Review of modelling and control of two-wheeled robots

In the past decade, there has been much more research in two-wheeled robots which actively stabilize themselves. Various models and controllers have been applied both to explain and control the dynamics of two-wheeled robots. We explore the methods which have been investigated and the controllers which have been used, first for balancing and movement of two-wheeled robots on flat terrain, then for two-wheeled robots in other situations, where terrain may not be flat, where there may be secondary objectives and where the robots may have additional actuators.