I'm going to present to do research that we have been doing in labor for the last two years but I'm going to show you a little bit also. I have been doing. Before I came here to Georgia Tech before I joined Georgia Tech. So robotics is part and in particular. Control is very hard and it's very hard because. We have to work with systems. For which there's a lot of I certainly don't know the dynamics very well there is very often I said to be about the task we don't have any good models about in the actions of the rest of the world so that's one of the enemies that we have to fight against this enemy then of course there's a lot of complexity in these robots so you have a good morning there they nomics. You have made you think there's a free don't you have. Contact you have and that actuation. And in many cases you have many many many parameters with respect to which you want to optimize So there's a show so also. And not to mention the perception of sight which is I think an extremely difficult problem. So my. Days may be one of the ways to deal with I said the complexity. The idea of learning a control policy. So I have been thinking quite a lot about flight and I have been asking my students and some other people because I think that's a slight. If you don't understand. Anything from this presentation I think if if you guys have in your mind the. I would be very happy so. Let's say we have two axis and then in one axis we will put Hamas' knowledge that we have about. Our system. Reporting System. So we have low to. High in all it's. A very accurate model is a model that requires a lot of knowledge. And then on the. On the X. axis we have essentially. How many interactions we need if any with a real actual system in order to be able to. Perform a task and learning piece dynamics it's just the subcase of performing the task so in the case of that action which means that you are basically you have a very Yet yet we have a very good model so you don't have to really you know you can solve the problem of flying you have a very interesting way to solve this problem and so if you were to place for example traditional money out of control theory. Where you would put it on this diagram. You will put it most likely in the case where you have very high knowledge about your dynamics and if you know they will in the environment very well then you can solve. Everything. Offline right. But then as you start incorporating uncertainty I have any into that world or the dynamics then you start you have to be able to use some other tools. As ation said model predictive control. And then at the end of the bee you can use also reinforcement learning so when I refer to reinforcement living here I mean essentially the classifier going to be seen with you but I meant it as your policy and you have to learn this policy through interactions with actual system so. X. axis here is the axis of interactions but essentially if you need a lot of interactions with the actual de nomics then your time scale of learning is slow because you have to just interact with the system if you don't have to interact with the system and you have perfect knowledge then if you sold everything off line and then you hope that. You have is going to be able to perform the task bar on the real system but then as you add a little bit uncertainty into the problem then you can do predictive control which is essentially you don't interact you don't have to interact with the whole trajectory you just interact for a few time steps and then you'll be optimizing your Paulist. OK so what I'm going to present to days essentially. It is essentially on a trajectory that starts from the control theory to what the protective control today unfortunately I mean and I'm going to present the one frame more that captures all of these cases and of course what is the ultimate goal what is the ultimate goal you want to be able to push. This frameworks to scores as possible to low. Model knowledge and very fast optimization right you want to be able to learn policies with a small information as possible with a few interactions as possible with every other actual There nomics. And as fast as possible. So typically in optimal control there are these two people or so vocal control theory. And that has been a lot of work. This work has motivated pretty much from their AC in. Aerospace. And they need to explore space so often control was really a very hot area at forty S. and fifty's and we have these two gentlemen to put a gag in and the sort of Belmont who actually developed tools to perform to solve difficult control. Problems. But now what what I'm going to present today's essentially non-classical view and non-classical view doesn't mean that this view is not all that because it does we lie on principles that go many years back. But it is non-classical because it brings different flavors together. Especially being some concepts from a statistical physics. We have to rely on my super learning because my SO many will do the job for us to learn they now mix. And of course control theory but I lay zation will be important because as we will see we can solve hard control problems with sampling sampling is something that you can part analyze very nicely and it's a big deal. So. Going to go through my presentation is essentially I'm going to go to different areas for peak ation from robotics to Aerospace Systems and if we have time to condition you to science and essentially I'm going to show how. What of a few research the cast of mind control and harvest use are play to specific tasks and applications in these three domains also another characteristic of my presentation is going to be that it's going to be a theory and it's going to be demos and videos. What everybody's excited and then go back to theory and then again back to demos OK so there is no free lance I mean there is free lance but. We have to assess. We have to understand and I'll try to do my best to explain to you what is the weather the underlying. Principles of the I'm going to I'm presenting today. And so. When you open a textbook in my control theory you see. Equations that consist of a cost function that you want to be able to optimize and this cost function has a cost and it has if you have a time where I was in from the end and you want to be able to optimize. Cost function. And the decision time you have. You are you are you are constraint on a classic dynamical system on a system that has state X. It has you control and it has some noise. And so in one of the previous lights I saw one or. More control theory one was Belmont So let's go with the bowman. With the bellman principle and so what the bellman principle say is that if you want to be able to find a costly state. Then say I want to go to the exit then what they should do is I should be able to find out. My cost to go to the to the next state and from that I'm going to add the cost to go to the target state so I have many possibilities I'm going to pick the one that has a minimal total cost and that will give me a sense of control for the state I am right now. Now this is an equation in words that computer scientists love and so if we go into a very simple example with an example where you have to go from the start say to. What you're going to do. If you're going to split this example in two stages so you want to you will try to solve this problem in stages so the task is to go from the start stay to the goal state the dynamics of a trivial in the end to control tasks are very cleaver just choosing with state to go. So what you will do is you're going to start from there from that goal and you're going to find at this stage just before that goal how much is your value function how costly is essentially to go from the state of estate from state aid to state nine. And now you're going to. Repeat this process for four for states for so now you know how much is that I mean cost to go from state for state six seven eight and you know how much was the cost to go from six states six seven eight to the GO state so then you can essentially find what is the optimal action to take because you can just compare this cost and realize that well if you if I go to state seven that this action to take it has a minimum cost. And at the same time you can find how costly is state for so you are repeating this process. Until you go to the starting state and then you have a path that will take you from the start state to the ghosting So there are few characteristics here in the in the dynamic programming Cristobal in these very toy example that essentially it is a backward process right we started from the go and we back probably gate be a function and then if we do that for every possible state then we should be able to know what is there of low control of course here we are shown that we know the nomics very well they're going to study nothing changes. And so. Is that imagine that you want to do that for the money to be later. In the states place that that's really bad so this is one of the main issues seen. Then I mean programming place well it is because of Amish novelty and so there has been a lot of work in terms of how to do that because of the Amish. Now this is a nice graph and people who do work on on. The have discrete states in discrete actions are very they can understand this graph but the piƱata space. We like to work to work with P.D.S. So we have to compromise here between the computer science point of view and the aerospace point of view and I think both of them are exceedingly important. So if we go to their world of space engineering or to let it go in generating audience or not to control theory all of this operation of backward getting the value function He's described by a partial differential equation this equation is like it wave equation so these various estimates by put it propagated. From the start state to the goal state this is it by quick question before a celebration and a lot of work and there's a lot of work in. Control and the main issue is how do we solve this part of the first an equation. So right so let us assume that we know how to solve is then your optimal control of the social you're going to be in the negative direction of the gradient of the value function so what this is really mean it means that the controller suited for the day and I'm still what's areas of the state space where the value function is small so if you end up being on the target divine a function on the ticket is going to be very small so you go negative that action of the gradient of of the valley function if you knew that one function. So what has happened the last ten years is that there has been a work by a cup and. In terms of trying to see B five especially for celebration that was about two two thousand five. Burt wrote a very nice paper in the Journal of statistical mechanics try to explain how these special differential equations can be actually simply fight and if you can simplify them then you can solve them with something and since sampling is something that we can do very nicely then that's a nice way to solve this of control problems. So what what he did is that essentially he said well let me explain I see this value function so now we have this side which is the ability function and now let me let let us get a let us make an assumption between control of the noise these are essentially the weight in your control court is very low then your control is very chip is R. is very high then your control is very expensive and so what this B.B. transposes is essentially how strong your. Stochastic am seventy S. OK so what these assumptions is that if you have very strong stochastic uncertainty then you should be able to have a lot of control of O.T. which means that your are actually has to be low. And so then. It turns out that when you do these exponential because formation and you make this assumption of end up with. A lot of question of the spot in the French immigration this is called In physics the good of P. deal for the bulk of for complex question it doesn't matter the name. Very important thing is that you can solve this partial differential equation efficiently. And so in that paper he actually had a way to find the solution obvious bias in the first question which means find the size and so that this site has a form of indigo Alright so that was essentially the key paper. So then when I was a P.S. The student like you and I was in the second year of my of I was actually doing my masters before. I was very much interested to control so I had I read all of these papers and then. Moved to U.C. and I worked with the fun I realized that there is in fact a field theory that I Laus you to solve this problem differential. Equations and this theorem is actually very general is very broad it can be used in any for many classes of partial differential. Equations and it has the name of two very important people most of you know it's hard to find one right. Physicist. But there was this other gentleman there Mark Katz was an upright mathematician he was at U.S.C. And so what this If so-called family cuts him I would still say you. Give these parts of the financial equation I can. Express this side as an expectation over a course and then I will evaluate this expectation if I sample from just a class differential equation. So now all the problem of solving this partial differential equation has become a sampling problem so if I have enough competition power to sample. Then I should be able to solve this partial differential equation I should be able to know and then I will know if I will function and then from that I can get my control. So if I want to express the use of a control of as a function of divide we find of. What you will see is happening is that these you use in the positive direction of this means that sysinstall plays a role of these are pretty state has a very. Light very low cost you should be. More desirable so the controller should push me with their actions off more desirable States All right this is what this mathematical expression means communities that I believe it's good to go to the states. And so then I start working on this topic and. My work here was to develop scalable I'll go to this because there are many problems that actually. Emerge from this sampling techniques and so. The intuition here is if you want to go from a start state to state what if what happens after you do a lot of. The sample trajectories you out of. This particular state you evaluate the cost for each one of its trajectory since you have sampled these trajectories you have used noice writer whose ignore sample distance record and then I will keep the profile of the of the. Of the noise for the first time instant and then they are controlled the optimal path of our control will appear to be an average in between all of this noise profiles and the advertising will be excessively given by this probability P.P.I. woodstoves you the noise profiles of that result in trajectories with low cost should actually play a more important role on my control police. Well that is nice in theory when you drive it but when you implement it there are some bad news the bad news is that you have to sample from day nomics and sometime in the theory say that kept the sample from uncontrolled a number. And so why this is a bad idea this is a bad idea because some control dynamics are typically not stable. Also it's bad because it's not safe when you want to really apply this for. All systems to work with the uncle told a nomics. It's not scalable because many times you get that secularists in parts of the state space that are not. Interesting for the task so you have to be able to steer to go to victories in parts of the States plays that are relevant to your task. And it's not medically efficient because well what happens is that you have the six exponentiation when you get to the sectors that are very far from your target and you explain the CA you find of course you have a very high cost you explicitly get bunch of zeros. Right so there's no medical explanation this explanation is a very it's. Going to shrink. Values that psych intake from. Zero to blast infinity to zero and one so explanation is a very hard way to go operation so then what do we do well what do we do next we do import our sampling so we are going to use. Has been used quite a lot in particularly and so. Using this. Idea. Of. That will that will steer the third sector is in a terribly of way towards parts of the state space that they're really one with respect to our task and then they will optimize these threats activities so how do we do import our sampling well with. That given by the first expression which means your sample from the out of control dynamics but now I want to be able to sample from the control dynamics so I have these two equations and I want to make them to be equal. So how do I make them to be equal that's the idea of input and sampling by essentially incorporating these weight here with us. I can't open a book is to cross the country list if I have ever had the opportunity to take a class just across the country list and I open a book and I go and I look for the important sampling and I may see the name rather than the Couldn't that have a thief or a little more likelihood ratio in this of a nice photo which I can get and I can very nicely evaluate So this new term will actually result in. Getting a. Therapy scheme in which I can essentially update my controls I can generate the sectaries I can have the security of scheme I can start with. Control Policy and I can improve this control policy and the result of these imports are something is that I'm going to end up essentially with some court action in the course function. So. That was pretty much when I was the first year of my post oak. So then I put everything down and I have this diagram here to show you that what we did so far is we start with a nomic programming principle we did have become an equation we did the explanation for this formation we got this very nice simple partial differential equation for when we apply the time and. Then we have a solution for our problem. And then we have to do important sampling. So this is the load diagram of our reasoning OK so if we did if we did not know statistically this or or suppressing or. We are not so much interest about this theory maybe Graham you may want to have in your mind. But it turns out that as typically happens when you study and when you do. That there is a whole world world out there that you may. Not be familiar so your continued You are living right you're learning is. A lifelong experience so. There was an alternative view and I was there on the view of all of this framework which actually resulted in some very massive results that we have right now on our project and so I'm going to very quickly go into this framework it involves a little bit of physics but essentially what's going to happen is that I am not going to I'm not going to talk about peace anymore I'm not going to talk about of the multi principles I'm going to start with two very important concepts and they're very important relationship between these two concepts I'm going to start from the course of of the free energy which is typically it has this for. Big concept of generalize entropy you can think about it in a less entropy as they could but Labor Day version is between probability Q. and Pete so there's a very interesting information between these two. Functions or quantities with this is actually described by the third of the equation on my slight which if I wanted to write it in words it says that the free energy is actually work. Or Times journalists Enderby So this is a relationship that you find in thermodynamics OK so. And also what you can get from this. Inequality here is that you can optimize their right hand side though they make one E.G. with respect to Q You can find out what is a probably distribution and you have a way to find that any tennis out that is given by this expression which is a very known exponential function and we see that quite a. A lot in many applications seems that this calmness and learning. So now let's go back today and I'm going systems. I will take exactly the same inequality and I'm going to assign you to this to suppress the person into P. and Q.. Sample trajectories generated by they numbers that are I'm control and they nomics that are. Controlled so any sample right now in these probability space he's. OK And now again I'm going to open my favorite book. And I can show that if I take this inequality where essentially what's going to happen is that I will end up with a find them indication. You see that you have an expectation over the course function of state and you have a control cost of value it is for Over time what is' so that is a course that we typically optimizing is the across the of the control theory. So it them sout that. Actually becomes survival function and in fact it satisfies a come to circle the well known equation so that was that really blew my mind because I did not have to go to any argument to feel you know dynamic programming not going to be I can mix one principle all that I have to do is apply some very simple. Gensis inequality and again use these other magazine David if and I end up with an expression that looks like the classic optimal control. So. There is this other view of control control theory which is very provocative because essentially the nation of this framework is to do that I become the circle Boman equation and the other case you start with the NOMIC programming principle. So. So when I when I came here. And I met a couple of students and we put a lap together. Thinking a little bit more provocative about stochastic optimal control and what we said and this is primarily the work by. Grady Williams is that since we have this optimal probability the measure what does it really mean it means that if I had the optimal controller and I was plugging it into my day nomics and I was something physically the probability distribution over the starts activity should be given by this expression. OK So Miles if we are half what the third sector should look like if they nomics are optimally controlled so then you stand off working with P.V.C. The stench of going through there comes a circle people an equation how about I try to minimize what I'm going to base my controller in some way and I put them in that I. Was between the optimal to which I have it and actually big Q Which I can but I'm there but I'm at the base by an actual controller. So you can do that and after some. Analysis. Essentially you can show that you can still get it but I think in the GO controller but this time what happens is that you don't have to work with P.D.S. anymore of course if you want to make a connection with traditional look to my little bit of additional sense of commodity namely to put the I can back and in particular come to an equation you have to work with these. But that is only in the case where you want to make a connection with the principles the second benefit you have is that there is no I mean assumption right now between control authority no. Yes you don't have to make this assumption anymore and also the third point is that he generalizes to any kind of the classic disturbances you can have stochastic disturbances for which you don't have actually only Goetia annoyance you can have blush on lines you can have actually also struck us think. You can have. They now mix that but none are fine in controls meaning that their control doesn't up at Lena only in your dynamics so that's a very elegant framework because she please very general it comes from a simple post relates it relates to the addition of up to my lady but you can go beyond. The mouth and so this is. What we have been doing of course. At the end of the day we will have to use important sampling and there are many important steps important in. There are many things any important something which I'm skipping right now but I'm happy to discuss this offline but essentially we apply this framework in a receiving origin fashion on an actual system and that's the system that of the of there are. So this is I think one day in September it was before the ACA. And I believe it was the first week of September and this is the third of experiment of that day. So. This is the performance. That you could get the task here is you want to go as fast as possible around the track you are you optimizing essentially you are sampling trajectories every sixty hertz. OK. You have a model. Modem essentially that we call you find it is we have. You drive a car and you collect data and you feet a. Differential Equation I have to say here that this is a collaborative work this is a work that is coming from Grady ball and Brian I believe everybody knows full and Brian. They have been working very hard on this project now it turns out that this is with offline learn dynamics. Now this is another video what do you show what is really happening as this system sample subjectivities and finds the local control appliance control in recent years OK So there's another to do what do you see what happens with the actual system and then what happens with the. With IT sector OK. OK so now that there was a system and that if you Keisha right you have to learn the dynamics of flight and so we use just. Begun to Gratian one of the simplest things that you can do to learn the dynamics but then. Ball and cry and we're very curious and then they thought about pushing really the performance of the vehicle and instead of just doing offline learning how about we actually learn the dynamics online so we started with a model that may not be very high curated But now we are going to learn the dynamics in an online fashion by just doing the regard to be squares that's the thing that everybody learns on a in a much unique class that's the first one of the first creation our dreams to use Garson function so if you do that then it turns out that you can go a little bit faster so this is the. The view from the. From the government I was. On board. And then we saw another video where you can see some. Aggressive maneuvers. Now there are successes and failures in many roads or in the report it's right so these are some cases where this isn't going to recover. But of course there are cases in which this is them cannot recover right and there are two three different reasons why that may happen first of all the sensing here right very sensing involved and we use a G.P.S. sensor and sometimes you can lose the G.P.S.. Signal also the second reason is that sometimes the car becomes overconfident it believes that the modem is very accurate but it's actually not OK And I think the reason is that this is actual little books. Sometime. Things do not work and of course you want to be able to prove. Your I would I'm sure that you can get consistency in your. Experiments but we believe that the key here for making these to be. To improve our work is that we want to be able to have better ways of learning things. And this is what we are doing actually right. Now it turns out that you can get the same framework. You can get the same framework and you can actually. It has some nice properties about allow you to work with. For the case where you have multiple vehicles right so now here in this particular case the task is to go through the forest you have you have all of the obstacles that are moving and that the task is they have to go through the forest and they have to stay in close proximity. So we have here we have nine dollars with sixteen states each so the total is one for the four states. Now there are of course traditional methods into a sector of musicians such as the finance and then I mean program how many of you know the financial And I mean programming. Everybody should know the financial dynamic programming OK because there are many papers in robotics and control on different programming or they go back fifty years so if you compared this method was differential then I mean programming what happens is that. You can go faster if you have a task of course going through the forest with just a single. And you can be more risk seeking meaning you can go closer. Two obstacles and that is because when you have to evaluate your cost you don't take any of this so you it is OK for you to have course that sometimes maybe actually discontinues so with sampling you're really exploiting that opportunity that. Capability. And this is another plot what happens if you have nine whether And. What happens with a complex and saw so far is so some are going to operate in this fashion you sample you if you actually sample do you act but it turns out that you can actually use the framework if you want to be able to do reinforcement All right so this is work that they did before I joined. Georgia Tech and essentially you can do something like a gradient and you can use exactly the same exact same frame. And I have few videos here. But I think I'm going to skip these videos because I think that the collective go to the second part of my talk which is. Essentially the work that we have been doing together with my collaborator in aerospace engineering. Cerberus we have been in the surf and I. Proposal Grant and the task there is for us to be able to. Come up with. New audience for the executive that actually take into account the assets that you have in your sensors and seventy you have in your day nomics right now that's going to be more more more clear but the questions that we're asking is how do we get uncertainty if we have to cross today nomics how do. You want to push it to believe States and then. One of the interesting questions is that if you want to. Do. Believe space that's a maze ation what's really the proper representation right you can start with mean environments you can actually go to the case where you don't have a day nomics you don't have a model of the day none exist to work with in violence but you can actually take a completely different point of view where you want to just go and sample. Control the whole sample of trajectories So since you guys don't know the D.P. let me give you a sort of overview of the financial economic program and. The financial And I mean programming again if you want to go from a start say to go state and what we will do is we're going to start with any missile policy we get a trajectory now everybody likes to work with the systems right because we have a team as results and everybody likes to work with complex functions with quadratic functions because we know how to optimize them so what do we do we are going to approximate our knowing that they not only out along that sector and take what I think expressions of the cost function along the same to exactly. Right and then we will provide gate value function which is really essentially a plank but then I make. Programming on the subject. And I said we do that we have a way to find how we should update our policy so that we. Overall cost then we update our policy which anything you do and security and we repeat the same process until we essentially converts which means that we don't have any improvement in our cost Now this is a method of that requires doing that over the enemies and quadratic up looks mation of the cost function and is the method that we're going to be using. Here So how do we provide gait and how do we even have eyes then I am well we have been doing some work here. In the craters it is essentially a way to manage your dynamics properly sure that. When you lean on as your dynamics. Is not sensitive to your disk they station step So what happens essentially is that you guys are familiar with it. Or your scheme so this is the first two graphs on the left is the case of a double car pool would just pick one of the states and want to go to from a starting state to is zero state so you have. Three lines with different colors that correspond to different sedation steps and you see how the solution. Actually changed in the first row as you change your disk with a station step on K. and see what happens when you use this took us about a shell of what we have developed you see that there is actually some months sensitivity in your actual solution so there's still classified to create a easily is less sensitive and he that allows you to perform particular maceration for a long time what is'. He then saw that there are any implications of the. Integrator in status to mation because where else do we have as they now mix if we want to do status the Mission X. and they come off leaving so now let's So what what happens there so here what we have is that we have the violence that grows and then whenever we see divide it has to drop that means that we have an update of them so divided should drop right and so what we have on the on the on the left side is their oil or scheme and what we have on their right side is. He. Uses progressive ideational in the greater So what happens here is that you have their add in the blue and red color corresponds to their larger disk with a stations that you see as unique because it's going to. Come with intercessory brakes OK you have this red line here so there are many implications of across the body in the goodness of maize ation and state is the nation and we have a couple of papers that have been accepted that if you are right now and we are going to continue on this work because we believe that this is extremely important now we go to the second question which is how do you probe i Gate they believe they know so now we go from just propagating just wants to cross the threshold of question why did they believe they now mix if we want to include the state they. And also what happens if we don't know that they not mix so what happens here is that it is they want by. You paying. Is that we are going to use a go some process to be presented a nomics and to propagate the day nomics So let's say that you have some useful data from an experiment you can use a go some process to learn today nomics and then based on these go shower process you can probably gate the meaning of it of audience so now instead of having Now I have these. Two equations for the predictive mean and the predictive of audience and now I can take the tools that the additional tools I have from of my control theory such as the first and then I mean programming and apply them on these a presentation. So I'm going to so the goal is to steer the mean end of audience also this framework allows you to put a photo of simulation since you have also on your state you can actually see in which case is unified. Yes that means that the optimizer has brought the go shop process of the presentation far from the initial data so then you can go back to the system any and you can query wanted exactly you get the you to update your gushing press the presentation and then you continue your of. So you want to be able to minimize interactions with serial hardware are smaller. As. Many mice as more as possible so it turns out this is State of the art math which is called people go and I think that many people are familiar with with with Bill go is the first method that actually. Really reduce the number of sample trajectories that you have to play on actual system if you want to run a police. All right so that was a very big contribution and it's still one of the state of the art. Methods so we compared these methods with our methods with which is to use a go someplace that a position of the nomics and perform particular plays a shot using the D.P. and what you see we have two tasks. Are you you see here that in terms of number of the directions with the actual dynamics. We are compatible to go but in terms of time for the let's say for the case of. Cardboard you need up to twenty two twenty three hours to find the good policy with people go wild with our math of unit twenty five minutes so we have comparable sample efficiency with people go we can still not go but we are we can find actually policies much faster than people. And then. That that was actually a pair and then what your bank did was to actually get this Gaussian processor presentation use them in their. Back in the GO control framework and it turns out that we can get very good results with this approach as well and that resulted in another it's paper. And of course you want to be you want to be you want to be able to push the frontiers of Fiore and compute ation which means that you want to be able to work with a whole ensemble of the sectors so no mean nobody wants us work with a whole ensemble So it turns out that. This is something that you can do but it is very expensive. Down to it boils down to a stand of controlling right now it's just a single ordinary for some equation just controlling a partial differential equation that tells me how the probability distribution changes over time. This it works that my student by actually doing and we have few papers that absent made it since this is recorded I'm not going to give more details about that but I think that there's a lot of future towards really pushing the envelope in terms of actual theory mathematical theory sampling and but I lays ation which can be result from these frameworks. And so advanced. There are we have we also like neuroscience We also like biomimetic by only metric. Robotics this is work that I did using my post look but here. At Georgia Tech actually we have been working in collaborating with. A black. And white university and since we have all of his albums and we can. Reject of musician and sample based control how about try to actually control a. Neural system. And we have some very very very preliminary. Results. So what is next. So we have these two universe that was my world these two universe one is optimal control theory the other is that this cause physics and in the same that all of this after I think fifty forty years of research I think we have a good understanding right now of what is the overlapping and I say that because. There are many communities involved and people use different I mean all of the many times and different concepts. And sometimes his fav difficult to bring all of these people together into a consensus of what we know and then what is the next step to do because if you don't know what what what what what has been done then how do you know what what is the process the progress that we should make anyone with their action so we have to bring all of these people together to talk about these things. And so I think that we agree that at the center of this. Connection is these very fundamentally Mother Counts from these two very important people find my own cats this is that even if I'm in a cat's Lima. But guess what there are extensions of it that can go to the fully known American base meaning that I don't have to actually perform any transformations maybe a little bit of one of the price on the sampling site and in fact you can go beyond that you can actually talk about partially over several systems in which right now you have to do with this piece in terms of people or is this. So this is where the future from my point of view a lot of these I'll go to that will be will be developed are something based so there is a lot of future in terms of how do we bring this I'm going seeing to it but the good. Hardware. And we thought this is the last flight the people that have influenced my way of thinking by reading their work. I would like to. Thank my students very much I have very serious students and I have to sometimes be funny so starting from bank from the left he's worth is different people will believe stick. To. A fan who likes one stuff. Too. David who works on the late system since I took my ization. To grade his work is definitely he's world is different in the bottom. To do all the routes. George then. Get out the dilatory who graduated I was quite amazing him together with Eric Johnson and. Yes. Except Bush and devising him to give it with one and showed us we have one leading our lab. And then my nan and of course our collaborators here at Georgia Tech and our sponsors thank you so much. For the questions. Yes. So. I think you can get a lot of in from the information about this question for for my students who are happened to sitting in. Your table but I can tell you essentially that there was a model with certain features and then we picked by amateurs on that model in a way that the BUT I'M A disappeared female. In the model so the model is not only in the state but the but I'm of the supreme army so that we can go for the Gratian. OK but now there's a lot of ongoing work in terms of how to learn the dynamics and Biden is also involved in this and. We have many ideas and there are many undergoing experiments. So there was a missile model and then we picked features from up model it just I didn't find it but I'm with us. Yes. Hyper. Hyper than ever. So. We have not investigated that meaning that we have don't we we have not. We don't have any paper but we have been thinking about that in terms of what happens if you have for example there is a change because you have contacts right. And so I guess in that case you would have to be able to predict where the treaty is going to happen between this a dynamic say dynamics B. and then. Do that in a preschool way. So yeah this is something that you know it's it's on the pipeline. And the other question. You can ask me any question any question. You understand enough the question is if you are a kid if you have kids your city that's a must but that we just became. Yes. We have a driver here and I think. That's. What do what do I stand. For Ok so yeah. I think we are I think they're very. Receptive you know it's just I think a mother of. Everybody I got them out wants to be smart right and he wants to make two published papers so I would say I would classify I would answer your question by saying that I would classify people in two main classes. Classes. People who want to know what has been done and then move forward and people who just don't care. And maybe sometimes you know this is also very productive because you end up with having a different interpretation maybe south in a different point of view. I'm not. In a negative way but I believe. It is important to know what has been done so that we know how much we have made progress in the last fifty years or. So but I believe the job of the communities is poverty the communities. To discuss. And especially the robotics community I think that there are bodies community has many advantages in terms of other communities because. I will just remember that there is a video with it's our family who say it doesn't matter how good would your theory is doesn't matter how smart you are if it doesn't. Validate experiment it's just wrong so robotics really brings this very nice combination of. The ability to work with theory but also test it on a real actual system and in that sense I think that it is very scientific it has become very scientific. So I believe that robotics is a good place to be even if you want to be like a hardcore scientist. If you want yeah if you want to make an impact at the end of the day you want to be able to apply and then you want to be able to have other people using your work so about having other people using your I'm going to do your work. So I think robotics is really placed in a very very good position. You can make a lot of progress in terms of either. You know question. OK thank you so much.