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[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.76,0:00:02.60,Default,,0000,0000,0000,,This is Pleurobot.
Dialogue: 0,0:00:03.40,0:00:07.02,Default,,0000,0000,0000,,Pleurobot is a robot that we designed\Nto closely mimic a salamander species
Dialogue: 0,0:00:07.04,0:00:08.44,Default,,0000,0000,0000,,called Pleurodeles waltl.
Dialogue: 0,0:00:09.24,0:00:11.50,Default,,0000,0000,0000,,Pleurobot can walk, as you can see here,
Dialogue: 0,0:00:11.52,0:00:13.56,Default,,0000,0000,0000,,and as you'll see later, it can also swim.
Dialogue: 0,0:00:14.28,0:00:16.47,Default,,0000,0000,0000,,So you might ask,\Nwhy did we design this robot?
Dialogue: 0,0:00:16.96,0:00:20.72,Default,,0000,0000,0000,,And in fact, this robot has been designed\Nas a scientific tool for neuroscience.
Dialogue: 0,0:00:21.40,0:00:23.90,Default,,0000,0000,0000,,Indeed, we designed it\Ntogether with neurobiologists
Dialogue: 0,0:00:23.92,0:00:25.82,Default,,0000,0000,0000,,to understand how animals move,
Dialogue: 0,0:00:25.84,0:00:28.60,Default,,0000,0000,0000,,and especially how the spinal cord\Ncontrols locomotion.
Dialogue: 0,0:00:29.56,0:00:31.26,Default,,0000,0000,0000,,But the more I work in biorobotics,
Dialogue: 0,0:00:31.28,0:00:33.66,Default,,0000,0000,0000,,the more I'm really impressed\Nby animal locomotion.
Dialogue: 0,0:00:33.92,0:00:38.22,Default,,0000,0000,0000,,If you think of a dolphin swimming\Nor a cat running or jumping around,
Dialogue: 0,0:00:38.24,0:00:39.82,Default,,0000,0000,0000,,or even us as humans,
Dialogue: 0,0:00:39.84,0:00:41.66,Default,,0000,0000,0000,,when you go jogging or play tennis,
Dialogue: 0,0:00:41.68,0:00:42.92,Default,,0000,0000,0000,,we do amazing things.
Dialogue: 0,0:00:43.88,0:00:48.02,Default,,0000,0000,0000,,And in fact, our nervous system solves\Na very, very complex control problem.
Dialogue: 0,0:00:48.04,0:00:51.14,Default,,0000,0000,0000,,It has to coordinate\Nmore or less 200 muscles perfectly,
Dialogue: 0,0:00:51.16,0:00:54.84,Default,,0000,0000,0000,,because if the coordination is bad,\Nwe fall over or we do bad locomotion.
Dialogue: 0,0:00:55.56,0:00:58.28,Default,,0000,0000,0000,,And my goal is to understand\Nhow this works.
Dialogue: 0,0:00:59.16,0:01:02.00,Default,,0000,0000,0000,,There are four main components\Nbehind animal locomotion.
Dialogue: 0,0:01:02.80,0:01:04.74,Default,,0000,0000,0000,,The first component is just the body,
Dialogue: 0,0:01:04.76,0:01:06.74,Default,,0000,0000,0000,,and in fact we should never underestimate
Dialogue: 0,0:01:06.76,0:01:10.24,Default,,0000,0000,0000,,to what extent the biomechanics\Nalready simplify locomotion in animals.
Dialogue: 0,0:01:10.92,0:01:12.38,Default,,0000,0000,0000,,Then you have the spinal cord,
Dialogue: 0,0:01:12.40,0:01:14.38,Default,,0000,0000,0000,,and in the spinal cord you find reflexes,
Dialogue: 0,0:01:14.40,0:01:17.86,Default,,0000,0000,0000,,multiple reflexes that create\Na sensorimotor coordination loop
Dialogue: 0,0:01:17.88,0:01:21.36,Default,,0000,0000,0000,,between neural activity in the spinal cord\Nand mechanical activity.
Dialogue: 0,0:01:22.00,0:01:24.98,Default,,0000,0000,0000,,A third component\Nare central pattern generators.
Dialogue: 0,0:01:25.00,0:01:28.90,Default,,0000,0000,0000,,These are very interesting circuits\Nin the spinal cord of vertebrate animals
Dialogue: 0,0:01:28.92,0:01:30.54,Default,,0000,0000,0000,,that can generate, by themselves,
Dialogue: 0,0:01:30.56,0:01:33.30,Default,,0000,0000,0000,,very coordinated\Nrhythmic patterns of activity
Dialogue: 0,0:01:33.32,0:01:35.70,Default,,0000,0000,0000,,while receiving\Nonly very simple input signals.
Dialogue: 0,0:01:35.72,0:01:36.94,Default,,0000,0000,0000,,And these input signals
Dialogue: 0,0:01:36.96,0:01:40.02,Default,,0000,0000,0000,,coming from descending modulation\Nfrom higher parts of the brain,
Dialogue: 0,0:01:40.04,0:01:42.74,Default,,0000,0000,0000,,like the motor cortex,\Nthe cerebellum, the basal ganglia,
Dialogue: 0,0:01:42.76,0:01:44.90,Default,,0000,0000,0000,,will all modulate activity\Nof the spinal cord
Dialogue: 0,0:01:44.92,0:01:46.38,Default,,0000,0000,0000,,while we do locomotion.
Dialogue: 0,0:01:46.40,0:01:49.62,Default,,0000,0000,0000,,But what's interesting is to what extent\Njust a low-level component,
Dialogue: 0,0:01:49.64,0:01:51.58,Default,,0000,0000,0000,,the spinal cord, together with the body,
Dialogue: 0,0:01:51.60,0:01:54.06,Default,,0000,0000,0000,,already solve a big part\Nof the locomotion problem.
Dialogue: 0,0:01:54.08,0:01:57.50,Default,,0000,0000,0000,,You probably know it by the fact\Nthat you can cut the head off a chicken,
Dialogue: 0,0:01:57.53,0:01:58.91,Default,,0000,0000,0000,,it can still run for a while,
Dialogue: 0,0:01:58.94,0:02:01.48,Default,,0000,0000,0000,,showing that just the lower part,\Nspinal cord and body,
Dialogue: 0,0:02:01.50,0:02:03.37,Default,,0000,0000,0000,,already solve a big part of locomotion.
Dialogue: 0,0:02:03.40,0:02:05.86,Default,,0000,0000,0000,,Now, understanding how this works\Nis very complex,
Dialogue: 0,0:02:05.88,0:02:07.18,Default,,0000,0000,0000,,because first of all,
Dialogue: 0,0:02:07.20,0:02:09.82,Default,,0000,0000,0000,,recording activity in the spinal cord\Nis very difficult.
Dialogue: 0,0:02:09.84,0:02:12.62,Default,,0000,0000,0000,,It's much easier to implant electrodes\Nin the motor cortex
Dialogue: 0,0:02:12.64,0:02:15.70,Default,,0000,0000,0000,,than in the spinal cord,\Nbecause it's protected by the vertebrae.
Dialogue: 0,0:02:15.72,0:02:17.54,Default,,0000,0000,0000,,Especially in humans, very hard to do.
Dialogue: 0,0:02:17.56,0:02:21.34,Default,,0000,0000,0000,,A second difficulty is that locomotion\Nis really due to a very complex
Dialogue: 0,0:02:21.36,0:02:24.42,Default,,0000,0000,0000,,and very dynamic interaction\Nbetween these four components.
Dialogue: 0,0:02:24.44,0:02:27.68,Default,,0000,0000,0000,,So it's very hard to find out\Nwhat's the role of each over time.
Dialogue: 0,0:02:28.88,0:02:32.62,Default,,0000,0000,0000,,This is where biorobots like Pleurobot\Nand mathematical models
Dialogue: 0,0:02:32.64,0:02:33.84,Default,,0000,0000,0000,,can really help.
Dialogue: 0,0:02:35.48,0:02:36.74,Default,,0000,0000,0000,,So what's biorobotics?
Dialogue: 0,0:02:36.76,0:02:39.50,Default,,0000,0000,0000,,Biorobotics is a very active field\Nof research in robotics
Dialogue: 0,0:02:39.52,0:02:41.98,Default,,0000,0000,0000,,where people want to\Ntake inspiration from animals
Dialogue: 0,0:02:42.00,0:02:44.46,Default,,0000,0000,0000,,to make robots to go outdoors,
Dialogue: 0,0:02:44.48,0:02:47.14,Default,,0000,0000,0000,,like service robots\Nor search and rescue robots
Dialogue: 0,0:02:47.16,0:02:48.36,Default,,0000,0000,0000,,or field robots.
Dialogue: 0,0:02:48.88,0:02:51.58,Default,,0000,0000,0000,,And the big goal here\Nis to take inspiration from animals
Dialogue: 0,0:02:51.60,0:02:53.94,Default,,0000,0000,0000,,to make robots that can handle\Ncomplex terrain --
Dialogue: 0,0:02:53.96,0:02:55.58,Default,,0000,0000,0000,,stairs, mountains, forests,
Dialogue: 0,0:02:55.60,0:02:57.62,Default,,0000,0000,0000,,places where robots\Nstill have difficulties
Dialogue: 0,0:02:57.64,0:02:59.70,Default,,0000,0000,0000,,and where animals\Ncan do a much better job.
Dialogue: 0,0:02:59.72,0:03:02.22,Default,,0000,0000,0000,,The robot can be a wonderful\Nscientific tool as well.
Dialogue: 0,0:03:02.24,0:03:04.86,Default,,0000,0000,0000,,There are some very nice projects\Nwhere robots are used,
Dialogue: 0,0:03:04.88,0:03:08.86,Default,,0000,0000,0000,,like a scientific tool for neuroscience,\Nfor biomechanics or for hydrodynamics.
Dialogue: 0,0:03:08.88,0:03:11.00,Default,,0000,0000,0000,,And this is exactly\Nthe purpose of Pleurobot.
Dialogue: 0,0:03:11.60,0:03:14.54,Default,,0000,0000,0000,,So what we do in my lab\Nis to collaborate with neurobiologists
Dialogue: 0,0:03:14.56,0:03:17.78,Default,,0000,0000,0000,,like Jean-Marie Cabelguen,\Na neurobiologist in Bordeaux in France,
Dialogue: 0,0:03:17.80,0:03:21.84,Default,,0000,0000,0000,,and we want to make spinal cord models\Nand validate them on robots.
Dialogue: 0,0:03:22.48,0:03:24.10,Default,,0000,0000,0000,,And here we want to start simple.
Dialogue: 0,0:03:24.12,0:03:26.10,Default,,0000,0000,0000,,So it's good to start with simple animals
Dialogue: 0,0:03:26.12,0:03:28.38,Default,,0000,0000,0000,,like lampreys, which are\Nvery primitive fish,
Dialogue: 0,0:03:28.40,0:03:30.90,Default,,0000,0000,0000,,and then gradually\Ngo toward more complex locomotion,
Dialogue: 0,0:03:30.92,0:03:32.18,Default,,0000,0000,0000,,like in salamanders,
Dialogue: 0,0:03:32.20,0:03:33.70,Default,,0000,0000,0000,,but also in cats and in humans,
Dialogue: 0,0:03:33.72,0:03:34.92,Default,,0000,0000,0000,,in mammals.
Dialogue: 0,0:03:35.88,0:03:38.26,Default,,0000,0000,0000,,And here, a robot becomes\Nan interesting tool
Dialogue: 0,0:03:38.28,0:03:40.22,Default,,0000,0000,0000,,to validate our models.
Dialogue: 0,0:03:40.24,0:03:43.26,Default,,0000,0000,0000,,And in fact, for me, Pleurobot\Nis a kind of dream becoming true.
Dialogue: 0,0:03:43.28,0:03:46.54,Default,,0000,0000,0000,,Like, more or less 20 years ago\NI was already working on a computer
Dialogue: 0,0:03:46.56,0:03:49.22,Default,,0000,0000,0000,,making simulations of lamprey\Nand salamander locomotion
Dialogue: 0,0:03:49.24,0:03:50.78,Default,,0000,0000,0000,,during my PhD.
Dialogue: 0,0:03:50.80,0:03:54.18,Default,,0000,0000,0000,,But I always knew that my simulations\Nwere just approximations.
Dialogue: 0,0:03:54.20,0:03:58.18,Default,,0000,0000,0000,,Like, simulating the physics in water\Nor with mud or with complex ground,
Dialogue: 0,0:03:58.20,0:04:00.86,Default,,0000,0000,0000,,it's very hard to simulate that\Nproperly on a computer.
Dialogue: 0,0:04:00.88,0:04:02.92,Default,,0000,0000,0000,,Why not have a real robot\Nand real physics?
Dialogue: 0,0:04:03.60,0:04:06.74,Default,,0000,0000,0000,,So among all these animals,\None of my favorites is the salamander.
Dialogue: 0,0:04:06.76,0:04:10.22,Default,,0000,0000,0000,,You might as why,\Nand it's because as an amphibian,
Dialogue: 0,0:04:10.24,0:04:13.10,Default,,0000,0000,0000,,it's a really key animal\Nfrom an evolutionary point of view.
Dialogue: 0,0:04:13.12,0:04:15.18,Default,,0000,0000,0000,,It makes a wonderful link\Nbetween swimming,
Dialogue: 0,0:04:15.20,0:04:17.10,Default,,0000,0000,0000,,as you find it in eels or fish,
Dialogue: 0,0:04:17.12,0:04:21.24,Default,,0000,0000,0000,,and quadruped locomotion,\Nas you see in mammals, in cats and humans.
Dialogue: 0,0:04:22.16,0:04:23.82,Default,,0000,0000,0000,,And in fact, the modern salamander
Dialogue: 0,0:04:23.84,0:04:26.22,Default,,0000,0000,0000,,is very close to the first\Nterrestrial vertebrate,
Dialogue: 0,0:04:26.24,0:04:27.78,Default,,0000,0000,0000,,so it's almost a living fossil,
Dialogue: 0,0:04:27.80,0:04:29.74,Default,,0000,0000,0000,,which gives us access to our ancestor,
Dialogue: 0,0:04:29.76,0:04:32.68,Default,,0000,0000,0000,,the ancestor to all terrestrial tetrapods.
Dialogue: 0,0:04:33.24,0:04:34.62,Default,,0000,0000,0000,,So the salamander swims
Dialogue: 0,0:04:34.64,0:04:37.14,Default,,0000,0000,0000,,by doing what's called\Nan anguilliform swimming gait,
Dialogue: 0,0:04:37.16,0:04:40.80,Default,,0000,0000,0000,,so they propagate a nice traveling wave\Nof muscle activity from head to tail.
Dialogue: 0,0:04:41.44,0:04:43.62,Default,,0000,0000,0000,,And if you place\Nthe salamander on the ground,
Dialogue: 0,0:04:43.64,0:04:45.98,Default,,0000,0000,0000,,it switches to what's called\Na walking trot gait.
Dialogue: 0,0:04:46.00,0:04:48.86,Default,,0000,0000,0000,,In this case, you have nice\Nperiodic activation of the limbs
Dialogue: 0,0:04:48.89,0:04:50.50,Default,,0000,0000,0000,,which are very nicely coordinated
Dialogue: 0,0:04:50.52,0:04:53.18,Default,,0000,0000,0000,,with this standing wave\Nundulation of the body,
Dialogue: 0,0:04:53.20,0:04:56.86,Default,,0000,0000,0000,,and that's exactly the gait\Nthat you are seeing here on Pleurobot.
Dialogue: 0,0:04:56.88,0:04:59.86,Default,,0000,0000,0000,,Now, one thing which is very surprising\Nand fascinating in fact
Dialogue: 0,0:04:59.88,0:05:04.02,Default,,0000,0000,0000,,is the fact that all this can be generated\Njust by the spinal cord and the body.
Dialogue: 0,0:05:04.04,0:05:06.04,Default,,0000,0000,0000,,So if you take\Na decerebrated salamander --
Dialogue: 0,0:05:06.06,0:05:08.08,Default,,0000,0000,0000,,it's not so nice\Nbut you remove the head --
Dialogue: 0,0:05:08.10,0:05:10.78,Default,,0000,0000,0000,,and if you electrically\Nstimulate the spinal cord,
Dialogue: 0,0:05:10.80,0:05:14.06,Default,,0000,0000,0000,,at low level of stimulation\Nthis will induce a walking-like gait.
Dialogue: 0,0:05:14.08,0:05:16.54,Default,,0000,0000,0000,,If you stimulate a bit more,\Nthe gait accelerates.
Dialogue: 0,0:05:16.56,0:05:18.46,Default,,0000,0000,0000,,And at some point, there's a threshold,
Dialogue: 0,0:05:18.48,0:05:21.02,Default,,0000,0000,0000,,and automatically,\Nthe animal switches to swimming.
Dialogue: 0,0:05:21.04,0:05:22.42,Default,,0000,0000,0000,,This is amazing.
Dialogue: 0,0:05:22.44,0:05:23.94,Default,,0000,0000,0000,,Just changing the global drive,
Dialogue: 0,0:05:23.96,0:05:25.70,Default,,0000,0000,0000,,as if you are pressing the gas pedal
Dialogue: 0,0:05:25.72,0:05:27.86,Default,,0000,0000,0000,,of descending modulation\Nto your spinal cord,
Dialogue: 0,0:05:27.88,0:05:30.88,Default,,0000,0000,0000,,makes a complete switch\Nbetween two very different gaits.
Dialogue: 0,0:05:32.44,0:05:35.02,Default,,0000,0000,0000,,And in fact, the same\Nhas been observed in cats.
Dialogue: 0,0:05:35.04,0:05:37.06,Default,,0000,0000,0000,,If you stimulate the spinal cord of a cat,
Dialogue: 0,0:05:37.08,0:05:39.30,Default,,0000,0000,0000,,you can switch between\Nwalk, trot and gallop.
Dialogue: 0,0:05:39.32,0:05:42.06,Default,,0000,0000,0000,,Or in birds, you can make a bird\Nswitch between walking,
Dialogue: 0,0:05:42.08,0:05:43.54,Default,,0000,0000,0000,,at a low level of stimulation,
Dialogue: 0,0:05:43.56,0:05:46.38,Default,,0000,0000,0000,,and flapping its wings\Nat high-level stimulation.
Dialogue: 0,0:05:46.40,0:05:48.42,Default,,0000,0000,0000,,And this really shows that the spinal cord
Dialogue: 0,0:05:48.44,0:05:50.86,Default,,0000,0000,0000,,is a very sophisticated\Nlocomotion controller.
Dialogue: 0,0:05:50.88,0:05:53.34,Default,,0000,0000,0000,,So we studied salamander locomotion\Nin more detail,
Dialogue: 0,0:05:53.36,0:05:56.46,Default,,0000,0000,0000,,and we had in fact access\Nto a very nice X-ray video machine
Dialogue: 0,0:05:56.48,0:06:00.06,Default,,0000,0000,0000,,from Professor Martin Fischer\Nin Jena University in Germany.
Dialogue: 0,0:06:00.08,0:06:02.66,Default,,0000,0000,0000,,And thanks to that,\Nyou really have an amazing machine
Dialogue: 0,0:06:02.68,0:06:05.14,Default,,0000,0000,0000,,to record all the bone motion\Nin great detail.
Dialogue: 0,0:06:05.16,0:06:06.42,Default,,0000,0000,0000,,That's what we did.
Dialogue: 0,0:06:06.44,0:06:09.62,Default,,0000,0000,0000,,So we basically figured out\Nwhich bones are important for us
Dialogue: 0,0:06:09.64,0:06:12.66,Default,,0000,0000,0000,,and collected their motion in 3D.
Dialogue: 0,0:06:12.68,0:06:15.38,Default,,0000,0000,0000,,And what we did is collect\Na whole database of motions,
Dialogue: 0,0:06:15.40,0:06:17.06,Default,,0000,0000,0000,,both on ground and in water,
Dialogue: 0,0:06:17.08,0:06:19.56,Default,,0000,0000,0000,,to really collect a whole database\Nof motor behaviors
Dialogue: 0,0:06:19.59,0:06:20.83,Default,,0000,0000,0000,,that a real animal can do.
Dialogue: 0,0:06:20.86,0:06:24.01,Default,,0000,0000,0000,,And then our job as roboticists\Nwas to replicate that in our robot.
Dialogue: 0,0:06:24.03,0:06:27.42,Default,,0000,0000,0000,,So we did a whole optimization process\Nto find out the right structure,
Dialogue: 0,0:06:27.44,0:06:30.10,Default,,0000,0000,0000,,where to place the motors,\Nhow to connect them together,
Dialogue: 0,0:06:30.12,0:06:33.00,Default,,0000,0000,0000,,to be able to replay\Nthese motions as well as possible.
Dialogue: 0,0:06:33.68,0:06:36.04,Default,,0000,0000,0000,,And this is how Pleurobot came to life.
Dialogue: 0,0:06:37.20,0:06:39.62,Default,,0000,0000,0000,,So let's look at how close\Nit is to the real animal.
Dialogue: 0,0:06:40.96,0:06:43.46,Default,,0000,0000,0000,,So what you see here\Nis almost a direct comparison
Dialogue: 0,0:06:43.48,0:06:46.18,Default,,0000,0000,0000,,between the walking\Nof the real animal and the Pleurobot.
Dialogue: 0,0:06:46.20,0:06:48.94,Default,,0000,0000,0000,,You can see that we have\Nalmost a one-to-one exact replay
Dialogue: 0,0:06:48.96,0:06:50.22,Default,,0000,0000,0000,,of the walking gait.
Dialogue: 0,0:06:50.24,0:06:52.84,Default,,0000,0000,0000,,If you go backwards and slowly,\Nyou see it even better.
Dialogue: 0,0:06:55.52,0:06:57.90,Default,,0000,0000,0000,,But even better, we can do swimming.
Dialogue: 0,0:06:57.92,0:07:00.94,Default,,0000,0000,0000,,So for that we have a dry suit\Nthat we put all over the robot --
Dialogue: 0,0:07:00.96,0:07:02.06,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:07:02.08,0:07:05.26,Default,,0000,0000,0000,,and then we can go in water\Nand start replaying the swimming gaits.
Dialogue: 0,0:07:05.28,0:07:08.62,Default,,0000,0000,0000,,And here, we were very happy,\Nbecause this is difficult to do.
Dialogue: 0,0:07:08.64,0:07:10.86,Default,,0000,0000,0000,,The physics of interaction are complex.
Dialogue: 0,0:07:10.88,0:07:13.30,Default,,0000,0000,0000,,Our robot is much bigger\Nthan a small animal,
Dialogue: 0,0:07:13.32,0:07:16.38,Default,,0000,0000,0000,,so we had to do what's called\Ndynamic scaling of the frequencies
Dialogue: 0,0:07:16.40,0:07:18.74,Default,,0000,0000,0000,,to make sure we had\Nthe same interaction physics.
Dialogue: 0,0:07:18.76,0:07:21.18,Default,,0000,0000,0000,,But you see at the end,\Nwe have a very close match,
Dialogue: 0,0:07:21.20,0:07:23.08,Default,,0000,0000,0000,,and we were very, very happy with this.
Dialogue: 0,0:07:23.48,0:07:25.70,Default,,0000,0000,0000,,So let's go to the spinal cord.
Dialogue: 0,0:07:25.72,0:07:28.02,Default,,0000,0000,0000,,So here what we did\Nwith Jean-Marie Cabelguen
Dialogue: 0,0:07:28.04,0:07:30.28,Default,,0000,0000,0000,,is model the spinal cord circuits.
Dialogue: 0,0:07:31.04,0:07:33.18,Default,,0000,0000,0000,,And what's interesting\Nis that the salamander
Dialogue: 0,0:07:33.20,0:07:34.82,Default,,0000,0000,0000,,has kept a very primitive circuit,
Dialogue: 0,0:07:34.84,0:07:37.50,Default,,0000,0000,0000,,which is very similar\Nto the one we find in the lamprey,
Dialogue: 0,0:07:37.52,0:07:39.50,Default,,0000,0000,0000,,this primitive eel-like fish,
Dialogue: 0,0:07:39.52,0:07:41.26,Default,,0000,0000,0000,,and it looks like during evolution,
Dialogue: 0,0:07:41.28,0:07:44.22,Default,,0000,0000,0000,,new neural oscillators\Nhave been added to control the limbs,
Dialogue: 0,0:07:44.24,0:07:45.66,Default,,0000,0000,0000,,to do the leg locomotion.
Dialogue: 0,0:07:45.68,0:07:47.86,Default,,0000,0000,0000,,And we know where\Nthese neural oscillators are
Dialogue: 0,0:07:47.88,0:07:50.14,Default,,0000,0000,0000,,but what we did was to make\Na mathematical model
Dialogue: 0,0:07:50.16,0:07:51.78,Default,,0000,0000,0000,,to see how they should be coupled
Dialogue: 0,0:07:51.80,0:07:54.74,Default,,0000,0000,0000,,to allow this transition\Nbetween the two very different gaits.
Dialogue: 0,0:07:54.76,0:07:57.32,Default,,0000,0000,0000,,And we tested that on board of a robot.
Dialogue: 0,0:07:57.68,0:07:58.88,Default,,0000,0000,0000,,And this is how it looks.
Dialogue: 0,0:08:06.92,0:08:09.94,Default,,0000,0000,0000,,So what you see here\Nis a previous version of Pleurobot
Dialogue: 0,0:08:09.96,0:08:13.06,Default,,0000,0000,0000,,that's completely controlled\Nby our spinal cord model
Dialogue: 0,0:08:13.08,0:08:14.68,Default,,0000,0000,0000,,programmed on board of the robot.
Dialogue: 0,0:08:15.28,0:08:16.50,Default,,0000,0000,0000,,And the only thing we do
Dialogue: 0,0:08:16.52,0:08:18.70,Default,,0000,0000,0000,,is send to the robot\Nthrough a remote control
Dialogue: 0,0:08:18.72,0:08:21.22,Default,,0000,0000,0000,,the two descending signals\Nit normally should receive
Dialogue: 0,0:08:21.24,0:08:22.84,Default,,0000,0000,0000,,from the upper part of the brain.
Dialogue: 0,0:08:23.48,0:08:26.18,Default,,0000,0000,0000,,And what's interesting is,\Nby playing with these signals,
Dialogue: 0,0:08:26.20,0:08:29.00,Default,,0000,0000,0000,,we can completely control\Nspeed, heading and type of gait.
Dialogue: 0,0:08:29.60,0:08:30.82,Default,,0000,0000,0000,,For instance,
Dialogue: 0,0:08:30.84,0:08:34.42,Default,,0000,0000,0000,,when we stimulate at a low level,\Nwe have the walking gait,
Dialogue: 0,0:08:34.44,0:08:36.42,Default,,0000,0000,0000,,and at some point, if we stimulate a lot,
Dialogue: 0,0:08:36.44,0:08:38.60,Default,,0000,0000,0000,,very rapidly it switches\Nto the swimming gait.
Dialogue: 0,0:08:39.48,0:08:41.70,Default,,0000,0000,0000,,And finally, we can also\Ndo turning very nicely
Dialogue: 0,0:08:41.72,0:08:45.24,Default,,0000,0000,0000,,by just stimulating more one side\Nof the spinal cord than the other.
Dialogue: 0,0:08:46.20,0:08:47.82,Default,,0000,0000,0000,,And I think it's really beautiful
Dialogue: 0,0:08:47.84,0:08:50.10,Default,,0000,0000,0000,,how nature has distributed control
Dialogue: 0,0:08:50.12,0:08:52.98,Default,,0000,0000,0000,,to really give a lot of responsibility\Nto the spinal cord
Dialogue: 0,0:08:53.00,0:08:56.66,Default,,0000,0000,0000,,so that the upper part of the brain\Ndoesn't need to worry about every muscle.
Dialogue: 0,0:08:56.68,0:08:59.22,Default,,0000,0000,0000,,It just has to worry\Nabout this high-level modulation,
Dialogue: 0,0:08:59.24,0:09:02.82,Default,,0000,0000,0000,,and it's really the job of the spinal cord\Nto coordinate all the muscles.
Dialogue: 0,0:09:02.84,0:09:06.36,Default,,0000,0000,0000,,So now let's go to cat locomotion\Nand the importance of biomechanics.
Dialogue: 0,0:09:07.08,0:09:08.34,Default,,0000,0000,0000,,So this is another project
Dialogue: 0,0:09:08.36,0:09:10.78,Default,,0000,0000,0000,,where we studied cat biomechanics,
Dialogue: 0,0:09:10.80,0:09:14.70,Default,,0000,0000,0000,,and we wanted to see how much\Nthe morphology helps locomotion.
Dialogue: 0,0:09:14.72,0:09:18.34,Default,,0000,0000,0000,,And we found three important\Ncriteria in the properties,
Dialogue: 0,0:09:18.36,0:09:19.68,Default,,0000,0000,0000,,basically, of the limbs.
Dialogue: 0,0:09:20.32,0:09:22.30,Default,,0000,0000,0000,,The first one is that a cat limb
Dialogue: 0,0:09:22.32,0:09:25.02,Default,,0000,0000,0000,,more or less looks\Nlike a pantograph-like structure.
Dialogue: 0,0:09:25.04,0:09:27.26,Default,,0000,0000,0000,,So a pantograph is a mechanical structure
Dialogue: 0,0:09:27.28,0:09:30.68,Default,,0000,0000,0000,,which keeps the upper segment\Nand the lower segments always parallel.
Dialogue: 0,0:09:31.60,0:09:34.70,Default,,0000,0000,0000,,So a simple geometrical system\Nthat kind of coordinates a bit
Dialogue: 0,0:09:34.72,0:09:36.54,Default,,0000,0000,0000,,the internal movement of the segments.
Dialogue: 0,0:09:36.56,0:09:39.62,Default,,0000,0000,0000,,A second property of cat limbs\Nis that they are very lightweight.
Dialogue: 0,0:09:39.64,0:09:41.50,Default,,0000,0000,0000,,Most of the muscles are in the trunk,
Dialogue: 0,0:09:41.52,0:09:44.42,Default,,0000,0000,0000,,which is a good idea,\Nbecause then the limbs have low inertia
Dialogue: 0,0:09:44.44,0:09:46.22,Default,,0000,0000,0000,,and can be moved very rapidly.
Dialogue: 0,0:09:46.24,0:09:50.06,Default,,0000,0000,0000,,The last final important property is this\Nvery elastic behavior of the cat limb,
Dialogue: 0,0:09:50.08,0:09:52.74,Default,,0000,0000,0000,,so to handle impacts and forces.
Dialogue: 0,0:09:52.76,0:09:55.10,Default,,0000,0000,0000,,And this is how we designed Cheetah-Cub.
Dialogue: 0,0:09:55.12,0:09:57.32,Default,,0000,0000,0000,,So let's invite Cheetah-Cub onstage.
Dialogue: 0,0:10:02.16,0:10:05.82,Default,,0000,0000,0000,,So this is Peter Eckert,\Nwho does his PhD on this robot,
Dialogue: 0,0:10:05.84,0:10:07.90,Default,,0000,0000,0000,,and as you see, it's a cute little robot.
Dialogue: 0,0:10:07.92,0:10:09.18,Default,,0000,0000,0000,,It looks a bit like a toy,
Dialogue: 0,0:10:09.20,0:10:11.26,Default,,0000,0000,0000,,but it was really used\Nas a scientific tool
Dialogue: 0,0:10:11.28,0:10:14.58,Default,,0000,0000,0000,,to investigate these properties\Nof the legs of the cat.
Dialogue: 0,0:10:14.60,0:10:17.22,Default,,0000,0000,0000,,So you see, it's very compliant,\Nvery lightweight,
Dialogue: 0,0:10:17.24,0:10:18.50,Default,,0000,0000,0000,,and also very elastic,
Dialogue: 0,0:10:18.52,0:10:21.30,Default,,0000,0000,0000,,so you can easily press it down\Nand it will not break.
Dialogue: 0,0:10:21.32,0:10:22.78,Default,,0000,0000,0000,,It will just jump, in fact.
Dialogue: 0,0:10:22.80,0:10:25.68,Default,,0000,0000,0000,,And this very elastic property\Nis also very important.
Dialogue: 0,0:10:27.16,0:10:29.06,Default,,0000,0000,0000,,And you also see a bit these properties
Dialogue: 0,0:10:29.08,0:10:31.48,Default,,0000,0000,0000,,of these three segments\Nof the leg as pantograph.
Dialogue: 0,0:10:32.28,0:10:35.06,Default,,0000,0000,0000,,Now, what's interesting\Nis that this quite dynamic gait
Dialogue: 0,0:10:35.08,0:10:36.98,Default,,0000,0000,0000,,is obtained purely in open loop,
Dialogue: 0,0:10:37.00,0:10:40.14,Default,,0000,0000,0000,,meaning no sensors,\Nno complex feedback loops.
Dialogue: 0,0:10:40.16,0:10:42.58,Default,,0000,0000,0000,,And that's interesting, because it means
Dialogue: 0,0:10:42.60,0:10:46.62,Default,,0000,0000,0000,,that just the mechanics\Nalready stabilized this quite rapid gait,
Dialogue: 0,0:10:46.64,0:10:50.82,Default,,0000,0000,0000,,and that really good mechanics\Nalready basically simplify locomotion.
Dialogue: 0,0:10:50.84,0:10:54.14,Default,,0000,0000,0000,,To the extent that we can even\Ndisturb a bit locomotion,
Dialogue: 0,0:10:54.16,0:10:55.82,Default,,0000,0000,0000,,as you will see in the next video,
Dialogue: 0,0:10:55.84,0:10:59.74,Default,,0000,0000,0000,,where we can for instance do some exercise\Nwhere we have the robot go down a step,
Dialogue: 0,0:10:59.76,0:11:01.38,Default,,0000,0000,0000,,and the robot will not fall over,
Dialogue: 0,0:11:01.40,0:11:02.98,Default,,0000,0000,0000,,which was a surprise for us.
Dialogue: 0,0:11:03.00,0:11:04.42,Default,,0000,0000,0000,,This is a small perturbation.
Dialogue: 0,0:11:04.44,0:11:06.86,Default,,0000,0000,0000,,I was expecting the robot\Nto immediately fall over,
Dialogue: 0,0:11:06.88,0:11:09.32,Default,,0000,0000,0000,,because there are no sensors,\Nno fast feedback loop.
Dialogue: 0,0:11:09.34,0:11:11.54,Default,,0000,0000,0000,,But no, just the mechanics\Nstabilized the gait,
Dialogue: 0,0:11:11.56,0:11:13.14,Default,,0000,0000,0000,,and the robot doesn't fall over.
Dialogue: 0,0:11:13.16,0:11:16.30,Default,,0000,0000,0000,,Obviously, if you make the step bigger,\Nand if you have obstacles,
Dialogue: 0,0:11:16.32,0:11:19.98,Default,,0000,0000,0000,,you need the full control loops\Nand reflexes and everything.
Dialogue: 0,0:11:20.00,0:11:22.94,Default,,0000,0000,0000,,But what's important here\Nis that just for small perturbation,
Dialogue: 0,0:11:22.96,0:11:24.46,Default,,0000,0000,0000,,the mechanics are right.
Dialogue: 0,0:11:24.48,0:11:26.58,Default,,0000,0000,0000,,And I think this is\Na very important message
Dialogue: 0,0:11:26.60,0:11:28.79,Default,,0000,0000,0000,,from biomechanics and robotics\Nto neuroscience,
Dialogue: 0,0:11:28.82,0:11:33.50,Default,,0000,0000,0000,,saying don't underestimate to what extent\Nthe body already helps locomotion.
Dialogue: 0,0:11:35.44,0:11:37.60,Default,,0000,0000,0000,,Now, how does this relate\Nto human locomotion?
Dialogue: 0,0:11:37.96,0:11:41.60,Default,,0000,0000,0000,,Clearly, human locomotion is more complex\Nthan cat and salamander locomotion,
Dialogue: 0,0:11:42.36,0:11:45.50,Default,,0000,0000,0000,,but at the same time, the nervous system\Nof humans is very similar
Dialogue: 0,0:11:45.52,0:11:47.10,Default,,0000,0000,0000,,to that of other vertebrates.
Dialogue: 0,0:11:47.12,0:11:48.58,Default,,0000,0000,0000,,And especially the spinal cord
Dialogue: 0,0:11:48.60,0:11:51.24,Default,,0000,0000,0000,,is also the key controller\Nfor locomotion in humans.
Dialogue: 0,0:11:51.76,0:11:54.18,Default,,0000,0000,0000,,That's why, if there's a lesion\Nof the spinal cord,
Dialogue: 0,0:11:54.20,0:11:55.70,Default,,0000,0000,0000,,this has dramatic effects.
Dialogue: 0,0:11:55.72,0:11:58.50,Default,,0000,0000,0000,,The person can become\Nparaplegic or tetraplegic.
Dialogue: 0,0:11:58.52,0:12:00.90,Default,,0000,0000,0000,,This is because the brain\Nloses this communication
Dialogue: 0,0:12:00.92,0:12:02.18,Default,,0000,0000,0000,,with the spinal cord.
Dialogue: 0,0:12:02.20,0:12:04.42,Default,,0000,0000,0000,,Especially, it loses\Nthis descending modulation
Dialogue: 0,0:12:04.44,0:12:06.36,Default,,0000,0000,0000,,to initiate and modulate locomotion.
Dialogue: 0,0:12:07.64,0:12:09.34,Default,,0000,0000,0000,,So a big goal of neuroprosthetics
Dialogue: 0,0:12:09.36,0:12:11.74,Default,,0000,0000,0000,,is to be able to reactivate\Nthat communication
Dialogue: 0,0:12:11.76,0:12:14.20,Default,,0000,0000,0000,,using electrical or chemical stimulations.
Dialogue: 0,0:12:14.84,0:12:17.78,Default,,0000,0000,0000,,And there are several teams\Nin the world that do exactly that,
Dialogue: 0,0:12:17.80,0:12:19.02,Default,,0000,0000,0000,,especially at EPFL.
Dialogue: 0,0:12:19.04,0:12:21.54,Default,,0000,0000,0000,,My colleagues Grégoire Courtine\Nand Silvestro Micera,
Dialogue: 0,0:12:21.56,0:12:22.80,Default,,0000,0000,0000,,with whom I collaborate.
Dialogue: 0,0:12:23.96,0:12:27.06,Default,,0000,0000,0000,,But to do this properly,\Nit's very important to understand
Dialogue: 0,0:12:27.08,0:12:28.82,Default,,0000,0000,0000,,how the spinal cord works,
Dialogue: 0,0:12:28.84,0:12:30.54,Default,,0000,0000,0000,,how it interacts with the body,
Dialogue: 0,0:12:30.56,0:12:33.04,Default,,0000,0000,0000,,and how the brain\Ncommunicates with the spinal cord.
Dialogue: 0,0:12:33.80,0:12:36.70,Default,,0000,0000,0000,,This is where the robots\Nand models that I've presented today
Dialogue: 0,0:12:36.72,0:12:38.62,Default,,0000,0000,0000,,will hopefully play a key role
Dialogue: 0,0:12:38.64,0:12:41.30,Default,,0000,0000,0000,,towards these very important goals.
Dialogue: 0,0:12:41.32,0:12:42.54,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:12:42.56,0:12:47.12,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:12:52.10,0:12:54.74,Default,,0000,0000,0000,,Bruno Giussani: Auke, I've seen\Nin your lab other robots
Dialogue: 0,0:12:54.76,0:12:57.22,Default,,0000,0000,0000,,that do things like swim in pollution
Dialogue: 0,0:12:57.24,0:12:59.70,Default,,0000,0000,0000,,and measure the pollution while they swim.
Dialogue: 0,0:12:59.72,0:13:00.94,Default,,0000,0000,0000,,But for this one,
Dialogue: 0,0:13:00.96,0:13:04.44,Default,,0000,0000,0000,,you mentioned in your talk,\Nlike a side project,
Dialogue: 0,0:13:05.64,0:13:06.86,Default,,0000,0000,0000,,search and rescue,
Dialogue: 0,0:13:06.88,0:13:09.06,Default,,0000,0000,0000,,and it does have a camera on its nose.
Dialogue: 0,0:13:09.08,0:13:11.58,Default,,0000,0000,0000,,Auke Ijspeert: Absolutely. So the robot --
Dialogue: 0,0:13:11.60,0:13:13.03,Default,,0000,0000,0000,,We have some spin-off projects
Dialogue: 0,0:13:13.05,0:13:16.50,Default,,0000,0000,0000,,where we would like to use the robots\Nto do search and rescue inspection,
Dialogue: 0,0:13:16.52,0:13:18.10,Default,,0000,0000,0000,,so this robot is now seeing you.
Dialogue: 0,0:13:18.12,0:13:21.30,Default,,0000,0000,0000,,And the big dream is to,\Nif you have a difficult situation
Dialogue: 0,0:13:21.32,0:13:24.94,Default,,0000,0000,0000,,like a collapsed building\Nor a building that is flooded,
Dialogue: 0,0:13:24.96,0:13:28.30,Default,,0000,0000,0000,,and this is very dangerous\Nfor a rescue team or even rescue dogs,
Dialogue: 0,0:13:28.32,0:13:31.22,Default,,0000,0000,0000,,why not send in a robot\Nthat can crawl around, swim, walk,
Dialogue: 0,0:13:31.24,0:13:34.42,Default,,0000,0000,0000,,with a camera onboard\Nto do inspection and identify survivors
Dialogue: 0,0:13:34.44,0:13:37.22,Default,,0000,0000,0000,,and possibly create\Na communication link with the survivor.
Dialogue: 0,0:13:37.24,0:13:40.82,Default,,0000,0000,0000,,BG: Of course, assuming the survivors\Ndon't get scared by the shape of this.
Dialogue: 0,0:13:40.84,0:13:44.14,Default,,0000,0000,0000,,AI: Yeah, we should probably\Nchange the appearance quite a bit,
Dialogue: 0,0:13:44.16,0:13:46.98,Default,,0000,0000,0000,,because here I guess a survivor\Nmight die of a heart attack
Dialogue: 0,0:13:47.00,0:13:49.54,Default,,0000,0000,0000,,just of being worried\Nthat this would feed on you.
Dialogue: 0,0:13:49.56,0:13:52.42,Default,,0000,0000,0000,,But by changing the appearance\Nand it making it more robust,
Dialogue: 0,0:13:52.44,0:13:54.50,Default,,0000,0000,0000,,I'm sure we can make\Na good tool out of it.
Dialogue: 0,0:13:54.52,0:13:56.81,Default,,0000,0000,0000,,BG: Thank you very much.\NThank you and your team.