initekfimm

Initialize trackingIMM object

Since R2018b

Syntax

imm = initekfimm(detection)

Description

imm = initekfimm(detection) initializes a constant velocity (CV), constant acceleration (CA), and a constant turn (CT) trackingIMM (imm) object based on information provided in an objectDetection object, detection.

The function initializes a constant velocity state [x v_x y v_y z v_z].

Examples

Detection with Position Measurement in Rectangular Frame

A 3-D position measurement in rectangular frame is provided. For example, x = 1, y = 3, and z = 0. Use a 3-D position measurement noise [1 0.4 0; 0.4 4 0; 0 0 1].

detection = objectDetection(0, [1;3;0], 'MeasurementNoise', [1 0.4 0; 0.4 4 0; 0 0 1]);

Use initekfimm to create a trackingIMM filter initialized at the provided position and using the measurement noise defined above.

imm = initekfimm(detection);

Check the values of the state and measurement noise. Verify that the filter state, imm.State, has the same position components as detection measurement, detection.Measurement.

imm.State

ans = 6×1

     1
     0
     3
     0
     0
     0

Verify that the filter measurement noise, imm.MeasurementNoise, is the same as the detection.MeasurementNoise values.

imm.MeasurementNoise

ans = 3×3

    1.0000    0.4000         0
    0.4000    4.0000         0
         0         0    1.0000

Detection with Position Measurement in Spherical Frame

A 3-D position measurement in spherical frame is provided. For example: az = 40, el = 6, r = 100, rr = 5. Measurement noise is diag([2.5, 2.5, 0.5, 1].^2).

meas = [40;6;100;5];
measNoise = diag([2.5,2.5,0.5,1].^2);

Use the MeasurementParameters to define the frame. You can leave out other fields of the MeasurementParameters struct, and they will be completed by default values. In this example, sensor position, sensor velocity, orientation, elevation, and range rate flags are default.

measParams = struct('Frame','spherical');
detection = objectDetection(0,meas,'MeasurementNoise',measNoise,...
     'MeasurementParameters', measParams); 

Use initekfimm to create a trackingIMM filter initialized at the provided position and using the measurement noise defined above.

imm = initekfimm(detection)

imm = 
  trackingIMM with properties:

                      State: [6x1 double]
            StateCovariance: [6x6 double]

            TrackingFilters: {3x1 cell}
     HasMeasurementWrapping: [1 1 1]
           MeasurementNoise: [4x4 double]

         ModelConversionFcn: @switchimm
    TransitionProbabilities: [3x3 double]
         ModelProbabilities: [3x1 double]

            MaxNumOOSMSteps: 0

            EnableSmoothing: 0

Input Arguments

detection — Detection report

objectDetection object

Detection report, specified as an objectDetection object.

Example: detection = objectDetection(0,[1;4.5;3],'MeasurementNoise', [1.0 0 0; 0 2.0 0; 0 0 1.5])

Output Arguments

imm — trackingIMM object

trackingIMM object

Constant velocity (CV), constant acceleration (CA), and a constant turn (CT) trackingIMM (imm) object based on information provided in detection, returned as a trackingIMM object.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2018b