How to lock a joint from rotating freely or how to get a rotation value of joint that is between limits defined in the urdf file

[8bocian]

I'm creating the environment for the RL agent (bipedal walker) and I need to provide output observation for my RL algorithm but I'm not really sure how to get joint rotation value, I used getLinkState, getJointState and getJointInfo but it didn't output what I expected. Could somebody explain to me how to get the current rotation value of the joint or how to prevent the joint from rotating freely?