Robert Playter: Boston Dynamics CEO on Humanoid and Legged Robotics | Lex Fridman Podcast #374

1. 0:00 – 2:57

   Introduction

   1. RPRobert Playter0:00

      And so our goal was a natural-looking gait. It was real- it was surprisingly hard to get that to work. Um, and we, but we did build a- an early machine. Uh, we called it Petman Prototype. It was the prototype before the Petman robot.

   2. LFLex Fridman0:15

      Mm-hmm.

   3. RPRobert Playter0:16

      And it had a really nice-looking, um, gait where, you know, it would stick the leg out. It would do heel strike first-

   4. LFLex Fridman0:24

      Mm-hmm.

   5. RPRobert Playter0:24

      ... before it rolled onto the toe, so you didn't land with a flat foot. You extended your leg a little bit. Um, but even then, it was hard to get the robot to walk where it wou- when you're walking, that it fully extended its leg. And getting that all to work well took such a long time. In fact, I, I probably didn't really see the nice natural walking that I expected out of our humanoids until maybe last year. And the team was developing on our newer generation of Atlas, you know, some new techniques, um, uh, for developing a walking control algorithm. And they got that natural-looking motion as sort of a byproduct of a, of a just a different process they were applying to developing the control. So that probably took 15 years, uh, 10 to 15 years to sort of get that from, from, you know, the Petman Prototype was probably in 2008 and what was it? 2022. (laughs) Last year that I think I saw good walking on Atlas.

   6. LFLex Fridman1:27

      The following is a conversation with Robert Playter, CEO of Boston Dynamics, a legendary robotics company that over 30 years has created some of the most elegant, dextrous and simply amazing robots ever built, including the humanoid robot Atlas and the robot dog Spot, one or both of whom you've probably seen on the internet either dancing, doing back flips, opening doors, or, uh, throwing around heavy objects. Robert has led both the development of Boston Dynamics' humanoid robots and their physics-based simulation software. He has been with the company from the very beginning, including its roots at MIT, where he received his PhD in aeronautical engineering. This was in 1994. At the legendary MIT Leg Lab, he wrote his PhD thesis on robot gymnastics. As part of which, he programmed a bipedal robot to do the world's first 3D robotic somersault. Robert is a great engineer, roboticist and leader. And Boston Dynamics, to me, as a roboticist, is a truly inspiring company. This conversation was a big honor and pleasure, and I hope to do a lot of great work with these robots in the years to come. This is the Lex Fridman podcast. To support it, please check out our sponsors in the description. And now, dear friends, here's Robert Playter.

2. 2:57 – 11:18

   Early days of Boston Dynamics

   1. LFLex Fridman2:57

      When did you first fall in love with robotics? (laughs) Let's start with love and robots.

   2. RPRobert Playter3:04

      Well, love is, is relevant because I think the, the fascination, the deep fascination is really about movement. And, uh, I was visiting MIT looking for a place to get a PhD, and I wanted to do some laboratory work. And, uh, one of my professors at, in the aero department said, "Go see this guy, Marc Raibert, down in the basement of the AI Lab." And so I walked down there and saw him. He showed me his robots, and he showed me this robot doing a somersault.

   3. LFLex Fridman3:37

      (laughs)

   4. RPRobert Playter3:37

      And I just immediately went, "Whoa!" You know?

   5. LFLex Fridman3:40

      Yeah.

   6. RPRobert Playter3:40

      "Robots can do that?" And because of my own interest in, in gymnastics, there was, like this immediate connection. And, um, you know, I was interested in, I was in an a- aero-astro degree because of, you know, flight and movement was all so fascinating to me. And then it turned out that, you know, robotics had this big challenge. How do you, how do you balance? Uh, how do you, how do you build a legged robot that can really get around and that just, that was a fascination. And it still exists today. You're still working on perfecting motion in robots.

   7. LFLex Fridman4:13

      What about the elegance and the beauty of the movement itself? Is, is there something maybe grounded in your appreciation of, uh, movement from your gymnastics days? Did you... (sighs) Was there something you just fundamentally appreciated about the elegance and beauty of movement?

   8. RPRobert Playter4:31

      You know, we had this concept in, in gymnastics of, um, letting your body do what it wanted to do. When you get really good at gymnastics, um, part of what you're doing is putting your, your body into a position where the physics and the body's inertia and momentum will kind of push you in the right direction in a very natural and organic way. And the thing that Marc was doing, you know, in the, um, basement of that laboratory, was trying to figure out how to build machines to take advantage of those ideas. How do you build something so that the physics of the machine just kind of inherently wants to do what it wants to do? And he was building these springy pogo stick type-

   9. LFLex Fridman5:12

      Mm-hmm.

   10. RPRobert Playter5:13

       You know, his first cut at legged locomotion was a pogo stick where it's bouncing and there's a spring mass, uh, system that's oscillating, has its own sort of natural frequency there. And sort of figuring out how to augment those natural physics, um, with also intent. How do you then control that, but not overpower it? It's that coordination that I think creates real potential. We could call it beauty, you know? You could call it, I don't know, synergy?

   11. LFLex Fridman5:41

       Mm-hmm.

   12. RPRobert Playter5:41

       Uh, people have different words for it. Uh, but I think that that was inherent, uh, from the beginning that was clear to me that that, that's part of what Marc was trying to do. He asked me to do that, uh, in my research work. So, um, you know, that's where it got going.

   13. LFLex Fridman5:54

       So part of the thing that I think I'm calling elegance and beauty in this case, which was there even with the pogo stick, is maybe, uh, the, the efficiency. So letting the body do what it wants to do.... trying to discover the efficient movement.

   14. RPRobert Playter6:06

       It's definitely more efficient. It also, um, becomes easier to control in its own way because the, the physics are solving some of the problem itself. It's not like you have to do all this calculation and overpower the physics. The physics naturally, inherently want to do the right thing. Uh, there can even be, you know, uh, feedback mechanisms, stabilizing mechanisms that occur simply by virtue of the physics of the body, and it's, you know, not all, not all in the computer or not even all in your mind as a person. (laughs) And I... There's something interesting in that, that, uh, melding.

   15. LFLex Fridman6:43

       You were with Marc for many, many, many years. You were there in this kind of legendary space, uh, of, uh, Leg Lab at MIT in the, (laughs) in, in the basement.

   16. RPRobert Playter6:53

       (laughs) .

   17. LFLex Fridman6:53

       All great things happen in the basement.

   18. RPRobert Playter6:55

       (laughs) .

   19. LFLex Fridman6:55

       Is there some memories... Uh, is there some memories from that time that you have? Because it's so... It's such cutting-edge work in, in, in robotics and artificial intelligence.

   20. RPRobert Playter7:09

       The memories, the distinctive lessons I would say I, I learned in that, in that time period, and, um, and that I think Marc was a great teacher of, was, uh, it's okay to pursue your interests, your curiosity. Do something because you love it. Um, you'll do it a lot better if you love it.

   21. LFLex Fridman7:30

       Mm-hmm.

   22. RPRobert Playter7:31

       Um, that, that is a, a lasting lesson that I think, uh, we apply at the company still, um, and really is a core value.

   23. LFLex Fridman7:41

       So, the interesting thing is I got to, um, uh, with people like, uh, Ross Tedrake and, uh, and others, like, the students that work at those robotics labs are, like, some of the happiest people I've ever met. I don't know what that is (laughs) . I meet a lot of PhD students. A lot of them are kind of broken by the wear and tear-

   24. RPRobert Playter8:01

       (laughs)

   25. LFLex Fridman8:01

       ... or the process. Uh, but roboticists are... While they work extremely hard and work long hours, there's, um, uh, there's a happiness there. The only other group of people I've met like that are people that skydive a lot (laughs) .

   26. RPRobert Playter8:16

       (laughs) .

   27. LFLex Fridman8:16

       Like for s- for some reason, there's a deep fulfilling happiness, maybe from, like, a long period of struggle to get a thing to work, and it works, and there's a magic to it. I don't know exactly 'cause it's so fundamentally hands-on, and you're bringing a thing to life. I don't know what it is, but they're happy.

   28. RPRobert Playter8:33

       We see... You know, our, our attrition at the company is really low. People come, and they love the pursuit, and I think part of that is that there's perhaps an actual connection to it. It's a little bit easier to connect when you have a robot that's moving around in the world, and part of your goal is to make it move around in the world. You can identify with that. And, and this is on a... This is one of the unique things about the kinds of robots we're building, is this physical interaction lets you perhaps identify with it. So, I think that is a source of happiness. I don't think it's unique to robotics. I think anybody also who is just pursuing something they love, it's easier to work hard at it and be good at it, and, um, uh, m- not everybody gets to find that. Uh, I, I do feel lucky, uh, in that way, and I think, uh, we're lucky as an organization that, that we've been able to build a business around this and that keeps people engaged.

   29. LFLex Fridman9:29

       So, if it's all right, let's linger on Marc for a little bit longer, Marc Raibert. So, he, he's a legend. Uh, he's a legendary engineer and roboticist. What, what have you learned about life about robotics from Marc through all the many years you've worked with him?

   30. RPRobert Playter9:45

       I think the most important lesson, which was, you know, have the courage of your convictions and, and do what you think is interesting. Um, be willing to try to find big, big problems to go after.
3. 11:18 – 15:16

   Simplifying robots

   1. RPRobert Playter11:18

   2. LFLex Fridman11:19

      Um, how, how tough is the job of simplifying a robot?

   3. RPRobert Playter11:22

      So, I, I'd say in the early days, the, the thing that made Boston... The researchers at Boston Dynamics special is that we, we worked on under- figuring out what that, that central principle was and then building software or machines around that principle, and that was not easy, uh, in the early days. And, and it, it took, um, real expertise in understanding the dynamics of motion and feedback control principles, how to build and... You know, with the computers at the time, how to build a feedback control algorithm that was simple enough that it could run in real time at 1,000 hertz and actually get that machine to work. Um, and that was n- not something everybody was doing, you know, at that time.... now, the world's changing now, and I- I- I think the approaches to controlling robots are going to change. Um, but, uh, uh, and they're going to become more broadly, um, available. Um, but at the time, there weren't many groups who could really sort of work at that principled level, uh, with both the software and- and make the hardware work. I'll- and I'll say one other thing about you're sort of talking about what are the special things. The other thing was go- it's o- it's- it's good to break stuff, you know?

   4. LFLex Fridman12:46

      Mm-hmm.

   5. RPRobert Playter12:46

      Um, you know, use the robots, uh, break them, repair them, um, you know, fix and repeat. (laughs) Test, fix, and repeat. And that- and that's also a core principle that has become part of the company, and it lets you be fearless in your work. Too often, if you are working with a very expensive robot, maybe one that you bought from somebody else or that you don't know how to fix, then you treat it with kid gloves, and you can't actually make progress. You have to be able to break something. And so I think that's, uh, been a- a- a principle as well.

   6. LFLex Fridman13:22

      So just to linger on that psychologically. How do you deal with that? 'Cause I remember I had, uh, uh, I built a RC car where it did some, uh, it had some custom stuff like compute on it and all that kind of stuff, cameras, and, uh, because I didn't sleep much, the code I wrote had an issue where it didn't stop the car, and it... The car got confused, and at full speed at like 20, 25 miles an hour slammed into a wall. And I just remember sitting there alone in a deep sadness, um, sort of full of regret, I think, almost anger, um, uh, but also, like, sadness because you think about, "Well, these robots, especially for autonomous vehicles, like, like, you should be taking safety very seriously even in these kinds of things." But just no- no good feelings, um, and made me more afraid probably to do those kind of experiments in the future. Perhaps the right way to have seen that is positively, like is- is to, uh-

   7. RPRobert Playter14:25

      It depends if you could have built that car or- or just gotten another one, right? That would have been the approach. Um, I remember, um, when I got to grad school, um, you know, I got some training about, uh, operating a lathe and a mill up in the machine shop, and I could start to make my own parts, and I remember breaking some piece of equipment in the lab and then realizing 'cause I... Maybe this was a unique part, and I couldn't go buy it, and I realized, "Oh, I can just go make it." That was an enabling feeling.

   8. LFLex Fridman15:02

      Yeah.

   9. RPRobert Playter15:02

      Then you're not afraid. Yeah, it might take time. It might take more work than you thought it was gonna be required to get this thing done, but you can just go make it, and that's freeing in a way that nothing else is.

4. 15:16 – 19:59

   Art and science of robotics

   1. RPRobert Playter15:16

   2. LFLex Fridman15:16

      You mentioned, um, the feedback control, the dynamics. Sorry for the romantic question, but is... In the early days and even now, is the dynamics, probably more appropriate for the early days, is it more art or science?

   3. RPRobert Playter15:33

      There's a lot of science around it, and- and trying to develop, you know, scientific principles that let you extrapolate from, like, one-legged machine to another, you know, develop a core set of principles like- like a spring mass bouncing system, and then figure out how to apply that from a one-legged machine to a two or a four-legged machine. Those principles are really important, and- and- and were definitely a core- a core part of our work. Um, there's also, you know, when we started to pursue humanoid robots, um, there was so much complexity in that machine that, you know, one of the benefits of- of the humanoid form is you have some intuition about how it should look-

   4. LFLex Fridman16:20

      Mm-hmm.

   5. RPRobert Playter16:20

      ... while it's moving, and that's a little bit of an art, I think. Now it's... Or maybe it's just tapping into a knowledge that you have deep in your body and then trying to express that in the machine.

   6. LFLex Fridman16:33

      Yeah.

   7. RPRobert Playter16:33

      But that's an intuition that's a little bit more on the art side. Uh, maybe it- it predates your knowledge, you know? Before you have the knowledge of how to control it, you try to work through the art channel. (laughs)

   8. LFLex Fridman16:43

      Yeah.

   9. RPRobert Playter16:43

      And humanoids sort of make that available to you. If it had been a different shape, maybe you wouldn't have had the same intuition about it.

   10. LFLex Fridman16:50

       Yeah, so your knowledge about moving through the world is not made explicit to you, so you just... That's why it's art, you get to-

   11. RPRobert Playter16:59

       And it might... Yeah, it might be hard to actually articulate exactly, You know? (laughs)

   12. LFLex Fridman17:03

       Yeah.

   13. RPRobert Playter17:03

       There's something about... Um, and- and being a competitive, uh, athlete, there's something about seeing a movement. You know, a coach, one of the greatest strengths a coach has is being able to see, you know, some little change in what the athlete is doing and then being able to articulate that to the athlete, you know? And then maybe even trying to say, "And you should try to feel this." Um, so there's something just in seeing, and again, you know, sometimes it's hard to articulate what it is you're seeing, but there's a just perceiving the motion at- at a rate that is, um, uh, again sometimes hard to put into words.

   14. LFLex Fridman17:41

       Yeah, I- I wonder, uh, how it is possible to achieve sort of truly elegant movement. You have a movie like Ex Machina. I'm not sure if you've seen it, but, uh, the main actress in that who plays the AI robot, I think is a ballerina. I mean, just the natural, um, elegance and the, I don't know, eloquence of movement is, it's... (laughs) It looks efficient and easy and just... It looks right.... it looks beautiful.

   15. RPRobert Playter18:13

       It looks right is sort of the key, yeah.

   16. LFLex Fridman18:15

       And then you, you look at, um, especially early robots, I mean, they, they, they're so cautious in, in the way they move, um, that it's not, it's not the caution that looks wrong. It's, it's something about the movement that looks wrong, that feels like it's very inefficient, unnecessarily so. And it's hard to put that into words exactly.

   17. RPRobert Playter18:38

       We think that... And part of the reason why people are attracted to the machines we build is because the inherent dynamics of movement are m- are closer to right.

   18. LFLex Fridman18:48

       Mm-hmm.

   19. RPRobert Playter18:49

       Um, because we, we try to use, you know, walking gaits, or we build a machine around this gait, where you're trying to work with the dynamics of the machine, instead of to stop them.

   20. LFLex Fridman19:01

       Mm-hmm.

   21. RPRobert Playter19:01

       You know, some of the early walking machines, you know, you're essentially... You're really trying hard to not let them fall over, and so you're always stopping the tipping motion, you know?

   22. LFLex Fridman19:12

       Yeah.

   23. RPRobert Playter19:12

       And sort of the insight of dynamic stability in a legged machine is to go with it, you know? (laughs) Let the tipping happen, you know, let yourself fall, but then catch your, catch yourself-

   24. LFLex Fridman19:23

       Mm-hmm.

   25. RPRobert Playter19:23

       ... with that next foot. And there's something about getting those physics to be expressed in the machine that people interpret as life-like-

   26. LFLex Fridman19:34

       Mm-hmm.

   27. RPRobert Playter19:34

       ... or, or elegant, or just natural looking. And so I think if you get the physics right, it also ends up being more efficient, likely. There's a benefit that it probably ends up being more stable in the long run. You know, it could, it could walk stably over a wider r- range of conditions. Um, and it's, uh, and it's more beautiful and attractive at the same time.

   28. LFLex Fridman19:58

       So,

5. 19:59 – 36:53

   Atlas humanoid robot

   1. LFLex Fridman19:59

      how hard is it to get the humanoid robot Atlas to do some of the things it's recently been doing? Let's forget the flips and all of that. Let's just look at the running. Maybe you can correct me, but there's something about running... I mean, that's not careful at all. That's, you're falling forward. You're jumping forward and are falling, so how h- hard (laughs) is it to get that right?

   2. RPRobert Playter20:20

      Our first humanoid, we needed to deliver natural looking walking. You know, uh, we took a contract, uh, from the Army. They wanted a robot that could, uh, walk naturally. They wanted to put a suit on the robot and be able to test it in a gas e- environment. And so they wanted the na- the, the motion to be natural. Um, and so our goal was a natural looking gait. It was real... It was surprisingly hard to get that to work. Um, and we... But we did build a, an early machine, uh, we called it Petman Prototype. It was the prototype before the Petman robot.

   3. LFLex Fridman20:56

      Mm-hmm.

   4. RPRobert Playter20:57

      And it had a really nice looking, um, gait, where, you know, it would stick the leg out. It would do heel strike first-

   5. LFLex Fridman21:05

      Mm-hmm.

   6. RPRobert Playter21:05

      ... before it rolled onto the toe, so you didn't land with a flat foot. You extended your leg a little bit, um, but even then, it was hard to get the robot to walk where it would when you're walking, that it fully extended its leg, and, and essentially landed on an extended leg. And if you watch closely how you walk, you probably land on an extended leg, but then you immediately flex your knee as you start to make that contact.

   7. LFLex Fridman21:28

      Mm-hmm.

   8. RPRobert Playter21:28

      And getting that all to work well took such a long time. In fact, I, I probably didn't really see the nice natural walking that I expected out of our humanoids until maybe last year. And the team was developing on our newer generation of Atlas, you know, some new techniques, um, uh, for developing a walking control algorithm, and they got that natural looking motion as sort of a byproduct of a, of a just a different process they were applying to developing the control. So, that probably took 15 years, uh, 10 to 15 years to sort of get that from, from, you know... The Petman Prototype was probably in 2008, and what was it? 2022, (laughs) last year that I think I saw good walking on Atlas.

   9. LFLex Fridman22:16

      I- if you could just, like, linger on it, what are some challenges of getting good walking? So, is it, um, is this, (laughs) is this partially like a hardware, like, actuator problem? Is it the control? Is it the artistic element of just observing the whole system operating in different conditions together? I mean, is there some kind of interesting quirks or challenges you can speak to, like the heel strike or all this kind of-

   10. RPRobert Playter22:41

       Yeah, so one of the things that makes the, like, this straight leg, uh, a challenge is you're sort of up against a, a singularity, a m- a mathematical single- singularity, where, you know, when, when your leg is fully extended, it can't go further the other direction, right?

   11. LFLex Fridman22:56

       Mm-hmm.

   12. RPRobert Playter22:56

       There's only... You can only move in one direction, and that makes all of the calculations around how to produce torques at that joint, or positions, makes it more complicated. And so having all of the mathematics so it can deal with these singular configurations is one of many (laughs) challenges, uh, uh, that we face. And, and I'd say in, in the, you know, in those earlier days, again, we were working with these really simplified models, so we're trying to boil all the physics of the complex human body into a simpler subsystem that we can more easily describe in mathematics. And sometimes those simpler subsystems don't have all of that complexity of the s- straight leg built into them. And so, um, what's, what's happened more recently is we're able to apply techniques that let us take the full physics of the, um, uh, robot into account, and, and deal with some of those, uh, strange situations like the, like the straight leg.

   13. LFLex Fridman23:59

       So, is there a fundamental challenge here that it's... Uh, maybe you can correct me, but is it underactuated? Are you falling?

   14. RPRobert Playter24:06

       Underactuated is, is the right word, right? You can't, you can't, uh, push the robot in any direction you want to.

   15. LFLex Fridman24:12

       Yeah.

   16. RPRobert Playter24:12

       Right? And so that, that is one of the hard problems of, of, uh, legged locomotion.

   17. LFLex Fridman24:16

       And you have to do that for natural movement?

   18. RPRobert Playter24:19

       It's not necessarily required for natural movement. It's just required... You know, we, we don't have, you know, a gravity force that you can hook yourself onto to apply, uh, an, an external force in the direction you want at all times, right? The only-

   19. LFLex Fridman24:34

       Yeah.

   20. RPRobert Playter24:34

       ... the only external forces are being mediated through your feet, and how they get mediated depend on how you place your feet. And, uh, you know, you can't just, uh, you know... God's hand can't reach down and give and, and push in any direction you want, (laughs) you know, so...

   21. LFLex Fridman24:49

       Is there, uh, is there some extra challenge to the fact that Atlas is such a big robot?

   22. RPRobert Playter24:54

       There is. The humanoid form is, um, um, attractive in many ways, but it's also a challenge in many ways. Um, y- you have this big upper body that has a lot of mass and inertia, um, and throwing that inertia around increases the complexity of maintaining balance. And as soon as you pick up something heavy in your arms, you've made that problem even harder. And so, uh, in the early work, in the leg lab and in the early days at the company, you know, we were pursuing these quadruped robots, which had a, a kind of built-in simplification. You had this big rigid body and then really light legs. So, when you swing the legs, the leg motion didn't impact the body motion very much. All the mass and inertia was in the body. But when you have the humanoid, that doesn't work. You have big heavy legs. You swing the legs, it affects everything else. And so dealing with all of that interaction does make the humanoid a much more complicated platform.

   23. LFLex Fridman25:58

       And I also saw that, uh, at least recently, you've been doing more explicit modeling of the stuff you pick up.

   24. RPRobert Playter26:04

       Yeah. Yeah.

   25. LFLex Fridman26:05

       Which is very r- (laughs) um, really interesting. So, you have to, what? Model the shape, the weight distribution? I don't know. What... Like, you have to under- like, include that as part of the modeling, as part of the planning 'cause... Okay, so for people who don't know, uh, so Atlas, at least in, like, the recent video, like, throws a heavy bag, throws a bunch of-

   26. RPRobert Playter26:30

       Yeah.

   27. LFLex Fridman26:30

       (laughs) ... stuff. So, what, what's involved in, uh, picking up a thing, a heavy thing, uh, and when that thing is a bunch of different nonstandard things? I think it also picked up, like, a barbell and, uh, to be able to throw it in some cases. What's, what are some interesting challenges there?

   28. RPRobert Playter26:48

       So, we were definitely trying to show that the robot and the techniques we're applying to the ro- uh, to Atlas let us deal with heavy things in the world.

   29. LFLex Fridman26:58

       Yeah.

   30. RPRobert Playter26:58

       Because if the robot's going to be useful, it's actually got to move stuff around.
6. 36:53 – 51:13

   DARPA Robotics Challenge

   1. LFLex Fridman36:53

      bit to, uh, the DARPA Robotics Challenge in 2015, I think, which was, for people who aren't familiar with the DARPA challenges, it, uh, was f- first with autonomous vehicles, and there's a lot of interesting challenges around that. And the DARPA Robotics Challenge was when, uh, humanoid robots were tasked to do all kinds of, uh, uh, you know, manipulation, walking, uh-

   2. RPRobert Playter37:21

      Driving a vehicle.

   3. LFLex Fridman37:21

      ... driving a car, all these kinds of challenges, with, if I remember correctly, sort of some slight capability to communicate with humans. But, uh, the communication was very poor, so basically it has to be almost entirely autonomous.

   4. RPRobert Playter37:37

      It could have periods where the communication was entirely interrupted and the robot had to be able to proceed.

   5. LFLex Fridman37:42

      Yeah.

   6. RPRobert Playter37:42

      But you could provide some high-level guidance to the robot, basically low, low-bandwidth communications, uh-

   7. LFLex Fridman37:48

      Yeah.

   8. RPRobert Playter37:48

      ... to steer it.

   9. LFLex Fridman37:49

      I watched that challenge with kind of tears in my eyes, eating popcorn. W- with har-

   10. RPRobert Playter37:55

       Us too. (laughs)

   11. LFLex Fridman37:56

       (laughs) But I w- I wasn't personally losing, uh, you know, uh, hundreds of thousands, millions of dollars and many years of incredible hard work by some of the most brilliant roboticists in the world. So that, that was why the tragic, that's why-

   12. RPRobert Playter38:10

       (laughs)

   13. LFLex Fridman38:10

       ... the tears came. So anyway, what, what have you, um... Just looking back to that time, what have you learned from that experience? Uh, maybe if you could describe what it was, uh, sort of to set up for people who haven't seen it.

   14. RPRobert Playter38:23

       Well, so there was a contest where a bunch of different, um, robots were asked to do a series of tasks, uh, some of those that you mentioned, drive a vehicle, get out, open a door, go identify a valve, shut a valve, use a tool to maybe cut a hole in, um, a, a surface, and then crawl over some stairs and maybe some rough terrain. So, it was, the idea was have a, a general-purpose robot that could do lots of different things. Um, had to be mobility and manipulation, onboard perception. And there was a contest, uh, which DARPA likes, uh, at the time was running sort of follow on to the, the Grand Challenge, which was, let's, let's try to push vehicle autonomy along, right? They, they, they encouraged people to build autonomous cars. So, they're trying to basically push an industry forward.

   15. LFLex Fridman39:20

       Mm-hmm.

   16. RPRobert Playter39:21

       And, um, uh, we were asked... Our role in this was to build, um, a humanoid. At the time, it was our sort of first generation Atlas robot. And, uh, we built maybe 10 of them. I don't remember the exact number. Uh, and DARPA distributed those to various teams, um, that sort of won a, a contest, uh, showed that they, uh, could, you know, program these robots and then used them to compete against each other. And then, other robots were introduced as well. Some teams built their own robots. Carnegie, um, Mellon, for example, built their own robot. And, uh, and all these robots competed to see who could sort of get through this, this maze, um, uh, the fastest. And, uh, again, I think the purpose was to kind of push the whole industry forward. Uh, we provided the robot and some baseline software, but we didn't, we didn't actually compete as a participant-

   17. LFLex Fridman40:19

       Mm-hmm.

   18. RPRobert Playter40:20

       ... uh, where we were trying to, uh, you know, drive the robot through this maze. Uh, we were just trying to support the other teams. It was humbling because it was, it was really a hard task. And, and honestly, the robots, the tears were because mostly the robots didn't do it. (laughs) You know?

   19. LFLex Fridman40:36

       Yeah.

   20. RPRobert Playter40:36

       They fell down, you know, uh, repeatedly. Um, it was hard to get through this contest. Uh, you know, some did, and, and, you know, they were rewarded and won. But it was humbling because of just how hard... These tasks weren't all that hard. A person could have done it very easily. Um, but it was really hard, uh, to get the robots to do it, you know? And, uh-

   21. LFLex Fridman40:57

       Well, the-

   22. RPRobert Playter40:57

       ... hard-

   23. LFLex Fridman40:57

       ... the general nature of it, the, the variety of it.

   24. RPRobert Playter41:00

       The variety.

   25. LFLex Fridman41:01

       And also, that I don't know if the tasks were, (sighs) sort of... The task in themselves help us understand what is difficult and what is not. I don't know if that was obvious before the contest was designed. So, you kind of tried to figure that out. And I think, uh, Atlas is really a general robot platform, and it's perhaps not best suited for the specific tasks of that contest. Like, for, for just for example, probably the hardest task is not the driving of the car, but getting in and out of the car.

   26. RPRobert Playter41:35

       (laughs)

   27. LFLex Fridman41:35

       And Atlas probably... You know, if you were to design a robot that can get into the car easily and get out easily, you probably would not make Atlas, that particular car.

   28. RPRobert Playter41:45

       Yeah. The, the robot was a little bit big-

   29. LFLex Fridman41:47

       Yeah.

   30. RPRobert Playter41:47

       ... to get in and out of that car.
7. 51:13 – 1:05:02

   BigDog robot

   1. RPRobert Playter51:13

      we, we had, uh, had to take BigDog to Thailand years ago.

   2. LFLex Fridman51:19

      Mm-hmm.

   3. RPRobert Playter51:20

      And, uh, we did this great video of the robot walking in the sand, walking into the ocean-

   4. LFLex Fridman51:27

      Mm-hmm.

   5. RPRobert Playter51:27

      ... up to, I don't know, its belly or something like that, and then turning around and walking out-

   6. LFLex Fridman51:32

      Yes.

   7. RPRobert Playter51:32

      ... all while playing some cool beach music.

   8. LFLex Fridman51:34

      Yeah.

   9. RPRobert Playter51:35

      Great show, but then, you know, we didn't really clean the robot off, and the salt water was really hard on it. So, uh, we, you know, we put it in a box, shipped it back. By the time it, it came back, we had some problems (laughs) with corrosion.

   10. LFLex Fridman51:45

       So, it's a salt, it's a salt water. It's not like-

   11. RPRobert Playter51:48

       It's salt stuff. (laughs)

   12. LFLex Fridman51:49

       It's not like sand getting into the components or something like this.

   13. RPRobert Playter51:52

       Yeah. Yeah.

   14. LFLex Fridman51:52

       But I'm sure if, if this is a big priority, you could make it, like-

   15. RPRobert Playter51:55

       Right.

   16. LFLex Fridman51:55

       ... waterproof or something.

   17. RPRobert Playter51:56

       Right, right. That just wasn't our, our goal at the time.

   18. LFLex Fridman51:59

       Well, it's a personal goal of mine to, uh-

   19. RPRobert Playter52:01

       (laughs)

   20. LFLex Fridman52:02

       ... walk along, walk along the beach. But it's, it's a human problem, too. You get sand everywhere. It's, it's just a giant mess.

   21. RPRobert Playter52:07

       (laughs)

   22. LFLex Fridman52:08

       Uh, so soft surfaces are okay. So, I mean, can we just, uh, linger on the, the robotics challenge? There was, um, there's a pile of, uh, like rubble they had to walk over. Is that, um, how difficult is that task?

   23. RPRobert Playter52:24

       In the early days of developing BigDog, the loose rock was the epitome of the hard walking surface because you step down, and then the rock, and you had these little point feet on the robot, and the rock can roll.

   24. LFLex Fridman52:36

       Mm-hmm.

   25. RPRobert Playter52:37

       And, and you have to deal with that last minute, you know, change in your foot placement.

   26. LFLex Fridman52:43

       Yeah, so you, you step on a thing, and that thing responds to you stepping on it.

   27. RPRobert Playter52:47

       Yeah. And, and it moves where your point of support is.

   28. LFLex Fridman52:50

       Okay.

   29. RPRobert Playter52:50

       And so, it's really that, that became kind of the essence of the test. And so, that was the beginning of us starting to build rock piles in our parking lots, and-

   30. LFLex Fridman53:02

       (laughs)
8. 1:05:02 – 1:26:27

   Spot robot

   1. RPRobert Playter1:05:02

   2. LFLex Fridman1:05:02

      So, when, uh, was Spot born?

   3. RPRobert Playter1:05:06

      Around 2000 and, uh, 12 or so. So, again, almost 10 years into sort of a run with DARPA where we built a bunch of different quadrupeds. We had a sort of a different thread where we started building humanoids. Um, we, we, we saw that probably an end was coming where the government was gonna kind of back off from a lot of robotics investment. And, uh, w- in order to maintain progress, we just deduced that, "Well, we probably need to sell ourselves to somebody who wants to continue to invest in this, this area," and that was Google. And so, um, uh, at Google, we would meet regularly with Larry Page. And Larry just started asking us, you know, "Well, what's your product gonna be?"

   4. LFLex Fridman1:05:55

      Mm-hmm.

   5. RPRobert Playter1:05:56

      And, you know, the logical thing, the thing that we had the most history with-

   6. LFLex Fridman1:06:01

      Mm-hmm.

   7. RPRobert Playter1:06:01

      ... that we wanted to continue developing was a quadruped, but we knew it needed to be smaller. We knew it couldn't have a gas engine. We th- we thought it probably couldn't be hydraulically actuated. So, that began the process of exploring if we could migrate to a smaller, electrically actuated, um, robot, and that was really the genesis of Spot.

   8. LFLex Fridman1:06:24

      So, not a gas engine, and the actuators are electric.

   9. RPRobert Playter1:06:28

      Yes.

   10. LFLex Fridman1:06:28

       So, can you maybe comment on what it's like, um, at Google with working with Larry Page, having those meetings and thinking of what are, will a robot look like that could be built at scale? What ... like, starting to think about a product.

   11. RPRobert Playter1:06:45

       Larry always liked the, the toothbrush test. He wanted products that you used every day.Um, what they really wanted was, you know, a consumer-level product, something that would work in your house. We didn't think that was the right next thing to do-

   12. LFLex Fridman1:07:05

       Mm-hmm.

   13. RPRobert Playter1:07:06

       ... because to be a consumer-level product, cost is gonna be very important. It probably needed to cost a few thousand dollars, and we were, we were building these machines that cost hundreds of thousands of dollars, maybe a million dollars to build. Of course, we were only building, like, two, but-

   14. LFLex Fridman1:07:22

       Mm-hmm.

   15. RPRobert Playter1:07:23

       ... but we didn't see how to get all the way to this consumer-level product-

   16. LFLex Fridman1:07:27

       In a short amount of time.

   17. RPRobert Playter1:07:27

       ... in a short amount of time. And he suggested that we, we make the robots really inexpensive. And part of our philosophy has always been, build the best hardware you can. Make, make the machine operate well so that you're trying to solve, you know, discover the, the hard problem that you don't know about. Don't, don't make it harder by, by building a crappy machine, basically.

   18. LFLex Fridman1:07:54

       Mm-hmm.

   19. RPRobert Playter1:07:55

       Build the best machine you can. There's plenty of hard problems to solve that are gonna have to do with, you know, under-actuated systems and balance.

   20. LFLex Fridman1:08:02

       Mm-hmm.

   21. RPRobert Playter1:08:03

       And so we wanted to build these high-quality machines still, and we thought that was important for us to continue learning about really what was im- the important parts of, that make robots work. Um, and so there was a little bit of a phil- philosophical difference there that we... And, and so ultimately, that's why we're building robots for the industrial sector now, because the industry can afford a more expensive machine because, you know, their productivity depends on keeping their factory going. And so if Spot costs, you know, um, $100,000 or more, that's not such a big expense to them, whereas at the consumer level, no one's gonna buy a robot like that. And I think we might eventually get to a consumer-level product that will be that cheap. But I think the path to getting there needs to go through these really nice machines so that we can then learn how to simplify.

   22. LFLex Fridman1:08:57

       So, what can you say to the almost engineering challenge of bringing down cost of a robot? So that presumably when you try to build a robot at scale, that also comes into play when you're trying to make money on a robot, even in, in the industrial setting. But how interesting, how challenging, uh, of, of a thing is that, sp- in particular probably new to an R&D company?

   23. RPRobert Playter1:09:25

       (laughs) Yeah, I'm glad you brought that last part up. The transition from an R&D company to a commercial company, that's the thing you worry about. You know, 'cause you've got these engineers who love hard problems, who want to figure out how to make robots work, and you don't know if you have engineers that want to work on the quality and reliability and cost that is ultimately required. Um, and indeed, you know, we have brought on a lot of new people who are inspired by those problems. But, but the big takeaway lesson for me is, we have good people. We have engineers who want to solve problems, and, and the quality and cost and manufacturability is just another kind of problem. And because they're so invested in what we're doing, they're interested in and will go work on, on those problems as well. And so I think we're managing that transition very well. In fact, I'm really pleased that... I mean, uh, it's a huge undertaking by the way, right? So, you know, even having... To get reliability to where it needs to be, we have to have fleets of robots that we're just operating 24/7 in our offices to go find those rare failures and, and eliminate them. It's a, just a totally different kind of activity than the research activity where you get it to work, you know, the one robot you have, uh, to work in a repeatable way, (laughs) you know, at the, at the high-stakes demo. It's just very different. Um, but I think we're making remarkable progress, I guess.

   24. LFLex Fridman1:10:54

       So one of the cool things, I got a chance to, uh, visit Boston Dynamics, and I mean, one, one of the things that's really cool is to see a large number of robots moving about, because I think one of the things you notice in the research, uh, environment is that at MIT, for example, I don't think anyone ever has a working robot for a prolonged period of time.

   25. RPRobert Playter1:11:18

       (laughs) Exactly.

   26. LFLex Fridman1:11:19

       So, like, most robots are just sitting there in a sad state of despair, waiting to be born, brought to life for a brief moment of time. But just to have... I just, I just remember there's like a, there's a Spot robot just, uh, had, like, a cowboy hat on. It was just walking randomly for whatever reason. I don't even know. But there's a kind of a sense of sentience to it because it doesn't seem like anybody was supervising it. (laughs)

   27. RPRobert Playter1:11:45

       Well-

   28. LFLex Fridman1:11:45

       It was just doing its thing.

   29. RPRobert Playter1:11:46

       ... I'm gonna stop way short of the sentience.

   30. LFLex Fridman1:11:48

       Sure.

Episode duration: 2:27:57