# Questions tagged [jacobian]

The Jacobian is the matrix of partial derivatives of a function. For robot arms, the Jacobian relates joint velocities to end-effector velocity. Jacobian Inverse Kinematic method is one method to solve inverse kinematic problems.

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### When not to use pseudoinverse?

I know this equation: $\tau = J^T f$. In my case, the Jacobian $J$ is not square. Is it valid to use the pseudoinverse of $J^T$ to calculate end effector forces $f$ based on joint torques $\tau$? I ...
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### Cartesian control for $z$ vector of end effector frame to point towards a specific direction

Consider a robotic manipulator with 7-DOF (all joints are revolute) that accepts joint velocities as execution commands. What I am trying to achieve is the following: I want to calculate the ...
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### Cartesian Velocity Control between Two 3D Poses

I am really struggling to understand how to do Cartesian velocity control when 3D rotations are involved. So, below is a very simple example which I am hoping somebody can help me with. Let's say the ...
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### Jacobian to determine the linear velocity of each node (DOF 3 RRR robot arm)

I've done the FK and IK for this robot: On those I seem to be able to get to the positions I want on the simulator so I'm assuming nothing is wrong with my FK and IK calculations. I've tried to ...
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### Inverse Kinematics with Orientations

Let's say I have a robot consisting of a base $B$ and a manipulator $M$. The pose of the manipulator can be expressed as the transformation matrix $T_{BM}$. I also have a goal $G$ which I want to move ...
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### How to calculate twist and wrench in local and global frames

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 ...
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### Why with the pseudo-inverse it is possible to invert the Jacobian matrix even in a singular configuration?

Consider the following situation: I have a robotic arm manipulator with all revolute joints, for example consider a 2R planar manipulator. We know that if we compute the direct kinematics of it, anf ...
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### How do I compute the derivative of the Jacobian with Matlab?

I am studying robotics, and I am trying to write a Matlab code for computing the derivative of the jacobian matrix. The formula for computing the derivative of the Jacobian is the following: so it ...
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### Inverse Kinematics Tools [closed]

I am looking for inverse kinematics library (preferably compatible with ROS) that includes functions to calculate inverse-jacobian to go from end-effector velocity (twist) to joint velocities. I've ...