Agent

class Agent

This class describes an agent.

The agent navigates in the environment using a task, a state estimation, 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 task and state estimation is to provide goals and environment state (perception) to the behavior.

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_estimation: object = None, 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

• estimation – The estimation

• 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

dump() → str

Dumps the object to a YAML-string.

Returns:

The YAML representation

Return type:

str

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

Gets the last command.

Returns:

The controller.

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 modulation from a 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]

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 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 state estimation.

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