Control system design for mechanical systems using contraction theory

Contraction theory is a recently developed control system tool based on an exact differential analysis of convergence. After establishing new combination properties of contracting systems, this paper derives new controller and observer designs for mechanical systems such as aircraft and underwater vehicles. The classical nonlinear strap down algorithm is also shown to be marginally contracting. The relative simplicity of the approach stems from its effective exploitation of the systems’ structural specificities.