Vrep (CoppeliaSim) Inverse kinematics tutorial (before version 4.2.0)

Tutorial link :
www.coppeliarob...
⚠️ 𝙉𝙤𝙩𝙚:
_after version 4.2.0, CoppeliaSim changed the IK method, please refer to this Official CoppeliaSim tutorial: www.coppeliaro...
_If you want to control the orientation of the robot, select "Mechanism is redundant" at 2:35, and select also ''alpha-beta" "Gamma" at 2:43.
⚠️𝐂𝐨𝐦𝐦𝐨𝐧 𝐯𝐢𝐞𝐰𝐞𝐫𝐬 𝐩𝐫𝐨𝐛𝐥𝐞𝐦𝐬 :
_ The robot falls apart when configuring joints in Inverse Kinematics Mode :
for the objects that are falling: double click on the object (in the scene hierarchy), click on "show dynamic properties dialog", uncheck "body is dynamic"
📛 Our Facebook page :
/ mechatronics-ninja-160...

[@jeantaylor661]

This is really helpful .However, I noticed that sometime the robot goes to a complicated directions

[@mechatronicsninja3806]

you are alright Jean, it has various explanation: this weird movement is due to :
1-The target is outside the workspace of the robot.
2-The robot is in a singularity point.

[@codenie749]

Very clear! Thank you

[@mechatronicsninja3806]

Glad it was helpful!

[@nad1061]

That's very nice. I've looked at your channel a little bit, you've become a robot arm master :).
There's something I'm curious about. Isn't it possible to implement a real robot arm with these drawings and these inverse kinematics calculations? I don't know much, but you seem to have completed everything.

[@mechatronicsninja3806]

Thank you so much.
I think you can. One solution to do so is to create a TCP/IP connection with the real robot. I don't know if you can directly write your code using vrep but you can connect vrep to Matlab (tcpip function) or Java (socket).
There are many other solutions which depend on the type of the robot and the protocols supported.

[@nad1061]

Can i retrieve inverse kinematic calculations from the V-rep as C ++ / C # (or anything) code?

[@mechatronicsninja3806]

Yes you can :
www.coppeliarobotics.com/helpFiles/en/apiOverview.htm
To establish the connection with c++, follow this steps (C/C++ client) :
www.coppeliarobotics.com/helpFiles/en/remoteApiClientSide.htm#c
all c++ remote API functions are available here:
www.coppeliarobotics.com/helpFiles/en/remoteApiFunctions.htm

[@nad1061]

Thank you so much. If I really want to do something like that, they're gonna help me a lot. But I'm scared of the fact that the mechanics of the robot arm is so hard to make. :)

[@mechatronicsninja3806]

You 're welcome .
If you just want to get the inverse kinematic of the TCP Cartesian position , you don't have to add any mechanical parts . You can just add the joints needed and link them (joint i sill be the parent of joint i+1 ) to get these results.
And if you know the D-H table of your robot You can automatically add the joints using "Denavit-Hartenberg joint creator" that exists under the tool folder.
Moreover, if you are using a commercial robot , before you start the creation of the parts. search on Grabcad , maybe you will get your model. You can then easily import it as .slt files ( file>import >mesh) or as urdf file (I created a video with more details).

[@zhangying1020]

I have a problem, the joints will fall when I simulate.Could you tell me how to solve this problem?Thanks.

[@zhangying1020]

In the forum,someone says we should select"hybrid operation"when we choose"inverse kinematics",so I wonder why you didn't select "hybrid operation" and the joints didn't fall.

[@ahmedkarlal5740]

check hybrid

[@jaykumar664]

Hey I was wondering if there was a way to extract the joint angles after the robot has moved to its target? Thanks for the tutorial

[@jaykumar664]

nvm I figured it out :)

[@dreudax3294]

Hey, may I know how you did this. I would like to do this too. Many Thanks

[@arduinobot932]

sir can you give lesson how to use inverse kinermatic in version 4.2.0

[@mechatronicsninja3806]

Hi, I will try to make a quick tutorial about it.

[@dreudax3294]

Hello, how can one get all the joint angles after the end effector is at a target position. Also how can one get the dh and inverse kinematics equations from the software??

[@mechatronicsninja3806]

Hi, you can use sim.getJointPosition ()
www.coppeliarobotics.com/helpFiles/en/regularApi/simGetJointPosition.htm
For the second question, I don't know if there is a method to directly get the DH parameters. For the previous version, there was a DH creator tool that allow you to add robot joints based on the DH setting.

[@dreudax3294]

@@mechatronicsninja3806 Thank you.

[@mechatronicsninja3806]

@@dreudax3294 You're welcome 🙂

[@loicsigni1613]

For some reasons when I double click on the axis tree item, it does not give me Inverse kinematic option. Any idea why?

[@mechatronicsninja3806]

Hi Loic, this is because you are using a newer version (more details on the description)