NMPC for Trajectory Tracking of Hybird Terrestrial-Aerial Vehicles with Collision Avoidance

In recent years, researches on Hybrid Terrestrial-Aerial Vehicles (HTAVs) have received a lot of attention. However, most of the existing researches focus on achieving basic motion control in both modes, thus neglecting the situation of encountering obstacles during motion. To fill this research gap and achieve accurate trajectory tracking with collision avoidance, we proposes the use of Nonlinear Model Predictive Control (NMPC). In this paper, we firstly focus on passive-wheeled HTAVs as the target platform. Subsequently, we introduce distance constraint function and dynamics models for both aerial and terrestrial modes, along with three motion constraints specific to the terrestrial mode. Then we designed the NMPC controller base on distance constraint function and the dynamics models for each mode, incorporating the motion constraint in the terrestrial controller to ensure smooth movement on the ground. At the end of this paper, we conduct simulation experiments to evaluate the effectiveness of trajectory tracking. The results of simulations demonstrate that regardless of the mode, the HTAV achieves a relatively high tracking accuracy and avoid collision when following a nonlinear trajectory with fixed initial position and orientation. Additionally, the position error converges rapidly and exhibits minimal fluctuation, highlighting the significant role played by the added constraints in control.