Dexterous Manipulation of Deformable Objects via Pneumatic Gripping: Lifting by One End

TL;DR

The paper tackles the problem of automatically manipulating deformable textiles on robotic lines, where single-arm grasping and airflow from pneumatic grippers can hinder lifting. It introduces a dexterous lifting approach that reorients and positions a pneumatic gripper during the lift, guided by a trajectory planning framework modeling the edge as a deformable curve to minimize sliding and depressurization. The method, validated on four textile materials with varying mass, friction, and porosity, achieves a 19%–76% reduction in required grip pressure and suppresses airflow-induced vibrations, enabling successful lifts from a single edge. This work paves the way for more accessible, energy-efficient textile handling in automated production, with future extensions toward vision-based optimization and broader object geometries.

Abstract

Manipulating deformable objects in robotic cells is often costly and not widely accessible. However, the use of localized pneumatic gripping systems can enhance accessibility. Current methods that use pneumatic grippers to handle deformable objects struggle with effective lifting. This paper introduces a method for the dexterous lifting of textile deformable objects from one edge, utilizing a previously developed gripper designed for flexible and porous materials. By precisely adjusting the orientation and position of the gripper during the lifting process, we were able to significantly reduce necessary gripping force and minimize object vibration caused by airflow. This method was tested and validated on four materials with varying mass, friction, and flexibility. The proposed approach facilitates the lifting of deformable objects from a conveyor or automated line, even when only one edge is accessible for grasping. Future work will involve integrating a vision system to optimize the manipulation of deformable objects with more complex shapes.

Figures (16)

• Figure 1: Dexterous lifting of the textile object by one end with pneumatic gripper (Gripping Device for Flexible and Porous Materials Mykhailyshyn2022gripper with 185 kPa supply pressure).
• Figure 2: Failing classical vertical lifting using a pneumatic gripping device for porous and textile objects: (a) thin denim cotton; (b) 600-denier cordura outdoor canvas waterproof fabric.
• Figure 3: Existing and studied methods of grasping/manipulating deformable objects: (a) automated stage of the textile cutting machine (Serkon); (b) commercially available pneumatic grasping system for deformable objects Airborne and Schmalz; (c) manipulation deformable objects using pneumatic grippers with planar contacts and plane.
• Figure 4: Scheme of the vertical lifting of the object (View A in Fig. \ref{['fig1_3']}): $C$ - distance between the edge of the deformable object to the gripper; $D$ - diameter of the gripper; $L$ - length of the deformable object; $z_1$ - coordinates of point A along the $z$-axis; $l_1$ - length of the deformed segment AO of the object projected on the $x$-axis; $l_2$ - length of the object segment lying on the covering; $\alpha$ - angle of gripper orientation relative to the $x$-axis; $\vec{H}$ - tension force formed by the friction force of the lying segment of the object ($l_2$); $\vec{Q}$ - force is equivalent to the mass of the segment of the object AO; $\vec{T}(x)$ - tension force at point A that equivalent force $\vec{Q}$.
• Figure 5: Changing the position and shape of the deformable material as it moves upward ($L = 1$ m, $q = 1$ N/m, and $k = 0.2$)