Soft Hands with Embodied Constraints: The Soft ScoopGripper

Salvietti, Gionata; Iqbal, Zubair; Malvezzi, Monica; Eslami, Taban; Prattichizzo, Domenico

doi:10.1109/icra.2019.8793563

Cited by 16 publications

(16 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the presented example, an assembly task is performed and the setup is composed of two grippers, the Co-Gripper (Salvietti et al, 2018) and the Soft ScoopGripper (Salvietti et al, 2019), a collaborative robot arm, the Sawyer Robot (Rethink Robotics), and a customized tool changer, that is described in Section 3. The scenario shown in Figure 2, however, is just used to give an idea of the possibilities offered by detachable grippers in highly flexible human-robot collaborative tasks, and can be generalized to other applications and other devices.…”

Section: Detachable Grippers Conceptmentioning

confidence: 99%

Detachable Robotic Grippers for Human-Robot Collaboration

et al. 2021

View full text Add to dashboard Cite

Collaborative robots promise to add flexibility to production cells thanks to the fact that they can work not only close to humans but also with humans. The possibility of a direct physical interaction between humans and robots allows to perform operations that were inconceivable with industrial robots. Collaborative soft grippers have been recently introduced to extend this possibility beyond the robot end-effector, making humans able to directly act on robotic hands. In this work, we propose to exploit collaborative grippers in a novel paradigm in which these devices can be easily attached and detached from the robot arm and used also independently from it. This is possible only with self-powered hands, that are still quite uncommon in the market. In the presented paradigm not only hands can be attached/detached to/from the robot end-effector as if they were simple tools, but they can also remain active and fully functional after detachment. This ensures all the advantages brought in by tool changers, that allow for quick and possibly automatic tool exchange at the robot end-effector, but also gives the possibility of using the hand capabilities and degrees of freedom without the need of an arm or of external power supplies. In this paper, the concept of detachable robotic grippers is introduced and demonstrated through two illustrative tasks conducted with a new tool changer designed for collaborative grippers. The novel tool changer embeds electromagnets that are used to add safety during attach/detach operations. The activation of the electromagnets is controlled through a wearable interface capable of providing tactile feedback. The usability of the system is confirmed by the evaluations of 12 users.

show abstract

Section: Detachable Grippers Conceptmentioning

confidence: 99%

Detachable Robotic Grippers for Human-Robot Collaboration

et al. 2021

View full text Add to dashboard Cite

show abstract

“…in an active way to support the hand in reaching the object or to reposition it [37]. In [38], a flat active surface was added to an underactuated modular gripper to embed on the hand a constraint surface that could help in grasping and manipulating objects. In the solution presented in [38] the flat surface was approximately rigid and had only one actuated DoF at its base allowing a limited bending.…”

Section: The Scoop Handmentioning

confidence: 99%

“…In this paper, we present an improvement of the idea proposed in [38], guided by: (i) a further exploitation of system compliance by means of flexible materials and (ii) providing a closure motion also to the flat embedded constraint. Different solutions were evaluated and compared, in terms of complexity, payload, versatility.…”

Section: Paper Contributionmentioning

confidence: 99%

See 1 more Smart Citation

Design of Soft Grippers with Modular Actuated Embedded Constraints

et al. 2020

View full text Add to dashboard Cite

Underactuated, modular and compliant hands and grippers are interesting solutions in grasping and manipulation tasks due to their robustness, versatility, and adaptability to uncertainties. However, this type of robotic hand does not usually have enough dexterity in grasping. The implementation of some specific features that can be represented as “embedded constraints” allows to reduce uncertainty and to exploit the role of the environment during the grasp. An example that has these characteristics is the Soft ScoopGripper a gripper that has a rigid flat surface in addition to a pair of modular fingers. In this paper, we propose an upgraded version of the Soft ScoopGripper, developed starting from the limits shown by the starting device. The new design exploits a modular structure to increase the adaptability to the shape of the objects that have to be grasped. In the proposed device the embedded constraint is no rigid neither unactuated and is composed of an alternation of rigid and soft modules, which increase versatility. Moreover, the use of soft material such as thermoplastic polyurethane (TPU) reduces the risk of damage to the object being grasped. In the paper, the main design choices have been exploited and a finite element method (FEM) analysis through static simulation supports a characterization of the proposed solution. A complete prototype and some preliminary tests have been presented.

show abstract

“…Flip-and-pinch grasps were achieved with an open-loop control strategy using an underactuated gripper in Odhner et al ( 2013 ). In Babin and Gosselin ( 2018 ) and Salvietti et al ( 2019 ), instead, flat objects were picked up by using dedicated tools that, similarly to a scoop, can slide under the object and lift it.…”

Section: Introductionmentioning

confidence: 99%

Exploiting Robot Hand Compliance and Environmental Constraints for Edge Grasps

et al. 2019

View full text Add to dashboard Cite

This paper presents a method to grasp objects that cannot be picked directly from a table, using a soft, underactuated hand. These grasps are achieved by dragging the object to the edge of a table, and grasping it from the protruding part, performing so-called slide-to-edge grasps. This type of approach, which uses the environment to facilitate the grasp, is named Environmental Constraint Exploitation (ECE), and has been shown to improve the robustness of grasps while reducing the planning effort. The paper proposes two strategies, namely Continuous Slide and Grasp and Pivot and Re-Grasp, that are designed to deal with different objects. In the first strategy, the hand is positioned over the object and assumed to stick to it during the sliding until the edge, where the fingers wrap around the object and pick it up. In the second strategy, instead, the sliding motion is performed using pivoting, and thus the object is allowed to rotate with respect to the hand that drags it toward the edge. Then, as soon as the object reaches the desired position, the hand detaches from the object and moves to grasp the object from the side. In both strategies, the hand positioning for grasping the object is implemented using a recently proposed functional model for soft hands, the closure signature, whereas the sliding motion on the table is executed by using a hybrid force-velocity controller. We conducted 320 grasping trials with 16 different objects using a soft hand attached to a collaborative robot arm. Experiments showed that the Continuous Slide and Grasp is more suitable for small objects (e.g., a credit card), whereas the Pivot and Re-Grasp performs better with larger objects (e.g., a big book). The gathered data were used to train a classifier that selects the most suitable strategy to use, according to the object size and weight. Implementing ECE strategies with soft hands is a first step toward their use in real-world scenarios, where the environment should be seen more as a help than as a hindrance.

show abstract

Soft Hands with Embodied Constraints: The Soft ScoopGripper

Cited by 16 publications

References 15 publications

Detachable Robotic Grippers for Human-Robot Collaboration

Detachable Robotic Grippers for Human-Robot Collaboration

Design of Soft Grippers with Modular Actuated Embedded Constraints

Exploiting Robot Hand Compliance and Environmental Constraints for Edge Grasps

Contact Info

Product

Resources

About