Hamlyn-dVRK: Table-Top Peg Transfer - README
At a Glance
High-fidelity teleoperated demonstrations of a bimanual da Vinci Research Kit (dVRK) robot performing peg transfer on a table-top training rig. The robot uses DeBakey forceps (left) and a needle driver (right) to pick up pegs, perform a handover between tools, and place pegs onto specified posts.
Dataset Overview
This dataset contains teleoperated trajectories of trained operators using the dVRK to perform peg transfer on a table-top training apparatus. The goal is to pick up a peg with the left hand, transfer it to the right hand, and place it accurately onto a target post according to a given instruction.
Task Logic & Execution: The operator utilises the Patient Side Manipulators (PSMs) equipped with DeBakey forceps (left) and a needle driver (right).
- Pick (Left Hand): The left hand grasps the instructed peg.
- Handover + Place (Right Hand): The peg is transferred to the right hand and placed onto a target post on the board.
Key Features:
- Table-Top Dexterity Primitive: Clean visual scene with rigid objects, supporting accurate benchmarking of bimanual handovers and placement.
- Instruction-Conditioned Placement: Demonstrations follow a given instruction specifying which peg to move and where to place it.
| Total Trajectories | 317 |
| Total Hours | 0.545 |
| Data Type | [ ] Clinical [ ] Ex-Vivo [x] Table-Top Phantom [ ] Digital Simulation [ ] Physical Simulation [ ] Other |
| License | CC BY 4.0 |
| Version | 1.0 |
Hamlyn dVRK Dataset Overview
This is part of the Hamlyn dVRK Dataset, which encompasses six distinct surgical tasks. All data were collected through teleoperation on bimanual tasks performed on ex-vivo animal samples and phantoms.
Task Conditioning
The tasks are categorized into two types:
- Non-conditioned: Single sentence task descriptions
- Language-conditioned: Multiple variants of task descriptions across episodes
Dataset Statistics
- Total Episodes: 972
- Total Frames: 545k @ 30Hz
- Dataset Duration: 5.04 hours
Episode Outcomes
| Outcome Category | Episodes | Description |
|---|---|---|
| Success | 780 | Task completed successfully with specified conditions |
| Recovery | 110 | Task finished with recovery behavior |
| Failed | 82 | Task failed to complete |
*Success rates vary across tasks due to varying difficulty levels for operators during teleoperation.
Tasks & Domain
Domain
Select the primary domain for this dataset.
- Surgical Robotics
- Ultrasound Robotics
- Other Healthcare Robotics
Demonstrated Skills
This specific dataset subset focuses on Peg Transfer.
Note: This is part of the Hamlyn dVRK Data Collection which also includes:
- Tissue Retraction / Exposure
- Knot Tying
- Suturing (Single Loop)
- Suturing (Dual Loop)
- Peg Transfer
- Needle Grasp and Handover
Data Collection Details
Collection Method
How was the data collected?
- Human Teleoperation
- Programmatic/State-Machine
- AI Policy / Autonomous
- Other
Operator Details
| Description | |
|---|---|
| Operator Count | 2 |
| Operator Skill Level | [ ] Expert (e.g., Surgeon, Sonographer) [x] Intermediate (e.g., Trained Researcher) [x] Novice (e.g., ML Researcher with minimal experience) [ ] N/A |
| Collection Period | From 2025-12-01 to 2026-01-15 |
| Input Interface | Teleoperation interface with bimanual Force Dimension Sigma 7 haptic device |
Recovery Demonstrations
Does this dataset include examples of recovering from failure?
- Yes
- No
If yes, please briefly describe the recovery process:
In the peg transfer task, failure modes typically involve dropping the peg during transport, an unstable handover, or misplacement onto the post. In these instances, the operator does not abort the episode but performs a recovery manoeuvre: re-grasping the peg, re-aligning the approach, and repeating the handover and placement steps.
Diversity Dimensions
Check all dimensions that were intentionally varied during data collection.
- Camera Position / Angle
- Lighting Conditions
- Target Object (Varied peg and target post)
- Spatial Layout (Varied board pose / peg arrangement)
- Robot Embodiment
- Task Execution (Left vs. Right hand dominance / Approach angle)
- Background / Scene
- Initial Robot Configuration (Table-top domain randomisation)
Elaboration on Diversity:
- Target Object: A table-top peg board was used. Diversity is achieved through varying which peg is selected and which post is the placement target.
- Spatial Layout: The board pose and/or peg arrangement are varied between sets to reduce overfitting to absolute coordinates.
- Task Execution: Operators vary approach angle, grasp point, and handover strategy to maintain stable transport and accurate placement.
- Initial Robot Configuration: End-effectors were reset to a randomised "home" position above the workspace before each trajectory.
🛠️ Equipment & Setup
Robotic Platform(s)
List the primary robot(s) used.
- Robot 1:
dVRK (da Vinci Research Kit) - Patient Side Manipulators (PSM1, PSM2)
Sensors & Cameras
List the sensors and cameras used. Specify model names where possible.
| Type | Model/Details |
|---|---|
| Primary Camera | Intel RealSense D405 (RGB + Depth), 848x480 @ 30fps |
| Wrist Camera | INSKAM 5.5mm USB Endo-Cam (Right/Left Arm) with custom built mount, view angle 66 degree, focal length 4-10cm, 640x480 @ 24fps |
| Kinematics | dVRK High-Frequency Joint Encoders (100Hz) |
🎯 Action & State Space Representation
The dataset follows the standard LeRobot format for bimanual manipulation.
Action Space Representation
Primary Action Representation:
- Absolute Cartesian (position/orientation relative to robot base)
- Relative Cartesian
- Joint Space
Orientation Representation:
- Quaternions (x, y, z, w)
- Euler Angles
- Rotation Matrix
Reference Frame:
- Robot Base Frame (Base of each PSM arm)
- Camera Frame
Action Dimensions:
action: [x, y, z, qx, qy, qz, qw, gripper_angle, x, y, z, qx, qy, qz, qw, gripper_angle]
- The first 8 dimensions are for the left arm and last 8 dimensions are for the right arm
- x, y, z: Absolute position in PSM base frame (meters)
- qx, qy, qz, qw: Absolute orientation as quaternion
- gripper_angle: Normalized jaw opening angle (1 = opened, 0 = closed)
State Space Representation
State Information Included:
- Joint Positions
- Joint Velocities
- End-Effector Pose (No extra end-effector used with dVRK)
- Gripper State
Primary State:
observation.state: [x, y, z, qx, qy, qz, qw, gripper_angle, x, y, z, qx, qy, qz, qw, gripper_angle]
- The first 8 dimensions are for the left arm and last 8 dimensions are for the right arm
- x, y, z: Absolute position in PSM base frame (meters)
- qx, qy, qz, qw: Absolute orientation as quaternion
- gripper_angle: Normalized jaw opening angle (1 = opened, 0 = closed)
State Dimensions:
observation.state.left_arm_cartesian: [x, y, z, qx, qy, qz, qw, gripper_angle]
observation.state.right_arm_cartesian: [x, y, z, qx, qy, qz, qw, gripper_angle]
observation.state.left_arm_joint: [j1, j2, j3, j4, j5, j6, gripper_angle]
observation.state.right_arm_joint: [j1, j2, j3, j4, j5, j6, gripper_angle]
- j1-j6: Joint positions for 6-DOF PSM arm (radians)
- gripper_angle: Normalized jaw opening angle (1 = opened, 0 = closed)
⏱️ Data Synchronization Approach
Describe how you achieved proper data synchronization.
Distributed Synchronization Architecture: The data collection setup involves a distributed system with a robot control machine that teleop the dVRK and a sensor recording machine that stream kinematics, and videos from camers.
- Clock Sync: We utilize Chrony (NTP) to enforce strict time alignment between the two workstations, minimizing clock skew to < 3.3 ms.
- Timestamping: All data streams (camera RGB and depth images, wrist camer images, robot kinematics) are timestamped with ROS wall-time headers at the exact moment of capture.
- Delay Compensattion and Trimming: The different cameras can introduce small relative delays. These delays are first estimated and compensated by applying a common temporal offset to each stream. Subsequently, all streams are temporally trimmed to their common interval, bounded by the latest start time and the earliest end time across all modalities.
- Alignment: During the LeRobot conversion process, frames from all data streams are aligned to a reference timeline at 30 Hz30 Hz. This is achieved via nearest-neighbor temporal interpolation based on the synchronized ROS timestamps.
Attribution & Contact
Please provide attribution for the dataset creators and a point of contact.
| Dataset Lead | Jianhao Su, Kaizhong Deng, Zhaoyang Jacopo Hu |
| Institution | The Hamlyn Centre for Robotic Surgery, Imperial College London |
| Contact Email | k.deng21@imperial.ac.uk (for technical issues), stamatia.giannarou@imperial.ac.uk (for correspondence) |
| Citation (BibTeX) | |