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Create constant velocity tracking alpha-beta filter from detection report



abf = initcvabf(detection) initializes a constant velocity alpha-beta filter for object tracking based on information provided in detection.

The function initializes a constant velocity state with the same convention as constvel and cvmeas, [x; vx; y; vy; z; vz].


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Create an objectDetection with a position measurement at x=1, y=3 and a measurement noise of [1 0.2; 0.2 2];

detection = objectDetection(0,[1;3],'MeasurementNoise',[1 0.2;0.2 2]);

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

ABF = initcvabf(detection);

Check the values of the state and measurement noise. Verify that the filter state, ABF.State, has the same position components as the Detection.Measurement. Verify that the filter measurement noise, ABF.MeasurementNoise, is the same as the Detection.MeasurementNoise values.

ans = 4×1


ans = 2×2

    1.0000    0.2000
    0.2000    2.0000

Input Arguments

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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

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Constant velocity alpha-beta tracking filter for object tracking, returned as a trackingABF object.


  • The function computes the process noise matrix assuming a unit acceleration standard deviation.

  • You can use this function as the FilterInitializationFcn property of trackers.

Extended Capabilities

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

Introduced in R2018b