Falling cat robot lands on its feet

Abstract

Cats are renowned for their ability to always land on their feet. When their body is dropped with no initial net angular momentum, they are able to rotate in the air using a variety of mech- anisms, including the use of a variable dier- ence between the moment of inertia of the front and back portions of their body due to the mo- tion of their legs. The aim of this project is to build a robotic falling cat than can right itself in the air not dissimilar in appearance and mech- anism to a biological cat. This paper describes the rst steps of creating a simplied model and designing a simulation to demonstrate the mechanism of a prototype. Theory is presented to calculate input torques to achieve rotation from any drop angle or (suciently large) drop height, and SimMechanics is used to verify and simulate the model.