The system under investigation is the hydraulically driven autonomous large-scale combined legged and wheeled vehicle ALDURO. In this paper two comlete mechatronic simulation models, realized in the object-oriented programming language C++, will be presented. Both contain the mechanical system including an explicit solution of the kinematic loops. The first model is used as a basis for a model based motion control of the walking machine. the second, more detailed model, also includes a model of the ground contact and the dynamics of the complete hydraulic system. It used to test the model based controlle.