'SamplesPerFrame' property does not work in kinematicTrajectory function?

Hi,

I am using Matlab R2019b sensor fusion and tracking toolbox, and got the following warning when I set up the 'SamplePerFrame' property of kinematicTrajectory

> trajectory = kinematicTrajectory('SampleRate', 20, 'SamplesPerFrame', 100)

Warning: The SamplesPerFrame property is not relevant in this configuration of the System object.

> In matlab.system.SystemProp/setProperties

In kinematicTrajectory (line 253)

When I run the following command:

>> bodyAcceleration = [5,5,0]; bodyAngularVelocity = [0,0,1];

>> [position,orientation,velocity,acceleration,angularVelocity] = trajectory(bodyAcceleration,bodyAngularVelocity)

I expected the size of position is 100*3, however I only got a single output, is that related to the warning above?

Thank a lot!

Answer 1

[Sai Sri Pathuri]

If you use 'SamplesPerFrame' property with kinematictrajectory system object, you need to set 'AccelerationSource' and 'AngularVelocitySource' to 'Property'.

trajectory = kinematicTrajectory('SampleRate', 20, 'SamplesPerFrame', 100, 'AccelerationSource', 'Property', 'AngularVelocitySource', 'Property');

Here is the link to documentation mentioning this dependency in SamplesPerFrame property section: https://in.mathworks.com/help/nav/ref/kinematictrajectory-system-object.html#mw_7550710d-cdce-4092-9ffc-efd20e1ef0d8

Since you have declared AccelerationSource and AngularVelocitySource as properties, you may define them using Acceleration and AngularVelocity properties respectively and then use system object as below.

trajectory = kinematicTrajectory('SampleRate', 20, 'SamplesPerFrame', 100, ....
     'AccelerationSource', 'Property', 'AngularVelocitySource', 'Property',...
     'Acceleration', [5,5,0], 'AngularVelocity', [0,0,1]);
[position,orientation,velocity,acceleration,angularVelocity] = trajectory();

[Xiaohui Wang]

Thanks a lot!