大疆Mid360雷达使用教程总结

Reference:

https://github.com/Livox-SDK/livox_ros_driver2

1. 下载编译安装Livox-SDK2

Reference:

https://github.com/Livox-SDK/Livox-SDK2/blob/master/README.md

下载编译安装Livox-SDK2：

git clone https://github.com/Livox-SDK/Livox-SDK2.git

cd ./Livox-SDK2/

mkdir build

cd build

cmake .. && make -j

sudo make install

编译生成的库文件为静态库，库文件安装路径为"/usr/local/lib"，头文件安装路径为"/usr/local/include"。

如果需要移除Livox-SDK2：

shell 复制代码

$ sudo rm -rf /usr/local/lib/liblivox_lidar_sdk_*
$ sudo rm -rf /usr/local/include/livox_lidar_*

2. 下载编译Livox ROS Driver 2

下载Livox ROS Driver 2

shell 复制代码

mkdir -p catkin_livox_ros_driver2/src/livox_ros_driver2

git clone https://github.com/Livox-SDK/livox_ros_driver2.git

For ROS1

以ROS Noetic环境下编译为例：

shell 复制代码

source /opt/ros/noetic/setup.sh

cd catkin_livox_ros_driver2/src/livox_ros_driver2

./build.sh ROS1

For ROS2 Foxy

shell 复制代码

source /opt/ros/foxy/setup.sh

cd catkin_livox_ros_driver2/src/livox_ros_driver2

./build.sh ROS2

For ROS2 Humble

shell 复制代码

source /opt/ros/humble/setup.sh

source /opt/ros/humble/setup.sh

./build.sh humble

3. 运行Livox ROS Driver 2

注意，如果运行如下命令后Rviz中没有显示点云数据，则有可能是雷达配置问题。

这里需要的配置包括：

将点云格式设置为PointXYZRTLT，对应参数为xfer_format=0，其位于ROS1的launch文件rviz_MID360.launch中或ROS2的launch文件rviz_MID360_launch.py中
设置雷达ip地址。查看雷达背后的id码，以47MDL960020112为例，其最后两位即为当前雷达的默认ip地址，即雷达的出厂默认ip地址为192.168.1.112。对应需要设置参数为文件MID360_config.json中的ip。
设置目标主机ip地址，即连接雷达和雷达进行通信的主机ip地址。这里需要设置到相同网段，这里设置为192.168.1.50，则对应需要在文件MID360_config.json中指定host_net_info的ip地址。

完整的文件MID360_config.json如下：

json 复制代码

{
  "lidar_summary_info" : {
    "lidar_type": 8
  },
  "MID360": {
    "lidar_net_info" : {
      "cmd_data_port": 56100,
      "push_msg_port": 56200,
      "point_data_port": 56300,
      "imu_data_port": 56400,
      "log_data_port": 56500
    },
    "host_net_info" : {
      "cmd_data_ip" : "192.168.1.50",
      "cmd_data_port": 56101,
      "push_msg_ip": "192.168.1.50",
      "push_msg_port": 56201,
      "point_data_ip": "192.168.1.50",
      "point_data_port": 56301,
      "imu_data_ip" : "192.168.1.50",
      "imu_data_port": 56401,
      "log_data_ip" : "",
      "log_data_port": 56501
    }
  },
  "lidar_configs" : [
    {
      "ip" : "192.168.1.112",
      "pcl_data_type" : 1,
      "pattern_mode" : 0,
      "extrinsic_parameter" : {
        "roll": 0.0,
        "pitch": 0.0,
        "yaw": 0.0,
        "x": 0,
        "y": 0,
        "z": 0
      }
    }
  ]
}

For ROS

shell 复制代码

cd catkin_livox_ros_driver2

source devel/setup.sh

roslaunch livox_ros_driver2 rviz_MID360.launch

For ROS2

shell 复制代码

cd catkin_livox_ros_driver2

source install/setup.sh

ros2 launch livox_ros_driver2 rviz_MID360_launch.py

4. ROS1和ROS2的launch文件

ROS的启动文件位于如下目录：

catkin_livox_ros_driver2/src/livox_ros_driver2/launch_ROS1

ROS2的启动文件位于如下目录：

catkin_livox_ros_driver2/src/livox_ros_driver2/launch_ROS2

不同的启动文件对应不同的雷达和配置，并在不同的场景中使用。

launch file name	Description
rviz_HAP.launch	Connect to HAP LiDAR device Publish pointcloud2 format data Autoload rviz
msg_HAP.launch	Connect to HAP LiDAR device Publish livox customized pointcloud data
rviz_MID360.launch	Connect to MID360 LiDAR device Publish pointcloud2 format data Autoload rviz
msg_MID360.launch	Connect to MID360 LiDAR device Publish livox customized pointcloud data
rviz_mixed.launch	Connect to HAP and MID360 LiDAR device Publish pointcloud2 format data Autoload rviz
msg_mixed.launch	Connect to HAP and MID360 LiDAR device Publish livox customized pointcloud data

5. 雷达参数配置之launch文件

Livox_ros_driver2的所有内部参数配置均位于launch文件中。

如下为三个常用参数的功能描述，包括

设置点云发布频率，最高为100Hz
多个雷达时，设置每个雷达的话题名称
设置点云消息格式，包括

Parameter	Detailed description	Default
`publish_freq`	Set the frequency of point cloud publish Floating-point data type, recommended values 5.0, 10.0, 20.0, 50.0, etc. The maximum publish frequency is 100.0 Hz.	10.0
`multi_topic`	If the LiDAR device has an independent topic to publish pointcloud data 0 -- All LiDAR devices use the same topic to publish pointcloud data 1 -- Each LiDAR device has its own topic to publish point cloud data	0
`xfer_format`	Set pointcloud format 0 -- Livox pointcloud2(`PointXYZRTLT`) pointcloud format 1 -- Livox customized pointcloud format 2 -- Standard pointcloud2 (`pcl :: PointXYZI`) pointcloud format in the PCL library (just for ROS)	0

设置点云发布频率

打开对应的launch文件，配置参数publish_freq

设置点云消息的数据格式

打开对应的launch文件，配置参数xfer_format。这里支持以下三种格式：

格式代号	消息类型	说明
0	`PointXYZRTLT`	Livox pointcloud2pointcloud format
1	`livox_ros_driver2::CustomMsg`	Livox customized pointcloud format
2	`pcl::PointXYZI`	Standard pointcloud2 pointcloud format in the PCL library (just for ROS)

其中，Livox自定义的用于支持PCL库的PointXYZRTLT点格式的定义如下：

float32 x               # X axis, unit:m
float32 y               # Y axis, unit:m
float32 z               # Z axis, unit:m
float32 intensity       # the value is reflectivity, 0.0~255.0
uint8   tag             # livox tag
uint8   line            # laser number in lidar
float64 timestamp       # Timestamp of point

在C++中可以定义如下：

cpp 复制代码

#include <pcl/point_cloud.h>
#include <pcl/point_types.h>
#include <pcl/impl/pcl_base.hpp>

/**
 * @brief Livox Mid360 Point Type
 */
namespace mid360_ros {
struct Point
{
  PCL_ADD_POINT4D
  PCL_ADD_INTENSITY
  std::uint8_t tag;     // livox tag --- 对于Mid360, 其取值为[0,1,2,3,4]
  std::uint8_t line;    // laser number in lidar --- 对于Mid360, 其取值为[0,1,2,3]，即总共4条激光线，每次采样四个点的线号依次为0,1,2,3
  double timestamp;     // 单位为ns的绝对时间戳
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
} EIGEN_ALIGN16;
}
POINT_CLOUD_REGISTER_POINT_STRUCT(mid360_ros::Point,
  (float, x, x)(float, y, y)(float, z, z)
  (float, intensity, intensity)
  (std::uint8_t, tag, tag)
  (std::uint8_t, line, line)
  (double, timestamp, timestamp)
)

另外一种Livox自定义的点云数据格式为：

std_msgs/Header header     # ROS standard message header
uint64          timebase   # The time of first point
uint32          point_num  # Total number of pointclouds
uint8           lidar_id   # Lidar device id number
uint8[3]        rsvd       # Reserved use
CustomPoint[]   points     # Pointcloud data

上述点云数据格式中的一个点的格式（CustomPoint）的定义如下：

uint32  offset_time     # offset time relative to the base time
float32 x               # X axis, unit:m
float32 y               # Y axis, unit:m
float32 z               # Z axis, unit:m
uint8   reflectivity    # reflectivity, 0~255
uint8   tag             # livox tag
uint8   line            # laser number in lidar

设置多个雷达的点云话题

打开对应的launch文件，配置参数multi_topic

6. 雷达参数配置之Json文件

修改雷达的IP、端口

Lidar的IP和端口等设置位于config文件夹下的json-style的配置文件中。

参数说明如下：

Parameter	Type	Description	Default
`ip`	String	Ip of the LiDAR you want to config	192.168.1.100
`pcl_data_type`	Int	Choose the resolution of the point cloud data to send 1 -- Cartesian coordinate data (`32 bits`) 2 -- Cartesian coordinate data (`16 bits`) 3 --Spherical coordinate data	1
`pattern_mode`	Int	Space scan pattern 0 -- non-repeating scanning pattern mode 1 -- repeating scanning pattern mode 2 -- repeating scanning pattern mode (low scanning rate)	0
`blind_spot_set` (Only for HAP LiDAR)	Int	Set blind spot Range from 50 cm to 200 cm	50
`extrinsic_parameter`		Set extrinsic parameter The data types of "roll" "picth" "yaw" are float The data types of "x" "y" "z" are int

示例如下：

json 复制代码

{
  "lidar_summary_info" : {
    "lidar_type": 8  # protocol type index, please don't revise this value
  },
  "HAP": {
    "device_type" : "HAP",
    "lidar_ipaddr": "",
    "lidar_net_info" : {
      "cmd_data_port": 56000,  # command port
      "push_msg_port": 0,
      "point_data_port": 57000,
      "imu_data_port": 58000,
      "log_data_port": 59000
    },
    "host_net_info" : {
      "cmd_data_ip" : "192.168.1.5",  # host ip (it can be revised)
      "cmd_data_port": 56000,
      "push_msg_ip": "",
      "push_msg_port": 0,
      "point_data_ip": "192.168.1.5",  # host ip
      "point_data_port": 57000,
      "imu_data_ip" : "192.168.1.5",  # host ip
      "imu_data_port": 58000,
      "log_data_ip" : "",
      "log_data_port": 59000
    }
  },
  "lidar_configs" : [
    {
      "ip" : "192.168.1.100",  # ip of the LiDAR you want to config
      "pcl_data_type" : 1,
      "pattern_mode" : 0,
      "blind_spot_set" : 50,
      "extrinsic_parameter" : {
        "roll": 0.0,
        "pitch": 0.0,
        "yaw": 0.0,
        "x": 0,
        "y": 0,
        "z": 0
      }
    }
  ]
}

当连接多个激光雷达时，将不同激光雷达对应的对象添加到 "lidar_configs" 数组中即可。

示例如下：

json 复制代码

{
  "lidar_summary_info" : {
    "lidar_type": 8  # protocol type index, please don't revise this value
  },
  "HAP": {
    "lidar_net_info" : {  # HAP ports, please don't revise these values
      "cmd_data_port": 56000,  # HAP command port
      "push_msg_port": 0,
      "point_data_port": 57000,
      "imu_data_port": 58000,
      "log_data_port": 59000
    },
    "host_net_info" : {
      "cmd_data_ip" : "192.168.1.5",  # host ip
      "cmd_data_port": 56000,
      "push_msg_ip": "",
      "push_msg_port": 0,
      "point_data_ip": "192.168.1.5",  # host ip
      "point_data_port": 57000,
      "imu_data_ip" : "192.168.1.5",  # host ip
      "imu_data_port": 58000,
      "log_data_ip" : "",
      "log_data_port": 59000
    }
  },
  "MID360": {
    "lidar_net_info" : {  # Mid360 ports, please don't revise these values
      "cmd_data_port": 56100,  # Mid360 command port
      "push_msg_port": 56200,
      "point_data_port": 56300,
      "imu_data_port": 56400,
      "log_data_port": 56500
    },
    "host_net_info" : {
      "cmd_data_ip" : "192.168.1.5",  # host ip
      "cmd_data_port": 56101,
      "push_msg_ip": "192.168.1.5",  # host ip
      "push_msg_port": 56201,
      "point_data_ip": "192.168.1.5",  # host ip
      "point_data_port": 56301,
      "imu_data_ip" : "192.168.1.5",  # host ip
      "imu_data_port": 56401,
      "log_data_ip" : "",
      "log_data_port": 56501
    }
  },
  "lidar_configs" : [
    {
      "ip" : "192.168.1.100",  # ip of the HAP you want to config
      "pcl_data_type" : 1,
      "pattern_mode" : 0,
      "blind_spot_set" : 50,
      "extrinsic_parameter" : {
        "roll": 0.0,
        "pitch": 0.0,
        "yaw": 0.0,
        "x": 0,
        "y": 0,
        "z": 0
      }
    },
    {
      "ip" : "192.168.1.12",  # ip of the Mid360 you want to config
      "pcl_data_type" : 1,
      "pattern_mode" : 0,
      "extrinsic_parameter" : {
        "roll": 0.0,
        "pitch": 0.0,
        "yaw": 0.0,
        "x": 0,
        "y": 0,
        "z": 0
      }
    }
  ]
}

修改雷达的扫描模式 --- 不支持

很遗憾，从官方Github上的issues看，MID360当前尚不支持重复扫描模式，即只支持默认的非重复扫描模式 ！尝试修改pattern_mode参数并不会起作用。

具体可见：

https://github.com/Livox-SDK/livox_ros_driver2/issues/36