## Folder including the 3D positions (x, y, z) of the rigid body center is empty.

tuelin
Posts: 3
Joined: Tue Sep 03, 2019 3:43 am

### Folder including the 3D positions (x, y, z) of the rigid body center is empty.

Hello,

we are tracking the end effector position of a robot. Therefore we attached a rigid body to the end effector. The robots end effector moves for example from an angle [0, 0, -90] to the angle [0, 0, +90]. Every step it moves 10 degrees further: [0, 0, -90] --> [0, 0, -80] --> [0, 0, -70] until it reached [0, 0, +90]. At every step motive sends the 3D Position (x, y, z) of the rigid body center to matlab.

Now we should have the 3D Position in matlab for every step:

file1: 3D Position [0, 0, -90]
file2: 3D Position [0, 0, -80]
.
.
.
file19: 3D Position [0, 0, +90]

However the problem is some files are just empty, although it should include the 3D position of the rigid body center.

Does anyone has any idea what might be the reason for this problem?

tuelin
Posts: 3
Joined: Tue Sep 03, 2019 3:43 am

### Re: Folder including the 3D positions (x, y, z) of the rigid body center is empty.

I started a few more experiments and during the runtime of the experiments I could observe the following:

(as I stated in my post before, we are tracking the end effector position of a robot. The 3D Position is captured through the cameras and is send from Motive to matlab)

However we get an empty array at random targets instead of an array with the 3D position.
Target1/Position1: x, y, z
x, y, z
x, y, z
...
Target2/Position2: x, y, z
x, y, z
x, y, z
...

Target3/Position3: [ ]

Target4/Position4: x, y, z
x, y, z
x, y, z
...

Target5/Position5: [ ]

Target6/Position6: x, y, z
x, y, z
x, y, z
...

At Target4 and Target6 matlab generates the following error message (basically first the error occurs at Target3 for example and at next Target the error message is shown):

Starting Mocap data recording...
Error while evaluation TimerFcn for timer 'timer-1'

Attempting to access the property or method of an invalid object.
Stopping Mocap data recording...