基于时空预测与转向优化的DWA动态路径规划

DWA-Based Dynamic Path Planning with Spatiotemporal Prediction and Steering Optimization

  • 摘要: 针对传统动态窗口法(DWA)在全局路径跟踪精度低、动态障碍物避障滞后及车辆运动学约束适配性不足等问题,提出一种多维度改进的DWA算法. 基于阿克曼转向模型构建转弯半径约束代价函数,通过指数型惩罚项抑制超限路径生成;设计时空轨迹预测机制,采用模型预测动态障碍物轨迹并计算碰撞风险,增强动态避障能力;提出分层动态权重调整策略,根据目标距离与障碍物邻近度实时优化权重分配;引入分数阶PID控制器优化轨迹跟踪,通过Grünwald-Letnikov离散化方法降低超调与稳态误差. 仿真和实车实验的结果表明,在无动态障碍物场景中,改进算法运动时间减少9.5%,路径长度缩短6.8%;动态障碍物场景下,路径长度进一步降低5.9%,迭代次数减少9.9%. 分数阶PID跟踪最大误差仅0.2 m,较传统PID控制的0.6 m显著优化. 结论表明,改进算法有效提升了路径规划的可行性、动态避障效率及轨迹跟踪精度,适用于复杂动态环境中的无人车局部路径规划.

     

    Abstract: To address the limitations of traditional dynamic window approach (DWA) in global path tracking accuracy, delayed dynamic obstacle avoidance, and inadequate adaptation to vehicle kinematic constraints, a multi-dimensional improved DWA algorithm was proposed. Methodologically, the study: 1) constructed a turning radius constraint cost function based on the Ackerman steering model, employing exponential penalty terms to suppress out-of-limit path generation; 2) designed a spatiotemporal trajectory prediction mechanism that utilized models to forecast dynamic obstacle trajectories and calculate collision risks, thereby enhancing dynamic obstacle avoidance capability; 3) proposed a hierarchical dynamic weight adjustment strategy that optimized weight allocation in real time based on target distance and obstacle proximity; 4) introduced a fractional-order PID controller for trajectory tracking optimization, employing Grünwald-Letnikov discretization to reduce overshoot and steady-state errors. Simulation and physical vehicle experiments demonstrate that in static obstacle scenarios, the improved algorithm reduced motion time by 9.5% and shortened path length by 6.8%; in dynamic obstacle environments, it achieved an additional 5.9% path length reduction with 9.9% fewer iterations. The fractional-order PID controller exhibited a maximum tracking error of merely 0.2 m, significantly outperforming the 0.6 m error of traditional PID control. The conclusion verifies that the improved algorithm effectively improves path planning feasibility, dynamic obstacle avoidance efficiency, and trajectory tracking precision, making it suitable for unmanned vehicle local path planning in complex dynamic environments.

     

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