The process of assembling links and joints

Now that you have a URDF file with one link, let’s add another link, and connect them with a joint. This joint will be used to generate a TF.

Properly assembling two links with a joint is the main problem anybody faces when learning URDF. There are several origins and axes you can modify, and getting two parts to be correctly placed between each other, with the correct movement, can be challenging.

In this section, we will focus on that process, so it becomes easier for you. I have condensed it into five steps that you can follow in the order every time you add a new link.

After you get confident with the process, you will be able to create a URDF for any kind of robot. A complete robot model is just a sequence of links connected to each other. If you correctly understand how to do it for two links, adding twenty more links won’t be that difficult.

We will also explore the different kinds of joints you can use in...