formationInfo

UAV formation graph and inter-UAV distance

Since R2024b

Syntax

info = formationInfo(trajectoryEnsemble)

Description

info = formationInfo(trajectoryEnsemble) returns a timetable of inter-UAV distance, formation graph, and positions of a UAV trajectory ensemble object.

Examples

Visualize and Obtain Performance Metrics of UAV Formation

Specify the number of UAVs in a UAV formation, and create the timestamps for the UAV trajectories.

% Number of UAVs in the formation
numUAV = 4;

% Timestamps
time = [0; 1];

Specify the position of each UAV in ENU frame in meters at 0 and 1 seconds

uav1_position = [1 0 10;
                1 0 10.5];
uav2_position = [0.5 0.8 10;
                0.5 1.8 11];
uav3_position = [1.5 1 10;
                1.5 1.8 11];
uav4_position = [2 0 10;
                1.5 0 10.5];

Specify the velocity of each UAV in ENU frame in m/s at 0 and 1 seconds

uav1_velocity = [0 0 0.5; 
                1 0 0];
uav2_velocity = [0 1 1;
                1 0 0];
uav3_velocity = [0 1 1;
                1 0 0];
uav4_velocity = [0 0 0.5;
                1 0 0];

Store the trajectory of each UAV in a timetable, and store the timetables in a cell array.

trajData1=timetable(seconds(time),uav1_position,uav1_velocity,VariableNames={'Position','Velocity'});
trajData2=timetable(seconds(time),uav2_position,uav2_velocity,VariableNames={'Position','Velocity'});
trajData3=timetable(seconds(time),uav3_position,uav3_velocity,VariableNames={'Position','Velocity'});
trajData4=timetable(seconds(time),uav4_position,uav4_velocity,VariableNames={'Position','Velocity'});

Create a UAV trajectory ensemble object. Specify the safety radius as 0.25 meters, a maximum connectivity range of 1.5 meters, and a maximum number of neighbors of 5.

trajectoryEnsemble = uavFormationMetrics({trajData1,trajData2,trajData3,trajData4},SafetyRadius=0.25,ConnectivityRange=1.5,...
    MaxNumNeighbors=5);

Obtain the perfomance and distance metrics of the UAV formation.

[perfMetrics,distMetrics] = metrics(trajectoryEnsemble);

Plot the formation performance metrics

stackedplot(perfMetrics)
grid on
title("Formation Performance Metrics")

Plot the distance performance metrics

stackedplot(distMetrics)
grid on
title("Distance Metrics")

Obtain the UAV formation information.

info = formationInfo(trajectoryEnsemble);

Plot the UAV formation at the initial time step

% Create edge label for UAV distance at 0 seconds
edgeLabel0 = info.FormationGraph{1}.Edges.Weight;

% Plot the formation at 0 seconds
plot(info.FormationGraph{1},EdgeLabel=edgeLabel0, ...
    XData=info.PositionX(1,:),YData=info.PositionY(1,:), ...
    ZData=info.PositionZ(1,:));

% Add title labels to each axis
title("UAV Formation at t = 0 seconds")
xlabel("East")
ylabel("North")
zlabel("Up")

Plot the UAV formation after movement at t = 1 second. In this time, some UAVs are out of the connectivity range and form 2 connected subgroups.

% Create edge label for UAV distance at 1 second
edgeLabel1 = info.FormationGraph{2}.Edges.Weight;

% Plot the formation at 1 second
plot(info.FormationGraph{2},EdgeLabel=edgeLabel1, ...
    XData=info.PositionX(2,:),YData=info.PositionY(1,:), ...
    ZData=info.PositionZ(2,:)); 

% Add labels to each axis
title("UAV Formation at t = 1 second")
xlabel("East")
ylabel("North")
zlabel("Up")

Obtain the inter-UAV distance for all UAV pairs in the formation at t = 1 second.

info.InterUAVDistance{2}

ans=6×2 table
    UAVPair    Distance
    _______    ________

    1    2      1.9339 
    1    3      1.9339 
    1    4         0.5 
    2    3           1 
    2    4       2.119 
    3    4      1.8682 

Input Arguments

trajectoryEnsemble — UAV trajectory ensemble

uavFormationMetrics object

UAV trajectory ensemble, specified as a uavFormationMetrics object.

Output Arguments

info — Details of UAV trajectory ensemble object

timetable

Details of UAV trajectory ensemble object, returned as a timetable. Each row of the timetable contains the following variables:

• InterUAVDistance — Distance between UAVs in meters, returned as a M-by-2 table, where M represents the total number of combinations of 2 UAVs that can be formed from all N UAVs in the formation, given by :

  $$M=\frac{N!}{2!\left(N-2\right)!}$$

• FormationGraph — Directed graph of UAV formation, returned as a digraph object.

  In the directed graph, each directed edge represents a connection between pairs of UAVs, with the arrow starting from one UAV and pointing towards its neighboring UAV.

• PositionX — X position of all N UAV in the formation in meters, returned as N element array of real number

• PositionY — Y position of all N UAV in the formation in meters, returned as N element array of real number

• PositionZ — Z position of all N UAV in the formation in meters, returned as N element array of real number

Version History

Introduced in R2024b