8.10 Environment actors :: OpenSCENARIO

8.10.1 Environment

In ASAM OpenSCENARIO, all settings or changes to the environment are conducted through the environment actor. For a detailed definition of the actions that can be executed by the environment actor, see Section 8.11.1, "Actions for environment".

8.10.2 Actor environment

The environment actor executes all environment actions.

Note that the environment model is partitioned in a way that facilitates custom extensions and extensions for future versions of ASAM OpenSCENARIO. Therefore, some classes may carry only one member variable for the time being. For example, instead of adding 'fog_visual_range' as a direct property of the 'environment' actor, the class 'fog' contains visual_range as a property. In that way, an extension like adding properties like 'bounding_box' and 'position' to the class 'fog' is easier and readibility is improved at the same time.

Note that when defining 'geodetic_position' and 'datetime', the position of instances of 'celestial_light_source' (like 'sun' or 'moon') shall be calculated with underlying models resulting also in a change of their position with elapsing simulation time. For fixed positions of instances of 'celestial_light_source', their 'celestial_position' shall be set using the assign_celestial_postion action instead. Setting this state shall override calculated positions in case 'geodetic_position' and 'datetime' are specified as well.

Basic information

Table 123. Basic information of actor environment
Instantiable	yes
Parents	osc_actor

Parameters

Table 124. Actor environment
Parameter	Type	Mandatory	Description
geodetic_position	geodetic_position_2d	no	Geodetic position of world coordinate frame regarding WGS84. Regarding usage for determination of angle of celestial light sources see remark above.
datetime	time	no	Date and time at start of scenario as Unix time, i.e. Number of seconds that have elapsed since January 1, 1970 (midnight UTC/GMT), not counting leap seconds. Regarding usage for determination of angle of celestial light sources see remark above.
sun	celestial_light_source	no	Sun as instance of celestial_light_source.
moon	celestial_light_source	no	Moon as instance of celestial_light_source.

State variables

Table 125. State variables of actor environment
Variable	Type	Mandatory	Description
weather	weather	no	See weather

8.10.2.1 Methods

8.10.2.1.1 Method local_to_unix_time()

Returns the unix time from local date and time input.

Prototype

extend environment:
    def local_to_unix_time(year: uint, month: uint, day: uint, hour: uint, minute: uint, second: uint, time_zone: float) -> time

Return value

Returns the unix time to be used for environment actor with the local date, time and the time zone as input.

Parameters

Table 126. Parameter for method local_to_unix_time()
Parameter	Type	Description
year	uint	Year with century, e.g. 2022.
month	uint	Month in the range of 1 to 12.
day	uint	Day of the month in the range of 1 to 31.
hour	uint	Hour (24-hour clock) in the range of 0 to 23.
minute	uint	Minute in the range of 0 to 59.
second	uint	Seconds in the range of 0 to 60, 60 for representing leap seconds.
time_zone	float	Time zone offset indicating a positive or negative time difference from UTC/GMT in hours. Using type float because e.g. Îles Marquises use -9.5.

8.10.2.2 Examples

Code 64. Syntax examples for environment actor

# instantiate the environment actor
environment: environment

# set datetime with unix time
keep(environment.datetime == 1643764822.0)
# alternative: use local_to_unix_time for convenience and better readability
keep(environment.datetime == environment.local_to_unix_time(year: 2022, month: 2, day: 2, hour: 2, minute: 20, second: 22, time_zone: 0))
# note: this can be shortened by dropping the names of the arguments while preserving their order
keep(environment.datetime == environment.local_to_unix_time(2022, 2, 2, 2, 20, 22, 0))

# set geodetic position
keep(environment.geodetic_position.lat == 48.0231718deg)
keep(environment.geodetic_position.lon == 11.68087deg)

8.10.3 Struct weather

Structure for weather related effects.

Basic information

Table 127. Basic information of struct weather
Instantiable	yes
Used by	environment

Parameters

Table 128. Struct weather
Parameter	Type	Mandatory	Description
air	air	no	See air
rain	precipitation	no	Liquid water in form of droplets falling under gravity.
snow	precipitation	no	Frozen water in delicately-crystalline flakes falling under gravity.
wind	wind	no	See wind
fog	fog	no	See fog
clouds	clouds	no	See clouds

8.10.4 Struct air

Structure for air related effects.

Basic information

Table 129. Basic information of struct air
Instantiable	yes
Used by	weather

Parameters

Table 130. Struct air
Parameter	Type	Mandatory	Description
temperature	temperature	no	Temperature on ground level.
pressure	pressure	no	Atmospheric pressure on ground level.
relative_humidity	float	no	Relative humidity on ground level.

8.10.5 Struct precipitation

Structure for air related effects for different types of precipitation.

Basic information

Table 131. Basic information of struct precipitation
Instantiable	yes
Used by	weather

Parameters

Table 132. Struct precipitation
Parameter	Type	Mandatory	Description
intensity	speed	no	Global intensity of precipitation given as volumetric flux. In case of (partially) solid precipitation, the equivalent melted volume shall be considered. Note that volumetric flux is describing a volume flow across an area in units of mmph or millimeter_per_hour. After reduction, the unit results in the same unit as for speed. As of now, it is not possible to define multiple physical types with the same unit. Therefore, the speed type is used for volumetrix flux as well.

8.10.6 Struct wind

Properties relating to wind.

Basic information

Table 133. Basic information of struct wind
Instantiable	yes
Used by	weather

Parameters

Table 134. Struct wind
Parameter	Type	Mandatory	Description
speed	speed	yes	The expected value of wind speed. To estimate the expected value, rolling mean value over a specific short interval (for example, 3s) can be used.
direction	angle	yes	The origin direction of the wind (not target direction) in the ground/x-y-plane with clockwise increasing values to match common definitions. This results in 0 deg for a wind blowing from the North 90 deg for a wind blowing from the East 90 deg, if x-axis and y-axis are mapped to East and North.

8.10.7 Struct fog

Visible aerosol consisting of water droplets suspended in the air close to ground level.

Basic information

Table 135. Basic information of struct fog
Instantiable	yes
Used by	weather

Parameters

Table 136. Struct fog
Parameter	Type	Mandatory	Description
visual_range	length	yes	Value of optical range of visible light in the standard setting, which corresponds to a certain density of fog.

8.10.8 Struct clouds

Specification of the clouds in the sky.

Basic information

Table 137. Basic information of struct clouds
Instantiable	yes
Used by	weather

Parameters

Table 138. Struct clouds
Parameter	Type	Mandatory	Description
cloudiness	uint	yes	Using okta scale to define which portion of the sky is covered with clouds. Ranging from 0 for completely clear sky to 8 for a completely overcast sky. Values above 8 shall not be used.

8.10.9 Struct celestial_light_source

Celestial light sources, typically sun or moon.

Basic information

Table 139. Basic information of struct celestial_light_source
Instantiable	yes

State variables

Table 140. State variables of struct celestial_light_source
Variable	Type	Mandatory	Description
position	celestial_position_2d	yes	Position of the light source, see definition of physical type celestial_position_2d.