Agent

class Agent

This class describes an agent.

The agent navigates in the environment using a task, a vector (or list in Python) of state estimations, a kinematic and a behavior, and a controller.

Agents have a circular shape which should match the shape of their navigation Behavior.

The role of the task is to provide goals to the behavior, while the role of state estimations is to update the environment state (perception) of the behavior.

State estimations are evaluated in constant order, each operating on the behavior environment state. For example, if an agent has two state estimations SE1 and SE2, when World.update() is called, the agent updates the behavior environment state S as SE1(S); SE2(S);

Agents have a public identifies id that is accessible by the other agents’ state estimation and may be passed to their behavior as Neighbor.id. This identifier may not be unique (e.g., may be used to identifies groups of agents).

Agents runs their update at the rate set by control_period even if the world is updated at a faster rate.

__init__(radius: float = 0, behavior: object = None, kinematics: object = None, task: object = None, state_estimations: list[object] = [], control_period: float = 0, id: int = 0) → None

Constructs a new instance.

Parameters:

• radius – The radius of the agent

• behavior – The behavior

• kinematics – The kinematics

• task – The task

• estimations – The state estimations

• control_period – The control period

• id – The public identifier

actuate(cmd: navground.core.Twist2, time_step: float) → None

Actuate the current agent control command.

Parameters:

dt – The time step

add_tag(tag: str) → None

Adds a tag.

Parameters:

tag – The tag

clear() → None

Remove all attributes

dump() → str

Dumps the object to a YAML-string.

Returns:

The YAML representation

Return type:

str

get(name: str) → bool | int | float | str | Vector2 | list[bool] | list[int] | list[float] | list[str] | list[Vector2] | None

Gets the value of the specified attribute.

Parameters:

name – The name of the attribute

Returns:

The value of the attribute

get_last_cmd(frame: navground.core.Frame) → navground.core.Twist2

Gets the last command.

Returns:

The controller.

has(name: str) → bool | int | float | str | Vector2 | list[bool] | list[int] | list[float] | list[str] | list[Vector2] | None

Checks if the specified attribute is set.

Parameters:

name – The name of the attribute

Returns:

True if the attribute is present.

has_been_in_collision_since(time: float) → bool

Determines if the entity has been in collision at least once since the given time.

Parameters:

time – The time

Returns:

True if been in collision since, False otherwise.

has_been_stuck_since(time: float) → bool

Determines if the agent has been stuck since a given time.

Parameters:

time – The time

Returns:

True if been stuck since, False otherwise.

static load(value: str) → object

Load a agent from a YAML string.

Parameters:

value – the YAML string.

Returns:

The loaded agent or None if loading fails.

Return type:

Agent| None

remove_tag(tag: str) → None

Removes a tag.

Parameters:

tag – The tag

static schema() → object

Returns the json-schema

Returns:

json-schema

Return type:

dict[str, typing.Any]

set(name: str, value: bool | int | float | str | Vector2 | list[bool] | list[int] | list[float] | list[str] | list[Vector2]) → None

Set the value of a named attribute.

Parameters:

• name – The name of the property

• value – The desired value for the attribute

property actuated_cmd

Type:

navground.core.Twist2

The last actuated command.

the actuated command is always kinematically feasible

property angular_speed

Type:

float

Angular speed

property attributes

Type:

dict[str, Union[bool, int, float, str, Vector2, list[bool], list[int], list[float], list[str], list[Vector2]]]

All attributes.

property behavior

Type:

navground.core.Behavior

The navigation behavior.

property color

Type:

str

The color of the agent.

A valid CSS color to fill the agent in the UI or empty to use the default color.

property control_period

Type:

float

The control period

property controller

Type:

navground.core.Controller

The navigation controller.

property enabled

Type:

bool

Whether the agent is enabled.

disabled agents are ignored in the simulation.

property id

Type:

int

The agent public identifier

property idle

Type:

bool

Returns whether the task is done and the control is idle.

Returns:

False if it has an active task or if the control is running

property kinematics

Type:

navground.core.Kinematics

The kinematics.

property last_cmd

Type:

navground.core.Twist2

The last command.

property last_collision_time

Type:

float

Returns the last collision time

property orientation

Type:

float

Orientation

property pose

Type:

navground.core.Pose2

The current pose.

property position

Type:

Vector2

Position

property radius

Type:

float

The agent radius

property state_estimation

Type:

navground.sim.StateEstimation

The first state estimation.

property state_estimations

Type:

list[navground.sim.StateEstimation]

The state estimations.

property tags

Type:

set[str]

A set of tags used to label the agent.

Tags are used to add meta-information about an agent, for instance when it gets generated by a scenario.

property task

Type:

navground.sim.Task

The task.

property time_since_stuck

Type:

float

The time since the agents has been stuck.

property twist

Type:

navground.core.Twist2

The current twist.

property type

Type:

str

The type of the agent.

The agent type should not used by the neighbors state estimation. It is mainly used internally to draw the agents in the UI.

property velocity

Type:

Vector2

Velocity

Note

Class Agent supports dynamic attributes <attributes python>.