里程计校准

这个行为树驱动机器人以逆时针方式绕正方形行驶三次，使用DriveOnHeading和Spin行为。机器人将以0.2（m/s）的速度行驶2米，然后进行90度转弯。这是一个用于测量里程计精度的原始实验，并且可以用于调整与里程计相关的参数以提高质量。

替代文本 
<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Repeat num_cycles="3">
      <Sequence name="Drive in a square">
        <DriveOnHeading dist_to_travel="2.0" speed="0.2" time_allowance="12"/>
        <Spin spin_dist="1.570796" is_recovery="false"/>
        <DriveOnHeading dist_to_travel="2.0" speed="0.2" time_allowance="12"/>
        <Spin spin_dist="1.570796" is_recovery="false"/>
        <DriveOnHeading dist_to_travel="2.0" speed="0.2" time_allowance="12"/>
        <Spin spin_dist="1.570796" is_recovery="false"/>
        <DriveOnHeading dist_to_travel="2.0" speed="0.2" time_allowance="12"/>
        <Spin spin_dist="1.570796" is_recovery="false"/>
      </Sequence>
    </Repeat>
  </BehaviorTree>
</root>