ros 使用C++发布动态坐标变换

在ROS中，可以使用tf2库来发布动态坐标变换。下面是一个用C++编写的发布动态坐标变换的例子：

#include <ros/ros.h>
#include <tf2_ros/transform_broadcaster.h>
#include <geometry_msgs/TransformStamped.h>

int main(int argc, char** argv){
  ros::init(argc, argv, "tf2_broadcaster");
  ros::NodeHandle node;

  tf2_ros::TransformBroadcaster broadcaster;
  geometry_msgs::TransformStamped transformStamped;

  ros::Rate rate(10.0);
  while (node.ok()){
    transformStamped.header.stamp = ros::Time::now();
    transformStamped.header.frame_id = "base_link";
    transformStamped.child_frame_id = "camera_link";

    // 设置变换的位移和旋转
    transformStamped.transform.translation.x = 1.0;
    transformStamped.transform.translation.y = 0.0;
    transformStamped.transform.translation.z = 0.5;
    tf2::Quaternion q;
    q.setRPY(0, 0, 1.57);
    transformStamped.transform.rotation.x = q.x();
    transformStamped.transform.rotation.y = q.y();
    transformStamped.transform.rotation.z = q.z();
    transformStamped.transform.rotation.w = q.w();

    // 发布变换
    broadcaster.sendTransform(transformStamped);

    rate.sleep();
  }
  return 0;
}

在上面的例子中，我们使用`tf2_ros::TransformBroadcaster`类来创建一个变换广播器，并通过`broadcaster.sendTransform()`函数来发布变换。在循环中不断更新变换的时间戳和位移/旋转值即可实现动态变换。注意，`transformStamped.header.frame_id`表示父坐标系，`transformStamped.child_frame_id`表示子坐标系。在本例中，我们将发布一个相对于`base_link`坐标系的`camera_link`坐标系。