swarm_behaviors_flocking

This package provides functionalities for flocking and formation flight. It is a library package of the swarm behaviors library.

Dependencies

This package depends on the following message definitions: * geometry_msgs * cpswarm_msgs

The following library packages of the swarm behaviors library are required: * position * velocity

The following packages of the swarm functions library are required: * kinematics_exchanger

The following packages of the sensing and actuation library are required: * area_provider

Further required packages are: * roscpp

Libraries

flocking

The flocking library provides functionalities for flocking and formation flight. It calculates the required velocity for a CPS to either stay in a flock or to create a specific formation with a swarm of CPSs.

Subscribed Topics

• swarm_position_rel (cpswarm_msgs/ArrayOfVectors) Relative positions of the other swarm members
• swarm_position (cpswarm_msgs/ArrayOfPositions) Absolute positions of the other swarm members.
• swarm_velocity_rel (cpswarm_msgs/ArrayOfVectors) Relative velocities of the other swarm members.

Services Called

• area/get_center (cpswarm_msgs/GetPoint) Get the center of the area.

Parameters

• ~loop_rate (real, default: 5.0) The frequency in Hz at which to run the control loops.
• ~queue_size (integer, default: 1) The size of the message queue used for publishing and subscribing to topics.
• ~start_delay (real, default: 1.0) The Time in seconds to wait during startup for other CPSs.
• ~equi_dist (real, default: 10.0) Equilibrium distance between CPSs in meter.
• ~repulse_spring (real, default: 1.0) Repulsion spring constant of half-spring per square second.
• ~repulse_max (real, default: 1.0) Maximum repulsion between CPSs in meter in order to avoid over excitation.
• ~align_frict (real, default: 20.0) Velocity alignment viscous friction coefficient in square meter per second. Higher values result in slower but more stable flocks.
• ~align_slope (real, default: 1.0) Constant slope around equilibrium distance in meter.
• ~align_min (real, default: 1.0) Minimum alignment between CPS in meter in order to avoid over excitation.
• ~wall_frict (real, default: 20.0) Bounding area viscous friction coefficient in square meter per second.
• ~wall_decay (real, default: 1.0) Softness of wall as decay width in meter.
• ~accel_time (real, default: 1.0) Characteristic time needed by the CPS to reach the target velocity in seconds.
• ~flocking/flock_vel (real, default: 0.5) Target velocity of the flock in meter per second.
• ~formation/formation (string) The type of formation to create. Can be grid, ring, or line.
• ~formation/form_vel (real, default: 0.5) Maximum velocity during formation flight in meter per second.
• ~formation/form_shape (real, default: 1.0) Strength of the shape forming velocity component in formation flight.
• ~formation/form_track (real, default: 1.0) Strength of the tracking velocity component in formation flight.
• ~formation/form_decay (real, default: 1.0) Softness of shape in meter.

Code API

swarm_behaviors_flocking package code API documentation