I am doing robotic arm simulation in Matlab Simulink but get the error. How I can resolve this.

enter image description here

My model given below. enter image description here

Other details: 1. image of coordinates with world coordinates. 2. 6 DOF joint setting enter image description here enter image description here

  • $\begingroup$ Could you please add the orientation of the revolute joints? Preferably in world coordinate system? Also adding the exact configuration of the 6DOF joint would help. $\endgroup$
    – 50k4
    Mar 3 '17 at 7:22
  • $\begingroup$ Hello @50k4, As you asked me the details therefore I am sharing my full folder on dropbox. Kindly comment if you face any problem in accessing the folder. Looking for your help .Thanks. dropbox.com/sh/vvjw2rvoba1g9jj/AABX5LKmpOkKXmRGpomtbyQVa?dl=0 $\endgroup$ Mar 3 '17 at 11:35
  • $\begingroup$ Posting the details of the joints in the question would help more, I don not have access to Matlab currently $\endgroup$
    – 50k4
    Mar 3 '17 at 11:43
  • $\begingroup$ Hello 50k4, as you asked I added two more images in question. I hope you are asking for same. $\endgroup$ Mar 3 '17 at 12:25
  • $\begingroup$ I did a similar simulation using SolidWorks: youtube.com/watch?v=crJXUlzJ918 $\endgroup$
    – LCarvalho
    Feb 19 '18 at 20:02

You cane find a detailed explanation on how to set the joint actuation types here. It seems that you need to set the torques as automatically computed, otherwise these are set to zero.

Furthermore, as it seems, the robot only moves in the x-y plane, but there is a z offset wrt the world coordinate system. Please make sure that this is handled correctly (you can use the same offset before the 6dof joint or you can allow for z axis movement)

  • $\begingroup$ Thanks 50k4, As you suggest my that error vanished but new error is coming as shown. An error occurred while running the simulation and the simulation was terminated Derivative of state 'Revolute3.Rz.w' in block 'rob/Revolute3' at time 22.91008778271366 is not finite. The simulation will be stopped. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances). .....continue on next comment. $\endgroup$ Mar 7 '17 at 7:23
  • $\begingroup$ .....continue from previous comment... i tried to solve it by changing solver type, step size but all are in vein. Can you suggest me what modification should I do with solver type, step size etc. to work it perfect. $\endgroup$ Mar 7 '17 at 7:28
  • $\begingroup$ Could it be that it is in fact a singular pose of the robot? In a singular position, when you try to compute the joint velocities from the Cartesian velocities the results is an infinite value. Industrial robot controllers have ways to cope with this, but these techniques cannot be use when you rely on a solver to solve your model equations. $\endgroup$
    – 50k4
    Mar 7 '17 at 10:45
  • $\begingroup$ Another option is that the signal generator you are using the generate e reference trajectroy has a high jump in position and the numerical derivation gives an infinite velocity already for the Cartesian velocity. Try to use smooth motions for the Cartesian reference trajectroy and see if the problems still shows up $\endgroup$
    – 50k4
    Mar 7 '17 at 10:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.