10.28.2009 - Hu on Snakes
- Biological diversity
- Static stability <-Most animals
- Average size: small (beetle size)
- Average legs: six
- Dynamic stability <-Few animals
- Static stability <-Most animals
- Snake movement
- Undulation
- Sidewinding
- Ratcheting
- Concertina
- Most experiments have snakes move through pegs
- Snakes can move without normal forces to lateral parts of body
- Snakes change gate based on the friction coefficient of the ground
- Model employed in the talk assumes sliding friction only (coulomb friction)
- Snake has very low inertia - when it stops moving it doesn't keep moving
- The dynamics of the snake were written in terms of the kinematics of the snakes assumed shape
- Speed is dependent on the ratio of forward-to-sidwards friction coefficient
- Since friction is the method of motion weight distribution is very important
- Snakes may also employ "active friction"