"Robotics company Boston Dynamics has a new four–legged addition to its family: a 160–pound quadruped named Spot...
We know from Spot's reaction to that kick that he can dynamically correct his stability–behavior that's modeled after biological systems. From what Couzin can tell, the robots' collective movement is an organic outgrowth of that self–correction. When the two Spots collide at the 1:25 mark, they're both able to recover quickly from the nudge and continue on their route up the hill. 'But the collision does result in them tending to align with one another (since each pushes against the other),' Couzin wrote in an email. 'That can be an important factor: Simple collisions among individuals can result in collective motion.'
In Couzin's research on locusts, for example, the insects form plagues that move together by just barely avoiding collisions. 'Recently, avoidance has also been shown to allow the humble fruit fly to make effective collective decisions,' he wrote.
It doesn't look like Spot is programmed to work with his twin brothers and sisters–but that doesn't matter if their coordination emerges naturally from the physical rules that govern each individual robot. Clearly, bumping into each other isn't the safest or most efficient way to get your robot army to march in lock step, but it's a good start. And it's relatively easy to imagine several Spots working together in organized ways if the LIDAR sensors fitted on their 'heads' were programmed to create avoidance behaviors–like those locusts–rather than simply reacting to collisions.
Spot's life–like motions are uncanny, but when you add this emergent, collective behavior–which can sometimes be unpredictable–the possibilities get downright scary. Will Spot's group dynamics stop at the point of swarming like locusts? (Ominous.) Will they cluster into self–protecting balls like sardines? (Less so.) Or could they end up as smart and responsive as humans?
Couzin goes so far as to call this bump–and–grind between Spots One and Two a social interaction. 'No matter how primitive, there's no doubt that these interactions could enhance the decision–making capabilities of such robots when they must make their own, autonomous, decisions in an uncertain world,' he wrote. We'll just have to hope that decision–making involves not trampling us when a pack of Spots starts stampeding like wildebeest."
(Neel V. Patel, 11 February 2015 Wired News)
"Animating animals is usually fun, but can often be complicated and technical. Figuring out what to do with all those legs can really trip up an animator. We can animate human–shaped characters a lot easier than multi–legged beasts because we have an intuitive knowledge of the way bipeds move.
It is easy for an animator to act out a motion when the character moves like us; feeling the action 'in the body' helps us understand how to animate it. So what happens when the character is a quadruped and you don't have that intuitive feel at your disposal? How do you make that movement believable? Suitable reference and a sophisticated media player is the place to start.
Luckily for the animation community, there is a wealth of reference material that can help. I'll walk you through my process for animating quadruped locomotion and share classic references that will help you deconstruct the fundamentals of the four gaits: walk, run, trot and gallop. I'll also share an example of my own 3D walk animation and offer technical tips for creating believable quadruped locomotion cycles."
(Cathy Feraday Miller, Gamasutra)
Fig.1 Richard Williams, uploaded by "animan1999" on 25 Aug 2009, YouTube.
Fig.2 Richard Williams, uploaded by "animan1999" on 1 Sep 2009, YouTube.