IK for dobot magician

[sumitsingh]

Hello Everyone, i am a beginner in coppeliasim and i was doing a project with dobot magician robot present inside the simulator.It is a pick and place project and in this project i need to solve the inverse kinematics for the same robot but i am not able to do so as it gives the wrong values for joints. If anybody out there have done project on IK of this robot and can share their experience that would be very helpful.
Also if you can, please share also the frame reference for dh parameters so i can calculate the joints angles manually.
I did try to use motor1,motor2,auxJoint1,auxJoint2 as the 4 joints to reach the position require but wasn't able to make it work.
Thanks

[coppelia]

Hello,

the Dobot robot is a bit special as it has 2 trapezoidal loops. There are many different ways to solve this via IK. The simplest is to identify 4 driving joints (motors), going from tip to base, as one would do with a simple kinematic chain. e.g.:

• tip rotation
• elbow
• base arm
• base rotation

With above, you can already have your robot move in IK. It will however look a bit weird, since the 2 trapezoidal loops would not be closed and not be active. To solve this, simply consider each loop as a kinematic chain on its one, that needs to be solved. So you'd end up with 3 IK elements that need to be solved.

Cheers

[sumitsingh]

Ok Thanks I will try to solve it in this way!