Modeling of the Multi-domain Steering System with Hybrid Dynamics for an Over-actuated Autonomous Vehicle

This paper presents modeling of a complex multidomain steering system, which consists of electrical, hydraulic, and mechanical physical subsystems. Moreover, it represents a hybrid system with continuous and discrete dynamics. The considered system is the steering system of an over-actuated heavy autonomous vehicle, which is used for container (size of 40 feet) transport in the port terminal. This Intelligent Autonomous Vehicle (IAV) can switch between three kinematic configurations based on combinations of its steering actuations. In this paper, the steering system is modeled using power-based graphical modeling approach called Bond Graph (BG). BG enables dynamic modeling of multi-domain systems directly from their physical structure. In addition, BG allows modeling of hybrid systems, i.e., Hybrid BG (HBG). The developed model is validated through co-simulation between Matlab/Simulink and a professional software for real-time simulation of vehicle dynamics called SCANeR Studio. Dynamics of IAV in SCANeR have been developed based on experimental data. The dynamic behavior of IAV is analyzed and compared in three different configurations.