Optimization-based Trajectory Planning for Reconfigurable Unmanned Vehicle Units: A Single- Alxe and Dual-Wheel Configuration

The development of land-reconfigurable transport equipment(LRTE) has given rise to a reconfigurable unmanned vehicle unit(RUVU) with the special configuration: Single-Alxe and Dual-Wheel Vehicles(SADWVs). These have the capability for independent drive and steer of all wheels. Self-reconfigurable docking is at the core of land-reconfiguration technology, and the motion planning for SADWV is also the key to this. This paper establishes the kinematics based on the structural characteristics of the SADWV and proposes a modified hybrid A*(MHA) algorithm that integrates SADWV's kinematics, building upon the hybrid A* algorithm(HA). Ultimately, the trajectory planning task for SADWV is introduced as an optimal control problem(OCP). The paper also employs the Safe Travel Corridor(STC) to avoid all obstacles during moving. The results from the MHA serve as the initial solution for the OCP and generate the guiding path for the STC. The design includes 20 simulation cases to test the proposed planner: the average solution time is 0.794 seconds, and the success rate of solving is 90%.