Unexpected end effector frame from generated IKFast solver

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Unexpected end effector frame from generated IKFast solver

vchwang
I generated a solver using the following line:

openrave.py --database inversekinematics --robot=robots/pr2-beta-static.zae
--manipname=rightarm  --freejoint=r_upper_arm_roll_joint --freeinc=0.01

Looking at the manipulators list, I see

name            base            end                         arm-dof gripper-dof arm                     gripper
---------------------------------------------------------------------------------------------------------------
leftarm_camera  torso_lift_link l_forearm_cam_optical_frame 5       0           15,16,17,18,19
rightarm_camera torso_lift_link r_forearm_cam_optical_frame 5       0           27,28,29,30,31
head_torso      base_link       wide_stereo_optical_frame   3       0           12,13,14
head            torso_lift_link wide_stereo_optical_frame   2       0           13,14
rightarm_torso  base_link       r_gripper_palm_link         8       1           12,27,28,29,30,31,32,33 34
rightarm        torso_lift_link r_gripper_palm_link         7       1           27,28,29,30,31,32,33    34
leftarm_torso   base_link       l_gripper_palm_link         8       1           12,15,16,17,18,19,20,21 22
leftarm         torso_lift_link l_gripper_palm_link         7       1           15,16,17,18,19,20,21    22
---------------------------------------------------------------------------------------------------------------
name            base            end                         arm-dof gripper-dof arm                     gripper


which I assume means the solver will return forward kinematic solutions for the r_gripper_palm_link frame relative to torso_lift_link. However, when I visualize the solution on the PR2 through ROS TF and move the arm around, the actual XYZ position of the solution frame seem to track the XYZ of r_gripper_tool_frame. The orientation doesn't match either the r_gripper_palm_link or r_gripper_tool_frame. Does Openrave have different frames or did I make a mistake elsewhere?

Thanks,
Victor
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Re: Unexpected end effector frame from generated IKFast solver

Rosen Diankov
Administrator
in openrave, a manipulator can have an offset from the link it is attached to. perhaps your the rightarm manipulator has this local offset?
if you open in python, you can see the offset with:

robot.GetManipulator('rightarm').GetLocalToolTransform()

best,



2013/11/20 vchwang <[hidden email]>
I generated a solver using the following line:

openrave.py --database inversekinematics --robot=robots/pr2-beta-static.zae
--manipname=rightarm  --freejoint=r_upper_arm_roll_joint --freeinc=0.01

Looking at the manipulators list, I see

name            base            end                         arm-dof
gripper-dof arm                     gripper
---------------------------------------------------------------------------------------------------------------
leftarm_camera  torso_lift_link l_forearm_cam_optical_frame 5       0
15,16,17,18,19
rightarm_camera torso_lift_link r_forearm_cam_optical_frame 5       0
27,28,29,30,31
head_torso      base_link       wide_stereo_optical_frame   3       0
12,13,14
head            torso_lift_link wide_stereo_optical_frame   2       0
13,14
rightarm_torso  base_link       r_gripper_palm_link         8       1
12,27,28,29,30,31,32,33 34
rightarm        torso_lift_link r_gripper_palm_link         7       1
27,28,29,30,31,32,33    34
leftarm_torso   base_link       l_gripper_palm_link         8       1
12,15,16,17,18,19,20,21 22
leftarm         torso_lift_link l_gripper_palm_link         7       1
15,16,17,18,19,20,21    22
---------------------------------------------------------------------------------------------------------------
name            base            end                         arm-dof
gripper-dof arm                     gripper


which I assume means the solver will return forward kinematic solutions for
the r_gripper_palm_link frame relative to torso_lift_link. However, when I
visualize the solution on the PR2 through ROS TF and move the arm around,
the actual XYZ position of the solution frame seem to track the XYZ of
r_gripper_tool_frame. The orientation doesn't match either the
r_gripper_palm_link or r_gripper_tool_frame. Does Openrave have different
frames or did I make a mistake elsewhere?

Thanks,
Victor



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