Papers
Topics
Authors
Recent
Search
2000 character limit reached

Immersive Human-in-the-Loop Control: Real-Time 3D Surface Meshing and Physics Simulation

Published 18 Dec 2024 in cs.RO | (2412.13752v1)

Abstract: This paper introduces the TactiMesh Teleoperator Interface (TTI), a novel predictive visual and haptic system designed explicitly for human-in-the-loop robot control using a head-mounted display (HMD). By employing simultaneous localization and mapping (SLAM)in tandem with a space carving method (CARV), TTI creates a real time 3D surface mesh of remote environments from an RGB camera mounted on a Barrett WAM arm. The generated mesh is integrated into a physics simulator, featuring a digital twin of the WAM robot arm to create a virtual environment. In this virtual environment, TTI provides haptic feedback directly in response to the operator's movements, eliminating the problem with delayed response from the haptic follower robot. Furthermore, texturing the 3D mesh with keyframes from SLAM allows the operator to control the viewpoint of their Head Mounted Display (HMD) independently of the arm-mounted robot camera, giving a better visual immersion and improving manipulation speed. Incorporating predictive visual and haptic feedback significantly improves teleoperation in applications such as search and rescue, inspection, and remote maintenance.

Summary

  • The paper demonstrates a novel TactiMesh system that integrates real-time semi-dense 3D meshing with immersive VR feedback and high-frequency haptic simulation.
  • It leverages a CARV-based SLAM pipeline and physics simulation to achieve 96.8% precision and 88.62% completeness while reducing resource usage.
  • The system effectively mitigates communication latency in teleoperation, enhancing situational awareness and robotic manipulation performance.

Immersive Human-in-the-Loop Control via Real-Time 3D Meshing and Physics Simulation

Introduction

This paper introduces the TactiMesh Teleoperator Interface (TTI), an integrated system for human-in-the-loop teleoperation leveraging predictive visual and haptic feedback, real-time 3D surface meshing, and immersive physics simulation. The proposed architecture significantly addresses the classical bottlenecks of remote robot teleoperation, including communication-induced haptic latency and spatial awareness challenges. The intersection of real-time semi-dense monocular surface reconstruction, predictive VR-mediated interfaces, and tight feedback integration through a physics simulator represents a distinctive contribution in haptic-enabled immersive teleoperation.

Architecture and Methodology

The TTI system consists of three core components: incremental surface mesh generation using a CARV-based SLAM pipeline, immersive visualization with predictive display features employing a head-mounted display (HMD), and real-time physics simulation in Gazebo incorporating a digital twin of the Barrett WAM manipulator.

Real-Time Semi-Dense Surface Mesh Reconstruction

TTI utilizes a monocular RGB stream, with SLAM for pose estimation (ORB-SLAM2) and a semi-dense CARV variant for depth estimation and surface meshing. Unlike dense point cloud approaches, which are both bandwidth- and memory-intensive, the semi-dense representation preserves critical geometric structures while optimizing for real-time operation and computational/resource efficiency. Updates to the mesh are triggered with each incoming SLAM keyframe, with efficient management of texture updates for each mesh vertex, supporting view-dependent predictive texturing.

Immersive Predictive Display and Visual Feedback

Unlike traditional 2D teleoperation displays, the immersive display supports independent viewpoint control through a VR interface leveraging the operator’s head pose. The virtual camera within Gazebo provides stereoscopic, predictive visual feedback at high framerates and low latency via asynchronous ROS2-based streaming and efficient web visualization. Key to this module is the decoupling of HMD viewpoint from the physical robot camera, substantially enhancing situational awareness and manipulation performance while minimizing cognitive load.

Physics Simulation and Haptic Feedback

The physics simulation component (Gazebo) integrates the digital twin of the WAM manipulator and the live-updating surface mesh. Predictive haptic feedback is computed via collision/contact events between the mesh and manipulator in the simulator. The system bypasses conventional limitations with delayed haptic feedback—feedback is generated directly from the physical simulation, matched to operator intent, and delivered with high-frequency updates (250 Hz). This design effectively mitigates the effects of communication lag inherent in remote force feedback.

Experimental Results

Surface Mesh Quality and Resource Efficiency

Experiments on the EuRoC MAV Room 101 dataset show TTI’s method achieves a 96.8% precision and 88.62% completeness in the reconstructed surface mesh—outperforming prior monocular CARV-based baselines by clear margins while using fewer mesh vertices and faces. The compactness of the surface mesh (1.4 MB for room-scale OBJ; 900 KB at tabletop scale) supports real-time updates with limited bandwidth and resource usage.

Visual and Haptic Latency

The immersive display achieves video streaming at 1696x1600 resolution, 30 FPS, and approximately 10ms end-to-end latency. For haptic feedback, the custom Gazebo plugin enables high update frequency and pre-contact detection (20 mm early via min depth parameter), eliminating oscillatory effects associated with lower feedback rates. When deploying optimized Gazebo configurations, the real-time performance factor (RTF) for TTI's mesh reached 0.52 on the VR101 benchmark, the highest among tested methods.

Practical System Observations

Integration with an Oculus Quest-2 HMD and hand controllers demonstrated the system’s compatibility with current commercial VR hardware. Modifications to Gazebo’s camera and rendering pipeline facilitated full-scene visualization, including visualization of physical interactions and robotic effort dynamics.

Theoretical and Practical Implications

This research directly addresses the critical trade-off between mesh detail and resource constraints in teleoperation environments, establishing a paradigm where geometric fidelity, immersive feedback, and low-latency control are simultaneously achievable. The predictive decoupling of visual and haptic feedback from raw sensor data, mediated by physical simulation and efficient 3D representations, enables robust teleoperation in scenarios that are susceptible to network delays and operator overload.

For practical deployments, this architecture greatly facilitates robotic manipulation in high-risk or constrained environments (e.g., search and rescue, remote inspection, and medical telerobotics), where model fidelity and fast, reliable feedback are mission-critical. The system’s modularity—specifically, the reliance on open standards (Gazebo, ROS1/2, WebRTC)—also positions it for integration with a range of robotic platforms.

Future Directions

Potential future work includes integration of learning-based surface completion to further improve mesh completeness from sparse observations, dynamic fusion with prior maps or semantic labels, and automatic adaptation of mesh resolution and streaming rates based on environmental complexity and available bandwidth. Real-world testing in highly unstructured and dynamic task domains (e.g., disaster response with multiple operators and mobile manipulators) will further stress-test and validate the system’s robustness. Moreover, interface improvements to minimize VR-induced discomfort while maintaining high immersion remain an open area, especially as haptic and kinesthetic interfaces grow in sophistication.

Conclusion

The TactiMesh Teleoperator Interface sets a new technical standard for immersive, low-latency, human-in-the-loop robot teleoperation. Through a synergistic combination of incremental 3D surface meshing, immersive predictive VR displays, and real-time haptic feedback enabled by a physics-based digital twin, TTI achieves marked improvements in both precision and operational efficacy over existing approaches. This work demonstrates the critical importance of real-time, mesh-centric environment models with tightly integrated simulation and feedback in advancing the capabilities of remote teleoperation across demanding application domains.

Paper to Video (Beta)

Whiteboard

No one has generated a whiteboard explanation for this paper yet.

Open Problems

We haven't generated a list of open problems mentioned in this paper yet.

Collections

Sign up for free to add this paper to one or more collections.