The Internal Model Principle of Regulator Theory on Differentiable Manifolds

Abstract Some concepts embodied in the Internal Model Principle, formulated for linear regulators, can be extended to nonlinear differentiable systems. Reference signals generated by an exosystem, or dynamic model of the “outside world”, induce a subflow, the endomorph, in the overall regulator dynamics. Sufficient conditions are presented for the uniqueness, smoothness and global attraction of the endomorph. With certain assumptions, the controller is shown to have an internal model in the case of step reference signals and for a more general exosystem with feedback of the regulated variable to the controller.