Schedule activities in Simulation Framework

An Activity is basic simulation participant in simulation framework, where Topics can be provided or consumed between other activities. To fulfill the simulation demands, all activities can be scheduled through user scheduling config.

Scheduling Concept

It provides the feature that the user can define what Activities and how they should behave in simulation. With the configuration file in json format, user could define which activities, their topics' cycle times, their location and type. It is parsed and understood by scheduler core and during the simulation, scheduler sends corresponding events to different target activity via communication middleware. Thus, the activities can be scheduled under a deterministic behavior.

How should write simulation config

Here is an example sim_config.json

{
    "sim_instance_name": "gt_gen_with_driver_and_kpi_logger",
    "activities": [
        {
            "name": "groundtruth_generator_activity",
            "is_world_simulator": true,
            "topics_cycling_info": [
                {
                    "topic_id": "__all__",
                    "topic_cycle_time_in_ms": 50
                }
            ],
            "type": "built-in"
        },
        {
            "name": "driver_model_activity",
            "depends_on": [
                "groundtruth_generator_activity"
            ],
            "type": "built-in"
        },
        {
            "name": "kpi_evaluator_activity",
            "depends_on": [
                "groundtruth_generator_activity"
            ],
            "type": "built-in"
        },
        {
            "name": "kpi_logger_activity",
            "depends_on": [
                "kpi_evaluator_activity"
            ],
            "type": "built-in"
        }
    ]
}

"sim_instance_name"

A name or a description for your simulation setup

"activities"

This section contains a list of activities that you can use in your simulation.

"name"

An identifier for the Activities that Simulation Framework core can query locally using ActivityFactory to instantiate them in the simulation.

"is_world_simulator"

A boolean flag that indicates whether this activity is used as a world simulator. Each simulation must have one world simulator activity, which generates environment inputs for all other simulation participants. This field is mandatory only if the activity is a world simulator, and the default value is set to false.

"topics_cycling_info"

This list describes the topic and its individual cycle time the user desires. This is a mandantory field for each activity, unless "depends_on" is specified.

"topic_id" A string identifier for the topic. Currently, multi-rate topics inside Simulation Framework are not supported yet. Use the specifier "_all_" to indicate all topics in this activity, and define their cycle time later in "topic_cycle_time_in_ms".
"topic_cycle_time_in_ms" An unsigned integer that describes the cycle time of the topic in milliseconds.

"depends_on"

This field allows you to create a dependency for the current activity on another activity specified by the user. Once a dependency is set up, "topics_cycling_info" is no longer mandatory for this activity. In this case, this activity will be stepped immediately after its dependent activity. If additional "topics_cycling_info" is also provided, this activity will be stepped only when its dependency has been stepped and the cycle time is reached.

"type"

This field indicates the location of the activity. "built-in" means that this is an activity pre-built in Activity Factory of Simulation Framework core. "standalone" means that this is a standalone activity running outside Simulation Framework as a dedicated process. During simulation startup, Simulation Framework core will try to connect with all required standalone Activities if they are given in the config.

Validation of simulation config

Before each simulation, the rules defined above will be validated by the parser. An error message will be thrown if any field contains an error or is defined against the rules.

AVxcelerate Simulation Framework 2024 R1