Multi-Fingered Dynamic Grasping of Unknown Objects in Real-Time

Concepts de base

A practical framework for real-time multi-fingered grasping of unknown dynamic objects, leveraging a hybrid target model and adaptive grasp generation to handle challenging scenarios like conveyor belt and human-robot handover.

Résumé

The proposed dynamic grasping framework consists of two asynchronous processes: Target Model Generation and Grasp Control.
Target Model Generation:

Tracks the target object using a visual object tracker and constructs a point cloud model by fusing recent observations.
Applies post-processing techniques like outlier removal and iterative closest point (ICP) alignment to maintain a robust and complete internal model of the target.
Grasp Control:

Utilizes the latest internal model point cloud to generate a set of candidate grasps using the generative grasp synthesis model FFHNet.
Selects the most suitable grasp based on a custom metric that considers both semantic (predicted grasp success) and geometric (pose difference) cues.
Employs a visual servoing control law to guide the robot towards the target grasp pose, compensating for changes in the object's translation and rotation.
Estimates the target's velocity using a Kalman filter and updates the grasp pose in case of missing visual feedback due to tracking loss or ICP failure.
Executes the grasp when the current robot pose is predicted to result in a successful grasp.
The framework is evaluated in two realistic scenarios: grasping objects on a conveyor belt with varying speeds, and human-to-robot handovers. The results demonstrate the effectiveness and robustness of the proposed system, achieving high success rates for a variety of unknown objects in dynamic settings.

Stats

The conveyor belt experiment achieved an overall success rate of 71.7% across 120 grasp attempts on 10 different objects at speeds ranging from 0 to 220 mm/s.
The human-to-robot handover experiment achieved an overall success rate of 77% across 100 grasp attempts on the same 10 objects.

Citations

"To the best of our knowledge, we are the first to tackle this challenging problem of multi-fingered dynamic grasping for unknown objects and introduce a practical framework that can run efficiently on real hardware."
"Though easing the problem and enabling progress, it undermined the complexity of the real world. Aiming to relax these assumptions, we present a dynamic grasping framework for unknown objects in this work, which uses a five-fingered hand with visual servo control and can compensate for external disturbances."

Idées clés tirées de

Multi-fingered Dynamic Grasping for Unknown Objects

by Yannick Burk... à arxiv.org 04-09-2024

https://arxiv.org/pdf/2310.17923.pdf

Questions plus approfondies

How can the target model generation be further improved to increase the robustness and accuracy of the internal representation, especially for objects with complex or symmetrical shapes

To enhance the target model generation process for improved robustness and accuracy, especially for objects with intricate or symmetrical shapes, several strategies can be considered. Firstly, incorporating advanced feature extraction techniques, such as using deep learning models like convolutional neural networks (CNNs) to extract more detailed and discriminative features from the RGB-D data, can help in capturing the nuances of complex object shapes. These features can then be utilized to create a more comprehensive and precise internal model representation.
Furthermore, implementing a multi-view fusion approach can enhance the target model by integrating information from multiple perspectives. By combining data from different viewpoints, the system can create a more complete and detailed representation of the object, reducing the chances of missing critical features or encountering ambiguities in the model. This multi-view fusion can be achieved through techniques like point cloud registration and fusion algorithms, enabling a more holistic understanding of the object's geometry.
Additionally, exploring adaptive downsampling techniques based on the object's characteristics and movement patterns can optimize the point cloud density in the model. By dynamically adjusting the downsampling rate according to the object's complexity and motion dynamics, the system can maintain essential details while efficiently managing computational resources. This adaptive downsampling approach can help in creating a more accurate and efficient target model representation, especially for objects with intricate or symmetrical shapes.

What additional techniques could be explored to handle the failure case of hand-target collisions during the grasp execution phase

To address the failure case of hand-target collisions during the grasp execution phase, several additional techniques can be explored to enhance the system's collision avoidance capabilities. One approach is to integrate real-time collision detection algorithms that can predict potential collisions between the robot hand and the target object. By leveraging sensor data and predictive modeling, the system can proactively adjust the robot's trajectory to avoid collisions during the grasp execution process.
Moreover, implementing tactile feedback sensors on the robot hand can provide valuable information about contact forces and pressures, enabling the system to detect and respond to unexpected interactions with the target object. By incorporating tactile sensing capabilities, the system can dynamically adjust the grasp strategy in real time to prevent collisions and ensure a secure and stable grasp.
Furthermore, exploring advanced motion planning algorithms that consider dynamic obstacles and constraints in the environment can help in generating collision-free trajectories for the robot hand. By integrating sophisticated motion planning techniques, such as probabilistic roadmaps or rapidly exploring random trees, the system can navigate complex environments and execute grasps with enhanced safety and reliability, even in challenging scenarios with potential collision risks.

Can the proposed framework be extended to handle more diverse and challenging scenarios, such as grasping objects in cluttered environments or during human-robot collaboration tasks

The proposed framework can indeed be extended to handle more diverse and challenging scenarios, such as grasping objects in cluttered environments or during human-robot collaboration tasks, by incorporating additional capabilities and adaptive strategies. One key aspect to consider is the integration of environment perception and scene understanding modules that can analyze and interpret complex surroundings. By leveraging advanced sensor technologies like LiDAR or depth cameras, the system can generate detailed 3D maps of cluttered environments and identify obstacles or objects of interest for efficient grasp planning.
Moreover, implementing collaborative robotics techniques that enable seamless interaction between humans and robots can enhance the system's adaptability in human-robot collaboration tasks. By integrating intuitive interfaces, safety mechanisms, and shared autonomy features, the framework can facilitate cooperative grasping tasks and ensure smooth coordination between human operators and robotic systems. Additionally, incorporating reinforcement learning algorithms for adaptive grasping strategies in dynamic and interactive environments can further enhance the system's capabilities to handle diverse scenarios effectively.
Furthermore, exploring hybrid control architectures that combine reactive control with high-level planning can enable the system to react to dynamic changes in the environment while maintaining a coherent grasp strategy. By integrating reactive control loops for real-time adjustments and hierarchical planning modules for task-level decision-making, the framework can adapt to varying scenarios and complexities, making it versatile and robust in challenging operational environments.