Coupled Rigid Bodies, Impulsive Dynamics, Applications - Trap Jaw Ants, Leaping Lizards, Falling Cat

Explore advanced dynamics applications in this 55-minute lecture covering coupled rigid bodies, impulsive dynamics, and fascinating biological systems. Delve into the unusual behavior of rolling and spinning bodies, multi-rigid body systems like the acrobot, and conservation of angular momentum with examples ranging from astronaut reorientation to how cats land on their feet. Examine gyro-stabilization in ships and spacecraft, impact dynamics in passive dynamic walking and jumping toys, and the ballistic jaw propulsion of trap-jaw ants. Conclude with an analysis of continuous systems with changing geometry, such as flying snakes, modeled as quasi-rigid bodies. Gain insights into the intersection of physics and biology, with potential applications in robotics and engineering design.

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Introduction of topics.
Unusual behavior of rolling and spinning bodies, like the tippe top and a spinning egg.
Coupled, multi-rigid body systems, such as the acrobot (acrobat robot on the high bar).
Conservation of angular momentum and interesting applications, such as astronaut reorientation in space ("Elroy's beanie"), tail-assisted pitch control of jumping lizards (suggesting the use of tails for robots), how cats land on their feet, and pitch control of cars in a jump off a ramp. The jumping lizards material is from http://doi.org/10.1038/nature10710.
Gyro-stabilization of ships (watercraft rocking due to waves) and control momentum gyroscopes for spacecraft. The company that makes the ship-stabilizing gyro is https://www.seakeeper.com.
Impact dynamics or impulsive dynamics, instantaneous dynamics vs. continuous dynamics. Applications include passive dynamic walking (of a simple compass bipedal walker), jumping popper toy (quick release of stored elastic energy), and ballistic jaw propulsion of trap-jaw ants ("ejection seat"). More about trap-jaw ants from Sheila Patek's paper: https://www.pnas.org/content/pnas/103/34/12787.full.pdf.
Continuous systems of changing geometry modeled as quasi-rigid bodies (that is bodies with time-varying geometry) with time-varying moment of inertia, e.g., the flying snake. More about flying snake modeling: https://youtu.be/0PQ1_XpjBso.