MATLAB Answers

how to display the end-effector position?

44 views (last 30 days)
Cheng Yoong
Cheng Yoong on 21 May 2011
I have a 3 links robot GUI software. The file can be downloaded through this link:
I use the following command as callback for the textbox for x,y,z position:
set(handles.fromDHandTheta,'String',point4.x) but it doesn't work.
Anyone can help me with that?
Thanks in advance.


jiro on 22 May 2011
Try putting a breakpoint on the line you mentioned, and see what the value for point4.x
Also, check to see if handles.fromDHandTheta is a valid handle:
Cheng Yoong
Cheng Yoong on 24 May 2011
Hi Jiro,
What you mean by putting a breakpoint?
Walter Roberson
Walter Roberson on 24 May 2011
click on the dot that appears to the left of the line number of the line you want to stop at. Then run the program. It will stop executing when you reach that line, and you will be able to examine the state of the variables.

Sign in to comment.

Answers (1)

Ben Mitch
Ben Mitch on 22 May 2011
Hi Cheng
If you're going to post code, I think you'll have to trim it down to the essentials if you want anyone to look at it.
Perhaps you need this?
set(handles.fromDHandTheta, 'String', num2str(point4.x))


Show 2 older comments
Ben Mitch
Ben Mitch on 25 May 2011
Sorry didn't mean that to sound rude, obviously hadn't had my coffee yet. Happy to help, but need more information :).
Cheng Yoong
Cheng Yoong on 27 May 2011
Thanks Ben, my problem solved, I just place the right code at the wrong place. =)
Anyway, do u familiar with robotic stuff?My final year project is about create this robot GUI software and simulate the motion of robot in virtual space. I would like to refine my robot drawing but I have limited knowledge on Matlab Graphic.
Ben Mitch
Ben Mitch on 27 May 2011
Do you mean simulate or < visualize>? In either case, the key feature is geometry. I recommend you start with "homogeneous coordinates", as the guys in 3D graphics do. Then you've got points (4x1 vectors) and transforms (4x4 matrices, like rotations or translations). Build a model of your robot out of points (think, solid parts) and transforms (think, joints with angles that vary over time). Build faces out of points, build solid parts out of faces. Try "doc patch" to get started with visualizing faces. Change the renderer to "OpenGL", YMMV. If you get stuck, post a specific question as a new thread. Good luck.
Of course, there may be tools for robot visualization so you don't have to build everything yourself. Simscape? Have a Google on matlab robot visualization.

Sign in to comment.


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by