Only released in EOL distros:   kinetic

Dependencies

This package depends on the following message definitions:

• smach_msgs

• cpswarm_msgs

The communication between CPSs is based on the CPSwarm Communication Library.

The state that is exchanged is read from a SMACH state machine.

Execution

Run the launch file

roslaunch state_exchanger state_exchanger.launch

to launch the state_exchanger node.

The launch file can be configured with following parameters:

id (integer, default: 1)

• The identifier (ID) of the CPS used for name spacing in simulation.

output (string, default: screen)

• Whether to show the program output (screen) or to write it to a log file (log).

In the param subdirectory there is the parameter file state_exchanger.yaml that allows to configure the behavior of the state_exchanger node.

Nodes

state_exchanger

The state_exchanger node publishes behavioral states of this CPS to the rest of the swarm and publishes the state received from the other swarm members locally. The state is taken from a locally running SMACH state machine. If the CPS is in multiple states, only the first one is considered.

Subscribed Topics

smach_server/smach/container_status (smach_msgs/SmachContainerStatus)

• The current state of this CPS.

bridge/events/state (cpswarm_msgs/StateEvent)

• The current state of another CPS. Messages are exchanged between CPSs using the CPSwarm Communication Library.

Published Topics

state (cpswarm_msgs/StateEvent)

• The current state of this CPS that is forwarded by the CPSwarm Communication Library to the other swarm members.

swarm_state (cpswarm_msgs/ArrayOfStates)

• The states of the other swarm members received through the CPSwarm Communication Library.

Parameters

~loop_rate (real, default: 1.5)

• The frequency in Hz at which to run the control loops.

~queue_size (integer, default: 10)

• The size of the message queue used for publishing and subscribing to topics.

~timeout (real, default: 20.0)

• The time in seconds after which another CPS is considered to have left the swarm.

~sm_path (string, default: /SM_TOP)

• The path of the smach state machine whose state shall be exchanged.

Acknowledgements

This work is supported by the European Commission through the CPSwarm H2020 project under grant no. 731946.