Membrane surface lets small robots move tiny objects precisely
Making Waves: A Membrane-Coupled Delta Array for Manipulating Objects Below the Actuator Spacing
Robotics
Summary
Normally, small robots with many arms can only move objects bigger than the distance between their arms. The authors connected 64 tiny robots through a stretchy fabric, creating one smooth surface to move even smaller objects. They taught the system to control parts of the surface for precise moves, working on multiple objects at once. Their setup can handle items between 15mm and 90mm, smaller than before, and works well on real hardware.
What this means in practice
- •For precision robotics engineers: Build manipulation systems that handle objects smaller than individual robot parts by using membrane-coupled arrays.
- •For manufacturing automation teams: Improve sorting and placement of small parts by deploying arrays that create continuous contact surfaces.
Authors
Bailey Dacre, Andrés Faíña, Oliver Kroemer, Zeynep Temel
Abstract
Distributed manipulator systems manipulate objects through the coordinated motion of many actuators. However, an object must be supported by several actuators at once, so the centre-to-centre actuator spacing imposes a hard lower bound on manipulable object size. We remove this bound by coupling the end-effectors of an 8 x 8 array of three degrees-of-freedom delta robots with a stretchable fabric, turning 64 discrete contacts into a continuous surface capable of manipulating objects smaller than the actuator spacing. Viewing the array as a displacement field over that surface, we investigate local quasi-static and cyclic fields as manipulation primitives. These primitives can be applied globally across the array or locally confined around each tracked object to independently manipulate several objects in parallel. We then train a policy acting on low-order discrete cosine transform coefficients: at equal action dimension, commanding a nineteen-delta neighbourhood halves the placement error of commanding the whole array. The policy transfers to hardware without adaptation at 76% success. The platform manipulates objects from 15mm-90mm, a six-fold range spanning both sides of the actuator spacing, 43.3mm, on a single surface.