|
|
Foundations of Robotics
Seminar, April 4, 2007
Time
and Place | Seminar Abstract1 | Seminar Abstract2 | Speaker
Appointments
ICRA 2007 Practice
Talks
Jonathan Hurst
NSH 1507
Refreshments 4:15 pm
Talk 4:30 pm
This paper discusses the design principles and
philosophy of the BiMASC, a biped with Mechanically
Adjustable Series Compliance which incorporates tuned mechanical leg springs. This
robot will be capable of dynamic running using mechanical leg springs, as well
as dynamic ballistic walking with human-like passive leg swing behavior. The BiMASC will enable the study of the role of both
controllable compliance in running and will serve as a test platform for
control strategies that utilize the leg springs and other natural dynamics of
the robot.
The mechanism is designed to behave in a dynamically "clean"
manner, such that relatively simple mathematical models will accurately predict
the robot's behavior. The availability of simple and accurate mathematical
models will facilitate the design of controllers, accurate simulations, and the
implementation of accurate model-based control on the robot.
|
A
Policy for Open-Loop Attenuation of Disturbance Effects Caused by Uncertain
Ground Properties in Running |
Outside of the laboratory, accurate models of ground impact
dynamics are either difficult or impossible to obtain. Instead, a rigid ground
model is often used in gait and controller design, which simplifies the system
model and allows attention to remain focused on other
aspects of running. In real-world terrain this simplification may overlook
important dynamic effects. Immediately following
a foot touchdown event, sensitivity to ground stiffness is at its highest and
at the same time the accuracies of state
estimates are at their lowest. Even if ground
stiffness is known and state estimates are accurate, actuator bandwidth
limitations make immediate compensation difficult. Taking inspiration from
nature, we propose a novel solution to attenuate the effects of unexpected ground
stiffness changes using a unified control system comprised of hardware passive
dynamics and open-loop software control policies.
For appointments, please contact Jonathan
Hurst.
The Robotics Institute is part of the School of Computer Science, Carnegie Mellon University.