ROS相机雷达数据采集并提取

一、采集数据

1、开车

开启底盘电源，松开急停

开启电池电源，分流电源，工控机开关

链接键盘，显示器，鼠标

2、开驱动

（以工控机为例，使用前都需要source）

水星相机驱动：roslaunch galaxy_camera ME3-132GC_xxx.launch

RS16线激光雷达驱动：roslaunch rslidar_sdk start.launch

rosbag record /话题 /话题

查看录包信息前，需要把雷达和相机的网线拔掉，以免冲突。

二、数据处理

1、提取雷达和相机

包位于/media/xxx/Elements/Data/Reality/save_camera_lidar/src/save_camera_lidar

话题名称查看rostopic list：

/clock

/galaxy_camera/image_raw

/rosout

/rosout_agg

/rslidar_points_16

类型查看：rostopic info /

相机与雷达外参：

RT.at<double>(0,0) = -0.064550; RT.at<double>(0,1) = -0.997901; RT.at<double>(0,2) = -0.005232; RT.at<double>(0,3) = 0.452897;

RT.at<double>(1,0) = 0.027399; RT.at<double>(1,1) = 0.003468; RT.at<double>(1,2) = -0.999619; RT.at<double>(1,3) = -9.681164;

RT.at<double>(2,0) = 0.997538; RT.at<double>(2,1) = -0.064669; RT.at<double>(2,2) = 0.027118; RT.at<double>(2,3) = -2.978566;

RT.at<double>(3,0) = 0.0; RT.at<double>(3,1) = 0.0; RT.at<double>(3,2) = 0.0; RT.at<double>(3,3) = 1.0;

相机内参：

P_rect_00.at<double>(0,0) = 1697.098875; P_rect_00.at<double>(0,1) = 0.810076; P_rect_00.at<double>(0,2) = 1205.070736; P_rect_00.at<double>(0,3) = 0.000000e+00;

P_rect_00.at<double>(1,0) = 0.000000e+00; P_rect_00.at<double>(1,1) = 1701.757828; P_rect_00.at<double>(1,2) = 991.242630; P_rect_00.at<double>(1,3) = 0.000000e+00;

P_rect_00.at<double>(2,0) = 0.000000e+00; P_rect_00.at<double>(2,1) = 0.000000e+00; P_rect_00.at<double>(2,2) = 1.000000e+00; P_rect_00.at<double>(2,3) = 0.000000e+00;

2、程序运行

bag位于Data/Reality

方法1

（Data/Reality/save_camera_lidar）：源程序不动，修改bag路径和截取图像的时机，改成一接到图片就同时保存雷达点云和图片。

但是这样处理，掉帧爆炸。

方法2：

直接用自带程序提取：

执行$ rosrun image_view extract_images _sec_per_frame:=0.05 image:=/stereo/left/image_raw# <IMAGETOPICINBAGFILE>为bag文件中储存图片的topic

$ rosbag play <BAGFILE> # <BAGFILE>为bag文件的路径

然后就成功保存为jpg，mogrify -format png *.jpg转化成Png

雷达保存：

rosrun pcl_ros bag_to_pcd ulnc-ex.bag \lidar_cloud_calibrated lidar

这种保存方式图片掉很多帧。

方法3

利用参考程序提取https://www.it610.com/article/1291575475952492544.htm

报错ImportError: dynamic module does not define module export function (PyInit_cv_bridge_boost)

这里是因为cv_bridge只能在python2运行，必须要使用python2 xxx来运行。

然后就可以保存png结尾的数据。

方法3成功，程序位于media\Data\Reality\321\raw

 

附录：

PYTHON提取ROSBAG数据代码，需要在python2下运行

save_rosbag.py

 

# coding:utf-8
#!/usr/bin/python
 
# Extract images from a bag file.
 
#PKG = 'beginner_tutorials'
import roslib;   #roslib.load_manifest(PKG)
import rosbag
import rospy
import os
from sensor_msgs.msg import Image
from cv_bridge import CvBridge
from cv_bridge import CvBridgeError
import sys
sys.path.remove('/opt/ros/kinetic/lib/python2.7/dist-packages')
import cv2
 
# Reading bag filename from command line or roslaunch parameter.
#import os
#import sys
 
rgb_path = './image_0/'
laser_path= './lidar'
 
class ImageCreator():
    def __init__(self):
        self.bridge = CvBridge()
        with rosbag.Bag('energy.bag', 'r') as bag:  #要读取的bag文件；
            for topic,msg,t in bag.read_messages():
                if topic == "/galaxy_camera/image_raw": #图像的topic；
                        try:
                            cv_image = self.bridge.imgmsg_to_cv2(msg,"bgr8")
                        except CvBridgeError as e:
                            print(e)
                        timestr = "%.6f" %  msg.header.stamp.to_sec()
                        #%.6f表示小数点后带有6位，可根据精确度须要修改；
                        image_name = timestr+ ".png" #图像命名：时间戳.png
                        cv2.imwrite(rgb_path + image_name, cv_image)  #保存；
                elif topic == "/rslidar_points_16": #laser的topic；
                        timestr = "%.6f" %  msg.header.stamp.to_sec()
                        laser_data_name = timestr + ".txt"
                        laser_data_path = os.path.join(laser_path, laser_data_name)
                        with open(laser_data_path, "w") as f:
                            f.write(str(msg))

if __name__ == '__main__':
    try:
        image_creator = ImageCreator()
    except rospy.ROSInterruptException:
        pass