Simulation 3D Probabilistic Radar
Probabilistic radar sensor model in 3D simulation environment
- Library:
Automated Driving Toolbox / Simulation 3D
Description
The Simulation 3D Probabilistic Radar block provides an interface to the probabilistic radar sensor in a 3D simulation environment. This environment is rendered using the Unreal Engine® from Epic Games®. You can specify the radar model and accuracy, bias, and detection parameters. The block uses the sample time to capture the radar detections and outputs a list of object detection reports. To configure the probabilistic radar signatures of actors in the 3D environment across all radars in your model, use a Simulation 3D Probabilistic Radar Configuration block.
If you set Sample time to -1, the block uses the
sample time specified in the Simulation 3D Scene Configuration block. To use
this sensor, you must include a Simulation 3D Scene Configuration block in your
model.
Note
The Simulation 3D Scene Configuration block must execute before the Simulation 3D Probabilistic Radar block. That way, the Unreal Engine 3D visualization environment prepares the data before the Simulation 3D Probabilistic Radar block receives it. To check the block execution order, right-click the blocks and select Properties. On the General tab, confirm these Priority settings:
Simulation 3D Scene Configuration —
0Simulation 3D Probabilistic Radar —
1
For more information about execution order, see How Unreal Engine Simulation for Automated Driving Works.
Ports
Output
Parameters
Mounting
Sensor identifier — Unique sensor identifier
1 (default) | positive integer
Unique sensor identifier, specified as a positive integer. In a multisensor system, the sensor identifier distinguishes between sensors. When you add a new sensor block to your model, the Sensor identifier of that block is N + 1. N is the highest Sensor identifier value among existing sensor blocks in the model.
Example: 2
Parent name — Name of parent to which sensor is mounted
Scene Origin (default) | vehicle name
Name of the parent to which the sensor is mounted, specified as Scene Origin or as the name of a vehicle in your model. The vehicle names that you can select correspond to the Name parameters of the Simulation 3D Vehicle with Ground Following blocks in your model. If you select Scene Origin, the block places a sensor at the scene origin.
Example: SimulinkVehicle1
Mounting location — Sensor mounting location
Origin (default) | Front bumper | Rear bumper | Right mirror | Left mirror | Rearview mirror | Hood center | Roof center
Sensor mounting location.
When Parent name is
Scene Origin, the block mounts the sensor to the origin of the scene. You can set the Mounting location toOriginonly. During simulation, the sensor remains stationary.When Parent name is the name of a vehicle (for example,
SimulinkVehicle1) the block mounts the sensor to one of the predefined mounting locations described in the table. During simulation, the sensor travels with the vehicle.
| Vehicle Mounting Location | Description | Orientation Relative to Vehicle Origin [Roll, Pitch, Yaw] (deg) |
|---|---|---|
Origin | Forward-facing sensor mounted to the vehicle origin, which is on the ground, at the geometric center of the vehicle (see Coordinate Systems for Unreal Engine Simulation in Automated Driving Toolbox)
| [0, 0, 0] |
Front bumper | Forward-facing sensor mounted to the front bumper
| [0, 0, 0] |
Rear bumper | Backward-facing sensor mounted to the rear bumper
| [0, 0, 180] |
Right mirror | Downward-facing sensor mounted to the right side-view mirror
| [0, –90, 0] |
Left mirror | Downward-facing sensor mounted to the left side-view mirror
| [0, –90, 0] |
Rearview mirror | Forward-facing sensor mounted to the rearview mirror, inside the vehicle
| [0, 0, 0] |
Hood center | Forward-facing sensor mounted to the center of the hood
| [0, 0, 0] |
Roof center | Forward-facing sensor mounted to the center of the roof
| [0, 0, 0] |
Roll, pitch, and yaw are clockwise-positive when looking in the positive direction of the X-axis, Y-axis, and Z-axis, respectively. When looking at a vehicle from the top down, the yaw angle (that is, the orientation angle) is counterclockwise-positive, because you are looking in the negative direction of the axis.
The (X, Y, Z) mounting location of the sensor relative to the vehicle depends on the vehicle type. To specify the vehicle type, use the Type parameter of the Simulation 3D Vehicle with Ground Following block to which you are mounting the sensor. To obtain the (X, Y, Z) mounting locations for a vehicle type, see the reference page for that vehicle.
To determine the location of the sensor in world coordinates, open the sensor block. Then, on the Ground Truth tab, select Output location (m) and orientation (rad) and inspect the data from the Location output port.
Specify offset — Specify offset from mounting location
off (default) | on
Select this parameter to specify an offset from the mounting location by using the Relative translation [X, Y, Z] (m) and Relative rotation [Roll, Pitch, Yaw] (deg) parameters.
Relative translation [X, Y, Z] (m) — Translation offset relative to mounting location
[0, 0, 0] (default) | real-valued 1-by-3 vector
Translation offset relative to the mounting location of the sensor, specified as a real-valued 1-by-3 vector of the form [X, Y, Z]. Units are in meters.
If you mount the sensor to a vehicle by setting Parent name to the name of that vehicle, then X, Y, and Z are in the vehicle coordinate system, where:
The X-axis points forward from the vehicle.
The Y-axis points to the left of the vehicle, as viewed when looking in the forward direction of the vehicle.
The Z-axis points up.
The origin is the mounting location specified in the Mounting location parameter. This origin is different from the vehicle origin, which is the geometric center of the vehicle.
If you mount the sensor to the scene origin by setting Parent name to Scene Origin, then X, Y, and Z are in the world coordinates of the scene.
For more details about the vehicle and world coordinate systems, see Coordinate Systems for Unreal Engine Simulation in Automated Driving Toolbox.
Example: [0,0,0.01]
Dependencies
To enable this parameter, select Specify offset.
Relative rotation [Roll, Pitch, Yaw] (deg) — Rotational offset relative to mounting location
[0, 0, 0] (default) | real-valued 1-by-3 vector
Rotational offset relative to the mounting location of the sensor, specified as a real-valued 1-by-3 vector of the form [Roll, Pitch, Yaw] . Roll, pitch, and yaw are the angles of rotation about the X-, Y-, and Z-axes, respectively. Units are in degrees.
If you mount the sensor to a vehicle by setting Parent name to the name of that vehicle, then X, Y, and Z are in the vehicle coordinate system, where:
The X-axis points forward from the vehicle.
The Y-axis points to the left of the vehicle, as viewed when looking in the forward direction of the vehicle.
The Z-axis points up.
Roll, pitch, and yaw are clockwise-positive when looking in the forward direction of the X-axis, Y-axis, and Z-axis, respectively. If you view a scene from a 2D top-down perspective, then the yaw angle (also called the orientation angle) is counterclockwise-positive because you are viewing the scene in the negative direction of the Z-axis.
The origin is the mounting location specified in the Mounting location parameter. This origin is different from the vehicle origin, which is the geometric center of the vehicle.
If you mount the sensor to the scene origin by setting Parent name to Scene Origin, then X, Y, and Z are in the world coordinates of the scene.
For more details about the vehicle and world coordinate systems, see Coordinate Systems for Unreal Engine Simulation in Automated Driving Toolbox.
Example: [0,0,10]
Dependencies
To enable this parameter, select Specify offset.
Sample time — Sample time
-1 (default) | positive scalar
Sample time of the block in seconds, specified as a positive scalar. The 3D simulation environment frame rate is the inverse of the sample time.
If you set the sample time to -1, the block inherits its sample time from the Simulation 3D Scene Configuration block.
Parameters
Accuracy SettingsAzimuthal resolution of radar (deg) — Azimuth resolution of radar
4 (default) | positive real scalar
Azimuth resolution of the radar, specified as a positive real scalar. The azimuth resolution defines the minimum separation in azimuth angle at which the radar can distinguish between two targets. The azimuth resolution is typically the 3dB-downpoint in azimuth angle beamwidth of the radar. Units are in degrees.
Example: 6.5
Elevation resolution of radar (deg) — Elevation resolution of radar
10 (default) | positive real scalar
Elevation resolution of the radar, specified as a positive real scalar. The elevation resolution defines the minimum separation in elevation angle at which the radar can distinguish between two targets. The elevation resolution is typically the 3dB-downpoint in elevation angle beamwidth of the radar. Units are in degrees.
Example: 3.5
Dependencies
To enable this parameter, on the Parameters tab, in the Radar model section, select Enable elevation angle measurements.
Range resolution of radar (m) — Range resolution of radar
2.5 (default) | positive real scalar
Range resolution of the radar, specified as a positive real scalar. The range resolution defines the minimum separation in range at which the radar can distinguish between two targets. Units are in meters.
Example: 5.0
Range rate resolution of radar (m/s) — Range rate resolution of the radar
0.5 (default) | positive real scalar
Range rate resolution of the radar, specified as a positive real scalar. The range rate resolution defines the minimum separation in range rate at which the radar can distinguish between two targets. Units are in meters per second.
Example: 0.75
Dependencies
To enable this parameter, on the Parameters tab, in the Radar model section, select Enable range rate measurements.
Fractional azimuthal bias component — Azimuth bias fraction
0.1 (default) | nonnegative real scalar
Azimuth bias fraction of the radar, specified as a nonnegative real scalar. The azimuth bias is expressed as a fraction of the azimuth resolution specified in the Azimuthal resolution of radar (deg) parameter. Units are dimensionless.
Example: 0.3
Fractional elevation bias component — Elevation bias fraction
0.1 (default) | nonnegative real scalar
Elevation bias fraction of the radar, specified as a nonnegative real scalar. The elevation bias is expressed as a fraction of the elevation resolution specified in the Elevation resolution of radar (deg) parameter. Units are dimensionless.
Example: 0.2
Dependencies
To enable this parameter, on the Parameters tab, in the Radar model section, select Enable elevation angle measurements.
Fractional range bias component — Range bias fraction
0.05 (default) | nonnegative real scalar
Range bias fraction of the radar, specified as a nonnegative real scalar. Range bias is expressed as a fraction of the range resolution specified in the Range resolution of radar (m) parameter. Units are dimensionless.
Example: 0.15
Fractional range rate bias component — Range rate bias fraction
0.05 (default) | nonnegative real scalar
Range rate bias fraction of the radar, specified as a nonnegative real scalar. Range rate bias is expressed as a fraction of the range rate resolution specified in the Range rate resolution of radar (m/s) parameter. Units are dimensionless.
Example: 0.2
Dependencies
To enable this parameter, on the Parameters tab, in the Radar model section, select Enable range rate measurements.
Field of view (deg) — Field of view
[20, 5] (default) | positive real-valued 1-by-2 vector
Field of view of the radar, specified as a positive real-valued 1-by-2 vector of
the form [azfov, elfov]. azfov is the azimuth
angle field of view. elfov is the elevation
angle field of view. The field of view defines the angular extent spanned by the
sensor. Each component must lie in the interval (0,180]. Targets outside of the field
of view of the radar are not detected. Units are in degrees.
Example: [14 7]
Detection ranges (m) — Detection range
[1, 150] (default) | positive real-valued 1-by-2 vector
Detection range, in meters, at which the radar can detect a target.
To set only a maximum detection range, specify this parameter as a positive real scalar. By default, the minimum detection range is 0.
To set both a minimum and maximum detection range, specify this parameter as a positive real-valued 1-by-2 vector of the form
[min, max].
Example: 250
Range rates (m/s) — Minimum and maximum detection range rates
[-100, 100] (default) | real-valued 1-by-2 vector
Minimum and maximum detection range rates, specified as a real-valued 1-by-2 vector. The radar can detect targets only within this range rate interval. Units are in meters per second.
Example: [-200 200]
Dependencies
To enable this parameter, on the Parameters tab, in the Radar model section, select Enable range rate measurements.
Detection probability — Probability that radar detects a target
0.9 (default) | real scalar in the range (0, 1]
Probability that the radar detects a target, specified as a real scalar in the range (0, 1]. This quantity defines the probability of detecting a target that has a radar cross section specified by the Reference radar cross section (dBsm) parameter, at the reference detection range specified by the Detection ranges (m) parameter.
Example: 0.95
False alarm rate — False alarm rate
1e-6 (default) | positive real scalar in range [10–7,
10–3]
False alarm rate within a radar resolution cell, specified as a positive real scalar in the range [10–7, 10–3]. Units are dimensionless.
Example: 1e-5
Detection probability range (m): — Reference range for given probability of detection
100 (default) | positive real scalar
Reference range for a given probability of detection, specified as a positive real scalar. The reference range is the range at which the radar detects targets that have a radar cross section specified by Reference radar cross section (dBsm), given a detection probability specified by Detection probability. Units are in meters.
Example: 150
Reference radar cross section (dBsm) — Reference radar cross section for given probability of detection
0 (default) | nonnegative real scalar
Reference radar cross section (RCS) for a given probability of detection, specified as a nonnegative real scalar. A radar with the detection probability specified by Detection probability detects targets at this reference RCS value. Units are in decibels per square meter.
Example: 2.0
Enable elevation angle measurements — Enable radar to measure elevation
on (default) | off
Select this parameter to model a radar that can measure target elevation angles. This parameter enables the Elevation resolution of radar (deg) and Fractional elevation bias component parameters.
Enable range rate measurements — Enable radar to measure range rate
on (default) | off
Select this parameter to model a radar that can measure target range rates. This parameter enables the Range rate resolution of radar (m/s), Fractional range bias component, and Range rates (m/s) parameters.
Enable measurement noise — Enable adding noise to radar sensor measurements
on (default) | off
Select this parameter to add noise to radar sensor measurements. Otherwise, the
measurements are noise-free. The MeasurementNoise property of
each detection is always computed and is not affected by the value you specify for the
Measurement noise parameter. By not selecting this parameter,
you can pass the sensor ground truth measurements into a Multi-Object
Tracker block.
Enable false detections — Enable reporting false alarm radar detections
on (default) | off
Select this parameter to enable reporting false alarm radar measurements. Otherwise, only actual detections are reported.
Random number generator method — Method to set random number generator seed
Repeatable (default) | Specify seed | Not repeatable
Method to set the random number generator seed, specified as one of the options in the table.
| Option | Description |
|---|---|
Repeatable | The block generates a random initial seed for the first
simulation and reuses this seed for all subsequent simulations. Select
this parameter to generate repeatable results from the statistical sensor
model. To change this initial seed, at the MATLAB command prompt, enter |
Specify seed | Specify your own random initial seed for reproducible results by using the Specify seed parameter. |
Not repeatable | The block generates a new random initial seed after each simulation run. Select this parameter to generate nonrepeatable results from the statistical sensor model. |
Initial seed — Random number generator seed
0 (default) | scalar in range [0, 232)
Random number generator seed, specified as a scalar in the range [0, 232)
Example: 2001
Dependencies
To enable this parameter, set the Random number generator
method parameter to Specify seed.
Maximum reported — Maximum number of reported detections
50 (default) | positive integer
Maximum number of reported detections, specified as a positive integer. Units are dimensionless.
Example: 35
Coordinate system — Coordinate system of reported detections
Ego Cartesian (default) | Sensor Cartesian | Sensor spherical
Coordinate system of reported detections, specified as one of these values:
Ego Cartesian— The radar reports detections in the ego vehicle Cartesian coordinate system.Sensor Cartesian— The radar reports detections in the sensor Cartesian coordinate system.Sensor spherical— The radar reports detections in the spherical coordinate system. This coordinate system is centered at the radar and aligned with the orientation of the radar on the ego vehicle.
Specify output bus name — Specify name of output bus
off (default) | on
Select this parameter to specify the name of the bus that the block outputs to the base workspace. Specify this name in the Output bus name parameter.
Output bus name — Name of output bus
BusSimulation3DRadarTruthSensor (default) | valid bus name
Name of the bus that the block outputs to the base workspace.
Dependencies
To enable this parameter, select the Specify output bus name parameter.
Model Examples
Tips
To visualize detections and sensor coverage areas, use the Bird's-Eye Scope. For more details, see Visualize Sensor Data from Unreal Engine Simulation Environment.
Because the Unreal Engine can take a long time to start between simulations, consider logging the signals that the sensors output. For more details, see Configure a Signal for Logging (Simulink).
References
[1] Blacksmith, P., R. E. Hiatt, and R. B. Mack. "Introduction to radar cross-section measurements." Proceedings of the IEEE. Volume 53, No. 8, August 1965, pp. 901–920. doi: 10.1109/PROC.1965.4069.