1.目的:為了可以標定普通USB相機和固定在相機上的外置IMU的外參,我希望通過ROS獲取更高分辨率和更高頻率的圖像數據,并且可以將圖像和imu的topic發布出來,直接使用rosbag record錄制話題數據,寫入bag文件,這樣獲得的bag文件直接可以用于相機和IMU的外參標定, 標定工具是kalibr.
2. 為了達到上述目的,我首先是完成使用ros發布出來從串口獲取的imu數據,目前獲取的頻率是200hz,也是從網上找到的一個ros中串口通信的小demo,? ? ?參考? ?https://blog.csdn.net/tansir94/article/details/81357612? 和? ?https://blog.csdn.net/xinmei4275/article/details/85040164?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-2.nonecase&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-2.nonecase
3. 我安裝了minicom? 串口小工具
sudo apt-get install minicom
sudo minicom -D /dev/ttyUSB0 -b 230400 -H -w
-D 設置串口
-b 設置波特率
-H 設置十六進制顯示
-w 自動換行
我的代碼如下
#include <ros/ros.h>
#include <sensor_msgs/Imu.h>
#include <serial/serial.h> //ROS已經內置了的串口包
#include <std_msgs/Empty.h>
#include <std_msgs/String.h>
serial::Serial ser; //聲明串口對象sensor_msgs::Imu imu_data;
//回調函數
void write_callback(const std_msgs::String::ConstPtr &msg) {ROS_INFO_STREAM("Writing to serial port" << msg->data);ser.write(msg->data); //發送串口數據
}
int main(int argc, char **argv) {//初始化節點ros::init(argc, argv, "serial_example_node");//聲明節點句柄ros::NodeHandle nh;//訂閱主題,并配置回調函數ros::Subscriber write_sub = nh.subscribe("write", 1000, write_callback);//發布主題ros::Publisher read_pub = nh.advertise<std_msgs::String>("read", 1000);ros::Publisher IMU_read_pub =nh.advertise<sensor_msgs::Imu>("imu_data", 1000);// ros::Publisher Image_read_pub =
// nh.advertise<sensor_msgs::>("imu_data", 1000);try {//設置串口屬性,并打開串口ser.setPort("/dev/ttyUSB0");ser.setBaudrate(230400);serial::Timeout to = serial::Timeout::simpleTimeout(1000);ser.setTimeout(to);ser.open();} catch (serial::IOException &e) {ROS_ERROR_STREAM("Unable to open port ");return -1;}//檢測串口是否已經打開,并給出提示信息if (ser.isOpen()) {ROS_INFO_STREAM("Serial Port initialized");} else {return -1;}//指定循環的頻率ros::Rate loop_rate(400);while (ros::ok()) {unsigned char data_size;/*! Return the number of characters in the buffer. */// available()
// while((data_size = ser.available()) < 11){// } if (data_size = ser.available()){unsigned char tmpdata[data_size];ser.read(tmpdata, data_size);// std::cout << "data_size: " << data_size << std::endl;for (int i = 0; i < data_size; i++) {if (tmpdata[i] == 0x55) {switch (tmpdata[i + 1]) {case 0x51:imu_data.header.stamp = ros::Time::now();imu_data.header.frame_id = "base_link";imu_data.linear_acceleration.x =((short)(tmpdata[3 + i] << 8 | tmpdata[2 + i])) / 32768.0 * 4 * 9.7803;imu_data.linear_acceleration.y =((short)(tmpdata[5 + i] << 8 | tmpdata[4 + i])) / 32768.0 * 4 * 9.7803;imu_data.linear_acceleration.z =((short)(tmpdata[7 + i] << 8 | tmpdata[6 + i])) / 32768.0 * 4 * 9.7803;std::cout<<"acc: "<<std::setprecision(16)<<imu_data.header.stamp<<" " <<imu_data.linear_acceleration.x<<" "<<imu_data.linear_acceleration.y<<" "<<imu_data.linear_acceleration.z<<std::endl<<std::endl;break;case 0x52:imu_data.angular_velocity.x =((short)(tmpdata[3 + i] << 8 | tmpdata[2 + i])) / 32768.0 * 500;imu_data.angular_velocity.y =((short)(tmpdata[5 + i] << 8 | tmpdata[4 + i])) / 32768.0 * 500;imu_data.angular_velocity.z =((short)(tmpdata[7 + i] << 8 | tmpdata[6 + i])) / 32768.0 * 500;//ROS_INFO_STREAM("imu_data: " << imu_data);IMU_read_pub.publish(imu_data);std::cout<<"gyr: "<<std::setprecision(16)<<imu_data.header.stamp<<" "<<imu_data.angular_velocity.x <<" "<<imu_data.angular_velocity.y <<" "<<imu_data.angular_velocity.z <<std::endl;break; }}}}// if (ser.available()) {// // ROS_INFO_STREAM("Reading from serial port\n");// //讀到的是string類型的,// std_msgs::String result;// result.data = ser.read(ser.available());// ROS_INFO_STREAM("Read: " << result.data);// std::cout << "result.data: " << result.data << std::endl <<// std::endl;// // read_pub.publish(result);// }//處理ROS的信息,比如訂閱消息,并調用回調函數ros::spinOnce();loop_rate.sleep();}
}
CMakeLists.txt的內容
cmake_minimum_required(VERSION 2.8.3)
project(serialPort)find_package(catkin REQUIRED COMPONENTSroscppserialstd_msgs
)catkin_package(
# INCLUDE_DIRS include
# LIBRARIES serialPortCATKIN_DEPENDS roscpp serial std_msgs
# 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}
)add_executable(serialPort src/serialPort.cpp)add_dependencies(serialPort ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})target_link_libraries(serialPort${catkin_LIBRARIES}
)
4. 獲取uvc相機的圖像
#include <cv_bridge/cv_bridge.h>
#include <image_transport/image_transport.h>
#include <iostream>
#include <opencv2/highgui/highgui.hpp>
#include <ros/ros.h>
#include <sensor_msgs/Image.h>
#include <stdio.h>
using namespace cv;int main(int argc, char **argv) {ros::init(argc, argv, "image_publisher");ros::NodeHandle nh;image_transport::ImageTransport it(nh);image_transport::Publisher pub0 = it.advertise("camera/left", 0);image_transport::Publisher pub1 = it.advertise("camera/right", 1);//測試出來我的小覓相機是單ID相機cv::VideoCapture cap(0);cap.set(CV_CAP_PROP_FRAME_WIDTH, 2560);cap.set(CV_CAP_PROP_FRAME_HEIGHT, 720);cap.set(CV_CAP_PROP_FPS, 60);// cap.set(CV_CAP_PROP_FRAME_WIDTH, 1280);// cap.set(CV_CAP_PROP_FRAME_HEIGHT, 480);// cap.set(CV_CAP_PROP_FPS, 60);if (!cap.isOpened()) {ROS_INFO("cannot open video device0\n");return -1;}cv::Mat frame, frame_G, frame_L, frame_R;sensor_msgs::ImagePtr msg0;sensor_msgs::ImagePtr msg1;sensor_msgs::ImagePtr msg;ros::Rate loop_rate(30);while (nh.ok()) {cap >> frame;ros::Time time_now = ros::Time::now();cv::cvtColor(frame, frame_G, cv::COLOR_BGR2GRAY);frame_L = frame_G(cv::Rect(0, 0, 1280, 720));frame_R = frame_G(cv::Rect(1280, 0, 1280, 720));// frame_L = frame_G(cv::Rect(0, 0, 640, 480));// frame_R = frame_G(cv::Rect(640, 0, 640, 480));// cv::imshow("frame_L", frame_L);// cv::waitKey(2);// cv::imshow("frame_R", frame_R);// cv::waitKey(2);// cv::imshow("frame", frame);// cv::waitKey(2);// cv::imshow("frame_G", frame_G);// cv::waitKey(2);if (!frame_L.empty()) {msg0 =cv_bridge::CvImage(std_msgs::Header(), "mono8", frame_L).toImageMsg();msg0->header.stamp = time_now;pub0.publish(msg0);}if (!frame_R.empty()) {msg1 =cv_bridge::CvImage(std_msgs::Header(), "mono8", frame_R).toImageMsg();msg1->header.stamp = time_now;pub1.publish(msg1);}ROS_INFO("Publishing camera/left camera/right ROS topic MSG!! ");ros::spinOnce();loop_rate.sleep();}
}
CMakeLists.txt文件內容如下
cmake_minimum_required(VERSION 2.8.3)
project(imgReader)find_package(catkin REQUIRED COMPONENTSsensor_msgscv_bridgeroscppstd_msgsimage_transport
)
find_package(OpenCV REQUIRED)#
catkin_package(
# INCLUDE_DIRS include
# LIBRARIES imgReaderCATKIN_DEPENDS sensor_msgs cv_bridge roscpp std_msgs image_transport
# DEPENDS system_lib
)###########
## Build ##
############# Specify additional locations of header files
## Your package locations should be listed before other locationsinclude_directories(
# include${catkin_INCLUDE_DIRS}${OpenCV_INCLUDE_DIRS}
)add_executable(imgReader src/imgReader.cpp)target_link_libraries(imgReader${catkin_LIBRARIES}${OpenCV_LIBRARIES}
)
add_dependencies(imgReader ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
5. 設置rviz顯示圖像和Imu數據
首先設置launch文件
<launch><node pkg="serialPort" type="serialPort" name="serialPort" required="true" output="screen"><param name="port" value="/dev/ttyUSB0"/></node><node pkg="imgReader" type="imgReader" name="imgReader" required="true" output="screen"><param name="port" value="/dev/video0"/></node><!-- 在rviz中顯示-->
<node name="rviz" pkg="rviz" type="rviz" args="-d $(find imgReader)/config/rviz/get_imu_image.rviz" required="true" /></launch>
如果不設置launch文件,也可以分別發布兩個節點的信息.
terminal 1
roscoreterminal 2
source ./devel/setup.bash
rosrun serialPort serialPortterminal 3
source ./devel/setup.bash
rosrun imgReader imgReader
參考這篇文章設置rviz的配置文件??https://blog.csdn.net/weixin_44684139/article/details/104416690?和?https://blog.csdn.net/xinmei4275/article/details/85040164?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-2.nonecase&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-2.nonecase
首先是運行你的node,使得圖像和imu數據的topics都發布出來,使用rostopic list查看當前正在發布的topic
然后打開rviz窗口界面
rosrun rviz rviz
然后添加Imu和image的topics
最后保存rviz配置到相應的路徑.然后在上面的launch文件最后加上rviz配置文件,這樣,當roslaunch launch文件時,就可以同時加載rviz視圖窗口了.
就像下圖這樣.
?