On the influence of the parameter constraint on the stability of the poles and the discrimination capabilities of the stabilisation diagrams

This paper analyses the influence of the parameter constraint for modal parameter estimation (MPE) methods and its impact on the quality of the stabilisation diagram. It is shown that by a proper choice of the parameter constraint a distinction can be made between physical and mathematical poles based on the sign of the damping. As a result the quality of stabilisation diagrams can be improved. This approach can be applied for several well-known modal parameter estimation methods and the user can benefit from this. Several MPE applications in aerospace, automotive and civil engineering show the implication of the constraint and the specific advantages of obtaining an easy-to-interpret stabilisation diagram.