Hi, my name is Jianzhe Gu.
I am a student from Morphing Matter Lab, Carnegie Mellon University.
Today, I'm going to introduce our world trust-based The Shape-Changing System with a
lightweight setup.
So trust is very common in architecture, you can see it everywhere.
And it has a unique advantage in mechanical strength and also has a very large volume
weight ratio. However, the structure is still static, you build it, you cannot change
it anymore. So researchers from Naza proposed a structure called Variable Geometry
Trust. In this case, it's still look like a truss structure, but every beam can change
the length by motor or or some other actuators.
And in that case, you can locally change the length of each beam and globally change the
geometry of the whole truss.
And they proposed a space crane arm.
This arm where it can do it can like expand a lot from a very compacted structure into a
very large structure, and it can do bending or twisting or elongating and do a lot of
complicated manipulation tasks in the space.
And nowadays there are people implementing this idea.
For example, people robotics, they use the hydraulic actuator or pneumatic actuator or
some motors to create this tetrahedron structure, and they can bring some model to
make sure the control algorithm is working well.
And they can't let it to local mode or manipulate objects.
And HCI people use it to create interactive sculptures, for example, this transformer.
There are a lot of plastic bottle, but some plastic bottle are replaced by a linear
actuator, and this linear actuator, together with a smart joint design, can actually the
whole structure to let a local mode or like turning around change the shape and I saw a
parametric robot is a kind of tetrahedron robot that's soft and can locomotion
untethered because the motors are embedded on the joints.
And as you can see, all these works are super cool and the beams they can freely and
independently elongate so that they can have a very large space to change the shape and
learn to do a lot of things, but with very basic units like Tetrahedron.
There are also some drawbacks here is that every beam can be individually controllable.
That means you need to.
You need that many actuators, for example, we need that many tubes to actuate that many
beams for pneumatic or hydraulic robots or for motor ones, you need that many motors.
So in that case, people could only build very simple robots like with two or three
adhesions. And yeah, the transformer have a lot of adhesions.
However, there are only three or four beams are actuated, while others are all passive,
so inherently still cannot change the shape that drastically.
So here we're trying to solve this problem, and we're trying to create a kind of robot
that can do a lot of motion.
It can has a really large deformation and have a lot of different geometry to change
from like shape, age or shape or shape seat.
But we also don't want there to be too many, actually or too many Cubans.
We want to minimize this actuation system.
So how can we make both happen?
And here is what we proposed or we introduced.
Is this truss robot?
It looks like just normal truss robot.
But actually, not every beamer are individually controlled.
Other actually, some of the beam are connected by the joints.
So that means if actually one of the beam, other beam will also be actuated.
And if you zoom in to see each actuator, it's just a syringe that can elongate based
on air pressure and to add more variables and more control ability.
We added three groove grooves onto the beam structure, and we also created a blocker
structure if you put this blocker onto the beam.
And now have you contract the beam, the beam will be stopped by the blocker.
And that means we change the contraction ratio of each beam.
Now here is an example.
If this is a tetrahedron and you contract it and were just uniformly be smaller and then
expand. But now, if you put some block structure on the beam, you can see the
blocker would stop the contraction and change the shape of the tetrahedron
drastically. However, here we can change the shape of each tetrahedron, but we can only
change once. There are only two shape like shape a contracted or should be elongated.
But whether we want more accountability, we wanted to have shape a bcd, but we don't want
each beam to be controlled.
What can we do?
So here we introduce a motorway joint design.
In this case, some of the beams are actually connected like all beams in green color.
They have the air connecting to each other, so we give air to one of the green beam.
All the others were elongated, the same thing for blue and the yellow beams and a
joined a very complicated cases on the right.
You can see if there are a lot of beams connecting to the same joint.
There will be a joint like this, and there is an algorithm to optimize the channel such
that the beams are correctly connected, but they are not intersecting with each other.
So like here on the right hand side, the yellow, blue and green there are multiple
beam in each of them.
But, but but each pair between these two channels, there is no air going through.
So let's see what will happen with this double tetrahedron.
The first, if the blue channel is activated, but others are like negative pressure, which
will happen. Yeah, the blue bars were elongated.
And now if we change it to.
Activating both the blue and the yellow channel, then the yellow party will also
elongate. And the same thing for the next case, if the yellow is disabled or green is
activated, it will elongate laterally and the yellow part will contract.
And eventually, if we close every channel or we remove the air pressure, the ants will go
back to the initial shape.
So as you can see, well, you only use like three channel, but we can create more more
than three different shapes.
And theoretically, you can create like two to the power of three kinds of different
shapes. So and this number will exponentially increase when you increase the
number of the beams or the number of the actuators.
So to create this structure, you can use a web based design tool.
In this tool, you can choose the correct setting and the create a structure
iteratively, and then you can choose the correct beams and assign a channel to them,
and you can choose when to activate which channel.
And based on the simulator, you can iteratively improve your control and your
channel and contraction.
Eventually, you can make a robot move or grab something or turn left or turn right.
So this is a lobster lobster.
Moving forward with both hands and the tail.
And this is a pure bug also trying to move forward.
And in this case, it's moving forward in like crawling way, like move the hands and
legs at the same time.
And here it's moving the leg like left and right.
Take a turn to move the leg to move forward.
And in this case, it can like turn left by only moving one one leg.
And then try to turn right with another leg.
Here is a fox, and this fox is happily moving forward with difference, here is its
air can contract here and can contract.
It can lower the body to go through some narrow space.
And here are some examples from our participants.
So there is a cloud, there is true flowers, and here are some
fish and some shape changing rocket and a four legged robot.