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.
Neural Network Dynamics Models for Control of Under-actuated Legged Millirobots
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
BAIR blog post
Repetitive extreme-acceleration (14-g) spatial jumping with Salto-1P
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!
Dynamic Terrestrial Self-Righting with a Minimal Tail
A single degree of freedom tail gives VelociRoACH
the capability to dynamically
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
High-rate turning using dual VelociRoACHes (May.
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
Cooperative Inchworm Localization
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
Salto: Saltatorial Agile Locomotion on Terrain Obstacles
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
Compound Foot for Increased Millirobot Jumping Ability
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
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
(IEEE ICRA 2016) and
video SNU youtube
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
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
Force Sensing Shell
using a Planar Sensor
(Oct. 2015) We created a
low-cost, light-weight force-torque sensor using
photointerrupters with force sensivity of 17 mN.
This sensor can be used for body contact location
as well as environment drag forces. J. Goldberg
and R. Fearing, (IEEE IROS
2015) and video.
streamlined shapes in animals and robots enhance
traversability (June 2015) We found that both
cockroaches and simple robots rely on shell shape
to roll the body to allow traversal through a
field of compliant stalks. Chen Li, et al.
Bioinspiration and Biomimetics and
Launching of an Ornithopter with a Hexapedal Robot
(May 2015) We develop a
cooperative launching system for a 13.2 gram
ornithopter micro-aerial vehicle (MAV), the
H2Bird, by carrying it on the VelociRoACH. We
determine the necessary initial velocity and pitch
angle for take off using force data collected in a
wind tunnel and use the VelociRoACH to reach these
initial conditions for successful launch. Rose et
ICRA May 2015) video
Running beyond the
(May 2015) The X2-VelociRoACH
is a 54 gram experimental legged robot which was
developed to test hypotheses about running with
unnaturally high stride frequencies. It is capable
of running at stride frequencies up to 45 Hz, and
velocities up to 4.9 m/s, making it the fastest
legged robot relative to size. Haldane and Fearing
ICRA May 2015)
Anisotropic Leg Spines for Increased Traction
Collapsible leg spines found on insects and
spiders provide a passive mechanism for increased traction
while running over complex terrain. Spiny feet for VelociRoACH
reduced dimensionless Cost of Pulling by an order of magnitude
while robot speed while pulling load increased by 50%.
Lee and Fearing (IEEE ICRA May 2015)
Controllable Particle Adhesion (Feb. 2013) Controllable
adhesion to glass spheres with a magnetically
actuated synthetic gecko adhesive is demonstrated.
Results show sphere pull-off forces can be
increased 10-fold by changing the ridge
orientation via the external magnetic field, and
that the effective elastic modulus can be changed
from 65 kPa to 1.5 MPa.
movie of controllable adhesive
Gillies et al. Advanced Functional Materials, 2013
Bioinspired sensors and control strategies are being
developed for coordinated flight of multiple
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.)
We are developing a low cost (<$1000))
desktop factory which will allow users to
build millirobots from a kit of components.