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lookupPose

Obtain pose information for certain time

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Syntax

[position,orientation,velocity,acceleration,angularVelocity] = lookupPose(traj,sampleTimes)

Description

[position,orientation,velocity,acceleration,angularVelocity] = lookupPose(traj,sampleTimes) returns the pose information of the waypoint trajectory at the specified sample times. If any sample time is beyond the duration of the trajectory, the corresponding pose information is returned as NaN.

example

Examples

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Open Live Script

Create a waypointTrajectory object that connects two waypoints. The velocity of the trajectory at the two waypoints is 0 m/s and 10 m/s, respectively. Restrict the jerk limit to 0.5 m/s3 to enable the trapezoidal acceleration profile.

waypoints = [0  0  0;
            10 50 10];
speeds = [0 10];
jerkLimit = 0.5;
trajectory = waypointTrajectory(waypoints,GroundSpeed=speeds,JerkLimit=jerkLimit);

Obtain the initial time and final time of the trajectory by querying the TimeOfArrival property. Create time stamps to sample the trajectory.

t0 = trajectory.TimeOfArrival(1);
tf = trajectory.TimeOfArrival(end);
sampleTimes = linspace(t0,tf,100);

Obtain the position, velocity, and acceleration information at these sampled time stamps using the lookupPose object function.

[position,~,velocity,acceleration,~] = lookupPose(trajectory,sampleTimes);

Plot the trajectory.

figure()
plot3(position(:,1),position(:,2),position(:,3))
xlabel("x (m)")
ylabel("y (m)")
zlabel("z (m)")
title("Trajectory")

Figure contains an axes object. The axes object with title Trajectory, xlabel x (m), ylabel y (m) contains an object of type line.

Plot the velocity profile.

figure()
subplot(3,1,1)
plot(sampleTimes,velocity(:,1));
ylabel("v_x (m/s)")
title("Velocity Profile")
subplot(3,1,2)
plot(sampleTimes,velocity(:,2));
ylabel("v_y (m/s)")
subplot(3,1,3)
plot(sampleTimes,velocity(:,3));
ylabel("v_z (m/s)")
xlabel("Time (sec)")

Figure contains 3 axes objects. Axes object 1 with title Velocity Profile, ylabel v_x (m/s) contains an object of type line. Axes object 2 with ylabel v_y (m/s) contains an object of type line. Axes object 3 with xlabel Time (sec), ylabel v_z (m/s) contains an object of type line.

Plot the acceleration profile. From the results, the acceleration profile of the planar motion is trapezoidal.

figure()
subplot(3,1,1)
plot(sampleTimes,acceleration(:,1));
axis padded
ylabel("a_x (m/s^2)")
title("Acceleration Profile")
subplot(3,1,2)
plot(sampleTimes,acceleration(:,2));
ylabel("a_y (m/s^2)")
axis padded
subplot(3,1,3)
plot(sampleTimes,acceleration(:,3));
ylabel("a_z (m/s^2)")
xlabel("Time (sec)")

Figure contains 3 axes objects. Axes object 1 with title Acceleration Profile, ylabel a_x (m/s^2) contains an object of type line. Axes object 2 with ylabel a_y (m/s^2) contains an object of type line. Axes object 3 with xlabel Time (sec), ylabel a_z (m/s^2) contains an object of type line.

Input Arguments

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Waypoint trajectory, specified as a waypointTrajectory object.

Sample times in seconds, specified as an M-element vector of nonnegative scalars.

Output Arguments

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Position in the local navigation coordinate system in meters, returned as an M-by-3 matrix.

M is specified by the sampleTimes input.

Data Types: double

Orientation in the local navigation coordinate system, returned as an M-by-1 quaternion column vector or a 3-by-3-by-M real array.

Each quaternion or 3-by-3 rotation matrix is a frame rotation from the local navigation coordinate system to the current body coordinate system.

M is specified by the sampleTimes input.

Data Types: double

Velocity in the local navigation coordinate system in meters per second, returned as an M-by-3 matrix.

M is specified by the sampleTimes input.

Data Types: double

Acceleration in the local navigation coordinate system in meters per second squared, returned as an M-by-3 matrix.

M is specified by the sampleTimes input.

Data Types: double

Angular velocity in the local navigation coordinate system in radians per second, returned as an M-by-3 matrix.

M is specified by the sampleTimes input.

Data Types: double

Version History

Introduced in R2018b

See Also

Objects

Functions