error using forward kinematics function (fkine)

[mustafa jaber]

Dear All,

I'm building a model and a simulation of a SCARA robot using MATLAB,
and I've found this amazing toolbox but I have a problem using fkine,
it gives me an error. this is the code I write to build the model.

L1=link([pi 1 0 0 0])
L2=link([pi 1 0 0 0])
L3=link([pi 0 1 0 pi])
L4=link([pi 0 0 0 0])

rclass=robot({L1 L2 L3 L4})

t=[0:.1:10];
Qa=[0;pi/4];
Qb=[pi;pi/2];

[Q QD QDD]=jtraj(Qa,Qb,t);

TJ=fkine(rclass, Q)

when I execute the last line, it gives me the following error,

??? Error using ==> fkine at 60
bad data

can anyone please tell me what is the problem in it?!!!


thank you

[Peter Corke]

Joint coordinates must be row vectors. For a trajectory there is one row per timestep.

Probably I should fix that error message...

peter.

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[Renu Gupta]

Q is a row matrix which you need to define...I too encountered the
same problem...I defined Q and my problem was solved...My code is
l1=link([-pi/2 0 1 0]);
l2=link([0 2 0 -pi/2]);
l3=link([0 2 0 0]);
l4=link([-pi/2 0 0 0]);
l5=link([0 0 1 0]);
test= robot({l1 l2 l3 l4 l5});
drivebot(test);
q=[0 0 0 0 0];
tj=fkine(test,q);
display(tj);

[Peter Corke]

Guys,

you are using commands for version 8 (or older) of RTB with version 9 of the software.  Where do you get the example commands from?

peter

On 07/09/2012, at 5:55 PM, ankur agrawal wrote:

 L1 = link([0 1 0 0],'standard')

L2 = link([0 1 0 0],'standard')

L3 = link([0 1 0 0],'standard')

r = robot({L1,L2,L3})

plot(r,[1,1,1]);

Cannot find an exact (case-sensitive) match for 'link'

The closest match is: Link

in C:\Documents and Settings\Home\My

Documents\MATLAB\robot-9.6\rvctools\robot\Octave\@Link\Link.m

i got this error can anyone help pls...urgent need

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