Simulation 3D Vehicle with Ground Following

Implement vehicle that follows ground in 3D environment

Since R2024a

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Libraries:
Automated Driving Toolbox / Simulation 3D
Vehicle Dynamics Blockset / Vehicle Scenarios / Sim3D / Sim3D Vehicle / Components
Simulink 3D Animation / Simulation 3D / Actors

Description

The Simulation 3D Vehicle with Ground Following block implements a vehicle with four wheels in a 3D simulation environment. This environment is rendered using the Unreal Engine^® from Epic Games^®. The block uses the input (X, Y) position and yaw angle of the vehicle to adjust the elevation, roll angle, and pitch angle of the vehicle so that it follows the ground terrain. The block determines the vehicle velocity and heading and adjusts the steering angle and rotation for each wheel. Use this block for automated driving applications.

To use this block, ensure that the Simulation 3D Scene Configuration block is in your model. If you set the Sample time parameter of the Simulation 3D Vehicle with Ground Following block to -1, the block inherits the sample time specified in the Simulation 3D Scene Configuration block.

The block input uses the vehicle Z-up right-handed (RH) Cartesian coordinate system defined in SAE J670 [1] and ISO 8855 [2]. The coordinate system is inertial and initially aligned with the vehicle geometric center:

• The X-axis is along the longitudinal axis of the vehicle and points forward.

• The Y-axis is along the lateral axis of the vehicle and points to the left.

• The Z-axis points upward.

The yaw, pitch, and roll angles of the Z-axis, Y-axis, and X-axis, respectively, are positive in the clockwise directions, when looking in the positive directions of these axes. Vehicles are placed in the world coordinate system of the scenes. For more details, see Coordinate Systems for Unreal Engine Simulation in Automated Driving Toolbox (Automated Driving Toolbox).

Tip

The Simulation 3D Vehicle with Ground Following block must execute before the Simulation 3D Scene Configuration block. That way, the Simulation 3D Vehicle with Ground Following block prepares the signal data before the Unreal Engine 3D visualization environment 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 — 0

• Simulation 3D Vehicle with Ground Following — -1

For more information about execution order, see Control and Display Execution Order (Simulink).

You can configure the Simulation 3D Vehicle with Ground Following block to import custom meshes and control vehicle lights.

Ports

Input

X — Longitudinal position of vehicle

scalar

Longitudinal position of the vehicle along the X-axis of the scene. X is in the inertial Z-up coordinate system. Units are in meters.

Y — Lateral position of vehicle

scalar

Lateral position of the vehicle along the Y-axis of the scene. Y is in the inertial Z-up coordinate system. Units are in meters.

Yaw — Yaw orientation angle of vehicle

scalar

Yaw orientation angle of the vehicle along the Z-axis of the scene. Yaw is in the Z-up coordinate system. Units are in degrees.

The yaw value of the Initial rotation [Roll, Pitch, Yaw] (deg) parameter must match the value of this port at the start of simulation.

Light controls — Vehicle light controls

1-by-6 vector

Light controls input signal, specified as a 1-by-6 Boolean vector. Each element of the vector turns a specific vehicle light on or off, as indicated in this table. A value of 1 turns the light on; a value of 0 turns the light off.

Vector Element	Vehicle Light
(1,1)	Headlight high beam
(1,2)	Headlight low beam
(1,3)	Brake
(1,4)	Reverse
(1,5)	Left signal
(1,6)	Right signal

Dependencies

To create this port, on the Light Controls tab, select Enable light controls.

Data Types: Boolean

Parameters

Vehicle Parameters

Type — Type of vehicle

Muscle car (default) | Sedan | Sport utility vehicle | Small pickup truck | Hatchback | Box truck | Custom

Select the type of vehicle. To obtain the dimensions of each vehicle type, see these reference pages:

• Muscle car — Muscle Car (Automated Driving Toolbox)

• Sedan — Sedan (Automated Driving Toolbox)

• Sport utility vehicle — Sport Utility Vehicle (Automated Driving Toolbox)

• Small pickup truck — Small Pickup Truck (Automated Driving Toolbox)

• Hatchback — Hatchback (Automated Driving Toolbox)

• Box truck —Box Truck (Automated Driving Toolbox)

Dependencies

Selecting Custom enables parameters that allow you to import a custom mesh for your vehicle.

Path to custom mesh — Path to custom mesh

/MathWorksSimulation/Vehicles/Muscle/Meshes/SK_MuscleCar.SK_MuscleCar (default) | valid path

Path to custom mesh.

To create a custom vehicle mesh, see Prepare Custom Vehicle Mesh for the Unreal Editor (Automated Driving Toolbox).

Example: /MathWorksSimulation/Vehicles/Muscle/Meshes/SK_Sedan.SK_Sedan

Dependencies

To enable this parameter, set Type to Custom.

Track width in custom mesh (m) — Track width

1.9 (default) | scalar

Track width in custom mesh, in m.

Dependencies

To enable this parameter, set Type to Custom.

Wheel base in custom mesh (m) — Wheel base

3 (default) | scalar

Wheel base in custom mesh, in m.

Dependencies

To enable this parameter, set Type to Custom.

Wheel radius in custom mesh (m) — Wheel radius

0.35 (default) | scalar

Wheel radius in custom mesh, in m.

Dependencies

To enable this parameter, set Type to Custom.

Color — Color of vehicle

Red (default) | Orange | Yellow | Green | Blue | Black | White | Silver

Select the color of the vehicle.

Initial position [X, Y, Z] (m) — Initial vehicle position

[0, 0, 0] (default) | real-valued 1-by-3 vector

Initial vehicle position along the X-axis, Y-axis, and Z-axis of the scene. This position is in the inertial Z-up coordinate system. Units are in meters.

Set the X and Y values of this parameter to match the X and Y input port values at the start of simulation.

Initial rotation [Roll, Pitch, Yaw] (deg) — Initial angle of vehicle rotation

[0, 0, 0] (default) | real-valued 1-by-3 vector

Initial angle of vehicle rotation. The angle of rotation is defined by the roll, pitch, and yaw of the vehicle. Units are in degrees.

Set the yaw value of this parameter to match the Yaw input port value at the start of simulation.

Name — Name of vehicle

SimulinkVehicle1 (default) | vehicle name

Name of vehicle. By default, when you use the block in your model, the block sets the Name parameter to SimulinkVehicleX. The value of X depends on the number of Simulation 3D Vehicle with Ground Following blocks that you have in your model.

The vehicle name appears as a selection in the Parent name parameter of any Automated Driving Toolbox™ Simulation 3D sensor blocks within the same model as the vehicle. With the Parent name parameter, you can select the vehicle on which to mount the sensor.

Sample time — Sample time

-1 (default) | positive scalar

Sample time, T_s, in seconds. The graphics frame rate is the inverse of the sample time.

If you set the sample time to -1, the block uses the sample time specified in the Simulation 3D Scene Configuration block.

Light Controls

Enable light controls — Control vehicle lights

off (default) | on

Select whether to control the vehicle headlights. Use the enabled parameters to set the light parameters, including headlight intensity.

Dependencies

Selecting this parameter:

• Creates the input port Light controls

• Enables these light parameters.

  Lights	Light Parameters
  Headlights	Headlight color High beam intensity Low beam intensity High beam cone half angle Low beam cone half angle Left headlight beam orientation Right headlight beam orientation
  Brake lights	Brake light intensity
  Reverse lights	Reverse light intensity
  Turn signal lights	Turn signal light intensity Period Pulse width

Headlights

Headlight color [R,G,B] — Headlight color

[1,1,1] (default) | 1-by-3 array of RGB triplet values

Headlight color, specified as a normalized 1-by-3 array of RGB triplet values.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: int8 | uint8

High beam intensity (cd) — High beam intensity

100000 (default) | positive scalar

High beam intensity, in cd.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Low beam intensity (cd) — Low beam intensity

60000 (default) | positive scalar

Low beam intensity, in cd.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

High beam cone half angle (deg) — High beam cone half angle

70 (default) | positive scalar less than or equal to 90

High beam cone half angle, in deg.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Low beam cone half angle (deg) — Low beam cone half angle

70 (default) | positive scalar less than or equal to 90

Low beam cone half angle, in deg.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Left headlight beam orientation [Pitch, Yaw] (deg) — Left headlight beam orientation [Pitch, Yaw] (deg)

[0,0] (default) | 1-by-2 array with values between -180 and 180

Pitch and yaw orientation of the left headlight beam orientation in the Z-up coordinate system, specified as a 1-by-2 array, in deg. The first element of the array, [1,1], is the pitch angle. The second element of the array, [1,2] is the yaw angle.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Right headlight beam orientation [Pitch, Yaw] (deg) — Right headlight beam orientation

[0,0] (default) | 1-by-2 array with values between -180 and 180

Pitch and yaw orientation of the right headlight beam orientation in the Z-up coordinate system, specified as a 1-by-2 array, in deg. The first element of the array, [1,1], is the pitch angle. The second element of the array, [1,2] is the yaw angle.

Dependencies

To enable this parameter, select Enable light controls.

Brake Lights

Brake light intensity (cd/m^2) — Intensity

500 (default) | positive scalar

Brake light intensity, in cd/m^2.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Reverse Lights

Reverse light intensity (cd/m^2) — Intensity

500 (default) | positive scalar

Reverse light intensity, in cd/m^2.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Turn Signal Lights

Turn signal light intensity (cd/m^2) — Intensity

500 (default) | positive scalar

Turn signal light intensity, in cd/m^2.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Period (s) — Turn signal light period

1 (default) | positive scalar

Turn signal light period, in s.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Pulse width (% of period) — Pulse width

50 (default) | positive scalar less than 100

Turn signal light pulse width, as a percent of the period.

Dependencies

To enable this parameter, select Enable light controls.

Data Types: double

Ground Truth

Output location (m) and orientation (rad) — Output location and orientation of vehicle

off (default) | on

Select this parameter to output the location and orientation of the vehicle at the Location and Orientation ports, respectively.

More About

Import Custom Meshes

To import custom meshes for defining custom vehicles, follow these steps:

1. Install the Automated Driving Toolbox Interface for Unreal Engine Projects support package. See Install Support Package for Customizing Scenes (Automated Driving Toolbox).

2. On the block Parameters tab, set Type to Custom.

3. In the Path to custom mesh field, enter the path to the vehicle mesh in the Unreal Engine project. For example, enter /MathWorksSimulation/Vehicles/Muscle/Meshes/SK_MuscleCar.SK_MuscleCar.

   To create a custom vehicle mesh, see Prepare Custom Vehicle Mesh for the Unreal Editor (Automated Driving Toolbox).

4. Use the vehicle dimensions in the custom mesh to enter the dimensions in the corresponding block parameter fields.

Control Vehicle Lights

To control the lights of vehicles in a scene, follow these steps:

1. Install the Automated Driving Toolbox Interface for Unreal Engine Projects support package. See Install Support Package for Customizing Scenes (Automated Driving Toolbox).

2. On the block Light Controls tab, select Enable light controls.

3. Use the enabled parameters to specify the vehicle light for:

   • Headlights

   • Brake lights

   • Reverse lights

   • Turn signal lights

4. Connect Boolean light control signals to the Signal lights input port.

References

[1] Vehicle Dynamics Standards Committee. Vehicle Dynamics Terminology. SAE J670. Warrendale, PA: Society of Automotive Engineers, 2008.

[2] Technical Committee. Road vehicles — Vehicle dynamics and road-holding ability — Vocabulary. ISO 8855:2011. Geneva, Switzerland: International Organization for Standardization, 2011.

Version History

Introduced in R2024a