Landing Trajectory Planning Method for Amphibious Platforms in Complex Terrain Environments

Land and air amphibious robots with excellent mobility and endurance performance are becoming the focus of research in the field of robotics. In order to give full play to the maneuverability of land-air amphibious robots, it is necessary to perform tasks in the environment of unstructured ground and multi-dimensional obstacles in the air. Existing methods are difficult to solve the problems of obstacle avoidance and multi-constraint optimization of landing trajectories of land-air amphibious robots in complex terrain environments. In this paper, an improved Informed RRT* algorithm is proposed for the front-end path generation of the planner, and an unconstrained optimization problem equivalent to the multi-constraint problem is presented. A smooth, safe and dynamically feasible landing trajectory can be obtained by using the L-BFGS optimization algorithm for spatio-temporal joint optimization. Simulation experiments were carried out based on RotorS in the environment constructed by Gazebo. The experimental results showed the effectiveness of the proposed method. The landing trajectory of the unmanned platform met many constraints such as actuator and obstacle avoidance, and it could land smoothly and safely on uneven terrain.