The Task properties specify a list of Goals that the vehicle must fulfill.
Goals can be PathGoals or MetricGoals.
PathGoals specify one or multiple positions in the world that must be reached or avoided by the vehicle (depending on the LTL operator).
MetricGoals specify conditions on values, for example that the speed of the vehicle cannot be greater than 50km/h.
Task Properties
| Entry | Unit | Type | Description | Default Value |
|---|---|---|---|---|
goals |
[O] | A list of Goal properties. Goals can be of type path or metric. |
Goal Properties
Goal is an abstract class. Sub-types can be path or metric. All sub-types can have the following entry:
| Entry | Unit | Type | Description | Default Value |
|---|---|---|---|---|
ltl_operator |
S |
always, eventually or never. |
The LTL operator entry specifies when and how the goal must be fulfilled.
-
always: The goal must always be fulfilled. -
eventually: The goal must be fulfilled at one point in the simulation. -
never: The goal can never be fulfilled.
PathGoal Properties
PathGoals only support the eventually and never LTL operators.
In the eventually setting, the positions given by one of the path entries must be reached within range in the specified order.
In the never setting, none of the position can be reached at any point.
| Entry | Unit | Type | Description | Default Value |
|---|---|---|---|---|
type |
S | Must be path for a PathGoal. Must be the first entry. |
||
The following path, path_lonlat and path_osm entries are exclusive: they represent different ways of giving positions in the world. |
||||
path |
[m,m] | [Vec2] | A list of (local) world coordinates. | |
path_lonlat |
[lon,lat] | [Coordinates] | A list of Geographic coordinates. | |
path_osm |
[I] | A list of OSM node-ids (visible in the .osm files in the node tags). | ||
range |
m | I | The range (circular) around the given positions that counts as valid. | 2 m |
MetricGoal Properties
MetricGoals can specify conditions on PhysicalValues inside the vehicle. A list of those can be seen below the Sensor and Actuator Properties.
| Entry | Unit | Type | Description | Default Value |
|---|---|---|---|---|
type |
S | Must be metric for a MetricGoal. Must be the first entry. |
||
compare |
S | The name of the PhysicalValue to be compared. |
||
with |
FP | The value to be compared with. | 0.0 |
|
operator |
S | Comparison operator: <, <=, >, >= or ==. |
== |
The PhysicalValues list shows the useable values for the compare field.
Examples
This example requires the vehicle to reach the (10.1, -105.2) and (-63.83, -171.96) (local) coordinates within 5 meters, in this order.
It also requires the vehicle to always have its velocity smaller than 50.0 km/h (true_velocity is the physical value name).
"task": {
"goals": [
{
"type": "path",
"ltl_operator": "eventually",
"path": [ [10.1, -105.2], [-63.83, -171.96] ],
"range": 5
},
{
"type": "metric",
"ltl_operator": "always",
"compare": "true_velocity",
"with": "50.0",
"operator": "<"
}
]
}