RoboSense LiDAR RS-Bpearl, User Manual

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RS-Bpearl User manual
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4.2.Point Cloud Display
4.2.1. Coordinate Mapping
Since the data packet output by the LiDAR only provides the horizontal rotation angle and
distance infomation, in order to present a 3D point cloud image, the angle and distance
information in polar coordinates need to be converted into x, y, z coordinates in the Cartesian
coordinate system, and the conversion formula is as follows:
� = � ��� ( �) ��� ( � + �);
� = � ��� ( �) ��� ( � + �);
� = � ��� ( �);
Where
�
is the measured distance,

is the vertical angle of the laser,

is the horizontal
rotation angle of the laser in the Polar Coordinate System, and x, y, z are the coordinate values in
the Cartesian Coordinate System.

and
�
can be obtained from the DIFOP data packets, please refer to B.14 and B.15 in
Appendix B for details.
Figure 4-1 LiDAR Polar Coordinates
Note 1: ROS source code of RS-Helios has by default completed the coordinate conversion to conform to the
right-handed coordinate system of ROS. The X-axis of ROS is the positive Y direction in Figure 4-1, and the Y-axis
of ROS is the negative X direction in Figure 4-1.
Note 2: The origin of the LiDAR sensor coordinate is at the center of the LiDAR base.