260820_eef

learner1119/260820 unchanged, plus end-effector (task space) columns for both arms and a GR00T meta/modality.json. ROBOTIS FFW-SH5 in MuJoCo, single task "pick and place" (saggar onto a plate), 100 episodes, 44,136 frames, 20 fps, LeRobot v2.1.

Features

key	shape	content
observation.state	16	original, unchanged: arm_l_joint1..7, gripper_l_joint1, arm_r_joint1..7, gripper_r_joint1
action	16	original, unchanged: commanded joint targets, same names
observation.eef	18	added: lpalm pose (9) + rpalm pose (9), each xyz (m) + rot6d, in the arm_base_link frame; FK of observation.state
action.eef	18	added: same layout; FK of action (commanded pose, not the next measured state)
observation.images.agentview, initial.obj_pos, index columns		original, unchanged

• rot6d = first two rows of the rotation matrix, flattened (GR00T ActionFormat.XYZ_ROT6D).
• arm_base_link carries the lift joint and has the same axes as world (x front, y left, z up), so the pose does not depend on torso height (lift and head joints were not recorded).
• Grippers are not converted; use the gripper slices of observation.state / action.

GR00T meta/modality.json

group	state source	action source
left_arm / left_gripper / right_arm / right_gripper	observation.state [0:7] / [7:8] / [8:15] / [15:16]	action, same slices
left_eef_9d / right_eef_9d	observation.eef [0:9] / [9:18]	action.eef, same slices

Video cam_head = observation.images.agentview; annotation human.task_description = task_index. A GR00T modality config picks joint groups (joint space) or EEF groups (task space) from the same dataset. Checked with gr00t/data/stats.py and a relative EEF (XYZ_ROT6D, horizon 50) config on left_eef_9d + left_gripper.

How it was made

FK in the lab's ri_motion_v5 style (merge_mjcfs → MuJoCoParser → env.forward(q, joint_names) → env.get_T("lpalm"/"rpalm","site"), expressed in env.get_T("arm_base_link","body") with view_in_local), on the robot MJCF asset/robotis_ffw/ffw_sh5_site_added_fixed.xml of the POSCO MuJoCo benchmark repo (notebook tools/joint_to_eef_dataset.ipynb). env.forward clips joints to their limits; this touches only joint2 near its 0° lower limit (left: 622 state / 171 action frames, ≤ 0.06°; right: 299 state frames, ≤ 0.001°). The original columns were checked to be identical to the source parquet files.