 So, in today's class we are going to look at elements of mechatonic systems, why do we need to understand these elements is basically if you take any system like CD-ROM drive or your scanner or any mechatonic system it can be broken into different parts to understand for our consolidated understanding it can be broken into chiefly four parts, we will look at these parts in this part of the course and then like now we will be in a position to think about many different system that I was talking about in the last class in terms of like these elements, so let us understand what are these elements, so let us go back to the slides, now we have seen like these different kinds of mechatonic systems, so maybe like no scanner hard drive these are like more kind of sophisticated systems, once you understand these then like the simple system understanding may not be too difficult I would say, so these systems are like where like a good amount of what you say the knowledge have gone into actually like no working in practical. So, we will look at some of these systems in much more detail in the future classes to come and then like now we will talk about as we go along like now some of the important parts how this theory whatever we study in different courses have gone into actually building these components and what works and what does not work and from the theory to practice that kind of a discussions we are going to have as we progress, so let us focus on what are the elements of mechatonic systems, see as you might have kind of already known or like no guest or whatever like the mechatonic systems deeply consist of these four elements okay sensor actuator controller and the mechanical system itself, so now let us kind of like no understand these with the example of say you as a driver driving a car okay, so you are sitting in the car at the steering and like no you are driving a car, what do you do can you imagine yourself driving a car okay you have can you think now what are the actuators for your system and you as a driving driver for the car as a part of the system what are the actuators okay, so what you are controlling the car with is like no your hands and legs and there is an engine to support you in terms of some sense of power but Indian does not have a smartness to kind of know when to kind of you know give acceleration to car or like when not to or when to stop you know that kind of thing we do not have with that smartness is not there with engine it smartness is there with you as a driver there okay then sensors are your eyes and ears okay then what do you do like no see suppose you are driving a car and some curve comes okay then you you naturally like no tend to stare the car in the in the appropriate direction to keep your lane so you are sensing like okay your position with respect by using the sensors like your eyes and then like no you are taking a decision in your head okay that is a controller that is acting in your head and it gives a command to your actuators okay which are hands and legs to kind of make sure that you know the the curve is negotiated properly okay so this is how like no things happen when we see like you know ourselves as a part of some mechatonic system okay so so the car is really not a great mechatonic system I mean in terms at least like no the driving part of it there are many small other subsystems in the modern cars nowadays anyway but we are not talking about that for now like no for now we are just focusing on like some basic car which is having just an engine and like no these different steering systems and things like that and you know so the plant itself is car car with this mass with your mass also included in that and some kind of another force coming from the tire attractions and things like that so I'm sure some of you might have worked with the Formula 1 car and like no you can imagine like no if you want to offer now this Martinist more and more on this on the system rather than human like no what are the things that we need to think about okay so see from this perspective if you see I mean in our life we are as a human being like we are having lot of this kind of a built-in mechatonic system in ourselves like in walking or in talking or in whatever you think of like no we are sensing some things then like no processing it in our brain our brain acts acts as a controller and then we are you know actuating something our hands and legs act as actuators okay so so this is very simple way one can kind of like no understand what are the different elements of mechatonic system you just think of yourself as a mechatonic system and you see that okay you have different senses you can sense things process in the brain some some kind of a decisions and then offer those control decisions to the actuators your muscles and legs and then they'll start operating you do that like no very often I mean you can imagine like no if you you are playing any game or you are doing any activity you can think about how you are kind of really taking those decisions now the crux of the matter here is that how you can kind of like no translate the the way you are taking decision to machine that is where like no the whole skill lies so see for example we do it by using like no our brain naturally we don't need to kind of process any mathematical numbers or something that that doesn't happen really when we process anything see for example you are playing badminton like no the the speed of shuttle and like position of the shuttle it's it's like no somehow kind of like no correlated in the brain somewhere and then like no you take a action to kind of hit it okay so so this whole calculations happen in a in a fraction of second inside our like no brain as a controller so now our job is to think see this is we anyway do this so now our job is to think what mathematics can kind of like no work the way same way as our brain is working okay so that is how like no we can start thinking and like no you can come up with like no different different kind of a control strategies analyze them and think like that so that part we'll do in the future at some some point in that course okay so these are the main elements of mechanical systems and now we are going to look at more and more details about these elements okay with the examples so see first example like no see simply a typical robotic system if you see the actuators there are motors or there might be some kind of a gear transmission system along with or there might be some hydraulic actuators via the cylinders hydraulic cylinders as actuators or pneumatic actuators and things like that then you can have different kinds of sensors for a work can you think of what are the sensors you'll have position sensors so encoders is a position sensor or potentiometer it will be another position sensor or you can have tachometers which are the speed sensors potentiometers again there can be linear or rotary potentiometers multiple return potentiometers possibility then you can have four sensors typically like no when you want to grip something in the by the robot you need four sensors to force sense the force of gripping and like no you want to grip it without breaking it like no that so suppose you want to kind of hold an egg or something then like no this will be very useful then you may have accelerometers you may have gyroscopes and cameras for the vision sensing and things like that then controller in a typical robotic system can be analog or digital okay so we'll see what what is analog and digital I mean you know these terminologies but like when to use what you know those kind of aspects we'll have a look at later then plant itself is like no mechanical construction of robots with the different links and mechanisms so so if you want to analyze robots that's why like no you're some fundamentals of kinematics and dynamics would be would be required and of course feedback is all maybe all the sensors are some of the sensors kind of giving you feedback say for example so some applications may not need a camera as a as a feedback sensor okay only position sensors are okay to kind of have a feedback from but camera can be just used as a monitoring vision say for example if you have a drone okay in that the camera is usually used for just like you know taking pictures when the drone kind of like goes from one place to other place but it is not used as a feedback okay but you can have have a robotic systems or say assembly systems where camera is indeed used as a feedback okay so it depends upon what kind of a application that you decide to drive why by by using these robots okay we this is one of the like no industrial example of robot so many different applications can be done with these yeah you can have spot welding application or like welding application or material handling system assembly system or some kind of like you know actually doing some metal forming operations and things like that okay so we will not get into construction of such robots and things like that but one can kind of like you know see once we have some basic fundamentals of this course in terms of like you know there is design strategies understood one can look at like you know the construction of such robot why people have taken such decisions to kind of have certain places only the links or certain places only the joints and things like that or placement of actuators at some certain places so those are kind of like no things one can kind of start thinking and like you know understanding how these fundamentals that we talk about in the course will be actually implemented there then you can have this autofocus camera as another kind of a mechatronic system now think of this again like you know what could be the sensors here so so one can see that okay there are systems like you know autofocusing okay so suppose here you have autofocusing what is a like you know what is the sensor for the system okay so you can have the image taken by the camera on the digital screen okay that itself as a acting as that image itself acting as a feedback for whether it is focused or not right you can have some parts of the image which are sharp and blur we identify the blur part and like move the lens and again like you know see the image getting sharper or not that is a way one can kind of see whether the image is in focus or not okay so we will see that you know some some sensors are of this kind are there for like you know in especially like the modern the digital cameras they'll have this kind of a systems in place one can see one can think of other system for autofocusing that that can sense a range of the object okay so you can shoot a light from i mean it's a invisible ray that can go from the camera to kind of some object and from that object the reflection of this ray comes back you sense it and you gauge the distance and once you have the knowledge of the distance you can adjust the lens according to that okay but that is again like you know some not feedback system but the intent of user may not get captured there so previously like you know the older cameras will we're having that kind of a system in place but now modern cameras they they'll have actually image sensing kind of a system and in fact you know some of these high-ended cameras will also have you know which part of the image you want to be in more in focus than other can kind of chases choices can be there with resting with the user or or they can be set automatically there's a lot of kind of different options that will be possible in the in the in the cameras now okay of course there are older versions of cameras will we're having a film i mean you might not have seen now nowadays nobody kind of like you know processes the film for the camera so this is kind of a somewhat historical kind of a thing i don't know whether we have some kind of things maybe i can try to find out some things if we have and this was then the film loading and film advancing you know those kind of features were needed that were automatically in the in the previous versions of camera but nowadays and we have we all have like you know this digital image sensors to capture the image so we don't need that okay this is another kind of a very interesting mechatronic system which is used for like no data storage okay so nowadays this cd rom drives also are nowadays getting somewhat extinct because we have the you know the pen drives or like you know this ram that is there for the storage device which is much compact and like you know much more kind of a reliable way the data can be stored it is less prone to damage physical damage at least might be electronic damages possibility but at least physical damage like no you can you may not have so this cd rom technology is also very very interesting optimization kind of a technology will go in like much much more details about this technology because it opens up a lot of interesting fundamentals to be exercised in many of the designs that you may carry out in the future so it has like no multiple subsystems like one is one of course will be like kind of positioning of the head or the laser which is reading the data from the surface of the cd now if you see the distance if you see here the distance between the two tracks is 1.6 microns okay you can imagine what is a 1.6 micron can you have feel for this number 1.6 micron if you think as compared to your hair size okay your hair size is about 100 microns okay so with respect to that you can imagine like no this is roughly like 2 percent of your hair size okay so that kind of a small number or small kind of a motion that you want to have so how do we design system which can kind of position something which is within the distance of at least like now if you would if this distance is 1.6 micron positioning should be at least like no 10 percent of the distance that is given right so maybe within like a like a 0.2 microns or 200 nanometers if you want to have the positioning how do we do that okay so those are the kind of questions that we need to address while developing the fundamentals of how do we kind of sense this position how do we actuator what kind of actuator will be there how people would take care of friction for such a kind of a positioning okay how friction will not bother such positioning you know those are kind of questions that would be raised and as we as we go along like you know we see some answers to such questions what kind of technologies people have developed to to really drive this you know very fine kind of a macaroni system application okay then there might be some additional kind of systems which is where you you just press a button and the CD kind of comes out of your CD ROM drive okay those kind of systems are also you know have some kind of a small mechatronics thingy happening there okay so we will we will see some of those actually so so we we may do this by like no actually I will show you some pictures now to to open such a drive and like no see what is there inside and then like to look at different parts and see what those parts are for okay if you have at your home or like no somewhere accessible some kind of older machines like CD ROM drive or some some floppy drive or some older computers may some kind of a systems here hardy systems for which are gone okay don't you open like no some new system okay it's it's going to be you may not be able to fix it back so that it will still be in working condition so you typically like no tamper with which systems which are like no not working so you may go to shop and like no repair shop and they'll have a lot of such systems to give away so you can take some of them and like no start opening and checking older mobiles maybe for example so if you do yourself this kind of an exploration that has a lot of value okay so I would suggest that you you do that in in some some way possible otherwise like anyway we are actually showing you in this course like no one or two systems I'll take and like we'll open up and like no see what all things are there inside and then talk talk and talk in details about that okay see this just opening is not of sufficient we need to observe that carefully and make sure that you know we understand what learning that is that it has to offer from from okay so for example this is one of the CD ROM opened here so you can see this some of these systems here so you have some some motors which are driving some gears here and then they are driving this slider which will slide along this along these rods here then there'll be motor which will always the CD CD will be kept and then the then the motor will be rotated and then this will be sliding so in this sliding like no how people are making this ladder see slider is there so that means the friction will be there here so how can like no one can have a system with the friction but we saw that okay friction you cannot position below like no 50 microns for example so how do you kind of position to nanometer range then what additional systems they'll have so there are some systems which are very close to the lens which are doing this positioning so we'll see if we all the details in in the classes to come this is another kind of a system that you might be familiar with as a as a child matter might have like or as a adult this is an interesting system both for childs and adults to play around with okay then we can have like no more details about these elements seen here okay now so these are different elements of mechanical system we are we are looking at and we'll now get into little more details about the sensors okay sensors you might have already like no study this is some part revision also and there are some kind of things from the perspective of mechanical systems also okay so you if you want you may skip this part of the thing or you may kind of like to brush through this is fine no problem like no these are what we are going to talk about is many many different kinds of sensors and how they are they are there is some relevance of that for the mechanical systems or their fundamental principle of operation if you are kind of familiar with like no no the sensor for some fundamental principles of operation the part of this like no somewhere a utility into mechanical system is a part which you might be needing to kind of look at okay so the sensor classification is basically based on output signal like type of the signal that is coming out of the sensor and then like no based on a principle of operation because these are two kind of a major classes that one can classify sensors into based on the output you can have analog sensor or digital sensor okay as the name suggests like no the analog output will be like a continuous signal that is coming from the sensor and digital signal will be like a like some number after some time like no some other number will come like no it is in the form of a number or digital number which is discrete kind of a number that will that will come so analog to read into microcontroller or digital domain you need some kind of a conversion to be done and so these digital numbers you need to have like some way to read again but there is no conversion that will happen okay so this is these are the two domains of you know output that the the sensor can have we'll talk more about analog sensor analog versus digital what you will prefer I mean if you if you think like no simply you know what based on whatever knowledge that you have so far or some kind of a common sense like no what would what you would prefer as a output type for the signal okay some of the people who are more familiar with electronics and electrical I mean you have also you are familiar with you have taken some course in electronics also but I don't know whether there is sufficient to kind of like no say this answer so if you think the the in the depth like no if you see analog sensor on the on the oscilloscope for example okay you'll see that typically analog sensor will have a lot of noise okay this noise is coming from many many different sources there is ambient noise that is there now we are talking of this electric noise electronics noise actually okay so this is like you know any wire you keep it on and like you know start measuring with something across the voltage across it you'll see that this wire acts as an antenna and wire keeps on kind of like you know giving some noise as a signal so so so in the electronics domain if you see like no people have to take care of this you know a lot of wires or a lot of like you know tracks that are laid on the PCB acting as antennas and they are kind of putting in some kind of a noise into the system okay so when that kind of a scenario is there you're you have it has a lot of repercussions on our mechanical system design so for example you need to filter noise or you need to do something about it if it is kind of coming in your way of getting the higher accuracy that you require for a given application okay so from that perspective you should look at like you know the sensors which will have analog as an output they are not generally preferred sensors in the in the system or if they are they have to be used then like no people will have a way to use it with a lot of filters and like no processing circuits and that's that's kind of additional cost maybe they'll have to incorporate it as compared to digital sensors which will have like you know just directly a digital output and why we just need to read it from the sensor and that's it like it will be ready for use in the microcontroller however with digital one will have a resolution issues okay resolution may be a little poorer than analog depends upon like know how many digits you like know used to represent the signal it depends upon really upon that so one cannot generalize the statement but analog by theoretical kind of a means analog sensors will have a infinite resolution okay if you just talk about theory not kind of consider this practical noise considerations then analog sensors will have a infinite resolution but it is not possible because of the noise that you get on the on the system based on the principles of operation we can have another classification for sensors you can have resistive capacitive inductive sensing then like no optical sensing or magnetic sensing or piezoelectric kind of a sensing so we'll just briefly look at these different different kind of a classes of the sensors now okay so yeah so we have just seen these like no analog digital discussion