getTrackPositions
Returns updated track positions and position covariance matrix
Syntax
Description
returns a matrix of track positions. Each row contains the position of a tracked
object.position
= getTrackPositions(tracks
,positionSelector
)
[
returns a matrix of track positions.position
,positionCovariances
]
= getTrackPositions(tracks
,positionSelector
)
Examples
Find Position of 3-D Constant-Acceleration Object
Create an extended Kalman filter tracker for 3-D constant-acceleration motion.
tracker = trackerTOMHT('FilterInitializationFcn',@initcaekf);
Update the tracker with a single detection and get the tracks output.
detection = objectDetection(0,[10;-20;4],'ObjectClassID',3);
tracks = tracker(detection,0)
tracks = objectTrack with properties: TrackID: 1 BranchID: 1 SourceIndex: 0 UpdateTime: 0 Age: 1 State: [9x1 double] StateCovariance: [9x9 double] StateParameters: [1x1 struct] ObjectClassID: 3 TrackLogic: 'Score' TrackLogicState: [13.7102 13.7102] IsConfirmed: 1 IsCoasted: 0 IsSelfReported: 1 ObjectAttributes: [1x1 struct]
Obtain the position vector from the track state.
positionSelector = [1 0 0 0 0 0 0 0 0; 0 0 0 1 0 0 0 0 0; 0 0 0 0 0 0 1 0 0]; position = getTrackPositions(tracks, positionSelector)
position = 1×3
10.0000 -20.0000 4.0000
Find Position and Covariance of 3-D Constant-Velocity Object
Create an extended Kalman filter tracker for 3-D constant-velocity motion.
tracker = trackerTOMHT('FilterInitializationFcn',@initcvekf);
Update the tracker with a single detection and get the tracks output.
detection = objectDetection(0,[10;3;-7],'ObjectClassID',3);
tracks = tracker(detection,0)
tracks = objectTrack with properties: TrackID: 1 BranchID: 1 SourceIndex: 0 UpdateTime: 0 Age: 1 State: [6x1 double] StateCovariance: [6x6 double] StateParameters: [1x1 struct] ObjectClassID: 3 TrackLogic: 'Score' TrackLogicState: [13.7102 13.7102] IsConfirmed: 1 IsCoasted: 0 IsSelfReported: 1 ObjectAttributes: [1x1 struct]
Obtain the position vector and position covariance for that track
positionSelector = [1 0 0 0 0 0; 0 0 1 0 0 0; 0 0 0 0 1 0]; [position,positionCovariance] = getTrackPositions(tracks,positionSelector)
position = 1×3
10.0000 3.0000 -7.0000
positionCovariance = 3×3
1.0000 -0.0000 0
-0.0000 1.0000 -0.0000
0 -0.0000 1.0000
Input Arguments
tracks
— Object tracks
array of objectTrack
objects | array of structures
Object tracks, specified as an array of objectTrack
objects or an
array of structures containing sufficient information to obtain the track
position information. At a minimum, these structures must contain a
State
column vector field and a positive-definite
StateCovariance
matrix field. For a sample
track structure, see toStruct
.
positionSelector
— Position selection matrix
D-by-N real-valued matrix.
Position selector, specified as a D-by-N real-valued matrix of ones and zeros. D is the number of dimensions of the tracker. N is the size of the state vector. Using this matrix, the function extracts track positions from the state vector. Multiply the state vector by position selector matrix returns positions. The same selector is applied to all object tracks.
Output Arguments
position
— Positions of tracked objects
real-valued M-by-D matrix
Positions of tracked objects at last update time, returned as a real-valued M-by-D matrix. D represents the number of position elements. M represents the number of tracks.
positionCovariances
— Position covariance matrices of tracked objects
real-valued
D-by-D-M
array
Position covariance matrices of tracked objects, returned as a real-valued D-by-D-M array. D represents the number of position elements. M represents the number of tracks. Each D-by-D submatrix is a position covariance matrix for a track.
More About
Position Selector for 2-Dimensional Motion
Show the position selection matrix for two-dimensional motion when the state consists of the position and velocity.
Position Selector for 3-Dimensional Motion
Show the position selection matrix for three-dimensional motion when the state consists of the position and velocity.
Position Selector for 3-Dimensional Motion with Acceleration
Show the position selection matrix for three-dimensional motion when the state consists of the position, velocity, and acceleration.
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Version History
Ouvrir l'exemple
Vous possédez une version modifiée de cet exemple. Souhaitez-vous ouvrir cet exemple avec vos modifications ?
Commande MATLAB
Vous avez cliqué sur un lien qui correspond à cette commande MATLAB :
Pour exécuter la commande, saisissez-la dans la fenêtre de commande de MATLAB. Les navigateurs web ne supportent pas les commandes MATLAB.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)