Structural Identifiability and Discrete Symmetries

TL;DR

This paper explores how discrete symmetries influence the structural identifiability of control systems, providing a methodology to detect and analyze parameters affected by these symmetries.

Contribution

It introduces a novel approach focusing on discrete symmetries for structural identifiability analysis, contrasting with traditional continuous symmetry methods.

Findings

Discrete symmetries can cause parameters to be locally but not globally identifiable.

The methodology detects parameters involved in discrete symmetries.

Application to four case studies demonstrates the effectiveness of the approach.

Abstract

We discuss the use of symmetries for analysing the structural identifiability and observability of control systems. Special emphasis is put on the role of discrete symmetries, in contrast to the more commonly studied continuous or Lie symmetries. We argue that discrete symmetries are the origin of parameters which are structurally locally identifiable, but not globally. We exploit this fact to present a methodology for structural identifiability analysis that detects such parameters and characterizes the symmetries in which they are involved. We demonstrate the use of our methodology by applying it to four case studies.