Isaac ROS JSON Info Generator

Overview

The isaac_ros_json_info_generator package has the JsonInfoGeneratorNode that collects data/messages from an arbitrary number of topics (of any defined ROS message type). It converts the collected messages into a JSON string, stores that string in a std_msgs/String, and publishes that ROS 2 string to /info, where the mission client (i.e. isaac_ros_vda5050_nav2_client) will collect and then relay that information to the mission dispatcher. The node also subscribes to the topic /order_id (std_msgs/String) and stores that as the current order_id; if the new order_id value is different from the one stored, it will clear the messages it collected and start collecting messages again.

Launch Scripts

isaac_ros_json_info_generator Launch Script

This launch script under the launch directory brings up the JsonInfoGenerator node. This launch script uses a parameter YAML file under the config folder in json_info_generator_params.yaml. These are the following parameters that users can configure: | Parameter | Description | Default Value | | ————————- | ——————————————————————————————————————————————————————————————————- | —————- | | ros_subscriber_types | The message types for each topic the user wants the node to subscribe to | [] (empty array) | | ros_subscriber_topics | The topic names for each topic the user wants the node to subscribe to. Note: Each element in this parameter’s array corresponds to the element of the same index in ros_subscriber_types | [] (empty array) | | ros_pub_sub_queue | The queue value used for the publishers and subscribers generated in this node. | 10 | | messages_aggregated_count | if messages_aggregated is set to True, this value sets the number of messages to store for each topic before removing the old messages. The messages will be removed in a first-in-first-out order. | 10 | | update_period | How often the node should publish the messages collected (in seconds) | 1 |

Usage

After building this package, you can executable this node by running:

ros2 launch isaac_ros_json_info_generator isaac_ros_json_info_generator.launch.py

You can modify the parameter values by changing the values in config/json_info_generator_params.yaml.