Energy-Constrained Navigation for Planetary Rovers under Hybrid RTG-Solar Power

Future planetary exploration rovers must operate for extended durations on hybrid power inputs that combine steady radioisotope thermoelectric generator (RTG) output with variable solar photovoltaic (PV) availability. While energy-aware planning has been studied for aerial and underwater robots under battery limits, few works for ground rovers explicitly model power flow or enforce instantaneous power constraints. Classical terrain-aware planners emphasize slope or traversability, and trajectory optimization methods typically focus on geometric smoothness and dynamic feasibility, neglecting energy feasibility. We present an energy-constrained trajectory planning framework that explicitly integrates physics-based models of translational, rotational, and resistive power with baseline subsystem loads, under hybrid RTG-solar input. By incorporating both cumulative energy budgets and instantaneous power constraints into SE(2)-based polynomial trajectory optimization, the method ensures trajectories that are simultaneously smooth, dynamically feasible, and power-compliant. Simulation results on lunar-like terrain show that our planner generates trajectories with peak power within 0.55 percent of the prescribed limit, while existing methods exceed limits by over 17 percent. This demonstrates a principled and practical approach to energy-aware autonomy for long-duration planetary missions.

Handle Object Navigation as Weighted Traveling Repairman Problem

Zero-Shot Object Navigation (ZSON) requires agents to navigate to objects specified via open-ended natural language without predefined categories or prior environmental knowledge. While recent methods leverage foundation models or multi-modal maps, they often rely on 2D representations and greedy strategies or require additional training or modules with high computation load, limiting performance in complex environments and real applications. We propose WTRP-Searcher, a novel framework that formulates ZSON as a Weighted Traveling Repairman Problem (WTRP), minimizing the weighted waiting time of viewpoints. Using a Vision-Language Model (VLM), we score viewpoints based on object-description similarity, projected onto a 2D map with depth information. An open-vocabulary detector identifies targets, dynamically updating goals, while a 3D embedding feature map enhances spatial awareness and environmental recall. WTRP-Searcher outperforms existing methods, offering efficient global planning and improved performance in complex ZSON tasks. Code and more demos will be avaliable on https://github.com/lrm20011/WTRP_Searcher.