RoboSense LiDAR RS-Helios-16P - Point Cloud Display; Ranging Capability per Channel; Coordinate Mapping for Point Cloud

RS-Helios-16P User Manual
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Table 5 Ranging Capability of LiDAR Channel
Channel No.
Vertical Angle（°）
10% NIST（m）
Range（m）
1
13°
90
120
2
15°
90
120
3
9°
90
150
4
11°
90
120
5
5°
90
150
6
7°
90
150
7
1°
90
150
8
3°
90
150
9
-3°
90
150
10
-1°
90
150
11
-7°
90
150
12
-5°
90
150
13
-11°
90
120
14
-9°
90
150
15
-15°
90
120
16
-13°
90
120
5.2 Point Cloud Display
5.2.1 Coordinate Mapping
Since the data packet output by the LiDAR only provides the horizontal rotation angle and
distance parameters, 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:
{
𝑥=𝑟𝑐𝑜𝑠(𝜔)𝑠𝑖𝑛(𝛼);
𝑦=𝑟 𝑐𝑜𝑠(𝜔)𝑐𝑜𝑠(𝛼);
𝑧=𝑟 𝑠𝑖𝑛(𝜔);
Where 𝑟 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.
Note 1: ROS source code of RS-Helios-16P 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 1, and the Y-axis of
ROS is the negative X direction in Figure 1.
Note 2: The origin of the LiDAR sensor coordinate is 63.5mm above the LiDAR base, on the center axis.
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