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objectDetection

Report for single object detection

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Description

AnobjectDetectionobject contains an object detection report that was obtained by a sensor for a single object. You can use theobjectDetectionoutput as the input to trackers.

Creation

Syntax

detection = objectDetection(time,measurement)
detection = objectDetection(___,Name,Value)

Description

example

detection= objectDetection(time,measurement)creates an objectdetectionat the specifiedtimefrom the specifiedmeasurement.

example

detection= objectDetection(___,Name,Value)creates adetectionobject with properties specified as one or moreName,Valuepair arguments. Any unspecified properties have default values. You cannot specify theTimeorMeasurementproperties usingName,Valuepairs.

Input Arguments

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Detection time, specified as a nonnegative real scalar. This argument sets theTimeproperty.

Object measurement, specified as a real-valuedN-element vector.N是determined by the coordinate system used to report detections and other parameters that you specify in theMeasurementParametersproperty for theobjectDetectionobject.

This argument sets theMeasurementproperty.

Output Arguments

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Detection report for a single object, returned as anobjectDetectionobject. AnobjectDetectionobject contains these properties:

Property Definition
Time Measurement time
Measurement Object measurements
MeasurementNoise Measurement noise covariance matrix
SensorIndex Unique ID of the sensor
ObjectClassID Object classification
ObjectAttributes Additional information passed to tracker
MeasurementParameters Parameters used by initialization functions of nonlinear Kalman tracking filters

Properties

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Detection time, specified as a nonnegative real scalar. You cannot set this property as a name-value pair. Use thetimeinput argument instead.

Example:5.0

Data Types:double

Object measurement, specified as a real-valuedN-element vector. You cannot set this property as a name-value pair. Use themeasurementinput argument instead.

Example:[1.0;-3.4]

Data Types:double|single

Measurement noise covariance, specified as a scalar or a real positive semi-definite symmetricN-by-Nmatrix.N是the number of elements in the measurement vector. For the scalar case, the matrix is a square diagonalN-by-Nmatrix having the same data interpretation as the measurement.

Example:[5.0,1.0;1.0,10.0]

Data Types:double|single

Sensor identifier, specified as a positive integer. The sensor identifier lets you distinguish between different sensors and must be unique to the sensor.

Example:5

Data Types:double

Object class identifier, specified as a positive integer. Object class identifiers distinguish between different kinds of objects. The value0denotes an unknown object type. If the class identifier is nonzero, the trackers immediately create a confirmed track from the detection.

Example:1

Data Types:double

Measurement function parameters, specified as a structure array, a cell containing a structure array, or a cell array. The property contains all the arguments used by the measurement function specified by theMeasurementFcnproperty of a nonlinear tracking filter such astrackingEKFortrackingUKF.

The table shows sample fields for theMeasurementParametersstructures.

Field Description Example
Frame

Frame used to report measurements, specified as one of these values:

  • 'rectangular'— Detections are reported in rectangular coordinates.

  • 'spherical'— Detections are reported in spherical coordinates.

 'spherical'
OriginPosition Position offset of the origin of the frame relative to the parent frame, specified as an[x y z]real-valued vector. [0 0 0]
OriginVelocity Velocity offset of the origin of the frame relative to the parent frame, specified as a[vx vy vz]real-valued vector. [0 0 0]
Orientation Frame rotation matrix, specified as a 3-by-3 real-valued orthonormal matrix. [1 0 0; 0 1 0; 0 0 1]
HasAzimuth Logical scalar indicating if azimuth is included in the measurement. 1
HasElevation Logical scalar indicating if elevation is included in the measurement. For measurements reported in a rectangular frame, and ifHasElevation是false, the reported measurements assume 0 degrees of elevation. 1
HasRange Logical scalar indicating if range is included in the measurement. 1
HasVelocity Logical scalar indicating if the reported detections include velocity measurements. For measurements reported in the rectangular frame, ifHasVelocity是false, the measurements are reported as[x y z]. IfHasVelocity是true, measurements are reported as[x y z vx v vz]. 1
IsParentToChild Logical scalar indicating ifOrientationperforms a frame rotation from the parent coordinate frame to the child coordinate frame. WhenIsParentToChild是false, thenOrientationperforms a frame rotation from the child coordinate frame to the parent coordinate frame. 0

Object attributes passed through the tracker, specified as a cell array. These attributes are added to the output of the trackers but not used by the trackers.

Example:{[10,20,50,100],'radar1'}

Examples

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Open Live Script

Create a detection from a position measurement. The detection is made at a timestamp of one second from a position measurement of[100;250;10]in Cartesian coordinates.

detection = objectDetection(1,[100;250;10])
detection = objectDetection with properties: Time: 1 Measurement: [3x1 double] MeasurementNoise: [3x3 double] SensorIndex: 1 ObjectClassID: 0 MeasurementParameters: {} ObjectAttributes: {}
Open Live Script

Create anobjectDetectionfrom a time and position measurement. The detection is made at a time of one second for an object position measurement of[100;250;10]. Add measurement noise and set other properties using Name-Value pairs.

detection = objectDetection(1,[100;250;10],'MeasurementNoise',10,...'SensorIndex',1,'ObjectAttributes',{'Example object',5})
detection = objectDetection with properties: Time: 1 Measurement: [3x1 double] MeasurementNoise: [3x3 double] SensorIndex: 1 ObjectClassID: 0 MeasurementParameters: {} ObjectAttributes: {'Example object' [5]}

Extended Capabilities

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

版本历史

Introduced in R2018b

See Also

Objects