启动fishbot建图程序后应该从哪里提取定位数据？

小鱼

@siviechen 你可以尝试slam_toolbox ，相比carto更好用。

ros2 launch slam_toolbox online_async_launch.py

砖头

@小鱼我是想自己学写一写slam算法的。cartographer我已经把多少看了一遍了，所以我想了解一些cartographer实现方面的问题，比如上面这些。能教一教吗

小鱼

@siviechen 按照教程应该能跑起来，你遇到什么错误了

砖头

@小鱼 emm，是这样的：教程里是教我们下载carto源码，然后改配置文件.lua和launch文件，然后启动gazebo仿真，然后跑cartographer，这样做是没问题的，我的也没问题。

而我现在是把启动gazebo的仿真这一步换成了启动fishbot实车，启动了agent来获取scan，odom和imu数据。（在这同时把launch文件里的'use_sim_time'改成了’false‘，因为不是在跑仿真了）

然后我放一张rviz的图：

和一张rqt_graph的图：

我对其的理解是map没有数据，用ros2 topic echo去试也是没有数据跳出来的

不知道要如何才能像小鱼的雷达docker选2那样跑起来

小鱼

@siviechen 看一下tf,还有frameid对不对

砖头

@小鱼

ros2 run tf2_tools view_frames

输入了这个命令行，好像没有tf的样子

小鱼

@siviechen 再刷新看看，没有就有大问题了

砖头

@小鱼你这么说我突然紧张起来了

我输入这四条（雷达选1），重试了一下

结果仍然是No tf data received

小鱼

@siviechen 用rqt_tf_tree 看

砖头

@小鱼 ros2好像没有这个功能，rqt_tf_tree: command not found

小鱼

@siviechen 有的，搜一下安装下

砖头

@小鱼找到了，贴一下过程：

sudo apt install ros-humble-rqt-tf-tree
rm ~/.config/ros.org/rqt_gui.ini #删除缓存，不然报错
ros2 run rqt_tf_tree rqt_tf_tree

但是结果还是一样的：

会和车的雷达要把fixed frame改成laser_frame有关系吗？默认好像是map

小鱼

@siviechen 那就真的可能没人发布frame,你可以把这里的做一下

https://fishros.com/d2lros2/#/

砖头

@小鱼行，我试试

砖头

@小鱼我想起来教程里有个fishbot_bringup，我就直接拿来用了。但是虽然有了tf树，算法却还是跑不起起来。过程：

#MicroRos
sudo docker run -it --rm -v /dev:/dev -v /dev/shm:/dev/shm --privileged --net=host microros/micro-ros-agent:$ROS_DISTRO udp4 --port 8888 -v6

#laser
xhost + && sudo docker run  -it --rm  -v /dev:/dev -v /dev/shm:/dev/shm --privileged  -v /tmp/.X11-unix:/tmp/.X11-unix --device /dev/snd -e DISPLAY=unix$DISPLAY -p 8889:8888 registry.cn-hangzhou.aliyuncs.com/fishros/fishbot_laser

#tf
ros2 launch fishbot_bringup fishbot_bringup.launch.py

#carto
ros2 launch fishbot_cartographer cartographer.launch.py 

#显示tf树
ros2 run rqt_tf_tree rqt_tf_tree 

#rqt_graph
rqt_graph

我个人觉得是ros2新增的qos的问题。启动carto后慢慢翻终端里的信息会找到这么两条：

[cartographer_node-1] [WARN] [1692678150.099094890] [cartographer logger]: W0822 12:22:30.000000 11917 tf_bridge.cpp:53] Lookup would require extrapolation into the past.  Requested time 1692678149.889606 but the earliest data is at time 1692678149.949214, when looking up transform from frame [odom] to frame [base_link]


[rviz2-3] [WARN] [1692678150.507302604] [rviz2]: New publisher discovered on topic '/scan', offering incompatible QoS. No messages will be sent to it. Last incompatible policy: RELIABILITY_QOS_POLICY

[ERROR] [cartographer_node-1]: process has died [pid 11917, exit code -6, cmd '/home/cxw/fishbot_ws/install/cartographer_ros/lib/cartographer_ros/cartographer_node -configuration_directory /home/cxw/fishbot/install/fishbot_cartographer/share/fishbot_cartographer/config -configuration_basename fishbot_2d.lua --ros-args -r __node:=cartographer_node --params-file /tmp/launch_params_w6i5hcn_'].

第二条消息是说进程没了，感觉这应该是rqt_graph里连cartographer_node节点都刷不出来的原因？

小鱼大佬的docker雷达按2启动建图不是很顺利吗，能想到是什么原因吗？

小鱼

@siviechen 改一些fishbot_bringup的代码，改成和教程中的一致：

#include <rclcpp/rclcpp.hpp>
#include <nav_msgs/msg/odometry.hpp>
#include <tf2/utils.h>
#include <tf2_ros/transform_broadcaster.h>

class TopicSubscribe01 : public rclcpp::Node
{
public:
  TopicSubscribe01(std::string name) : Node(name)
  {
    // 创建一个订阅者，订阅"odom"话题的nav_msgs::msg::Odometry类型消息
    odom_subscribe_ = this->create_subscription<nav_msgs::msg::Odometry>(
      "odom", rclcpp::SensorDataQoS(),
      std::bind(&TopicSubscribe01::odom_callback, this, std::placeholders::_1));

    // 创建一个tf2_ros::TransformBroadcaster用于广播坐标变换
    tf_broadcaster_ = std::make_unique<tf2_ros::TransformBroadcaster>(this);
  }

private:
  rclcpp::Subscription<nav_msgs::msg::Odometry>::SharedPtr odom_subscribe_;
  std::unique_ptr<tf2_ros::TransformBroadcaster> tf_broadcaster_;
  nav_msgs::msg::Odometry odom_msg_;

  // 回调函数，处理接收到的odom消息
  void odom_callback(const nav_msgs::msg::Odometry::SharedPtr msg)
  {
    (void)msg;
    RCLCPP_INFO(this->get_logger(), "接收到里程计信息->底盘坐标系 tf :(%f,%f)", 
                msg->pose.pose.position.x, msg->pose.pose.position.y);

    // 更新odom_msg_的姿态信息
    odom_msg_.pose.pose.position.x = msg->pose.pose.position.x;
    odom_msg_.pose.pose.position.y = msg->pose.pose.position.y;
    odom_msg_.pose.pose.position.z = msg->pose.pose.position.z;

    odom_msg_.pose.pose.orientation.x = msg->pose.pose.orientation.x;
    odom_msg_.pose.pose.orientation.y = msg->pose.pose.orientation.y;
    odom_msg_.pose.pose.orientation.z = msg->pose.pose.orientation.z;
    odom_msg_.pose.pose.orientation.w = msg->pose.pose.orientation.w;
  };

public:
  // 发布坐标变换信息
  void publish_tf()
  {
    geometry_msgs::msg::TransformStamped transform;
    double seconds = this->now().seconds();
    transform.header.stamp = rclcpp::Time(static_cast<uint64_t>(seconds * 1e9));
    transform.header.frame_id = "odom";
    transform.child_frame_id = "base_footprint";

    transform.transform.translation.x = odom_msg_.pose.pose.position.x;
    transform.transform.translation.y = odom_msg_.pose.pose.position.y;
    transform.transform.translation.z = odom_msg_.pose.pose.position.z;
    transform.transform.rotation.x = odom_msg_.pose.pose.orientation.x;
    transform.transform.rotation.y = odom_msg_.pose.pose.orientation.y;
    transform.transform.rotation.z = odom_msg_.pose.pose.orientation.z;
    transform.transform.rotation.w = odom_msg_.pose.pose.orientation.w;

    // 广播坐标变换信息
    tf_broadcaster_->sendTransform(transform);
  }
};

int main(int argc, char **argv)
{
  // 初始化ROS节点
  rclcpp::init(argc, argv);

  // 创建一个TopicSubscribe01节点
  auto node = std::make_shared<TopicSubscribe01>("fishbot_bringup");

  // 设置循环频率
  rclcpp::WallRate loop_rate(20.0);
  while (rclcpp::ok())
  {
    // 处理回调函数
    rclcpp::spin_some(node);

    // 发布坐标变换信息
    node->publish_tf();

    // 控制循环频率
    loop_rate.sleep();
  }

  // 关闭ROS节点
  rclcpp::shutdown();
  return 0;
}

砖头

@小鱼改完了，有两处不同：

double seconds = this->now().seconds() ; //+ 1.0;   #41行
rclcpp::WallRate loop_rate(20.0); //(1000.0);   #63行

编译+source了。但是结果还是没有改变