通过 tf_.transformPose获取tf坐标信息

主要函数

tf_.transformPose(frame1, ident, laser_pose);

frame1 为话题 frame_id， 如

std::string base_frame_;
std::string laser_frame_;
std::string map_frame_;
std::string odom_frame_;
//通过参数获取，获取不到直接默认值
  if(!private_nh_.getParam("base_frame", base_frame_))
    base_frame_ = "base_link";
  if(!private_nh_.getParam("map_frame", map_frame_))
    map_frame_ = "map";
  if(!private_nh_.getParam("odom_frame", odom_frame_))
    odom_frame_ = "odom";

其中 iden t为 tf::Stampedtf::Pose ，结构体如下

template //模版结构可以是tf::Pose tf:Point 这些基本的结构
class Stamped : public T{
     
public:
ros::Time stamp_; //记录时间
std::string frame_id_; //ID

Stamped() :frame_id_ (“NO_ID_STAMPED_DEFAULT_CONSTRUCTION”){
     }; //Default constructor used only for preallocation

Stamped(const T& input, const ros::Time& timestamp, const std::string & frame_id);

void setData(const T& input);
};
tf::StampedTransform

TF::stampedtransform是TF的一种特殊情况：它需要frame_id和stamp以及child_frame_id。

例子

laser_frame_ = scan.header.frame_id;
  // Get the laser's pose, relative to base.
  tf::Stamped<tf::Pose> ident;  //定义位姿
  tf::Stamped<tf::Transform> laser_pose; //定义激光雷达位姿信息
  ident.setIdentity();          //设为单位矩阵
  ident.frame_id_ = laser_frame_; //一般为laser_link
  ident.stamp_ = scan.header.stamp; //激光雷达时间戳
  try
  {
     
    tf_.transformPose(base_frame_, ident, laser_pose);
  }
  catch(tf::TransformException e)
  {
     
    ROS_WARN("Failed to compute laser pose, aborting initialization (%s)",
             e.what());
    return false;
  }