Hi Vimal,
The trackerPHD must be constructed with a cell array of trackingSensorConfiguration objects. By setting HasSensorConfigurationsInput to true, you can "update" the configurations of the sensors used by trackerPHD.
The trackingSensorConfiguration object defines both tunable (properties which can be updated) and non-tunable properties of a sensor. The list of "tunable" properties include - "IsValidTime", "SensorLimits", "SensorResolution", "SensorTransformParameters". This list of tunable properties can be passed as an input to the tracker step either as a struct array, a cell array of struct or a cell array of trackingSensorConfiguration objects. Passing cell array of trackingSensorConfiguration objects is a convenience offered by trackerPHD, but only the above-mentioned "tunable" fields are updated.
Now, as you noticed, you cannot pass the cell array of trackingSensorConfiguration to an entry-point function for code generation. Therefore, you must use an array or cell array of struct with the tunable fields as an input to the tracker.
To construct the tracker (inside isempty(tracker)), you can convert this struct array into cell array of trackingSensorConfiguration objects by taking "tunable" fields from the input and adding "non-tunable" fields on top of it.
Shown below is an example entry-point function for trackerPHD which demonstrates this.
function tracks = phdEntryPoint(detections, configurations, time)
% Define tracker as persistent object
persistent tracker
% Define the tracker on the first call
if isempty(tracker)
% Create sensor configurations for constructing a PHD tracker
sensorConfigurations = cell(numel(configurations),1);
for i = 1:numel(sensorConfigurations)
sensorConfigurations{i} = trackingSensorConfiguration(...
'SensorIndex',configurations(i).SensorIndex,...
'IsValidTime',configurations(i).IsValidTime,...
'SensorLimits',configurations(i).SensorLimits,...
'SensorTransformParameters',configurations(i).SensorTransformParameters,...
'SensorResolution',configurations(i).SensorResolution);
% Define the rest of properties, which don't change with time and
% depends on the sensor characteristics. Here you should define
% these values based on the "SensorIndex". For example, if
% SensorIndex = 1 is a Camera and outputs a single detection per
% object. In that case, you can set its MaxNumDetsPerObject = 1.
sensorConfigurations{i}.ClutterDensity = 1e-6;
sensorConfigurations{i}.DetectionProbability = 0.9;
sensorConfigurations{i}.MaxNumDetsPerObject = inf;
end
% Construct the tracker
tracker = trackerPHD(...
'SensorConfigurations',sensorConfigurations,...
'HasSensorConfigurationsInput',true);
end
% Update the tracker every step
tracks = tracker(detections, configurations, time);
end
To generate code from a function like this, you will need to define the data types of all the inputs. This can be achieved by using sample detections from the scenario simulation or you can manually define data types as shown in the below script. After defining the data types of inputs, you can simply use the "codegen" command to generate code.
sampleDetection = objectDetection(0,[0;0;0],...
'MeasurementParameters',measParams());
detections = coder.typeof({sampleDetection},[100 1],[1 0]); % Max detections = 100
sampleConfigurationInput = struct('SensorIndex',1,...
'IsValidTime',false,...
'SensorLimits',zeros(3,2),...
'SensorTransformParameters',configParams(),...
'SensorResolution',zeros(3,1));
configurations = coder.typeof(sampleConfigurationInput,[8 1],[0 0]); % Assume 8 sensors
time = coder.typeof(0);
codegen phdEntryPoint -args {detections, configurations, time}
function st = measParams()
st = repmat(struct('Frame','Rectangular',...
'OriginPosition',zeros(3,1),...
'OriginVelocity',zeros(3,1),...
'Orientation',zeros(3),...
'IsParentToChild',false,...
'HasAzimuth',false,...
'HasElevation',false,...
'HasRange',false,...
'HasVelocity',false),2,1);
end
function st = configParams()
st = repmat(struct('Frame','Spherical',...
'OriginPosition',zeros(3,1),...
'OriginVelocity',zeros(3,1),...
'Orientation',zeros(3),...
'IsParentToChild',false,...
'HasAzimuth',false,...
'HasElevation',false,...
'HasRange',false,...
'HasVelocity',false),2,1);
end
