How to draw 2 links robot

I have a simple 2 links robot. I have determine the DH parameters and derived the T matrices as shown below: http://www.freeimagehosting.net/uploads/7151d1e0fb.jpg How can I use this derived formula to plot the robot in matlab?

[Jan]

Instead of letting the readers follow the link, you could simply write the small matrix in text format inside your question.

What are "DH" and "T" exactly? In the formula shown in the image there are variables like "c12", "a1" etc. Guessing is not a safe method to answer a question.

Do you have the VirtaulReality toolbox? What does "plot the robot" mean exactly? A 2D diagram of the trajectories or a 3D animation? A phase-plot, which includes the impuls also? Or do you want to plot the formula using LaTeX formatting???

[Cheng Yoong]

I just want to draw a 2D robot,which something similar like this:

http://www.youtube.com/watch?v=tRf39iOaLVc&feature=related

DH stands for Denevit-Hartenberg notation.It is one of the method to describe motion of robot.

T matrices is translational matrices which contain DH parameters.

[Jan]

What have you done so far and where did the problems occur? Do you have the numerical values already or just the formula? Are they available as matrix, or do you want to display the animation online during the simulation?

Please submit all information needed to help you to solve your problem.

[Cheng Yoong]

actually the picture attached is in matrix form. Is it possible to draw something by using matrices?

I just want to draw the robot,probably just 2 links,there is no need to involve animation at the time.

[Jan]

The picture is a matrix, but it contains names of variables and it is not a Matlab matrix. It is impossible to display anything using "a1" and "c12", but you need the numeric values. Before we can suggest any method to draw, we need to know, how these data are represented in Matlab. If I wildly guess these details, the not matching answer is worse than no answer.

Did you look in the example solutions I've posted?

[Cheng Yoong]

yup,i read most of the example,but those codes are too tough for me, cause i'm new in matlab.those "a1" and "c12" are shortforms. For example,c12 represent cos(theta1 + theta2). theta is the angle of link.Will it help in drawing?

[reyam ahmed]

@ Cheng Yoong i want to plot 2-link robot manipulator also, can you help me please? thanks.

Answer 1

[Jan]

Again: You simply cannot draw this:

You can use something like this as values for drawing:

T = [0.3, -0.7, 0, 21.3; ...
     0.7   0.3, 0, 22.5; ...
     0,    0,   1, 0; ...
     0,    0,   0, 1];

I could guess, that you have something like this available, but you do not mention it even after I ask for it. Therefore, please, specify the inputs of your problem exactly and post the corresponding Matlab code. Then explain, what you have done so far (with some code again, even if it is incomplete or not working) and where the problems occurred.

Please consider, that you are very familiar with your problem, but the readers of your question do not have the faintest idea of what you are talking about. E.g. "I have a 2 links robot": Have you build it mechanically and measure the physical angles? Is it a simulation of a rigid body system? Do you mean, that you have created the equations of motion? Is it 2D or 3D? 2 links can mean anything from 2 to 10 degrees of freedom. If we guess all these details, the solution will most likely have just a very vague connection to your problem.

[Cheng Yoong]

The example you gave is it a matrices?If it is,then that's what I mean. The values inside matrices I can calculate. Just need the idea how to use matrices to draw.=)

[Jan]

Have you read the "Getting Started" chapters of the documentation?

Read this also: "help line" and "help plot". Example:

"line([0, 10, 12], [0, 2, 7])" This draws a line from point {0,0} over {10,2} to {12,7}.

Answer 2

[Jan]

You cannot plot a formula. You need the numerical values of the trajectories for plotting.

Have you seen this:

• http://www.mathworks.com/matlabcentral/fileexchange/26660-robotarm
• http://www.mathworks.com/matlabcentral/fileexchange/25855-plot-and-animate-robot
• http://www.mathworks.com/matlabcentral/fileexchange/157-robot-demo
• http://www.mathworks.com/matlabcentral/fileexchange/24361-robotics
• http://www.mathworks.com/matlabcentral/fileexchange/15803-robot-simulator
• http://www.mathworks.com/matlabcentral/fileexchange/22637-robot-arm
• http://www.mathworks.com/matlabcentral/fileexchange/14932-3d-puma-robot-demo

[shee]

excuse me, do you have the plot and animate robot figure file? thanks

[reyam ahmed]

hello I want to plot 2-link robot manipulator, can you help me ?

[Jan]

@reyam ahmed: Perhaps. Are the shown links not useful already? I suggest to open a new thread and to ask a specific question. Then it is likely, that someone can help you.

[reyam ahmed]

Thank you Mr.jan I will do yhis.

[reyam ahmed]

yes this link doesn't useful for me.