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The goal of the
Biomimetic Millisystems Lab is to harness features of
animal manipulation, locomotion, sensing, actuation,
mechanics, dynamics, and control strategies to radically
improve millirobot capabilities. Research in the lab
ranges from fundamental understanding of mechanical
principles to novel fabrication techniques to system
integration of autonomous millirobots. The lab works
closely with biologists to develop models of function
which can be tested on engineered and natural systems.
The lab's current research is centered on all-terrain
mobility using high power density, terrain coupling,
cooperation, and bioinspired principles.
Biomimetic Millisystems Lab Youtube channel
NEWS |
Multi-Layer Pouch Robots with Inkjet Masking Layers
(Oct. 2024)
A new
monolithic prototype fabrication method utilizes inkjet printing of a masking
ink layer, which prevents film bonding and thus defines inflatable regions.
Multi-layer inflatable pouches of any planar geometry can be created using
thermal fusing, with inter-layer connections and a minimum feature
resolution of 0.3 mm. The multi-layer fabrication process enables the
integration of pouches for bending actuation and structure, pneumatic
channels, and external port connections. This high level of integration enables
the fabrication of pouch robots with many independent DoFs, such as an planar manipulator
with 10 independent DoFs.
Y. You, C. Dai, E. Goldschmidt, and R.S. Fearing,
Advanced Materials Technologies, 2024, 2401052.
video: youtube
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Precision Robotic Leaping and Landing Using Stance-phase Balance
(May 2020)
We demonstrate targeted leaping as well as balanced
landing on a narrow foot with Salto-1P.
Accurate and reliable leaping and landing are achieved
by the combination of stance-phase balance control based on
angular momentum, a launch trajectory that stabilizes the robot
at a desired launch angle, and an approximate expression for
selecting touchdown angle before landing.
J.K. Yim, B.R.P. Singh, E.K. Wang, R. Featherstone and R.S. Fearing,
IEEE Robotics and Automation Letters, 2020
video: (youtube)
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Drift-Free Roll and Pitch Estimation for High-Acceleration Hopping
(May 2019)
Jumping robot SALTO estimates its own attitude, so it can jump
outside the motion capture lab for the first time!
Justin K. Yim, Eric K. Wang, and R.S. Fearing,
(ICRA 2019)
and
video from UCB News:
movie ,
video from ICRA19:
movie .
Congratulations to Justin and Eric for Best Student Paper
Award!
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OpenRoACH: A Durable Open-Source Hexapedal Platform with
Onboard Robot Operating System (ROS)
(May 2019)
OpenRoACH is a 15-cm 200-gram self-contained
hexapedal robot. The robot is fully open sourced,
can be fabricated with benchtop fast-
prototyping machines such as a laser cutter and a 3D printer,
and can be assembled by one person within two hours.
L. Wang, Y. Yang, G. Correa, K. Karydis, R. S. Fearing
(ICRA 2019)
and
CAD files, BoM, code
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Body Lift and Drag for a Legged Millirobot in Compliant Beam Environment
(May 2019)
Experiments with a tactile sensing shell on VelociRoACH
measured lift and drag forces while moving through
simulated grass. A shell-shape which reduces drag but increases
negative lift, such as the half-ellipsoid used, is suggested to be
advantageous for robot locomotion in this type of environment.
Can Koc, Cem Koc, Brian Su, C.S. Casarez and R.S. Fearing
(ICRA 2019)
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Precision Jumping Limits in Salto-1P from Flight-phase Control
(Oct. 2018)
We developed a deadbeat foot placement hopping
controller for an untethered monopedal robot, Salto-1P.
The robot demonstrated precise foot placement even
on trajectories with aggressive changes in speed, direction, and
height: in a random walk, its error standard deviation was 0.10
m. Foot placement precision is tightly limited
by attitude control accuracy, requiring attitude error less than
0.7 degrees for some tasks.
Justin K. Yim and R.S. Fearing,
(IROS 2018)
and
movie .
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Steering of an Underactuated Legged Robot through Terrain Contact
with an Active Tail
(Oct. 2018)
Two novel turning strategies using tail contact are
explored.
Tail drag turning provides comparable turning
maneuverability to differential drive turning gaits on carpet and
gravel surfaces. Tail impact turning can produce rapid point
turns on carpet, tarp, and gravel, but has a large variability
in turn angle and time to recover from the turn.
C.S. Casarez and R.S. Fearing
(IROS 2018)
and
movie .
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Learning Image-Conditioned Dynamics Models
for Control of Underactuated Legged Millirobots (Oct. 2018)
(Oct. 2018)
We present an approach for controlling a millirobot based on
learned neural network models. Using less than 17 minutes of data,
a predictive model of the robot's dynamics can be learned
that enables synthesis of effective gaits for steering on
specified terrain such as grass, styrofoam, or gravel.
A. Nagabandi, G. Yang, T. Asmar, R. Pandya,
G. Kahn, S. Levine, R.S. Fearing
(IROS 2018)
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Bidirectional, repulsive-/attractive-force
electrostatic actuators for a crawling milli-robot
(July 2018)
RAFA is a new thin-film electrostatic actuator which generates
electrostatic pressures up to 156 Pa in repulsion and 352 Pa in
attraction when operating at 0 to 1.2 kV. RAFAR, a 132 mg tethered
milli-robot, crawls at 0.32 mm/s with anisotropic friction feet.
E.W. Schaler, L. Jiang, C.Lee, and R.S.Fearing,
(MARSS 2018)
and
movie .
Congratulations to Ethan, Loren, and Caitlyn for Best Student Paper
Award!
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RSS 2018 Workshop on Design and Control of Small Legged Robots
(June 30, 2018)
Web Page
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Self-Engaging Spined Gripper with Dynamic Penetration and Release
for Steep Jumps
(May 2018)
A self-engaging gripper with spines was designed for a monopedal
jumping robot, to reduce slip and provide adhesion. The mechanism is
kinematically constrained to engage/disengage with leg
crouch/extension. The gripper enables jumping of a passive test
structure on penetrable inclines up to 60 degrees. J.S. Lee*,
M. Plecnik*, J. Yang, and R.S. Fearing,
(ICRA 2018) and
video
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Neural Network Dynamics Models for Control of Under-actuated Legged Millirobots
(Sep. 2017)
We present a learning based approach in which a model of the dynamics
is learned from data gathered by the millirobot, and that data is then
leveraged by an MPC controller. We show that with 17 minutes of random
data collected with the VelociRoACH millirobot, the VelociRoACH can
accurately follow trajectories at higher speeds and on more difficult
terrains than a differential drive controller.
A Nagabandi, G Yang, T Asmar, G Kahn, S Levine, R Fearing
arXiv:1711.05253 and
BAIR blog post
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Repetitive extreme-acceleration (14-g) spatial jumping with Salto-1P
(Sep. 2017)
Salto-1P uses aerodynamic thrusters and an
inertial tail to control its attitude in the air.
We present studies of extreme jumping locomotion in which the robot
spends just 7.7% of its time on the ground, experiencing accelerations
of 14 times earth gravity in its stance phase.
D.W. Haldane, J.K. Yim, and R.S. Fearing,
(IEEE IROS 2017) and
video.
Congratulations to Duncan and Justin
for IROS 2017 Best Paper Award!
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Dynamic Terrestrial Self-Righting with a Minimal Tail
(Sep. 2017)
A single degree of freedom tail gives VelociRoACH
the capability to dynamically
self-right. Open-loop
experiments on terrain with varying friction and roughness
show that VelociRoACH can dynamically self-right
in just 256 ms.
C. Casarez and R.S. Fearing,
(IEEE IROS 2017) and
video.
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High-rate turning using dual VelociRoACHes
(May 2017)
By connecting 2 robots by a compliant joint, the
front robot determines the direction of steering
and the rear robot generates thrust for high-rate turning.
Closed loop steering using an on-board gyro
is used to track a predefined path.
T. Seo, C.S. Casarez and R.S. Fearing,
(IEEE ICRA 2017) and
video
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Cooperative Inchworm Localization
(May. 2017)
A team movement strategy, referred to as inchworm, uses
picket robots which move ahead of the observer and act as temporary
landmarks for the observer to follow. This cooperative approach
employs a single Extended Kalman Filter (EKF) to localize the entire
heterogeneous multi-robot team.
B. Nemsick, et al.
(IEEE ICRA 2017) and
video
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Salto: Saltatorial Agile Locomotion on Terrain Obstacles
(Dec.
2016)
Through use of a specialized leg mechanism designed to enhance power
modulation, we constructed a jumping robot that achieved 78% of the
vertical jumping agility of a galago.
D.W. Haldane, M.M. Plecnik, J.K. Yim, and R.S. Fearing,
Science Robotics Dec. 2016
overview video
and jumps
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Modeling and Control of an Ornithopter for Diving
(Oct. 2016)
We identify piece-wise
affine linear models for
diving maneuvers in flapping winged flight.
These models are used to compute the reachability
sets that satisfy recovery conditions for safe diving. The point
within the dive to begin recovery was determined by checking the
current pose for inclusion in the backward reachable set.
2.2 meter dives were achieved at a success rate of 60
percent.
Rose et al. (IEEE/RSJ IROS Oct. 2016)
and movie
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Compound Foot for Increased Millirobot Jumping Ability
(Sep.
2016)
Bio-inspired compound feet with spines and foot pads improved a millirobot's jumping performance by 65%, bringing it close to a no-slip model.
J.S. Lee, R.S. Fearing, and K-J. Cho,
CLAWAR Sep. 2016
flea jump video
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Integrated
Jumping-Crawling Robot using Jumping Module (May.
2016)
A jumping module
attached to a small hexapedal crawler allows
controlled jumps of up to 2 meters height, while
the robot is capable of forward running. G-P.
Jung, C. Casarez, S-P. Jung, R.S. Fearing, and
K-J. Cho
(IEEE ICRA 2016) and
video SNU youtube
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Robotic
Folding of Ribbon Structures (May.
2016)
We propose the
concept of robotic ribbon folding for automatic
fabrication of robot structures. We demonstrate
robotic ribbon folding into 2D and 3D static
structures, and planar kinematic linkages
such as a simple non-crossing four-bar mechanism.
L. Wang, M.M. Plecnik, and R.S. Fearing, (IEEE
ICRA 2016).
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Step
Climbing Cooperation Primitives
(May. 2016)
We developed
primitives using quasi-static force analysis to
enable a pair of underactuated millirobots to
cooperatively climb a step. A tension controlled
tether provides a necessary additional degree of
freedom. C. Casarez and R. Fearing, (IEEE ICRA
2016) and
video. |
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Previous News
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Current
Research Projects
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Ambulating Robots
The goal of this
work is to develop high performance ambulating
milli-robots using minimal actuation and passive
stabilization mechanisms, combined with onboard
high level control.
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Folding
Prototyping of Meso- and Milli- Robots
Using laser cutting of composite materials, we
rapidly prototype small scale robots using flexure
technology. Example structures with dozens of joints
have been constructed. (Shown is autonomous
miniRoACH from 2008.)
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Past Research Projects
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Affiliations
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