# Questions tagged [joint]

The point of contact between elements of a robot with the parts that surround and support it

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### DH Matrix to homogeneous transformation matrix for each joint

Given a DH matrix for a set of joints, how would you convert the data into homogeneous transformation matrices for each joint? I've looked online, but can't find a good tutorial.
• 21
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### Joint angle correction using LM

I have a camera mounted on a rotational joint. I need to calibrate the extrinsics of this camera. I can fix the camera at an estimated angle (facing the ceiling). Then I want to get the real angle. ...
• 681
1 vote
139 views

### What type of mechanism is this?

Held and rotated by the knurled ends, one in each hand, the silver spokes rise and fall in order for the assembly to rotate. What is it, some companies' salesmen show tool? Found in an old building, ...
• 113
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### Denavit–Hartenberg parameters of a robot with spherical wrist

What are valid values for the Denavit-Hartenberg parameters $d$ and $a$ (sometimes called $r$) of the last 3 links of a robot with spherical wrist? From this reference, "A spherical joint can be ...
• 123
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### What do we call a coupling with infinite range of rotation

In most situations, range of motion is limited by the fact that we need to carry power or information past a joint. So, past a certain point there are either cables in the way, or the cables would ...
• 249
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### What is the name of this mechanical linkage?

I am trying to find a joint like these for a robot I'm building. It is often called a swivel joint or a universal joint, but with a modified spider. I can't find one anywhere and would prefer not to ...
• 31
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### Building Robotic arm joint

I am very new to robotic design and I need to determine what parts I will need to assemble an arm joint. The joint will contain one timing belt pulley which a remote motor will be turning, a forearm ...
• 215
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### restricting range of motion with complex constraints

I am looking for a way to restrict a robot's range of motion, using complex constraints such as not tearing of a cable attached to the robot. Take an articulated 6-axis robot arm as shown below, with ...
• 369
The forward kinematics of a robot arm can be solved easily. We can represent each joint using Denavit–Hartenberg transformation matrices. For example, if the $i^{th}$ joint is a linear actuator, it ...