Gazebo Engine Configuration

Here you can find the experiment configuration file parameters description and schema for the Gazebo Engine.

Engine Configuration Parameters

This Engine type parameters are defined in GazeboGRPCEngine schema (listed here), which in turn is based on EngineBase and EngineGRPC schemas and thus inherits all parameters from them.

To use the Gazebo engine in an experiment, set EngineType to “gazebo_grpc”.

• Parameters inherited from EngineBase schema:

Name	Description	Type	Default	Required	Array
EngineName	Name of the engine	string		X
EngineType	Engine type. Used by	string		X
EngineProcCmd	Engine Process Launch command	string
EngineProcStartParams	Engine Process Start Parameters	string	[]		X
EngineEnvParams	Engine Process Environment Parameters	string	[]		X
EngineLaunchCommand		object	{“LaunchType”:”BasicFork”}
EngineTimestep	Engine Timestep in seconds	number	0.01
EngineCommandTimeout	Engine Timeout (in seconds). It tells how long to wait for the completion of the engine runStep. 0 or negative values are interpreted as no timeout	number	0.0

• Parameters inherited from the EngineGRPC schema:

Name	Description	Type	Default	Required	Array
ServerAddress	gRPC Server address. Should this address already be in use, simulation initialization will fail	string	localhost:9004

• Parameters specific to this engine type:

Name	Description	Type	Default	Required	Array
GazeboWorldFile	Path to Gazebo SDF World file	string		X
GazeboSDFModels	Additional models to be spawn in the Gazebo simulation. The elements of this array should be of type		[]		X
GazeboPlugins	Additional system plugins that should be loaded on startup	string	[]		X
GazeboRNGSeed	Seed parameters passed to gzserver start command	integer	0
WorldLoadTime	Maximum time (in seconds) to wait for the NRPCommunicationPlugin to load the world sdf file. 0 means it will wait indefinitely	integer	20

• Parameters of GazeboSDFModel:

Name	Description	Type	Default	Required	Array
Name	Name of the model	string		X
File	Path to Gazebo SDF file describing the model	string		X
InitPose	Array of six elements describing the model initial pose as a space separated 6-tuple: x y z roll pitch yaw	string	“0 0 0 0 0 0”

Schema

As explained above, the schema used by the Gazebo engine inherits from EngineBase and EngineGRPC schemas. A complete schema for the configuration of this engine is given below:

{ "gazebo_sdf_model" : {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "Gazebo SDF Model",
    "description": "Additional gazebo models to be spawn in a gazebo simulation",
    "$id": "#GazeboSDFModel",
    "properties" : {
      "Name": {
        "type": "string",
        "description": "Name of the model"
      },
      "File": {
        "type": "string",
        "description": "Path to Gazebo SDF file describing the model"
      },
      "InitPose": {
        "type": "string",
        "description": "Array of six elements describing the model initial pose as a space separated 6-tuple: x y z roll pitch yaw.",
        "default": "0 0 0 0 0 0"
      }
    },
    "required": ["Name", "File"]
  },
  "engine_gazebo_base" : {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "Gazebo Base",
    "description": "Gazebo Base Engine configuration schema. Configuration for all gazebo engine implementations inherit from this one",
    "$id": "#GazeboBase",
    "properties" : {
      "GazeboWorldFile": {
        "type": "string",
        "description": "Path to Gazebo SDF World file"
      },
      "GazeboSDFModels": {
        "type": "array",
        "items": {"$ref": "#/gazebo_sdf_model"},
        "description": "Additional models to be spawn in the Gazebo simulation"
      },
      "GazeboPlugins": {
        "type": "array",
        "items": {"type": "string"},
        "description": "Additional system plugins that should be loaded on startup"
      },
      "GazeboRNGSeed": {
        "type": "integer",
        "default": 0,
        "description": "Seed parameters passed to gzserver start command"
      },
      "WorldLoadTime": {
        "type": "integer",
        "default": 20,
        "description": "Maximum time (in seconds) to wait for the NRPCommunicatioPlugin to load the world sdf file. 0 means it will wait indefinitely"
      }
    },
    "required": ["GazeboWorldFile"]
  },
  "engine_gazebo_grpc" : {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "Gazebo Grpc Engine",
    "description": "Gazebo Grpc Engine",
    "$id": "#GazeboGRPCEngine",
    "allOf": [
      { "$ref": "json://nrp-core/engines/engine_comm_protocols.json#/engine_grpc" },
      { "$ref": "#/engine_gazebo_base" },
      {
        "properties": {
          "EngineType": { "enum": ["gazebo_grpc"] },
          "EngineProcCmd": { "default": "/usr/bin/gzserver" },
          "ProtobufPackages": { "default": ["Gazebo"]}
        }
      }
    ]
  },
  "engine_gazebo_json" : {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "Gazebo Json Engine",
    "description": "Gazebo Json Engine",
    "$id": "#GazeboJSONEngine",
    "allOf": [
      { "$ref": "json://nrp-core/engines/engine_comm_protocols.json#/engine_json" },
      { "$ref": "#/engine_gazebo_base" },
      {
        "properties": {
          "EngineType": { "enum": ["gazebo_json"] },
          "EngineProcCmd": { "default": "/usr/bin/gzserver" }
        }
      }
    ]
  }
}