In recent years, the ever-increasing interest in intelligent tyre technology has led to the formulation of different empirical models correlating deformation measurements provided by the sensors with tyre dynamics. In this paper, a real-time physical model, suitable for describing the dynamics of intelligent tyres based on measurements of strains and/or displacements of the tyre carcass, is presented. The proposed flexible ring model can reproduce the tyre dynamics for both concentrated and distributed forces by introducing a discrete approach that also allows to analyse the longitudinal dynamics of the tyre in real-time. The analytical description of the problem allows to obtain solutions in closed form and to quickly identify model parameters from experimental data. The comparison between the simulated results and the ones provided by indoor tests of two intelligent tyre concepts highlighted that the proposed tyre model can estimate with an acceptable precision both the carcass deformations and the forces acting on the tyre.