This repository stores the analysis codes and physical backgrounds of my final project for the Stanford ME303 course (Winter 2017): Biomechanics of Flight. All material can be freely distributed with proper citation of this repository: https://github.com/Mipanox/ME303.
The project aims at exploring birds' behavior in landing, in particular the decelaration phase of an american avocet and a northern shoveler. In the videos (or on Nimia: avocet; shoveler), the two birds exhibit quite distinct ways of braking: The avocet uses its wings as a "parachute" whereas the shoveler water-skies and in the same time flaps the wings back-and-forth. Simple models are applied to describe the physics behind the behavior.
(Note: As of this writing the author has not included any conclusion remarks in any of the notebooks. Will be there soon)
The extracted kinematics of representatitve parts of the body motions (e.g. wings, tails, torso) is shown here. This notebook includes a brief overview of the videos, some crude calibrations, and then presents the smoothed kinematic curves: for instance the bulk velocity variation with time.
In this notebook the simplified models adopted in the simulation ale explained. Some qualitative descriptions of the assumptions are made, but refer to the estimates for justification (or not).
From the kinematics, it is possible to retrieve useful quantities to be thrown into the models. This is illustrated here.
The whole process of landing is modeled by three mechanisms: (1) Steady flight, (2) parachuting, and (3) back-and-forth flapping plus water-skiing. Based on the assumptions, the birds are fully characterized by point masses, (half-)elliptical wings, and flat plates for the feet, with certain properties inferred from the kinematics/biology. The codes simulate the forces and powers that would be generated for the modelled "artificial" birds. Comparisons with observations are also conducted and examined in each notebook.