walking robots dr. leonid paramonov course: ttk6 – robotics 13.09.2013
TRANSCRIPT
Walking Robots
Dr. Leonid Paramonov
Course: TTK6 – Robotics
13.09.2013
Talk overview
Review of state of the art in walking robots Current walking robot project at ITK NTNU (student
project opportunities)
Walking robots classification
“Quasi-static” humanoid robots or the ones based on typical topology of industrial robots
2 dimensional walkers Based on passive walking mechanisms Biologically inspired robots Dynamic multi-pedal robots
* the current tendency in the field is in slow merging of different types of walking robot concepts
Quasi-static topologyProbably above 90% of all existing walking robots and the
absolute majority of DIY robotics
Relying on static stability of the structure depending on position of the centre of mass of the robot above robot's footprint
In a sense the dynamical forces are not desired here because they mess up the stability (design conflict)
Coordinated motion of multiple DoF's
Difficulty in motion planning which is in many cases just pre-recorded trajectories
Recent advances in the field
Why industrial robot topology?
Typical design – rigid links with cylindrical joints as DoFs controlled by geared DC/brushless motors
Often the dynamical trajectory planning for industrial applications requires compensation of the dynamic forces to “free” the robot for a trajectory following task
Conceptual problems of this robot topology
The worst possible place for a torque actuator Effective inertia of the geared actuators
JE = n2 * J, where n is the gearbox ratio
Design - “exponential law”
Asimo, Honda
In development since 1980s
Very impressive recent developments like running, hopping on one and two feet
High power legs
by JSK Lab,
Tokyo University
Humanoid robots by Kawada Industries Inc.
Closely related to JSK Lab in University Tokyo
Viki humanoid
by SDU, Odense, Denmark
World champion in CoboCup 2002 free style competitions
Petman, Boston Dynamics
Atlas, Boston Dynamics
Is being currently developed for DARPA Robotics Challenge
2D “Pole walkers”
Spring Flamingo, MIT, Leg Lab
2D “Pole walkers”
Rabbit, Grenoble, France
2D “Pole walkers”
MABLE, University of Michigan
Passive walkers
Walking down a small inclination slope using potential energy
Passive walkers
Research passive walkers - energy efficient periodic gaits
Actuated walkers using mechanical principles close to passive ones (example “Ranger” marathon walker by Cornell University)
Biologically inspired dynamic walkers/runners (not only bipeds)
Elastic compliant actuators, biologically inspired mechanical
structures, dynamic periodic gaits
Boston Dynamics: Big Dog, RoboMule, Cheetah (fastest running robot on Earth)
Biologically inspired dynamic walkers/runners (not only bipeds)
The Big Dog robot
Biologically inspired dynamic walkers/runners (not only bipeds)
The RoboMule robot
Biologically inspired dynamic walkers/runners (not only bipeds)
The Cheetah robot
Biologically inspired dynamic walkers/runners (not only bipeds)
MIT Cheetah robot
Cheetah cub robot by EPFL
Walking robot project
Existing theoretical result for 2D walker
Walking robot project
2D “Pole walker”, 2 passive degrees of freedom, 1 actuator
Theoretical challenges
Nonlinear control of periodic motions Trajectory planning with ground collisions Controller design
Walking robot project
Design challenges
Purpose built for verification of a specific theoretical results Direct drive actuator without gear Integration Experiments