update readme

README.md

@@ -2,7 +2,7 @@
 license: cc-by-nc-4.0
 pretty_name: "RoboCAS: A Benchmark for Robotic Manipulation in Complex Object Arrangement Scenarios"
 task_categories:
-  - "RobotManipulation"
+  - robotics
 ---
 
 # RoboCAS: A Benchmark for Robotic Manipulation in Complex Object Arrangement Scenarios
@@ -12,6 +12,60 @@ task_categories:
 This repo contains several demonstration trajectories generated by [RoboCAS-v0](https://github.com/notFoundThisPerson/RoboCAS-v0).
 Details can be found on GitHub.
 
+## Dataset Structure
+
+Trajectories are contained in the zip files,each contains the following tasks:
+```
+scattered.zip: Picking task in the scattered scene.
+orderly.zip: Selecting task in the orderly scene.
+stacked.zip: Searching task in the stacked scene.
+```
+Details can be found in the paper.
+Each trajectory is arranged as the following structure:
+```
+.
+|-- data_info.json                          # Overview of the dataset information, in dictionary format.
+|-- episode_0000000                         # Trajectory 0.
+|   |-- episode_info.npz                    # Actions and robot states in the trajectory.
+|   |-- gripper_camera                      # Data of the camera mounted on the gripper.
+|   |   |-- cam_pos_wrt_${parent}.npy       # Camera pose w.r.t. its parent link.
+|   |   |-- intrinsic.npy                   # Intrinsic of this camera.
+|   |   |-- rgb                             # RGB images in this trajectory.
+|   |   |   |-- 0000.png                    # Image at step 0.
+|   |   |   |-- ...
+|   |   |-- depth                           # Depth images in this trajectory. Same structure as "rgb".
+|   |       |-- ...
+|   |-- base_camera                         # Data of the camera mounted on the robot base. Same structure as "gripper_camera".
+|   |   |-- ...
+|   |-- static_camera                       # Data of the camera mounted on the ground. Same structure as "gripper_camera".
+|   |   |-- ...
+|-- episode_0000001                         # Same structure as "episode_0000000".
+|-- ...
+```
+In each trajectory folder, the *episode_info.npz* file contains the trajectory of the agent, the structure and the explanations of each item is as follows. 
+All of the Quaternion in our dataset are stored in "xyzw" order.
+All relative transforms are calculated under the frame of the last time step, i.e. $\Delta T_{t} = T_{t-1}^{-1} T_{t}$, where $\Delta T_{t}, T_{t} \in SE(3)$ are the relative action and the pose at time step $t$.
+```
+rel_pos             # Relative position shift of the EEF w.r.t. the last EEF pose in Cartesian coordinate.
+rel_orn             # Relative orientation shift of the EEF w.r.t. the last EEF pose in Quaternion.
+ee_pos              # Absolute position of the EEF w.r.t. the arm base in Cartesian coordinate.
+ee_orn              # Absolute orientation of the EEF w.r.t. the arm base in Quaternion.
+robot_joints        # Joint angles of the arm.
+arm_joint_vel       # Velocities of the arm joints.
+base_pos            # Position of the arm base w.r.t. the world in Cartesian coordinate.
+base_orn            # Orientation of the arm base w.r.t. the world in Quaternion.
+base_rel_pos        # Relative position shift of the arm base w.r.t. the the pose in last step in Cartesian coordinate.
+base_rel_orn        # Relative orientation shift of the arm base w.r.t. the the pose in last step in Quaternion.
+gripper_width       # Open width of the gripper fingers.
+gripper_status      # Open/close command of the gripper.
+episode_length      # Length of the trajectory.
+language_goal       # Global goal instruction of this trajectory.
+language_embedding  # Embedding of the goal instruction generated by \href{https://huggingface.co/sentence-transformers/all-MiniLM-L6-v2}{Mini LAMMA}.
+step_lang_goals     # Goal annotation of the sub-task for each step of action in this trajectory.
+step_goal_embs      # Embedding of step goals generated by \href{https://huggingface.co/sentence-transformers/all-MiniLM-L6-v2}{Mini LAMMA}.
+step_goal_type      # Type of the sub-task goals in each step.
+```
+
 ## Cite
 ```
 @inproceedings{zheng2024robocas