9. Road Sections¶
The road you have created in the Road section sure looks nice but still is rather basic. In this section, you are going to create a more complex world by adding further road sections.
You can create and render the following road sections yourself by creating a custom road
from simulation.utils.road.road import Road from simulation.utils.road.sections import * road = Road() road.append(StraightRoad()) # Replace with other road sections
Then start the simulation:
roslaunch gazebo_simulation master.launch road:=example_road
simulation.utils.road.sections.straight_road.StraightRoad is a straight road.
This is an example on how to create a StraightRoad:
straight_road = StraightRoad(length=2)
simulation.utils.road.sections.parking_area.ParkingArea is a straight road
with parking lots on the left and right side.
right_lots each define a list of
Each parking lot can contain multiple
This is an example on how to create a ParkingArea:
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parking_area = ParkingArea( length=4, start_line=True, left_lots=[ ParkingLot( spots=[ ParkingSpot(kind=ParkingSpot.OCCUPIED, obstacle=ParkingObstacle()), ParkingSpot(kind=ParkingSpot.BLOCKED), ], ), ParkingLot( start=2, opening_angle=math.radians(40), spots=[ ParkingSpot(), ParkingSpot(kind=ParkingSpot.OCCUPIED, obstacle=ParkingObstacle()), ], ), ], right_lots=[ ParkingLot( start=1, depth=0.4, spots=[ ParkingSpot(kind=ParkingSpot.FREE, width=0.5), ParkingSpot( kind=ParkingSpot.OCCUPIED, width=0.7, obstacle=ParkingObstacle() ), ParkingSpot(kind=ParkingSpot.BLOCKED), ], ) ], )
The ParkingArea takes three optional arguments, which are
In the example,
start_line is set to
StartLine(). This creates a StartLine at the beginning of the ParkingArea.
If you do not want a StartLine, remove
start_line=StartLine(). By default,
You can also discover this if you take a closer look at
If you want to take this one step further, it is also possible to create a ParkingArea without any children; practically a StraightRoad.
right_lots expect a list of ParkingLots. In this example two lots are created on the left and one is on the right side.
In the first lot on the left side, two ParkingSpots are placed. As you already know, ParkingSpots can have three different types.
The first spot in this example is occupied by a ParkingObstacle, the second is blocked, i.e. it looks like an X.
The second lot on the left looks different. You can also specify a
length and an
opening_angle for a ParkingLot.
Here, the start is set to two meters from the beginning of the ParkingArea. If you do not specify the start argument (like in the first lot) it is set to zero.
The opening angle is set to 40 degrees; the default is 60 degrees.
For the first spot in this lot, no arguments are given and thus it’s kind is ParkingSpot.FREE and there’s no obstacle placed inside.
This is the default behavior for a ParkingSpot.
Be careful: it is possible to place an obstacle on a free spot. The rendered road will look perfectly fine but it can cause problems in automatic driving tests because on a free spot no obstacle is expected.
Moving to the single lot on the right side, you can see the third optional argument for a ParkingLot.
It is called
depth and controls the depth (along the y-axis) of a lot.
There is no length parameter because the length (along the x-axis) is calculated as the sum of all spots in one lot.
To change the size of a spot along the x-axis, simply specify a
You can not set the depth of a spot because it is derived from the parent lot.
intersection = Intersection(size=2, turn=Intersection.RIGHT, angle=math.radians(110))
In this example, the crossing roads intersect at a 110-degree angle.
turn parameter indicates in which direction the road continues
after the intersection.
The possible turn values are
the latter is the default.
The default size is 1.8 m and represents the length of each of the crossing roads.
The zebra crossing spans the entire length of this section. If no length argument is given, it defaults to 0.45 m.
zebra_crossing = ZebraCrossing(length=0.5)
This section creates a circular arc pointing to the left (LeftCircularArc) and right (RightCircularArc).
This means instead of creating an arc with a negative radius to make it turn right the radius is always positive.
The two required parametes for an arc are
left_arc = LeftCircularArc(radius=2, angle=math.radians(90))
This example creates a circular arc to the left resulting in a 90-degree turn.
simulation.utils.road.sections.blocked_area.BlockedArea is a straight road,
but the car is not allowed to drive on the blocked area which is marked by parallel white lines.
By default the section is 1 m in length and the blocked area is 0.2 m wide, starting on the right line.
This is an example on how to create a BlockedArea with a length of 1 m and a blocked area which is 0.2 m in width:
blocked_area = BlockedArea(length=1, width=0.2)
simulation.utils.road.sections.traffic_island.TrafficIsland consists of
a visible traffic island in the center of the road and a crosswalk or just dashed lines
connecting the island with both sides of the road. B
Pedestrians are coming soon!
The parameters in the following example are also the default parameters:
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traffic_island = TrafficIsland( island_width=0.3, zebra_length=0.45, curve_area_length=0.8, curvature=0.4, zebra_marking_type=TrafficIsland.ZEBRA, )
9.8. Create Road¶
While the above introduction to the different road section is not complete and does neither explain all possible parameters which can be set nor introduces all road sections available, it is sufficient for completing the following task. If you want more information on the road sections just have all look at simulation.utils.road.sections the source code.
Create a new road with the following sections:
straight road: length 1 m
parking area: length 3.5 m
left lot: start after 0.5 m, depth 0.5 m, three parking spots
right lot: start after 1.5 m, two spots with a width of 70 cm
circular arc to the left: radius 2 m, angle 90 degrees
intersection: turn to the left, size 3 m
circular arc to the right: radius 1.5 m, angle 90 degrees
circular arc to the left: radius 2.5 m, angle 60 degrees
straight road: length 80 cm
circular arc to the left: radius 2.5 m, angle 120 degrees
intersection: size 3.2 m, angle 110 degrees, go straight
straight road: length 1.66 m
circular arc to the left: radius 1 m, angle 90 degrees
straight road: length 1.25 m
The road should form a closed loop.
Do not forget to import necessary sections.
You can look at the road you have defined by starting the simulation!
All angles must be specified in radians!
Don’t forget to commit and push your changes after completing the task!
By default, new roads are not included into git because we don’t want to have everybody’s roads in our repository!
However, if you want to commit a road (like you should do here!). you can go into the roads folder (
simulation/models/env_db) and execute:
git add -f <FILE_NAME>