A Hierarchical Hybrid Search Framework for Fixed-Length Cable Routing

Traditional cable path planning prioritizes shortest-path optimization, creating a mismatch with high-end equipment that requires pre-manufactured fixed-length cables. To address this challenge, this paper proposes a hierarchical hybrid search framework for fixed-length cable path planning. First, a mathematical model incorporating non-interference, minimum bending radius, and strict length equality constraints is established alongside an engineering evaluation system. The framework then executes a three-stage strategy: the Direct Improved Hybrid A* algorithm first explores the global workspace; if it fails to converge, the Multi-Stage Guided Improved Hybrid A* algorithm activates using topological guidance and segmented step allocation for complex environments; finally, a Dubins curve-based module compensates for discrete search residuals and handles rigid connector splicing conditions. Benchmarked against standard Hybrid A* and Dubins-RRT*, the proposed framework achieves a 100% success rate across all test scenarios while reducing the maximum length errors to within 0.2 mm. This approach effectively resolves the forward design challenges of fixed-length cable routing in planar, surface-conforming scenarios.