Catalog of Behaviors

This catalog shows the available behaviors provided by Aerostack. They are presented according to the following categories: motion behaviors, behaviors for environment understanding, and behaviors for communication.

It is important to note that there are two types of behaviors:

• Goal-based behaviors. These behaviors are defined to reach a final state (attain a goal). For example, the behavior TAKE_OFF ends when the drone has reached a certain height.

• Recurrent behaviors. These behaviors perform an activity recurrently or maintain a desired state (for example, the behavior PAY_ATTENTION_TO_VISUAL_MARKERS).

You can consult the following link to know how to add your own behaviors:

• Program new behaviors

Motion behaviors

Behavior TAKE_OFF

The robot takes off vertically from a static surface to the normal altitude. Type: goal-based behavior.

Behavior LAND

The robot lands vertically in the current position. This behavior assumes that the floor is static. Type: goal-based behavior.

Behavior KEEP_HOVERING

The robot keeps hovering. Hovering is a maneuver in which the robot is maintained in nearly motionless flight over a reference point at a constant altitude and on a constant heading. This behavior does not avoid moving obstacles. Type: recurrent behavior.

Behavior KEEP_MOVING

The robot keeps moving at a constant speed in some direction (forward, backward, left,right). If the speed value is not given a default value is considered. This behavior does not avoid obstacles. Type: recurrent behavior.

Arguments	Format	Example
direction	{FORWARD, BACKWARD, LEFT, RIGHT}	direction: FORWARD
speed	number (m/sec)	speed: 12

Behavior ROTATE

The robot rotates some degrees in a certain axis (yaw). Type: goal-based behavior.

Arguments	Format	Example
angle	number (degrees)	angle: 90
relative_angle	number (degrees)	relative_angle: 90

Behavior WAIT

The robot keeps doing the action while waiting for timeout or seeing a certain visual marker or both. Type: goal-based behavior.

Arguments	Format	Example
timeout	number(seconds)	timeout: 30
until_observed_visual_marker	number (visual marker id)	until_observed_visual_marker: 1

Behavior FOLLOW_OBJECT_IMAGE

The robot follows the image of a moving object, keeping a certain constant distance between the robot and the object. The operator selects the image to follow through the user interface. Type: recurrent behavior.

To select the object image to follow using the OpenTLD GUI you have to press the F5 button to refresh the image on the screen, select the area you want the drone to follow and then press and hold (just for few seconds) the ENTER key. Then the drone will start following the selected area.

Behavior GO_TO_POINT

The robot goes to a given point avoiding obstacles. The robot generates automatically a trajectory that avoids obstacles. The trajectory follows horizontal movements in two dimensions (2D). The point can be expressed using absolute coordinates (argument “coordinates”) or coordinates relative to the vehicle (argument “relative coordinates”). Type: goal-based behavior.

Arguments	Format	Example
coordinates	Tuple of 3 numbers x, y, z (meters)	coordinates: [1.23, 2, 0.5]
relative_coordinates	Tuple of 3 numbers x, y, z (meters)	relative_coordinates: [1.23, 2, 0.5]

Behaviors for environment understanding

Behavior PAY_ATTENTION_TO_VISUAL_MARKERS

The robot pays attention to visual markers (ArUco markers). The recognized markers are stored as beliefs.Type: recurrent behavior.

Behavior SELF_LOCALIZE_BY_ODOMETRY

The robot self localizes using odometry. To obtain good trajectories with visual odometry it is necessary to fly in a controlled environment (e.g., good illumination without reflections and a non visually uniform ground). Type: recurrent behavior.

Behavior SELF_LOCALIZE_BY_VISUAL_MARKERS

The robot self localizes using visual markers (ArUco markers). Type: recurrent behavior.

Behaviors for communication

Behavior REQUEST_OPERATOR_ASSISTANCE

This behavior presents (e.g., through a pop-up window) a text message and a list of options to select. The operator selects one of the options and the selection is written in the belief memory. Type: goal-based behavior.

Arguments	Format	Example
MESSAGE	text	MESSAGE: "The light intensity is very low"
OPTIONS	list of texts	OPTIONS: ["Turn on light","Land"]