WEBVTT - TechStuff Takes a Walk with Robots 0:00:04.480 --> 0:00:12.360 Welcome to Tech Stuff, a production from iHeartRadio. Hey therein 0:00:12.520 --> 0:00:16.400 Welcome to Tech Stuff, I'm your host, Jonathan Strickland. I'm 0:00:16.440 --> 0:00:19.880 an executive producer with iHeart Podcasts and how the tech 0:00:19.960 --> 0:00:24.600 are you? So? Last week, Tesla held an event called 0:00:24.880 --> 0:00:28.240 we Robot, in which attendees got to see a new 0:00:28.320 --> 0:00:32.480 vehicle that was dubbed the robo Van, although Elon Musk 0:00:32.560 --> 0:00:36.760 pronounced it as reboven. There was a cyber cab that 0:00:37.440 --> 0:00:39.920 must claims is going to cost less than thirty thousand 0:00:39.960 --> 0:00:43.520 dollars when it goes into production sometime before twenty twenty seven, 0:00:43.640 --> 0:00:47.159 which would potentially allow the average person to run a 0:00:47.280 --> 0:00:50.519 small uber or lift business out of their own garage 0:00:50.760 --> 0:00:53.800 with the cybercab giving people rides. Though that raises a 0:00:53.800 --> 0:00:57.640 lot of questions I have, like liability issues. Let's say 0:00:57.640 --> 0:01:00.720 that your cybercab got into an act extent. Are you 0:01:00.840 --> 0:01:03.800 held liable for that? Or is Tesla or I don't know. 0:01:04.240 --> 0:01:07.440 That's a discussion for another time. But they also gave 0:01:07.440 --> 0:01:12.160 a closer look at the humanoid Optimus robots, and they 0:01:12.160 --> 0:01:15.399 had robots that were dancing and serving drinks and some 0:01:15.520 --> 0:01:19.520 that even held conversations with attendees. Now, those robots had 0:01:19.680 --> 0:01:22.520 some help. Tesla also did not hide this fact. This 0:01:22.600 --> 0:01:25.199 is not like a gotcha because the company was very 0:01:25.319 --> 0:01:30.760 forthright about this. Remote operators were augmenting the robot's abilities 0:01:30.840 --> 0:01:33.600 while those robots were on the floor. So, for example, 0:01:33.640 --> 0:01:37.160 those conversations were actually human beings who were using the 0:01:37.240 --> 0:01:41.360 robots kind of like an advanced bipedal intercom system. But 0:01:41.560 --> 0:01:45.080 it made me think about the long history of humans 0:01:45.160 --> 0:01:50.320 trying to make humanoid robots. Now, in some ways this 0:01:50.400 --> 0:01:56.480 pursuit is a bit strange because a legged, bipedal humanoid 0:01:56.600 --> 0:02:00.360 robot brings with it a ton of challenges that you 0:02:00.440 --> 0:02:04.200 could sidestep if you just made some compromises to your 0:02:04.240 --> 0:02:07.480 design approach, like why does the robot need to be 0:02:07.560 --> 0:02:11.720 bipedal and humanoid? If you decided the robot should move 0:02:11.760 --> 0:02:15.600 around on wheels or tank treads, or maybe move around 0:02:15.600 --> 0:02:18.920 on all fours, or maybe you make like a centaur 0:02:19.240 --> 0:02:21.680 like robot where it has like a base with four 0:02:21.800 --> 0:02:25.240 legs and then a torso with two arms and it 0:02:25.280 --> 0:02:28.520 stands upright. You know, we make the rules like it 0:02:28.520 --> 0:02:32.360 doesn't have to take any specific form factor, and you 0:02:32.360 --> 0:02:34.440 could do that and get around a lot of the 0:02:34.520 --> 0:02:38.000 challenges you would face if you were to instead focus 0:02:38.000 --> 0:02:41.919 on this humanoid bipedal approach. Creating a robot that can 0:02:42.000 --> 0:02:46.359 move the way humans do is hard. It has taken 0:02:46.800 --> 0:02:50.880 decades of research and development to accomplish that to a 0:02:50.960 --> 0:02:55.440 reliable degree, and even then it's typically under very controlled circumstances. 0:02:55.720 --> 0:03:00.040 When you start getting into stuff like uneven terrain, it 0:03:00.120 --> 0:03:04.520 gets a lot trickier. Okay, In other ways, the desire 0:03:04.560 --> 0:03:08.600 to build a human like robot is totally understandable. You know, 0:03:08.680 --> 0:03:12.920 my first reaction to anyone talking about developing a humanoid 0:03:13.040 --> 0:03:16.679 robot is why why are you doing that? What's your reasoning? 0:03:16.960 --> 0:03:19.920 Because if you can accomplish the same goal using a 0:03:19.919 --> 0:03:24.520 different method of locomotion, that might be the better choice. However, 0:03:24.840 --> 0:03:27.040 if you want this robot to be able to do 0:03:27.280 --> 0:03:31.760 tasks in our human world, like tasks that human beings 0:03:31.760 --> 0:03:34.680 would typically carry out on their own, well, making the 0:03:34.840 --> 0:03:38.640 robot human shaped makes more sense. You don't have to 0:03:38.960 --> 0:03:43.520 adapt your environment to the abilities of the robot, right 0:03:43.920 --> 0:03:46.960 because a set of stairs or a ladder would defeat 0:03:47.080 --> 0:03:51.600 most wheeled robots. They would come to it and say, well, 0:03:51.960 --> 0:03:56.360 I can't navigate up this obstacle, and if my goal 0:03:56.480 --> 0:03:59.000 is on the other end of that obstacle, that's a problem. 0:03:59.200 --> 0:04:03.080 So to really maneuver within the human world, it helps 0:04:03.120 --> 0:04:08.000 to have your typical human shape and typical human capabilities. Now, 0:04:08.000 --> 0:04:10.680 the flip side of this is that we humans, we 0:04:10.720 --> 0:04:13.720 have an obligation to make spaces accessible for those who 0:04:13.800 --> 0:04:17.359 have an atypical shape or atypical capabilities. We need to 0:04:17.360 --> 0:04:21.240 make sure that people who don't have the use of say, 0:04:21.400 --> 0:04:25.680 their legs, can still access really important stuff. That's a 0:04:25.839 --> 0:04:30.840 responsibility we have, but that's a topic for another episode. Plus, 0:04:30.920 --> 0:04:34.440 I think there is something inherent within us, or at 0:04:34.520 --> 0:04:39.000 least inherent within some of us, some human beings, and 0:04:39.080 --> 0:04:42.400 it drives us to want to create companions that look 0:04:42.600 --> 0:04:46.480 and to an extent behave the way we do. So 0:04:46.839 --> 0:04:51.880 much of science fiction is based around variations of this idea. 0:04:52.120 --> 0:04:57.760 Arguably Mary Shelley's Frankenstein is kind of along this track 0:04:57.800 --> 0:05:00.960 of thinking. You know, you have you your crazy scientists 0:05:01.000 --> 0:05:04.240 who desires to play god, and then you have General 0:05:04.320 --> 0:05:09.160 Capex's influential work, Rossum's Universal Robots. That's the work where 0:05:09.160 --> 0:05:12.039 we get the term robot in the first place, or 0:05:12.240 --> 0:05:17.320 the replicants in Blade Runner, which actually pretty closely resemble 0:05:17.400 --> 0:05:20.839 the robots in capex work, to the works of Isaac 0:05:20.880 --> 0:05:25.440 Asimov and beyond. So in many of these pieces there's 0:05:25.640 --> 0:05:30.160 a warning that is given that the pursuit to build 0:05:30.400 --> 0:05:35.760 and exploit robots often comes tinged with arrogance and hubris, 0:05:36.080 --> 0:05:39.040 and it rarely works out well for anybody by the 0:05:39.120 --> 0:05:43.000 end of the story. Now, not all of those robots 0:05:43.279 --> 0:05:47.880 were mechanical or electro mechanical or digital creatures. In fact, 0:05:48.040 --> 0:05:52.039 like Frankenstein's Monster, the robots in Capex's work and the 0:05:52.120 --> 0:05:56.080 replicants in Blade Runner are all synthetic life forms. They're 0:05:56.120 --> 0:06:00.680 not masses of wires and circuit boards. Asimov's work introduced 0:06:00.800 --> 0:06:06.040 more mechanical and electro mechanical creatures with artificial brains. But ultimately, 0:06:06.400 --> 0:06:11.240 all the stories involve creatures and creations that gain an 0:06:11.279 --> 0:06:14.960 awareness of themselves and their place in the world, and 0:06:15.000 --> 0:06:18.480 how they reject the hand that has been dealt to them, 0:06:18.600 --> 0:06:23.200 often to dramatic and catastrophic degrees. Now, what the future 0:06:23.279 --> 0:06:26.760 holds as far as humanoid robots go has yet to 0:06:26.839 --> 0:06:29.400 be written, though we can certainly look back and talk 0:06:29.400 --> 0:06:32.320 about some of the history in the field of humanoid 0:06:32.400 --> 0:06:36.000 robots that have happened so far. Before robots, we have 0:06:36.080 --> 0:06:41.560 examples of automata that mimiced human movement and capabilities. Some 0:06:41.640 --> 0:06:45.360 of these were actual clockwork creations, such as the Karakuri. 0:06:45.480 --> 0:06:48.160 These are puppets from Japan, dating as far back as 0:06:48.200 --> 0:06:53.120 the seventeenth century, so the sixteen hundreds. These used mechanisms 0:06:53.160 --> 0:06:58.599 to power certain movements, usually repeatable movements like serving tea 0:06:59.240 --> 0:07:04.640 or playing musical instrument. Some of the early automata weren't 0:07:04.680 --> 0:07:08.559 automata at all. They were hoaxes. The famed mechanical Turk 0:07:08.760 --> 0:07:13.720 creation of Wolfgang von Kemplan is such an example. Kempland 0:07:13.760 --> 0:07:17.640 actually stowed a human operator inside a cabinet that was 0:07:17.680 --> 0:07:21.720 attached to this supposed automaton that had been designed to 0:07:21.760 --> 0:07:25.320 play chess. In reality, it was the human operator hidden 0:07:25.320 --> 0:07:28.040 inside the cabinet that was controlling everything. It was really 0:07:28.080 --> 0:07:32.119 just a puppet, not an automaton. But these creations, whether 0:07:32.440 --> 0:07:37.120 actual automata or not, were limited in function, and typically 0:07:37.120 --> 0:07:40.520 they weren't bipedal either, not truly like they weren't moving 0:07:40.560 --> 0:07:43.080 around on two legs. They might be stationary in the 0:07:43.080 --> 0:07:47.320 case of the mechanical turk, or they might have wheels 0:07:47.840 --> 0:07:51.720 and they have like robes that cover up the wheels, 0:07:51.760 --> 0:07:54.040 so it looks like they're kind of gliding across, but 0:07:54.080 --> 0:07:57.360 they're not actually walking. And I also have to include 0:07:57.960 --> 0:08:01.480 one story I came across because it's just too absurd 0:08:01.920 --> 0:08:06.240 to leave out. So in eighteen forty eight. In May 0:08:06.520 --> 0:08:09.960 of eighteen forty eight, a couple of different journals, one 0:08:10.000 --> 0:08:14.080 of them being Scientific American, published an account of a 0:08:14.120 --> 0:08:18.800 supposed encounter with a remarkable automaton that was capable of 0:08:19.280 --> 0:08:24.360 standing up, sitting down, and even of speaking. The automaton 0:08:24.400 --> 0:08:29.440 itself was apparently almost indistinguishable from a human being. The 0:08:29.480 --> 0:08:32.760 account was said to have originally published in quote an 0:08:32.840 --> 0:08:37.120 Augsburg Gazette end quote. So Augsburg is a city in 0:08:37.480 --> 0:08:41.119 Bavaria in Germany, and so the original article was supposedly 0:08:41.360 --> 0:08:44.240 written in German and then translated into English to be 0:08:44.280 --> 0:08:47.800 published in various periodicals in the United States and elsewhere. 0:08:48.160 --> 0:08:53.960 The automaton's name was mister Eisenbrass, which is great, but 0:08:54.120 --> 0:08:58.560 the name of the inventor was doctor Lube, which, y'all, 0:08:58.840 --> 0:09:02.120 that's like a gift from the gods of comedy right there. 0:09:02.360 --> 0:09:06.880 Mister Eisenbrass and Doctor Lube. I maintain that someone should 0:09:06.920 --> 0:09:10.439 make a stage production that has the title mister Eisenbrass 0:09:10.440 --> 0:09:13.240 and Doctor Lube, and it might well be me unless 0:09:13.280 --> 0:09:15.840 someone beats me to it. And someone probably will beat 0:09:15.880 --> 0:09:17.760 me to it, because I'm infamous for coming up with 0:09:17.840 --> 0:09:21.240 ideas for shows or novels or whatever and then just 0:09:21.280 --> 0:09:25.440 sitting on them. But my goodness, mister Eisenbrass and Doctor Lube. 0:09:25.880 --> 0:09:30.160 That's that's a title, y'all. Anyway, according to this article, 0:09:30.360 --> 0:09:33.360 the author and some other visitors went to the lab 0:09:33.800 --> 0:09:37.840 of doctor Lube, which I imagine was down a slippery slope. Anyway, 0:09:38.000 --> 0:09:41.600 The doctor was quote seated at a sort of cabinet 0:09:41.679 --> 0:09:45.120 having a keyboard somewhat similar to that of a piano 0:09:45.240 --> 0:09:48.600 forte arranged on one side of it, and nearly in 0:09:48.640 --> 0:09:52.559 the center of a room sat a fashionably dressed gentleman 0:09:52.720 --> 0:09:56.920 who rose and bowed as we entered endo quote. And then, 0:09:57.040 --> 0:10:00.400 according to the article, the visitors engaged in some small 0:10:00.480 --> 0:10:04.600 talk with this fashionably dressed gentleman, and the gentleman actually 0:10:04.600 --> 0:10:07.880 took a seat after the visitors had sat down, and 0:10:07.960 --> 0:10:11.800 eventually the doctor stops playing at his keyboard, and mister 0:10:11.920 --> 0:10:15.920 Eisenbrass goes quiet, and Lube explains that the whole thing 0:10:16.000 --> 0:10:19.560 is a mechanical contraption. Only then do the visitors notice 0:10:19.679 --> 0:10:22.960 the cables going from the keyboard console to the chair 0:10:23.080 --> 0:10:27.800 of mister Eisenbrass. Now, according to the piece, Lube procured 0:10:28.160 --> 0:10:32.320 bones from a human being, presumably a dead one, which 0:10:32.360 --> 0:10:35.200 is a big ol' ick already, but then use rubber 0:10:35.280 --> 0:10:38.520 tubes to kind of serve as musculature, and that he 0:10:38.600 --> 0:10:42.959 also created quote a perfect system of nerves made of 0:10:43.400 --> 0:10:47.640 fine platinum wire and covered with silk end Quote to 0:10:47.720 --> 0:10:50.240 what end, you might say, what what are the nerves for? 0:10:51.160 --> 0:10:54.960 I guess the idea is that electric motors would pull 0:10:55.040 --> 0:10:58.400 upon the rubber tubes. It does explain that there were 0:10:58.480 --> 0:11:02.280 electro magnets that were in use in this system, and 0:11:02.320 --> 0:11:05.120 that the tubes just served as muscles that when you 0:11:05.559 --> 0:11:09.000 pulled on them, would cause the contraction you would associate 0:11:09.040 --> 0:11:12.079 with a human body. I actually at first assumed, since 0:11:12.080 --> 0:11:14.160 they were talking about rubber tubes, that this was going 0:11:14.200 --> 0:11:17.080 to be a pneumatic system where you would use air 0:11:17.400 --> 0:11:20.360 to achieve similar results. Right, you pump air into something 0:11:20.400 --> 0:11:24.000 to extend a limb, and you would allow air to 0:11:24.240 --> 0:11:27.600 escape to contract the limb. But that apparently is not 0:11:27.640 --> 0:11:31.280 how this was supposed to work. Supposedly, the keyboard allowed 0:11:31.280 --> 0:11:33.840 the doctor to produce incredible results just by pressing a 0:11:33.840 --> 0:11:36.080 few keys, like I guess there was a key that 0:11:36.160 --> 0:11:39.600 was just labeled small talk or something, and that the 0:11:39.679 --> 0:11:46.559 figure was apparently capable of quote walking, talking, singing, playing 0:11:46.600 --> 0:11:49.800 the piano, and doing many other things with as much 0:11:49.920 --> 0:11:54.160 ease and precision as an accomplished man. End quote. The 0:11:54.240 --> 0:11:58.800 author then proactively chides the reader for undoubtedly asking so 0:11:59.280 --> 0:12:01.920 what good is on this? And then the author goes 0:12:01.960 --> 0:12:04.920 on to talk about how mechanical servants will replace all 0:12:05.000 --> 0:12:09.400 those undependable lauts and scally wags who currently act as servants, 0:12:09.679 --> 0:12:12.520 and thus give the women of the household the freedom 0:12:12.600 --> 0:12:15.640 to carry out their feminine duties as caretaker of the 0:12:15.679 --> 0:12:19.199 home just by tickling some ivories. Yeah, this article is 0:12:19.280 --> 0:12:24.440 well and truly both sexist and classist. Anyway, to say 0:12:24.440 --> 0:12:28.120 that I am skeptical about this account is putting it lightly. 0:12:28.440 --> 0:12:33.080 I feel fairly certain that no such demonstration ever actually 0:12:33.120 --> 0:12:37.160 took place, or if there were some kind of demonstration, 0:12:37.280 --> 0:12:40.840 it did not unfold as described in this article. I 0:12:40.920 --> 0:12:44.320 did try to find the original article written in German. 0:12:44.760 --> 0:12:48.720 I assumed that the German gazette that was referenced in 0:12:48.800 --> 0:12:52.840 the English piece must have been the Algemina Zeitung that 0:12:52.960 --> 0:12:56.600 was published in Augsburg, Germany for most of the nineteenth century, 0:12:56.679 --> 0:12:59.760 and was like the main paper not just of Augsburg, 0:12:59.800 --> 0:13:03.199 but like of that region of Germany. However, I found 0:13:03.240 --> 0:13:09.160 no record of Eisenbrass or doctor Lube anyway. As diverting 0:13:09.240 --> 0:13:12.640 as mister Eisenbrass and doctor Lube are, I feel confident 0:13:12.640 --> 0:13:16.520 in saying that the capability of building a robot that 0:13:16.559 --> 0:13:20.920 could maintain its balance standing still, let alone walking around 0:13:21.040 --> 0:13:25.160 all without other means of support, was likely well outside 0:13:25.200 --> 0:13:28.640 the reach of even the most clever of innovators in 0:13:28.679 --> 0:13:31.720 the mid eighteen hundreds. That seems like that's just a 0:13:31.800 --> 0:13:34.959 no brainer. When it comes to creating a two legged robot, 0:13:35.280 --> 0:13:38.640 one where most of the mass is actually above the 0:13:38.720 --> 0:13:42.760 legs of the robot, not contained within the legs, things 0:13:42.760 --> 0:13:45.320 get really tricky because a lot of physics have to 0:13:45.320 --> 0:13:49.600 be considered before engineers could get serious about bipedal robots. 0:13:49.840 --> 0:13:53.040 If we relied solely on trial and error and just 0:13:53.080 --> 0:13:55.840 figured we're going to get this right, we'd likely not 0:13:55.920 --> 0:13:59.120 be anywhere as far along as we are right now. 0:13:59.440 --> 0:14:03.040 So when we come back, we're going to consider how 0:14:03.240 --> 0:14:07.440 challenging it is to create something that walks around on 0:14:07.559 --> 0:14:10.240 two legs. But before we get to that, and I 0:14:10.280 --> 0:14:14.080 get a little unbalanced, let's take a quick break to 0:14:14.120 --> 0:14:27.080 thank our sponsors. All right, So what's the big deal 0:14:27.120 --> 0:14:29.640 with walking around on two legs? Lots of people do 0:14:29.720 --> 0:14:32.600 it all the time. You know, toddlers can get the 0:14:32.640 --> 0:14:36.680 hang of it without too much trouble, and we celebrate 0:14:36.720 --> 0:14:38.800 it when it happens like that's a big deal, But 0:14:38.840 --> 0:14:41.920 then shortly after that it's It really becomes just a 0:14:41.960 --> 0:14:46.600 source of stress as the toddlers toddle along toward one 0:14:46.680 --> 0:14:51.120 danger or another. But you're entirely dependent upon just two 0:14:51.240 --> 0:14:54.840 points of contact with your surrounding environment. If you're talking 0:14:54.840 --> 0:14:59.680 about a true bipedal form that is capable of moving 0:14:59.720 --> 0:15:03.680 around round the area, and those two points of contact 0:15:03.680 --> 0:15:07.320 with the environment are essentially the bottoms of the foot seats. That's, 0:15:07.520 --> 0:15:10.120 of course, if everything is actually going as you wanted 0:15:10.160 --> 0:15:12.440 it to. If things have gone poorly, you might actually 0:15:12.440 --> 0:15:14.720 have lots of different points of contact with the ground. 0:15:14.800 --> 0:15:17.800 But that's because you went horizontal after something went wrong. 0:15:18.200 --> 0:15:21.840 So you've got your robot. It's got two legs, the 0:15:21.960 --> 0:15:23.800 two points of contact with the ground or the bottom 0:15:23.800 --> 0:15:26.960 of the feet likely the legs and the feet, and 0:15:27.200 --> 0:15:30.200 your robot in general has a number of degrees of freedom. 0:15:30.640 --> 0:15:34.120 So degrees of freedom are joints that allow movement along 0:15:34.240 --> 0:15:37.400 at least one axis. The point of contact with the 0:15:37.440 --> 0:15:41.040 ground could actually be considered a passive degree of freedom 0:15:41.360 --> 0:15:45.000 in itself. And you're also relying on friction to allow 0:15:45.040 --> 0:15:49.560 your robot to stand up, to maintain balance, and to 0:15:49.680 --> 0:15:53.080 get anywhere. If the robot's feet were frictionless, then it 0:15:53.120 --> 0:15:54.800 wouldn't be able to stay up right at all, let 0:15:54.840 --> 0:15:58.160 alone walk. And you've got all this weight above the 0:15:58.280 --> 0:16:01.880 legs that you have to worry about. So have you 0:16:01.960 --> 0:16:05.960 ever balanced something like, say, a baseball bat, on the 0:16:06.000 --> 0:16:08.640 palm of your hand. If you do that with a 0:16:08.640 --> 0:16:11.680 baseball bat and you're using the narrow part the handle 0:16:11.720 --> 0:16:13.680 in of the words of the bat and you're balancing 0:16:13.680 --> 0:16:15.840 that on your palm and the thick part of the 0:16:15.880 --> 0:16:18.760 bat is up in the air, you know that little 0:16:18.800 --> 0:16:23.720 motions can create big results. Right A small movement at 0:16:23.720 --> 0:16:26.000 the base can cause the top to really sway, and 0:16:26.040 --> 0:16:28.600 that requires you to make larger corrections down at the 0:16:28.640 --> 0:16:31.040 base in order to keep everything in balance. Well, that's 0:16:31.160 --> 0:16:32.960 kind of what it's like to try and figure out 0:16:32.960 --> 0:16:37.200 how to make a bipedal robot walk while maintaining its balance. 0:16:37.240 --> 0:16:40.400 You've got a inertia to deal with, and that really 0:16:40.440 --> 0:16:44.160 affects balance. How do you make sure the mass above 0:16:44.240 --> 0:16:47.840 the legs doesn't throw everything off kilter whenever it starts 0:16:47.840 --> 0:16:50.760 moving or when it stops moving. How do you correct 0:16:50.760 --> 0:16:53.960 for that so that your robot doesn't just tumble over? 0:16:54.000 --> 0:16:57.760 How do you keep your bot upright? One early discussion 0:16:57.840 --> 0:17:01.359 that became a core component in the pursuit of bipedal 0:17:01.440 --> 0:17:05.600 robots revolved around a concept that came to be known 0:17:05.920 --> 0:17:10.920 as the zero moment point or ZMP. So a pair 0:17:10.960 --> 0:17:15.800 of smarty pants is from Russia named Beyomir Vukabratovich and 0:17:16.119 --> 0:17:21.679 Davor Jurichic first described this back in the nineteen sixties. Now, 0:17:21.760 --> 0:17:25.080 the actual term zero moment point would be coined a 0:17:25.119 --> 0:17:27.840 little bit later, but it was used to describe what 0:17:28.040 --> 0:17:32.080 they were talking about, and the whole concept revolves around 0:17:32.160 --> 0:17:35.600 a moment in which the net reaction forces between a 0:17:35.680 --> 0:17:41.719 bipedal mechanism's feet and the ground are essentially zero and 0:17:41.760 --> 0:17:45.639 there's no movement along the horizontal plane. So that means, 0:17:45.680 --> 0:17:50.080 like forward momentum and gravity they've kind of canceled each 0:17:50.080 --> 0:17:53.680 other out. You've hit this zero moment where you don't 0:17:53.720 --> 0:17:56.920 have to worry about the robot tipping forward and falling over. 0:17:57.320 --> 0:17:59.960 It is you could think of as a moment of stability, 0:18:00.480 --> 0:18:04.240 and the robot, assuming no external forces are acting upon it, 0:18:04.320 --> 0:18:09.879 will remain upright, assuming that ZMP is maintained. Now, this 0:18:09.960 --> 0:18:14.640 discussion really drives home how stability can be a huge challenge. 0:18:14.720 --> 0:18:17.919 As robots move, they must deal with inertia and you 0:18:18.040 --> 0:18:21.440 have to know the math to achieve dynamic stability if 0:18:21.440 --> 0:18:26.280 your robot is to remain upright, whether it's walking, running, jumping, 0:18:26.600 --> 0:18:29.280 or whatever. And in fact, it gets increasingly more difficult 0:18:29.520 --> 0:18:32.919 as you go down those tasks. Walking is hard, running 0:18:33.000 --> 0:18:37.560 is really hard, and jumping is really really hard. Like 0:18:38.119 --> 0:18:40.920 the jump part might be easy, the landing and staying 0:18:41.000 --> 0:18:44.800 upright that's the hard part. Otherwise your robot's gonna topple over. 0:18:45.080 --> 0:18:47.199 And while watching a robot take a tumble might be 0:18:47.240 --> 0:18:49.879 a great YouTube video. In practice, in the real world, 0:18:50.040 --> 0:18:52.560 you obviously don't want your robots to be falling over. 0:18:52.680 --> 0:18:55.199 You want your robots to be stable and capable of 0:18:55.240 --> 0:19:00.399 moving around environments without causing damage or potentially injury to people, 0:19:00.800 --> 0:19:04.879 to be able to maneuver. It's tough and robots are expensive. 0:19:05.080 --> 0:19:07.960 You don't want them falling over. Then you're thinking, well, 0:19:08.080 --> 0:19:10.520 that's twenty thousand dollars to get this thing back on 0:19:10.560 --> 0:19:13.680 its feet. Again, that's not a great way to reach 0:19:13.760 --> 0:19:17.760 progress either. So to plan the motion for a robot, 0:19:18.119 --> 0:19:20.399 you need to be able to calculate the zero moment 0:19:20.440 --> 0:19:23.920 point or ZMP. You need to figure out which joints 0:19:23.920 --> 0:19:26.280 the robot is going to have to engage in order 0:19:26.359 --> 0:19:30.560 to achieve stability under its various operating conditions, and those 0:19:30.560 --> 0:19:34.960 conditions could include things outside of your strict control. It's 0:19:35.000 --> 0:19:38.280 one thing to calculate how the robot can achieve stability 0:19:38.440 --> 0:19:41.399 when it's walking across a level floor that has a 0:19:41.440 --> 0:19:45.240 firm surface, But what about a floor that surface isn't 0:19:45.400 --> 0:19:47.800 as firm. Maybe it's a little squishy, you know, maybe 0:19:47.840 --> 0:19:51.520 it's a nineteen seventies shag carpet or something, or what 0:19:51.600 --> 0:19:54.720 if the floor isn't level, what if the terrain is 0:19:54.800 --> 0:19:57.560 actually uneven, you know, kind of like a typical sidewalk 0:19:57.560 --> 0:20:00.960 in the city of Atlanta. How does a robot compensate 0:20:01.080 --> 0:20:05.200 for all this, remain stable and keep itself from pitching over? 0:20:05.720 --> 0:20:09.000 This is a non trivial challenge, and it takes a 0:20:09.040 --> 0:20:11.320 lot of work to get to a point where robots 0:20:11.440 --> 0:20:16.320 are sophisticated enough to achieve stability. Engineers have had to 0:20:16.359 --> 0:20:19.800 take a lot into consideration. Would more degrees of freedom 0:20:19.880 --> 0:20:23.080 help or does that actually overcomplicate matters? I mean, there's 0:20:23.080 --> 0:20:26.480 no reason why we should be constrained to the same 0:20:26.520 --> 0:20:30.520 degrees of freedom that a person has. Right Like, we 0:20:30.560 --> 0:20:33.919 could think, oh, let's mimic the way humans work and 0:20:34.160 --> 0:20:36.560 make sure that the ankles and the knees and the 0:20:36.640 --> 0:20:39.439 hips all have the same points of articulation. Or we 0:20:39.480 --> 0:20:42.000 could say, well, there's no reason why we couldn't have 0:20:42.119 --> 0:20:46.639 more or fewer joints if it makes the operations work better. 0:20:47.000 --> 0:20:50.359 So that's something to think about, you know. And then 0:20:50.880 --> 0:20:54.360 walking would require shifting stability so that the robots can 0:20:54.400 --> 0:20:58.000 maintain itself with just one foot in contact with the ground, 0:20:58.400 --> 0:21:03.000 right like, suddenly points of contact have halved. If you're running, 0:21:03.040 --> 0:21:06.640 it's even harder because with running, at least the definition 0:21:06.720 --> 0:21:10.520 of running that roboticists use, there's a moment that may 0:21:10.560 --> 0:21:12.720 only last just for a split second, but there's a 0:21:12.760 --> 0:21:15.639 moment in which both of the robots feet are not 0:21:16.160 --> 0:21:19.480 touching the ground. So how do you achieve stability when 0:21:19.520 --> 0:21:25.160 your point of contact is continually interrupted? Jumping is even harder, right, 0:21:25.240 --> 0:21:28.879 because you're really leaving the ground then, and how do 0:21:29.000 --> 0:21:32.120 you ensure that landing you do so in a way 0:21:32.160 --> 0:21:36.640 that you maintain stability. So that ZMP was a huge deal. 0:21:36.680 --> 0:21:39.919 It still is a huge deal. Not all robot locomotion 0:21:40.119 --> 0:21:43.080 is centered around ZMP calculations, by the way, but a 0:21:43.119 --> 0:21:44.760 lot of it still is. So a lot of the 0:21:44.800 --> 0:21:48.800 work in bipedal robots, particularly in the seventies and eighties, 0:21:49.080 --> 0:21:52.520 involved calculating ZMP and keeping the robot within that zone 0:21:52.880 --> 0:21:57.000 while engineering movements. So calculating ZMP is one thing. Building 0:21:57.000 --> 0:22:00.400 a robot that can balance is another. Even building robot 0:22:00.440 --> 0:22:04.400 that's capable of static stability is no simple task. Static 0:22:04.400 --> 0:22:07.919 stability just means the robot is able to stand still 0:22:08.080 --> 0:22:10.680 and not fall over, and believe it or not, that's 0:22:10.720 --> 0:22:14.760 easier said than done. In nineteen seventy four, labs at 0:22:14.760 --> 0:22:18.000 the School of Science and Engineering at Waseda University in 0:22:18.080 --> 0:22:21.000 Japan started a project with the goal of building a 0:22:21.040 --> 0:22:26.960 stable bipedal robot. This project became known as Weibot wabot 0:22:27.720 --> 0:22:32.120 that stands for Waseda Robot. The labs created a new 0:22:32.200 --> 0:22:36.320 focus group within the laboratory system at the university. It's 0:22:36.320 --> 0:22:40.680 called the Bioengineering Group, and their first effort, the Waybot one, 0:22:41.000 --> 0:22:45.280 wasn't exactly something that you would mistake as a human being. 0:22:45.359 --> 0:22:48.400 It was not like a smooth humanoid robot. You would 0:22:48.480 --> 0:22:50.960 never look at it and think it was anything other 0:22:51.359 --> 0:22:53.439 than a robot. In fact, it looked kind of like 0:22:53.520 --> 0:22:57.040 a giant erector set. It was very much a big, blocky, 0:22:57.200 --> 0:23:02.240 metallic humanoid robot. So it had a limb control system, 0:23:02.320 --> 0:23:05.160 obviously very important if you're going to have a walking robot. 0:23:05.400 --> 0:23:08.199 It also had a primitive vision system. It even was 0:23:08.240 --> 0:23:11.479 able to converse in Japanese to a certain degree. They 0:23:11.520 --> 0:23:14.159 said that it had the in electrical capacity of like 0:23:14.160 --> 0:23:16.240 a one and a half year old Keep in mind 0:23:16.440 --> 0:23:19.840 this is the early nineteen seventies. It was tethered to 0:23:20.000 --> 0:23:22.959 computer systems and power systems. There was not yet a 0:23:23.000 --> 0:23:26.440 point where we had reached a miniaturization where you could 0:23:26.480 --> 0:23:29.240 have all that computing power, not to mention electrical power 0:23:29.480 --> 0:23:32.440 on board the robot itself. If you had done that, 0:23:32.640 --> 0:23:35.320 the robot would either need to be huge or would 0:23:35.320 --> 0:23:37.960 be carrying the biggest backpack you've ever seen in order 0:23:37.960 --> 0:23:41.600 to have all the computational and electrical power necessary to 0:23:41.640 --> 0:23:45.240 operate this thing. So, yeah, it was tethered. The Waybot 0:23:45.400 --> 0:23:49.560 was the first humanoid robot to achieve static stability, and 0:23:49.720 --> 0:23:54.200 later it would be the first digitally controlled anthropomorphic robot 0:23:54.280 --> 0:23:59.440 at all that was able to achieve dynamic stability, and 0:24:00.000 --> 0:24:03.160 statically stable means that the robot can remain balanced while 0:24:03.160 --> 0:24:07.240 standing still. Dynamically balanced refers to robots that are maintaining 0:24:07.280 --> 0:24:10.399 that stability while they are still in motion. Going from 0:24:10.520 --> 0:24:13.280 one to the other and back again is actually really hard. 0:24:13.480 --> 0:24:17.280 Like achieving one is hard, achieving the other one is 0:24:17.320 --> 0:24:21.120 also hard. Going back and forth between still and moving 0:24:21.280 --> 0:24:25.640 and maintaining balance is even harder. You know, remaining dynamically 0:24:25.680 --> 0:24:31.640 stable is often easier than going from dynamic to static, 0:24:32.119 --> 0:24:34.720 assuming that you know motions are smooth, and fast enough 0:24:34.720 --> 0:24:37.679 to counter the forces acting on the robot, because when 0:24:37.720 --> 0:24:42.080 you think about it, walking is really a series of falls. 0:24:42.520 --> 0:24:45.679 It's like you're falling and you're catching yourself over and 0:24:45.720 --> 0:24:48.520 over again. You move forward when you walk, not just 0:24:48.560 --> 0:24:51.359 by moving your legs. You know, you kind of lean 0:24:51.480 --> 0:24:54.119 forward into the walk as well, and for a moment 0:24:54.400 --> 0:24:57.480 it's as if you're falling forward and that you would 0:24:57.520 --> 0:25:00.280 face plant into the ground ahead of you. But of 0:25:00.280 --> 0:25:03.800 course you've moved your leg to catch yourself, and this 0:25:03.880 --> 0:25:08.919 process repeats, so you're propelling yourself forward by constantly almost 0:25:08.960 --> 0:25:12.560 falling but catching yourself over and over and over again. 0:25:12.800 --> 0:25:15.040 Now we do this without really thinking about it, like 0:25:15.080 --> 0:25:17.199