The meaning of error msgs in arm_navigation and how to debug

edit

I followed this tutorial

http://www.ros.org/wiki/move_arm/Tutorials/MoveArmPoseGoal

and modified it slightly to make it move to four different positions.

Sometime errors happened such as:

Action failed: ACTIVE
Timed out achieving goal A
Action failed: PENDING

When error occurred, sometimes it still took the end-effector to the right place, while sometimes the arm wouldn't move. This is my code, it's almost the same as the one in the tutorial.

#include <ros/ros.h>
#include <actionlib/client/simple_action_client.h>

#include <arm_navigation_msgs/MoveArmAction.h>
#include <arm_navigation_msgs/utils.h>

int main(int argc, char **argv){
  if(argc!=4)
  {
      ROS_INFO("Wrong Argument : rosrun package binary_file x y z");
      return -1;
  }

  ros::init (argc, argv, "move_arm_pose_goal_test");
  ros::NodeHandle nh;
  actionlib::SimpleActionClient<arm_navigation_msgs::MoveArmAction>     move_arm("move_right_arm",true);
  move_arm.waitForServer();
  ROS_INFO("Connected to server");
  arm_navigation_msgs::MoveArmGoal goalA;

  goalA.motion_plan_request.group_name = "right_arm";
  goalA.motion_plan_request.num_planning_attempts = 1;
  goalA.motion_plan_request.planner_id = std::string("");
  goalA.planner_service_name =     std::string("ompl_planning/plan_kinematic_path");
  goalA.motion_plan_request.allowed_planning_time = ros::Duration(5.0);

  arm_navigation_msgs::SimplePoseConstraint desired_pose;
  desired_pose.header.frame_id = "torso_lift_link";
  desired_pose.link_name = "r_wrist_roll_link";
  desired_pose.pose.position.x = atof(argv[1]);
  desired_pose.pose.position.y = atof(argv[2]);
  desired_pose.pose.position.z = atof(argv[3]);

  desired_pose.pose.orientation.x = 0.0;
  desired_pose.pose.orientation.y = 0.0;
  desired_pose.pose.orientation.z = 0.0;
  desired_pose.pose.orientation.w = 1.0;

  desired_pose.absolute_position_tolerance.x = 0.02;
  desired_pose.absolute_position_tolerance.y = 0.02;
  desired_pose.absolute_position_tolerance.z = 0.02;

  desired_pose.absolute_roll_tolerance = 0.04;
  desired_pose.absolute_pitch_tolerance = 0.04;
  desired_pose.absolute_yaw_tolerance = 0.04;

      arm_navigation_msgs::addGoalConstraintToMoveArmGoal(desired_pose,goalA);

  if (nh.ok())
  {
    move_arm.sendGoal(goalA);
    if(move_arm.waitForResult(ros::Duration(200.0)))
    {
      move_arm.cancelGoal();
      ROS_INFO("Timed out achieving goal A");
    }
    else
    {
      actionlib::SimpleClientGoalState state = move_arm.getState();
      bool success = (state == actionlib::SimpleClientGoalState::SUCCEEDED);
      if(success)
        ROS_INFO("Action finished: %s",state.toString().c_str());
      else
        ROS_INFO("Action failed: %s",state.toString().c_str());
    }
  }
  ros::shutdown();
}

I would like to know what's the meaning of the errors :

PENDING
ACTIVE
RECALLED
REJECTED
PREEMPTED
ABORTED
SUCCEEDED
LOST

And how to debug using these error msgs.( the timeout msg as well)

Besides, why is that sometimes the arm can still move when the error occurred.

Thanks for any advise~

.----------------------------------------.

The four positions I've test :

./ik_arm_traj 0.5 0.0 -0.2

./ik_arm_traj 0.5 -0.4 -0.2

./ik_arm_traj 0.5 -0.4 0.2

./ik_arm_traj 0.5 0.0 0.2

---modified---

I've follow dornhege's advise and try to print out the result defined by MoveArm.action in arm_navigation_msgs.

ROS_INFO("Action result:%d", move_arm.getResult()->error_code.val)

However, the error code always be 0, no matter whether the arm can move or not. So I still can't know what makes the move_arm action fail.

Besides, I would like to ask that since the move_arm is built on actionlib, how can the arm sometimes still moves while the status of the action server reported failed?