rosbag相关

使用rosbag录制数据的功能将txt转成bag

将txt文件读出来并发布到topic上，
比如：读取imu数据，发布到topic /imu_info上

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
// #include 
using namespace std;


ros::Time timesamp2rostime(int64_t timesamp){
     
  std::string suanz = std::to_string(timesamp);
  std::string sec_string = suanz.substr(0,10);
  std::string nsec_string = suanz.substr(10,9);
  while(nsec_string.length() < 9){
     
      nsec_string += "0";
  }
  return ros::Time(std::stoi(sec_string),std::stoi(nsec_string));
}

string replace(string original, char o, char n){
     
  string res = original;
  for(int i = 0; i < res.length(); i ++){
     
    if(res[i] == o)res[i] = n;
  }
  return res;
}


int main(int argc, char **argv){
     
  ros::init(argc, argv, "talker2");
  ros::NodeHandle nh;

  sensor_msgs::Imu msg;


  ros::Publisher pub = nh.advertise<sensor_msgs::Imu>("imu_info", 1);   
  ros::Rate loop_rate(200);
  // while(1){
     
  //   if(_kbhit()){
     
  //     int ch = _getch();
  //     if(ch == 27){
     
  //       break;
  //     }
  //   }
  // }
  // bool ros::Duration::sleep();
  ros::Duration(5).sleep(); // sleep for half a second
  vector<sensor_msgs::Imu> imu_vector;
  // for(int i = 0; i < 3; i ++){
     
  //   msg.header.stamp = static_cast(1234);
  //   msg.angular_velocity.x = 10;
  //   msg.angular_velocity.y = 12;
  //   msg.angular_velocity.z = i;
  //   imu_vector.push_back(msg);
  // }
  string pathname = "/home/efan/Downloads/imu_raw.txt";
  ifstream infile;
	infile.open(pathname.data()); 
	assert(infile.is_open()); 
  string pre_s = "";
	string s;
	while (getline(infile, s)) {
     
    if(s[0] == '#')continue;
    if(s == pre_s)continue;
    pre_s = s;
    s = replace(s,',',' ');
    
		istringstream is(s);
    sensor_msgs::Imu suanz;
    int64_t time_imu;
    // cout << s << endl;
    s.clear();
    is >> time_imu;
    // ros::Time begin = ros::Time::now();
    // cout << begin.sec << " "<
    is >> suanz.linear_acceleration.x;
    is >> suanz.linear_acceleration.y;
    is >> suanz.linear_acceleration.z;
    is >> suanz.angular_velocity.x;
    is >> suanz.angular_velocity.y;
    is >> suanz.angular_velocity.z;
    suanz.header.stamp = timesamp2rostime(time_imu);
    msg = suanz;
    ROS_INFO_STREAM(msg);
    pub.publish(msg);
    loop_rate.sleep();
		
	}
	infile.close();
  return 0;
}

之后运行该节点后运行下述代码即可将固定topics的数据录制到filename.bag中

rosrun rosbag record -O filename.bag topic-names
# or rosrun all topic that includes "info"
rosrun rosbag record -O imu_Rpose.bag -e "(.*)info(.*)"

而且必须先运行起topic-names所在的节点后，运行上述代码才有效，因此在具体的读取txt的代码中设置暂停时间

详细代码见https://github.com/Efanplus/make_bag_from_txt

注：rosbag 可以支持自动排序，即不同sensor的数据录制后，其可以根据自带的time排序，存储起来
有时没有进行指针close,会导致bag的index有问题而不可用，可使用reindex修正

rosbag reindex name.bag

rosbag $\to$ txt

使用指令将rosbag转换为txt, 如：将imu_info 的数据转为t,后缀名自定，　第一行会以＇％＇为首给出各列含义

rostopic echo -b imu_encoder.bag -p /imu_info >t

挑选出rosbag中某些topic或者满足某些条件的数据

利用　rosbag

rosbag filter input.bag output.bag 'topic == "/camera/image_raw/compressed" or topic == "/scan" or topic == "/timetag" or  topic == "/tf" and m.transforms[0].header.frame_id != "/odom" and m.transforms[0].child_frame_id != "/odom"'

merge two rosbag into one

使用第三方文本bag_merge.py github地址

bag_merge.py --help
usage: bagmerge.py [-h] [-o output_file] [-t topics] [-i] main_bagfile bagfile

Merges two bagfiles.

positional arguments:
  main_bagfile    path to a bagfile, which will be the main bagfile
  bagfile         path to a bagfile which should be merged to the main bagfile

optional arguments:
  -h, --help      show this help message and exit
  -o output_file  name of the output file
  -t topics       topics which should be merged to the main bag
  -i              reindex bagfile