Scenario Reader

Read driving scenario into model

• Library:

• Automated Driving Toolbox / Driving Scenario and Sensor Modeling

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Description

The Scenario Reader block reads the roads and actors from a scenario file created using the Driving Scenario Designer app or from a drivingScenario object. The block outputs the poses of actors in either the coordinate system of the ego vehicle or the world coordinates of the scenario. You can also output the lane boundaries or output the ego vehicle pose for use in the 3D simulation environment.

To generate object and lane boundary detections from output actor poses and lane boundaries, pass the pose and boundary outputs to sensor blocks. Use the synthetic detections generated from these sensors to test the performance of sensor fusion algorithms, tracking algorithms, and other automated driving assistance system (ADAS) algorithms. To visualize the performance of these algorithms, use the Bird's-Eye Scope.

You can read the ego vehicle from the scenario or specify an ego vehicle defined in your model as an input to the Scenario Reader block. Use this option to test closed-loop vehicle controller algorithms, such as autonomous emergency braking (AEB), lane keeping assist (LKA), or adaptive cruise control (ACC).

Limitations

• The Scenario Reader block does not read sensor data from scenario files saved from the Driving Scenario Designer app. To reproduce sensors in Simulink^®, in the app, open the scenario file that contains the sensors. Then, from the app toolstrip, select Export > Export Sensor Simulink Model. Copy the generated sensor blocks into an existing model. Alternatively, select Export > Export Simulink Model and start a new model from the generated Scenario Reader block and sensor blocks.

• Large road networks, including OpenDRIVE^® road networks, can take up to several minutes to read into models.

Ports

Input

Ego Vehicle — Ego vehicle pose

Simulink bus containing MATLAB^® structure

Ego vehicle pose, specified as a Simulink bus containing a MATLAB structure.

The structure must have these fields.

Field	Description
ActorID	Scenario-defined actor identifier, specified as a positive integer.
Position	Position of actor, specified as a real-valued vector of the form [x y z]. Units are in meters.
Velocity	Velocity (v) of actor in the x- y-, and z-directions, specified as a real-valued vector of the form [vx vy vz]. Units are in meters per second.
Roll	Roll angle of actor, specified as a real-valued scalar. Units are in degrees.
Pitch	Pitch angle of actor, specified as a real-valued scalar. Units are in degrees.
Yaw	Yaw angle of actor, specified as a real-valued scalar. Units are in degrees.
AngularVelocity	Angular velocity (ω) of actor in the x-, y-, and z-directions, specified as a real-valued vector of the form [ωx ωy ωz]. Units are in degrees per second.

Output the ego vehicle pose when you are converting actors from ego vehicle coordinates to world coordinates for use in the 3D simulation environment. For example, see Visualize Sensor Data from Unreal Engine Simulation Environment.

Dependencies

To enable this port, set these parameters in this order:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Source of ego vehicle parameter to Input port.

Output

Actors — Scenario actor poses

Simulink bus containing MATLAB structure

Scenario actor poses, returned as a Simulink bus containing a MATLAB structure.

The structure has these fields.

Field	Description	Type
NumActors	Number of actors	Nonnegative integer
Time	Current simulation time	Real-valued scalar
Actors	Actor poses	NumActors-length array of actor pose structures

Each actor pose structure in Actors has these fields.

Field	Description
ActorID	Scenario-defined actor identifier, specified as a positive integer.
Position	Position of actor, specified as a real-valued vector of the form [x y z]. Units are in meters.
Velocity	Velocity (v) of actor in the x- y-, and z-directions, specified as a real-valued vector of the form [vx vy vz]. Units are in meters per second.
Roll	Roll angle of actor, specified as a real-valued scalar. Units are in degrees.
Pitch	Pitch angle of actor, specified as a real-valued scalar. Units are in degrees.
Yaw	Yaw angle of actor, specified as a real-valued scalar. Units are in degrees.
AngularVelocity	Angular velocity (ω) of actor in the x-, y-, and z-directions, specified as a real-valued vector of the form [ωx ωy ωz]. Units are in degrees per second.

The pose of the ego vehicle is excluded from the Actors array.

To return actor poses from the block, you must run the entire driving scenario simulation to completion.

Lane Boundaries — Scenario lane boundaries

Simulink bus containing MATLAB structure

Scenario lane boundaries, returned as a Simulink bus containing a MATLAB structure.

The structure has these fields.

Field	Description	Type
NumLaneBoundaries	Number of lane boundaries	Nonnegative integer
Time	Current simulation time	Real scalar
LaneBoundaries	Lane boundaries	NumLaneBoundaries-length array of lane boundary structures

Each lane boundary structure in LaneBoundaries has these fields.

Field	Description
Coordinates	Lane boundary coordinates, specified as a real-valued N-by-3 matrix, where N is the number of lane boundary coordinates. Lane boundary coordinates define the position of points on the boundary at specified longitudinal distances away from the ego vehicle, along the center of the road. In MATLAB, specify these distances by using the 'XDistance' name-value pair argument of the laneBoundaries function. In Simulink, specify these distances by using the Distances from ego vehicle for computing boundaries (m) parameter of the Scenario Reader block or the Distance from parent for computing lane boundaries parameter of the Simulation 3D Vision Detection Generator block. This matrix also includes the boundary coordinates at zero distance from the ego vehicle. These coordinates are to the left and right of the ego-vehicle origin, which is located under the center of the rear axle. Units are in meters.
Curvature	Lane boundary curvature at each row of the Coordinates matrix, specified as a real-valued N-by-1 vector. N is the number of lane boundary coordinates. Units are in radians per meter.
CurvatureDerivative	Derivative of lane boundary curvature at each row of the Coordinates matrix, specified as a real-valued N-by-1 vector. N is the number of lane boundary coordinates. Units are in radians per square meter.
HeadingAngle	Initial lane boundary heading angle, specified as a real scalar. The heading angle of the lane boundary is relative to the ego vehicle heading. Units are in degrees.
LateralOffset	Distance of the lane boundary from the ego vehicle position, specified as a real scalar. An offset to a lane boundary to the left of the ego vehicle is positive. An offset to the right of the ego vehicle is negative. Units are in meters.
BoundaryType	Type of lane boundary marking, specified as one of these values: 'Unmarked' — No physical lane marker exists 'Solid' — Single unbroken line 'Dashed' — Single line of dashed lane markers 'DoubleSolid' — Two unbroken lines 'DoubleDashed' — Two dashed lines 'SolidDashed' — Solid line on the left and a dashed line on the right 'DashedSolid' — Dashed line on the left and a solid line on the right
Strength	Saturation strength of the lane boundary marking, specified as a real scalar from 0 to 1. A value of 0 corresponds to a marking whose color is fully unsaturated. The marking is gray. A value of 1 corresponds to a marking whose color is fully saturated.
Width	Lane boundary width, specified as a positive real scalar. In a double-line lane marker, the same width is used for both lines and for the space between lines. Units are in meters.
Length	Length of dash in dashed lines, specified as a positive real scalar. In a double-line lane marker, the same length is used for both lines.
Space	Length of space between dashes in dashed lines, specified as a positive real scalar. In a dashed double-line lane marker, the same space is used for both lines.

The number of returned lane boundary structures depends on the Lane boundaries to output parameter value.

Dependencies

To enable this port, set these parameters in this order:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Lane boundaries to output parameter to Ego lane boundaries or All lane boundaries.

Ego Vehicle — Ego vehicle pose

Simulink bus containing MATLAB structure

Ego vehicle pose, returned as a Simulink bus containing a MATLAB structure.

The structure must contain these fields.

Field	Description
ActorID	Scenario-defined actor identifier, specified as a positive integer.
Position	Position of actor, specified as a real-valued vector of the form [x y z]. Units are in meters.
Velocity	Velocity (v) of actor in the x- y-, and z-directions, specified as a real-valued vector of the form [vx vy vz]. Units are in meters per second.
Roll	Roll angle of actor, specified as a real-valued scalar. Units are in degrees.
Pitch	Pitch angle of actor, specified as a real-valued scalar. Units are in degrees.
Yaw	Yaw angle of actor, specified as a real-valued scalar. Units are in degrees.
AngularVelocity	Angular velocity (ω) of actor in the x-, y-, and z-directions, specified as a real-valued vector of the form [ωx ωy ωz]. Units are in degrees per second.

Dependencies

To enable this port, set these parameters in this order:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Source of ego vehicle parameter to Scenario.

3. Select the Output ego vehicle pose parameter.

Parameters

Scenario

Source of driving scenario — Source of driving scenario

From file (default) | From workspace

Source of driving scenario, specified as one of these options:

• From file — In the Driving Scenario Designer file name parameter, specify the name of a scenario file that was saved from the Driving Scenario Designer app.

• From workspace — In the MATLAB or model workspace variable name parameter, specify the name of a MATLAB or model workspace variable that contains a drivingScenario object.

Driving Scenario Designer file name — Scenario file name

EgoVehicleGoesStraight.mat (default) | scenario file on MATLAB search path | path to scenario file

Scenario file name, specified as a scenario file on the MATLAB search path or as the full path to a scenario file. A scenario file must be a MAT-file saved from the Driving Scenario Designer app. If the Source of ego vehicle parameter is set to Scenario, then the scenario must contain an ego vehicle. Otherwise, the block returns an error during simulation.

If the specified scenario file contains sensors, the block ignores them. To include sensors from the scenario in your model, see Tips.

The default scenario file shows an ego vehicle traveling north on a straight, two-lane road, with another vehicle traveling south in the opposite lane.

To add a scenario file to the MATLAB search path, use the addpath function. For example, this code adds the set of folders containing prebuilt Euro NCAP^® scenarios to the MATLAB search path.

path = fullfile(matlabroot,'toolbox','driving','drivingdata', ...
    'PrebuiltScenarios','EuroNCAP');
addpath(genpath(path))

In the Driving Scenario Designer file name parameter, you can then specify the name of any scenario located in these folders, without having to specify the full file path. For example: AEB_PedestrianChild_Nearside_50width.mat.

When you are done using the scenario in your models, you can remove any added folders from the MATLAB search path by using the rmpath function.

rmpath(genpath(path))

Dependencies

To enable this parameter, set the Source of driving scenario parameter to From file.

MATLAB or model workspace variable name — Scenario variable name

scenario (default) | drivingScenario object variable name

Scenario variable name, specified as the name of a MATLAB or model workspace variable that contains a valid drivingScenario object. If a scenario variable with the same name appears in both the MATLAB and model workspace, the block uses the variable defined in the model workspace.

If the Source of ego vehicle parameter is set to Scenario, then the drivingScenario object must contain an ego vehicle. To designate which actor in the object is the ego vehicle, in the Ego vehicle ActorID parameter, specify the ActorID property value of that actor.

The default variable name, scenario, is the default name of drivingScenario objects produced by the MATLAB functions that are exported from the Driving Scenario Designer app. By default, this variable is not included in the MATLAB or model workspace.

Dependencies

To enable this parameter, set the Source of driving scenario parameter to From workspace.

Coordinate system of actors output — Coordinate system of actors output

Vehicle coordinates (default) | World coordinates

Coordinate system of the output actors, specified as one of these values:

• Vehicle coordinates — Coordinates are defined with respect to the ego vehicle. Select this value when your scenario has only one ego vehicle.

• World coordinates — Coordinates are defined with respect to the driving scenario. Select this value in multi-agent scenarios that contain more than one ego vehicle. If you select this value, model visualization using the Bird's-Eye Scope is not supported.

For more details on the vehicle and world coordinate systems, see Coordinate Systems in Automated Driving Toolbox.

Source of ego vehicle — Source of ego vehicle

Scenario (default) | Input port

Source of ego vehicle, specified as one of these options:

• Scenario — Use the ego vehicle defined in the scenario that is specified by the Driving Scenario Designer file name or MATLAB or model workspace variable name parameter. The pose of the ego vehicle is excluded from the Actors output port. Actor positions are in vehicle coordinates, meaning that they are relative to the world coordinate position of the ego vehicle in the scenario.

  Select this option to test open-loop ADAS algorithms, where the ego vehicle behavior is predefined and does not change as the scenario advances. For an example, see Test Open-Loop ADAS Algorithm Using Driving Scenario.

• Input port — Specify the ego vehicle by using the Ego Vehicle input port. The pose of the ego vehicle is not included in the Actors output port.

  With this option, the ego vehicle in your model must include a starting position that is in world coordinates. All other actor poses are in vehicle coordinates and are positioned relative to the ego vehicle. For an example of an ego vehicle with defined position information, see Lane Keeping Assist with Lane Detection. When defining the starting position of the ego vehicle, consider using the position that is already defined in the scenario. By using this position, if you set Source of ego vehicle to Scenario and then back to Input port, you do not have to manually change the starting position.

  Select this option to test closed-loop ADAS algorithms, where the ego vehicle reacts to changes as the scenario advances. For an example, see Test Closed-Loop ADAS Algorithm Using Driving Scenario.

Dependencies

To enable this parameter, set the Coordinate system of actors output parameter to Vehicle coordinates.

Ego vehicle ActorID — Actor ID of ego vehicle

1 (default) | positive integer

Actor ID of ego vehicle, specified as a positive integer. Use this parameter to simulate using the ego vehicle that is read from a drivingScenario object.

• When Source of ego vehicle is set to Scenario, set this parameter to an ActorID value that is stored in the Actors property of the specified drivingScenario object. To check valid ActorID values, use this syntax, where scenario is the name of the drivingScenario variable name.

  actorIDs = [scenario.Actors.ActorID]

• When Source of ego vehicle is set to Input Port, you must set this parameter to the ActorID value at the Ego Vehicle input port of the block.

Dependencies

To enable this parameter, set these parameters in this order:

1. Set the Source of driving scenario parameter to From workspace.

2. Set the Coordinate system of actors output parameter to Vehicle coordinates.

Output ego vehicle pose — Output pose of ego vehicle

off (default) | on

Select this parameter to output the pose of the ego vehicle at the Ego Vehicle port.

Dependencies

To enable this parameter, set the Coordinate system of actors output parameter to Vehicle coordinates and the Source of ego vehicle parameter to Scenario.

Ego vehicle follows ground — Orient ego vehicle to follow road surface

off (default) | on

Select this parameter to orient the ego vehicle to follow the elevation of the road surface. The block updates the elevation, roll, pitch, and yaw of the ego vehicle and outputs actors and lane boundaries relative to the updated ego vehicle coordinates. The block does not update the velocity or angular velocity of the ego vehicle.

Use this parameter in closed-loop simulations where the elevation of the road network varies.

Note

At the junctions of roads that have different elevations and banking angles, the updated ego vehicle values might not be accurate.

In open-loop simulations, where Source of ego vehicle is set to Scenario, the ego vehicle follows the elevation specified in the driving scenario.

Dependencies

To enable this parameter, set Coordinate system of actors output to Vehicle coordinates and Source of ego vehicle to Input port.

Sample time (s) — Sample time of simulation

0.1 (default) | positive real scalar

Sample time of simulation, in seconds, specified as a positive real scalar. Inherited and continuous sample times are not supported. This sample time is separate from the sample times that the Driving Scenario Designer app and drivingScenario object use during simulation.

Lanes

Lane boundaries to output — Lane boundaries to output

None (default) | Ego vehicle lane boundaries | All lane boundaries

Lane boundaries to output, specified as one of these options:

• None — Do not output any lane boundaries.

• Ego vehicle lane boundaries — Output the left and right lane boundaries of the ego vehicle.

• All lane boundaries — Output all lane boundaries of the road on which the ego vehicle is traveling.

If you select Ego vehicle lane boundaries or All lane boundaries, then the block returns the lane boundaries in the Lane Boundaries output port.

Dependencies

To enable this parameter, set the Coordinate system of actors output parameter to Vehicle coordinates.

Distances from ego vehicle for computing boundaries (m) — Distances from ego vehicle at which to compute lane boundaries

linspace(-150,150,101) (default) | N-element real-valued vector

Distances from the ego vehicle at which to compute the lane boundaries, specified as an N-element real-valued vector. N is the number of distance values. When detecting lanes from rear-facing cameras, specify negative distances. When detecting lanes from front-facing cameras, specify positive distances. Units are in meters.

By default, the block computes 101 lane boundaries over the range from 150 meters behind the ego vehicle to 150 meters ahead of the ego vehicle. These distances are linearly spaced 3 meters apart.

Example: 1:0.1:10 computes a lane boundary every 0.1 meters over the range from 1 to 10 meters ahead of the ego vehicle.

Dependencies

To enable this parameter, set the Lane boundaries to output parameter to Ego vehicle lane boundaries or All lane boundaries.

Location of boundaries on lane markings — Lane boundary location

Center of lane markings (default) | Inner edge of lane markings

Lane boundary location on the lane markings, specified as one of the options in this table.

Lane Boundary Location	Description	Example
Center of lane markings	Lane boundaries are centered on the lane markings.	A three-lane road has four lane boundaries: one per lane marking.
Inner edge of lane markings	Lane boundaries are placed at the inner edges of the lane markings.	A three-lane road has six lane boundaries: two per lane.

Dependencies

To enable this parameter, set the Lane boundaries to output parameter to Ego vehicle lane boundaries or All lane boundaries.

Port Settings

Source of actors bus name — Source of name for actor poses bus

Auto (default) | Property

Source of the name for the actor poses bus returned in the Actors output port, specified as one of these options:

• Auto — The block automatically creates an actor poses bus name.

• Property — Specify the actor poses bus name by using the Actors bus name parameter.

Actors bus name — Name of actor poses bus

valid bus name

Name of the actor poses bus returned in the Actors output port, specified as a valid bus name.

Dependencies

To enable this parameter, set Source of actors bus name to Property.

Source of maximum number of actors — Source of maximum number of actors

Scenario (default) | Property

Source of the maximum number of actors that you can have in the driving scenario, specified as one of these options:

• Scenario — The block sets the maximum number of actors to the number of actors in the driving scenario. This value is equal to the NumActors field of the bus returned by the Actors output port. When you change the input scenario, the maximum number of actors updates to match the new NumActors value.

• Property — Specify the maximum number of actors by using the Maximum number of actors parameter. Select this option when you want to reuse the same actor bus across scenarios that have varying numbers of actors, such as when outputting actors from a referenced model.

Maximum number of actors — Maximum number of actors

100 (default) | positive integer

Maximum number of actors that you can have in the scenario, specified as a positive integer.

Dependencies

To enable this parameter, set the Source of maximum number of actors parameter to Property.

Source of lane boundaries bus name — Source of name for lane boundaries bus

Auto (default) | Property

Source of the name for the lane boundaries bus returned in the Lane Boundaries output port, specified as one of these options:

• Auto — The block automatically creates a lane boundaries bus name.

• Property — Specify the lane boundaries bus name by using the Lane boundaries bus name parameter.

Dependencies

To enable this parameter:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Lane boundaries to output parameter to Ego vehicle lane boundaries or All lane boundaries.

Lane boundaries bus name — Name of lane boundaries bus

valid bus name

Name of the lane boundaries bus returned in the Lane Boundaries output port, specified as a valid bus name.

Dependencies

To enable this parameter:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Lane boundaries to output parameter to Ego vehicle lane boundaries or All lane boundaries.

3. Set the Source of lane boundaries bus name parameter to Property.

Source of maximum number of lane boundaries — Source of maximum number of lane boundaries

Scenario (default) | Property

Source of the maximum number of lane boundaries that you can have in the driving scenario, specified as one of these options:

• Scenario — The block sets the maximum number of lane boundaries to the number of lane boundaries in the driving scenario. This value is equal to the NumLaneBoundaries field of the bus returned by the Lane Boundaries output port. When you change the input scenario, the maximum number of lane boundaries updates to match the new NumLaneBoundaries value.

• Property — Specify the maximum number of lane boundaries by using the Maximum number of lane boundaries parameter. Select this option when you want to reuse the same lane boundaries bus across scenarios that have varying numbers of lane boundaries, such as when outputting lane boundaries from a referenced model.

Dependencies

To enable this parameter:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Lane boundaries to output parameter to All lane boundaries.

Maximum number of lane boundaries — Maximum number of lane boundaries

10 (default) | positive integer

Maximum number of lane boundaries that you can have in the scenario, specified as a positive integer.

Dependencies

To enable this parameter:

1. Set the Coordinate system of actors output parameter to Vehicle coordinates.

2. Set the Lane boundaries to output parameter to All lane boundaries.

3. Set the Source of maximum number of lane boundaries parameter to Property.

Source of ego vehicle bus name — Source of name for ego vehicle pose bus

Auto (default) | Property

Source of the name for the ego vehicle pose bus returned in the Ego Vehicle output port, specified as one of these options:

• Auto — The block automatically creates an ego vehicle pose bus name.

• Property — Specify the ego vehicle pose bus name by using the Ego vehicle bus name parameter.

Dependencies

To enable this parameter, select the Output ego vehicle pose parameter.

Ego vehicle bus name — Name of ego vehicle pose bus

valid bus name

Name of the ego vehicle pose bus returned in the Ego Vehicle output port, specified as a valid bus name.

Dependencies

To enable this parameter, select the Output ego vehicle pose parameter and set the Source of ego vehicle bus name parameter to Property.

Show coordinate labels — Display coordinate system of inputs and outputs

on (default) | off

Select this parameter to display the coordinate system of block inputs and outputs on the Scenario Reader block in the block diagram.

• The Ego Vehicle input and output are always in world coordinates.

• The Lane Boundaries output is always in vehicle coordinates.

• You can return the Actors output in either vehicle or world coordinates, depending on the Coordinate system of actors output parameter selection.

Simulation

Simulate using — Type of simulation to run

Interpreted execution (default) | Code generation

• Interpreted execution — Simulate the model using the MATLAB interpreter. This option shortens startup time. In Interpreted execution mode, you can debug the source code of the block.

• Code generation — Simulate the model using generated C/C++ code. The first time you run a simulation, Simulink generates C/C++ code for the block. The C code is reused for subsequent simulations as long as the model does not change. This option requires additional startup time.

Model Examples

Test Open-Loop ADAS Algorithm Using Driving Scenario

Test open-loop ADAS algorithms in Simulink by using driving scenarios saved from the Driving Scenario Designer app.

Test Closed-Loop ADAS Algorithm Using Driving Scenario

Test closed-loop ADAS algorithms in Simulink by using driving scenarios saved from the Driving Scenario Designer app.

Create Driving Scenario Variations Programmatically

Programmatically create variations of a driving scenario that was built using the Driving Scenario Designer app.

Generate Sensor Blocks Using Driving Scenario Designer

Generate Simulink blocks for a driving scenario and sensors that were built using the Driving Scenario Designer app.

Visualize Sensor Data from Unreal Engine Simulation Environment

Visualize sensor coverage areas and detections obtained from high-fidelity radar and lidar sensors in the Unreal Engine^® simulation environment.

Tips

• For best results, use only one active Scenario Reader block per model. To use multiple Scenario Reader blocks in one model, switch between the blocks by specifying them in a variant subsystem.

• To test your algorithm on variations of a driving scenario, you can update the scenario between simulations.

  • If the source of the scenario is a scenario file, open the scenario file in the Driving Scenario Designer app, update the parameters, and resave the file.

  • If the source of the scenario is a drivingScenario object, update the object in the MATLAB or model workspace. Alternatively, import the object into the app, modify the scenario in the app, and then generate a new object from the app. For more details, see Create Driving Scenario Variations Programmatically.

• To switch between scenarios with different parameter settings, you can use Simulink Test™ software. For an example, see Automate Testing for Highway Lane Following.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

Usage notes and limitations:

• When a model is in rapid accelerator mode, the Scenario Reader block does not automatically regenerate code based on changes made to the driving scenario between simulations. To regenerate these changes, manually delete the Simulink project folder, slprj, that was generated from the previous simulation. Then, rerun the simulation. Alternatively, either change modes or disable code generation by setting the Simulate using parameter to Interpreted execution.

• The Driving Scenario Designer file name and MATLAB or model workspace variable name parameters are character vectors. The limitations described in Encoding of Characters in Code Generation (Simulink) apply to these parameters.