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arXiv · 2509.06115

Hybrid A* Path Planning with Multi-Modal Motion Extension for Four-Wheel Steering Mobile Robots

Runjiao Bao·Lin Zhang·Tianwei Niu·Haoyu Yuan·Shoukun Wang
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Abstract

Four-wheel independent steering (4WIS) systems provide mobile robots with a rich set of motion modes, such as Ackermann steering, lateral steering, and parallel movement, offering superior maneuverability in constrained environments. However, existing path planning methods generally assume a single kinematic model and thus fail to fully exploit the multi-modal capabilities of 4WIS platforms. To address this limitation, we propose an extended Hybrid A* framework that operates in a four-dimensional state space incorporating both spatial states and motion modes. Within this framework, we design multi-modal Reeds-Shepp curves tailored to the distinct kinematic constraints of each motion mode, develop an enhanced heuristic function that accounts for mode-switching costs, and introduce a terminal connection strategy with intelligent mode selection to ensure smooth transitions between different steering patterns. The proposed planner enables seamless integration of multiple motion modalities within a single path, significantly improving flexibility and adaptability in complex environments. Results demonstrate significantly improved planning performance for 4WIS robots in complex environments.

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Runjiao Bao, Lin Zhang, Tianwei Niu, Haoyu Yuan, Shoukun Wang. 2025-09-07. Hybrid A* Path Planning with Multi-Modal Motion Extension for Four-Wheel Steering Mobile Robots. https://arxiv.org/abs/2509.06115

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