Complete‐coverage trenching trajectory planning for excavators via reachability and excavation force maps

Current trenching trajectory planning methods for autonomous excavators primarily focus on a single cycle, lacking overall optimization of the entire task. This study proposes an offline method for overall optimization of trenching trajectories via reachability and excavation force maps. This method can generate a complete set of trajectories that covers the entire target trench area and satisfies the excavation force requirements without relying on expert demonstration data, which is conducive to improving the overall trenching efficiency. First, a base-position selection method that considers both force and pose requirements is proposed. Second, rules for generating key points of trenching trajectories are established. Subsequently, an overall optimization method for all trajectories covering the entire trench area is proposed. Finally, a prototype and an experimental scenario were built, and trenching experiments on four trench shapes are conducted. The results demonstrate that the planning process is completed within a few minutes, and the trench profiles obtained from the trenching experiments closely match the target shapes.