 Good morning everybody. What I will do first is introduce you to what mechatronics is all about. So I will talk about my view of what the subject is as well as tell you happenings that are going on in IIT Bombay. So that will be one of the agendas and secondly to get you introduced to some of the terms as well as some of the notions, concepts and tools that would be necessary for you to understand what the subject is about. I presume that most of you are new to mechatronics in the sense that you would have heard this buzzword floating around and you are here to figure out what this is about. So that is my presumption and my lectures are based on that presumption. So let me get started off on these lectures. So this is a slide that I use often when I want to start lecturing on mechatronics. This is the first slide that I use especially to mechanical engineers because it is something that they can relate to. If you see this slide you have this is a familiar fly ball governor system that is used to regulate the speed of steam engines. I hope most of you are familiar with this. The idea is very simple. So if you look at the steam engine here, its job is to receive the charge that is steam and in the process of expansion of the steam it is able to drive through a turbine or shaft. And the shaft obviously is loaded by some mechanical load, we will not worry about that. Now suppose I told you that you had to regulate the speed of this shaft. So the objective is to regulate the speed of the shaft. A popular solution that has been adopted has been around for 300, 400 years now. This is the Watts fly ball governor. What this governor does is the following. It senses the speed of the shaft in a very peculiar fashion. Most people today would not do it this way. The position of these balls give you an indication of the speed of the shaft. The faster the shaft is the balls move further apart. So you can think of the fly ball governor shaft being coupled to this shaft. The position of these fly balls are then used to regulate how much steam goes in. In other words, suppose I want to regulate the speed to a prescribed value. And indeed the shaft was rotating faster than that. So what an obvious thing that you would do is lessen the amount of charge that goes into the steam engine thereby reducing the speed of the shaft. And this is obvious. You do not need to be an engineer to know this. So how do you go about doing it? If you want to put less steam inside, you open the steam valve by a smaller amount. That is also something that most people can appreciate. And the way it is done here is the position of the fly ball itself is used to actuate a series of linkages which closes or opens the valve. Is that clear? What happens? So you can imagine it. Your fly ball moves this way and there is a set of linkages attached to the fly balls which will open or close a valve. If it moves closer it opens it, it moves further apart it closes it. So this is the speed regulation mechanism that is most popular in steam engines. In fact all diesel engines even today in tractors use the governing mechanism very similar to this. So it is a mechanical governing mechanism. Now the reason I have taken, I mean I talk about this example is first that it is easy to appreciate. You know how to regulate the speed of the shaft just by opening or closing a valve and you can think of it in mechanical terms. But there is something more involved that I will be discussing. Obviously there is an observation here which is going to be critical to your study of mechatronics. If ever you are going to do a serious study of mechatronics you will have to pay attention to this observation I am going to make right now. The observation is as follows. There are two things that are happening here. One is that you need to decide based on the speed of the shaft, the main shaft that I have indicated here. You need to decide how much to close or open the valve by that is a decision that needs to make that you need to make right and coupled with that decision in this case is the actual job of moving it. So there are two things that are happening here. One is that the linkage mechanism is designed in such a fashion that if the fly balls move out by this much amount then the valve is going to close by this much amount right. So the linkage mechanism is designed for the steam valve to close by an appropriate amount if the fly ball governor goes in and out by a chosen amount. That decision is coupled with the actual job of moving it, moving the steam valve. So what do we mean by coupled? The same agent that makes the decision on how much to move by which is the linkage mechanism also does the job of moving it. So there is in this case both the decision maker, the brains of the system and the leg work is done by the same element, the set of linkage elements. Now this sort of a characteristic of regulation of different variables of interest in mechanical systems being done by the same agent responsible for both decision making and the leg work is very common in non-mechatronic systems. So mechatronic systems are characterized by separating these two things where the decision making is separated from the job of actually doing it which is called actuation. So in philosophy even our human body works like that. The element that makes decisions is the brain. The brain does not actually go and move anything at all. The brain communicates its decisions to different actuators which are the limbs, hands, legs of the body, fingers and the fingers are responsible for actually turning a screw for example right. It is not the brain that is actually turning the screw but the brain provides the necessary information for the hands to behave in a certain fashion. So this is the observation that you probably need to digest. Most mechanical design, mechanical only designs will have this feature that the decision making element and the power communication element are one the same physically. Now this has some advantages and lots of disadvantages that is the reason why we are into mechatronics now. If you do this where the linkage in this case is both responsible for power transmission, the physical job of moving something and it is also a computational element which decides how much to move by then there is a severe limitation in the level of complexity that you can achieve. Most of you who have done some course in kinematics of machinery or something like that you would have done some linkage design where I want a certain tool path to be traced by some end effector and you decide the nature of the linkages and also the interconnections between them what kind of pairs you are going to use etc. I am hoping most of you are familiar with what can be achieved through linkage design. So anybody that has done linkage design at least one paper will realize that you cannot get arbitrary motions that you want at the end. The motions that you get are severely constrained by the linkages, their lengths, the kind of joints you use etc. What you get at the end effector cannot be arbitrary first of all. There is a problem of flexibility. So once you design a linkage it is designed. If you want a different characteristic to appear at the end effector then you have to redo the whole linkage design and you have to realize the linkage design differently. So these two problems are very severe in the cases where you want a single machine that is responsible for orchestration of different tasks to do some complex decision making as well as power transmission. So you lose out on computational complexity and you lose out on flexibility. Flexibility in the sense that if you want the same infrastructure to do a different task you cannot do it if you have this feature of both power transmission and competition being done by the same element or it is severely limited the complexity that you can get. So this observation forms the basis for why mechatronic systems have been built in the first place and are being built. So mechatronic systems in mechatronic systems you will have the defining feature that through some process there is a separation of decision making from actuation. So that is the design paradigm which is often called as mechatronics. So it is not about putting some electronics in a mechanical system that is the traditional view of it. I have some mechanical system and I put some electronics and now it is a mechatronic system. So as opposed to that I think it is useful to think of mechatronics in this way as a design paradigm where decision making is separated from the job of actually doing something. And it has so happened that in the last 20-25 years because electronic components have become cheap especially power amplification devices, cheap as compared to what they were 50 years back. So there is a device that you will often find in a mechatronic system which is doing some task of significance called the power amplifier. And this power amplifier is in some sense the heart of the system in the sense that it is what lets you separate decision making from the actual task of doing it. So let me explain how that happens and hopefully this picture that is in front of you will make more sense once there is some clarity on what is happening. If you look at these components this other components computation operator interfaces instrumentation etcetera all of them deal with the process of decision making. So I will come to that do not worry if you do not understand this slide just off hand you do not have to start noting down everything and you know this is not a lecture that you will have to reproduce anywhere. So if you think of these elements as the decision making elements right. So for example the computation the software that is sitting inside a microcontroller or an algorithm that is sitting inside a microcontroller it is a decision making body. Just because you know how to do something it does not mean that that thing will get done ok. So there has to be an execution body as well right. So consider all this as decision making bodies and this actuation and this target system that responds in a certain fashion they are the physical systems that need to be moved that need to be supplied with some hot steam or whatever it may be they are the physical systems that you need to control. So something has to happen in them ok. So that cannot happen if this device is not there is yellow color device which is the amplifier. So what the amplifier does is on one side of the amplifier you have all these devices that consume energy that need energy for their existence or that need energy for them to do what they are supposed to do ok. And on the other side you have devices which make decisions they also consume energy but very small amounts in comparison to the ones that I highlighted in the bottom here ok. So let us again go back to the human brain and human system example. So you have the human brain and you have the hands these are the actuators and this is the brain that is responsible for making decisions. In between there is something how does this thing start moving all of a sudden just because I tell it to move. So the nervous system is the answer the nervous system only communicates decisions. Suppose you do not eat anything at all ok for 5 days if I ask you to run from here to there you will take forever right your legs will not move. So there is energy that is built up in the body because of some ATP process happening where food is ingested and energy is stored in some molecules which are released when required ok. So external energy is supplied ok in our case through food ingestion which will help realize the decisions the brain wants to take. The nervous system does not move these things ok it is muscles muscular there is a muscles which is responsible for the motion and they need to be supplied with energy ok. So it is a very similar thing the power amplifier receives information from the brain which is a computational element and it receives energy the food from outside ok and it moves these limbs which are the actuators. You do not want to move the limbs just like that right you have to serve a purpose you have to lift an object you have to do something right. So lifting an object etc the limbs are responsible for the lifting but the object is the one that gets lifted and it has its own behavioral characteristics. For example if you lift the object and drop it is going to fall down so that is a behavioral characteristic of an object like this wallet ok but other objects that you are dealing with will have other behavioral characteristics ok. So the actuators are responsible for dealing with the physical environment that you are interested in ok right and the actuators get the energy from external food supply ok and the brain is responsible for making the decisions alone. Now let us take a task of picking up an object and putting it in some other place so I am picking this object and putting it here ok. So the actuators have energy and the brain is telling the actuators what to do but what is the brain making the decision based upon any answers yeah but I want you have to tell me in this case what is the brain making the decision based on the eyes right. So if I took my eyes out of this scheme of things ok I will find it difficult to put it here unless I know that it was already in this place ok. So suppose I move this table away and I do not have eyes it will be very difficult for me to figure that I can put it here ok. So the decision taken by the brain on where the hands need to go ok is based on where it wants this thing to go and where it actually is two things ok. So where it wants it to go is only a job of the brain you can code the brain to say that I want to I wanted to go to a certain place but where it actually is that the brain alone cannot do you need the eyes ok. So the eyes are the sensors ok they are responsible for telling the brain what is happening to the system that you are trying to influence ok. Now this information that is communicated by the eye to the brain though there is a little energy conversion no physical process can really happen without some energy being transferred from one place to the other. The quantum of energy that is involved in this in communication of the information of where do you where does this stand to the brain is much lesser than the quantum of energy involved in actually lifting this object ok. So that so the sensor the decision maker which is the computational element these two elements along with other elements that may be involved which I will briefly touch upon later. They do not consume significant amount of power they are responsible for communication of information ok. The actuators that the limbs and the physical thing that you are trying to control to influence them you need a substantial amount of power ok. So there has to be an element in between which does the job of taking information and translating that into power ok. So that is done by the power amplifier it receives commands on what to do from the brain it receives food from the outside and actually does the job alright. So in all mechatronic systems you will have this device which is the power amplifier which is responsible for which allows you to separate decision making from actuation. And this has been made possible because of the growth of power electronics ok in the last 20, 30, 40 maybe years ok. And you can communicate a significant amount of power significant I am talking about hundreds of watts possibly kilowatts etcetera through electronic means ok. So the power amplifier will listen to information from the brain only listen to that information receive food from the outside and actually do the task ok. So you will see a power amplifier in your experimental set up that you will deal with in the afternoon ok. So it is not that the power amplifier is big or anything like that ok. So do not think that something will be written saying power amplifier. So you will have to start looking for a power amplifier if you are talking about a mechatronic system that is doing some significant task. If it is not doing any task which requires reasonable amount of power you will probably have this device being replaced by something else ok. So this picture that you see in front of you you know highlights what has already been said that of a feedback system. So you have a power amplifier communicating power energy to this to the limbs which impact the system of interest what happens to the system of interest is sensed by a set of sensors communicated to a brain which is the computational device. And the computational device impacts the amplification process ok so it communicates what to do to the amplification process ok. So this design paradigm of separating decision making from actuation is what mechatronics is about and after this I guess once you understand this design paradigm now there are some technology issues to understand that is how do you go about doing this? It is one thing to understand that you have to it is useful to separate decision making from actuation and there is a whole other thing for you to get involved with the technologies that will help you achieve design of mechatronic systems where decision making is separated from actuation ok. So a lot of what is going to be done through this course as well as through the labs is to familiarize you with the technology involved in realizing this separating decision making from actuation ok. And there is no way to learn how to deal with a certain technology but actually do it. You cannot learn mechatronics by lying on the bed and reading a book it is impossible ok. Because fundamentally there is only this idea beyond this is only a matter of your understanding of the physical system, your understanding of the technologies and how to deal with the physical system, your understanding of electronics, your understanding of micro controllers ok. And there is no way but to actually do it. If you really want to learn how mechatronic systems are built, if you want to just get a flavor then this course will more or less do the job ok. So any questions if there are no questions what I will do is I will give you a brief introduction to a couple of projects that I am involved with and show you I mean there are a lot of elements in the project which do not directly warrant this discussion. But I will point out to you where mechatronics fits in into them right and just to give you a flavor of the kind of things that you could do or the kind of things that are happening out in the world for you to place it in the context of separating decision making from actuation. I am going to give you a couple of examples. Then we are going to take a break and we will come back and start discussing the structure of the computational element that is out there today ok. So the predominant computational elements are the computational elements today are all digital computational devices ok. So they are built in a certain fashion for a certain reason ok. So I am going to talk to you about the architecture of these computational devices and you are going to you have probably have seen some of them you are going to see a few more in the lab ok. And you hear these names all over the place every day microcontroller, microprocessor right. So part of the part of the agenda of this course is to demystify all this microcontroller microprocessor business ok. So hopefully that will that will get through. So I will talk to you about the structure of modern day computational devices you know amplification of power modulation. Yeah. So do you see anything that is only your mechanical amplification in the system? Most of all gearing does not give you amplification. The power on either side of the gear is the same ok if there is no frictional losses. Now I understand your question the whole point of this is this course is to say that there are certain tasks that are better done where the decision making is left to the electronics ok. And you have power amplification devices which have to communicate with the microcontrollers. So they have to deal with them with in terms of voltages and currents ok. So if you are going to have computational devices which are built based on electronic systems of today then you will have to have power amplification devices that can communicate with those decision making bodies ok. And they have to be electronic in some sense because they have to deal with voltages and currents. Microcontrollers can only deal with voltages and currents at the end of the day ok. So your question of whether mechanical only amplification can happen yes sure mechanical only amplification can happen it happens all the time before electronics existed you could still do tasks. No the hydraulic cylinder forms this target system so you are you want the or this actuation system the hydraulic cylinder gets information on what to do to a certain extent and also power from your flow control valve it is not the actuator will not take external power the actuator may take external power for example if you are driving motors right. So the external power comes through the power amplifier to the actuator. But if the motor is driving something else ok then that something else can take power from the outside world there is nothing that prevents it. So for example in your case the hydraulic power pack which is driven by a pump is responsible for making sure that the cylinder actually moves. But it is how much it needs to move by etcetera is orchestrated by a valve flow control valve which is again actuated by some solenoid actuated device probably. So see we are not going to get into the specifics right away ok neither am I ever going to discuss hydraulic system the minumatic system and things like that ok. So if you understand the basic philosophy and the tools required for the synthesis of mechatronic system it does not matter whether it is hydraulic or pneumatic ok you have to deal with the specifics anyway ok. So nowhere in this course are you going to deal with I am going to build a hydraulic system or I am going to build a pneumatic system and we are not going to do anything like that ok. You will probably be exposed to some devices which are common in hydraulic systems pneumatic systems right but you are we are not going to sit and synthesize anything only for hydraulics or only for pneumatics ok. So we are going to look at things with a broader perspective and hopefully equip you with a requested tools for you to go and go ahead and do something ok or if for you to just get acquainted with what this is all about ok. So I am going to give you a couple of examples again by no means covering the entire gamut of areas where this mechatronic separating decision making from actuation idea applies I am only going to give you examples that I have been involved with. So it is very parochial in its view that is very local in its view ok but will in some sense highlight what we have been talking about ok separating decision making from actuation ok. So I will talk about two examples on what is happening in the automobile industry ok. So the automobile mechatronic boom as we speak is currently on ok it has happened in the machine tool industry since late 80s or early 80s ok the mechatronic boom in automobiles is beginning mid 90s I would say ok. So progressively you see more mechatronic solutions replacing traditional mechanical complexity ok. So what do we mean by these huge words? Traditional mechanical complexity for example you know that there is something called the crankshaft in most automobiles right internal combustion engines produce power they rotate a crankshaft ok. Now the crankshaft the speed of the crankshaft is used to orchestrate a lot of things in the car I do not know if you are familiar with that for examples when the valves need to move etcetera is determined they have to go at half the speed of the crankshaft in a four stroke device etcetera there are lot of things that are orchestrated based on what the crankshaft is doing ok or what speed it is rotating in. Now in the traditional mechanical only word you used different pulleys and possibly linkages cam operated etcetera to translate the motion of the crankshaft you take power from it as well as communicate the desired motion to different devices ok through mechanical only means ok this stuff is soon disappearing ok. So in 10 years down the line if you are if you look at a vehicle you will see a lot of things that you do not currently see in automobiles ok right. So this mechatronic boom has led to a lot of effort over the last 15, 20 years and also now in getting mechatronic ideas into automobile space ok. So I am going to discuss two things two projects that I have been involved with which have which do essentially the same thing replace mechanical complexity with mechatronically control solutions ok. So these two projects is what I will describe ok. So the global trend like I mentioned is that you want to replace mechanical complexity with intelligent mechatronic solution then the perceived benefits have already all kind of spoken about you have reconfigurability that is the flexibility in the design in many cases better vehicle handling in many cases cheaper ok because you do not need physical mechanical parts that are expensive to make decisions ok and in some case reduce driver fatigue etcetera. There are lots of advantages that the driver as well as the automobile industry is really interested in it does not make sense to do this everywhere but it makes sense to do this for certain subsystems ok. So I will talk about two of such two such problems I will talk about the this problem first because I think it is people are more familiar with this. So I will so I do not know how many of you have heard of this term engine management system for automobiles some of you may have heard it is a buzzword does not mean anything by itself ok I manage the engine right. So most people who have driven to two wheelers or even the older four wheelers will know that there is something called the carburetor in it. You see automobile mechanics fiddling with some screws in some carburetor cleaning the carburetor ok whether you know whether you have actually seen it or not you have heard somebody talking about the carburetor ok. So the carburetor's job is to mix air and fuel ok this carburetors are used in gas oil engine engines that is petrol powered engines. Its job is to mix air and fuel when you move your throttle in your in your bike what you are doing is letting in more air when you open it. The carburetor mixes an appropriate amount of fuel and provides it to the engine ok. Now I have to give you a story first before you understand what may where mechatronics fits into all of this ok. So you have to listen to the story otherwise you are going to lose the plot. So the carburetor is responsible for mixing air with fuel and communicating a combustible mixture not all mixtures of air and fuel will combust ok for combustion you need oxygen that is why you are putting in air and it gives a combustible mixture to the cylinder. So inside the cylinder what happens is that you first take in the combustible mixture you compress the combustible mixture raising its internal energy and then you ignite the combusted mixture sorry the compressed mixture. When you ignite a compressed mixture is like a bomb so it explodes and in the process of the explosion you communicate energy to the piston and which is taken through the linkage mechanism that you would have solved 100000 times to the crankshaft ok. So that is the slider crank mechanism ok then once it once the mixture has been combusted what is left there is of no use so you have to throw that out. So you put it out into the exhaust ok and then take another ingest another combustible mixture ok. So this is what happens in an internal combustion engine ok. So I just describe what happens in a gasoline engine. So there is a fuel air mixture preparation there is ingestion into the engine compression followed by ignition and exhaust ok. So these are usually these strokes can be physically separate in a 4 stroke engine or kind of mixed in a 2 stroke engine ok. So this process has been going on in cars in the west until the late 80s almost all cars were corroborated in India until 1999 or 97 sort of all cars were corroborated. Since then all cars in India since 1998 as well as the cars in the west since 1987-88 have all been are all fuel injected vehicles ok. Fuel injection means the nature of the mixing of air with fuel is different. So the carburetor is thrown out there is no carburetor in fuel injection vehicles ok. So you move a throttle so as throttle is just like a valve it will let in air if you open it close if you do not open it ok. So that is what you are controlling when you are doing this and depending on how much air comes inside you inject a certain quantity of fuel. In the case of the carburetor the mixing happens because of some complicated venturi shape that exists inside ok. You know that if you have a convergent area ok velocity is increased if you are operating below speed of sound ok and because velocity increases the pressure decreases and because the pressure decreases and you if you connect a vent to the fuel line fuel is going to get sucked in because fuel there is at atmospheric and this will be less than atmospheric. This is how a carburetor works so very complicated mechanical device lots of holes here and there and that need to be this has to be plugged in screws here. So it is a it has evolved into a highly complex mechanical device. So if you start dissecting a carburetor today you would not understand what is happening inside that ok. So the story is that most cars not most cars all cars sold today are fuel injected cars ok but all bikes sold today are carbureted bikes ok. Now why do you need fuel injection? Why do you want to move to fuel injection? The main reason is that you can accurately meter the amount of fuel that you can put in ok. So in the carburetor it just happens that a certain amount of fuel is taken in ok and the and the decision on how much fuel to take taken is coupled with the mechanical design with the coupled with the process of actually taking in that fuel. This is the same problem that you that existed with with the Watts governor fly ball governor. How much fuel to take inside is coupled with the job of actually taking that much fuel inside through the mechanical design of the carburetor ok. As opposed to a fuel injection system where the decision on how much fuel needs to be put inside is taken by usually an electronic device or computational device and the job of actually putting in that much fuel is orchestrated by a solenoid controlled injector ok. So the the computational device tells the solenoid open the solenoid opens tells the solenoid close solenoid closes. The energy for opening and closing comes from the outside world it is a food ok. And in the process of opening and closing you can accurately meter fuel going into the cylinder ok. Now what is the use of accurately metering fuel going into the cylinder is because you are worried more and more about the emissions that come out of the tailpipe. If you do not accurately meter fuel the devices that that a lot of people have started talking about since 1990s I guess in India catalytic converters they do not work well if you do not make them operate in a certain region of operation. So it is important that what goes into the catalytic converter has a certain composition that composition cannot be maintained if you know if you do not accurately control the fuel ok. So this is the whole story of why you have moved away from carburation to to fuel injection system ok. And we have just replicated this story for bikes ok. So group in IIT Bombay that I have been involved with has built a fuel injected bike that gives certain emissions and fuel economy etcetera. And the fundamental idea there is to replace the mechanical complexity in the carburetor with electronically controlled fuel injection solutions ok. So this picture so that is the story this picture describes what what happens in a typical electronically controlled fuel injection solution ok alright. This these blue lines that you see here can you you can see blue and red right yeah. The blue lines you see there are decisions that are taken by the computational device ok. So what decisions do you expect the computational device to take if you have to drive a vehicle what decisions do you think the computational device has to take. Speed of the vehicle is a result of throttle opening is a driver's job if the computational device is taking that yeah what do you mean by fuel injection how much fuel to inject and when to inject ok. And when to spark ok these are the usual decisions that are taken by yeah what you mentioned is also comes in what are known as drive by wire throttle systems where the throttle opening of the driver is not exactly replicated all the time ok. So there is some element in between which will decide how much the throttle really needs to be opened by should it be opened by what the driver demands or should it be opened lesser or more ok. But most of the time that is not there. So you have fuel injection fuel injector needs to be told how much fuel needs to be injected and that is decided by the amount of time you are going to keep the fuel line open ok. And when to inject is also important and when to spark ok. So these decisions are made by the computational device they are communicated to power amplification devices individually. So the fuel injector is going to the solenoid is going to be drive driven by a fuel injector driver ok so power amplification device. And similarly the spark plug so you can decide when to spark but actually the spark has to be produced ok at pretty high voltages for the sparking action to happen right you need to maintain a high voltage over a very small distance ok. So that is what is happening in a spark plug. And so this job of actually producing high voltages etcetera is done by external circuitry which receives the command on when to spark ok. So these blue lines indicate that the decisions on of the controller or the decisions of the computational device the red lines indicate the pieces of information it requires to make those decisions ok. So that is the computational device only deals with information it will deal with feedback information that is information on what is actually happening in the system and it already has an idea of what it wants to happen in a system ok. And based on these two based on comparisons it decides what the system should do right now ok. So these sort of arguments are common in feedback control design. So the pieces of information it makes its decisions based on ok. One is you need to know where the piston is with respect to its stroke because you need to spark at an appropriate point so that you produce enough power ok. So the crank position is important. Crank speed is also important because you make decisions based on that ok I will not be able to go into the details of that right now ok. One piece of information that you may not know if you are not exposed to automobile systems is that cars of in cars you have a sensor called the exhaust gas oxygen sensors ok. So that measures the amount relative amount of air to the amount of fuel that exists in the exhaust gas that comes out ok. Now the whole point of fuel injection actually revolves around this technology in some sense that if you can measure what comes out then you can suitably change what goes inside such that the measured value is equal to some desired value ok. So like a briefly told talk to you about catalytic converters ok. So I will just show you a picture of the efficiency of conversion of harmful pollutants into less harmful ones by the catalytic converter ok. So what comes out of the exhaust what is there in the exhaust yeah. So what so you have to worry about what is fuel composed of it is carbon and hydrogen molecules with some additives then you have oxygen and nitrogen because you cannot just supply pure oxygen you are taking in air ok. So if you burn all this you will produce species which use these as elements carbon hydrogen nitrogen oxygen ok. So the species are mainly carbon dioxide and water ok if you combust hydrocarbon like butane octane you will get carbon dioxide and water. But you also get other things because the combustion is not complete you get carbon monoxide you also get unburned hydrocarbons things different hydrocarbons which are produced as a result of breaking of octane for example. Then because the temperatures are high you get nitrogen and oxygen combining nitrogen is usually an inert element ok that is the reason we are surviving. But if you raise the temperatures beyond a certain point ok this will not happen due to global warming but it will happen at very high temperatures then nitrogen and oxygen will combine to produce oxides of nitrogen which are called nitrogen oxides. So the laughing gas is one oxide ok so N2O NO nitric oxide. So all these things come out of the tailpipe all sorry come out of the engine ok. Now the automobile industry does not consider carbon dioxide as a pollutant at all ok it considers carbon monoxide because carbon monoxide is a lethal gas so is a highly dangerous gas if I put in a carbon monoxide chamber you will die in 2 minutes ok. So carbon monoxide hydrocarbons unburned hydrocarbons which are bad for alveoli and lungs and nitrogen oxides which are also bad for other reasons these are considered as harmful pollutants ok. So the emission norms are regulated based on what these harmful pollutants have to do ok. So what you want ideally is these harmful pollutants carbon monoxides unburned hydrocarbons and nitrogen oxides should be kept within the emission limits ok and those are getting stricter and stricter. So the what comes out of the tailpipe needs to be lesser and lesser in terms of these harmful emissions you produce more carbon dioxide it is ok for now ok. So what comes out of the engine is not what comes out of the tailpipe there is some device in between ok which is called the catalytic converter and its conversion efficiencies work this way the plot that is shown here is hydrocarbon, carbon monoxide and nitrogen oxide conversion efficiencies. So what do you convert them to carbon monoxide is converted into carbon dioxide ok nitrogen oxide is converted into nitrogen and oxygen ok hydrocarbons again converted into carbon dioxide in water ok see these are considered less harmful. So how efficiently you convert them depends on the conversion efficiency of the catalytic converter ok. Now if there is more oxygen more air ok then it is easy to combust the carbon monoxide and hydrocarbon ok and produce carbon dioxide in water if there is but unfortunately if there is more air nitrogen oxides will not get reduced to nitrogen and oxygen you know reduction is taking away oxygen and oxidation is putting in oxygen right some chemistry basic chemistry. So it so happens that these catalytic converters because they use noble metals as catalysts the conversion efficiencies of all these three things are maximized in a very tight region around the around stoichiometry so I will not get into that that is the appropriate amount of air that has to be mixed with the fuel for it to burn properly ok. Now for that reason you need to maintain what comes out of the air fuel mixture to appropriate amounts ok. So the air fuel ratio of the mixture coming out of the engine should be kept very close to stoichiometry and that is the reason why you need fuel injection because fuel injection allows you to meter fuel properly ok accurately not I should not say properly. Now what comes out of the exhaust needs to be sensed that is like just like you need a rise to say where this is you need to know what air fuel ratio actually comes out so that you can make decisions based on the difference between what actually comes out and what you want ok. And that is sensed by a sensor called the exhaust gas oxygen sensor which gives you an indication of whether there is more fuel or more oxygen ok alright. So one example where this mechatronic idea of separating decision making from actuation the idea there is to throw out the carburetor and put a fuel injection solution because you can accurately meter fuel and the decision of me how much to fuel to put in is separate from the decision of actually putting that from the job of actually putting that in ok which is unlike the carburetor ok. I am going to talk about another example this is also a project that we have been involved with this is with regard to steering system of an automobile ok. You know the job of the steering system is what is the job of the steering system in an automobile is to maneuver the vehicle along a trajectory desired by the driver ok and you are familiar with automotive steering system with have this hand wheel and you do this and the vehicle starts moving around right. So the steering systems of today come in a lot of flavors you must have heard of power steering where the effort that you need to put in is reduced ok. So what I am going to talk to you about is steer by wire that is there is no there is no mechanical interconnection between the hand wheel and the road wheels unlike power steering power steering still has mechanical interconnection. In a steer by wire system so you have so on the left here is a traditional mechanical system ok and on the right here you have a steer by wire system just a picture of or a you know a schematic of that where all this mechanical complexity in between the hand wheel and the road wheels is replaced by mechatronic solutions ok. So what do we mean by mechatronic solution so just think of it along the lines that we have been talking about right now. So in the job of steering a vehicle there are two things involved one is the driver needs to communicate how much the wheels need to move by that is a decision the other is actually doing the job of moving the wheels so there are two things that are happening ok. In a mechanical only not even power steering system this both these are coupled because of the linkages ok whereas in a in a by wire system or steer by wire system the decision on how much to move the wheels by is separated from actually moving the wheels. So there is the driver communicates what the trajectory needs to be ok and what each of the wheels need to move by is decided by a controller ok and the actual job of moving the controller or moving the wheels is done by actuators which are motor motors that are driving it ok. Again what you are doing here is your traditional mechanical complexity in a steering system. It is pretty complex if you look at a steering system it is it communicates to the wheel through some set of linkages which are bouncing around when the wheels go up and down ok. So they are they are not simple linkages they are actually lot of spherical joints involved there ok. So the complexity in a steering system of today is I mean it is not the most complex part in an automobile but it is complex ok. So that being replaced by a solution where you replace this mechanical complexity by electronically controlled solutions ok. Now why would you want to do it I will briefly mention what the advantages of doing that are one of the one of the touted benefits is that in the event of a front because you do not have a steering column at all now in a steer by wire vehicle there is no steering column there is nothing that no rod that goes ok. So you this can be a toy you can place it anywhere in the car you can see literally sit in the back seat and drive ok. So since you do not have a steering column in the event of a front end collision most people die because the steering column jets into their face ok. So you have this this advantage the steering column will not there is no steering column so it will not jet into your face that is what is called passive safety ok. So advantage of passive safety secondly the amount of effort that you need to put into drive a vehicle goes down it can be literally be driven by a by a child ok. So you can drive it with a single finger. So that is the benefit that come these are benefits that come for passengers or drivers of the vehicle the benefits that go to the automobile industry are that there is no difference between a left hand drive and a right hand drive now the same set of components can you just need to take this user interface and put it on this side ok. So that is the benefit for the automobile industry secondly the many of the mechanical components being done away with you do not have you do not it is possibly a saving on on costs of fabrication ok. So that is also a touted benefit and lastly you can make the vehicle do things that usually does not do because now you have sometimes independently controlled wheels so your handling in emergency situations is better at least you can exploit the benefit. So there are several touted benefits of steer by wire ok and we have been involved with building a steer by wire vehicle here ok. So let me briefly tell you how steer by wire works maybe this picture ok on the hand wheel side you have something that communicates how much the road wheels need to move by ok. So the hand wheel communicates information on what the driver really wants to a controller which makes the decision on what the road wheels have to do ok. The actual job of moving the road wheels is done by actuators I do not think you can see much of it over here but just to get a sense all this is these shots the bottom two shots are from below the vehicle ok. So the these are actuators that physically move the last set of steering linkages to move the road wheel ok. The actual job is done by these motor driven actuators and the decision on how much they need to move by is dictated by computational devices ok. So I will not get into the details of this too much I just wanted to give you a flavor that what we are talking here is not in not an air it is not like a it is not that something is happening make a tronics kuch to kar rahe you know all these things are really going on in the world when it is the more that you are familiar with it if you are a decision maker you will be able to make decisions on whether to go with this sort of design paradigm or not ok. And if you are a person who is actively involved in building make a tronic systems you have to know this philosophy or interested in getting involved. And lastly if you are an instructor in a college because you have a an unwritten job of training the next generation of students with necessary tools to deal with the world that they will see I think this is a requisite for a program that is out there today ok. So for all these three categories of people this is important ok. Inbuilt safety is there, do you have such type of inbuilt safety suppose in the in operation if there is a failure of the system? This is a question that everybody asks ok I am I am I suppose that you are referring to steer by wire have you ever taken a plane aircraft you know ok so what happens in a flight is that everything is by wire ok. The faith that the plane flies you know you are not exposed to this because nobody tells you it is by wire ok. The reason the plane flies today is the actuators are all controlled by wire or the way it flies the way it flies today is by wire it was not like that in the early 40s 50s. The same issues happen there you know the same question of safety comes in there ok. The aircraft industry has had the opportunity to develop the solution over a period of time ok 20, 30 years and also they have the advantage of putting redundant actuators something fails and you have some something else to take care of ok. So, your question is very valid in the automotive industry you will need some time for maturing this technology there is no steer by wire vehicle on the road today no steer by wire car ok and the issue of safety and providing redundancy is a genuine concern in fact that is the most important concern why this technology has not yet come out of the road. But it is going to be resolved soon sooner or later ok another 5, 10 years I think you will see some higher end cars having steer by wire technology, but it is a genuine concern, but the answer that I have always is that of the plane you do not question whether the plane is safe ok. If you look at statistics air travel is one of the safest means of travel ok. The fact that if something goes wrong everybody dies is the only deterrent, but if you just look at number of air crashes in a year to the number of hours flown it is much safer than walking on Mumbai roads ok. So, that has been made possible I mean steer by wire technology works there. So, if you put in the requisite effort it should work here also that is my answer, but there are lot of inputs that are required for that to happen first of all unlimited money that went into the aircraft industry is not there here. So, there are several concerns, but that is a genuine concern for steer by wire. So, what happens is that you will lag say when you want to make a sharp turn it is possible in vehicle when we doubt about the time the lag involved basically face difference between your turning of the vehicle what is that turning on the vehicle. So, just time we have turning mechanical doubts nothing else, when particularly you are handling a bad road or very large water or what not then the failure may a chances of failure as well as the power back required because this wireless system is needed a constant source of electrical power if it fails then we have again a requirement of redundancy there that makes system very complicated that is what we presume. No, no the presumptions are wrong the first of all the analogy with an aircraft, aircraft is not doing some it is not static it is doing lots of things that you do not know about that is how well it is designed ok. In fact, the pilot is not flying it for most of the time except for landing and takeoff right and if you look at the surface envelopes on the side they are doing lots of things when you are flying the aircraft and about different conditions etcetera I think it is more severe in the case of the aircraft industry they go from 0s mean sea level right up to 40,000 feet air is rarefied to about 0.4 0.5 times what it is here. So, they are constantly doing this day in and day out they can fly through thunderstorms they can land in all sorts of weather. So, I mean I think there is no comparison between the complexity there and here but at the same time the main issue here is to be able to realize a by by a solution which is cost effective you know you do not have the flexibility in an automobile to put all sorts of redundancy that you would want in place. So, the main challenge is actually cost effectiveness it is not so much whether it can it can navigate about the electric power pack failing I mean it is again is a question of reliability. So, have you encountered a vehicle a car today that fails because there is no no fuel going into it the number of such occurrences actually is far lesser than what it used to be earlier these are all fuel injected cars and they are all driven by electric power packs in some sense. So, just because it is electrical it does not mean that it is less less reliable. It all depends on the on the design of the of the system itself and just because it is it is mechanical also it does not mean that it is bad. So, you will need to judiciously use both of these things. So, you know lambasting one set of technology tools over the other is does not make sense I mean it depends on what you are what you are trying to do. You know, but certainly the notion that electrical systems are are less reliable than mechanical systems is not true. So, that is one thing that possibly you need to get out of just because the mechanical system is big it does not mean it will be robust and you know take care of take care of eventualities. I am not implemented anything commercially, but the process is on both these vehicles are running first of all. See none of this stuff can be done without the industry being involved. So, I will just say that a company has been floated to take this into into commercialization ok, but this question of research idea is getting into the into commercial utility this has been on for ages including the rest what happens in the rest it does not mean that anything that happens in the lab goes out into the market ok wait one let me finish ok. Besides that I think that that kind of details is this discussion on on mechatronics itself. So, if you are interested in having a having a chat on whether this is going to get commercialized or not you talk to the guy behind sitting behind you or you can come and talk to me some sometime else ok.