Problem with pbvs.run()

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Angelika Peer

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Jul 13, 2020, 4:00:34 AM7/13/20
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Dear all,
I am using Robotics Toolbox for Matlab (version 10), RVC2, and Matlab R2020a. I am writing as I am experiencing problems with the command

pbvs.run();

When I am executing the example contained in the book Robotics, Vision and Control on page 539, section 15.1 as follows:

cam=CentralCamera('default');
P=mkgrid(2,0.5,'pose', SE3(0,0,3));
T_C0=SE3(1,1,-3)*SE3.Rz(0.6);
Cd_T_G=SE3(0,0,1);
pbvs=PBVS(cam, 'pose0', T_C0, 'posef', Cd_T_G, 'axis', [-1 2 -1 2 -3 0.5]);
pbvs.run();

I am getting the following error message:

The class SE3 has no Constant property or Static method named 'check'.

Error in PBVS/init (line 110)
            vs.camera.T = SE3.check(vs.T0);    % set camera back to its initial pose

Error in VisualServo/run (line 122)
            vs.init();

The method 'check' seems to be non-existing.

Any help in resolving this issue would be highly appreciated.

Regards,
Angelika Peer
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Erik van Oene

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Jul 13, 2020, 5:54:52 AM7/13/20
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Hi,

The code works find on my PC.

I'm using:
 - Matlab 2019b
 - Robotics Toolbox for MATLAB (release 10.4)
 - Machine Vision Toolbox for MATLAB (release 3.4)
 - Spatial Math Toolbox for MATLAB (release 1.0)

I would suggest to update the toolbox to the latest version. Problem might be fixed in the Spatial Math Toolbox which contains the SE3 class.

Erik

Op maandag 13 juli 2020 10:00:34 UTC+2 schreef Angelika Peer:

Angelika Peer

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Jul 13, 2020, 9:07:36 AM7/13/20
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I removed the old installation and all set paths and reinstalled things again using the Matlab Drive version under Matlab R2020a. I have now installed (copied from output of startup_rvc.m):

- Robotics Toolbox for MATLAB (release 10.4)
- Machine Vision Toolbox for MATLAB (release 4.3)

- Spatial Math Toolbox for MATLAB (release 1.0)


When I am trying to execute the commands from above, I still get the same error. I also tried to run

which -all SE3

which gives me:

C:\Users\AngPeer\MATLAB Drive\RVC2\rvctools\spatial-math\SE3.m  % SE3 constructor
C:\Users\AngPeer\MATLAB Drive\RVC2\rvctools\spatial-math\SO3.m  % SO3 method

so the path is pointing to the version on the Matlab Drive.

Peter Corke

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Jul 18, 2020, 7:35:19 PM7/18/20
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Hi Angelika,

the useful clue here is that you are using the MATLAB Drive install version.  I don't have an automated update process for that, the best/latest version is what's on GitHub.  That said, I've just updated vision and spatial math folders on Drive to reflect the latest version.

Let me know if there are any issues.  Make sure that you have the MATLAB Drive Connector up and running.

peter

Angelika Peer

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Jul 21, 2020, 7:47:11 AM7/21/20
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Dear Peter,

Thanks a lot for your prompt reply. I waited for Matlab Drive to sync the new version and then tried to run the lines of code below again. Unfortunately, the error is still the same:

 

The class SE3 has no Constant property or Static method named 'check'.

 

Error in PBVS/init (line 110)

            vs.camera.T = SE3.check(vs.T0);    % set camera back to its initial pose

 

Error in VisualServo/run (line 122)

            vs.init();

 

When I check the dates of files in the Matlab Drive folder, several files have a date of 19/07/2020, so the toolbox seems to have been updated. Also the problem I had with the mkgrid command got resolved this way, but apparently, this problem is still there.

 

Regards,

Angelika

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Alex Smith

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Jul 29, 2020, 8:50:23 AM7/29/20
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Hi Angelika, Peter, 

I have also tested using the same setup as Angelika, and got the exact same error. 

I noticed there is a small mistake in the static functions of SE3.m where the "convert" function is documented as "SE3.check" in the % comment section (line 946).

In PBVS.m there are two lines which use SE3.check(vs.T0) (lines 112, 113), maybe these should be SE3.convert instead? 

It seems toolbox files are read only using the MATLAB drive - or I am missing something - but I can't change PBVS.m to test this, maybe someone using the git version can double check this. 

Regards,
Alex

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Mildred Espinosa

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Nov 21, 2021, 3:31:03 AM11/21/21
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Hi Peter:

Same as the others, mkgrid got fixed but no SE(3).
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