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arXiv · 2504.12719

B*: Efficient and Optimal Base Placement for Fixed-Base Manipulators

Zihang Zhao·Leiyao Cui·Sirui Xie·Saiyao Zhang·Zhi Han·Lecheng Ruan·Yixin Zhu
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Abstract

B* is a novel optimization framework that addresses a critical challenge in fixed-base manipulator robotics: optimal base placement. Current methods rely on pre-computed kinematics databases generated through sampling to search for solutions. However, they face an inherent trade-off between solution optimality and computational efficiency when determining sampling resolution. To address these limitations, B* unifies multiple objectives without database dependence. The framework employs a two-layer hierarchical approach. The outer layer systematically manages terminal constraints through progressive tightening, particularly for base mobility, enabling feasible initialization and broad solution exploration. The inner layer addresses non-convexities in each outer-layer subproblem through sequential local linearization, converting the original problem into tractable sequential linear programming (SLP). Testing across multiple robot platforms demonstrates B*'s effectiveness. The framework achieves solution optimality five orders of magnitude better than sampling-based approaches while maintaining perfect success rates and reduced computational overhead. Operating directly in configuration space, B* enables simultaneous path planning with customizable optimization criteria. B* serves as a crucial initialization tool that bridges the gap between theoretical motion planning and practical deployment, where feasible trajectory existence is fundamental.

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Zihang Zhao, Leiyao Cui, Sirui Xie, Saiyao Zhang, Zhi Han, Lecheng Ruan, Yixin Zhu. 2025-04-17. B*: Efficient and Optimal Base Placement for Fixed-Base Manipulators. https://doi.org/10.1109/lra.2025.3604741

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