**Preface to "Combining Sensors and Multibody Models for Applications in Vehicles, Machines, Robots and Humans"**

Measuring and simulating sensors and physical models represent two ways of obtaining information from a dynamical system. Each of them has advantages and disadvantages, but the combination of both leads to more consistent results. This general idea can be particularized to mobile mechanical systems, also known as multibody systems. In this type of system, with popular examples including vehicles, machines, robots and humans, there is a tradition of using simplified models along with sensors to estimate the states, inputs and/or parameters of the system. However, in the last decade, research activity has been devoted to substituting the simplified models with detailed multibody models, which can be useful in some applications. Therefore, the aim of this Special Issue has been to gather contributions that illustrate the interest in this recent trend.

> **Javier Cuadrado, Miguel A. Naya** *Editors*
