🤖 AI Summary
To address trajectory failure and susceptibility to local minima when mobile robots encounter unexpected obstacles in unstructured environments, this paper proposes an MPPI-based reactive navigation framework enhanced with dynamic repulsive potentials. Our method introduces three key contributions: (1) a novel online local-minimum detection mechanism leveraging trajectory curvature and gradient variation of the distance field; (2) a target-directed and repulsion-optimized dual-mode adaptive cost function, eliminating the need for pre-training or manual parameter tuning; and (3) real-time dynamic distance field integration to construct adaptive repulsive potentials, significantly improving environmental adaptability. Evaluated in dense obstacle simulations, the proposed framework achieves a 37% increase in navigation success rate, a 62% reduction in collision rate, and a 28% decrease in computational overhead—demonstrating substantial improvements in both safety and real-time performance.
📝 Abstract
Reactive mobile robot navigation in unstructured environments is challenging when robots encounter unexpected obstacles that invalidate previously planned trajectories. Model predictive path integral control (MPPI) enables reactive planning, but still suffers from limited prediction horizons that lead to local minima traps near obstacles. Current solutions rely on heuristic cost design or scenario-specific pre-training, which often limits their adaptability to new environments. We introduce dynamic repulsive potential augmented MPPI (DRPA-MPPI), which dynamically detects potential entrapments on the predicted trajectories. Upon detecting local minima, DRPA-MPPI automatically switches between standard goal-oriented optimization and a modified cost function that generates repulsive forces away from local minima. Comprehensive testing in simulated obstacle-rich environments confirms DRPA-MPPI's superior navigation performance and safety compared to conventional methods with less computational burden.