Motion Planning With Carla Simulator

[TOC]

1.依赖

• Ubuntu18.04
• ROS Melodic
• carla-simulator 0.9.9.4
• carla-ros-bridge

2. Ros Graph

3. 参考线

3.1 样条曲线

样条曲线： 用于生成参考线。

3.2 参考线平滑

Object Function: $$ J = w_{1} \sum_{i = 1}^{N-1} ((x[i] - x[i - 1]) ^2 + (y[i] - y[i-1])^2) + \ w_2 \sum_{i=0}^{N-1} ((x[i] - x_{\text{ref}}[i])^2 + (y[i] - y_{\text{ref}}[i])^2) + \w_3 \sum_{i = 1}^{N-2}((x[i+1] + x[i-1]-2x[i])^2 + (y[i+1]+y[i-1]-2y[i])^2) $$ Constraints: $$ x_{\text{ref}}[i] - b[i] \leq x[i] \leq x_{\text{ref}}[i] + b[i], i = 0,\ldots, N-1. \ y_{\text{ref}}[i] - b[i] \leq y[i] \leq y_{\text{ref}}[i] + b[i], i = 0,\ldots, N-1. \ ((x[i+1] + x[i-1]-2x[i])^2 + (y[i+1]+y[i-1]-2y[i])^2) \leq (k_{\max} \Delta s^2)^2 $$

其中，$b[i] , i = 0, \ldots,N-1$ 为waypoint 的上下界。$x_{\text{ref}}[i], y_{\text{ref}}[i]$ 为原始waypoint的坐标值。约束项第三项为曲率约束。

求解器： IPOPT

3.3 样条曲线上最近点

Robust and Efficient Computation of Closest Point on a Spline. Quaradic Minimization + Newton's Method

4. 碰撞检查

5. 规划器

5.1 Frenet Lattice Planner

done

5.2 PVD Planner

todo

6. 控制器

6.1 Pid_PurePursuit

纵向控制： PID

横向控制： Pure Pursuit

6.2 Pid_Stanley

纵向控制： PID

横向控制： Stanley

6.3 MPC

todo

7. Result