Short Videos

Andy Ruina explains how bicycles balance. (8 min) 2011, part of publicity for the Zero-trail, Zero angular momentum bicycle.

A bicycle in zero gravity is unrideable (The bricycle). (3 min) 2014

Cornell Ranger 2011 - Marathon Walking Robot. (4 min) Cornell Ranger, a 4-legged Biped Robot, walks 40.5 miles on a single battery charge.

Powered Biped With Knees. (2 min) A 3D, efficient, powered bipedal walking robot developed by Steve Collins.

Passive Dynamic Walking. (3 min) A collection of passive dynamic walkers. Each walker walks down a slight incline powered only by gravity.

Passive Dynamic TinkerToy Walker. (1 min) Tinker Toy passive dynamic walker cannot stand upright but can stably walk downhill. It is powered only by gravity.

Stable and efficient bipedal robot platform - NRI PI Meeting 2016. (2 min) Information about Tik-Tok, a walking robot being developed at Cornell

Longer Talks 

Passive Dynamics is a good basis for walking control. Not. (~70 minutes + 60 minutes of questions) IIsc Feb 2, 2022  (Evolved version of above below)
Gliders, bicycles and walking robots. (1hr, 11 min) Andy Ruina, Carnegie Mellon Robotics Seminar, 2012  (Old version of the same talk as above)

Non-holonomic mechanics and Rotation with Zero Angular Momentum (The Falling cat)
(80 min total)   as deliverred to the Indian  Centre for Theoretical Sciences (ICTS) in Bangalore on April 25, 2022.  Here it is, in two parts, from a class-room version in Fall 2020.     Part I,     Part II

A critique of Induced Acceleration Analysis. (15 min) Andy Ruina, World Congress in Biomechanics, Boston, 2014 
[Also see Mechanics for Biomechanics, part II therein, below]

Mechanics for biomechanics, A. All of Mechanics, B. Induced Accelerations, C. Collisions  (40-min), Andy Ruina, ISB/ASB 2019 Calgary

Passive Dynamics needs accurate complex modeling, controlled dynamics often doesn't. (24 min) Andy Ruina, Dynamic Walking Conference 2018, Pensacola.

Why don't bicycles fall down?  (80 min) Ithaca Science Center, June 2019

Sliding with infinite friction  (40 min)  Banff 2014 Contact mechanics conference


Intermediate Dynamics, MAE 4730/5730 Fall 2020  42 lectures

Applied Dynamics,
MAE 4710/5710   Spring 2020
          First 21 Lectures on Panopto
          Final 18 lectures on Cornell's VOD (Video on Demand). 
Sortws by creation date, ascending,

Sophomore Dynamics,
MAE 2030   Spring 2021  40 lectures  (same as below, some Covid hybrid-class video problems, early lectures are bad)
Dynamics Spring 2013, MAE 2030   28 lectures  (Older, but better video than above)
   also on YouTube

Statics and Strength of Materials,
MAE 2020   Fall 2010   41 lectures

Linear Algebra,
MAE Math 2940     Spring 2009   41 lectures

Intro to Engineering for Freshman,
MAE 1170    28 Lectures

Miscellaneous video on YouTube

Disorganized and largely boring