MoveIt! 学习笔记1- MoveGroup C++ Interface

此博文主要是用来记录ROS-Kinetic 中，用于机器人轨迹规划的MoveIt功能包的学习记录。 

英文原版教程见此链接：http://docs.ros.org/en/kinetic/api/moveit_tutorials/html/doc/move_group_interface/move_group_interface_tutorial.html

 引： MoveIt是基于MoveGroup这个类，MoveIt提供了一个相对简单的方式，令操作人员可以较为容易的操作机器人。 操作人员仅需发送各个关节的指定角度或者TCP的目标位置，即可控制机器人执行指令，移动到位。 MoveIt是通过ROS内部的Topic/Service和Action机制，向MoveGroup的节点发送指令。

主要内容：在上面的链接教程中，主要涉及到了C++的MoveIt！的接口。

                  以及如何创建规划组Move_Group，如何创建关节类型/目标点类型的轨迹，并使用Moveit自带规划器进行轨迹规划。 并且在RVIZ中显示出来规划完成的轨迹。

官方教程主要以代码实例为主，所以，在下边的代码中，主要通过注释的方式，解释代码含义，通过代码实例，学习MoveIt内部内容。

/*********************************************************************
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2013, SRI International
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of SRI International nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *********************************************************************/

/* Author: Sachin Chitta, Dave Coleman, Mike Lautman */

#include <moveit/move_group_interface/move_group_interface.h>
#include <moveit/planning_scene_interface/planning_scene_interface.h>

#include <moveit_msgs/DisplayRobotState.h>
#include <moveit_msgs/DisplayTrajectory.h>

#include <moveit_msgs/AttachedCollisionObject.h>
#include <moveit_msgs/CollisionObject.h>

#include <moveit_visual_tools/moveit_visual_tools.h>

int main(int argc, char** argv)
{
  ros::init(argc, argv, "move_group_interface_tutorial");
  ros::NodeHandle node_handle;
  ros::AsyncSpinner spinner(1);
  spinner.start();

  // BEGIN_TUTORIAL
  //
  // Setup
  // ^^^^^
  //
  // MoveIt! operates on sets of joints called "planning groups" and stores them in an object called
  // the `JointModelGroup`. Throughout MoveIt! the terms "planning group" and "joint model group"
  // are used interchangably.设定运动规划组名称
  static const std::string PLANNING_GROUP = "panda_arm";

  // The :move_group_interface:`MoveGroup` class can be easily
  // setup using just the name of the planning group you would like to control and plan for.
  //初始化运动规划组，并将前面设置的名称输入进来
  moveit::planning_interface::MoveGroupInterface move_group(PLANNING_GROUP);

  // We will use the :planning_scene_interface:`PlanningSceneInterface`
  // class to add and remove collision objects in our "virtual world" scene
  // 创建一个对象，用于添加和移除在仿真环境中的‘碰撞元件’（用来进行避障的轨迹仿真）
  moveit::planning_interface::PlanningSceneInterface planning_scene_interface;

  // Raw pointers are frequently used to refer to the planning group for improved performance.
  // 创建一个指针类型变量，用