An “I Cant Decide What I Am” Robot

Most biomimetic robots are inspired by a single natural system.  An oak tree or an octopus.  A bat or a bunny.  But not more than one.

But, of course, robots have a deep (non-biomimetic) history of transforming.

This summer researchers at CalTech and Northeastern demonstrated a transformer that morphs to employ multiple bio-inspired mobility modes [2].  It even flies!

Cool.

The interesting thing is that this morphing is mainly done by repurposing various parts.  The wheels can be splayed to work as “legs”, and they are also propellers for quad coptering.

Pretty neat.

There are also some not-at-all-bio-mimetic modes. Obviously, there aren’t any Carbon-based copters on this planet.  But also the bot achieves “meerkat mode”, erect two wheeling, with the assistance of two wheel-fans for balance and leverage.  This is not how meerkats or anything does it.  (OK, maybe baby birds do something like this, I dunno.)

Achieving this flexibility is, of course, a design challenge.  The reason every wheeled vehicle doesn’t transform into a copter on occasion is that it is very hard to make things light enough to fly, yet strong enough to drive.  And, frankly, this morphing bot doesn’t do any of its tricks very well.  It’s slow, awkward, and probably very inefficient all around.  And don’t even ask about payload and range.

On the other hand, they show off how the morphing bot can do obstacle courses, switching modes to surmount barriers.

And this kind of multimode bot seems like just the thing for, say a Mars mission [1].  We can’t send 8 rovers, but maybe we can send one transformer rover. 

Pretty neat.

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1. Payal Dhar, This Robot Has All the Moves—Eight, to be Precise, in IEEE Spectrum – Robotics, July 3, 2023. https://spectrum.ieee.org/robot-animals
2. Eric Sihite, Arash Kalantari, Reza Nemovi, Alireza Ramezani, and Morteza Gharib, Multi-Modal Mobility Morphobot (M4) with appendage repurposing for locomotion plasticity enhancement. Nature Communications, 14 (1):3323, 2023/06/27 2023. https://doi.org/10.1038/s41467-023-39018-y

Robot Wedneday

More From the Bat Bot Folks

The Bat Bot folks have a great article in Science this month, summarizing the challenges of replicating the flight of bats in biomimetic robots.

As I have said before, this bot is just plain cool! (And it goes to show that quadcopters are hardly the only way to do UAV.)

The article explains the “ridiculously stupid” complexity of bat wings and flight. It’s just nuts.

Fig. 1 Functional groups in bat (photo courtesy of A. D. Rummel and S. Swartz, the Aeromechanics and Evolutionary Morphology Laboratory, Brown University). Enumerated bat joint angles and functional groups are depicted; using these groups makes it possible to categorize the sophisticated movements of the limbs during flight and to extract dominant DOFs and incorporate them in the flight kinematics of B2. The selected DOFs are coupled by a series of mechanical and virtual constraints.

The Bat Bot is inspired by, but does not fully copy bat anatomy. They have developed wings that are very recognizably “batty”, including a special membrane to emulate the flexible bat wings.

Besides the crazy anatomy, bat flight is nuts. They propel themselves with a complex “morphing wing flight”, which requires a stretch wing membrane. In addition, bats often flap relatively slowly, which introduces challenges for the control systems; “a flapping frequency that is lower than or equal to its natural body response; as a result, it is often affected by nonlinear inertial and aerodynamic artifacts.” ([2], p. 5)

Now that they have a working bat bot, they have been exploring how to imitate the amazing flying behavior of biological bats. They have worked out a “banking turn” and “dive maneuver”, but are still working on how to land in an upside down rooting position.

This project is a great example of biomimetic design. By attempting to replicate the anatomy and behavior of biological bats, they have discovered engineering principles that enable new and unique robot flight. At the same time, the robotic system has shed light on bat behavior and evolution, and may open the way for experiments that further elucidate the biology of bats.

Really cool.

(And don’t you think B2 should combine forces with Verity Studios, and get some bats into Cirque du Soleil?)

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1. Rebecca Hersher, Bat Bot’ Flying Robot Mimics ‘Ridiculously Stupid’ Complexity Of Bat Flight, in the two-way. 2017: NPR. http://www.npr.org/sections/thetwo-way/2017/02/03/513232878/bat-bot-flying-robot-mimics-ridiculously-stupid-complexity-of-bat-flight
2. Alireza Ramezani, Soon-Jo Chung, and Seth Hutchinson, A biomimetic robotic platform to study flight specializations of bats. Science Robotics, 2 (3) 2017. http://robotics.sciencemag.org/content/2/3/eaal2505.abstract

 

Robot Wednesday

Bat Bot 2 Again

The Bat Bot group at University of Illinois Urbana Champaign is making the B2 even more bat like and cooler. The latest developments will be reported in May at the International Conference on Robotics and Automation (ICRA) in Stockholm.

Preview videos indicates that they have covered the BB with very bat-like skin—it really, really looks like a bat!

They are also improving the behavior, implementing closed loop control logic for the complex twisty flappy bat flight. I don’t actually know, but I will bet that bats use closed loop neural control to fly, and it will ultimately be interesting to compare the Bat Bot to natural bats, to understand the essence of bat flight.

Nice work.

Upcoming Paper:

1. Ramezani, X. Shi, S.-J. Chung, and S. Hutchinson, “Bat Bot (B2), A Biologically Inspired Flying Machine,” Proc. IEEE International Conference on Robotics and Automation (ICRA), Stockholm, Sweden, May 16-21, 2016.

 

Robot Wednesday

Illini Bat Bot, B2

In an earlier post I noted the really cool Bat inspired flying robot from our local Aerospace Robotics and Control Lab.

Continuing development, they released a video showing the latest version of Bat Bot (B2), clad in a Silicone membrane that resembles natural bat wings.

The videos show that, at least some of the time, this device sure looks like a bat in flight!

Of course, there is much more to do, including working out how to navigate!

But this is a really nice job, and a great result so far.

 

Robot Wednesday

Cool Bat Robot

Readers of this blog know that I really like biomimetic and bio-inspired design in any field, including UAVs. If there is any domain where nature has much to teach us, it is flight. Fortunately, roboticists are on it, learning to emulate the tricks of fascinating biological flyers.

One of our local labs is having some success emulating the flight of bats. Seth Hutchinson and colleagues are reporting on “Lagrangian Modeling and Flight Control of Articulated-Winged Bat Robot” at International Conference on Intelligent Robots and Systems in Hamburg this week.

This robot system emulates the “articulated wing” seen in many species of bats, along with the easily recognized flapping propulsion. The investigators comment that bat’s flight is low powered and they maneuver in tight spaces, which are valuable features for many uses of UAVs.

Cool!

Nice work. I look forward to seeing more details on this.

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Conference Paper this week:

1. Ramezani, Alireza , Shi, Xichen, Chung, Soon-Jo, Hutchinson, Seth, “Lagrangian Modeling and Flight Control of Articulated-Winged Bat Robot” 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems, Sept 28 – Oct 03, 2015, Congress Center Hamburg, Hamburg, Germany

 

Robot Wednesday