Scan Real Roads

The simulation.src.simulation_groundtruth.src.scan.node.ScanNode can read the car’s position from rosbags to create a simulated road.

The node listens to the ROS topic /tf and assumes that the car is always in the middle of the right lane. This requires a well suited rosbag.

Scanning new Roads

Adding new roads requires multiple (easy) steps:

  1. Start ROS:

    roscore

  2. Ensure that ROS uses time from the rosbag:

    rosparam set /use_sim_time true

  3. Start playing the rosbag with the rosbag’s clock:

    rosrun rosbag play ROSBAG_NAME --clock

    (You can always pause and play using the SPACE key.)

  4. Then start the scan node to generate a .yaml file with information about the part of the road played in the rosbag:

    roslaunch simulation_groundtruth scan_node.launch file_path:=PATH_TO_RESULTING_FILE

    When the node is stopped, a file containing the segment of the road the car drove while the node was running, is created.

  5. Add the scanned road section to an existing road:

    from simulation.utils.road.road import Road
from simulation.utils.road.sections import CustomSection

road = Road()
section = CustomSection.from_yaml(FILEPATH)
road.append(section)

    Currently, intersections can not be recorded like this. The best practice is to simply record the road before and after the intersection separately.

Example: Carolo-Cup 2020 Training Loop

A road that has been recreated from a rosbag is our training road at the Carolo-Cup in 2020. Some additional road sections and minor adjustments were required to fit all parts together.

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import math
import os

from simulation.utils.geometry import Point
from simulation.utils.road.road import Road  # Definition of the road class
from simulation.utils.road.sections import (
    CubicBezier,
    CustomSection,
    Intersection,
    RightCircularArc,
    StraightRoad,
)

road = Road()

custom_part_one: CustomSection = CustomSection.from_yaml(
    os.path.join(os.path.dirname(__file__), "./cc20_scans/training_part1.yaml")
)
road.append(custom_part_one)
road.append(StraightRoad(length=0.1))
road.append(RightCircularArc(radius=3, angle=math.radians(17)))
road.append(StraightRoad(length=0.08))
road.append(
    CubicBezier(
        p1=Point(0.1, 0),
        p2=Point(0.9, -0.05),
        p3=Point(1.0, -0.05),
        left_line_marking=StraightRoad.MISSING_LINE_MARKING,
        right_line_marking=StraightRoad.MISSING_LINE_MARKING,
        middle_line_marking=StraightRoad.MISSING_LINE_MARKING,
    )
)
road.append(
    CustomSection.from_yaml(
        os.path.join(os.path.dirname(__file__), "./cc20_scans/training_loop.yaml")
    )
)
road.append(StraightRoad(length=0.85))
road.append(
    Intersection(size=1.1, angle=math.radians(82), exit_direction=Intersection.STRAIGHT)
)
road.append(
    CustomSection.from_yaml(
        os.path.join(os.path.dirname(__file__), "./cc20_scans/training_part2.yaml")
    )
)
road.close_loop()