PR2 gripper with GripperCommand or FollowJointTrajectory

[harsh deshpande]

I'm trying to use Pr2 gripper with UR5. I want to use action interface for the gripper. For this I have tried with both - 

(Have kept details only related to the gripper)

1. GripperCommand: 

controllers.yaml

controller_list:

  - name: r_gripper_controller

    action_ns: gripper_cmd

    default: true

    type: GripperCommand

    joints: [r_gripper_l_finger_joint]

control_grip.yaml

r_gripper_controller:

  type: effort_controllers/GripperActionController

  joint: r_gripper_l_finger_joint

  gains:

     r_gripper_l_finger_joint: {p: 100.0, i: 0.01, d: 10.0}

    msg = GripperCommandGoal()

    msg.command.position = 0.2

    msg.command.max_effort = 10.0

    client_grip.send_goal(msg)

    client_grip.wait_for_result()

    if client_grip.get_state() == GoalStatus.SUCCEEDED:

    rospy.loginfo("opened!")

    rospy.loginfo("gripper state: %i", client_grip.get_state())

But here the goal remains ACTIVE infinitely. Same is the case for closing as well.

2. FollowJointTrajectory

controllers.yaml

controller_list:

  - name: r_gripper_controller

    action_ns: follow_joint_trajectory

    default: true

    type: FollowJointTrajectory

    joints: [r_gripper_l_finger_joint]

control_grip.yaml

r_gripper_controller:

  type: effort_controllers/JointTrajectoryController

  joint: r_gripper_l_finger_joint

  gains:

     r_gripper_l_finger_joint: {p: 100.0, i: 0.01, d: 10.0}

msg = FollowJointTrajectoryGoal()

msg.trajectory.header.stamp = rospy.Time.now() + rospy.Duration(0.4) 

msg.trajectory.joint_names = ['r_gripper_l_finger_joint']

msg.trajectory.points.append(JointTrajectoryPoint(positions=[0.2], time_from_start = rospy.Duration(2)))

"Sometimes" the open works (position = 0.2), but in case of close (position = 0.0), the goal is either ABORTED (4) or REJECTED (5)

What am I doing wrong?

[harsh deshpande]

OK I'm seeing a strange behavior now. I removed the code pertaining to the UR5 and used GripperCommand for PR2 gripper and it works perfectly fine. 

It opens and closes and returns the SUCCEEDED code.

But when I send a trajectory goal for the arm (which returns an ABORTED code after completing the trajectory), the GripperCommand goal waits infinitely.

What has the response of the trajectory goal got to do anything with the gripper goal?