HighwayCar

Target specification for car driving on highway

Since R2024b

Description

A HighwayCar object contains the target specification for a car driving on the highway. You can use the HighwayCar object as an input to multiSensorTargetTracker. The target specification defines the state convention for trackers initialized with it. For HighwayCar, the output state convention is: [x;y;speed;theta;omega;z;vz;length;width;height], where:

• x, y, and z represent the x-, y, and z-coordinates of the center of the bounding box in meters.

• speed represents the velocity magnitude in meters/second.

• theta represents the course direction in the xy-plane, counter-clockwise with respect to the x-axis, in degrees.

• omega represents the turn-rate in degrees/second.

• vz represents velocity component in the vertical plane in meters/second.

• length, width, and height represent the bounding box dimensions in meters.

Creation

To create a HighwayCar object, use the trackerTargetSpec function with the "automotive", "car", and "highway-driving" input arguments. For example:

spec = trackerTargetSpec("automotive","car","highway-driving")

Properties

ReferenceFrame — Reference coordinate frame

"ego" (default) | "global"

Reference coordinate frame, specified as "ego" or "global".

When you specify this property as

"ego" — The origin of the coordinate system is fixed to an ego vehicle, and the position and orientation of the target are modeled with respect to this ego vehicle. To account for a moving ego vehicle, ego motion compensation is used. This ego motion information must be provided as an input to the tracker initialized with the HighwayCar object. See the More About section for more information on the ego motion data format.

"global" — The origin of the coordinate system is fixed to a stationary global reference frame, and the position and orientation of the target is modeled with respect to this stationary frame. See the dataFormat function for information on how to provide ego pose.

Tip

Choose "global" reference frame if either of the following is true.

• All sensors are mounted on the same ego vehicle, and you know the position and orientation of that ego vehicle in some global reference frame. Additionally, you want the tracks described in that same global reference frame.

• Sensors are mounted on different ego vehicles, which can be either stationary or moving.

You may need to change the YawLimits property of your target specification to account for the yaw of the vehicle in global reference frame. For example,

targetSpec.YawLimits = egoYaw + [-10 10];

Note

You must use the same ReferenceFrame on each target specification and sensor specification to initialize a tracker.

Example: "global"

Data Types: char | string

MaxSpeed — Maximum longitudinal speed

50 (default) | positive scalar

Maximum longitudinal speed of the target, specified as a positive scalar. Units are in meters per second.

Example: 45

Data Types: single | double

MaxAcceleration — Maximum longitudinal acceleration

4 (default) | positive scalar

Maximum longitudinal acceleration of the target, specified as a positive scalar. Units are in meters per second squared.

Example: 2.5

Data Types: single | double

MaxYawRate — Maximum yaw rate

5 (default) | positive scalar

Maximum yaw rate of the target, specified as a positive scalar. This value refers to the fastest rate at which the vehicle can change its direction. Units are in degrees per second.

Example: 3.5

Data Types: single | double

MaxYawAcceleration — Maximum yaw acceleration

20 (default) | positive scalar

Maximum yaw acceleration of the target, specified as a positive scalar. This value refers to the highest rate of change of the yaw rate, indicating how quickly the vehicle can initiate or alter its turning motion. Units are in degrees per second squared.

Example: 15

Data Types: single | double

LengthLimits — Minimum and maximum lengths

[3.6 5.6] (default) | positive scalar

Minimum and maximum lengths of the target, specified as a positive scalar. Units are in meters.

Example: [2.5 5.8]

WidthLimits — Minimum and maximum widths

[1.7 2] | positive scalar

Minimum and maximum widths of the target, specified as a positive scalar. Units are in meters.

Example: [1.6 2.2]

Data Types: single | double

HeightLimits — Minimum and maximum heights

[1.4 2] | positive scalar

Minimum and maximum heights of the target, specified as a positive scalar. Units are in meters.

Example: [1.5 2.1]

Data Types: single | double

Object Functions

dataFormat	Structure for data format required by task-oriented tracker
hasTrackerInput	Determine whether tracker needs additional input for target specification

More About

Data Format Required By Task-Oriented Tracker

After you initialize a tracker using this object and set the ReferenceFrame property to "ego", you need additional ego motion information as input to update the tracker for ego compensation. For a full list of ego motion information required as an input to trackers and their description, see the table below.

Field Name	Description
Time	Timestamps at which ego motion is provided, specified as an N-element array.
EgoPositionalDisplacement	Positional displacement of the ego vehicle at the reported timestamps, specified as an N-by-3 matrix. Each row represents the [dX dY dZ] values for the corresponding timestep. Units are in meters.
EgoRotationalDisplacement	Rotational displacement of the ego vehicle at the reported timestamps, specified as an N-by-3 matrix. Each row represents the [dYaw dPitch dRoll] values for the corresponding timestep. Units are in degrees.

See the dataFormat function for information on how to provide ego motion to the tracker.

Version History

Introduced in R2024b