

level okay.

So first you will have a first lower level section build on the top of that next section

will be build like that you will gone building the components level by level or layer by

layer okay.

So there different types of this process first are a scanning type process.

In which you scan a section by lines okay.

So you will have plain in which you will have a different lines drawn okay.

I will show you again how the scanning process works.

But you don't exposes the entire layer at a time to light okay.

You will scene one line okay, by a laser which is pointing on the surface okay.

So then you scan on next line like that you can scan the different lines then gone building

the sections okay, That is a process we will come to that again in the animation.

I will explain you that but that is a scanning where there is no exposure entire of the entire

section at a time in the dynamic mass process.

We have a mass which its changing his step dynamatically or automatimatically so in this

process is like how it changes and all we will go in to little more detail in the slides

to come but it is basically you have a mass which his changing continuously okay, so you

exposes at a time in one section okay, then change a shape of a mass and exposes the next


so like that it is a process of building components there is exposure at a time for a entire section


Again I will come to that when I will explain you detail how this process actually works.

But these are the basics to differentiate like in the scanning type process and dynamic

mass process okay, Let us the scanning proceeds in more detailed.

Okay, what you see here his laser curable photopolymer liquid which is kept in this

tank and then there is a lens which is to focus the laser light on the surface of this

photopolymer you have this zee elevator which will move this stage in to the liquid once

the one of the section is completed to that next section can be build on the top of the

section okay and then you have these mirror actually.

I have shown your one mirror but it should be two mirrors you have to scan in the both

the direction, so I the sake of simplicity I have taken only one mirror.

But you will typically have a scanning system which is similar to then what you the monitor

have, But n this case the difference is like the deflection of the laser beam their happening

because of the movement of the mirror.So we will see what are the different type of movement

we can achieve that but essentially there is a mirror.

Which is moving and then it is scanning the particular section on the surface.

Now let us see how the scanning happens again the photo polymer and elevator the elevator

is first dipped in the photo polymer and then it is brought up.

So that the particular thickness of the liquid is there on the top of the surface that is

the elevator now you want to scan one of the section, sections say is this of the shape

and now you can see how the scanning is done line by line the entire section is provide,

so this elliptical shape you wanted here is drawn line by line so, you can obviously see

there are some errors that will occur will not be an exact section.

It will be slight error because of the error but, there will be their limit the accuracy

may be 5 to 10 percent okay if you are scanning like bigger sections okay then it be much

better if you are scanning very small sections then you will have a little bit lesser accuracy

in terms of percentage okay so I mean you can see a limitations again with these because

a these kind of effects will not be able to build very, very tiny sections.

I mean very tiny micro components which are of sub micro damages is not possible okay

so this is kind of technology is use to build components in the range about like say a 30

micron onwards or 20 micron onwards okay you cannot really I mean you can go below that

but then like it will be very costly process in the first place and then I mean it will

have that accuracy problem In terms of percentage accuracy okay.

So once you do this scanning the section will be built on the surface here okay so this

shows the top view and this is the section view of the okay so now once this section

is built again the process is repeated you dip again in to the liquid photo polymer so

that the surface station effect is gone and then the photo polymer comes and the surface

of on the top of this section and then again you rigid to have a appropriate level of the

photo polymer on the surface okay, The thickness can be controlled by controlling the sea movement

or this movement of the elevator if you bring it to the top It will be lesser thick okay

Of course it will some addition like addition effect or some kind of a thin layer of the

liquid always will be there and you cannot have zero thickness or let it be some depending

upon the viscous city of the photo polymer you will have the limitation on the thickness

so you race the elevator elevator is independently controlled see all these movements this sea

direction movement of the elevator and then see scanning movements they are controlled

through computer okay.

So they are synchronized with each other and controlled through computer okay see your

laser light intensity it goes up to a certain depth only It will not go full depth i mean

so it will go up to a certain depth because the focal point or the laser focus is only

at a one particular point so up to certain depth the intensity of the light will be sufficient

to accrue the photo polymer okay so this solidification will take place.

Only in the small thin layer okay so there are these factors as we discussed affecting

the resolution of the components first is lesser intensity like how much intensity you

have then motion of the beam okay.

How fast you move the beam if you move beam very fast like you will have like lesser thickness

of the line if you move beam slowly you will have a better thickness of bigger thickness

of the line so you can control that to have accuracy good accuracy then what kind of photo

polymer you use for this purpose then what is your focusing how accurate is your focusing

or optics that you used for processing and then exposure time okay.

These are the factors on which the resolution or the accuracy of the component is will be

dependent on and then in case of syramacic material you use a ceramic powder and then

you use a laser based sintering of this product okay.

Instead of like kind of having a liquid photo polymer okay now there are several variations

like you can have fixed optics and move the tank okay in the animation.

Which we saw the tank was fixed and the mirrors where like moving so there was a the moving

laser beams okay the problem with that is that the focal point doesn't remain a see

as use tilt your focal point is changed now it is not on the surface of the liquid anymore

it will be either inside or outside the surface of the liquid so there to avoid the problem

this is one variation which people try is like you the optics fixed and move the tank


Of course we will have the sea direction movement but "X" and" Y" standing scanning we do by

moving the tank okay then there are various ways of scanning one way we saw was galvanic

scanning mirrors like rotating mirrors then like you can have linearly moving mirrors

okay so the mirrors will move in a linear fashion the advantage hear will be like the

you can have your focal point fixed level with the linearly moving mirrors okay.

Will not get in to details of a optics how we can have and all the things but it is possible

then you can have a restores scan versus vectors scan what we saw was a vectors scan okay so

whatever in the section limits are the laser beam it changing it changing's its direction

at the limit of this section.

But in a restores scan the say even if you have certain of a circular section we will

move the beam to train the rectangular section and then you will switch on and off the laser

lights at appropriate points okay. so for example if we go for the this thing for this

section I will decide the limit points for this particular line okay.

Actually the mirror will moving to take the laser beam from this point to this point like

in a rectangular fashion scanning but the laser will be switch on at this point and

switch of a this point okay so this movement from here to here is kind of a not very efficiently

used okay.

So restores scan is not deferred okay vectors scan will be kind of much faster kind of process

okay there are other issues regarding like where you have velocity reversal and so it

will have wherever velocity reversal their exposure time will be more so it is again

like your how much accuracy you can sacrifice to have I mean because of like more time of

exposure you will have like little thicker sections.

There so it depends up on like the way you have designed your control system to basically

control on this parameters okay in here now this a dynamic mass process so you have this

mass his controlled by the computer which is dynamically changing you have seen these

botches with led display right so there this dynamic mass is something of that short you

have this pixels we share like other made to have dark point or to have transparent


Depending up on the pixels like weather.

It is dark or whether it is bright or it is transparent this mass will be produced okay

so say for example this is a whole of your led type of screen in which like if you want

to have to this kind of a section and you will all this all the other point will make

dark and then this part is make bright so that it is now transparent okay so that is

the kind of a philosophy in dynamic mass okay now the inherited disadvantages of this thing

is like you cannot have like a higher power of the laser for exposure.

Because it will damage this mass itself okay so you need to use a moderate powers of the

laser and then you need to expose entire section at a time in this process okay and then again

this other part of the or processor remains the same like you have this elevator here

which will load in the photo polymer tank and then will section by section he will be

the component but now this section is exposed at a time okay.

And entire section is exposed at a time till it is faster process this entire section is

getting exposed at a time if the processor is faster so you have this first section and

then like you will have second section of different size of dimensions and then you

will have the third section like that you will go on building section by section okay

so this is dynamic mass process now you can see that since here.

The section us expose at a time like and there is no line by line writing of the section

if the accuracy of the contuse of each section will be better than the scanning process okay

but you will still have in the sea direction accuracy the line as in the previous case

you was in the sea direction you will have this steps as they are you cannot do over

with that only thing you can reduce the these sections size okay.

And they maybe improve up on some accuracy in both the processes but always you will

have this stepping nature okay in the third dimension okay so this are the limitation

s that I as I mentioned this smooth 3d surfaces are difficult to fabricate stepping effect

will always be there and the mass production and this another problem or challenge that

mass production of the several components at a same time is difficult in this case because

you can have like see for that if you want to have the mass productions then you will

need to have multiple laser beams.

Working at the same time okay.

So far that is.

I mean some people have tried that I mean producing multiple section at the same time.

It is a technological change actually okay.

Then extremely small features are very defalcating to produce like we cannot go to sub micron

kind of dimension okay.

So 10, 20, micron onwards accuracy is reasonable good to achieve with these micros okay.

Now next we will go for laser micro motion okay.

We will have just a brief idea about with is laser micro motion and why it is useful

and what are the advantages things like that okay.

So what is magnesium for laser micro motioning is like you have a pluses laser beam like

you have laser beam.

But it is not expose directly it is given in the pluses okay.

Switching on and off kind of a so you will have these short pluses of the laser beam



And there in each plus there will be very high energy the livered to the material at

your prosing okay.

So these pluses they will be focused like you have a laser beam which is to be focus

on the surface which u want to machine and at the focal point like you will have these

surface so the entire energy in a very small location it gets consecrated okay.

And then the energy is delivered fashion of this process okay.

The typical a time for these first will be about micro second and nano second okay.

That kind of a process we are talking about okay. in some cases like most advances laser

which are say he as a faire that a name is a faire lasers they are giving a pluses in

a tempt second period okay. so like less ire is a period more is a cuirasses that you get

because like in a short time you are giving these high amount of energy to the Montreal

because of that like it doesn't get a changes Montreal to spread that energy okay since

delivered in a very short time there is no spread okay.

The energy and that results into very localize like effecting of the met real at your prosing

so very localize effect will be there so like shorter time more localize is the effect okay.

and because of that like more will be your corrosive of the machine more shorter will

be like a the scares at the leave age that you produce on the set face of the machine

okay. the main advantages of a laser micro machining verses the conventional machine

process are you have micro cuts on complicated two dimensional shapes.

So any complicated two dimensional shape can be in very easily off course you will need

X2 stages moments to have that shape or that symbol or arrant accuracy of the laser machining

will allow you to have very complex nature of two dimensional features cut out of there

much here okay, and then this is the mass less process there is no mass which is expensive

process just like if you want to compare.

Now with this material remover process with they have seen in conventional to dimensional

names process then this process is doesn't required mass okay, so that brings down the

past okay. then it has minimum energy in proton my that goes in to the laser might commissioning

okay, And then this is a another very important advantage is that there is a minimum damage

to the micro component.

Which is getting fabricated because the energy is very much very much localized it is not

spread on to entries surface okay, because of the local nature of the thing the area

which its getting affected around this local where ever having a cut its very short very

small area is getting affected.

Heat affected zone are the laser micro machining is much lesser okay ,and you can process the

verities of materials okay.

I will give you one example like say for you have ND YAG laser with power say 150 two 200


This has wave length of 1064 nanometers okay and his facilities fabrication of non metals

like you can presses ceramics and metals all source of metals we can presses

For example the of the steel thickness 50 to 200 microns or even little more they can

be presses like point 5mm or 500 micron up to 500 micron is a very easy to presses with

150 to 200 watt kind of inertia aciculate okay but now these since this power is consider

to be little on the higher side or moderate side so if you try to presses now the polymers

with these power or it will be difficult they will have like more effect.

I mean more kind of energy delivered they do not require that much of energy and if

you are delivering more energy than the kind of guts or kind of producer mechanizing accuracy

that will merge.

So you will able to process the but it accuracy will be poor so for that you go to exam modulation

okay these are laser mainly for processing polymer materials okay.

The metals are difficult to presses through these lasers and then this laser have wave

lengths of order 200 to 300 or 400 that order nanometers because of that you will merge

better accuracy on the surface okay so is like higher the wave length laser will be

there accuracy okay but we are talking accuracy in terms of a few nanometers or macro meters

okay for exciters lasers it will be very good or I mean from accuracy point of you okay,

were it can presses only polymer okay.

Now will see how these fabrication presses there are used for the purpose of robotics

application okay, we will have a look at these micro grippers or micromanipulators okay,

will have look at several micro actuators which can be used for future robotic applications

okay, here will see mainly the actuators which are not currently used for micro robots but

they will be they have high potential to be used for micro robotic applications okay,

and then we will see one very particular very nice design of a this mobile micro robot okay,

so it is called saturators so why it is called and all those thing we will see it ,okay.

Let us first start with micro grippers okay, now you can see here the principle here is

dependent up on the electrostatic actuation using comb drives okay, so comb drive are

basically you have these kind of comb like structure here you can see these are the teeth

mixing with another set of teeth on these part okay, when you apply voltage to these

gold conduct pads okay, then there will electrostatic force of attraction between teeth on this

side of the comb end other side of the comb end okay.

And then because of the electrostatic attraction will have these manipulator movement gripper

movement okay, that is basic principle of operation okay.

In terms of fabrication now we can see that these are freely moving structure which are

accrued at this point okay, so this is similar to the cantilever fabrication forces that

we saw okay only thing now the shape of the cantilever is different instead of the same

simple rectangular shape they have comb like structure proper ting auto care okay.

Otherwise the presses is exactly the same okay are you have like multiple options have

liver to fibrotic these multiple way in which we saw a two way in which the cantilevers

can be fabricated so you can use either of them or you can use another presses also to

have these cantilever structure in the comb shape form realized okay and then you can

do this gold conduct pads okay usually the conducts.

Which give the electrical signals to your structure okay, wherever necessary there are

made out of gold okay, but it is conductive okay.

So you will have this big pooled pads on which will have some shot of wire which will finally

connect these thing to the pin that you see out of your eyes structure okay, so inside

IC that you see conveniently, okay.

whatever pins you see outside there are connected to the point , where your actual pressuring

electrical is happening by very thin wire by presses called wire bond presses okay,

so see we seeing one end like it is the whole thing which is going inside the shape okay,

or these part like what your part you see up to these point that will be inside a chip

and what you will see outside only these part and some contacts okay, so there are the producers

this are the only the fundamental concept or structure there are many things that go

behind like for packing issues and other issues okay which we are not going into details so

these are the principle on which these micro grippers will we are there based and then

these can be fabricated by using conventional presses ,okay.

Now let us go to actuators there are different types of actuators possible advanced level

see if you thing for conventional robots what are the actuators possible electrical motors,

electromagnetic principle okay, and then may be hydraulic principle these are the two major

types of actuators which you have for conventional robots now you go for micro domain like you

have multiple possibilities like.

You have thermal actuators possible okay.

So I will explain how these basically on principle of biomatiles chip then you have piezoelectric

actuators possible then you have motors but based on electrostatic principles okay, people

have not used for memes devices a magnetic type of motors you will not see in the literature

in the magnetic motor, motor based on magnetic principle at very macro step okay, this we

are talking about the scale of like say few hundred microns okay that smaller size we

are talking okay, and then we will some cantilever type of magnetic actuators, okay.

So let us start with thermal actuators so as I said it is based on the bimetallic strip

effect see it is very easy to have multi layer kind of structure bit for with the memes technology

that we have seen okay, you have cantilever on the top of the top of the cantilever you

have one more layer and then your bimetallic strip is in place so now you have this structure

heated okay, that are multiple way like you can have localize hitting possible you can

just run some kind of a conductor on the surface of the liquid.

On the top surface of these layer and then you pass current with that you have I2R F

of hitting then okay, that is the resistive hitting and then that hit we deliver to the

structure will expand upper layer or contract or whatever depending upon what other coefficient

of thermal expansion of these two layers and then it will have these actuation possible

okay, because of the that differential coefficient of thermal expansion okay, that is the way

this thermal actuators okay, they are used for switching.

I mean currently if you see in the technology there used for switching in the sense like

you can have some mirror attach at this end okay, reflecting surface and then you want

to deflect the light from coming from one fiber to other fiber okay, so this kind of

switching between two light weather you want deflect the light or you want to or you want

to not deflect the light okay that king of thing you can achieve by using this types

of mirror based switching it is basically switching of the optical signal you know the

optical fiber there used to transmit the signal or you want to switch the signal you can use

the mirror okay, so that is current use but then see this can be used as well for the

robotic application ,okay.

Now piezoelectric effect is basically when you give there are some materials when you

give voltage to them they will expand okay, so these materials they are very compatible

very much compatible with their name base fabrication okay, you can incorporate very

easily these materials one of them is SIO 2 okay.

So these materials on the cantilever now you apply some current with these they will have

the piezoelectric and because that they will expand okay this is called the piece of patch

to apply on the surface of the cantilever and then this will bend when you will apply

the voltage in the piece of patch okay that Is the piezoelectric.

This type of actuators are all ready in place in many micromanipulation basically for something

called AFM (atomic force microscopic) okay that is very popular application this kind

of thing okay there is no I mean you can use these piezo actuation in a different ways

in micro structure I mean you can have this piezo actuation done on the substrate and

keep the cantilever keep the probing seen.

In the AFM is other way wrong you have a cantilever very micro or very thin cantilever okay which

is having a probing tip at these end that is very thin tip at the other end and you

give micro moments with the base or substrate by using piezo actuators okay so that is the

one of the application of the piezo actuators okay.

Next will this magnetic actuators it is cantilever beam type of actuation here the principle

is like you have this magnetic bead place on the top of the cantilever surface okay

then now there is a copper coil below the substrate will see how that is fabricated

will see the animation of the fabrication in a minute but there is a copper coil which

on these side on the lower side of the substrate okay when you now pass the current through

copper coil because of the magnetic field this bead will get attracted below and then

will get a that kind of attraction more the current you will have the more effect.

So let see the fabrication is done so you have the substrate which have used hippokics

substrate here then you have kind of the copper deposited okay you pattern this copper and

then produced a coil out of these okay is either coil is of these nature okay so you

pattern or you have the mask which way will produced this kind of structure on the surface

and then you exposited and do your teaching and then it will get spinner coil over here

okay if you take the section it will look like this okay.

Now on the top you again have is window open in which you will deposit whatever the cantilever

material you have okay on the top of that now you have another deposition like another

window will be open and in that you will deposit this bead okay now ones this bead is in place

then you can edge the entire material remove this part okay so and realize your cantilever

so this way your structure may of magnetic micro actuator will be getting now you will

pass the current with the coils and then you will get actuation okay.

Now these are the what we saw were all are actuators now let us see one very elegant

structure which is used to mobile robot oaky so essential you have these type of cantilever

structure which is free it is not attach to the surface.

Okay, it will look something of these slots when you see from side.

Okay, now you apply the voltage between these and they will substrate because of the electrostatic

charges here between these gape they will a electrostatic force of attraction and these

will bend down like this okay so now you increase the voltage then these part is going to be

scratch on the surface and move little further.

Okay, is part is fix since it is as a larger surface of contact and then see if you here

there is just line contact okay this part these is the surface type of contact here

and your applying more voltage more electrostatic force these as to bend little more so it can

do that by scratching the surface there is a line conduct at this point it will just

scratch on the surface and then it will move by a small amount on the surface.

Now you release the voltage okay then is will became the structure of these kind then it

will slide, slide to this part it slide little bit on these side.

Okay, so like that you do multiple times in pluses and then you will achieve the movement

this type of structures on the substance okay so this kind of a much cured kind of a mobile

robot I mean how to change the direction of the motion is the initial then how to change.

The orientation like if you want to take a turn how to do that these are the different

issues like how do you modify the structure to achieve that kind of thing there are the

issue but this is the principle or basic idea that the people have tried for that will have

there will wires connected for this contact substratum these robot this wire also will

have this own effect on the robot .okay,

These are the issues that one needs to deal with but these is a very in motive kind of

idea for mobile section or the micro robot.

Okay, so these are the two gentlemen's who tried this idea and is very recent like 2001

they have a paper initial find list.

Okay, it can made of anything actually the material they I think they used the poly silicon


Now let us see some other topics which are futuristic nature and which we have

e not going into depth of that but these are the again these are the topic.

Where, people are caring out we search so one of them is under actuated manipulator



So the essential idea here is that here you have manipulators which has numbers of degrees

of freedom more than number of actuators.

Okay, typically these kind of problem like for example you have these or conversely like

the example that we are looking at we were looking at these throughout is force this

2D or 2D of freedom to degree of freedom manipulator is 2R manipulator now you attach one more

link at these end these is the link is attach but there is no motor which is actuating these

okay now the problem is like how do you control other two motor such that these link goes

from say for example these decide position initial position to some other desired position

okay say for example.

If you have this in horizontal place okay no gravity effects how do you do that okay

these kinds of like are mainly related to control to under actuators manipulators a

controller is a big issue in such manipulators if we have seen for some BD control kind of

places okay so here you will need very completed control logarithm which will drag this link

from one position to other position in the specific manner.

So like we have actually that manipulator in one of our lap and some research is going

on that manipulator in this direction.

How to do this control okay now other thing to other point to mention about this under

actuator systems like this is the big domain actual if you see under actuator manipulators

or under actuator system is a big domain of system the very simple example is the your

aircraft it has number of degrees of freedom more than the number of controller surfaces

based on.

Which it is operated okay so that technology the problem is in the aircraft there are similar

to problems in the under actuators and typically for tackling these kind of systems you will

need good amount of physical understanding are physical inside so, What is happening

in the system okay in the system behavior so that kind of understanding you should have

very good understand of that kind so that like series developer good controllers to

control these okay then you have seen these example.

Already is a legged robot okay you have seen one of the example of natural which is six

legged robot and then in that in legged robot you have possibilities like you have a running

robot or hopping robot so if you have single leg it will be a hopping kind of something

it will just bum or bounce as to stabiles itself and then if change the direction of

the link on which it is copying then it will start moving in a particular direction okay

if it is vertical it will just bump under same point in place it will not move but if

you move little bit it is start moving in a direction which are posed to that okay.

So that is the very much studied I mean that people have like over the ears developed many

different types of hopping robots and many different strategies to control the hopping

robot so these is typical dynamic in nature like all these they are continuously moving

so it is not that is have fix position that they will achieve okay so they are continuously

in the dynamic equilibrium so you can go from one equilibrium to the another dynamic equilibrium

okay so it hopping at this place.

Now I want to hop at some other place so how do I move it from this place to go to that

place but I can do that but it will be always in dynamic equilibrium at the final position

also it will not be kind of stopped it will be have a dynamic equilibrium at that point

so that is the main difference from in the point of view of control in what we have seen

what control we have seen what is this type of strategy, okay.

Next is under water robot like if you have robot for under water application okay so

there are similar in nature technologically to aircraft kind of structure we will have

control surfaces we have a propellers we will propeller them in their bolder and then you

like problem is to control the surfaces is that you achieve particular a propeller motion

are particular it goes to a particular place something like that okay.

And then in addition to that you have to control the binary so that it moves with respect to

the water level okay it goes deeper and towards the surfaces if that there is a different

mechanism used to have that kind of motion possible okay, then you have which are against

to aircraft but smaller in structure there are many technology issues regarding what

kind of lifting force you will have nothing like so that is again technology change right

and then converting this flying robots into a autonomies flying robot is there okay, these

are the other futuristic issue robotic area okay, so will conclude these selection.

Of what were seen is basically micro phycrpy these are based micro version okay these are

the presses for like fabricating micro compounds but it are based on the unconventional kind

of presses okay then we saw some micro grippers and manipulators then one example of walking

micro robot and then couple of micro actuators okay and then some other futuristic topic,


These will conclude this lecture and then with this I think we are concluding the entire

course okay fine these case studies model will have all ready seen in the previous may

be will have some more case studies okay, fine.

The Description of Lecture - 22 Velocity Analysis