Cannot found index_tip_link IK solution.

[taichiH]

I'd like to solve IK but always IK failed, when I set aero::eef::index argument to setFromIK. Is this failure only this version or we couldn't solve index_tip_link IK from before?

I show the log below.

[ INFO] [1527849936.125180840] [/ik_sample_node:ros.aero_std]: start loading joint model groups
[ INFO] [1527849936.125280067] [/ik_sample_node:ros.aero_std]: ----------------------------------------
[ INFO] [1527849936.125304573] [/ik_sample_node:ros.aero_std]:   AERO MOVEIT INTERFACE is initialized
[ INFO] [1527849936.125327918] [/ik_sample_node:ros.aero_std]: ----------------------------------------
[ WARN] [1527849936.125573513] [/ik_sample_node:ros.rosconsole_bridge.class_loader.ClassLoader]: SEVERE WARNING!!! Attempting to unload library while objects created by this loader exist in the heap! You should delete your objects before attempting to unload the library or destroying the ClassLoader. The library will NOT be unloaded.
[ INFO] [1527849936.125637550] [/ik_sample_node:ros.aero_sandbox]: reseting robot pose
[ INFO] [1527849939.126965550] [/ik_sample_node:ros.aero_sandbox]: r_trans: 0.326068, -0.251570, 1.473584
[ERROR] [1527849939.127726926] [/ik_sample_node:ros.rosconsole_bridge.console_bridge]: Cannot compute IK for query 0 pose reference frame 'r_index_tip_link'
[ERROR] [1527849939.127794940] [/ik_sample_node:ros.rosconsole_bridge.console_bridge]: Available tip frames: [r_hand_link, ]
[ WARN] [1527849939.127855703] [/ik_sample_node:ros.aero_sandbox]: ik failed
[ INFO] [1527849939.127917342] [/ik_sample_node:ros.aero_sandbox]: r_trans after ik: 0.326068, -0.251570, 1.473584
[ INFO] [1527849939.127962025] [/ik_sample_node:ros.aero_sandbox]: demo node finished

[sasabot]

can you elaborate more on how you tested this? are you sure you're a applying a valid I.K. position? For example, you can set a random pose and get the index pose from

auto p = robot->getEEFPosition(aero::rarm, aero::eef::index);
auto q = robot->getEEFOrientation(aero::rarm, aero::eef::index);
auto goal = aero::Translation(p) * q;

Does applying this sort of goal work? Note, that just changing the argument in the sample code has no guarantee that there is a solution for the index finger. Those values are only checked with aero::eef::grasp.

[taichiH]

First, I send reset_manip pose and check r_index_tip_link pose using tf_echo.

rosrun tf tf_echo /base_link /r_index_tip_link

Second, set pose and orientation got from tf_echo to aero::eef::index IK goal. This mean I set pose same as reset-manip pose. so this inverse-kinematics should solved but not found solution.

I tried way you explained above but result is also not good. Simple code shown below.

@YoheiKakiuchi said this problem may be occurred because index joint is not fix-joint.

#include <aero_std/AeroMoveitInterface.hh>

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

  aero::interface::AeroMoveitInterface::Ptr robot(new aero::interface::AeroMove\
  itInterface(nh));
  ROS_INFO("reseting robot pose");
  robot->setPoseVariables(aero::pose::reset_manip);
  robot->sendModelAngles(3000);
  sleep(3);

  auto p = robot->getEEFPosition(aero::arm::rarm, aero::eef::index);
  auto q = robot->getEEFOrientation(aero::arm::rarm, aero::eef::index);
  auto goal = aero::Translation(p) * q;
  bool r_ik_result = robot->setFromIK(aero::arm::rarm, aero::ikrange::wholebody, goal, aero::eef::index);

  if (r_ik_result) {
    ROS_INFO("ik success !");
    robot->sendModelAngles(3000);
    sleep(3);
  } else {
    ROS_WARN("ik failed");
  }

  ROS_INFO("demo node finished");
  ros::shutdown();
  return 0;
  }    

[sasabot]

OK, I think this is a valid problem.

In the meantime, I think the only way to get along with this, is to convert index poses to grasp/hand poses and solve ik with eef::grasp or eef::hand. As I see maintenance problems with aero::eef not being stable for some functions (e.g. #337 where planning with grasp_link does not work with indigo), I would recommend the api to remove eef options and solve everything with eef::hand only; and instead have a conversion function between eefs as in #333)

[YoheiKakiuchi]

@sasabot aero::eef::index existed at v1.0.0, Did anyone use it ? Did it not work well at that time?

[sasabot]

checked some of my old codes but none of them were using aero::eef::index.

it seems that I always solved with aero::eef::grasp. every time I wanted to solve for aero::eef::index, I first solved the IK, then called getEEFPosition(aero::eef::index), and used the lifter to adjust the finger tip position.