Identification of a deterministic constant-affine state space model with known initial conditions

Constant-affine state space models arise naturally from the linearisation of nonlinear state space models at either on or off equilibriums. Therefore this model structure has a clear interpretation from the dynamical systems point of view and is closely related to model-based technologies such as model-based control. In this paper, the authors investigate some properties of this model structure and propose two system identification algorithms for the deterministic constant-affine state space model with known initial conditions. The first algorithm is based on a subspace identification algorithm, while the second is built on nonlinear least squares