拓展3：FishBot 树莓派配置建图导航

小鱼

@2524167316 检查一下tf_tree

今朝

@小鱼之前发现/odom有话题，但是没有数据传过来，现在/odom有数据了，但是还是建不了图

2216200358

@小鱼在拓展3：FishBot 树莓派配置建图导航中说：

ros2 launch fishbot_bringup fishbot_bringup.launch.py

运行之后，出现以下错误：

打开rviz之后也没有小车模型，也没有RobotModel话题，请问怎么解决。

小鱼

@2216200358 提供下完整日志

https://fishros.org.cn/forum/topic/151/提问前必看-不符合要求的问题拒绝回答

2216200358

@小鱼雷达和四驱板都已经成功运行，运行ros2 launch fishbot_bringup fishbot_bringup.launch.py后，输出如下：

在进行建图操作时，输入ros2 launch slam_toolbox online_async_launch.py，输出如下：

在rviz中没有RobotModel话题：

我是想要加载小车的模型在进行建图。

小鱼

@2216200358 在拓展3：FishBot 树莓派配置建图导航中说：

fishbot_bringup.launch.py

看一下robot-state-publisher节点

2216200358

@小鱼
这样的
这是节点：

小鱼

@小鱼你把这个文件 ishbot_bringup.launch.py 的内容粘贴出来，另外不要截图：

@小鱼在提问前必看！不符合要求的问题拒绝回答！！中说：

不要截图，要复制粘贴，一定要代码块包裹
不要截图的原因是，代码方便回答者去复制帮你搜索，而且无论是在手机上还是电脑上都更容易看。

2216200358

@小鱼

import os
from launch import LaunchDescription
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node
from launch_ros.substitutions import FindPackageShare


def generate_launch_description():
    package_name = 'fishbot_description'
    urdf_name = "fishbot_v1.0.0.urdf"

    ld = LaunchDescription()
    pkg_share = FindPackageShare(package=package_name).find(package_name)
    urdf_model_path = os.path.join(pkg_share, f'urdf/{urdf_name}')

    robot_state_publisher_node = Node(
        package='robot_state_publisher',
        executable='robot_state_publisher',
        arguments=[urdf_model_path]
    )

    joint_state_publisher_node = Node(
        package='joint_state_publisher',
        executable='joint_state_publisher',
        name='joint_state_publisher',
        arguments=[urdf_model_path],
        output='screen',

    )

    fishbot_bringup_node = Node(
        package='fishbot_bringup',
        executable='fishbot_bringup',
        name='fishbot_bringup',
        output='screen',
    )

    ld.add_action(joint_state_publisher_node)
    ld.add_action(robot_state_publisher_node)
    ld.add_action(fishbot_bringup_node)

    return ld

小鱼

@2216200358 在拓展3：FishBot 树莓派配置建图导航中说：

robot_state_publisher_node = Node(
package='robot_state_publisher',
executable='robot_state_publisher',
arguments=[urdf_model_path]
)

这个写的感觉不太对，应该加个参数好像，你看看书前面的代码，或者最近B站的课程，也可以把TF贴出来看看

2216200358

@小鱼 ```
#include <rclcpp/rclcpp.hpp>
#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)
{
RCLCPP_INFO(this->get_logger(), "大家好，我是%s.", name.c_str());
odom_subscribe_ = this->create_subscription<nav_msgs::msg::Odometry>("odom", rclcpp::SensorDataQoS(), std::bind(&TopicSubscribe01::odom_callback, this, std::placeholders::1));
tf_broadcaster = std::make_unique<tf2_ros::TransformBroadcaster>(this);
}

private:
// 声明一个订阅者
rclcpp::Subscription<nav_msgs::msg::Odometry>::SharedPtr odom_subscribe_;
std::unique_ptr<tf2_ros::TransformBroadcaster> tf_broadcaster_;
nav_msgs::msg::Odometry odom_msg_;

void odom_callback(const nav_msgs::msg::Odometry::SharedPtr msg)
{
(void)msg;
RCLCPP_INFO(this->get_logger(), "recv odom->base_footprint tf :(%f,%f)", msg->pose.pose.position.x, msg->pose.pose.position.y);
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:
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;
tf_broadcaster_->sendTransform(transform);

}
};

int main(int argc, char argv)
{
rclcpp::init(argc, argv);
/产生一个的节点/
auto node = std::make_shared<TopicSubscribe01>("fishbot_bringup");
/ 运行节点，并检测退出信号/
rclcpp::WallRate loop_rate(1000.0);
while (rclcpp::ok())
{
rclcpp::spin_some(node);
node->publish_tf();
loop_rate.sleep();
}

rclcpp::shutdown();
return 0;
}

小鱼

@小鱼 tf指的是 rqt-tf-tree 图，可以看看前面基础课程