# Vision-Based Hand Shadowing for Robotic Manipulation via Inverse Kinematics

arXiv: https://arxiv.org/abs/2603.11383 · HTML: https://mlsanity.com/paper/2603.11383/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 11 of its 23 references that are in the map.
- First posted on arXiv 11 Mar 2026.

## Builds on (most cited first, 11 of 11)

- [π0: A Vision-Language-Action Flow Model for General Robot Control](https://mlsanity.com/paper/2410.24164/) (2024)
- [Learning Fine-Grained Bimanual Manipulation with Low-Cost Hardware](https://mlsanity.com/paper/2304.13705/) (2023)
- [SmolVLA: A Vision-Language-Action Model for Affordable and Efficient Robotics](https://mlsanity.com/paper/2506.01844/) (2025)
- [MediaPipe Hands: On-device Real-time Hand Tracking](https://mlsanity.com/paper/2006.10214/) (2020)
- [DexCap: Scalable and Portable Mocap Data Collection System for Dexterous Manipulation](https://mlsanity.com/paper/2403.07788/) (2024)
- [AnyTeleop: A General Vision-Based Dexterous Robot Arm-Hand Teleoperation System](https://mlsanity.com/paper/2307.04577/) (2023)
- [Open-TeleVision: Teleoperation with Immersive Active Visual Feedback](https://mlsanity.com/paper/2407.01512/) (2024)
- [Learning Human-to-Humanoid Real-Time Whole-Body Teleoperation](https://mlsanity.com/paper/2403.04436/) (2024)
- [WiLoR: End-to-end 3D Hand Localization and Reconstruction in-the-wild](https://mlsanity.com/paper/2409.12259/) (2024)
- [Intel RealSense Stereoscopic Depth Cameras](https://mlsanity.com/paper/1705.05548/) (2017)
- [Bunny-VisionPro: Real-Time Bimanual Dexterous Teleoperation for Imitation Learning](https://mlsanity.com/paper/2407.03162/) (2024)

## Abstract (arXiv)

Teleoperation of low-cost robotic manipulators remains challenging due to the difficulty of retargeting human hand motion to robot joint commands. We present an offline hand-shadowing inverse-kinematics (IK) retargeting pipeline driven by a single egocentric RGB-D camera mounted on 3D-printed glasses. The pipeline detects 21 hand landmarks per hand using MediaPipe Hands, deprojects them into 3D via depth sensing, transforms them into the robot coordinate frame, and solves a damped-least-squares IK problem to produce joint commands for the SO-ARM101 robot (5 arm + 1 gripper joints). A gripper controller maps thumb-index finger geometry to grasp aperture with a multi-level fallback hierarchy. Actions are previewed in a physics simulation before replay on the physical robot. We evaluate the pipeline on a structured pick-and-place benchmark (5-tile grid, 10 grasps per tile, 3 independent runs) achieving an 86.7% +/- 4.2% success rate, and compare it against four vision-language-action (VLA) policies (ACT, SmolVLA, pi_0.5, GR00T N1.5) trained on leader-follower teleoperation data. We provide a quantitative error analysis of the pipeline, reporting a mean IK position error of 36.4 mm, trajectory smoothness metrics showing 57-68% jerk reduction from EMA smoothing, and an ablation study over the smoothing parameter. We also test the pipeline in unstructured real-world environments (grocery store, pharmacy) and find that success is reduced to 9.3% due to hand occlusion by surrounding objects. To mitigate this, we integrate WiLoR as an alternative hand detector, achieving an 8% improvement in hand detection rate over MediaPipe, highlighting both the promise and current limitations of marker-free analytical retargeting.