ROS学习笔记（13）-- IMU in ROS

目录

1. IMU简介

2. ROS IMU msgs

3. 创建IMU消息发布节点node

4. 小结

---

1. IMU简介

      请移步本人的另一篇博客文章，详细介绍了IMU工作原理和卡尔曼滤波方法：https://blog.csdn.net/hhaowang/article/details/88846468

2. ROS IMU msgs

官方文档：http://docs.ros.org/api/sensor_msgs/html/msg/Imu.html

IMU 消息类型为ROS中的一种标准传感器消息类型，其定义已经包含在sensor_msgs/Imu.msg文件夹中。在发布IM消息时需要将该消息类型的头文件包含在内。

消息详细描述如下：

# This is a message to hold data from an IMU (Inertial Measurement Unit)
#
# Accelerations should be in m/s^2 (not in g's), and rotational velocity should be in rad/sec
#
# If the covariance of the measurement is known, it should be filled in (if all you know is the 
# variance of each measurement, e.g. from the datasheet, just put those along the diagonal)
# A covariance matrix of all zeros will be interpreted as "covariance unknown", and to use the
# data a covariance will have to be assumed or gotten from some other source
#
# If you have no estimate for one of the data elements (e.g. your IMU doesn't produce an orientation 
# estimate), please set element 0 of the associated covariance matrix to -1
# If you are interpreting this message, please check for a value of -1 in the first element of each 
# covariance matrix, and disregard the associated estimate.

Header header

geometry_msgs/Quaternion orientation
float64[9] orientation_covariance # Row major about x, y, z axes

geometry_msgs/Vector3 angular_velocity
float64[9] angular_velocity_covariance # Row major about x, y, z axes

geometry_msgs/Vector3 linear_acceleration
float64[9] linear_acceleration_covariance # Row major x, y z 

3. 创建IMU消息发布节点node

【1】实现了串口IMU数据采集和发布，https://blog.csdn.net/jc15988821760/article/details/102581213

【2】采用rostools，对IMU数据进行滤波处理，https://blog.csdn.net/learning_tortosie/article/details/103189118

【3】发布IMU和GPS消息，https://blog.csdn.net/Tansir94/article/details/81385812

【4】实现了串口接收IMU数据，https://blog.csdn.net/xinmei4275/article/details/85040164?depth_1-utm_source=distribute.pc_relevant.none-task&utm_source=distribute.pc_relevant.none-task

#include 
#include "sensor_msgs/Imu.h"
#include 
#include 



/**
 * This tutorial demonstrates simple sending of messages over the ROS system.
 */

//回调函数 
void imu_callback(const sensor_msgs::Imu::ConstPtr& imu_raw) 
{ 
    ROS_INFO_STREAM("Imu raw data publish working : "<header.stamp); 
	ROS_INFO_STREAM("Data samples orientation: " <orientation); 
     
} 

int main(int argc, char *argv[])
{

	ros::init(argc, argv, "imu_raw_pub"); // node 

	/**
	 * NodeHandle is the main access point to communications with the ROS system.
	 * The first NodeHandle constructed will fully initialize this node, and the last
	 * NodeHandle destructed will close down the node.
	 */
	ros::NodeHandle n;

	/**
	 * The advertise() function is how you tell ROS that you want to
	 * publish on a given topic name. This invokes a call to the ROS
	 * master node, which keeps a registry of who is publishing and who
	 * is subscribing. After this advertise() call is made, the master
	 * node will notify anyone who is trying to subscribe to this topic name,
	 * and they will in turn negotiate a peer-to-peer connection with this
	 * node.  advertise() returns a Publisher object which allows you to
	 * publish messages on that topic through a call to publish().  Once
	 * all copies of the returned Publisher object are destroyed, the topic
	 * will be automatically unadvertised.
	 *
	 * The second parameter to advertise() is the size of the message queue
	 * used for publishing messages.  If messages are published more quickly
	 * than we can send them, the number here specifies how many messages to
	 * buffer up before throwing some away.
	 */
	ros::Publisher imu_raw_pub = n.advertise("imu_data", 10, imu_callback);
	// topic name -- imu_data

	ros::Rate loop_rate(1);

	while(ros::ok())
    {

		sensor_msgs::Imu imu_raw; // sensor messages - named imu_raw 
		imu_raw.header.stamp = ros::Time::now();
		imu_raw.header.frame_id = "imu_link";
		//四元数位姿,所有数据设为固定值，可以自己写代码获取ＩＭＵ的数据，，然后进行传递
		imu_raw.orientation.x = 0;
		imu_raw.orientation.y = -1;
		imu_raw.orientation.z = -5;
		imu_raw.orientation.w = 6;
		//线加速度
		imu_raw.linear_acceleration.x = 0.01; 
		imu_raw.linear_acceleration.y = 0.02;
		imu_raw.linear_acceleration.z = 0.03;
	//角速度
		imu_raw.angular_velocity.x = 0.05; 
		imu_raw.angular_velocity.y = 0.06; 
		imu_raw.angular_velocity.z = 0.07;


		imu_raw_pub.publish(imu_raw); //imu_raw_pub 节点发布消息至imu_data topic
  
    }
	ros::spinOnce();  
    loop_rate.sleep();

    return 0;
}

修改CMakeLists.txt文件：

cmake_minimum_required(VERSION 2.8.3)
project(imu_raw_pub)

## Compile as C++11, supported in ROS Kinetic and newer
# add_compile_options(-std=c++11)

## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
    roscpp
    std_msgs
    sensor_msgs
    tf)

## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)


## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()

################################################
## Declare ROS messages, services and actions ##
################################################

## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
##   * add a build_depend tag for "message_generation"
##   * add a build_depend and a exec_depend tag for each package in MSG_DEP_SET
##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
##     but can be declared for certainty nonetheless:
##     * add a exec_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
##   * add "message_generation" and every package in MSG_DEP_SET to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * add "message_runtime" and every package in MSG_DEP_SET to
##     catkin_package(CATKIN_DEPENDS ...)
##   * uncomment the add_*_files sections below as needed
##     and list every .msg/.srv/.action file to be processed
##   * uncomment the generate_messages entry below
##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)

## Generate messages in the 'msg' folder
# add_message_files(
#   FILES
#   Message1.msg
#   Message2.msg
# )

## Generate services in the 'srv' folder
# add_service_files(
#   FILES
#   Service1.srv
#   Service2.srv
# )

## Generate actions in the 'action' folder
# add_action_files(
#   FILES
#   Action1.action
#   Action2.action
# )

## Generate added messages and services with any dependencies listed here
# generate_messages(
#   DEPENDENCIES
#   std_msgs  # Or other packages containing msgs
# )

################################################
## Declare ROS dynamic reconfigure parameters ##
################################################

## To declare and build dynamic reconfigure parameters within this
## package, follow these steps:
## * In the file package.xml:
##   * add a build_depend and a exec_depend tag for "dynamic_reconfigure"
## * In this file (CMakeLists.txt):
##   * add "dynamic_reconfigure" to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * uncomment the "generate_dynamic_reconfigure_options" section below
##     and list every .cfg file to be processed

## Generate dynamic reconfigure parameters in the 'cfg' folder
# generate_dynamic_reconfigure_options(
#   cfg/DynReconf1.cfg
#   cfg/DynReconf2.cfg
# )

###################################
## catkin specific configuration ##
###################################
## The catkin_package macro generates cmake config files for your package
## Declare things to be passed to dependent projects
## INCLUDE_DIRS: uncomment this if your package contains header files
## LIBRARIES: libraries you create in this project that dependent projects also need
## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
  # INCLUDE_DIRS include
# LIBRARIES imu_raw_pub
#  CATKIN_DEPENDS other_catkin_pkg
#  DEPENDS system_lib
)

###########
## Build ##
###########

## Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
include
${catkin_INCLUDE_DIRS}
)

## Declare a C++ library
# add_library(${PROJECT_NAME}
#   src/${PROJECT_NAME}/imu_raw_pub.cpp
# )

## Add cmake target dependencies of the library
## as an example, code may need to be generated before libraries
## either from message generation or dynamic reconfigure
# add_dependencies(${PROJECT_NAME} ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})

## Declare a C++ executable
## With catkin_make all packages are built within a single CMake context
## The recommended prefix ensures that target names across packages don't collide
add_executable(imu_raw_pub src/imu_raw_pub.cpp)

## Rename C++ executable without prefix
## The above recommended prefix causes long target names, the following renames the
## target back to the shorter version for ease of user use
## e.g. "rosrun someones_pkg node" instead of "rosrun someones_pkg someones_pkg_node"
# set_target_properties(${PROJECT_NAME}_node PROPERTIES OUTPUT_NAME node PREFIX "")

## Add cmake target dependencies of the executable
## same as for the library above
# add_dependencies(${PROJECT_NAME}_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})

## Specify libraries to link a library or executable target against
target_link_libraries(imu_raw_pub
  ${catkin_LIBRARIES}
)

#############
## Install ##
#############

# all install targets should use catkin DESTINATION variables
# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html

## Mark executable scripts (Python etc.) for installation
## in contrast to setup.py, you can choose the destination
# install(PROGRAMS
#   scripts/my_python_script
#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )

## Mark executables for installation
## See http://docs.ros.org/melodic/api/catkin/html/howto/format1/building_executables.html
# install(TARGETS ${PROJECT_NAME}_node
#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )

## Mark libraries for installation
## See http://docs.ros.org/melodic/api/catkin/html/howto/format1/building_libraries.html
# install(TARGETS ${PROJECT_NAME}
#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   RUNTIME DESTINATION ${CATKIN_GLOBAL_BIN_DESTINATION}
# )

## Mark cpp header files for installation
# install(DIRECTORY include/${PROJECT_NAME}/
#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
#   FILES_MATCHING PATTERN "*.h"
#   PATTERN ".svn" EXCLUDE
# )

## Mark other files for installation (e.g. launch and bag files, etc.)
# install(FILES
#   # myfile1
#   # myfile2
#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
# )

#############
## Testing ##
#############

## Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_imu_raw_pub.cpp)
# if(TARGET ${PROJECT_NAME}-test)
#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()

## Add folders to be run by python nosetests
# catkin_add_nosetests(test)

修改package.xml描述文件：

  imu_raw_pub
  0.0.0
  The imu_raw_pub package

  
  
  
  haowang


  
  
  
  BSD


  
  
  
  


  
  
  
  


  
  
  
  
  

  
  
  
  
  
  
  
  
  
  
  
  
  
  catkin

  roscpp 
  sensor_msgs
  std_msgs

  roscpp
  sensor_msgs
  std_msgs
  

  
  
    

  

---

运行结果：

查看topic和node信息

4. 小结

简单的IMU消息类型的发布测试，下一节试验串口接收IMU数据并发布至imu_data topic中去。