V2 ROS2 interface reference

Overview

This page describes the ROS2 topics and services provided by lx_camera_ros in the V2 localization module.

Compile

Install the Qt5 Core and Network components. Installation commands vary by Linux distribution; the following example uses Ubuntu:

sudo apt install qtbase5-dev qtbase5-dev-tools libqt5network5

Download the libzip source from the libzip download page and compile it according to the official instructions. Run the following command from /lx_camera_ros:

./build.sh

Run

Recompile after changing the YAML configuration file. Changes do not take effect until the project is rebuilt.

./start.sh

ROS2 topic interfaces

Before testing an interface, power on the camera, wait about 30 seconds, and start the ROS2 SDK node.

Use case	Related topics
Localization	Pose, localization status, map switching, and relocalization
Mapping	Mapping status and progress
Maintenance and configuration	Storage usage, faulty modules, parameter settings, and map download

Receive localization pose

ROS2 continuously receives the camera’s x, y, and theta values, publishes the values and the quaternion converted from theta to LxCamera_LocationPoseResult, and broadcasts the pose through TF.

ros2 topic echo /LxCamera_LocationPoseResult

Receive localization status

ROS2 receives the camera’s localization status (true or false) at 1 Hz and publishes it as std_msgs::msg::Bool on LxCamera_LocationResult.

ros2 topic echo /LxCamera_LocationResult

Receive camera storage usage

ROS2 receives the camera’s storage usage ratio at 2 Hz and publishes it as std_msgs::msg::Float32 on LxCamera_Capacity_Status.

ros2 topic echo /LxCamera_Capacity_Status

Receive the faulty module name

ROS2 receives the name of a faulty module from the camera and publishes it as std_msgs::msg::String on LxCamera_Module_Error.

ros2 topic echo /LxCamera_Module_Error

Receive mapping progress

After mapping starts, ROS2 publishes the progress (0–100) as std_msgs::msg::Int32 on LxCamera_Mapping_Progress.

ros2 topic echo /LxCamera_Mapping_Progress

Receive mapping status

After mapping starts, ROS2 publishes the mapping status as std_msgs::msg::Bool on LxCamera_MappingState.

ros2 topic echo /LxCamera_MappingState

Set parameters

Publish a std_msgs::msg::String message to LxCamera_SetParam. The message contains nine floating-point values separated by commas: x,y,z,yaw,pitch,roll,x,y,yaw. The first six values define the camera pose; the last three define the LiDAR pose. After a successful update, the corresponding values in the [Laser1] and [Camera1] sections of /home/fr1511b/hontai/params/config_install_FL21500HAF.ini are updated.

source install/setup.bash
ros2 topic pub -1 /LxCamera_SetParam std_msgs/msg/String "{data: '1,1,1,1,1,1,1,1,1'}"

Switch maps

Publish a std_msgs::msg::String message containing the name of a completed map to LxCamera_SwitchMap. Refresh the camera web interface. If the displayed map name changes, the switch succeeded.

source install/setup.bash
ros2 topic pub -1 /LxCamera_SwitchMap std_msgs/msg/String "{data: 'pf'}"

Download a map

Publish a std_msgs::msg::String message to LxCamera_DownloadMap.
The message contains two fields: save_path, an absolute path on the host computer, and mapname, the .zip file name of a completed map on the camera.
After a successful download, the specified host path contains the map archive. Extract it to obtain a PGM map file and a YAML configuration file.

# Enter the lx_camera_ros2_ws directory.
source install/setup.bash
ros2 topic pub -1 /LxCamera_DownloadMap std_msgs/msg/String "{data: '/home/zsure/LANXIN\,pf'}"

Upload odometry

Publish nav_msgs::msg::Odometry data to /sim/odom (the topic can be changed).

# Enter the lx_camera_ros2_ws directory.
source install/setup.bash
ros2 topic pub /odom nav_msgs/msg/Odometry "header: stamp: {sec: 0, nanosec: 0} frame_id: 'odom' child_frame_id: 'base_link' pose: pose: position: x: 1.0 y: 2.0 z: 0.0 orientation: x: 0.0 y: 0.0 z: 0.0 w: 1.0 covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0] twist: twist: linear: x: 0.5 y: 0.0 z: 0.0 angular: x: 0.0 y: 0.0 z: 0.1 covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]"

Relocalize

Publish geometry_msgs::msg::PoseWithCovarianceStamped data to LxCamera_UploadReloc.
The pose contains the LiDAR pose: x, y, and yaw.
Relocalization succeeds when the position shown in the camera web interface updates to the sent pose.

ros2 topic pub -1 /LxCamera_UploadReloc geometry_msgs/msg/PoseWithCovarianceStamped "{
  header: {frame_id: ''},
  pose: {
    pose: {
      position: {x: 0.0, y: 0.0, z: 0.0},
      orientation: {x: 0, y: 0, z: -0.694658, w: 0.71934}
    },
    covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
                 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
                 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
                 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
                 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
                 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
  }
}"

Quaternions are constrained and must not be filled in arbitrarily. Use the Euler-to-quaternion converter to convert an Euler yaw angle to quaternion xyzw values.

Message type prefixes

The host computer communicates with the camera over UDP. The first four bytes of each message identify the interface data type:

mapping_prefix = "aced220d";          // Enable mapping
setparam_prefix = "aced220e";         // Set camera and LiDAR parameters
UploadScan_prefix = "aced2209";       // Upload laser scan data to the camera
odom_prefix = "aced0f0a";             // Odometry data
mapname_prefix = "aced220c";          // Switch maps
map_request_prefix = "aced220f";      // Download a specified map
prefix_after_reloc = "aced0f0b";      // Relocalization

ROS2 service interfaces

Mapping, map switching, map downloading, and relocalization are also available through ROS2 services. A service response of true indicates success; false indicates failure.

Use ros2 service call for the following commands. Map names must not start with a number and must be no longer than 30 characters.

Build a map

Service name: /LxCamera_Mapping_srv Service definition:

bool status      # Start mapping: true; stop mapping: false
string mapname   # Map name; must not start with a number and must be no longer than 30 characters
---
bool result      # true: success; false: failure

Call the service:

ros2 service call /LxCamera_Mapping_srv lx_camera_ros/srv/LxMapping "{
  status: true,
  mapname: 'test_map'
}"

Switch maps

Service name: /LxCamera_SwitchMap_srv Service definition:

string mapname   # Map name; must not start with a number and must be no longer than 30 characters
---
bool result      # true: success; false: failure

Call the service:

ros2 service call /LxCamera_SwitchMap_srv lx_camera_ros/srv/LxSwitchMap "{
  mapname: 'zszs999'
}"

Download a map

Service name: /LxCamera_DownloadMap_srv Service definition:

string mapname    # Map name; must not start with a number and must be no longer than 30 characters
string save_path  # Absolute save path, for example "/home/lx/map"; omit the trailing slash
---
bool result       # true: success; false: failure

Call the service:

ros2 service call /LxCamera_DownloadMap_srv lx_camera_ros/srv/LxDownloadMap "{
  mapname: 'TEST_999',
  save_path: '/home/fr1511b/T/TEST'
}"

Relocalize

Service name: /LxCamera_UploadReloc_srv Service definition:

geometry_msgs/PoseWithCovarianceStamped pose
---
bool result       # true: success; false: failure

Call the service:

ros2 service call /LxCamera_UploadReloc_srv lx_camera_ros/srv/LxUploadReloc "{
  \"pose\": {
    \"header\": {
      \"stamp\": {\"sec\": 0, \"nanosec\": 0},
      \"frame_id\": \"map\"
    },
    \"pose\": {
      \"pose\": {
        \"position\": {\"x\": 4.5, \"y\": -15.5, \"z\": 0.0},
        \"orientation\": {\"x\": 0.0, \"y\": 0.0, \"z\": 0.694658, \"w\": 0.71934}
      },
      \"covariance\": [
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0
      ]
    }
  }
}"

Get the current map name

Service name: /LxCamera_GetCurMapname_srv Service definition:

bool get_cur_mapname # Get the map identifier
---
string mapname      # Current map name

Call the service:

ros2 service call /LxCamera_GetCurMapname_srv lx_camera_ros/srv/LxGetmapname "{
  get_cur_mapname: true
}"

Get the current map list

Service name: /LxCamera_GetMapList_srv Service definition:

bool get_map_list # Get the map list
---
string[] map_list # Map list

Call the service:

ros2 service call /LxCamera_GetMapList_srv lx_camera_ros/srv/LxGetmaplist "{
  get_map_list: true
}"

Exit mapping

Service name: /LxCamera_ExitMapping_srv Service definition:

bool exit_mapping # Exit mapping
---
bool state        # true: success; false: failure

Call the service:

ros2 service call /LxCamera_ExitMapping_srv lx_camera_ros/srv/LxExitMapping "{
  exit_mapping: true
}"

Delete a map

Service name: /LxCamera_EraseMap_srv Service definition:

string mapname    # Map name; must not start with a number and must be no longer than 30 characters
---
bool result       # true: success; false: failure

Call the service:

ros2 service call /LxCamera_EraseMap_srv lx_camera_ros/srv/LxEraseMap "{
  mapname: 'TEST888'
}"

Download a heat map

Service name: /LxCamera_DownloadHeatMap_srv Service definition:

string mapname    # Map name; must not start with a number and must be no longer than 30 characters
string save_path  # Absolute save path, for example "/home/lx/map"; omit the trailing slash
---
bool result       # true: success; false: failure

Call the service:

ros2 service call /LxCamera_DownloadHeatMap_srv lx_camera_ros/srv/LxDownloadMap "{
  mapname: 'TEST_999',
  save_path: '/home/fr1511b/T/TEST'
}"

Incremental mapping

Service name: /LxCamera_IncMapping_srv Service definition:

bool status      # Start mapping: true; stop mapping: false
string mapname   # Map name; must not start with a number and must be no longer than 30 characters
---
bool result

Call the service:

ros2 service call /LxCamera_IncMapping_srv lx_camera_ros/srv/LxMapping "{
  status: true,
  mapname: 'test_map'
}"

Overview

Camera SDK

Camera tools

ROS integration

V2 localization and protocols

V2 ROS2 interface reference

Overview

Compile

Run

ROS2 topic interfaces

Receive localization pose

Receive localization status

Receive camera storage usage

Receive the faulty module name

Receive mapping progress

Receive mapping status

Set parameters

Switch maps

Download a map

Upload odometry

Relocalize

Message type prefixes

ROS2 service interfaces

Build a map

Switch maps

Download a map

Relocalize

Get the current map name

Get the current map list

Exit mapping

Delete a map

Download a heat map

Incremental mapping

​Overview

​Compile

​Run

​ROS2 topic interfaces

​Receive localization pose

​Receive localization status

​Receive camera storage usage

​Receive the faulty module name

​Receive mapping progress

​Receive mapping status

​Set parameters

​Switch maps

​Download a map

​Upload odometry

​Relocalize

​Message type prefixes

​ROS2 service interfaces

​Build a map

​Switch maps

​Download a map

​Relocalize

​Get the current map name

​Get the current map list

​Exit mapping

​Delete a map

​Download a heat map

​Incremental mapping

Overview

Compile

Run

ROS2 topic interfaces

Receive localization pose

Receive localization status

Receive camera storage usage

Receive the faulty module name

Receive mapping progress

Receive mapping status

Set parameters

Switch maps

Download a map

Upload odometry

Relocalize

Message type prefixes

ROS2 service interfaces

Build a map

Switch maps

Download a map

Relocalize

Get the current map name

Get the current map list

Exit mapping

Delete a map

Download a heat map

Incremental mapping