# Tag Info

### Rotation matrix sign convention confusion.

I think that the main issue is that you're trying to read your rotation matrices from left to right. The sign changes seem random, but actually cycle in an ordinary way. Below follows a more elaborate ...
• 562
Accepted

### Why do current manipulators tend to use 7 DoF instead of 6 DoF?

Adding a 7th joint, and still targeting a 6D pose, would result in a null space of at least one dimension anywhere in the workspace. That is basically one the reasons people may wish to use a 7-DOF ...
• 328
Accepted

### Forward kinematic and inverse kinematic... When to use what?

Let me give you a mathematician's perspective on the difference between the two kinds problems. Forward kinematics asks the question: given a certain input (i.e. control command), what will be the ...
• 1,258

### Forward kinematic and inverse kinematic... When to use what?

Forward kinematics uses joint angles (with known link lengths) to compute the tool position and orientation. Inverse kinematics uses tool position and orientation, to compute joint angles. Note: if ...
• 4,366
Accepted

• 4,335

### Finding inverse kinematics algorithm for a specific manipulator

To expand on Ugo's answer, some libraries that implement these general IK algorithms: OpenRave ROS MoveIt! Matlab Robotics Toolkit Orocos For people just starting out with kinematics, I highly ...
• 5,780
Accepted

### Robot arm reachability of a pose in Cartesian space

Nowadays we no longer employ exact solutions for the IK problem, simply because the number of degrees of freedom so as the number of constraints the final configuration needs to comply with make the ...
• 3,875