For a link-joint system in robotics, the link at the end of the chain is usually called as the end effector. If I have the desired position and orientation of the end effector in the world space, then I can calculate the joint values required to reach that desired position. This is referred to as Inverse Kinematics (IK). Note that the joint values should reside within the joint limits.
Athough there is a built-in function in pybullet for IK, still we can implement one on our own depending on the problem statement.
The task is to pin a 2R planar arm on the boundary of a rotating disc. While the disc is rotating, the end effector of the arm should be at a fixed point. I have attached the URDF file and the solution fkik.py file.
Following is the running display of the above mentioned task:
