The present MSc thesis addresses the problem of modelling and controlling a four-wheel Skid-Steering Mobile Robot (SSMR) used for indoor trajectory tracking applications. The industries in need of a simple and robust mobile robot have long been drawn to SSMR solutions, but their underlying dynamic complexity has repeatedly hampered their true potential. As this category of robots is forced to skid in order to turn, they are characterised by complex wheel-ground interactions, which primarily exhibit as non-linear time-varying frictional forces. Such phenomena profoundly affect the behaviour of an SSMR and are responsible for unreliable dynamic models and inaccurate motion control system.