2 Introduction to Parameters

rslidar_sdk reads parameters from the configuration file config.yaml, which is stored in rslidar_sdk/config.

config.yaml contains two parts, the common part and the lidar part.

rslidar_sdk supports multi-LiDARs case. The common part is shared by all LiDARs, while in the lidar part, each child node is for an individual Lidar.

config.yaml is indentation sensitive! Please make sure the indentation is not changed after adjusting the parameters!

2.1 Common

The common part specifies the source of LiDAR packets, and where to publish point clouds and packets.

common:
  msg_source: 1                                         
  send_packet_ros: false                               
  send_point_cloud_ros: false                           

msg_source
- 0 – Unused. Never set this parameter to 0.
- 1 – LiDAR packets come from on-line LiDARs. For more details, please refer to Connect to online LiDAR and send point cloud through ROS
- 2 – LiDAR packets come from ROS/ROS2. It is used to decode from an off-line rosbag. For more details, please refer to Record rosbag & Replay it
- 3 – LiDAR packets come from a PCAP bag. For more details, please refer to Decode PCAP file and send point cloud through ROS
send_packet_ros
- true – LiDAR packets will be sent to ROS/ROS2.

The ROS Packet message is of a customized message type, so you can’t print its content via the ROS echo command. This option is used to record off-line Packet rosbags. For more details, please refer to the case of msg_source=2.

send_point_cloud_ros
- true – The LiDAR point cloud will be sent to ROS/ROS2.
The ROS point cloud type is the ROS official defined type – sensor_msgs/PointCloud2, so it can be visualized on the ROS rviz tool directly. It is not suggested to record the point cloud to rosbag, because its size may be very large. Please record Packets instead. Refer to the case of msg_source=2.

2.2 lidar

The lidar part needs to be adjusted for every LiDAR seperately.

lidar:
  - driver:
      lidar_type: RS128           
      msop_port: 6699             
      difop_port: 7788            
      start_angle: 0              
      end_angle: 360               
      min_distance: 0.2            
      max_distance: 200            
      use_lidar_clock: false        
      dense_points: false        
      pcap_path: /home/robosense/lidar.pcap                 
    ros:
      ros_frame_id: rslidar           
      ros_recv_packet_topic: /rslidar_packets    
      ros_send_packet_topic: /rslidar_packets    
      ros_send_point_cloud_topic: /rslidar_points      

lidar_type

Supported LiDAR types are listed in the README file.
msop_port, difop_port

The MSOP port and DIFOP port to receive LiDAR packets. If no data is received, please check these parameters first.
start_angle, end_angle

The start angle and end angle of the point cloud, which should be in the range of 0~360°. start_angle can be larger than end_angle.
min_distance, max_distance

The minimum distance and maximum distance of the point cloud.
use_lidar_clock
- true – Use the Lidar clock as the message timestamp
- false – Use the host machine clock as the message timestamp
dense_points

Whether to discard NAN points. The default value is false.
- Discard if true
- reserve if false.
pcap_path

The full path of the PCAP file. Valid if msg_source = 3.
ros_send_by_rows

Meaningful only for Mechanical Lidars, and valid if dense_points = false。
- true – send point cloud row by row
- false – send point cloud clolumn by column

2.3 Examples

2.3.1 Single Lidar Case

Connect to 1 LiDAR of RS128, and send point cloud to ROS.

common:
  msg_source: 1                                         
  send_packet_ros: false                               
  send_point_cloud_ros: true                           
lidar:
  - driver:
      lidar_type: RS128           
      msop_port: 6699             
      difop_port: 7788            
      start_angle: 0              
      end_angle: 360               
      min_distance: 0.2            
      max_distance: 200            
      use_lidar_clock: false        
    ros:
      ros_frame_id: rslidar           
      ros_recv_packet_topic: /rslidar_packets    
      ros_send_packet_topic: /rslidar_packets    
      ros_send_point_cloud_topic: /rslidar_points      

2.3.2 Multi Lidar Case

Connect to 1 LiDAR of RS128, and 2 LiDARs of RSBP, and send point cloud to ROS.

Pay attention to the indentation of the lidar part

common:
  msg_source: 1                                         
  send_packet_ros: false                               
  send_point_cloud_ros: true                           
lidar:
  - driver:
      lidar_type: RS128           
      msop_port: 6699             
      difop_port: 7788            
      start_angle: 0              
      end_angle: 360               
      min_distance: 0.2            
      max_distance: 200            
      use_lidar_clock: false        
    ros:
      ros_frame_id: rslidar           
      ros_recv_packet_topic: /middle/rslidar_packets    
      ros_send_packet_topic: /middle/rslidar_packets    
      ros_send_point_cloud_topic: /middle/rslidar_points      
  - driver:
      lidar_type: RSBP           
      msop_port: 1990             
      difop_port: 1991            
      start_angle: 0              
      end_angle: 360               
      min_distance: 0.2            
      max_distance: 200            
      use_lidar_clock: false        
    ros:
      ros_frame_id: rslidar           
      ros_recv_packet_topic: /left/rslidar_packets    
      ros_send_packet_topic: /left/rslidar_packets    
      ros_send_point_cloud_topic: /left/rslidar_points      
  - driver:
      lidar_type: RSBP           
      msop_port: 2010             
      difop_port: 2011            
      start_angle: 0              
      end_angle: 360               
      min_distance: 0.2            
      max_distance: 200            
      use_lidar_clock: false        
    ros:
      ros_frame_id: rslidar           
      ros_recv_packet_topic: /right/rslidar_packets    
      ros_send_packet_topic: /right/rslidar_packets    
      ros_send_point_cloud_topic: /right/rslidar_points      