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<p>Hi,</p>
<p>by copying or assigning the KDL::Tree the inertia information of
the root segment is not copied and is restored to zero.</p>
<p>The inertia information:</p>
<div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div><span style="color: #d4d4d4;">segment.</span><span style="color: #dcdcaa;">getInertia</span><span style="color: #d4d4d4;">().</span><span style="color: #dcdcaa;">getMass</span><span style="color: #d4d4d4;">()
</span><span style="color: #d4d4d4;"><span style="color: #d4d4d4;">segment.</span><span style="color: #dcdcaa;">getInertia</span><span style="color: #d4d4d4;">().</span><span style="color: #dcdcaa;">getCOG</span><span style="color: #d4d4d4;">()</span></span><span style="color: #d4d4d4;"></span><span style="color: #d4d4d4;"></span>
<div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div><span style="color: #d4d4d4;">segment.</span><span style="color: #dcdcaa;">getInertia</span><span style="color: #d4d4d4;">().</span><span style="color: #dcdcaa;">getRotationalInertia</span><span style="color: #d4d4d4;">()</span></div></div></div></div>
<p><br>
</p>
<p>Hier is the code:</p>
<div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div><span style="color: #d4d4d4;"> </span><span style="color: #569cd6;">bool</span><span style="color: #d4d4d4;"> is_success </span><span style="color: #d4d4d4;">=</span><span style="color: #d4d4d4;"> </span><span style="color: #dcdcaa;">kdl_parser::treeFromFile</span><span style="color: #d4d4d4;">(file, </span><span style="color: #569cd6;">this</span><span style="color: #d4d4d4;">-></span><span style="color: #9cdcfe;">kdlTree</span><span style="color: #d4d4d4;">);</span></div>
<div><span style="color: #d4d4d4;"> </span><span style="color: #dcdcaa;">printOutTree</span><span style="color: #d4d4d4;">(</span><span style="color: #569cd6;">this</span><span style="color: #d4d4d4;">-></span><span style="color: #9cdcfe;">kdlTree</span><span style="color: #d4d4d4;">);</span></div>
<div><span style="color: #d4d4d4;"> KDL::Tree </span><span style="color: #9cdcfe;">treeTest</span><span style="color: #d4d4d4;">(kdlTree);</span></div>
<div><span style="color: #d4d4d4;"> </span><span style="color: #dcdcaa;">printOutTree</span><span style="color: #d4d4d4;">(treeTest);</span></div></div></div>
<p>For test the urdf model of asguard was used:
<a class="moz-txt-link-freetext" href="https://git.hb.dfki.de/models-robots/asguard_v4/blob/master/urdf/asguard_v4.urdf">https://git.hb.dfki.de/models-robots/asguard_v4/blob/master/urdf/asguard_v4.urdf</a><br>
</p>
<p>The original, kdlTree:<br>
</p>
<p>---body<br>
<b>Mass: 2</b><b><br>
</b><b>COG: 0.035 0 0.07825</b><b><br>
</b><b>RotationalInertia: 0.0281261 0 -0.0054775 0 0.0641161 0
-0.0054775 0 0.05125</b><br>
.......<br>
---wheel_front_right_motor<br>
Mass: 0.1<br>
COG: -0.00031 -0.00016 0.00047<br>
RotationalInertia: 0.00176002 -4.96e-09 1.457e-08 -4.96e-09
0.00346003 7.52e-09 1.457e-08 7.52e-09 0.00176001</p>
<p><br>
</p>
<p>Its copy, treeTest:</p>
<p>---body<br>
<b>Mass: 0</b><b><br>
</b><b>COG: 0 0 0</b><b><br>
</b><b>RotationalInertia: 0 0 0 0 0 0 0 0 0</b><br>
........<br>
---wheel_front_right_motor<br>
Mass: 0.1<br>
COG: -0.00031 -0.00016 0.00047<br>
RotationalInertia: 0.00176002 -4.96e-09 1.457e-08 -4.96e-09
0.00346003 7.52e-09 1.457e-08 7.52e-09 0.00176001</p>
<p><br>
</p>
<p>Has someone know more about this issue? <br>
</p>
<p>I tried with our kdl version (commit:
264ef3f7c4ad553e7a391e0f104fda1ec5051925) and with the newest kdl
version (commit: d798f594552cb6f6223981b9c304d3db2b6a7d18). Both
versions give the same result.</p>
<p><br>
</p>
<p>With best regards,</p>
<p>Anna<br>
</p>
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