📝Adding mass in inertia tensor's calculation

[rainingmp3]

Issue Type

• 🐛 Bug / Problem
• ✏️ Typo / Grammar
• 📖 Outdated Content
• 🚀 Enhancement

Generated by Generative AI

No response

Distribution

No response

Description

In Using-Xacro-to-Clean-Up-a-URDF-File.rst there is an example of how to use a macro function. The macro takes a mass as an input, but doesn't include it in inertia tensor's calculations. It doesn't really matter, but it would be better if these values get multiplied by mass, as it makes more sense physically.

As it is now:

<xacro:macro name="default_inertial" params="mass">
    <inertial>
            <mass value="${mass}" />
            <inertia ixx="1e-3" ixy="0.0" ixz="0.0"
                 iyy="1e-3" iyz="0.0"
                 izz="1e-3" />
    </inertial>
</xacro:macro>

Affected Pages/Sections

ros2_documentation/source/Tutorials/Intermediate/URDF/Using-Xacro-to-Clean-Up-a-URDF-File.rst

Line 7 in 2199aa3

Using Xacro to clean up your code

Screenshots or Examples (if applicable)

Suggested Fix

Should be:

<xacro:macro name="default_inertial" params="mass">
    <inertial>
            <mass value="${mass}" />
            <inertia ixx="${(1e-3)* mass}"   ixy="0.0" ixz="0.0"
                 iyy="${(1e-3) * mass}" iyz="0.0"
                 izz="${(1e-3) * mass}" />
    </inertial>
</xacro:macro>

Additional Context

No response

[fujitatomoya]

i think that looks like a small improvement, but one that makes the tutorial both more correct and more educational. can you open the PR? i am happy to review that.