I am rather new to screw theory and also lost in robotics books' formulas. we have a simulator of a robot arm within Mujoco physics engine and I'm wondering how I can calculate wrench and twist in the local and base coordinate frame.

In the simulator what I have available is the end-effector's translational (jacp) and rotational(jacr) Jacobians. In addition I can obtain joins positions, velocities, accelerations and torque sensors' readings along with some other time dependent variables that are usually available in simulators.

  • $\begingroup$ What are you hoping to calculate the wrench and twist of? The end effector? Each link? What would you consider to be the "local" and "base" frames? Unfortunately, it's hard to answer your question without more specifics. $\endgroup$ Commented Sep 16, 2021 at 13:48
  • $\begingroup$ Welcome to Robotics azerila, but I'm afraid that it is not clear what you are asking. We prefer practical, answerable questions based on actual problems that you face, so it's a good idea to include details of what you want to achieve, what you tried, what you saw & what you expected to see. Please take a look at How to Ask & tour for more information on how stack exchange works and work through the Robotics question checklist to edit your question to make it clearer. $\endgroup$
    – Ben
    Commented Jan 24, 2022 at 20:23