ROS2 Foxy中正确引入Eigen3：解决头文件路径异常问题

问题背景 #

我在ROS2 Foxy工作空间开发C++程序，想使用Eigen3库。已经按照官方cmake模块的步骤修改了CMakeLists.txt和package.xml，但代码中引入头文件时，系统只识别我在根目录手动克隆的Eigen3路径，不知道怎么通过ROS2的依赖管理正确引入。

我的CMakeLists.txt #

cmake_minimum_required(VERSION 3.5)
project(tachimawari)

if(NOT CMAKE_C_STANDARD)
  set(CMAKE_C_STANDARD 99)
endif()

if(NOT CMAKE_CXX_STANDARD)
  set(CMAKE_CXX_STANDARD 17)
endif()

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic -fPIC)
endif()

find_package(ament_cmake REQUIRED)
find_package(dynamixel_sdk REQUIRED)
find_package(kansei_interfaces REQUIRED)
find_package(keisan REQUIRED)
find_package(rclcpp REQUIRED)
find_package(tachimawari_interfaces REQUIRED)
find_package(eigen3_cmake_module REQUIRED)
find_package(Eigen3 REQUIRED)

add_library(${PROJECT_NAME} SHARED
  "src/${PROJECT_NAME}/control/controller/module/cm740.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/instruction/bulk_read_packet.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/instruction/read_packet.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/instruction/sync_write_packet.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/instruction/write_packet.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/model/packet.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/status/bulk_read_data.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/status/status_packet.cpp"
  "src/${PROJECT_NAME}/control/controller/packet/protocol_1/utils/word.cpp"
  "src/${PROJECT_NAME}/control/controller/platform/linux.cpp"
  "src/${PROJECT_NAME}/control/controller/utils/timer.cpp"
  "src/${PROJECT_NAME}/control/manager/control_manager.cpp"
  "src/${PROJECT_NAME}/control/sdk/module/dynamixel_sdk.cpp"
  "src/${PROJECT_NAME}/control/sdk/packet/model/group_bulk_read.cpp"
  "src/${PROJECT_NAME}/control/sdk/packet/protocol_1/group_bulk_read.cpp"
  "src/${PROJECT_NAME}/control/sdk/packet/protocol_1/group_sync_write.cpp"
  "src/${PROJECT_NAME}/control/sdk/packet/protocol_2/group_bulk_read.cpp"
  "src/${PROJECT_NAME}/control/sdk/packet/protocol_2/group_sync_write.cpp"
  "src/${PROJECT_NAME}/imu/node/imu_node.cpp"
  "src/${PROJECT_NAME}/imu/node/imu_provider.cpp"
  "src/${PROJECT_NAME}/joint/model/joint_id.cpp"
  "src/${PROJECT_NAME}/joint/model/joint.cpp"
  "src/${PROJECT_NAME}/joint/node/joint_manager.cpp"
  "src/${PROJECT_NAME}/joint/node/joint_node.cpp"
  "src/${PROJECT_NAME}/joint/utils/middleware.cpp"
  "src/${PROJECT_NAME}/joint/utils/node_control.cpp"
  "src/${PROJECT_NAME}/node/tachimawari_node.cpp")

target_include_directories(${PROJECT_NAME} PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)

ament_target_dependencies(${PROJECT_NAME}
  dynamixel_sdk
  kansei_interfaces
  keisan
  rclcpp
  tachimawari_interfaces
  Eigen3)

install(DIRECTORY "include" DESTINATION ".")

install(TARGETS ${PROJECT_NAME}
  EXPORT export_${PROJECT_NAME}
  ARCHIVE DESTINATION "lib"
  LIBRARY DESTINATION "lib"
  RUNTIME DESTINATION "bin")

add_executable(check_joints "src/check_joints_main.cpp")
target_include_directories(check_joints PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)
target_link_libraries(check_joints ${PROJECT_NAME})

add_executable(init_joints "src/init_joints_main.cpp")
target_include_directories(init_joints PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)
target_link_libraries(init_joints ${PROJECT_NAME})

add_executable(main "src/tachimawari_main.cpp")
target_include_directories(main PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)
target_link_libraries(main ${PROJECT_NAME})

add_executable(read_buttons "src/read_buttons_main.cpp")
target_include_directories(read_buttons PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)
target_link_libraries(read_buttons ${PROJECT_NAME})

add_executable(read_joints "src/read_joints_main.cpp")
target_include_directories(read_joints PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)
target_link_libraries(read_joints ${PROJECT_NAME})

add_executable(forward_kinematic "src/tachimawari/node/forward_kinematic.cpp")
target_include_directories(forward_kinematic PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)
target_link_libraries(forward_kinematic ${PROJECT_NAME})

install(TARGETS
  check_joints
  init_joints
  main
  read_buttons
  read_joints
  forward_kinematic
  DESTINATION lib/${PROJECT_NAME})

if(BUILD_TESTING)
  find_package(ament_cmake_gtest REQUIRED)
  find_package(ament_lint_auto REQUIRED)

  ament_add_gtest(${PROJECT_NAME}_tests
  "test/joint/joint_test.cpp")

  target_include_directories(${PROJECT_NAME}_tests PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  $<INSTALL_INTERFACE:include>)

  target_link_libraries(${PROJECT_NAME}_tests ${PROJECT_NAME})
  ament_lint_auto_find_test_dependencies()

endif()

ament_export_dependencies(
  dynamixel_sdk
  kansei_interfaces
  keisan
  rclcpp
  tachimawari_interfaces
  Eigen3
  eigen3_cmake_module)
ament_export_include_directories("include")
ament_export_libraries(${PROJECT_NAME})
ament_package()

待修改的C++代码 #

#include <iostream>
#include <stdio.h>
#include <eigen3/Dense> // 这里不知道怎么正确引入
using namespace std;
using namespace Eigen;

typedef Matrix<double, 4, 4> Matrix4D;
typedef Matrix<double, 4, 1> Vector4D;
typedef Matrix<double, 3, 1> Vector3D;

解决步骤 #

1. 确认package.xml依赖配置 #

先检查package.xml是否添加了Eigen相关依赖，没有的话补上：

<depend>eigen3_cmake_module</depend>
<depend>Eigen3</depend>

2. 移除手动克隆的Eigen3 #

删除工作空间根目录下手动克隆的Eigen3文件夹，避免干扰ROS2的依赖查找逻辑。

3. 修改代码中的头文件引入方式 #

通过ROS2的依赖管理配置后，Eigen的根目录已经被添加到编译器的包含路径中，直接用以下方式引入即可：

#include <Eigen/Dense>

不需要加eigen3前缀，因为Eigen3包会自动把包含Eigen文件夹的路径注入到编译环境里。

4. 清理并重新构建 #

执行以下命令彻底清理旧构建文件，重新编译：

rm -rf build install log
colcon build --packages-select tachimawari
source install/setup.bash

完成以上步骤后，编译器就会使用ROS2依赖管理找到的系统Eigen3库，不再依赖手动克隆的版本。

内容的提问来源于stack exchange，提问作者Kuuhaku