ABSTRACT
Differential flatness is a natural idea associated with under-determined systems of differential equations. It represents the possibility of completely parameterizing every system variable in terms of a privileged finite set of “free” variables in the system. In order to understand the basic features of flatness, consider a system of n linear algebraic equations in n + m unknowns ξ = (x 1, …, x n , x n+1, …, x n+m ) = (x, x n+1, …, x n+m ) = (x, f), written as A x + B f = 0 , B ≠ 0 , r a n k [ A , B ] = n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315214658/437aa861-473c-4665-9f16-73fe709d8058/content/eq1.tif"/>
