Delta-Modulation Coding Redesign for Feedback-Controlled Systems

Carlos Canudas de Wit (1) , Fabio Gomez Estern (2) , Francisco Rubio (2)

1 NECS - Networked Controlled Systems
2 ISA - Department of Automatic Control and Systems Engineering [Sevilla]

This paper investigates the closed-loop properties of the differential coding scheme known as Delta-modulation (Δ-M) when used in feedback loops within the context of feedback controlled systems. We propose a new modified scheme of the original form of the Δ-M algorithm which is better suited for applications where the sensed information is used in feedback. A state feedback controller is implemented with the state estimated by a predictor-based differential decoder. Stability of the resulting closed-loop system (controller-coder-decoder) is studied. These properties (stability and performance) depend on the quantization parameter Δ, which is assumed constant in the first part of this paper. In a further step, parameter Δ is made adaptive, by defining an adaptation law exclusively in terms of information available at both the transmitter and receiver side.With this approach both stability and performance is improved.

Keywords: Networked controlled systems

Domains: Automatic

Carlos Canudas de Wit, Fabio Gomez Estern, Francisco Rubio. Delta-Modulation Coding Redesign for Feedback-Controlled Systems. IEEE Transactions on Industrial Electronics, 2009, 56 (7), pp.2684-2696. ⟨10.1109/TIE.2009.2020079⟩. ⟨hal-00394981⟩