Simple RRTConnect planning fails

asked 2019-09-09 12:02:13 -0500

PatFGarrett gravatar image

updated 2019-09-09 12:05:40 -0500

Hello, I am trying to use the MoveIt package to generate the joint values for a pose/position target. Everyone time I try to plan a goal state the OMPL RRTConnect fails stating its unable to sample any valid states for the goal tree.

I know this is a common issue and the first question is always: " is the goal state truly reachable?" And I believe mine is.. the goal state I specify is only sliding forward with one joint. (Hopefully the code and picture will show this).

My process is in one terminal I run demo.launch (from a package I generated in setup_assistant) and in a second terminal I run my node.

Can anyone provide insight into what I may be doing wrong? Any advice would be greatly appreciated!!


#include <pluginlib/class_loader.h>
#include <ros/ros.h>

// MoveIt!
#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>

#include "std_msgs/Float32MultiArray.h"
#include "std_msgs/String.h"
ros::Publisher paramPub;
ros::Publisher display_publisher;
ros::Publisher marker_pub;

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

  static const std::string PLANNING_GROUP = "group1";
  moveit::planning_interface::MoveGroupInterface move_group(PLANNING_GROUP);
  moveit::planning_interface::PlanningSceneInterface planning_scene_interface;
  const robot_state::JointModelGroup* joint_model_group =

  // Visualization
  // ^^^^^^^^^^^^^
  // The package MoveItVisualTools provides many capabilties for visualizing objects, robots,
  // and trajectories in RViz as well as debugging tools such as step-by-step introspection of a script
  namespace rvt = rviz_visual_tools;
  moveit_visual_tools::MoveItVisualTools visual_tools("end");

  // Remote control is an introspection tool that allows users to step through a high level script
  // via buttons and keyboard shortcuts in RViz

  // RViz provides many types of markers, in this demo we will use text, cylinders, and spheres
  Eigen::Isometry3d text_pose = Eigen::Isometry3d::Identity();
  text_pose.translation().z() = 1.75;
  visual_tools.publishText(text_pose, "MoveGroupInterface Demo", rvt::WHITE, rvt::XLARGE);

  // Batch publishing is used to reduce the number of messages being sent to RViz for large visualizations

  // Getting Basic Information
  // ^^^^^^^^^^^^^^^^^^^^^^^^^
  ROS_INFO_NAMED("tutorial", "Planning frame: %s", move_group.getPlanningFrame().c_str());


  // We can also print the name of the end-effector link for this group.
  ROS_INFO_NAMED("tutorial", "End effector link: %s", move_group.getEndEffectorLink().c_str());

  // We can get a list of all the groups in the robot:
  ROS_INFO_NAMED("tutorial", "Available Planning Groups:");
  //std::copy(move_group.getJointModelGroupNames().begin(), move_group.getJointModelGroupNames().end(),
    //        std::ostream_iterator<std::string>(std::cout, ", "));

    std::cout << move_group.getEndEffectorLink() << std::endl;

  geometry_msgs::Pose target_pose1;
  target_pose1.orientation.w = 1.0;
  target_pose1.position.x = 0.35;
  target_pose1.position.y = 0.0;
  target_pose1.position.z = 0.0;
  move_group.setPoseTarget(target_pose1, "end");


  //move_group.setPositionTarget(0.3, 0.0, 0.0, "end");  

  // Now, we call the planner to compute the plan and visualize it.
  // Note that we are just planning, not asking move_group
  // to actually move the robot.
  //moveit::planning_interface::MoveGroupInterface::Plan my_plan;

  //bool success = (move_group.plan(my_plan) == moveit::planning_interface::MoveItErrorCode::SUCCESS);

  // Visualizing ...
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You might want to explicitly set the other quaternion values in target_pose1. You are only explicitly setting w, which means that the other x, y, z values might be default initialized to some garbge. A mucked-up rotation could easily cause the goal to out of reach for your robot.

BryceWilley gravatar image BryceWilley  ( 2019-09-11 09:50:06 -0500 )edit

@BryceWilley thank you for the response. I made the changes to ensure no random data is being set and still the same issue.

PatFGarrett gravatar image PatFGarrett  ( 2019-09-11 11:08:11 -0500 )edit

The only other missing piece here is what's in the robot's SRDF and in demo.launch. From the Could not identify parent group for end-effector 'end', it could be that your planning group is not set up correctly.

BryceWilley gravatar image BryceWilley  ( 2019-09-13 08:13:06 -0500 )edit