Enhanced Bézier curve-based trajectory planning for high-altitude autonomous trucks

Highway freight transport is the backbone of Tibet's logistics network, accounting for 76.4% of regional freight movement (Tibet Bureau of Statistics, 2024). Challenging alpine road conditions-characterized by steep grades, sharp curves, and narrow lanes-combine with the substantial dimensions of heavy trucks to create significant operational difficulties. Autonomous truck development offers a potential solution; however, their trajectory planning algorithms exhibit limitations in high-altitude environments. To address these challenges, we propose a novel trajectory planning method using quartic Bézier curves. These 4th-order parametric curves provide G² continuity. Our approach integrates speed profiles into a three-dimensional curve representation and employs a two-phase optimization process to ensure safety and efficiency. Simulation results demonstrate the method's effectiveness in maintaining truck stability while enabling responsive maneuvering under Tibet's demanding road conditions.