Get branch history of maintained tracks
history = getHistory(branchHistoryMgr)trackBranchHistory
System object™, branchHistoryMgr.
history = getHistory(branchHistoryMgr,format)'table' or
'matrix'.
Apply the results of an assignment algorithm to a track-oriented, multi-hypothesis tracking (MHT) branch history manager. View the resulting track branches (hypotheses).
Create the MHT branch history manager, which is a trackBranchHistory System object™. Set the object to maintain a history of four sensors and two scans.
branchHistoryMgr = trackBranchHistory('MaxNumSensors',4,'MaxNumHistoryScans',2)
branchHistoryMgr =
trackBranchHistory with properties:
MaxNumSensors: 4
MaxNumHistoryScans: 2
MaxNumTracks: 200
MaxNumTrackBranches: 3
Update the branch history. Because the first update has no previous branches, the branch history manager contains only unassigned detections.
emptyAssignment = zeros(0,2,'uint32'); emptyUnassignment = zeros(0,1,'uint32'); unassignedDetections = uint32([1;2;3]); originatingSensor = [1 1 2]; history = branchHistoryMgr(emptyAssignment,emptyUnassignment, ... unassignedDetections,originatingSensor);
View the current branch history by using the getHistory function. Each detection is assigned to a separate track.
getHistory(branchHistoryMgr)
ans=3×5 table
TrackID ParentID BranchID Scan2 Scan1
Sensor1 Sensor2 Sensor3 Sensor4 Sensor1 Sensor2 Sensor3 Sensor4
_______ ________ ________ ________________________________________ ________________________________________
1 0 1 1 0 0 0 0 0 0 0
2 0 2 2 0 0 0 0 0 0 0
3 0 3 0 3 0 0 0 0 0 0
Specify multiple branch assignments and multiple unassigned track branches and detections.
Assign branch 1 to detections 1 and 2.
Assign branch 2 to detections 1 and 2.
Consider track branches 1 and 3 unassigned.
Consider detections 1, 2, and 3 unassigned.
assignments = uint32([1 1; 1 2; 2 1; 2 2]); unassignedTracks = uint32([1;3]); unassignedDetections = uint32([1;2;3]);
Update the branch history manager with the assignments and unassigned tracks and detections.
history = branchHistoryMgr(assignments,unassignedTracks, ...
unassignedDetections,originatingSensor);View the updated branch history.
getHistory(branchHistoryMgr)
ans=9×5 table
TrackID ParentID BranchID Scan2 Scan1
Sensor1 Sensor2 Sensor3 Sensor4 Sensor1 Sensor2 Sensor3 Sensor4
_______ ________ ________ ________________________________________ ________________________________________
1 1 1 0 0 0 0 1 0 0 0
3 3 3 0 0 0 0 0 3 0 0
4 0 4 1 0 0 0 0 0 0 0
5 0 5 2 0 0 0 0 0 0 0
6 0 6 0 3 0 0 0 0 0 0
1 1 7 1 0 0 0 1 0 0 0
1 1 8 2 0 0 0 1 0 0 0
2 2 9 1 0 0 0 2 0 0 0
2 2 10 2 0 0 0 2 0 0 0
Inspect the branch history.
The most recent scan is Scan 2. The previous scan is Scan 1, which was Scan 2 in the previous assignment update. The history has shifted one scan to the right.
Branches 1 and 3 are the branches for the unassigned tracks.
Branch 2 is no longer in the history because it was not considered to be unassigned. Its assignment to detections 1 and 2 created branches 9 and 10.
Branches 4–6 are branches created for the unassigned detections.
Branches 7–10 are branches created for the track assignments.
branchHistoryMgr — Input branch history managertrackBranchHistory
System objectInput branch history manager, specified as a trackBranchHistory
System object.
format — Format of output branch history'table'
(default) | 'matrix'Format of the output branch history, specified as one of the following:
'table' (default) — Return branch history in a table.
'matrix' — Return branch history in a matrix. This output is
equivalent to the output returned when calling the trackBranchHistory
System object.
history — Branch historyBranch history, returned as a table of integers or as a matrix of integers.
Each row of history represents a unique
track branch. history has 3+(D×S)
columns, where D is the number of maintained scans (the history depth) and
S is the maximum number of maintained sensors. The first three columns
represent the following information about each track branch:
TrackID — ID of the track that is associated with the branch.
Track branches that are assumed to have originated from the same target have the
same track ID. If a branch originates from an unassigned detection, that branch gets
a new track ID.
ParentID — ID of the parent branch, that is, the branch from
which the current branch originated. Branches that were created from the same parent
have the same ParentID. A ParentID of 0
indicates a new track. These tracks are created from hypotheses corresponding to
unassigned detections.
BranchID — Unique ID of track branch. Every branch created from
an unassigned detection or assignment gets a new branch ID.
The remaining D×S columns
contain the IDs of the detections assigned to each branch. A branch can be assigned to at most
one detection per scan and per sensor. The table shows the organization of these columns with
sample detections. N is the number of scans. A value of 0
means that the sensor at that scan does not have a detection assigned to it.
| Scan N | Scan N – 1 | . . . | Scan N – D | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sensor – 1 | Sensor – 2 | . . . | Sensor – S | Sensor – 1 | Sensor – 2 | . . . | Sensor – S | . . . | Sensor – 1 | Sensor – 2 | . . . | Sensor – S |
|
| ... |
|
|
| ... |
| ... |
|
| ... |
|
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