underactuated (fewer motors than degrees of freedom)
Developer - Kodlab
underactuated (fewer motors than degrees of freedom)
Developer - Kodlab
https://youtu.be/wvYthkpRFfk
The Penn Jerboa
Published on Mar 27, 2015
Quote:
The Penn Jerboa is a new underactuated (fewer motors than degrees of freedom) tailed bipedal robot platform in Kodlab that draws inspiration from jerboas or kangaroo rats, but at the same time, does not attempt to mimic their physiology or behavior. The robot is capable of quasistatic (using the tail as a strut) and dynamic balance (when the tail is in the air, the robot can run or hop but not stand), as well as agile transitional motions such as leaping and turning. The first behavior being explored is tail-energized planar hopping (using a boom to lock the robot to the sagittal plane). The technical report describes the construction of the machine, the development of this new use of a robotic tail, as well as the overarching control strategy of parallel composition of templates, which draws inspiration from and builds upon Marc Raibert's early work.
https://youtu.be/0p-ye6bSqbc
Tail-Assisted Leaping on Jerboa Robot
Published on Sep 23, 2015
Quote:
The Penn Jerboa showcases new leaping behaviors and demonstrates an innovative method of describing and categorizing these leaps across robot platforms.
Article "University of Pennsylvania Unleashes Robot Jerboa Upon the World"
by Evan Ackerman
April 16, 2015
Abstract:
This paper explores the design space of simple
legged robots capable of leaping culminating in new behaviors
for the Penn Jerboa, an underactuated, dynamically dexterous
robot. Using a combination of formal reasoning and physical
intuition, we analyze and test successively more capable
leaping behaviors through successively more complicated body
mechanics. The final version of this machine studied here
bounds up a ledge 1.5 times its hip height and crosses a
gap 2 times its body length, exceeding in this last regard the
mark set by the far more mature RHex hexapod. Theoretical
contributions include a non-existence proof of a useful class of
leaps for a stripped-down initial version of the new machine,
setting in motion the sequence of improvements leading to the
final resulting performance. Conceptual contributions include a
growing understanding of the Ground Reaction Complex as an
effective abstraction for classifying and generating transitional
contact behaviors in robotics.
https://youtu.be/8Vz-5esao7k
Analytically-guided design of a tailed bipedal hopping robot
Published on Jul 18, 2018
Quote:
We present the first fully spatial hopping gait of a 12 DoF tailed biped driven by only 4 actuators. The control of this physical machine is built up from parallel compositions of controllers for progressively higher DoF extensions of a simple 2 DoF, 1 actuator template. These template dynamics are still not themselves integrable, but a new hybrid averaging analysis yields a conjectured closed form representation of the approximate hopping limit cycle as a function of its physical and control parameters. The resulting insight into the role of the machine's kinematic and dynamical design choices affords a redesign leading to the newly achieved behavior.
2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2018)
Authors: Abdulaziz Shamsah, Avik De, Daniel E. Koditschek
This work was supported in part by AFRL grant FA865015D1845 (subcontract 669737-1) and in part by ONR grant \#N00014-16-1-2817, a Vannevar Bush Fellowship held by the last author, sponsored by the Basic Research Office of the Assistant Secretary of Defense for Research and Engineering.