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Dexterous bimanual manipulation

The fingers of the Tracebot robotic gripper. © R.Poulverel/CEA
In robotics, automating complex manual tasks involving a variety of parts in unstructured environments presents major scientific and industrial challenges. CEA-List developed a dexterous bimanual manipulation system to respond to these use cases. The system’s multiple reconfigurable fingers are equipped with multimode perception capabilities. The system can carry out 80 different grips, using finely controlled force, and detect slippage.

CEA-List has been designing and developing control systems for dexterous robotic grippers for several years. Intended for a wide variety of industrial use cases, these systems can automate tasks that require the dexterity of both human hands. They are particularly well-suited to the challenges of unstructured environments. This research responds to pressing societal issues like improving working conditions and reducing the difficulty of physically-taxing job tasks.

In research for the European H2020 Tracebot project, the system proved to be almost as efficient as human manipulation on a bimanual manipulation task.

Each of the system’s reconfigurable grippers has four fingers, each with three phalanges equipped with hybrid piezoelectric-piezoresistive touch sensors. This architecture offers eighteen degrees of freedom, fourteen of which are actuated. CEA-List provided the grippers and controller; CEA-Leti provided the sensors.

Exceptional tightening force: 20 N at the finger (the gripper can lift 2 kg with a single finger). © CEA

Kinesthetic, touch, and visual information are combined in multi-mode perception. The touch sensors detect critical events like object slippage, insertion, and assembly. Supervised learning algorithms classify these events, enabling safer and more efficient interaction with the environment. Dexterous manipulation—the ability to perform precise movements and adapt them—is the main pillar of this advance. High-performance, low-friction actuators enable 80 different grips, attesting to the system’s flexibility and ability to handle a variety of objects. The controller provides a high degree of precision in both position and force, supporting smarter automation that places fewer restrictions on workers.

By reducing physical strain and improving product quality, these technologies, used in combination, could transform manufacturing, logistics, healthcare, and other industries. Use cases in other fields in which precision is crucial—medical robotics and assistance for the elderly—are also possible.

The gripper can adapt to objects of various shapes and sizes, maintaining the same level of accuracy on small objects. © R.Poulverel/CEA

Major projects

In research for the EU H2020 Tracebot project, the CEA developed a bimanual manipulation station with two grippers fitted to collaborative robotic arms. This station was integrated into a demonstrator at project partner ASTECH. The system was tested on a real-world medical equipment handling task that addresses one of today’s major challenges: automating sterile kit production.

Upcoming research will address bimanual robotic manipulation planning strategies using reinforcement learning and other methods.

The hardware and software are expected to be transferred to FINRIP as part of an R&D partnership.

 

Patent

  • Manipulation robotique et glissement, Grossard Mathieu; Aloui Saifeddine; Ayral Theo DD24102 CJ

Flagship publications

  • “Comprehensive analysis of human gesture: application for the specification of dexterous robotic grippers“ 2023: J. M. Escorcia, M. Grossard, F. Gosselin ASME Journal of Mechanical Design, pages 041408, vol. 145-2023
  • “Spectro-temporal RNN structure for object slip detection using piezoelectric tactile sensor in robotic grasping“ 2023: T. Ayral, S. Aloui, M. Grossard IEEE/ASME AIM 2023

Contributed to this article:

  • Mathieu GROSSARD, research director at CEA-List
  • Clémence DUBOIS, engineer-researcher at CEA-List

With this new generation of multi-fingered grippers, tasks previously too complex to be automated will no longer have to be done manually.

Rebecca Cabean

MATHIEU GROSSARD

RESEARCH DIRECTOR — CEA-List

Multi-mode perception allows a gripper to interact dexterously with its environment.

Rebecca Cabean

CLÉMENCE DUBOIS

RESEARCH ENGINEER — CEA-List