Design of the fingers of a soft-rigid robotic gripper adaptable for pinching and vacuum grasping

El projecte es centrarà en el disseny d'una pinça robòtica de dos dits que combini totes dues tecnologies de subjecció, la succió i el pinçament (“pinching”), per a convertir-se en un robot versàtil capaç de treballar amb objectes de formes variades. La pinça estarà equipada per a incloure succió al llarg dels dits. A més, els dits estaran dissenyats de manera que permetin col·locar les ventoses per a diferents tipus de subjecció i, com a pinçament, succió horitzontal i vertical, tant en superfícies planes com corbes. En primer lloc, es realitza un estudi de mercat basat en les solucions existents i els objectes que es desitja agafar per a trobar les millors especificacions. Posteriorment, s'aplica una primera aproximació matemàtica per a tractar de trobar una pinça que realitzi la trajectòria desitjada basada en un únic mecanisme de barres. De l’estudi, s'extreuen algunes conclusions i es decideix fer un canvi d'estratègia. Finalment, es dissenya un prototip basat en mecanismes independents i es dimensiona mitjançant un mètode gràfic. Es mostren els seus resultats, es crea un prototip en 3D i es presenten les conclusionsEl proyecto se centrará en el diseño de una pinza robótica de dos dedos que combine ambas tecnologías de agarre, succión y pinzamiento, para convertirse en un robot versátil capaz de trabajar con objetos de formas variadas. La pinza estará equipada para incluir succión a lo largo de los dedos. Además, los dedos estarán diseñados de forma que permitan colocar las ventosas para distintos tipos de agarre, como pellizcos, succión horizontal y vertical, tanto en superficies planas como curvas. En primer lugar, se realiza un estudio de mercado basado en las soluciones existentes y los objetos que se desea agarrar para encontrar las mejores especificaciones. Posteriormente, se aplica una primera aproximación matemática para tratar de encontrar una pinza capaz de realizar la trayectoria deseada basada en un solo mecanismo de barras. Del estudio, se extraen algunas conclusiones y se decide hacer un cambio de estrategia. Por último, se diseña un prototipo basado en mecanismos independientes y se dimensiona mediante un método gráfico. Se muestran sus resultados, se crea un prototipo en 3D y se presentan las conclusionesThe project will focus on the design of a two-finger robotic gripper that combines both technologies of grasping suction and pinching to become a versatile robot capable of working with varied shape objects. The gripper will be equipped for including suction along the fingers. Also, the fingers will be engineered such that they allow the positioning of the suctioning cups for different types of grasping, including pinching, horizontal and vertical suction, for flat as well as curved surfaces. Firstly, a market study based on existing solutions and desired objects to grasp are done to find the best specifications. Later, a first mathematical approach is applied to try to find a one linkage mechanism that performs the wanted trajectory. From the study, some conclusions are drawn and a change of strategy is decided. Finally, a prototype based on independent mechanisms is designed and dimensioned by a graphical method. Their results are shown, a 3D prototype is created and conclusions are presente

AntGrip -- Boosting parallel plate gripper performance inspired by the internal hairs of ant mandibles

Ants use their mandibles - effectively a two-finger gripper - for a wide range of grasping activities. Here we investigate whether mimicking the internal hairs found on ant mandibles can improve performance of a two-finger parallel plate robot gripper. With bin picking applications in mind, the gripper fingers are long and slim, with interchangeable soft gripping pads that can be hairy or hairless. A total of 2400 video-documented experiments have been conducted, comparing hairless to hairy pads with different hair patterns. Simply by adding hairs, the grasp success rate was increased by at least 29%, and the number of objects that remain securely gripped during manipulation more than doubled. This result not only advances the state of the art in grasping technology, but also provides novel insight into the mechanical role of mandible hairs in ant biology

Grasp Point Optimization and Leakage-Compliant Dimensioning of Energy-Efficient Vacuum-Based Gripping Systems

Vacuum-based handling, used in many applications and industries, offers great flexibility and fast handling processes. However, due to significant energy conversion losses from electrical energy to the useable suction flow, vacuum-based handling is highly energy-inefficient. In preliminary work, we showed that our grasp optimization method offers the potential to save at least 50% of energy by a targeted placement of individual suction cups on the part to be handled. By considering the leakage between gripper and object, this paper aims to extend the grasp optimization method by predicting the effective compressed air consumption depending on object surface roughness, gripper diameter and gripper count. Through balancing of the target pressure difference and the leakage tolerance in combination with the gripper count and gripper diameter, significant reductions of the compressed air, use and therefore the overall energy consumption, can be achieved. With knowledge about the gripper-specific leakage behavior, in the future it will be straightforward for system integrators to minimize the need for oversizing due to process-related uncertainties and therefore to provide application-specific and energy-optimized handling solutions to their customers