Cats are known for an uncanny ability to land on their feet. This project explores this phenomenon, known as the "cat-righting reflex". It was completed for ME/BIOE 485: Modeling and Simulation of Human Movement, a course at Stanford University.

From a research perspective, we aim to answer two questions: (1) When falling upside down, what control strategies does a cat use to flip itself over and land on its feet? (2) What is the minimum model of a cat that will flip in a biologically realistic manner? For example, can the cat flip without being able to twist its spine? We begin to answer these questions using dynamic optimization and 'step-wise' model creation. The modeling and optimization source code is available for download.

In addition to these basic research questions, we believe that the cat-flipping problem provides an ideal framework for learning and teaching OpenSim. For this reason, we have compiled simplified versions of our modeling and optimization code. While this code is also available for download here, it is laid out in the form of an instructional tutorial on our Confluence webpage, which also contains a more detailed description of the project and our results.

Here is a short video overview of the project: